George E. Mathews

Oral health and coronary heart disease

BackgroundIt is well documented that there is some correlation between poor oral health in the form of periodontal disease and coronary heart disease (CHD). It is unclear whether this correlation is due to a causal relationship or shared underlying disorder such as inflammation. A suitable integrated model of the CHD pathogenetic pathways relevant to periodontal disease may help to elucidate the association. Such a model is currently not available in literature.MethodsA previously developed integrated model of CHD was used to investigate potential pathogenetic pathways linking periodontal disease to CHD biomarkers.ResultsThe integrated model was created to provide insight into possible higher-order biological interactions underlying CHD and periodontal disease. In order to simplify these interactions a novel ‘connection graph’ was developed. It quantitatively illustrates the relationship between periodontal disease and various serological biomarkers of CHD. The pathogenesis of periodontitis shows various possible pathways which could link periodontitis to CHD pathogenesis.ConclusionAn integrated model of CHD was developed which provides a summary of the potential CHD effects of periodontal disease. Further research must refine and validate the model.

Household photovoltaics — A worthwhile investment?

A combination of factors, including recent advances in Small-Scale Energy Generation (SSEG) legislation as well as decreases in the cost of photovoltaic cells and batteries, have recently made investment in Solar Photovoltaic energy for a consumers household more appealing. In order to quantify the benefits of investing in such an installation a simulation model was created to test the financial feasibility of different configurations of such an installation. This model was then used to simulate several different configurations of battery and photovoltaic installations for a medium- and high-income urban household. From these simulations it was found that a household pure photovoltaic installation is economically feasible, with payback periods for medium- and high income households being 7.52 and 6.94 years respectively. SSEG contracts with the municipality were also found to increase the economic benefits to the consumer. This was largely due to the consumers ability to use the municipal grid as a ‘battery’ and offset power generation to peak-use times with an SSEG contract.

Photovoltaic cells - the hot new investment?

A combination of factors, including recent decreases in the cost of photovoltaic cells and batteries as well as the governments Renewable Energy Independent Power Producer Procurement Program, have recently made investment in Solar Photovoltaic energy facilities more appealing.

A hypothetical method for controlling highly glycolytic cancers and metastases

Most proliferating cancer cells and cancer-associated tumor stroma have an upregulated glucose energy demand in relation to normal cells. Cancer cells are further less metabolically flexible than normal cells. They can therefore not survive metabolic stress as well as normal cells can. Metabolic deprivation thus provides a potential therapeutic window. Unfortunately, current glucose blockers have toxicity problems. An alternative way to reduce a cancer patients blood glucose (BG), for a short-term period to very low levels, without the concomitant toxicity, is hypothesized in this paper. In vitro tests have shown that short-term BG deprivation to 2 mmol/L for 180 min is an effective cancer treatment. This level of hypoglycaemia can be maintained in vivo with a combination of very low-dose insulin and the suppression of the glucose counter-regulation system. Such suppression can be safely achieved by the infusion of somatostatin and a combination of both α and β-blockers. The proposed short-term in vivo method, was shown to be non-toxic and safe for non-cancer patients. The next step is to test the effect of the proposed method on cancer patients. It is also suggested to incorporate well-known, long-term BG deprivation treatments to achieve maximum effect.

The integrated effect of moderate exercise on coronary heart disease

Summary Background: Moderate exercise is associated with a lower risk for coronary heart disease (CHD). A suitable integrated model of the CHD pathogenetic pathways relevant to moderate exercise may help to elucidate this association. Such a model is currently not available in the literature. Methods: An integrated model of CHD was developed and used to investigate pathogenetic pathways of importance between exercise and CHD. Using biomarker relative-risk data, the pathogenetic effects are representable as measurable effects based on changes in biomarkers. Results: The integrated model provides insight into higherorder interactions underlying the associations between CHD and moderate exercise. A novel ‘connection graph’ was developed, which simplifies these interactions. It quantitatively illustrates the relationship between moderate exercise and various serological biomarkers of CHD. The connection graph of moderate exercise elucidates all the possible integrated actions through which risk reduction may occur. Conclusion: An integrated model of CHD provides a summary of the effects of moderate exercise on CHD. It also shows the importance of each CHD pathway that moderate exercise influences. The CHD risk-reducing effects of exercise appear to be primarily driven by decreased inflammation and altered metabolism.

A cost comparison of different energy saving measures in a household

Many households do not have the financial capacity to afford to implement energy savings measures across the board. This paper therefore compared four different energy savings measures and compared their payback periods in order to ascertain the most effective measures for a consumers budget.

A redesign of a mobile solar water heater for rural housing in Southern Africa

The low-income rural population of Southern Africa faces a daily problem due to the difficulty of collecting and transporting water from communal water sources. Another problem is that the energy sources generally used to heat this domestic water have become scarce and expensive. It was therefore decided to design an affordable device that could assist with the transportation and heating of water in rural areas. The decision was made to use solar power for the water heating. Initial prototypes were therefore designed, manufactured and tested in the early 2000s. It was thereby demonstrated that water could be heated to an average of 60 °C by mid-afternoon. This is beneficial since several micro-organisms, including V. Cholerae, are destroyed after an hour at 45 °C. Water at 40 °C was also still available at 20:00 in the evening. Further design changes were then implemented in 2014–15 in order to address the issues found during this testing phase as well as to reduce the cost per unit of the design. This new design should be able to heat water to an average of 52°C by mid-afternoon and allow water at 40 °C to still be available at 20:00 in the evening.

The benefits of energy efficiency programs - comparing Germany with South Africa

Over the past two decades the world has become much more conscious of the disadvantages of rampant energy use. To this end many countries have adopted strategies and policies meant to reduce their energy usage and consequently reduce their global energy footprint. The German government is often praised for its stance on reducing energy usage. Therefore, this paper will explore the energy efficiency strategy implemented by the German government. The paper will also explore the current energy efficiency strategies implemented by the South African government and industry as well as the results thereof. This should allow for a comparison of whether the current South African policies compare favourably to that of a first world country that is serious about energy efficiency. From this comparison it is obvious that the South African energy efficiency policy strategy compares favourably.

A mobile design application for energy efficient buildings

With the current electricity problems facing South Africa and the rise of the green building initiative internationally, energy-efficient buildings have become much more popular. Architects form an integral link in the design of these energy-efficient buildings. Energy-efficient building design strategies therefore, require both architects and engineers to work closely together in optimising the building design. However, this is not always practical in real world terms. Architects must therefore, be able to perform a preliminary thermal analysis if energy efficient design strategies are to succeed. Existing tools do not however cater for architects to do a fast preliminary thermal analysis during the initial design phase. They also often require fixed computer systems. A need therefore exists for a simplified mobile thermal design application for architects. A suitable program was developed in the late 1990s for use on personal computers. This article discusses the evaluation of translating this program to a mobile application.

Proposed installation of a low-cost ceiling system in low cost housing

Existing formal low-cost houses in South Africa have been shown to be very thermally and energy inefficient. This is problematic for the country since the government has built roughly 2.8 million of these houses to date. Inefficiency in these houses can be effectively addressed by installing ceilings, but the cost thereof is unfortunately too high to be affordable to the applicable sector of the population. New options need to be considered to reduce costs. Research has shown that practically any material can be used as a ceiling if it provides a barrier to heat flow and eliminates infiltration. The material should ideally possess good thermal properties and comply with standard building regulations, but most importantly, it must be very cheap and easy to install. The low-cost ceiling proposed in this paper has all of these attributes, and installation thereof could result in substantial energy savings, improved indoor comfort, and a better quality of life.