Changing boundaries: Overcoming modifiable areal unit problems related to unemployment data in South Africa.

The longitudinal comparison of census data in spatial format is often problematic because of changes in administrative boundaries. Such shifting boundaries are referred to as the modifiable areal unit problem (MAUP). This article utilises unemployment data between 1991 and 2007 in South Africa to illustrate the challenge and proposes ways to overcome it. Various censuses in South Africa use different reporting geographies. Unemployment data for magisterial districts of census 1991 and 1996 were re-modelled to the 2005 municipal boundaries. This article showed that areal interpolation to a common administrative boundary could overcome these reporting obstacles. The results confirmed more accurate interpolations in rural areas with standard errors below 3300. Conversely, the largest errors were recorded in the metropolitan areas. Huge increases in unemployment between 1996 and 2001 statistics were also evident, especially in the metropolitan areas. Although such areas are more complex in nature, making it more difficult to accurately calculate census data, the increase in unemployment could also be the result of census taking methods. The article concludes that socio-economic data should be available at the smallest possible geographic area to ensure more accurate results in interpolation. It also recommends that new output areas be conceptualised to create a seamless database of census data from 1991 to 2011 in South Africa.NCS201

Unemployment in South Africa: Building a Spatio-temporal Understanding

The spatial understanding of unemployment in South Africa is often limited to provinces. This paper explores ways to integrate unemployment data from 1991 to 2007 to obtain a spatially more detailed understanding of the phenomenon. Creating such a temporal GIS is challenging because of the changing administrative boundaries and this phenomenon is part of the modifiable areal unit problem (MAUP). The MAUP was overcome by using proportional aggregation to the 2005 municipal boundaries. The  unemployment data were analysed spatially through mapping standard deviation intervals and spatial autocorrelation. Unemployment showed a spatial pattern over time in South Africa and municipalities with high unemployment figures over time were spatially concentrated. Furthermore, it is recommended that census data should be released at a small area level to allow more accurate comparison of socio-economic data over time

Determination of Effective Permittivity and Permeability of Metamaterials from Reflection and Transmission Coefficients

We analyze the reflection and transmission coefficients calculated from transfer matrix simulations on finite lenghts of electromagnetic metamaterials, to determine the effective permittivity and permeability. We perform this analysis on structures composed of periodic arrangements of wires, split ring resonators (SRRs) and both wires and SRRs. We find the recovered frequency-dependent permittivity and permeability are entirely consistent with analytic expressions predicted by effective medium arguments. Of particular relevance are that a wire medium exhibits a frequency region in which the real part of permittivity is negative, and SRRs produce a frequency region in which the real part of permeability is negative. In the combination structure, at frequencies where both the recovered real part of permittivity and permeability are simultaneously negative, the real part of the index-of-refraction is found also to be unambigously negative.Comment: *.pdf file, 5 figure

Inflammatory bowel disease: the role of inflammatory cytokine gene polymorphisms.

The mechanisms responsible for development of inflammatory bowel disease (IBD) have not been fully elucidated, although the main cause of disease pathology is attributed to up-regulated inflammatory processes. The aim of this study was to investigate frequencies of polymorphisms in genes encoding pro-inflammatory and anti-inflammatory markers in IBD patients and controls. We determined genotypes of patients with IBD (n= 172) and healthy controls (n= 389) for polymorphisms in genes encoding various cytokines (interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF), IL-10, IL-1 receptor antagonist). Association of these genotypes to disease incidence and pathophysiology was investigated. No strong association was found with occurrence of IBD. Variation was observed between the ulcerative colitis study group and the control population for the TNF-alpha-308 polymorphism (p= 0.0135). There was also variation in the frequency of IL-6-174 and TNF-alpha-308 genotypes in the ulcerative colitis group compared with the Crohn's disease group (p= 0.01). We concluded that polymorphisms in inflammatory genes are associated with variations in IBD phenotype and disease susceptibility. Whether the polymorphisms are directly involved in regulating cytokine production, and consequently pathophysiology of IBD, or serve merely as markers in linkage disequilibrium with susceptibility genes remains unclear

Phase changes in f-electron metals: discrepancies between experiment and theory

Using a diamond anvil cell, phase transformation and RT equation of state for lanthanide and actinides were studied to multimegabars. Experimental data are compared with theoretical crystal structural changes and P-V relations. A generalized trend for phase transformations in lanthanides can be seen, which has broad agreement with theory. Broad agreement is also seen for structural changes in lighter actinides, with some discrepancies. It is concluded that an accurate, robust theoretical base for predicting phase transformations in the f- electron metals can be developed by incorporating DAC data as markers for fine tuning the theory

Therapy of established B16-F10 melanoma tumors by a single vaccination of CTL/T helper peptides in VacciMax(®)

BACKGROUND: Melanoma tumors are known to express antigens that usually induce weak immune responses of short duration. Expression of both tumor-associated antigens p53 and TRP2 by melanoma cells raises the possibility of simultaneously targeting more than one antigen in a therapeutic vaccine. In this report, we show that VacciMax(® )(VM), a novel liposome-based vaccine delivery platform, can increase the immunogenicity of melanoma associated antigens, resulting in tumor elimination. METHODS: C57BL/6 mice bearing B16-F10 melanoma tumors were vaccinated subcutaneously 6 days post tumor implantation with a mixture of synthetic peptides (modified p53: 232–240, TRP-2: 181–188 and PADRE) and CpG. Tumor growth was monitored and antigen-specific splenocyte responses were assayed by ELISPOT. RESULTS: Vaccine formulated in VM increased the number of both TRP2- and p53-specific IFN-γ producing splenocytes following a single vaccination. Vaccine formulated without VM resulted only in enhanced IFN-γ producing splenocytes to one CTL epitopes (TRP2:180–188), suggesting that VM overcomes antigen dominance and enhances immunogenicity of multiple epitopes. Vaccination of mice bearing 6-day old B16-F10 tumors with both TRP2 and p53-peptides formulated in VM successfully eradicated tumors in all mice. A control vaccine which contained all ingredients except liposomes resulted in eradication of tumors in no more than 20% of mice. CONCLUSION: A single administration of VM is capable of inducing an effective CTL response to multiple tumor-associated antigens. The responses generated were able to reject 6-day old B16-F10 tumors

Rejection of large HPV-16 expressing tumors in aged mice by a single immunization of VacciMax® encapsulated CTL/T helper peptides

The incidence of cancer increases significantly in later life, yet few pre-clinical studies of cancer immunotherapy use mice of advanced age. A novel vaccine delivery platform (VacciMax®,VM) is described that encapsulates antigens and adjuvants in multilamellar liposomes in a water-in-oil emulsion. The therapeutic potential of VM-based vaccines administered as a single dose was tested in HLA-A2 transgenic mice of advanced age (48–58 weeks old) bearing large palpable TC1/A2 tumors. The VM-based vaccines contained one or more peptides having human CTL epitopes derived from HPV 16 E6 and E7. VM formulations contained a single peptide, a mixture of four peptides or the same four peptides linked together in a single long peptide. All VM formulations contained PADRE and CpG as adjuvants and ISA51 as the hydrophobic component of the water-in-oil emulsion. VM-formulated vaccines containing the four peptides as a mixture or linked together in one long peptide eradicated 19-day old established tumors within 21 days of immunization. Peptide-specific cytotoxic cellular responses were confirmed by ELISPOT and intracellular staining for IFN-γ producing CD8+ T cells. Mice rendered tumor-free by vaccination were re-challenged in the opposite flank with 10 million HLF-16 tumor cells, another HLA-A2/E6/E7 expressing tumor cell line. None of these mice developed tumors following the re-challenge. In summary, this report describes a VM-formulated therapeutic vaccine with the following unprecedented outcome: a) eradication of large tumors (> 700 mm3) b) in mice of advanced age c) in less than three weeks post-immunization d) following a single vaccination

Immunological characterization of chromogranins A and B and secretogranin II in the bovine pancreatic islet

Antisera against chromogranin A and B and secretogranin II were used for analysing the bovine pancreas by immunoblotting and immunohistochemistry. All three antigens were found in extracts of fetal pancreas by one dimensional immunoblotting. A comparison with the soluble proteins of chromaffin granules revealed that in adrenal medulla and in pancreas antigens which migrated identically in electrophoresis were present. In immunohistochemistry, chromogranin A was found in all pancreatic endocrine cell types with the exception of most pancreatic polypeptide-(PP-) producing cells. For chromogranin B, only a faint immunostaining was obtained. For secretorgranin II, A-and B-cells were faintly positive, whereas the majority of PP-cells exhibited a strong immunostaining for this antigen. These results establish that chromogranins A and B and secretogranin II are present in the endocrine pancreas, but that they exhibit a distinct cellular localization

Electromyographic Responses from the Vastus Medialis during Isometric Muscle Actions

This study examined the electromyographic (EMG) responses from the vastus medialis (VM) for electrodes placed over and away from the innervation zone (IZ) during a maximal voluntary isometric contraction (MVIC) and sustained, submaximal isometric muscle action. A linear electrode array was placed on the VM to identify the IZ and muscle fiber pennation angle during an MVIC and sustained isometric muscle action at 50 % MVIC. EMG amplitude and frequency parameters were determined from 7 bipolar channels of the electrode array, including over the IZ, as well as 10 mm, 20 mm and 30 mm proximal and distal to the IZ. There were no differences between the channels for the patterns of responses for EMG amplitude or mean power frequency during the sustained, submaximal isometric muscle action; however, there were differences between channels during the MVIC. The results of the present study supported the need to standardize the placement of electrodes on the VM for the assessment of EMG amplitude and mean power frequency. Based on the current findings, it is recommended that electrode placements be distal to the IZ and aligned with the muscle fiber pennation angle during MVICs, as well as sustained, submaximal isometric muscle actions