On Some Epistemological Problems of Software Engineering

The paper addresses some misconceptions of Software Engineering, requirements analysis and modelling in particular, due to underlying epistemological flaws., e.g. the believe that the system analyst\u27s task be simlar to that of a natural scientist\u27s. The fundamental issues, constitution of objects and signs, conceptualization and definability, are discussed. It comes out that the paradoxical situation of software engineering is having to formalize what cannot be formalized. This is reflected in the fuzzy notion of \u27model\u27 in general as well as in the epistemological presumptions of \u27object oriented modelling\u27 in particular. The paradigm of \u27objective modelling\u27 has to be replaced by a paradigm of \u27purposive description\u27 shifting the focus of Software Engineering research to non-formal methodologies

Do organic inputs alter resistance and resilience of soil microbial community to drying?

Abstract not availableE.-L. Ng, A.F. Patti, M.T. Rose, C.R. Schefe, R.J. Smernik, T.R. Cavagnar

Functional stoichiometry of soil microbial communities after amendment with stabilised organic matter

Abstract not availableEe Ling Ng, Antonio Frank Patti, Michael Timothy Rose, Cassandra Rae Schefe, Kevin Wilkinson, Timothy Richard Cavagnar

Does the chemical nature of soil carbon drive the structure and functioning of soil microbial communities?

Abstract not availableE.-L. Ng, A.F. Patti, M.T. Rose, C.R. Schefe, K. Wilkinson, R.J. Smernik, T.R.Cavagnar

Increased Glutathione Synthesis Following Nrf2 Activation by Vanadyl Sulfate in Human Chang Liver Cells

Jeju ground water, containing vanadium compounds, was shown to increase glutathione (GSH) levels as determined by a colorimetric assay and confocal microscopy. To investigate whether the effects of Jeju ground water on GSH were specifically mediated by vanadium compounds, human Chang liver cells were incubated for 10 passages in media containing deionized distilled water (DDW), Jeju ground water (S1 and S3), and vanadyl sulfate (VOSO4). Vanadyl sulfate scavenged superoxide anion, hydroxyl radical and intracellular reactive oxygen species. Vanadyl sulfate effectively increased cellular GSH level and up-regulated mRNA and protein expression of a catalytic subunit of glutamate cysteine ligase (GCLC), which is involved in GSH synthesis. The induction of GCLC expression by vanadyl sulfate was found to be mediated by transcription factor erythroid transcription factor NF-E2 (Nrf2), which critically regulates GCLC by binding to the antioxidant response elements (AREs). Vanadyl sulfate treatment increased the nuclear translocation of Nrf2 and the accumulation of phosphorylated Nrf2. Extracellular regulated kinase (ERK) contributed to ARE-driven GCLC expression via Nrf2 activation. Vanadyl sulfate induced the expression of the active phospho form of ERK. Taken together, these results suggest that the increase in GSH level by Jeju ground water is, at least in part, due to the effects of vanadyl sulfate via the Nrf2-mediated induction of GCLC

The Prismatic Topography of Pinctada maxima Shell Retains Stem Cell Multipotency and Plasticity In Vitro

Abstract The shell of the bivalve mollusc Pinctada maxima is composed of the calcium carbonate polymorphs calcite and aragonite (nacre). Mother‐of‐pearl, or nacre, induces vertebrate cells to undergo osteogenesis and has good osteointegrative qualities in vivo. The calcite counterpart, however, is less researched in terms of the response of vertebrate cells. This study shows that isolation of calcite surface topography from the inherent chemistry allows viable long‐term culture of bone marrow derived mesenchymal stem cells (MSCs). Self‐renewal is evident from the increased gene expression of the self‐renewal markers CD63, CD166, and CD271 indicating that cells cultured on the calcite topography maintain their stem cell phenotype. MSCs also retain their multipotency and can undergo successful differentiation into osteoblasts and adipocytes. When directed to adipogenesis, MSCs cultured on prism replicas are more amenable to differentiation than MSCs cultured on tissue culture polystyrene indicating a higher degree of plasticity in MSCs growing on calcite P. maxima prismatic topography. The study highlights the potential of the calcite topography of P. maxima as a biomimetic design for supporting expansion of MSC populations in vitro, which is of fundamental importance if it meets the demands for autologous MSCs for therapeutic use

Genes Influencing Circadian Differences in Blood Pressure in Hypertensive Mice

Essential hypertension is a common multifactorial heritable condition in which increased sympathetic outflow from the central nervous system is involved in the elevation in blood pressure (BP), as well as the exaggerated morning surge in BP that is a risk factor for myocardial infarction and stroke in hypertensive patients. The Schlager BPH/2J mouse is a genetic model of hypertension in which increased sympathetic outflow from the hypothalamus has an important etiological role in the elevation of BP. Schlager hypertensive mice exhibit a large variation in BP between the active and inactive periods of the day, and also show a morning surge in BP. To investigate the genes responsible for the circadian variation in BP in hypertension, hypothalamic tissue was collected from BPH/2J and normotensive BPN/3J mice at the ‘peak’ (n = 12) and ‘trough’ (n = 6) of diurnal BP. Using Affymetrix GeneChip® Mouse Gene 1.0 ST Arrays, validation by quantitative real-time PCR and a statistical method that adjusted for clock genes, we identified 212 hypothalamic genes whose expression differed between ‘peak’ and ‘trough’ BP in the hypertensive strain. These included genes with known roles in BP regulation, such as vasopressin, oxytocin and thyrotropin releasing hormone, as well as genes not recognized previously as regulators of BP, including chemokine (C-C motif) ligand 19, hypocretin and zinc finger and BTB domain containing 16. Gene ontology analysis showed an enrichment of terms for inflammatory response, mitochondrial proton-transporting ATP synthase complex, structural constituent of ribosome, amongst others. In conclusion, we have identified genes whose expression differs between the peak and trough of 24-hour circadian BP in BPH/2J mice, pointing to mechanisms responsible for diurnal variation in BP. The findings may assist in the elucidation of the mechanism for the morning surge in BP in essential hypertension

Amplification efficiency: linking baseline and bias in the analysis of quantitative PCR data

Despite the central role of quantitative PCR (qPCR) in the quantification of mRNA transcripts, most analyses of qPCR data are still delegated to the software that comes with the qPCR apparatus. This is especially true for the handling of the fluorescence baseline. This article shows that baseline estimation errors are directly reflected in the observed PCR efficiency values and are thus propagated exponentially in the estimated starting concentrations as well as ‘fold-difference’ results. Because of the unknown origin and kinetics of the baseline fluorescence, the fluorescence values monitored in the initial cycles of the PCR reaction cannot be used to estimate a useful baseline value. An algorithm that estimates the baseline by reconstructing the log-linear phase downward from the early plateau phase of the PCR reaction was developed and shown to lead to very reproducible PCR efficiency values. PCR efficiency values were determined per sample by fitting a regression line to a subset of data points in the log-linear phase. The variability, as well as the bias, in qPCR results was significantly reduced when the mean of these PCR efficiencies per amplicon was used in the calculation of an estimate of the starting concentration per sample

Involvement of (pro)renin receptor in the glomerular filtration barrier

(Pro)renin receptor-bound prorenin not only causes the generation of angiotensin II via the nonproteolytic activation of prorenin, it also activates the receptor’s own intracellular signaling pathways independent of the generated angiotensin II. Within the kidneys, the (pro)renin receptor is not only present in the glomerular mesangium, it is also abundant in podocytes, which play an important role in the maintenance of the glomerular filtration barrier. Recent in vivo studies have demonstrated that the overexpression of the (pro)renin receptor to a degree similar to that observed in hypertensive rat kidneys leads to slowly progressive nephropathy with proteinuria. In addition, the handle region peptide, which acts as a decoy peptide and competitively inhibits the binding of prorenin to the receptor, is more beneficial than an angiotensin-converting enzyme inhibitor with regard to alleviating proteinuria and glomerulosclerosis in experimental animal models of diabetes and essential hypertension. Thus, the (pro)renin receptor may be upregulated in podocytes under hypertensive conditions and may contribute to the breakdown of the glomerular filtration barrier