Cost-effective HPC clustering for computer vision applications

We will present a cost-effective and flexible realization of high performance computing (HPC) clustering and its potential in solving computationally intensive problems in computer vision. The featured software foundation to support the parallel programming is the GNU parallel Knoppix package with message passing interface (MPI) based Octave, Python and C interface capabilities. The implementation is especially of interest in applications where the main objective is to reuse the existing hardware infrastructure and to maintain the overall budget cost. We will present the benchmark results and compare and contrast the performances of Octave and MATLAB

The El Niño - Southern Oscillation, rainfall and wheat yields in South Africa

This thesis assesses the relationships between the El Niño-Southern Oscillation (ENSO), rainfall and South African commercial winter wheat yields from 1974 - 2000. The analysis is through a combination of the Pearson's product moment correlation coefficient and an assessment of the magnitude and consistency of rainfall and wheat anomalies in the year of, and the year following warm (El Niño) and cold (La Niña) ENSO events. The ENSO - rainfall relationship is analysed on timescales from 1 - 24 months and this study finds that there are more unusually dry and unusually wet months during El Niño events than during La Niña episodes (where dry and wet months are <75°/o and over 25~·'0 more than the 1921 - 2000 mean, respectively) and these conditions are consistently found in some rainfall areas during each El Niño or La Niño event; there is marked inter - El Niño and inter La Niña variation in late summer and annual rainfall; and that there has been a significant shift in the timings of maximum rainfall anomalies during El Niño episodes from an earlier investigation. The effects of rainfall on the wheat yield vary spatially, but are most apparent in the Free State where severe droughts have resulted in reduced yields. In the Northern Cape and Western Cape anomalously wet conditions, especially in late summer, coincide with reduced wheat yields. The ENSO - wheat yield relationship is not a simple linear one, and despite yields in the Northern Cape and Western Cape tracking Pacific sea surface temperatures by nearly a year, El Niño and La Niña years are not synonymous With increased or decreased yields in any province. ln fact, maximum and minimum yields in the Free State and Northern Cape are found in the year of, or year following a La Niño event, and consequently the present predictability of wheat yields by ENSO is limited. The relationships between ENSO, rainfall and wheat yield in South Africa is not readily apparent, which may be due to the short (<30 years) data set or mediating factors outside this study such as farm - management strategies or hemispheric variation in the evolution of El Niño and La Niña events

The Synthesis of 2, 11-Dithiabenzo - [3.3] - Paracyclophane and an Octadeutero Derivative

The purpose of this work was the synthesis of 2, 11 -dithia-benzo- [3.3] -paracyclophane and its octadeutero derivative 2,11-dithia- 3,3, 5, 6, 8, 9, 10, 10-octa­deutero-benzo - [3.3] paracyclophane. A comparison of their nuclear magnetic resonance spectra as well as their mass spectra will unequivocably provide proof of their successful synthesis

Values and Leadership: Theory Development, New Research, and an Agenda for the Future

This article presents an updated account of values and valuation processes as they occur in school settings. A tradition of epistemological and philosophical debate, as well as the dominance of empiricist perspectives in educational administration, have tended to separate the consideration of values as influences on leadership practices from the usual organizational or social collective perspectives common to the field. More recently, however, powerful social forces such as globalization and the increasing diversity of our societies have stimulated increased academic productivity in this sector. A more balanced view of values as an influence on administration is emerging, which combines notions of the personal values manifested by individuals and the professional values of administration with the collective values manifested by groups, societies, and organizations. Discussion and inquiry have now extended beyond the usual expert opinion and academic debate of theorists and philosophers to include practitioners, empirical verifications of theory, and important new research findings. In this article key concepts from theory and a selection of findings from research are reviewed. The application of theory and research about values through reflective educational practice is discussed. Certain methodological problems associated with values research are examined, and the ground breaking work of several key contributors to the field is identified and considered. The article concludes with some speculations on an agenda for future theory-building and research in the values field.Cet article présente une mise à jour des valeurs et du processus d'évaluation tels qu'ils se manifestent dans les milieux scolaires. Une tradition de débats épistémologiques et philosophiques, conjuguée à la dominance de perspectives empiristes en administration pédagogique, a fait en sorte que l'on a eu tendance à écarter l'interprétation des valeurs selon laquelle celles-ci agissent comme influences sur les pratiques administratives des perspectives collectives organisationnelles ou sociales couramment associées au domaine. Plus récemment par contre, des forces sociales puissantes telles la globalisation et la diversité croissante de nos sociétés ont stimulé une production académique accrue dans ce secteur. Défait, une vision plus équilibrée des valeurs comme facteurs ayant une influence sur l'administration commence à se faire sentir. Cette vision combine les valeurs personnelles qu'affichent les individus, les valeurs professionnelles d'une administration ainsi que les valeurs collectives manifestées par les groupes, les sociétés et les organisations. Les discussions et les enquêtes menées par les opinions d'experts et les débats académiques de théoriciens et philosophes englobent maintenant également les avis de praticiens, des vérifications empiriques de la théorie ainsi que d'importants nouveaux résultats de recherche. L'article passe en revue des concepts théoriques clés et une sélection de résultats de recherche. On y discute également l'application de la théorie et de la recherche portant sur les valeurs à la pratique pédagogique réfléchie. Suivent un examen de certains problèmes méthodologiques associés à la recherche sur les valeurs et une étude du travail révolutionnaire de plusieurs chercheurs clés du domaine. Des hypothèses quant à l'agenda qui guiderait la création de théories et l'orientation de la recherche sur les valeurs terminent l'article

Bioengineered Nisin A Derivatives with Enhanced Activity against Both Gram Positive and Gram Negative Pathogens

peer-reviewedNisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G), with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E) with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria.This work was supported by the Irish Government under the National Development Plan, through Science Foundation Ireland Investigator awards (10/IN.1/B3027) and (06/IN.1/B98) (http://www.sfi.ie)

Potential Use of Biotherapeutic Bacteria to Target Colorectal Cancer-Associated Taxa

peer-reviewedThe role of the gut microbiome in human health and disease is the focus of much attention. It has been widely agreed upon that our gut bacteria play a role in host immunity, nutrient absorption, digestion, metabolism, and other key drivers of health. Furthermore, certain microbial signatures and specific taxa have also been associated with the development of diseases, such as obesity; inflammatory bowel disease; and, indeed, colorectal cancer (CRC), which is the focus of this review. By extension, such taxa represent potential therapeutic targets. In particular, the emerging human pathogen Fusobacterium nucleatum represents an important agent in CRC development and its control within the gastrointestinal tract is desirable. This paper reviews the principal bacterial pathogens that have been associated with CRC to date and discusses the in vitro and human studies that have shown the potential use of biotherapeutic strains as a means of targeting CRC-associated bacteria

Identification and characterisation of capidermicin, a novel bacteriocin produced by Staphylococcus capitis

peer-reviewedOne hundred human-derived coagulase negative staphylococci (CoNS) were screened for antimicrobial activity using agar-based deferred antagonism assays with a range of indicator bacteria. Based on the findings of the screen and subsequent well assays with cell free supernatants and whole cell extracts, one strain, designated CIT060, was selected for further investigation. It was identified as Staphylococcus capitis and herein we describe the purification and characterisation of the novel bacteriocin that the strain produces. This bacteriocin which we have named capidermicin was extracted from the cell-free supernatant of S. capitis CIT060 and purified to homogeneity using reversed-phase high performance liquid chromatography (RP-HPLC). Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometric (MS) analysis revealed that the capidermicin peptide has a mass of 5,464 Da. Minimal inhibitory concentration (MIC) experiments showed that capidermicin was active in the micro-molar range against all the Gram-positive bacteria that were tested. Antimicrobial activity was retained over a range of pHs (2–11) and temperatures (10–121°C x 15 mins). The draft genome sequence of S. capitis CIT060 was determined and the genes predicted to be involved in the biosynthesis of capidermicin were identified. These genes included the predicted capidermicin precursor gene, and genes that are predicted to encode a membrane transporter, an immunity protein and a transcriptional regulator. Homology searches suggest that capidermicin is a novel member of the family of class II leaderless bacteriocins

Dopamine D_2-receptor activation elicits akinesia, rigidity, catalepsy, and tremor in mice expressing hypersensitive 4 nicotinic receptors via a cholinergic-dependent mechanism

Recent studies suggest that high-affinity neuronal nicotinic acetylcholine receptors (nAChRs) containing α4 and β2 subunits (α4β2*) functionally interact with G-protein-coupled dopamine (DA) D_2 receptors in basal ganglia. We hypothesized that if a functional interaction between these receptors exists, then mice expressing an M2 point mutation (Leu9'Ala) rendering 4 nAChRs hypersensitive to ACh may exhibit altered sensitivity to a D_2-receptor agonist. When challenged with the D_(2)R agonist, quinpirole (0.5–10 mg/kg), Leu9'Ala mice, but not wild-type (WT) littermates, developed severe, reversible motor impairment characterized by rigidity, catalepsy, akinesia, and tremor. While striatal DA tissue content, baseline release, and quinpirole-induced DA depletion did not differ between Leu9'Ala and WT mice, quinpirole dramatically increased activity of cholinergic striatal interneurons only in mutant animals, as measured by increased c-Fos expression in choline acetyltransferase (ChAT)-positive interneurons. Highlighting the importance of the cholinergic system in this mouse model, inhibiting the effects of ACh by blocking muscarinic receptors, or by selectively activating hypersensitive nAChRs with nicotine, rescued motor symptoms. This novel mouse model mimics the imbalance between striatal DA/ACh function associated with severe motor impairment in disorders such as Parkinson’s disease, and the data suggest that a D_(2)R–α4*-nAChR functional interaction regulates cholinergic interneuron activity.—Zhao-Shea, R., Cohen, B. N., Just, H., McClure-Begley, T., Whiteaker, P., Grady, S. R., Salminen, O., Gardner, P. D., Lester, H. A., Tapper, A. R. Dopamine D2-receptor activation elicits akinesia, rigidity, catalepsy, and tremor in mice expressing hypersensitive α4 nicotinic receptors via a cholinergic-dependent mechanism