Gaussian processes and SVM: Mean field results and leave-one-out

In this chapter, we elaborate on the well-known relationship between Gaussian processes (GP) and Support Vector Machines (SVM). Secondly, we present approximate solutions for two computational problems arising in GP and SVM. The first one is the calculation of the posterior mean for GP classifiers using a `naive' mean field approach. The second one is a leave-one-out estimator for the generalization error of SVM based on a linear response method. Simulation results on a benchmark dataset show similar performances for the GP mean field algorithm and the SVM algorithm. The approximate leave-one-out estimator is found to be in very good agreement with the exact leave-one-out error.

Directing under disqualification:leave to act

Reviews the procedures by which a disqualified director can continue to act. Views this siutation through two recent cases. Highlights that courts should not fetter the Company Directors Disqualification Act 1986, s 17 discretion and reject the approach of earlier cases that in order for leave to be granted, a need on the part of the director or company was a prerequisite.

Antimicrobial efficacy of chlorhexidine digluconate alone and in combination with eucalyptus oil, tea tree oil and thymol against planktonic and biofilm cultures of Staphylococcus epidermidis

Objectives Effective skin antisepsis and disinfection of medical devices are key factors in preventing many healthcare-acquired infections associated with skin microorganisms, particularly Staphylococcus epidermidis. The aim of this study was to investigate the antimicrobial efficacy of chlorhexidine digluconate (CHG), a widely used antiseptic in clinical practice, alone and in combination with tea tree oil (TTO), eucalyptus oil (EO) and thymol against planktonic and biofilm cultures of S. epidermidis. Methods Antimicrobial susceptibility assays against S. epidermidis in a suspension and in a biofilm mode of growth were performed with broth microdilution and ATP bioluminescence methods, respectively. Synergy of antimicrobial agents was evaluated with the chequerboard method. Results CHG exhibited antimicrobial activity against S. epidermidis in both suspension and biofilm (MIC 2–8 mg/L). Of the essential oils thymol exhibited the greatest antimicrobial efficacy (0.5–4 g/L) against S. epidermidis in suspension and biofilm followed by TTO (2–16 g/L) and EO (4–64 g/L). MICs of CHG and EO were reduced against S. epidermidis biofilm when in combination (MIC of 8 reduced to 0.25–1 mg/L and MIC of 32–64 reduced to 4 g/L for CHG and EO, respectively). Furthermore, the combination of EO with CHG demonstrated synergistic activity against S. epidermidis biofilm with a fractional inhibitory concentration index of <0.5. Conclusions The results from this study suggest that there may be a role for essential oils, in particular EO, for improved skin antisepsis when combined with CHG.

In vitro activities of novel oxapenems, alone and in combination with ceftazidime, against gram-positive and gram-negative organisms

Four novel oxapenem compounds (i.e., AM-112, AM-113, AM-114, and AM-115) were investigated for their β-lactamase inhibitory activity against a panel of isolated class A, C, and D enzymes, which included expanded-spectrum β-lactamase enzymes (ESBLs). The oxapenems were potent β-lactamase inhibitors. Activity varied within the group, with AM-113 and AM-114 proving to be the most active compounds. The 50% inhibitory concentrations for these agents were up to 100,000-fold lower than that of clavulanic acid against class C and D enzymes. As a group, the oxapenems were more potent than clavulanic acid against enzymes from all classes. The ability of these compounds to protect ceftazidime from hydrolysis by β-lactamase-producing strains was evaluated by MIC tests that combined ceftazidime and each oxapenem in a 1:1 or 2:1 ratio. The oxapenems markedly reduced the MICs for ceftazidime against class C hyperproducing strains and strains producing TEM- and SHV-derived ESBLs. There was little difference between the activity of 1:1 and 2:1 combinations of ceftazidime and oxapenem. The oxapenems failed to enhance the activity of ceftazidime against derepressed AmpC-producing Pseudomonas aeruginosa strains.

Stand-alone groundwater desalination system using reverse osmosis combined with a cooled greenhouse for use in arid and semi-arid zones of India

In many areas of northern India, salinity renders groundwater unsuitable for drinking and even for irrigation. Though membrane treatment can be used to remove the salt, there are some drawbacks to this approach e.g. (1) depletion of the groundwater due to over-abstraction, (2) saline contamination of surface water and soil caused by concentrate disposal and (3) high electricity usage. To address these issues, a system is proposed in which a photovoltaic-powered reverse osmosis (RO) system is used to irrigate a greenhouse (GH) in a stand-alone arrangement. The concentrate from the RO is supplied to an evaporative cooling system, thus reducing the volume of the concentrate so that finally it can be evaporated in a pond to solid for safe disposal. Based on typical meteorological data for Delhi, calculations based on mass and energy balance are presented to assess the sizing and cost of the system. It is shown that solar radiation, freshwater output and evapotranspiration demand are readily matched due to the approximately linear relation among these variables. The demand for concentrate varies independently, however, thus favouring the use of a variable recovery arrangement. Though enough water may be harvested from the GH roof to provide year-round irrigation, this would require considerable storage. Some practical options for storage tanks are discussed. An alternative use of rainwater is in misting to reduce peak temperatures in the summer. An example optimised design provides internal temperatures below 30EC (monthly average daily maxima) for 8 months of the year and costs about €36,000 for the whole system with GH floor area of 1000 m2 . Further work is needed to assess technical risks relating to scale-deposition in the membrane and evaporative pads, and to develop a business model that will allow such a project to succeed in the Indian rural context.

The rise and fall of stand-alone social reporting in a multinational subsidiary in Bangladesh:a case study

Purpose -The main aim of this paper is to examine the underlying drivers for the development and subsequent discontinuation of stand-alone corporate social responsibility (CSR) reporting in a multinational subsidiary in Bangladesh. Design/Methodology/Approach - The research approach employed for this purpose is a case study using evidence from a series of in depth interviews conducted during the period 2002-2010. Interview data is supplemented by examining other sources of information including annual reports, stand-alone social reports and relevant newspaper articles during the study period. Findings - It appears that the stand-alone CSR reporting process was initiated to give the subsidiary a formal space in which to legitimise its activities in Bangladesh where both tobacco control regulation and a strong anti-tobacco movement were gaining momentum. At the start of the process in 2002 corporate interviewees were very receptive of this initiative and strongly believed that it would not be a one off exercise. However, in the face of subsequent significant national policy shifts concerning tobacco control, irreconcilable stakeholder demands and increasing criticism of the CSR activities of the organisation at home and abroad the process was brought to an abrupt end in 2009. Research Limitations/Implications - The paper has a number of implications for policy makers concerning the future prospects for stand-alone social/sustainability reporting as a means of enhancing organisational transparency and accountability. In addition the paper discusses a number of theoretical implications for the development of legitimacy theory. Originality/value - Using the lens of legitimacy the paper theorises the circumstances leading to the initiation and subsequent cessation of CSR reporting in the organisation concerned. As far as we know this is the first study which theorises and provides significant fieldwork based empirical evidence regarding the discontinuation of stand-alone social reporting by a multinational company operating in a developing country. Thus, it extends previous desk-based attempts at using legitimacy theory to explain a decrease (or discontinuity) in CSR disclosures by de Villiers and van Staden (2006) and Tilling and Tilt (2010).

The future of engineering - Do primary school engineering education interventions leave a lasting impression?

This positional paper proposes a conceptual framework and methodological approach for use in a PhD study investigating the longer term educational and social impact of 'active' engineering focused interventions for children age 8-10 in the UK. The study will critically analyse how a child's participation in an engineering education activity contributes to the Engineering Capital that the child possesses; focusing on how the child's awareness and perceptions about engineering are affected. To achieve this aim it is proposed that Grounded Theory methodology be used to enable an in-depth analysis of participation from the perspective of the child participant. The study proposed will be longitudinal, taking place over three formative years for the education and career aspirations of the child, from age 8-10 to 11-13. Although the research is in its infancy, this paper will provide the opportunity to develop theory in an underdeveloped area of engineering education research.

Three-port DC-DC converter for stand-alone photovoltaic systems

System efficiency and cost effectiveness are of critical importance for photovoltaic (PV) systems. This paper addresses the two issues by developing a novel three-port dc-dc converter for stand-alone PV systems, based on an improved Flyback-Forward topology. It provides a compact single-unit solution with a combined feature of optimized maximum power point tracking (MPPT), high step-up ratio, galvanic isolation, and multiple operating modes for domestic and aerospace applications. A theoretical analysis is conducted to analyze the operating modes followed by simulation and experimental work. This paper is focused on a comprehensive modulation strategy utilizing both PWM and phase-shifted control that satisfies the requirement of PV power systems to achieve MPPT and output voltage regulation. A 250-W converter was designed and prototyped to provide experimental verification in term of system integration and high conversion efficiency.

Going it alone? North Korea’s adaptability as a small power in a changing world

This article uses small states scholarship to map North Korea’s evolution from a post-colonial small state to a system-influencing state due to its nuclear weapons programme. The framework allows for contributions to: (1) The DPRK literature which in some parts has suggested the future collapse of the state, (2) The small states literature that suggests they can only survive if they integrate larger political and/or economic units, (3) The mainstream IR literature and its dominant realist streak that considers great powers and their will as the main drivers in contemporary world politics.