High-Efficiency Harmonic-Peaking Class-EF Power Amplifiers with Enhanced Maximum Operating Frequency

The recently introduced Class-EF power amplifier (PA) has a peak switch voltage lower than that of the Class-E PA. However, the value of the transistor output capacitance at high frequencies is typically larger than the required Class-EF optimum shunt capacitance. Consequently, soft-switching operation that minimizes power dissipation during off-to-on transition cannot be achieved at high frequencies. Two new Class-EF PA variants with transmission-line load networks, namely, third-harmonic-peaking (THP) and fifth-harmonic-peaking (FHP) Class-EF PAs are proposed in this paper. These permit operation at higher frequencies at no expense to other PA figures of merit. Analytical expressions are derived in order to obtain circuit component values, which satisfy the required Class-EF impedances at fundamental frequency, all even harmonics, and the first few odd harmonics as well as simultaneously providing impedance matching to a 50- Ω load. Furthermore, a novel open-circuit and shorted stub arrangement, which has substantial practical benefits, is proposed to replace the normal quarter-wave line connected at the transistor's drain. Using GaN HEMTs, two PA prototypes were built. Measured peak drain efficiency of 91% and output power of 39.5 dBm were obtained at 2.22 GHz for the THP Class-EF PA. The FHP Class-EF PA delivered output power of 41.9 dBm with 85% drain efficiency at 1.52 GHz.

Institutional maintenance work and power preservation in business exchanges: Insights from industrial supplier workshops

This paper aims to offer new theoretical and empirical insights into power dynamics in an industrial supplier workshop setting. Theoretically, it advances an institutional perspective on supplier workshops as an important venue in managing, preserving and instituting industrial market power. Based on a detailed ethnographic analysis of an industrial workshop setting, this article investigates the institutional maintenance work of Retail Co. in preserving the power dynamics of market dominance in business exchanges and market structures. Our findings revealed three previously unreported insights into the subtle, but nonetheless pervasive power from institutional maintenance work in an industrial workshop setting. First, the institutional workshop work comprised a cultural performance; constituting socialization practice through a performance game, the power of numbers in field comprehension and an award ceremony. Second, the institutional workshop work mobilized projective agency, stipulating, directing and appealing for the instituting of distinct market rules and collective identities. Finally, the institutional workshop work increases supplier docility and utility via the regulative technologies-of-the-self to enhance business planning, operations and market decision-making practice, without necessarily being seen to be disciplinarian.

A comparison of two informative SNP-based strategies for typing Pseudomonas aeruginosa isolates from patients with cystic fibrosis

BACKGROUND: Molecular typing is integral for identifying Pseudomonas aeruginosa strains that may be shared between patients with cystic fibrosis (CF). We conducted a side-by-side comparison of two P. aeruginosa genotyping methods utilising informative-single nucleotide polymorphism (SNP) methods; one targeting 10 P. aeruginosa SNPs and using real-time polymerase chain reaction technology (HRM10SNP) and the other targeting 20 SNPs and based on the Sequenom MassARRAY platform (iPLEX20SNP).

METHODS: An in-silico analysis of the 20 SNPs used for the iPLEX20SNP method was initially conducted using sequence type (ST) data on the P. aeruginosa PubMLST website. A total of 506 clinical isolates collected from patients attending 11 CF centres throughout Australia were then tested by both the HRM10SNP and iPLEX20SNP assays. Type-ability and discriminatory power of the methods, as well as their ability to identify commonly shared P. aeruginosa strains, were compared.

RESULTS: The in-silico analyses showed that the 1401 STs available on the PubMLST website could be divided into 927 different 20-SNP profiles (D-value = 0.999), and that most STs of national or international importance in CF could be distinguished either individually or as belonging to closely related single- or double-locus variant groups. When applied to the 506 clinical isolates, the iPLEX20SNP provided better discrimination over the HRM10SNP method with 147 different 20-SNP and 92 different 10-SNP profiles observed, respectively. For detecting the three most commonly shared Australian P. aeruginosa strains AUST-01, AUST-02 and AUST-06, the two methods were in agreement for 80/81 (98.8%), 48/49 (97.8%) and 11/12 (91.7%) isolates, respectively.

CONCLUSIONS: The iPLEX20SNP is a superior new method for broader SNP-based MLST-style investigations of P. aeruginosa. However, because of convenience and availability, the HRM10SNP method remains better suited for clinical microbiology laboratories that only utilise real-time PCR technology and where the main interest is detection of the most highly-prevalent P. aeruginosa CF strains within Australian clinics.

Development of a combined RT-PCR: NGS assay for microRNA biomarkers

The ability of miRNAs to act as diagnostic biomarkers could be expanded by availability of improved methodologies to detect and analyse these molecules. We have therefore developed an assay with the ability to selectively analyse pools of miRNAs, using the specificity of PCR to select targets and the power of NGS to reveal isomiRs of the chosen targets in a total assay time of two days.

Application of laser radiation for the treatment of waste materials using a photocatalyst

One effective approach is to destroy industrial waste and pollution is the use of a semiconductor photocatalysis system. To date such, photocatalysis systems have employed conventional linear light sources. Initial results from a study of a photocatalysis system incorporating a tripled Nd:YAG laser are reported. The laser light not only played a roll as a light source for activating the photocatalyst(TiO₂), but also destroyed the organic species directly via a photochemical process. The reaction intermediates and changes in their concentrations are monitored using HPLC. The relationship between the power of laser and kinetics of photoreaction are discussed.

Meta-analysis of the influence of experimental design on effect size in peer tutoring outcomes in elementary, middle and high school settings.

A meta-analysis was undertaken on a form of cooperative learning, peer tutoring. The effects of experimental design on outcomes were explored, as measured by Effect Size (ES). 185 studies were included in the meta-analysis. Highest ES were reported for quasi-experimental studies. ES reduced as experimental design moved from single pre-test factor matched, to multiple-factor matched randomized controlled trials. ES reduced when designs used standardised, rather than self-designed measures, The implications for future meta-analyses and research in cooperative learning are explored.

Genetics of Diabetic Nephropathy: a Long Road of Discovery

The global prevalence of diabetic nephropathy is rising in parallel with the increasing incidence of diabetes in most countries. Unfortunately, up to 40 % of persons diagnosed with diabetes may develop kidney complications. Diabetic nephropathy is associated with substantially increased risks of cardiovascular disease and premature mortality. An inherited susceptibility to diabetic nephropathy exists, and progress is being made unravelling the genetic basis for nephropathy thanks to international research collaborations, shared biological resources and new analytical approaches. Multiple epidemiological studies have highlighted the clinical heterogeneity of nephropathy and the need for better phenotyping to help define important subgroups for analysis and increase the power of genetic studies. Collaborative genome-wide association studies for nephropathy have reported unique genes, highlighted novel biological pathways and suggested new disease mechanisms, but progress towards clinically relevant risk prediction models for diabetic nephropathy has been slow. This review summarises the current status, recent developments and ongoing challenges elucidating the genetics of diabetic nephropathy.

Revolting Arts or Spatial Democracy: Performances of popular arts during the Egyptian Revolution?

This paper investigates how spatial practices of Public art performance had transformed public space from being a congested traffic hub into an active and animated space for resistance that was equally accessible to different factions, social strata, media outlets and urban society, determined by popular culture and social responsibility. Tahrir Square was reproduced, in a process of “space adaptation” using Henri Lefebvre’s term, to accommodate forms of social organization and administration.205 Among the spatial patterns of activities detected and analyzed this paper focus on particular forms of mass practices of art and freedom of expression that succeeded to transform Tahrir square into performative space and commemorate its spatial events. It attempts to interrogate how the power of artistic interventions has recalled socio-cultural memory through spatial forms that have negotiated middle grounds between deeply segregated political and social groups in moments of utopian democracy. Through analytical surveys and decoding of media recordings of the events, direct interviews with involved actors and witnesses, this paper offers insight into the ways protesters lent their artistry capacity to the performance of resistance to become an act of spatial festivity or commemoration of events. The paper presents series of analytical maps tracing how the role of art has shifted significantly from traditional freedom of expression modes as narrative of resistance into more sophisticated spatial performative ones that take on a new spatial vibrancy and purpose.

A comparison of merging operators in possibilistic logic.

In this paper, we compare merging operators in possibilistic logic. We rst propose an approach to evaluating the discriminating power of a merging operator. After that, we analyze the computational complexity of existing possibilistic merging operators. Finally, we consider the compatibility of possibilistic merging operators with propositional merging operators.

Top incomes under finance-driven capitalism, 1990-2010: power resources and regulatory orders

This article examines the impact of financialisation on the income shares of the top 1% from 1990-2010, through a panel analysis of 14 OECD countries. Drawing together literatures stressing the dependence of income inequality on the structural bargaining power of capital relative to labour, and of the dependence of accumulation on underlying institutionalised modes of state regulation, it shows that financialisation has significantly enhanced top income shares net of underlying controls. Whilst the income shares of the top 1% appear responsive to variables typical of wider studies of personal income inequality, we emphasise distinctive mechanisms of top income growth linked to the rising dominance of financial instruments and actors, facilitated by a historically specific regulatory order. These conditions were key to the emergence of a state of ‘asymmetric bargaining’ which disproportionately enhanced the fortunes of the wealthy. Results thus emphasise the importance of class-biased power resources and underlying regulatory structures, as determinants both of income concentration and of the distribution of economic rewards beyond growth capacity alone.

Giving structure to the biofilm matrix: an overview of individual strategies and emerging common themes

Biofilms are communities of microbial cells that underpin diverse processes including sewage bioremediation, plant growth promotion, chronic infections and industrial biofouling. The cells resident in the biofilm are encased within a self-produced exopolymeric matrix that commonly comprises lipids, proteins that frequently exhibit amyloid-like properties, eDNA and exopolysaccharides. This matrix fulfils a variety of functions for the community, from providing structural rigidity and protection from the external environment to controlling gene regulation and nutrient adsorption. Critical to the development of novel strategies to control biofilm infections, or the capability to capitalize on the power of biofilm formation for industrial and biotechnological uses, is an in-depth knowledge of the biofilm matrix. This is with respect to the structure of the individual components, the nature of the interactions between the molecules and the three-dimensional spatial organization. We highlight recent advances in the understanding of the structural and functional role that carbohydrates and proteins play within the biofilm matrix to provide three-dimensional architectural integrity and functionality to the biofilm community. We highlight, where relevant, experimental techniques that are allowing the boundaries of our understanding of the biofilm matrix to be extended using Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis as exemplars.

The implausibility of ‘usual care’ in an open system: sedation and weaning practices in Paediatric Intensive Care Units (PICUs) in the United Kingdom (UK).

Background
The power of the randomised controlled trial depends upon its capacity to operate in a closed system whereby the intervention is the only causal force acting upon the experimental group and absent in the control group, permitting a valid assessment of intervention efficacy. Conversely, clinical arenas are open systems where factors relating to context, resources, interpretation and actions of individuals will affect implementation and effectiveness of interventions. Consequently, the comparator (usual care) can be difficult to define and variable in multi-centre trials. Hence outcomes cannot be understood without considering usual care and factors that may affect implementation and impact on the intervention.

Methods
Using a fieldwork approach, we describe PICU context, ‘usual’ practice in sedation and weaning from mechanical ventilation, and factors affecting implementation prior to designing a trial involving a sedation and ventilation weaning intervention. We collected data from 23 UK PICUs between June and November 2014 using observation, individual and multi-disciplinary group interviews with staff.

Results
Pain and sedation practices were broadly similar in terms of drug usage and assessment tools. Sedation protocols linking assessment to appropriate titration of sedatives and sedation holds were rarely used (9 % and 4 % of PICUs respectively). Ventilator weaning was primarily a medical-led process with 39 % of PICUs engaging senior nurses in the process: weaning protocols were rarely used (9 % of PICUs). Weaning methods were variably based on clinician preference. No formal criteria or use of spontaneous breathing trials were used to test weaning readiness. Seventeen PICUs (74 %) had prior engagement in multi-centre trials, but limited research nurse availability. Barriers to previous trial implementation were intervention complexity, lack of belief in the evidence and inadequate training. Facilitating factors were senior staff buy-in and dedicated research nurse provision.

Conclusions
We examined and identified contextual and organisational factors that may impact on the implementation of our intervention. We found usual practice relating to sedation, analgesia and ventilator weaning broadly similar, yet distinctively different from our proposed intervention, providing assurance in our ability to evaluate intervention effects. The data will enable us to develop an implementation plan; considering these factors we can more fully understand their impact on study outcomes.