The Structure of High Strehl Ratio Point-Spread Functions

We describe the symmetries present in the point-spread function (PSF) of an optical system either located in space or corrected by an adaptive o to Strehl ratios of about 70% and higher. We present a formalism for expanding the PSF to arbitrary order in terms of powers of the Fourier transform of the residual phase error, over an arbitrarily shaped and apodized entrance aperture. For traditional unapodized apertures at high Strehl ratios, bright speckles pinned to the bright Airy rings are part of an antisymmetric perturbation of the perfect PSF, arising from the term that is first order in the residual phase error. There are two symmetric second degree terms. One is negative at the center, and, like the first order term, is modulated by the perfect image's field strength -- it reduces to the Marechal approximation at the center of the PSF. The other is non-negative everywhere, zero at the image center, and can be responsible for an extended halo -- which limits the dynamic range of faint companion detection in the darkest portions of the image. In regimes where one or the other term dominates the speckles in an image, the symmetry of the dominant term can be exploited to reduce the effect of those speckles, potentially by an order of magnitude or more. We demonstrate the effects of both secondary obscuration and pupil apodization on the structure of residual speckles, and discuss how these symmetries can be exploited by appropriate telescope and instrument design, observing strategies, and filter bandwidths to improve the dynamic range of high dynamic range AO and space-based observations. Finally, we show that our analysis is relevant to high dynamic range coronagraphy.Comment: Accepted for publication in ApJ; 20 pages, 4 figure

Chemoselective Suzuki-Miyaura cross-coupling via kinetic transmetallation

Chemoselective Suzuki-Miyaura cross-coupling generally requires a designed deactivation of one nucleophile towards transmetallation. Here we show that boronic acids can be chemoselectively reacted in the presence of ostensibly equivalently reactive boronic acid pinacol (BPin) esters by kinetic discrimination during transmetallation. Simultaneous electrophile control allows sequential chemoselective cross-couplings in a single operation in the absence of protecting groups

Most Recommended Choral Music: A Survey Of High School State Choral Festival Repertoire Lists

The purpose of this research study is to determine the most frequently listed choral selections on state choral festival repertoire lists and to survey state repertoire directors regarding their opinions of the most important literature for high school choral students. Five questions guided this research: What are the most frequently listed works on state repertoire lists? Which styles do repertoire directors indicate as most important for a vocal music education? Is there any relationship between the compilation of literature and the state repertoire directors’ opinions regarding the importance of specific styles? What is the process for adding works to state repertoire lists? What are the most important factors in determining what works are added to the state repertoire lists? The researcher provided a music list of the most recommended works. Additionally, listed musical styles appear in rank order by directors’ opinions of importance to the high school choral curriculum

Synthesis of oxindoles and benozfuranones via oxidation of 2-heterocyclic BMIDAs

The synthesis of functionalized oxindoles and benzofuranones via oxidation of 2-BMIDA indoles and benzofurans, respectively, is described. Interconversion of boron species (BMIDAàBF3K) was necessary to enable oxidation and overcome boronic acid stability issues associated with a difficult BMIDA hydrolysis. Overall, a robust process was developed that allowed access to a small library of oxindole and benzofuranone products and facilitated the step-efficient synthesis of biologically-active compounds containing the oxindole pharmacophore

Impacts of GSS on Moral Discourse: An Argumentation Analysis

Although ethical decision making is a key concern of organizations, the impacts of IT on ethical discourse is an underexplored topic. The laboratory experiment reported in this paper examines the impacts of the use of group support systems (GSSs) on moral discourse. Drawing upon Toulmin’s (1958) model of argumentation and Kohlberg’s (1976) framework of stages of moral reasoning, we used the technique of argumentation mapping (Fletcher and Huff 1990) to analyze group discussions of scenarios involving music piracy and hacktivism (computer hacking for a social cause) by GSS-supported and face-to-face groups. The results indicate that use of GSS can have a significant impact on the extent and diversity of the argumentation contributed during group discussion involving ethical dilemmas, including the number of grounds and rebuttals and the number of unique stages of moral reasoning underpinning the argumentation

Advances in precision medicine: tailoring individualised therapies

The traditional bench-to-bedside pipeline involves using model systems and patient samples to provide insights into pathways deregulated in cancer. This discovery reveals new biomarkers and therapeutic targets, ultimately stratifying patients and informing cohort-based treatment options. Precision medicine (molecular profiling of individual tumors combined with established clinical-pathological parameters) reveals, in real-time, individual patient's diagnostic and prognostic risk profile, informing tailored and tumor-specific treatment plans. Here we discuss advances in precision medicine presented at the Irish Association for Cancer Research Annual Meeting, highlighting examples where personalized medicine approaches have led to precision discovery in individual tumors, informing customized treatment programs

Expanding the application of cassava value chain technologies through UPoCA project

Root and Tuber . IITA TechnologiesCassava has long been expected to play a key role in rural economic growth in Africa, but are we there yet? Although research partnerships have produced elite cassava varieties with 50% more yielding potential and demonstrated technologies to boost processing and marketing of cassava, the sub-sector is constrained by low productivity and marketing dificulties. In DR Congo, Ghana, Malawi and Sierra Leone, for example, cassava value chain actors are yet to respond to 2007 estimated $59 million trade opportunities through substitution of imported wheat lour with locally produced high quality cassava lour. Industrial pull for cassava would also aggravate hunger and poverty if yields do not increase from current national averages of 5 to 19t/ha to more than 25t/ha expected of released varieties under low input agriculture. In 2008, USAID and IITA initiated the project “Unleashing the Power of Cassava in Response to Food Price Crisis (UPOCA) as a multi-country and inter-institutional partnership enabling cassava sub-sectors to realize their full potential in rural economies. UPoCA project covers DR Congo, Ghana, Malawi, Mozambique, Nigeria, Sierra Leone, and Tanzania. UPoCA project draws on prior research results to increase on-farm cassava productivity and value adding processing for markets. By end 2009, small holder beneiciaries associated with 55 partner organizations and 11 agricultural related irms established 306 community cassava stem multiplication sites and root production farms totalling 10,097ha with 58 improved varieties. Through experiential learning at 24 hands-on short-term courses, 345 men and 142 women learnt improved techniques in cassava production, processing, product development, and packaging/labelling and 8 technologies were introduced to rural communities. Seven other papers in this symposium, based on these evolving UPoCA achievements, show that a longer-term cassava research for development partnership platform of this nature will enable cassava sub-sectors to contribute signiicantly to rural economic growth in Africa

Ablation of Barrett's oesophagus: towards improved outcomes for oesophageal cancer?

This is the accepted version of the following article: Mayne, G. C., Bright, T., Hussey, D. J. and Watson, D. I. (2012), Ablation of Barrett's oesophagus: towards improved outcomes for oesophageal cancer?. ANZ Journal of Surgery, 82: 592–598, which has been published in final form at doi:10.1111/j.1445-2197.2012.06151.xBarrett's oesophagus is the major risk factor for oesophageal adenocarcinoma. The management of Barrett’s oesophagus entails treating reflux symptoms with acid-suppressing medication or surgery (fundoplication). However neither form of anti-reflux therapy produces predictable regression, or prevents cancer development. Patients with Barrett’s oesophagus usually undergo endoscopic surveillance which aims to identify dysplastic changes or cancer at its earliest stage, when treatment outcomes should be better. Alternative endoscopic interventions are now available and are suggested for the treatment of early cancer, and prevention of progression of Barrett’s oesophagus to cancer. Such treatments could minimize the risks associated with oesophagectomy. The current status of these interventions is reviewed. Various endoscopic interventions have been described, but with long term outcomes uncertain, they remain somewhat controversial. Radiofrequency ablation (RFA) of dysplastic Barrett’s oesophagus might reduce the risk of cancer progression, although cancer development has been reported after this treatment. Endoscopic mucosal resection (EMR) allows a 1.5 to 2 cm diameter piece of oesophageal mucosa to be removed. This provides better pathology for diagnosis and staging, and if the lesion is confined to the mucosa and fully excised, EMR can be curative. The combination of EMR and RFA has been used for multifocal lesions, but long term outcomes are unknown. The new endoscopic interventions for Barrett’s oesophagus and early oesophageal cancer have potential to improve clinical outcomes, although evidence which confirms superiority over oesphagectomy is limited. Longer term outcome data and data from larger cohorts is required to confirm the appropriateness of these procedure

Using conditional kernel density estimation for wind power density forecasting

Of the various renewable energy resources, wind power is widely recognized as one of the most promising. The management of wind farms and electricity systems can benefit greatly from the availability of estimates of the probability distribution of wind power generation. However, most research has focused on point forecasting of wind power. In this paper, we develop an approach to producing density forecasts for the wind power generated at individual wind farms. Our interest is in intraday data and prediction from 1 to 72 hours ahead. We model wind power in terms of wind speed and wind direction. In this framework, there are two key uncertainties. First, there is the inherent uncertainty in wind speed and direction, and we model this using a bivariate VARMA-GARCH (vector autoregressive moving average-generalized autoregressive conditional heteroscedastic) model, with a Student t distribution, in the Cartesian space of wind speed and direction. Second, there is the stochastic nature of the relationship of wind power to wind speed (described by the power curve), and to wind direction. We model this using conditional kernel density (CKD) estimation, which enables a nonparametric modeling of the conditional density of wind power. Using Monte Carlo simulation of the VARMA-GARCH model and CKD estimation, density forecasts of wind speed and direction are converted to wind power density forecasts. Our work is novel in several respects: previous wind power studies have not modeled a stochastic power curve; to accommodate time evolution in the power curve, we incorporate a time decay factor within the CKD method; and the CKD method is conditional on a density, rather than a single value. The new approach is evaluated using datasets from four Greek wind farms