In-flight measurement of ice growth on an airfoil using an array of ultrasonic transducers

Results of preliminary tests to measure ice growth on an airfoil during flight icing conditions are presented. Ultrasonic pulse echo measurements of ice thickness are obtained from an array of eight ultrasonic transducers mounted flush with the leading edge of the airfoil. These thickness measurements are used to document the evolution of the ice shape during the encounter in the form of successive ice profiles. Results from 3 research flights are presented and discussed. The accuracy of the ultrasonic measurements is found to be within 0.5 mm of mechanical and stereo photograph measurements of the ice accretion

Method and apparatus for determining time, direction, and composition of impacting space particles

A space particle collector for recording the time specific particles are captured, and its direction at the time of capture, utilizes an array of targets, each comprised of an MOS capacitor on a chip charged from an external source and discharged upon impact by a particle through a tab on the chip that serves as a fuse. Any impacting particle creates a crater, but only the first will cause a discharge of the capacitor. A substantial part of the metal film around the first crater is burned off by the discharge current. The time of the impulse which burns the tab, and the identification of the target, is recorded together with data from flight instruments. The metal film is partitioned into pie sections to provide a plurality of targets on each of an array of silicon wafers, thus increasing the total number of identified particles that can be collected. It is thus certain which particles were captured at what specific times

Migration of Interplanetary Dust

We numerically investigate the migration of dust particles with initial orbits close to those of the numbered asteroids, observed trans-Neptunian objects, and Comet Encke. The fraction of silicate asteroidal particles that collided with the Earth during their lifetime varied from 1.1% for 100 micron particles to 0.008% for 1 micron particles. Almost all asteroidal particles with diameter d>4 microns collided with the Sun. The peaks in the migrating asteroidal dust particles' semi-major axis distribution at the n:(n+1) resonances with Earth and Venus and the gaps associated with the 1:1 resonances with these planets are more pronounced for larger particles. The probability of collisions of cometary particles with the Earth is smaller than for asteroidal particles, and this difference is greater for larger particles.Comment: Annals of the New York Academy of Sciences, 15 pages, 8 Figures, submitte

Generalized line criterion for Gauss-Seidel method

We present a module based criterion, i.e. a sufficient condition based on the absolute value of the matrix coefficients, for the convergence of Gauss-Seidel method (GSM) for a square system of linear algebraic equations, the Generalized Line Criterion (GLC). We prove GLC to be the ''most general'' module based criterion and derive, as GLC corollaries, some previously know and also some new criteria for GSM convergence. Although far more general than the previously known results, the proof of GLC is simpler. The results used here are related to recent research in stability of dynamical systems and control of manufacturing systems

A service evaluation of FIT and anaemia for risk stratification in the two week wait pathway for colorectal cancer

Introduction: New national guidance on urgent referral for investigation for Colorectal Cancer (CRC) included faecal occult blood testing in 2015. We evaluated faecal immunochemical testing (FIT) and anaemia as risk stratification tools in symptomatic patients suspected of having CRC.Methods: Postal FIT was incorporated into the CRC two week wait (2WW) pathway for all patients without rectal bleeding in 2016. Patients were investigated in the 2WW pathway as normal and outcomes of investigations were prospectively recorded. Anaemia was defined as haemoglobin less than 120g/L in women and less than 130g/L in men.Results: FIT kits were sent to 1106 patients with an 80.9% return rate; 810 patients completed investigation with 40 CRCs diagnosed (4.9%). Median FIT results were significantly higher in patients who were anaemic (median 4.8 iqr 0.8-34.1 versus 1.2 iqr 0-6.4, Mann-Whitney p less than 0.001).Some 538 (60.4%) had a result of less than 4 µgHb/gFaeces (limit of detectability) and 621 (69.7%) a result less than 10 µgHb/gFaeces. Sixty per cent of CRCs had a FIT reading of >150 µgHb/gFaeces. Five CRCs diagnosed in patients with a FIT4 µgHb/gFaeces had 97.5% sensitivity and 64.5% specificity for CRC diagnosis. A FIT result of >4 µgHb/gFaeces and/or anaemia had a 100% sensitivity and 45.3% specificity for CRC diagnosis.Conclusion: FIT is most useful at the extremes of detectability; strongly positive readings predict high rates of CRC and other significant pathology, whilst very low readings in the absence of anaemia or palpable rectal mass identify a group with very low risk. High return rates for FIT within this 2WW pathway indicate its acceptability

A feature selection approach for identification of signature genes from SAGE data

<p>Abstract</p> <p>Background</p> <p>One goal of gene expression profiling is to identify signature genes that robustly distinguish different types or grades of tumors. Several tumor classifiers based on expression profiling have been proposed using microarray technique. Due to important differences in the probabilistic models of microarray and SAGE technologies, it is important to develop suitable techniques to select specific genes from SAGE measurements.</p> <p>Results</p> <p>A new framework to select specific genes that distinguish different biological states based on the analysis of SAGE data is proposed. The new framework applies the bolstered error for the identification of strong genes that separate the biological states in a feature space defined by the gene expression of a training set. Credibility intervals defined from a probabilistic model of SAGE measurements are used to identify the genes that distinguish the different states with more reliability among all gene groups selected by the strong genes method. A score taking into account the credibility and the bolstered error values in order to rank the groups of considered genes is proposed. Results obtained using SAGE data from gliomas are presented, thus corroborating the introduced methodology.</p> <p>Conclusion</p> <p>The model representing counting data, such as SAGE, provides additional statistical information that allows a more robust analysis. The additional statistical information provided by the probabilistic model is incorporated in the methodology described in the paper. The introduced method is suitable to identify signature genes that lead to a good separation of the biological states using SAGE and may be adapted for other counting methods such as Massive Parallel Signature Sequencing (MPSS) or the recent Sequencing-By-Synthesis (SBS) technique. Some of such genes identified by the proposed method may be useful to generate classifiers.</p

Challenging the 'New Professionalism': from managerialism to pedagogy?

In recent years there have been changes made to the conceptualisation of continuing professional development for teachers in both the Scottish and English systems of education. These changes have been instigated by successive UK governments (and more recently, by the Scottish Executive), together with the General teaching Council for Scotland (GTCS) and the General Teaching Council for England (GTCE). This paper argues that these changes have not provided a clear rationale for CPD, but instead have introduced tensions between the concept of teacher education and that of training. The need for a less confused understanding of CPD and its purposes is underlined, as is the need for school based approaches to continuing teacher education. Arguably, teacher education must move from technicist emphases to a model which integrates the social processes of change within society and schools with the individual development and empowerment of teachers

Life-Expectancy Disparities Among Adults With HIV in the United States and Canada: The Impact of a Reduction in Drug- and Alcohol-Related Deaths Using the Lives Saved Simulation Model.

Improvements in life expectancy among people living with human immunodeficiency virus (PLWH) receiving antiretroviral treatment in the United States and Canada might differ among key populations. Given the difference in substance use among key populations and the current opioid epidemic, drug- and alcohol-related deaths might be contributing to the disparities in life expectancy. We sought to estimate life expectancy at age 20 years in key populations (and their comparison groups) in 3 time periods (2004-2007, 2008-2011, and 2012-2015) and the potential increase in expected life expectancy with a simulated 20% reduction in drug- and alcohol-related deaths using the novel Lives Saved Simulation model. Among 92,289 PLWH, life expectancy increased in all key populations and comparison groups from 2004-2007 to 2012-2015. Disparities in survival of approximately a decade persisted among black versus white men who have sex with men and people with (vs. without) a history of injection drug use. A 20% reduction in drug- and alcohol-related mortality would have the greatest life-expectancy benefit for black men who have sex with men, white women, and people with a history of injection drug use. Our findings suggest that preventing drug- and alcohol-related deaths among PLWH could narrow disparities in life expectancy among some key populations, but other causes of death must be addressed to further narrow the disparities