The junior South African individual scale as predictor of scholastic achievement at Sub A, Sub B & Std One levels

This study examines the relationship between the eight subtest form of the Junior South African Individual Scale (JSAIS - 8) and scholastic performance at Sub A, Sub B and Std One levels, as measured by teacher evaluations. An unreferred sample of 104 pupils who had been tested on the JSAIS- 8 in their Sub A year were followed up at the end of Std One. The pupils' three sets of year-end symbols, as recorded in the official school records, were obtained. Pearson correlations were calculated between the Global, Verbal Performance and Numerical Scales and each of the subtests on the one hand, and selected school subjects and a computed average of the subjects on the other. The JSAIS scales and subtests were regressed on the computed averages for each standard. A test was performed to evaluate the longitudinal stability of the correlation matrix of Pearson correlations. The results were compared with those of similar studies employing non-South African intelligence scales, and with a study employing the full, twelve subtest version of the JSAIS (JSAIS - 12). The values of the correlations yielded were found to be of the same general magnitude as those reported in studies employing non-South African scales. The test for the longitudinal stability of the Pearson correlation matrix indicated that the test probably predicted equally over the three standard levels. The Global, Verbal and Numerical Scales and their associated subtests correlated moderately to highly with measures of scholastic achievement. The Performance Scale and its subtests yielded lower and sometimes non-significant correlations. Some discrepancies were noted between the results of the present study and that which employed the JSAIS - 12. It was observed that three of the five subtests which yielded the highest correlations with scholastic achievement in the study employing the JSAIS - 12 are excluded from the JSAIS - 8. The possibility of substituting these subtests for three subtests currently incorporated in the JSAIS - 8 was explored. Limitations of the present study were discussed and the tentative nature of the findings emphasised. Suggestions were made for further research

The Wide-field High-resolution Infrared TElescope (WHITE)

The Wide-field High-resolution Infrared TElescope (WHITE) will be dedicated in the first years of its life to carrying out a few (well focused in terms of science objectives and time) legacy surveys. WHITE would have an angular resolution of ~0.3'' homogeneous over ~0.7 sq. deg. in the wavelength range 1 - 5 um, which means that we will very efficiently use all the available observational time during night time and day time. Moreover, the deepest observations will be performed by summing up shorter individual frames. We will have a temporal information that can be used to study variable objects. The three key science objectives of WHITE are : 1) A complete survey of the Magellanic Clouds to make a complete census of young stellar objects in the clouds and in the bridge and to study their star formation history and the link with the Milky Way. The interaction of the two clouds with our Galaxy might the closest example of a minor merging event that could be the main driver of galaxy evolution in the last 5 Gyrs. 2) The building of the first sample of dusty supernovae at z<1.2 in the near infrared range (1-5 um) to constrain the equation of state from these obscured objects, study the formation of dust in galaxies and build the first high resolution sample of high redshift galaxies observed in their optical frame 3) A very wide weak lensing survey over that would allow to estimate the equation of state in a way that would favourably compete with space projects.Comment: Invited talk to the 2nd ARENA Conference : "The Astrophysical Science Cases at Dome C" Potsdam 17-21 September, 200

Block Coordinate Descent for Sparse NMF

Nonnegative matrix factorization (NMF) has become a ubiquitous tool for data analysis. An important variant is the sparse NMF problem which arises when we explicitly require the learnt features to be sparse. A natural measure of sparsity is the L$_0$ norm, however its optimization is NP-hard. Mixed norms, such as L$_1$/L$_2$ measure, have been shown to model sparsity robustly, based on intuitive attributes that such measures need to satisfy. This is in contrast to computationally cheaper alternatives such as the plain L$_1$ norm. However, present algorithms designed for optimizing the mixed norm L$_1$/L$_2$ are slow and other formulations for sparse NMF have been proposed such as those based on L$_1$ and L$_0$ norms. Our proposed algorithm allows us to solve the mixed norm sparsity constraints while not sacrificing computation time. We present experimental evidence on real-world datasets that shows our new algorithm performs an order of magnitude faster compared to the current state-of-the-art solvers optimizing the mixed norm and is suitable for large-scale datasets

Numerical model validation for mooring systems: Method and application for wave energy converters

PublishedArticleMooring systems are key sub-systems of wave energy devices. The design of mooring systems is challenging because overdesign of the mooring system incurs a significant cost penalty, while underdesign may lead to a premature failure. Incorrect design could also reduce the power production. It is therefore important to develop mooring systems which are specific for wave energy applications. In particular, very compliant mooring systems which allow the system to be highly dynamic are being developed. The validation of numerical models with data from physical experiments would facilitate the development of appropriate mooring solutions. This paper presents tank test results for a scale model of the buoy and mooring used at the South West Mooring Test Facility (SWMTF), an offshore facility developed to conduct long-term sea trials for wave energy device moorings. The mooring system investigated is a compliant 3 leg catenary mooring system using Nylon ropes in the water column. Preliminary static, quasi-static, decay, regular and irregular wave tests were conducted on the 1:5 scale model, using the Ifremer basin in Brest. A corresponding numerical model was developed with a time-domain mooring modelling tool, inputting hydrodynamic data from a radiation/diffraction potential modelling program. After the calibration of several hydrodynamic parameters (added mass, damping and mean drift), the numerical model demonstrated good agreement with the experiment, providing an accurate prediction of the maximum mooring loads in irregular waves. However, results show large differences with the field test results, mainly because of the anchor position. The methods and procedures presented will allow the effective validation of numerical models to enable the development of appropriate mooring systems in wave energy applications.The authors acknowledge the support of the MERiFIC (4122) project partners (Marine Energy in Far Peripheral and Island Communities, http://www.merific.eu) and of MARINET, a European Community Research Infrastructure Action under the FP7 Capacities Specific Programme (262552) (www.fp7-marinet.eu). The authors would like to acknowledge the support of the South West Regional Development Agency for its support through the PRIMaRE institution and the support towards the FabTest through the Regional Growth Fund. The authors are grateful for the valuable support of the Ifremer team: Emmanuel Mansuy, Aurélien Tancray, Christophe Maisondieu and Peter Davies. The authors also want to thank Orcina for their technical support

Wide Field Astronomy at Dome C: two IR surveys complementary to SNAP

Surveys provide a wealth of data to the astronomical community that are used well after their completion. In this paper, we propose a project that would take the maximum benefit of Dome C in Antarctica by performing two surveys, in the wavelength range from 1-5 micron, complementary to SNAP space surveys. The first one over 1000 sq. deg. (1 KdF) for 4 years and the second one over 15 sq. deg (SNAP-IR) for the next 4 years at the same time as SNAP 0.35-1.7 microns survey. By using a Ground-Layer Adaptive Optics system, we would be able to recover, at the ice level and over at least half a degree in radius, the 300 mas angular resolution available above the 30-m high turbulent layer. Such a survey, combining a high angular resolution with high sensitivities in the NIR and MIR, should also play the role of a pre-survey for JWST and ALMA.Comment: Invited contribution to the 1st ARENA Conference on "Large Astronomical Infrastructures at CONCORDIA, prospects and constraints for Antarctic optical/IR Astronomy": 8 pages, 5 Postscript figure

Comorbidities of Idiopathic Thrombocytopenic Purpura: A Population-Based Study

A person experiencing more than one medical condition may have ambiguous clinical presentation. ITP is a serious autoimmune disease with little epidemiological evidence on its burden, risk factors, and comorbidities. Using the United Kingdom general practice research database, we conducted a 14 years population-based case control-type study to explore medical conditions more likely to cooccur with ITP and their temporal relationship in association with ITP. ITP patients were matched to non-ITP on practice, age, gender, and follow-up period. Potential comorbidities were represented by patients' medical information at the preferred term level of the MedDRA international classification. As well as death (OR = 60.0; 95% CI [4.47–806.0]) and known clinical signs and symptoms of ITP, ITP is associated with considerable number of medical conditions. The association between ITP and some of these conditions is apparent both before and after ITP diagnosis. Specific targeted studies can now be setup to reexamine observed associations

Poisoning by non-edible squash: retrospective series of 353 patients from French Poison Control Centers

CONTEXT: Among the numerous varieties of squash that exist, some are edible while other bitter-tasting ones are not fit for human consumption. Cases of confusion seem to be multiplying and are characterized by digestive problems (diarrhea, vomiting, and abdominal pain). METHODS: This is a descriptive retrospective study of cases of exposure reported to French Poison Control Centers between 1 January 2012 and 12 December 2016. RESULTS: 353 patients were included, with 71.7% belonging to collective cases of poisoning. The male to female sex ratio was 0.75 for an average age of 38.2 ± 23.6 years. The circumstances of exposure were dietary for 337 patients (95.5%). The majority of the squash consumed was purchased at a store (55.8%) but some also came from the garden (25.5%). 204 patients (57.8%) mostly presented with diarrhea, vomiting, abdominal pain, sometimes with the consequent dehydration, hypotension, tachycardia, headaches, or vertigo. There were no deaths or severe (Poisoning Severity Score (PSS) 3) cases, but there were 14 patients (4.0%) of moderate severity, 190 patients (53.8%) of minor severity (PSS 1), and 149 patients (42.2%) without severity (PSS 0) but among which we include the bitter taste of the squash. The average age of PSS 2 patients was significantly (p = .003) older than that of the PSS &lt;2 patients. CONCLUSION: As the first consequential series in Europe, our study shows that exposure to non-edible squash is frequent. Usually benign, poisoning could be the consequence of the irritating effect of certain cucurbits, the molecules responsible for the taste and toxicity of the fruits. In terms of prevention therefore, we recommend disposing of any squash with a bitter taste

The Gattini cameras for optical sky brightness measurements at Dome C, Antarctica

The Gattini cameras are two site testing instruments for the measurement of optical sky brightness, large area cloud cover and auroral detection of the night sky above the high altitude Dome C site in Antarctica. The cameras have been operating since installation in January 2006 and are currently at the end of the first Antarctic winter season. The cameras are transit in nature and are virtually identical both adopting Apogee Alta CCD detectors. By taking frequent images of the night sky we obtain long term cloud cover statistics, measure the sky background intensity as a function of solar and lunar altitude and phase and directly measure the spatial extent of bright aurora if present and when they occur. The full data set will return in December 2006 however a limited amount of data has been transferred via the Iridium network enabling preliminary data reduction and system evaluation. An update of the project is presented together with preliminary results from data taken since commencement of the winter season