Non-Linearity Corrections and Statistical Uncertainties Associated with Near-Infrared Arrays

We derive general equations for non-linearity corrections and statistical uncertainty (variance) estimates for data acquired with near-infrared detectors employing correlated double sampling, multiple correlated double sampling (Fowler sampling) and uniformly-spaced continuous readout techniques. We compare our equation for the variance on each pixel associated with Fowler sampling with measurements obtained from data taken with the array installed in the near-infrared cross-dispersed spectrograph (SpeX) at the NASA Infrared Telescope Facility and find that it provides an accurate representation of the empirical results. This comparison also reveals that the read noise associated with a single readout of the SpeX array increases with the number of non-destructive reads, n_r, as n_r^0.16. This implies that the {effective} read noise of a stored image decreases as n_r^-0.34, shallower than the expected rate of n_r^-0.5. The cause of this read noise behavior is uncertain, but may be due to heating of the array as a result of the multiple read outs. Such behavior may be generic to arrays that employ correlated or multiple correlated double sampling readouts.Comment: 21 pages, accepted by PAS

How strongly do word reading times and lexical decision times correlate? Combining data from eye movement corpora and megastudies

We assess the amount of shared variance between three measures of visual word recognition latencies: eye movement latencies, lexical decision times and naming times. After partialling out the effects of word frequency and word length, two well-documented predictors of word recognition latencies, we see that 7-44% of the variance is uniquely shared between lexical decision times and naming times, depending on the frequency range of the words used. A similar analysis of eye movement latencies shows that the percentage of variance they uniquely share either with lexical decision times or with naming times is much lower. It is 5 – 17% for gaze durations and lexical decision times in studies with target words presented in neutral sentences, but drops to .2% for corpus studies in which eye movements to all words are analysed. Correlations between gaze durations and naming latencies are lower still. These findings suggest that processing times in isolated word processing and continuous text reading are affected by specific task demands and presentation format, and that lexical decision times and naming times are not very informative in predicting eye movement latencies in text reading once the effect of word frequency and word length are taken into account. The difference between controlled experiments and natural reading suggests that reading strategies and stimulus materials may determine the degree to which the immediacy-of-processing assumption and the eye-mind assumption apply. Fixation times are more likely to exclusively reflect the lexical processing of the currently fixated word in controlled studies with unpredictable target words rather than in natural reading of sentences or texts

A prototype system for observing the Atlantic Meridional Overturning Circulation - scientific basis, measurement and risk mitigation strategies, and first results

The Atlantic Meridional Overturning Circulation (MOC) carries up to one quarter of the global northward heat transport in the Subtropical North Atlantic. A system monitoring the strength of the MOC volume transport has been operating since April 2004. The core of this system is an array of moored sensors measuring density, bottom pressure and ocean currents. A strategy to mitigate risks of possible partial failures of the array is presented, relying on backup and complementary measurements. The MOC is decomposed into five components, making use of the continuous moored observations, and of cable measurements across the Straits of Florida, and wind stress data. The components compensate for each other, indicating that the system is working reliably. The year-long average strength of the MOC is 18.7±5.6 Sv, with wind-driven and density-inferred transports contributing equally to the variability. Numerical simulations suggest that the surprisingly fast density changes at the western boundary are partially linked to westward propagating planetary wave

Contextualising the Permian Sumdo eclogite belt, Lhasa block, Tibet

Abstract HKT-ISTP 2013 A

Far-Infrared Observations Of A Massive Cluster Forming In The Monoceros R2 Filament Hub

We present far-infrared observations of Monoceros R2 (a giant molecular cloud at approximately 830 pc distance, containing several sites of active star formation), as observed at 70 μm, 160 μm, 250 μm, 350 μm, and 500 μm by the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on the Herschel Space Observatory as part of the Herschel imaging survey of OB young stellar objects (HOBYS) Key programme. The Herschel data are complemented by SCUBA-2 data in the submillimetre range, and WISE and Spitzer data in the mid-infrared. In addition, C18O data from the IRAM 30-m Telescope are presented, and used for kinematic information. Sources were extracted from the maps with getsources, and from the fluxes measured, spectral energy distributions were constructed, allowing measurements of source mass and dust temperature. Of177 Herschel sources robustly detected in the region (a detection with high signal-to-noise and low axis ratio at multiple wavelengths), including protostars and starless cores, 29 are found in a filamentary hub at the centre of the region (a little over 1% of the observed area). These objects are on average smaller, more massive, and more luminous than those in the surrounding regions (which together suggest that they are at a later stage of evolution), a result that cannot be explained entirely by selection effects. These results suggest a picture in which the hub may have begun star formation at a point significantly earlier than the outer regions, possibly forming as a result of feedback from earlier star formation. Furthermore, the hub may be sustaining its star formation by accreting material from the surrounding filaments

Registration of amiloride in South Africa: Cutting the Gordian knot

Amiloride is an antagonist of the renal tubular epithelial sodium channel (ENaC). As such, it is a diuretic that is both potassium and magnesium sparing. It is used for the treatment of potassium depletion and hypertension, and is the specific therapy for hypertension due to overactivity of the ENaC (Liddle syndrome and several additional genetic causes of the Liddle phenotype - low renin and low aldosterone). It is listed as a World Health Organization essential drug, but has never been registered in South Africa (SA) and can therefore only be prescribed under a Section 21 application to the SA Health Products Regulatory Authority (SAHPRA) on a case-by-case basis. In SA, \u3e50% of patients treated for hypertension are not controlled. In the USA, the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study reported that African Americans are more likely to be diagnosed with hypertension, more likely to be treated, more likely to be treated intensively, and less likely to achieve blood pressure (BP) control. Although the reasons are complex, studies show that 10 - 20% of blacks may carry the Liddle phenotype. Observational data and a controlled clinical trial done in three African countries have shown that these patients respond to amiloride and not to conventional guideline-based antihypertensive treatment. The former is likely to result in a significant reduction in cardiovascular, stroke and kidney morbidity and mortality, because of improved BP control. Amiloride is very unlikely to ever be registered in SA, as it was first developed \u3e50 years ago, and SAHPRA regulations prevent widespread prescription of this essential drug. This is a classic Gordian knot that requires a novel approach from authorities to sever the knot and improve the health of many South Africans

Effects of syntactic context on eye movements during reading

Previous research has demonstrated that properties of a currently fixated word and of adjacent words influence eye movement control in reading. In contrast to such local effects, little is known about the global effects on eye movement control, for example global adjustments caused by processing difficulty of previous sentences. In the present study, participants read text passages in which voice (active vs. passive) and sentence structure (embedded vs. non-embedded) were manipulated. These passages were followed by identical target sentences. The results revealed effects of previous sentence structure on gaze durations in the target sentence, implying that syntactic properties of previously read sentences may lead to a global adjustment of eye movement control