Information methods for predicting risk and outcome of stroke

Stroke is a major cause of disability and mortality in most economically developed countries. It is the second leading cause of death worldwide (after cancer and heart disease) [55.1, 2] and a major cause of disability in adults in developed countries [55.3]. Personalized modeling is an emerging effective computational approach, which has been applied to various disciplines, such as in personalized drug design, ecology, business, and crime prevention; it has recently become more prominent in biomedical applications. Biomedical data on stroke risk factors and prognostic data are available in a large volume, but the data are complex and often difficult to apply to a specific person. Individualizing stroke risk prediction and prognosis will allow patients to focus on risk factors specific to them, thereby reducing their stroke risk and managing stroke outcomes more effectively. This chapter reviews various methods–conventional statistical methods and computational intelligent modeling methods for predicting risk and outcome of stroke

Lack of inhibition of thrombin-induced rise in intracellular Ca2+ levels and 5-hydroxytryptamine secretion by 1-oleoyl-2-acetylglycerol in human platelets

AbstractThe effect of 1-oleoyl-2-acetylglycerol (OAG) on the thrombin-induced rise in intracellular Ca2+ levels ([Ca2+]i) and 5-hydroxy[14C]tryptamine ([14C]5HT) secretion was studied. In washed human platelets prelabelled with [14C]5HT and quin 2, OAG (10–50 μgml) induced no significant aggregation, [14C]5HT secretion or rise in [Ca2+]i in the presence or absence of fibrinogen. However, addition of OAG (10–50 μgml) 10 s to 5 min before or 10–60 s after addition of threshold concentrations of thrombin ( < 0.03 Uml) resulted in a significant potentiation of aggregation and [14C]5HT secretion without any effect on the thrombin-induced rise in [Ca2+]i. Both EGTA, which abolished the latter and creatine phosphate/creatine phosphokinase, the ADP scavenger, totally inhibited the aggregation but only partially reduced [14C]5HT secretion in response to thrombin plus OAG. At higher concentrations of thrombin, neither the rise in [Ca2+]i nor the extent of [14C]5HT secretion was significantly altered by OAG addition. The results demonstrate that, unlike phorbol esters, OAG has no inhibitory effect on thrombin-induced [Ca2+]i mobilisation but can synergize with low concentrations of thrombin in potentiating [14C]5HT secretion even at basal [Ca2+]i

Optical characterisation of germanium optical fibres

Semiconductor core optical fibres are currently generating great interest as they promise to be a platform for the seamless incorporation of optoelectronic functionality into a new generation of all-fibre networks [1,2]. Although recent attentions have primarily focused on silicon as the material of choice for semiconductor photonics applications, germanium has some advantages over its counterpart. For example, it has higher nonlinearity, extended infrared transparency and has recently been demonstrated as a direct band gap laser medium [3]. Here we present the first optical characterisation of a germanium core optical fibre. The fibre was fabricated using a chemical micro fluidic deposition process [1] that uses GeH4 (germane) as a precursor to deposit amorphous germanium into the hole of a silica capillary. Figure 1 (a) shows an optical microscope image of the polished end face of a germanium fibre, with a 5.6 µm core diameter, which has been completely filled with the semiconductor material. Optical transmission measurements have been conducted over the wavelength range 2 µm to 11 µm, to confirm the broad mid-infrared operational window, and the guided output at 2.4 µm, imaged using a Spiricon Pyrocam III pyroelectric array camera, is shown in Figure 1 (b). At this wavelength the optical loss has been measured to be 20 dB/cm, which is comparable to losses measured for amorphous silicon fibres in the infrared. The potential for these germanium optical fibres to be used as optical modulators and infrared detectors will be discussed

Data mining framework for fatty liver disease classification in ultrasound: a hybrid feature extraction paradigm

PURPOSE: Fatty liver disease (FLD) is an increasing prevalent disease that can be reversed if detected early. Ultrasound is the safest and ubiquitous method for identifying FLD. Since expert sonographers are required to accurately interpret the liver ultrasound images, lack of the same will result in interobserver variability. For more objective interpretation, high accuracy, and quick second opinions, computer aided diagnostic (CAD) techniques may be exploited. The purpose of this work is to develop one such CAD technique for accurate classification of normal livers and abnormal livers affected by FLD. METHODS: In this paper, the authors present a CAD technique (called Symtosis) that uses a novel combination of significant features based on the texture, wavelet transform, and higher order spectra of the liver ultrasound images in various supervised learning-based classifiers in order to determine parameters that classify normal and FLD-affected abnormal livers. RESULTS: On evaluating the proposed technique on a database of 58 abnormal and 42 normal liver ultrasound images, the authors were able to achieve a high classification accuracy of 93.3% using the decision tree classifier. CONCLUSIONS: This high accuracy added to the completely automated classification procedure makes the authors' proposed technique highly suitable for clinical deployment and usage

A further 'degree of freedom' in the rotational evolution of stars

Observational and theoretical investigations provide evidence for non-uniform spot and magnetic flux distributions on rapidly rotating stars, which have a significant impact on their angular momentum loss rate through magnetised winds. Supplementing the formalism of MacGregor & Brenner (1991) with a latitude-dependent magnetised wind model, we analyse the effect of analytically prescribed surface distributions of open magnetic flux with different shapes and degrees of non-uniformity on the rotational evolution of a solar-like star. The angular momentum redistribution inside the star is treated in a qualitative way, assuming an angular momentum transfer between the rigidly-rotating radiative and convective zones on a constant coupling timescale of 15 Myr; for the sake of simplicity we disregard interactions with circumstellar disks. We find that non-uniform flux distributions entail rotational histories which differ significantly from those of classical approaches, with differences cumulating up to 200% during the main sequence phase. Their impact is able to mimic deviations of the dynamo efficiency from linearity of up to 40% and nominal dynamo saturation limits at about 35 times the solar rotation rate. Concentrations of open magnetic flux at high latitudes thus assist in the formation of very rapidly rotating stars in young open clusters, and ease the necessity for a dynamo saturation at small rotation rates. However, since our results show that even minor amounts of open flux at intermediate latitudes, as observed with Zeeman-Doppler imaging techniques, are sufficient to moderate this reduction of the AM loss rate, we suggest that non-uniform flux distributions are a complementary rather than an alternative explanation for very rapid stellar rotation.Comment: 12 pages, 13 figures, accepted for publication by A&

The burden of disease attributable to ambient PM2.5-bound PAHs exposure in Nagpur, India

Polycyclic aromatic hydrocarbons (PAHs) bound to PM2.5 are genotoxic carcinogens that can also elicit non-cancer effects. Previous studies report substantial burdens of PAHs-related lung cancer, but no estimate for other cancer types or non-carcinogenic burden. Here, we assessed the burden of disease, in DALYs/person/year, attributable to thirteen priority PAHs in PM2.5 in Nagpur district, for several endpoints linked to benzo[a]pyrene, to inform policy decision-making for mitigation. We conducted detailed assessment of concentrations of PAHs in nine areas, covering urban, peri-urban and rural environments, from February 2013 to June 2014. PAHs concentrations were converted to benzo[a]pyrene equivalent concentration for cancer and non-cancer effects using relative potency factors and relative toxicity factors derived from quantitative structure-activity relationships, respectively. We derived severity for each endpoint using GBD 2016 dataset. The annual average concentration of total PAHs in Nagpur district was 458±246 ng/m3, and results in 0.011 DALYs/person/year (49,000 DALYs/year), much higher than the WHO reference limit of 1×10-6 DALYs/person/year. PAHs-related burden follow this order: developmental (mostly cardiovascular) impairment (55.1%) > cancer (26.5%) or lung cancer (23.1%) > immunological impairment (18.0%) > reproductive abnormally (0.4%). The estimated DALYs/person/year is high. Mitigation intervention should target combustion sources having the highest level of exposure

The Coronal Structure of AB Doradus

We perform a numerical simulation of the corona of the young, rapidly rotating K0 dwarf AB Doradus using a global MHD model. The model is driven by a surface map of the radial magnetic field constructed using Zeeman-Doppler Imaging. We find that the global structure of the stellar corona is dominated by strong azimuthal tangling of the magnetic field due to the rapid rotation. The MHD solution enables us to calculate realistic Alfv\'en surfaces and we can therefore estimate the stellar mass loss rate and angular momentum loss rate without making undue theoretical simplifications. We consider three cases, parametrized by the base density of the corona, that span the range of possible solutions for the system. We find that overall, the mass and angular-momentum loss rates are higher than in the solar case; the mass loss rates are 10 to 500 times higher, and the angular momentum loss rate can be up to $3\times{10}^4$ higher than present day solar values. Our simulations show that this model can be use to constrain the wide parameter space of stellar systems. It also shows that an MHD approach can provide more information about the physical system over the commonly used potential field extrapolation.Comment: 13 pages, 7 figure