The use of ensemble empirical mode decomposition with canonical correlation analysis as a novel artifact removal technique

Biosignal measurement and processing is increasingly being deployed in ambulatory situations particularly in connected health applications. Such an environment dramatically increases the likelihood of artifacts which can occlude features of interest and reduce the quality of information available in the signal. If multichannel recordings are available for a given signal source, then there are currently a considerable range of methods which can suppress or in some cases remove the distorting effect of such artifacts. There are, however, considerably fewer techniques available if only a single-channel measurement is available and yet single-channel measurements are important where minimal instrumentation complexity is required. This paper describes a novel artifact removal technique for use in such a context. The technique known as ensemble empirical mode decomposition with canonical correlation analysis (EEMD-CCA) is capable of operating on single-channel measurements. The EEMD technique is first used to decompose the single-channel signal into a multidimensional signal. The CCA technique is then employed to isolate the artifact components from the underlying signal using second-order statistics. The new technique is tested against the currently available wavelet denoising and EEMD-ICA techniques using both electroencephalography and functional near-infrared spectroscopy data and is shown to produce significantly improved results. © 1964-2012 IEEE.

Weathering rinds as mirror images of palaeosols: Examples from the Western Alps with correlation to Antarctica and Mars

Weathering rinds have been used for decades as relative age indicators to differentiate glacial deposits in long Quaternary sequences, but only recently has it been shown that rinds contain long and extensive palaeoenvironmental records that often extend far beyond mere repositories of chemical weathering on both Earth and Mars. When compared with associated palaeosols in deposits of the same age, rinds often carry a zonal weathering record that can be correlated with palaeosol horizon characteristics, with respect to both abiotic and biotic parameters. As demonstrated with examples from the French and Italian Alps, rinds in coarse clastic sediment contain weathering zones that correlate closely with horizon development in associated palaeosols of presumed Late Glacial age. In addition to weathering histories in both rinds and palaeosols, considerable evidence exists to indicate that the black mat impact (12.8 ka) reached the European Alps, a connection with the Younger Dryas readvance supported by both mineral and chemical composition. Preliminary metagenomic microbial analysis using density gradient gel electrophoresis suggests that the eubacterial microbial population found in at least one Ah palaeosol horizon associated with a rind impact site is different from that in other Late Glacial and Younger Dryas surface palaeosol horizons. © 2013 The Geological Society of London.

Fluorescent switches with high selectivity towards sodium ions:Correlation of ion-induced conformation switching with fluorescence function

Diazacoronand 2 undergoes drastic conformational switching upon binding sodium ions as demonstrated by solution- and solid-state studies, which permit the design of efficient fluorescent PET (photoinduced electron transfer) switches 3a,b.

Sibling correlation of deficit syndrome in the Irish study of high-density schizophrenia families

The deficit syndrome is a subtype of schizophrenia characterized by primary and enduring negative features of psychopathology. It appears to reflect a distinct subtype within the syndrome of schizophrenia. Little is known about the familial or genetic aspects of the deficit syndrome. The purpose of this study was to determine whether deficit versus nondeficit subtypes are correlated in sibling pairs affected with schizophrenia.

Next generation sequencing-based molecular diagnosis of retinitis pigmentosa: identification of a novel genotype-phenotype correlation and clinical refinements

Retinitis pigmentosa (RP) is a devastating form of retinal degeneration, with significant social and professional consequences. Molecular genetic information is invaluable for an accurate clinical diagnosis of RP due to its high genetic and clinical heterogeneity. Using a gene capture panel that covers 163 of the currently known retinal disease genes, including 48 RP genes, we performed a comprehensive molecular screening in a collection of 123 RP unsettled probands from a wide variety of ethnic backgrounds, including 113 unrelated simplex and 10 autosomal recessive RP (arRP) cases. As a result, 61 mutations were identified in 45 probands, including 38 novel pathogenic alleles. Interestingly, we observed that phenotype and genotype were not in full agreement in 21 probands. Among them, eight probands were clinically reassessed, resulting in refinement of clinical diagnoses for six of these patients. Finally, recessive mutations in CLN3 were identified in five retinal degeneration patients, including four RP probands and one cone-rod dystrophy patient, suggesting that CLN3 is a novel non-syndromic retinal disease gene. Collectively, our results underscore that, due to the high molecular and clinical heterogeneity of RP, comprehensive screening of all retinal disease genes is effective in identifying novel pathogenic mutations and provides an opportunity to discover new genotype-phenotype correlations. Information gained from this genetic screening will directly aid in patient diagnosis, prognosis, and treatment, as well as allowing appropriate family planning and counseling.

Wave mixing by periodic nonlinear semiconductor multilayers

The properties of the combinatorial frequency generation and wave scattering by periodic stacks of nonlinear passive semiconductor layers are explored. It is demonstrated that the nonlinearity in passive weakly nonlinear semiconductor medium has the resistive nature associated with the dynamics of carriers. The features of the combinatorial frequency generation and the effects of the pump wave scattering and parameters of the constituent semiconductor layers on the efficiency of the frequency mixing are discussed and illustrated by the examples. © 2013 IEICE.

Combinatorial Frequency Generation in Quasi-Periodic Stacks of Nonlinear Dielectric Layers

Three-wave mixing in quasi-periodic structures (QPSs) composed of nonlinear anisotropic dielectric layers, stacked in Fibonacci and Thue-Morse sequences, has been explored at illumination by a pair of pump waves with dissimilar frequencies and incidence angles. A new formulation of the nonlinear scattering problem has enabled the QPS analysis as a perturbed periodic structure with defects. The obtained solutions have revealed the effects of stack composition and constituent layer parameters, including losses, on the properties of combinatorial frequency generation (CFG). The CFG features illustrated by the simulation results are discussed. It is demonstrated that quasi-periodic stacks can achieve a higher efficiency of CFG than regular periodic multilayers.

Correlation of Static Ageing Effects on Automotive Catalysts

This study identifies and analyzes the effect that aging time and temperature have on the CO light-off activity of three-way catalyst samples, aged in a static air (oxidizing) atmosphere. The bench aging time (BAT) equation proposed by the Environmental Protection Agency (EPA), which describes aging as dependent upon time at temperature, was used to calculate a range of oven aging times and temperatures based on a RAT-A engine bench aging cycle.

CO light-off tests carried out on cores aged between 800 and 900 °C have shown that it is the aging temperature that has the greatest effect on catalyst deterioration for static aging testing, with aging time having little effect. These results were in contradiction to the BAT equation, an industry norm for the aging of catalysts. This demonstrates that static aging, whilst showing how temperature affects aging, gives little or no time effects. The results have shown that static aging is not representative of actual aging on a vehicle.

Progressive aging conducted at a temperature of 1000 °C was shown to cause a decrease in catalyst activity as the aging time increased. However, even in these extreme conditions, static aging gave a slower rate of aging with time when compared to engine aging as defined by the BAT equation. Overall, static aging in air has been shown to produce a greater increase in aging due to temperature than predicted by the BAT equation, but less aging due to aging time.

Quantitative correlation of aflatoxin biomarker with dietary intake of aflatoxin in Tanzanian children

The association between aflatoxin intake from maize-based weaning food and aflatoxin albumin adducts (AF-alb) was investigated in 148 Tanzanian children aged between 12 and 22 months, at 2 visits 6 months apart. At the first visit (storage season) there was a significant correlation at the individual level between AF-alb (geometric mean 43.2 pg/mg albumin) and aflatoxin intake (geometric mean 81.7 ng/kg b.w./d) through maize-based weaning food (r = 0.51, p < 0.01). Overall, this correlation was r = 0.43 (p < 0.01). The AF-alb level in weaning-age children in Tanzania closely reflects aflatoxin intake from maize in weaning food. Exposure levels suggest children may be at risk from aflatoxin associated health effects.

Periodic Arrays of Interwoven Quadrifilar Spirals on Ferrite Substrates

The properties of metasurfaces composed of doubly periodic arrays of interwoven quadrifilar spiral conductors on magnetized ferrite substrates have been investigated with the aid of the full-wave electromagnetic simulator. The effects of incident wave polarization and ferrite magnetization on the scattering characteristics have been analysed at both normal and in-plane dc magnetic bias. The features of the fundamental topological resonances in the interwoven spiral arrays on ferrite substrates are illustrated by the simulation results and the effects of ferrite gyrotropy and dispersion on the array resonance response and fractional bandwidth are discussed.

Correlation of phantom-based and log file patient-specific QA with complexity scores for VMAT

The motivation for this study was to reduce physics workload relating to patient- specific quality assurance (QA). VMAT plan delivery accuracy was determined from analysis of pre- and on-treatment trajectory log files and phantom-based ionization chamber array measurements. The correlation in this combination of measurements for patient-specific QA was investigated. The relationship between delivery errors and plan complexity was investigated as a potential method to further reduce patient-specific QA workload. Thirty VMAT plans from three treatment sites - prostate only, prostate and pelvic node (PPN), and head and neck (H&amp;N) - were retrospectively analyzed in this work. The 2D fluence delivery reconstructed from pretreatment and on-treatment trajectory log files was compared with the planned fluence using gamma analysis. Pretreatment dose delivery verification was also car- ried out using gamma analysis of ionization chamber array measurements compared with calculated doses. Pearson correlations were used to explore any relationship between trajectory log file (pretreatment and on-treatment) and ionization chamber array gamma results (pretreatment). Plan complexity was assessed using the MU/ arc and the modulation complexity score (MCS), with Pearson correlations used to examine any relationships between complexity metrics and plan delivery accu- racy. Trajectory log files were also used to further explore the accuracy of MLC and gantry positions. Pretreatment 1%/1 mm gamma passing rates for trajectory log file analysis were 99.1% (98.7%-99.2%), 99.3% (99.1%-99.5%), and 98.4% (97.3%-98.8%) (median (IQR)) for prostate, PPN, and H&amp;N, respectively, and were significantly correlated to on-treatment trajectory log file gamma results (R = 0.989, p &lt; 0.001). Pretreatment ionization chamber array (2%/2 mm) gamma results were also significantly correlated with on-treatment trajectory log file gamma results (R = 0.623, p &lt; 0.001). Furthermore, all gamma results displayed a significant correlation with MCS (R &gt; 0.57, p &lt; 0.001), but not with MU/arc. Average MLC position and gantry angle errors were 0.001 ± 0.002 mm and 0.025° ± 0.008° over all treatment sites and were not found to affect delivery accuracy. However, vari- ability in MLC speed was found to be directly related to MLC position accuracy. The accuracy of VMAT plan delivery assessed using pretreatment trajectory log file fluence delivery and ionization chamber array measurements were strongly correlated with on-treatment trajectory log file fluence delivery. The strong corre- lation between trajectory log file and phantom-based gamma results demonstrates potential to reduce our current patient-specific QA. Additionally, insight into MLC and gantry position accuracy through trajectory log file analysis and the strong cor- relation between gamma analysis results and the MCS could also provide further methodologies to both optimize the VMAT planning and QA process. 

Process efficiency in polymer extrusion: Correlation between the energy demand and melt thermal stability

Thermal stability is of major importance in polymer extrusion, where product quality is dependent upon the level of melt homogeneity achieved by the extruder screw. Extrusion is an energy intensive process and optimisation of process energy usage while maintaining melt stability is necessary in order to produce good quality product at low unit cost. Optimisation of process energy usage is timely as world energy prices have increased rapidly over the last few years. In the first part of this study, a general discussion was made on the efficiency of an extruder. Then, an attempt was made to explore correlations between melt thermal stability and energy demand in polymer extrusion under different process settings and screw geometries. A commodity grade of polystyrene was extruded using a highly instrumented single screw extruder, equipped with energy consumption and melt temperature field measurement. Moreover, the melt viscosity of the experimental material was observed by using an off-line rheometer. Results showed that specific energy demand of the extruder (i.e. energy for processing of unit mass of polymer) decreased with increasing throughput whilst fluctuation in energy demand also reduced. However, the relationship between melt temperature and extruder throughput was found to be complex, with temperature varying with radial position across the melt flow. Moreover, the melt thermal stability deteriorated as throughput was increased, meaning that a greater efficiency was achieved at the detriment of melt consistency. Extruder screw design also had a significant effect on the relationship between energy consumption and melt consistency. Overall, the relationship between the process energy demand and thermal stability seemed to be negatively correlated and also it was shown to be highly complex in nature. Moreover, the level of process understanding achieved here can help to inform selection of equipment and setting of operating conditions to optimise both energy and thermal efficiencies in parallel. 

Lack of in vitro-in vivo correlation for a UC781-releasing vaginal ring in macaques

This study describes the preclinical development of a matrix-type silicone elastomer vaginal ring device designed to provide controlled release of UC781, a non-nucleoside re- verse transcriptase inhibitor. Testing of both human- and macaque-sized rings in a sink condition in vitro release model demonstrated continuous UC781 release in quantities consid- ered sufficient to maintain vaginal fluid concentrations at levels 82–860-fold higher than the in vitro IC50 (2.0 to 10.4 nM) and therefore potentially protect against mucosal trans- mission of HIV. The 100-mg UC781 rings were well tolerated in pig-tailed macaques, did not induce local inflammation as determined by cytokine analysis and maintained median con- centrations in vaginal fluids of UC781 in the range of 0.27 to 5.18 mM during the course of the 28-day study. Analysis of residual UC781 content in rings after completion of both the in vitro release and macaque pharmacokinetic studies revealed that 57 and 5 mg of UC781 was released, respectively. The pharmacokinetic analysis of a 100-mg UC781 vaginal ring in pig-tailed macaques showed poor in vivo–in vitro correlation, attributed to the very poor solubility of UC781 in vaginal fluid and resulting in a dissolution-controlled drug release mecha- nism rather than the expected diffusion-controlled mechanism.