Single-channel Measurements Research Articles

Short-coupled polymorphic ventricular tachycardia at rest linked to a novel ryanodine receptor (RyR2) mutation: Leaky RyR2 channels under non-stress conditions

BackgroundRyanodine receptor (RyR2) mutations have largely been associated with catecholaminergic polymorphic ventricular tachycardia (PMVT). The role of RyR2 mutations in the pathogenesis of arrhythmias and syncope at rest is unknown. We sought to characterize the clinical and functional characteristics associated with a novel RyR2 mutation found in a mother and daughter with PMVT at rest. Methods and resultsA 31-year-old female with syncope at rest and recurrent short-coupled premature ventricular contractions (PVCs) initiating PMVT was found to be heterozygous for a novel RyR2-H29D mutation. Her mother, who also had syncope at rest and short-coupled PMVT, was found to harbor the same mutation. Human RyR2-H29D mutant channels were generated using site-directed mutagenesis and heterologously expressed in HEK293 cells together with the stabilizing protein calstabin2 (FKPB12.6). Single channel measurements of RyR2-H29D mutant channels and wild type (WT) RyR2 channels were compared at varying concentrations of cytosolic Ca2+. Binding affinities of the RyR2-H29D channels and RyR2-WT channels to calstabin2 were compared. Functional characterization of the RyR2-H29D mutant channel revealed significantly higher open probability and opening frequency at diastolic levels of cytosolic Ca2+ under non-stress conditions without protein kinase A treatment. This was associated with a modest depletion of calstabin2 binding under resting conditions. ConclusionsThe RyR2-H29D mutation is associated with a clinical phenotype of short-coupled PMVT at rest. In contrast to catecholaminergic PMVT-associated RyR2 mutations, RyR2-H29D causes a leaky channel at diastolic levels of Ca2+ under non-stress conditions. Leaky RyR2 may be an under-recognized mechanism for idiopathic PMVT at rest.

A polarization-sensitive light field imager for multi-channel angular spectroscopy of light scattering in biological tissues.

Angular spectroscopy of light scattering can be used for quantitative analysis of cellular and subcellular properties, and thus promises a noninvasive methodology for in vivo assessment cellular integrity to complement in vitro histological examination. Spatial information is essential for accurate identification of localized abnormalities. However, conventional angular spectroscopy systems only provide single-channel measurement, which suffers from poor spatial resolution or requires time-consuming scanning over extended area. The purpose of this study was to develop a multi-channel angular spectroscopy for light field imaging in biological tissues. A microlens array (MLA) (8×8) based light field imager for 64-channel angular spectroscopy was developed. A pair of crossed polarizers was employed for polarization-sensitive recording to enable quantitative measurement at high signal specificity and sensitivity. The polarization-sensitive light field imager enables rapid measurement of multiple sampling volumes simultaneously at 18 μm spatial-resolution and 3° angular-resolution. Comparative light field imaging and electrophysiological examination of freshly isolated and physiologically deteriorated lobster leg nerves have been conducted. Two-dimensional (2D) polarization-sensitive scattering patterns of the fresh nerves were highly elliptical, while they gradually lost the ellipticity and became rotationally symmetric (i.e., circular) as the nerves physiologically deteriorated due to repeated electrical stimulations. Characterized parameters, i.e., the ellipticity and the scattering intensity, rendered spatially various characteristics such as different values and deteriorating rates. The polarization-sensitive light field imager is able to provide multi-channel angular spectroscopy of light scattering with both spatial and angular resolutions. The light scattering properties of nerves are highly dependent on the orientation of nerves and their physiological status. Further development of polarization-sensitive multi-channel angular spectroscopy may promise a methodology for rapid and reliable identification of localized abnormalities in biological tissues.

Monovalent Cationic Channel Activity in the Inner Membrane of Nuclei from Skeletal Muscle Fibers

Nuclear ion channels remain among the least studied and biophysically characterized channels. Although considerable progress has been made in characterizing calcium release channels in the nuclear membrane, very little is known regarding the properties of nuclear monovalent cationic channels. Here, we describe a method to isolate nuclei from adult skeletal muscle fibers that are suitable for electrophysiological experiments. Using this approach, we show for the first time, to our knowledge, that a nuclear monovalent cationic channel (NMCC) is prominently expressed in the inner membrane of nuclei isolated from flexor digitorum brevis skeletal muscle fibers of adult mice. In isotonic 140 mM KCl, the skeletal muscle NMCC exhibits a unitary conductance of ∼160 pS and high, voltage-independent open probability. Based on single-channel reversal potential measurements, NMCCs are slightly more permeable to potassium ions over sodium (PK/PNa = 2.68 ± 0.21) and cesium (PK/PCs = 1.39 ± 0.03) ions. In addition, NMCCs do not permeate divalent cations, are inhibited by calcium ions, and demonstrate weak rectification in asymmetric Ca2+-containing solutions. Together, these studies characterize a voltage-independent NMCC in skeletal muscle, the properties of which are ideally suited to serve as a countercurrent mechanism during calcium release from the nuclear envelope.

천리안위성 기상 탑재체의 가시 채널 관측을 이용한 지표면 반사도 산출 - 배경광학두께 보정의 효과 분석 -

인공위성의 가시 영역 관측으로부터 에어로솔의 정량적인 정보를 산출하는데 있어, 지표면 반사도의 보정은 매우 중요한 역할을 한다. 이에 본 연구에서는 두 가지 방법을 이용하여 천리안위성의 기상탑재체로부터 관측된 가시채널의 반사도로부터 지표면 반사도를 산출하고, 상호 비교 하여 정확도를 검증하고자 하였다. 첫 번째 방법은 최소 반사도법으로, 동일한 화소에서 일정 기간 동안 관측된 반사도 중 최소값이 에어로솔에 의한 영향 없이 지표반사에 의한 영향만을 포함한다는 가정을 기반으로, 대기산란 효과를 보정하여 지표면 반사도를 산출하는 방법이다. 두 번째 방법은 미리 알고 있는 에어로솔 정보를 고려하여 대기-에어로솔 효과를 보정함으로써 지표면 반사도를 얻는 것으로 본 연구에서 대기 보정법 이라 칭한다. 두 번째 방법을 적용하기 위해서는 정확한 에어로솔 정보가 요구되므로, 에어로솔 광학두께의 오차범위가 0.01 (<TEX>${\geq}440nm$</TEX>) 이내인 것으로 알려진 AERONET의 산출물을 이용하였다. 본 연구의 주요 목적은 최소 반사도법을 통하여 산출되는 지표면 반사도가 어느 정도의 정확도를 가지는지를 파악하는데 있어, 대기 보정법을 통하여 산출되는 값을 기준 값으로 두고 비교 분석을 수행하였다. 또한, 대기 중 존재하는 배경광학두께가 최소 반사도법의 정확도에 미치는 영향을 분석해보고자 하였다. 서울 지역에서 2012년 봄철 기간(3월 ~ 5월)동안 AERONET 관측지점에서 산출된 결과를 분석 한 결과, 대기 보정법을 통해 산출된 지표면 반사도의 평균이 0.108로 나타났고, 배경광학두께에 대한 고려 없이 최소 반사도법을 통하여 산출된 지표면 반사도는 그에 비해 약 0.012 높은 값을 보였다. 한 편 배경광학두께를 고려하였을 경우 그 차이는 0.010으로 감소하여, 정확도 향상에 기여하였음을 확인하였다. Accurate correction of surface effect from back scattered solar radiance is one of key issue to retrieve aerosol information from satellite measurements. In this study, two different methods are applied to retrieve surface reflectance by using single visible channel measurement from meteorological imager onboard COMS. The first one is minimum reflectance method, which composes the minimum value among previously measured reflectances at each pixel over a certain search window length. This method assumes that the darkest pixel corresponds to the aerosol-free condition, and deduces surface reflectance by correcting atmospheric scattering from the measured visible reflectance. The second method, named as the "atmospheric correction method" in this study, estimates the result by correcting aerosol and atmospheric scattering with ground-based observation of aerosol optical properties. The purpose of this study is to investigate the retrieval accuracy of the widelyused minimum reflectance method. Also, the retrieval error caused by the loading of background aerosol is mainly estimated. The comparison between surface reflectances retrieved from the two methods shows good agreement with the correlation coefficient of 0.87. However, the results from the minimum reflectance method are slightly overestimated than the values from the atmospheric correction method when surface reflectance is lower than 0.2. The average difference between the two results is 0.012 without the background aerosol correction. By considering the background aerosol effect, however, the difference is reduced to 0.010.

Study of the Protein Complex, Pore Diameter, and Pore-forming Activity of the Borrelia burgdorferi P13 Porin

P13 is one of the major outer membrane proteins of Borrelia burgdorferi. Previous studies described P13 as a porin. In the present study some structure and function aspects of P13 were studied. P13 showed according to lipid bilayer studies a channel-forming activity of 0.6 nanosiemens in 1 m KCl. Single channel and selectivity measurements demonstrated that P13 had no preference for either cations or anions and showed no voltage-gating up to ±100 mV. Blue native polyacrylamide gel electrophoresis was used to isolate and characterize the P13 protein complex in its native state. The complex had a high molecular mass of about 300 kDa and was only composed of P13 monomers. The channel size was investigated using non-electrolytes revealing an apparent diameter of about 1.4 nm with a 400-Da molecular mass cut-off. Multichannel titrations with different substrates reinforced the idea that P13 forms a general diffusion channel. The identity of P13 within the complex was confirmed by second dimension SDS-PAGE, Western blotting, mass spectrometry, and the use of a p13 deletion mutant strain. The results suggested that P13 is the protein responsible for the 0.6-nanosiemens pore-forming activity in the outer membrane of B. burgdorferi.

Single- and multi-channel modulation detection in cochlear implant users.

Single-channel modulation detection thresholds (MDTs) have been shown to predict cochlear implant (CI) users’ speech performance. However, little is known about multi-channel modulation sensitivity. Two factors likely contribute to multichannel modulation sensitivity: multichannel loudness summation and the across-site variance in single-channel MDTs. In this study, single- and multi-channel MDTs were measured in 9 CI users at relatively low and high presentation levels and modulation frequencies. Single-channel MDTs were measured at widely spaced electrode locations, and these same channels were used for the multichannel stimuli. Multichannel MDTs were measured twice, with and without adjustment for multichannel loudness summation (i.e., at the same loudness as for the single-channel MDTs or louder). Results showed that the effect of presentation level and modulation frequency were similar for single- and multi-channel MDTs. Multichannel MDTs were significantly poorer than single-channel MDTs when the current levels of the multichannel stimuli were reduced to match the loudness of the single-channel stimuli. This suggests that, at equal loudness, single-channel measures may over-estimate CI users’ multichannel modulation sensitivity. At equal loudness, there was no significant correlation between the amount of multichannel loudness summation and the deficit in multichannel MDTs, relative to the average single-channel MDT. With no loudness compensation, multichannel MDTs were significantly better than the best single-channel MDT. The across-site variance in single-channel MDTs varied substantially across subjects. However, the across-site variance was not correlated with the multichannel advantage over the best single channel. This suggests that CI listeners combined envelope information across channels instead of attending to the best channel.

Time-Frequency Analysis of Cabin Noise Using EEMD-ICA Approaches

The interior noise of construction machinery is complex non-stationary signal caused by a variety of excitation source; the noise source must be determined to minimize its radiation. 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. The combined techniques of empirical mode decomposition (EEMD) and the improvement of independent component analysis (ICA) were applied to analysis the parotic noise signals of bulldozer cabin in our study. According to the correlated measurement standard, the combining method of experiment and analysis for the cabin interior and outside noise and vibration signals was applied to research the noise source effectively. With the experiment and coherence analysis for the cabin interior and outside noise and vibration signals, the techniques of EEMD-ICA were valid on the noise source separation and identification. Taking into account the machine running characteristics and the layout of machine structures, and based on the frequency characteristics of the noise and vibration signals, we concluded that the main sources of indoor noise was combustion noise of diesel engine and mechanical radiation noise of cabin parts caused by the diesel engine vibration transmission. Generation of noise sources, transmission paths of air-borne or structure-borne noises were well researched in order to control the interior noise. Finally, some modifications were taken for different noise sources and the noise level was reduced to a satisfied level.

Cytochalasin E alters the cytoskeleton and decreases ENaC activity in Xenopus 2F3 cells.

Numerous reports have linked cytoskeleton-associated proteins with the regulation of epithelial Na(+) channel (ENaC) activity. The purpose of the present study was to determine the effect of actin cytoskeleton disruption by cytochalasin E on ENaC activity in Xenopus 2F3 cells. Here, we show that cytochalasin E treatment for 60 min can disrupt the integrity of the actin cytoskeleton in cultured Xenopus 2F3 cells. We show using single channel patch-clamp experiments and measurements of short-circuit current that ENaC activity, but not its density, is altered by cytochalasin E-induced disruption of the cytoskeleton. In nontreated cells, 8 of 33 patches (24%) had no measurable ENaC activity, whereas in cytochalasin E-treated cells, 17 of 32 patches (53%) had no activity. Analysis of those patches that did contain ENaC activity showed channel open probability significantly decreased from 0.081 ± 0.01 in nontreated cells to 0.043 ± 0.01 in cells treated with cytochalasin E. Transepithelial current from mpkCCD cells treated with cytochalasin E, cytochalasin D, or latrunculin B for 60 min was decreased compared with vehicle-treated cells. The subcellular expression of fodrin changed significantly, and several protein elements of the cytoskeleton decreased at least twofold after 60 min of cytochalasin E treatment. Cytochalasin E treatment disrupted the association between ENaC and myristoylated alanine-rich C-kinase substrate. The results presented here suggest disruption of the actin cytoskeleton by different compounds can attenuate ENaC activity through a mechanism involving changes in the subcellular expression of fodrin, several elements of the cytoskeleton, and destabilization of the ENaC-myristoylated alanine-rich C-kinase substrate complex.

An iterative longest matching segment approach to speech enhancement with additive noise and channel distortion

This paper presents a new approach to speech enhancement from single-channel measurements involving both noise and channel distortion (i.e., convolutional noise), and demonstrates its applications for robust speech recognition and for improving noisy speech quality. The approach is based on finding longest matching segments (LMS) from a corpus of clean, wideband speech. The approach adds three novel developments to our previous LMS research. First, we address the problem of channel distortion as well as additive noise. Second, we present an improved method for modeling noise for speech estimation. Third, we present an iterative algorithm which updates the noise and channel estimates of the corpus data model. In experiments using speech recognition as a test with the Aurora 4 database, the use of our enhancement approach as a preprocessor for feature extraction significantly improved the performance of a baseline recognition system. In another comparison against conventional enhancement algorithms, both the PESQ and the segmental SNR ratings of the LMS algorithm were superior to the other methods for noisy speech enhancement.

Catalyst-like modulation of transition states for CFTR channel opening and closing: New stimulation strategy exploits nonequilibrium gating

Cystic fibrosis transmembrane conductance regulator (CFTR) is the chloride ion channel mutated in cystic fibrosis (CF) patients. It is an ATP-binding cassette protein, and its resulting cyclic nonequilibrium gating mechanism sets it apart from most other ion channels. The most common CF mutation (ΔF508) impairs folding of CFTR but also channel gating, reducing open probability (Po). This gating defect must be addressed to effectively treat CF. Combining single-channel and macroscopic current measurements in inside-out patches, we show here that the two effects of 5-nitro-2-(3-phenylpropylamino)benzoate (NPPB) on CFTR, pore block and gating stimulation, are independent, suggesting action at distinct sites. Furthermore, detailed kinetic analysis revealed that NPPB potently increases Po, also of ΔF508 CFTR, by affecting the stability of gating transition states. This finding is unexpected, because for most ion channels, which gate at equilibrium, altering transition-state stabilities has no effect on Po; rather, agonists usually stimulate by stabilizing open states. Our results highlight how for CFTR, because of its unique cyclic mechanism, gating transition states determine Po and offer strategic targets for potentiator compounds to achieve maximal efficacy.

Sleep apnea classification using ECG-signal wavelet-PCA features.

Sleep apnea is often diagnosed using an overnight sleep test called a polysomnography (PSG). Unfortunately, though it is the gold standard of sleep disorder diagnosis, a PSG is time consuming, inconvenient, and expensive. Many researchers have tried to ameliorate this problem by developing other reliable methods, such as using electrocardiography (ECG) as an observed signal source. Respiratory rate interval, ECG-derived respiration, and heart rate variability analysis have been studied recently as a means of detecting apnea events using ECG during normal sleep, but these methods have performance weaknesses. Thus, the aim of this study is to classify the subject into normal- or apnea-subject based on their single-channel ECG measurement in regular sleep. In this proposed study, ECG is decomposed into five levels using wavelet decomposition for the initial processing to determine the detail coefficients (D3-D5) of the signal. Approximately 15 features were extracted from every minute of ECG. Principal component analysis and a support vector machine are used for feature dimension reduction and classification, respectively. According to classification that been done from a data set consisting of thirty-five patients, the proposed minute-to-minute classifier specificity, sensitivity, and subject-based classification accuracy are 95.20%, 92.65%, and 94.3%, respectively. Furthermore, the proposed system can be used as a basis for future development of sleep apnea screening tools.

Phosphorylation of Maurocalcine Strongly Modifies its Effect on Type 1 Ryanodine Receptor

Maurocalcine (MCa) is a 33-amino acid peptide isolated from the venom of Scorpio maurus palmatus, a Tunisian scorpion. It possesses efficient cell penetration properties and has been shown to strongly modify ryanodine receptor (RyR1) channel behavior by increasing open probability and inducing a long-lasting subconductance state. The amino acid residue threonine at position 26 belongs to a putative phosphorylation site within MCa sequence. We investigated the effect of a) T26 phosphorylation (MCa T26Phospho) by protein kinase A and b) replacement of T26 by glutamic acid residue to mimic phosphorylation on the effect of MCa on RyR1 properties. Using [3H]ryanodine ([3H]Ry) binding and single channel voltage-clamp measurements, we show that both MCa T26Phospho and MCa T26E analogs almost completely lose the ability to induce RyR1 activation. Neither MCa T26Phospho nor MCa T26E (up to 2µM) increase [3H]rya binding. Small increase (∼1.65-fold activation; p<0.01) was observed with high concentrations (10µM) of either MCa T26Phospho or MCa T26E. Single channel measurements revealed that neither MCa T26E nor MCa T26Phospho (up to 2µM) were able to induce the characteristic long-lasting subconductance state of RyR1 observed in presence of wild-type MCa. MCa T26Phospho altered RyR1 channel gating in a time-dependent biphasic manner with initial activation of Po followed by almost complete inactivation. These effects of MCa T26Phospho could be reversed by 200nM wt MCa. At concentrations ≥2μM, MCa T26E enhances Po∼3 fold by shortening τc without altering τo. These results show that single phosphorylation of MCa modifies RyR1 activity.1P01 AR52354.

Effects of a Non-Hydrolyzable ADP-Ribose Analog on the Gating of the TRPM2 Channel

TRPM2 is a non-selective Ca2+ permeable cation channel co-activated by intracellular Ca2+ and ADP-ribose (ADPR). ADPR binds to the C-terminal NUDT9-H domain. Intriguingly, when expressed in isolation, the NUDT9-H domain functions as an active ADPR hydrolase which breaks ADPR into AMP and ribose-5-phosphate. To exploit the relevance of this putative activity for channel gating, we examined the effect of AMPCPR-, a non-hydrolyzable ADPR analogue, on TRPM2 channel gating using macroscopic measurements and steady-state single-channel kinetic analysis. In biochemical experiments purified NUDT9, a mitochondrial ADPR-pyrophosphatase, showed efficient hydrolysis of ADPR, but completely failed to cleave AMPCPR.When applied to inside-out patches the apparent affinity of AMPCPR for TRPM2 activation was two orders of magnitude lower compared to ADPR (K1/2ADPR≈1μM, K1/2AMPCPR≈80μM), and even at a saturating concentration, it could only partially stimulate TRPM2 activity.We also compared macroscopic current relaxation time courses in response to sudden removal of ADPR or AMPCPR. The current decay time constant was almost four times shorter after AMPCPR removal than following ADPR withdrawal.In steady-state single-channel measurements TRPM2 shows bursting behaviour when gated by either nucleotide. We compared mean open times and mean burst durations in the presence of ADPR or AMPCPR. These parameters were independent of the concentrations of the agonists, but both were significantly shorter in the presence of AMPCPR.Our results identify AMPCPR as a low-affinity partial agonist. The fact that channel closing rate is not slowed in the presence of a non-hydrolyzable ligand suggests either that the NUDT9-H domain has no ADPR hydrolase activity, or that the latter is not required for channel closure.

Importance of indole N[sbnd]H hydrogen bonding in the organization and dynamics of gramicidin channels

The linear ion channel peptide gramicidin represents an excellent model for exploring the principles underlying membrane protein structure and function, especially with respect to tryptophan residues. The tryptophan residues in gramicidin channels are crucial for the structure and function of the channel. In order to test the importance of indole hydrogen bonding for the biophysical properties of gramicidin channels, we monitored the effect of N-methylation of gramicidin tryptophans, using a combination of steady state and time-resolved fluorescence approaches along with circular dichroism spectroscopy. We show here that in the absence of the hydrogen bonding ability of tryptophans, tetramethyltryptophan gramicidin (TM-gramicidin) is unable to maintain the single stranded, head-to-head dimeric channel conformation in membranes. Our results show that TM-gramicidin displays a red-shifted fluorescence emission maximum, lower red edge excitation shift (REES), and higher fluorescence intensity and lifetime, consistent with its nonchannel conformation. This is in agreement with the measured location (average depth) of the 1-methyltryptophans in TM-gramicidin using the parallax method. These results bring out the usefulness of 1-methyltryptophan as a fluorescent tool to examine the hydrogen bonding ability of tryptophans in proteins and peptides. We conclude that changes in the hydrogen bonding ability of tryptophans, along with coupled changes in peptide backbone structure induce the loss of single stranded β6.3 helical dimer conformation. These results agree with earlier results from size-exclusion chromatography and single-channel measurements for TM-gramicidin, and confirm the importance of indole hydrogen bonding for the conformation and function of ion channels and membrane proteins.

Interaction of Pseudomonas aeruginosa Exotoxin A with the human Sec61 complex suppresses passive calcium efflux from the endoplasmic reticulum

According to live-cell calcium-imaging experiments, the Sec61 complex is a passive calcium-leak channel in the human endoplasmic reticulum (ER) membrane that is regulated by ER luminal immunoglobulin heavy chain binding protein (BiP) and cytosolic Ca2+-calmodulin. In single channel measurements, the open Sec61 complex is Ca2+ permeable. It can be closed not only by interaction with BiP or Ca2+-calmodulin, but also with Pseudomonas aeruginosa Exotoxin A which can enter human cells by retrograde transport. Exotoxin A has been shown to interact with the Sec61 complex and, thereby, inhibit ER export of immunogenic peptides into the cytosol. Here, we show that Exotoxin A also inhibits passive Ca2+ leakage from the ER in human cells, and we characterized the N-terminus of the Sec61 α-subunit as the relevant binding site for Exotoxin A.

Validation of Replay-Based Underwater Acoustic Communication Channel Simulation

This paper discusses validation methods for underwater acoustic communication channel simulators, and validates direct and stochastic replay of underwater acoustic communication channels as implemented in a channel simulator called Mime. Direct replay filters an input signal directly with a measured time-varying impulse response, whereas stochastic replay filters an input signal with a synthetic impulse response consistent with the scattering function of the measured channel. The validation uses data from two sea experiments and a diverse selection of communication schemes. Good agreement is found between bit error rates and packet error rates of in situ transmissions and simulated transmissions. Long-term error statistics of in situ signaling are also reproduced in simulation when a single channel measurement is used to configure the simulator. In all except one comparison, the packet error rate in simulation is within 20% of the packet error rate measured on location. The implication is that this type of channel simulator can be employed to test new modulation schemes in a realistic fashion without going to sea, except for the initial data collection.

Real-Time Monitoring of Lycopene Content in Tomato-Derived Products during Processing: Implementation of a Novel Double-Slit Raman Spectrometer

Lycopene is a very attractive antioxidant associated with cancer prevention in humans. Therefore, it is important to develop new analytical methods that allow for differentiation of food production streams that contain various antioxidant concentrations. The lycopene content in tomato juice, an intermediate between raw tomatoes and the final tomato paste product, was monitored on-line for 46 days at a production plant with a novel, patented double-channel Raman setup. The setup comprises a double-channel mini spectrometer placed in a fixed optical setup, and for each measurement there are two slightly shifted Raman spectra on the x-axis that opens up for additional data processing. The prototype was constructed specifically for 532 nm excitation with no moving parts, and it was designed to optimize each part for the rest of the system. That was the first step toward an integrated optical in-line process analytical solution for industry. As proof of concept, the developed prototype was able to perform a real-time differentiation of the normal and medium to high lycopene content in tomato juice. A correlation factor for double-channel measurements was compared with a correlation factor for background-corrected single-channel measurements by correlating with high performance liquid chromatography reference measurements (1-20 mg of lycopene per 100 g of wet sample). The latter gave a slightly better correlation for the specific application (R(2) = 0.76), acceptable for proof of concept. Real-time information is extremely valuable for the tomato processing plant, mainly because it can be used for improved differentiation of high lycopene content tomato paste to ensure a higher product price. In addition, the developed process analytical technology solution allows for differentiated payment of the tomato farmers based on the lycopene content in their crops.

Enhanced Empirical Mode DecompositionApproach toEliminateMotion Artifacts in EEG using ICA and DWT

To ease the concept of diagnosing human health a strong and viable biomedical signal is of importance. Biomedical signal measurement and processing of signal cause the probability of artifacts which can obstruct the features of interest and quality of information available in the signal. So elimination of artifacts from physiological signals is an essential step. The single channel measurement is important when instrumentation complexity is needed to be minimized, in spite of many multichannel signals recording methods available.In this paper, an enhanced empirical approach to remove the artifacts of single channel signal is described followed by filtering mechanism using ICA and DWT. The input EEG is a single channel and is converted into multichannel for ICA operations. The multi-channel EEG signal is filtered with fast ICA algorithmand DWT is employed to reject any traces of artifacts left in the signal. This technique is tested against currently available wavelet de-noising and EMD-ICA technique using functional near infrared spectroscopy (EEG) signal. Artifact removal technique has been evaluated by DSNR, Lambda (λ), Autocorrelation and PSD. The results pronounce the eligibility of proposed algorithm to stand on top of currently deployed algorithms with 12% improvement in DSNR and alsoa significant improvement in different parameters too.

Cardiac hypertrophy associated with impaired regulation of cardiac ryanodine receptor by calmodulin and S100A1

The cardiac ryanodine receptor (RyR2) is inhibited by calmodulin (CaM) and S100A1. Simultaneous substitution of three amino acid residues (W3587A, L3591D, F3603A; RyR2ADA) in the CaM binding domain of RyR2 results in loss of CaM inhibition at submicromolar (diastolic) and micromolar (systolic) Ca²⁺, cardiac hypertrophy, and heart failure in Ryr2ADA/ADA mice. To address whether cardiac hypertrophy results from the elimination of CaM and S100A1 inhibition at diastolic or systolic Ca²⁺, a mutant mouse was generated with a single RyR2 amino acid substitution (L3591D; RyR2D). Here we report that in single-channel measurements RyR2-L3591D isolated from Ryr2D/D hearts lost CaM inhibition at diastolic Ca²⁺ only, whereas S100A1 regulation was eliminated at both diastolic and systolic Ca²⁺. In contrast to the ~2-wk life span of Ryr2ADA/ADA mice, Ryr2D/D mice lived longer than 1 yr. Six-month-old Ryr2D/D mice showed a 9% increase in heart weight-to-body weight ratio, modest changes in cardiac morphology, and a twofold increase in atrial natriuretic peptide mRNA levels compared with wild type. After 4-wk pressure overload with transverse aortic constriction, heart weight-to-body weight ratio and atrial natriuretic peptide mRNA levels increased and echocardiography showed changes in heart morphology of Ryr2D/D mice compared with sham-operated mice. Collectively, the findings indicate that the single RyR2-L3591D mutation, which distinguishes the effects of diastolic and systolic Ca²⁺, alters heart size and cardiac function to a lesser extent in Ryr2D/D mice than the triple mutation in Ryr2ADA/ADA mice. They further suggest that CaM inhibition of RyR2 at systolic Ca²⁺ is important for maintaining normal cardiac function.

AtALMT9 is a malate-activated vacuolar chloride channel required for stomatal opening in Arabidopsis

Water deficit strongly affects crop productivity. Plants control water loss and CO2 uptake by regulating the aperture of the stomatal pores within the leaf epidermis. Stomata aperture is regulated by the two guard cells forming the pore and changing their size in response to ion uptake and release. While our knowledge about potassium and chloride fluxes across the plasma membrane of guard cells is advanced, little is known about fluxes across the vacuolar membrane. Here we present the molecular identification of the long-sought-after vacuolar chloride channel. AtALMT9 is a chloride channel activated by physiological concentrations of cytosolic malate. Single-channel measurements demonstrate that this activation is due to a malate-dependent increase in the channel open probability. Arabidopsis thaliana atalmt9 knockout mutants exhibited impaired stomatal opening and wilt more slowly than the wild type. Our findings show that AtALMT9 is a vacuolar chloride channel having a major role in controlling stomata aperture.