EEG-based source localization with enhanced virtual aperture using second order statistics.

For the past few decades source localization, based on EEG modality, has been a very active area of research. EEG signal provides temporal resolution in millisecond range that can capture rapidly changing patterns of brain activity but it has a low spatial resolution as compared to techniques like fMRI, PET, CT scan, etc. So, one of the motives of this research is to improve the spatial resolution of the EEG signal. Many successful attempts have been made to localise the active neural sources using EEG signals with the introduction of techniques like MNE, LORETA, sLORETA, FOCUSS, etc. But these techniques require a large number of electrodes for correct localization of a few sources. This paper aims at providing a new method for the localization of EEG sources with a fewer electrode. This is achieved by exploiting the second-order statistics to enhance the aperture and solve the EEG localization problem. The comparison of the proposed method with the state-of-the-art methods is done by observing the localization error with variation in SNR, number of snapshots (time samples), number of active sources, and number of electrodes. The results show that the proposed method can detect a greater number of sources with fewer electrodes and with higher accuracy as compared to methods available in the literature. Real -time EEG signal during an arithmetic task is considered and the proposed algorithm clearly shows a sparse activity in the frontal region.

Independent Detection of T-Waves in Single Lead ECG Signal Using Continuous Wavelet Transform.

INTRODUCTION: In the ECG signals, T-waves play a very important role in the detection of cardiac arrest. During myocardial ischemia, the first significant change occurs on the T-wave. These waves are generated due to the repolarization of the heart ventricle. The independent detection of T-waves is a bit challenging due to its variable nature, therefore, most of the algorithms available in the literature for T-wave detection use the detection of the QRS complex as the starting point. But accurate detection of Twave is very much required, as clinically, the first indication of a shortage of blood supply to the heart muscle (myocardial ischemia) shows up as changes in T-wave followed by other changes in the morphology of the ECG signal. MATERIALS AND METHODS: In this paper, an efficient and novel algorithm based on Continuous Wavelet Transform (CWT) is presented to detect the Twave independently. In CWT, for better matching, a new mother wavelet is designed using the pattern and shape of the Twave. This algorithm is validated on all the signals of the QT database. CONCLUSION: The algorithm attains an average sensitivity of 99.88% and positive predictivity of 99.81% for the signals annotated by the cardiologists in the database.

Capacity analysis of underwater visible light communication systems over a lossy channel in the presence of noises.

Absorption and scattering losses due to impurities and turbidity in the water affect the transmission quality of underwater visible light communication links, restricting the channel capacity. For the first time to our knowledge, this paper analytically studies the channel capacity of a point-to-point underwater visible light communication link in the presence of input-independent and -dependent noises along with absorption and scattering losses. This way, novel lower and upper bound expressions on channel capacity are derived when average and peak-intensity constraints are imposed on the channel input. Our proposed upper and lower bounds are tight at high optical signal-to-noise ratio. The derived analytic expression of capacity also helps to evaluate the available data rate in the presence of different types of noise and water. From the results, we can say that input-dependent noise causes more system capacity degradation than input-independent noise. The results show that good water quality is crucial for high-capacity communication links. Furthermore, it is shown that the attenuation of the optical signal is more in water when compared to air as a medium, and channel capacity decreases as the link range increases. The results reported in this paper provide valuable insight into the design of underwater visible light communication systems.

An unsupervised clustering-based scale-lag receiver design approach for the doubly selective underwater acoustic channel.

This paper details the architecture of a novel scale-lag rake receiver for the doubly selective underwater acoustic (UWA) channel. The shallow UWA channel is known to have a large Doppler spread. The cause of this is primarily due to the large spread of the angle of arrival of the received signal's paths. The Doppler scale value is dependent on the angle of arrival of the received signal. The Doppler spread is significant, and multiple Doppler scales are present in the UWA channel. Therefore, the receivers operating with only a single Doppler scale compensation perform sub-optimally. The optimal receiver should incorporate all possible Doppler scales for better performance. The receiver needs to have multiple sampling rates to incorporate all Doppler scales. It is usually done by having multiple receive channels, one for each sampling rate. It requires tremendous resources as its complexity increases exuberantly. This paper shows that these Doppler scales are clustered and that an optimal receiver is implemented using fewer receiver channels, each corresponding to one such cluster. It reduces the receiver's complexity. The simulation results demonstrate that using the Doppler scale value associated with the path of the highest magnitude per cluster yields the best performance.

Mitochondrial Stress-Mediated Targeting of Quiescent Cancer Stem Cells in Oral Squamous Cell Carcinoma.

INTRODUCTION: Despite improved therapeutics in oral squamous cell carcinoma (OSCC), tumor cells that are either quiescent and/or endowed with stem cell-like attributes usually survive treatment and recreate tumor load at relapse. Through this study, we aimed strategically to eliminate these stem cell-like cancer cells using a combination drug approach. METHODS: Primary cultures from 15 well-moderately differentiated OSCC were established, and the existence of cancer cells with stem cell-like characteristics using five cancer stem cell (CSC) specific markers - CD44, CD133, CD147, C166, SOX2 and spheroid assay was ascertained. Next, we assessed quiescence in CSCs under normal and growth factor-deprived conditions using Ki67. Among several gene signatures regulating quiescent cellular state, we evaluated the effect of inhibiting Dyrk1b in combination with topoisomerase II and histone deacetylase inhibitors in targeting quiescent CSCs. Multiple drug-effect analysis was carried out with CompuSyn software to determine combination-index values. RESULTS: We observed that CD44+CD133+ showed the highest level of SOX2 expression. CSCs showed varying degrees of quiescence, and inhibition of Dyrk1b decreased quiescence and sensitized CSCs to apoptosis. In the drug-combination study, Dyrk1b inhibitor was combined with topoisomerase II and histone deacetylase inhibitors to target quiescent CSCs. In combination, a synergistic effect was seen even at a 16-fold lower dose than IC50. Furthermore, combined treatment decreased glutathione levels and increased ROS and mitochondrial stress, leading to increased DNA damage and cytochrome c in CSCs. CONCLUSION: We report marker-based identification of CSC subpopulations and synergy of Dyrk1b inhibitor with topoisomerase II and HDAC inhibitors in primary OSCC. The results provide a new therapeutic strategy to minimize quiescence and target oral CSCs simultaneously.

Role of microbiological tests in diagnosis of genital tuberculosis of women with infertility: A view.

OBJECTIVE: India is a country sharing one fourth of the global incidence of tuberculosis. It is much easier to diagnose pulmonary cases, but challenges are with extrapulmonary cases. Genital tuberculosis is considered as an important cause of infertility in young females in India and difficult to diagnose. It requires incorporation of different modalities that should correctly, timely and rapidly diagnose the case. METHODS: This study was conducted retrospectively for a period of 12 months on 438 endometrial samples from females with history of infertility. Three modalities namely Ziehl-Neelsen staining, Automated liquid culture and Nucleic acid amplification technique (TB-PCR) were compared and their sensitivity in diagnosis of genital tuberculosis was ascertained. RESULTS: Out of 438 samples, 18 samples were found positive with at least one modality. TB-PCR positivity was 3.6% (16 cases) in comparison to culture where positivity was 1.59% (7 cases). Five samples were found culture and TB-PCR positive and only one sample was positive by all three diagnostic tests. CONCLUSION: Infertility in young female per se is usually heart breaking and distressing. Therefore, it is essential to diagnose and treat the cases of genital tuberculosis before irreversible damage of tube may happen. Although, advancement in diagnostic field is there from microscopy to molecular method, but still diagnosis of genital tuberculosis is challenging. Correct diagnosis prevents young female from mental trauma and toxicity of anti-tuberculosis drugs given on suspicion in high prevalence country like India.

Aiding the Detection of QRS Complex in ECG Signals by Detecting S Peaks Independently.

In this paper, a novel algorithm for the accurate detection of QRS complex by combining the independent detection of R and S peaks, using fusion algorithm is proposed. R peak detection has been extensively studied and is being used to detect the QRS complex. Whereas, S peaks, which is also part of QRS complex can be independently detected to aid the detection of QRS complex. In this paper, we suggest a method to first estimate S peak from raw ECG signal and then use them to aid the detection of QRS complex. The amplitude of S peak in ECG signal is relatively weak than corresponding R peak, which is traditionally used for the detection of QRS complex, therefore, an appropriate digital filter is designed to enhance the S peaks. These enhanced S peaks are then detected by adaptive thresholding. The algorithm is validated on all the signals of MIT-BIH arrhythmia database and noise stress database taken from physionet.org. The algorithm performs reasonably well even for the signals highly corrupted by noise. The algorithm performance is confirmed by sensitivity and positive predictivity of 99.99% and the detection accuracy of 99.98% for QRS complex detection. The number of false positives and false negatives resulted while analysis has been drastically reduced to 80 and 42 against the 98 and 84 the best results reported so far.

Importance of Ayu Pareeksha for the Management of Diseases.

The word Ayurveda comes from the Sanskrit root Ayu which means span of life. The purpose of examination of Ayu is to obtain knowledge regarding longevity, residual span of life in diseased person and rate of the mortality. The purpose of Dashavidha Pariksha is to obtain knowledge regarding Dosha Bala (Vyadhi Bala), Bala (Rogibala) and Ayu of the patient as described in Charak Samhita. Commonly Ayu and Vaya are regarded as synonyms but they are not similar terms. Hence, description of Vaya and Ayu is separately mentioned in Charaka as well as Sushruta Samhita. Description exclusively on Ayu Pareeksha described in Charaka VimanSthana, Charaka Chikitsasthana, Charaka Indriya Sthana and Charaka Shareer Sthana. In Indriya Sthana, Ayu Pariksha indicates the residual life-span of the diseased person and where as in Jaatisutriya Adhyaya in Shareer Sthana mentioned the characteristic properties of the child who is going to survive for longer period of time. In Sushruta Samhita, Ayu is classified into three broad headings namely Dhirghayu, Madhyamayu and Alpayu and explained the characteristic properties of all the three.

Comparative Study of GeneXpert with ZN Stain and Culture in Samples of Suspected Pulmonary Tuberculosis.

INTRODUCTION: Tuberculosis remains one of the deadliest communicable diseases. There are number of tests available for the diagnosis of tuberculosis but conventional microscopy has low sensitivity and culture although gold standard, but takes longer time for positivity. On the other side, Nucleic acid amplification techniques due to its rapidity and sensitivity not only help in early diagnosis and management of tuberculosis especially in patients with high clinical suspicion like immunocompromised patients, history of contact with active tuberculosis patient etc., but also curtail the transmission of the disease. AIM: To evaluate the sensitivity, specificity, positive predictive value and negative predictive value of Nucleic acid amplification assay (GeneXpert) using respiratory samples in patients with suspected pulmonary tuberculosis and compare with AFB smear microscopy (Ziehl Neelsen stain) and Acid Fast Bacilli (AFB) culture. MATERIALS AND METHODS: We retrospectively reviewed the respiratory samples of suspected pulmonary tuberculosis (including Bronchoalveolar lavage and sputum) of 170 patients from Jan 2015 to Nov 2015 for ZN stain, culture and GeneXpert (Xpert(®) MTB/Rif assay). The sensitivity, specificity, PPV and NPV of GeneXpert and ZN microscopy were calculated using Liquid culture of Mycobacterium tuberculosis as gold standard. RESULTS: A total of 170 patient samples were evaluated in final analysis. Of these, 14 samples were positive by all three methods used in our study. The overall sensitivity, specificity, PPV and NPV of GeneXpert were 86.8%, 93.1%, 78.5% and 96% respectively and for BAL sample, 81.4%, 93.4%, 73.3% and 95.7% respectively. The overall sensitivity and specificity of AFB smear microscopy were 22.2%, % and 78.5% respectively and for BAL sample 22.2% and 100% respectively. For AFB negative samples sensitivity and specificity were 79.1% and 93.1% respectively. CONCLUSION: GeneXpert has a higher sensitivity than AFB smear microscopy in respiratory samples. GeneXpert can be a useful tool for early diagnosis of patients with high clinical suspicion of pulmonary tuberculosis. Positive GeneXpert, but culture negative results should be read cautiously and be well correlated with clinical and treatment history of the patient. The other major advantage of Gene Xpert is that it simultaneously detects Rifampicin resistance and especially beneficial in patient with MDR and HIV associated tuberculosis and should be studied further.

Structural and kinetic studies on adenylosuccinate lyase from Mycobacterium smegmatis and Mycobacterium tuberculosis provide new insights on the catalytic residues of the enzyme.

Adenylosuccinate lyase (ASL), an enzyme involved in purine biosynthesis, has been recognized as a drug target against microbial infections. In the present study, ASL from Mycobacterium smegmatis (MsASL) and Mycobacterium tuberculosis (MtbASL) were cloned, purified and crystallized. The X-ray crystal structure of MsASL was determined at a resolution of 2.16 Å. It is the first report of an apo-ASL structure with a partially ordered active site C3 loop. Diffracting crystals of MtbASL could not be obtained and a model for its structure was derived using MsASL as a template. These structures suggest that His149 and either Lys285 or Ser279 of MsASL are the residues most likely to function as the catalytic acid and base, respectively. Most of the active site residues were found to be conserved, with the exception of Ser148 and Gly319 of MsASL. Ser148 is structurally equivalent to a threonine in most other ASLs. Gly319 is replaced by an arginine residue in most ASLs. The two enzymes were catalytically much less active compared to ASLs from other organisms. Arg319Gly substitution and reduced flexibility of the C3 loop might account for the low catalytic activity of mycobacterial ASLs. The low activity is consistent with the slow growth rate of Mycobacteria and their high GC containing genomes, as well as their dependence on other salvage pathways for the supply of purine nucleotides. STRUCTURED DIGITAL ABSTRACT: purB and purB bind by x-ray crystallography (View interaction).

Role of prescribers in the level of patient satisfaction: a study in public health care settings.

AIMS: To assess the level of patient satisfaction with the various aspects of interaction of the health provider with the patient such as communication, examination and information regarding prescription in the allopathic public health facilities of Lucknow district. SETTINGS AND DESIGN: Public health facilities of Lucknow district, India. INTRODUCTION: Satisfaction in service provision is increasingly being used as a measure of health system performance. The satisfaction with the service provider i.e., the prescriber is a vital component of the whole process of consultation and largely determines the compliance of the patient to the treatment prescribed. Apart from this, satisfaction also varies according to the sociodemographic characteristics of the beneficiaries. We have therefore tried to study these factors in the present study. MATERIALS AND METHODS: Multistage stratified random sampling was used to select the health facilities while the patients were selected by systematic random sampling for the interview. STATISTICAL ANALYSIS: Number and percentages, mean and χ(2) test. RESULTS: The overall satisfaction regarding the doctor patient communication and certain aspects of examination was highest for the residents (75.4%) followed by the super specialists (71.5%) and specialists (69.1%). CONCLUSIONS: The findings of the study will help us educate the prescribers about the various neglected areas of the consultation which will go a long way to develop a consistent relationship between the providers and the beneficiaries for the attainment of the "Health for All".

Assessment of prescription pattern at the public health facilities of Lucknow district.

OBJECTIVES: To study the prescription pattern at the different levels of public health facilities of Lucknow district and to assess the average cost of drugs prescribed. METHODS: Multi-stage stratified random sampling was done to select 1625 prescriptions of the patients attending the different level of public health facilities in Lucknow district, from August 2005 to September 2006, which was used for the development of study tools, collection of data and analysis. RESULTS: The important components of prescription viz. examination findings, weight of the child, follow up visit and the signatures of the prescribers were absent in the prescriptions at the primary level. Polypharmacy was common (3.1 ± 1.6 drugs per prescription). The prescription of drugs by generic name was low (27.1%). The prescriptions at the secondary level health facilities were incomplete with respect to mentioning the suffix/prefix of the drug, full name, dose, frequency and strength of the drugs, and directions specifying the route and duration of the treatment. The average cost of drugs/prescription/day in US$ (Mean, SD) was found to be the highest at the tertiary level (0.34, 0.43), which decreased significantly at the primary level health facilities. CONCLUSION: The pattern of prescription in terms of completeness and rationality was poor. There is an urgent need to improve the standards of drug prescription.