A NEW METHOD OF ROBUST LINEAR REGRESSION ANALYSIS: SOME MONTE CARLO EXPERIMENTS

This paper has elaborated upon the deleterious effects of outliers and corruption of dataset on estimation of linear regression coefficients by the Ordinary Least Squares method. Motivated to ameliorate the estimation procedure, it introduces the robust regression estimators based on Campbell's robust covariance estimation method. It investigates into two possibilities: first, when the weights are obtained strictly as suggested by Campbell and secondly, when weights are assigned in view of the Hampel's median absolute deviation measure of dispersion. Both types of weights are obtained iteratively and using those weights, two different types of weighted least squares procedures have been proposed. These procedures are applied to detect outliers in and estimate regression coefficients from some widely used datasets such as stackloss, water salinity, Hawkins- Bradu-Kass, Hertzsprung-Russell Star and pilot-point datasets. It has been observed that Campbell-II in particular detects the outlier data points quite well. Subsequently, some Monte Carlo experiments have been carried out to assess the properties of these estimators whose findings indicate that for larger number and size of outliers, the Campbell-II procedure outperforms the Campbell-I procedure. Unless perturbations introduced to the dataset are numerous and very large in magnitude, the estimated coefficients are also nearly unbiased.Robust regression, Campbell's robust covariance, outliers, Monte Carlo Experiment, Median absolute Deviation

ROBUST TWO�STAGE LEAST SQUARES: SOME MONTE CARLO EXPERIMENTS

The Two�Stage Least Squares (2�SLS) is a well known econometric technique used to estimate the parameters of a multi�equation econometric model when errors across the equations are not correlated and the equation(s) concerned is (are) over�identified or exactly identified. However, in presence of outliers in the data matrix, the classical 2�SLS has a very poor performance. In this study a method has been proposed to generalize the 2�SLS to the Weighted Two�Stage Least Squares (W2�SLS), which is robust to the effects of outliers and perturbations. Monte Carlo experiments have been conducted to demonstrate the performance of the proposed method. It has been found that robustness of the proposed method is not much destabilized by the magnitude of outliers. The breakdown point of the method is quite high, somewhere between 45 to 50 percent of the number of points in the data matrix.Two�Stage Least Squares, multi�equation econometric model, simultaneous equations, outliers, robust, weighted least squares, Monte Carlo experiments, unbiasedness, efficiency, breakdown point, perturbation, structural parameters, reduced form

An effective method for extraction and polymerase chain reaction (PCR) amplification of DNA from formalin preserved tissue samples of snow leopard

Formalin-preserved biological samples obtained from endangered species are valuable in assessing genetic diversity. To make use of snow leopard samples preserved in formalin over a period of two to seven years, we optimized the method of extracting DNA from these samples. We used (a) phenol chloroform : isoamyl alcohol, (b) the Qiagen DNeasy Blood and Tissue Kit (Qiagen, Germany), (c) the Qiagen DNeasy Blood and Tissue Kit after treating the samples with NaOH for three days and (d) the Qiagen DNeasy Blood and Tissue Kit after treating the samples with phosphate buffered saline (PBS) for three days. The usefulness of the extracted DNA was assessed on the basis of mitochondrial (150 to 550 bp) and nuclear (95 to 229 bp) markers. There was no PCR amplification with the first two methods. The PCR amplification with the NaOH and PBS treatment had a success rate of 30 to 100% for both mitochondrial and nuclear markers. The PBS method is the best method for extraction of DNA from formalin-preserved samples of longer period (two to seven years) because of higher success rate in amplifying mitochondrial gene of ca. 550 bp (60%) than the NaOH method (28%). The overall amplification of microsatellite markers in such samples was also higher in samples treated with PBS (43 to 100%) than NaOH (0 to 100%). The PCR products obtained were confirmed through DNA sequencing to be of snow leopard origin. The optimized protocol will enable genetic studies to be conducted on tissue samples of other species that have been preserved in formalin. The protocol will be particularly useful for species that are elusive and from which it is difficult to collect fresh tissue samples.Keywords: Formalin, polymerase chain reaction (PCR), mtDNA, microsatellites, snow leopardAfrican Journal of Biotechnology Vol. 12(22), pp. 3399-340

Impact of sleep disturbances and autonomic dysfunction on the quality of life of patients with fibromyalgia

Objectives: Fibromyalgia, a painful musculoskeletal disorder is associated with sleep disturbances as well as autonomic dysfunction. Pathophysiology of fibromyalgia is yet not clear and neuroanatomical proximity of sleep and autonomic centre prompts probable involvement of the two impacting the quality of life of fibromyalgia patients. Present study was done with the objective to explore the extent of sleep disturbances and/or autonomic dysfunction in fibromyalgia and asses their impact on quality of life of fibromyalgia patients. Method and materials: Thirty consecutive fibromyalgia patients (diagnosed by ACR 2010) from out-patient department and 30 age-gender matched controls were enrolled after the ethical clearance. All participants were evaluated for: (1) sleep using Pittsburgh sleep quality index and medical outcomes study sleep scale-12 Revised, (2) Quality of life by 36 item short-form health survey-36v2TM and revised fibromyalgia impact questionnaire (only patients). Autonomic functions of patients were evaluated by standard cardiovascular autonomic function tests by Ewing’s battery and heart rate variability (5-min) measurement. Results: Fibromyalgia patients had increased sleep disturbances compared to controls (39.46 ± 11, 59.61 ± 2.31; p=0.0001) and very poor sleep quality (13.63 ± 4.15, 3.03 ± 1.56; p=0.0001) as well as quality of life (p=0.0001) which further deteriorated with increasing severity of fibromyalgia. Twelve patients had autonomic dysfunction but it was neither associated with sleep disturbances nor with quality of life. Conclusions: Mild to moderate grade fibromyalgia patients have significant sleep disturbance, poor sleep quality which remarkably impacts their quality of life. Autonomic dysfunction is not an early feature of disease. The study suggests that full spectrum of sleep disturbances and sleep quality should be explored in fibromyalgia syndrome (FMS) patients

Technology Pipeline for Large Scale Cross-Lingual Dubbing of Lecture Videos into Multiple Indian Languages

Cross-lingual dubbing of lecture videos requires the transcription of the original audio, correction and removal of disfluencies, domain term discovery, text-to-text translation into the target language, chunking of text using target language rhythm, text-to-speech synthesis followed by isochronous lipsyncing to the original video. This task becomes challenging when the source and target languages belong to different language families, resulting in differences in generated audio duration. This is further compounded by the original speaker's rhythm, especially for extempore speech. This paper describes the challenges in regenerating English lecture videos in Indian languages semi-automatically. A prototype is developed for dubbing lectures into 9 Indian languages. A mean-opinion-score (MOS) is obtained for two languages, Hindi and Tamil, on two different courses. The output video is compared with the original video in terms of MOS (1-5) and lip synchronisation with scores of 4.09 and 3.74, respectively. The human effort also reduces by 75%

Tigers of Sundarbans in India: Is the Population a Separate Conservation Unit?

The Sundarbans tiger inhabits a unique mangrove habitat and are morphologically distinct from the recognized tiger subspecies in terms of skull morphometrics and body size. Thus, there is an urgent need to assess their ecological and genetic distinctiveness and determine if Sundarbans tigers should be defined and managed as separate conservation unit. We utilized nine microsatellites and 3 kb from four mitochondrial DNA (mtDNA) genes to estimate genetic variability, population structure, demographic parameters and visualize historic and contemporary connectivity among tiger populations from Sundarbans and mainland India. We also evaluated the traits that determine exchangeability or adaptive differences among tiger populations. Data from both markers suggest that Sundarbans tiger is not a separate tiger subspecies and should be regarded as Bengal tiger (P. t. tigris) subspecies. Maximum likelihood phylogenetic analyses of the mtDNA data revealed reciprocal monophyly. Genetic differentiation was found stronger for mtDNA than nuclear DNA. Microsatellite markers indicated low genetic variation in Sundarbans tigers (He= 0.58) as compared to other mainland populations, such as northern and Peninsular (Hebetween 0.67- 0.70). Molecular data supports migration between mainland and Sundarbans populations until very recent times. We attribute this reduction in gene flow to accelerated fragmentation and habitat alteration in the landscape over the past few centuries. Demographic analyses suggest that Sundarbans tigers have diverged recently from peninsular tiger population within last 2000 years. Sundarbans tigers are the most divergent group of Bengal tigers, and ecologically non-exchangeable with other tiger populations, and thus should be managed as a separate "evolutionarily significant unit" (ESU) following the adaptive evolutionary conservation (AEC) concept.Wildlife Institute of India, Dehra Dun (India)

Methylcobalamine (Vitamin B12): Water Soluble Vitamin with Various Pharmacological Aspect

Vitamin B12 is a water-soluble vitamin that plays a key role in the brain's proper functioning and nervous system, in blood flow, and in reducing weakness and tiredness. In their food, most people get adequate vitamin B12, but in some health conditions (e.g. inadequate sleep, stomach/intestinal disorders, inflammation, cancer), there could be a shortage. If left unchecked, severe Vitamin B12 deficiency results in anemia and nerve damage. Vitamin B12 deficiency is typically treated using parenteral and oral dosage formulations, but absorption and compliance problems are involved with these routes of administration. Most significantly, the function of this missing intrinsic factor has been shown to assist in vitamin B12 absorption and a deficiency known as pernicious anaemia. Vitamin B12 is only partially absorbed when delivered by mouth to patients with pernicious anemia, but hematologically re-absorbed in patients with pernicious anemia. Parenteral administration of the extrinsic element will treat pernicious anaemia satisfactorily. There are several roles and advantages of vitamin B 12 in the human body with therapeutic effects also. Keywords: Water Soluble Vitamins, Methylcobalamine, Vitamin B12, Pernicious Anaemia

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Post-Covid Era: Predictive Aspect of Psychological Condition Due to Sudden Pandemic

Covid-19 has impacted the lives of people in various aspects positive as well as negative. It has an impact on different areas of life, including the economy, industries, global markets, agriculture, human health, etc. The virus caused disruptions to daily life and restrictions on activities in many communities during its multiple outbreaks. Hope for a potential end to the pandemic emerged with the stepping up of vaccination campaigns. However, the continual appearance of mutant strains and vaccine hesitancy has been problems both nationally and internationally. People's normal activities, routines, and livelihoods have been disrupted by self-isolation and quarantine, potentially leading to an increase in loneliness, anxiety, depression, insomnia, excessive alcohol and drug use, and self-harm or suicidal activity. The psychological aspects of the post-covid-19 era are the effect of covid-19 on CNS, and physiological and psychological diseases caused due to covid-19. The article explains Post Trauma Stress Disorder as a psychological scar, Social evils arising due to covid-19, and predictive reasons for the increase in mental illness Keywords- Covid-19, Pandemic, Mental Health, Post Trauma Stress Disorder,  Depression, Anxiet