On Some Discrete Distributions and their Applications with Real Life Data

This article reviews some useful discrete models and compares their performance in terms of the high frequency of zeroes, which is observed in many discrete data (e.g., motor crash, earthquake, strike data, etc.). A simulation study is conducted to determine how commonly used discrete models (such as the binomial, Poisson, negative binomial, zero-inflated and zero-truncated models) behave if excess zeroes are present in the data. Results indicate that the negative binomial model and the ZIP model are better able to capture the effect of excess zeroes. Some real-life environmental data are used to illustrate the performance of the proposed models

Testing the Population Coefficient of Variation

The coefficient of variation (CV), which is used in many scientific areas, measures the variability of a population relative to its mean and standard deviation. Several methods exist for testing the population CV. This article compares a proposed bootstrap method to existing methods. A simulation study was conducted under both symmetric and skewed distributions to compare the performance of test statistics with respect to empirical size and power. Results indicate that some of the proposed methods are useful and can be recommended to practitioners

Some Ridge Regression Estimators and Their Performances

The estimation of ridge parameter is an important problem in the ridge regression method, which is widely used to solve multicollinearity problem. A comprehensive study on 28 different available estimators and five proposed ridge estimators, KB1, KB2, KB3, KB4, and KB5, is provided. A simulation study was conducted and selected estimators were compared. Some of selected ridge estimators performed well compared to the ordinary least square (OLS) estimator and some existing popular ridge estimators. One of the proposed estimators, KB3, performed the best. Numerical examples were given

A Simulation Study on the Size and Power Properties of Some Ridge Regression Tests

Ridge regression techniques have been extensively used to solve the multicollinearity problem for both linear and non-linear regression models since its inception. This paper studied different ridge regression t-type tests of the individual coefficients of a linear regression model. A simulation study has been conducted to evaluate the performance of the proposed tests with respect to their sizes and powers under different settings of the linear regression model. Our simulation results demonstrated that most of the proposed tests have sizes close to the 5% nominal level and all tests except tAKS, tkM2 and tkM9 have considerable gain in powers over the ordinary OLS t-type test. It is also observed that some of the proposed test statistics are performing better than the HK and HKB tests which are proposed some authors

A rare case of isoniazid induced sideroblastic anemia

Sideroblastic anemia is a rare cause of anemia. Most of it accounts for the genetic cause, while drug induced is still uncommon. Our patient, a 20 year old female, is a known case of right frontal tuberculoma on ATT presented with complaints of generalized weakness and loss of appetite. On evaluation, she was found to have severe anemia and bone marrow studies confirmed it to be sideroblastic anemia. On revisiting the history, it was noted that she was not taking pyridoxine supplements as advised along with antitubercular drugs. Our patient is one among the few documented cases of Isoniazid induced sideroblastic anemia.This case needs attention because it is a preventable cause of anemia and the clinicians need to be aware about the compliance of the patient with the supplementary drugs.

Hamstring versus peroneus longus autograft for arthroscopic anterior cruciate ligament reconstruction – which is better for Indian population?

Background: Hamstring autograft has been a popular option for anterior cruciate ligament (ACL) reconstruction. Of late, the use of peroneus longus tendon has shown promising results. Indian population is predominantly kneeling population where squatting and sitting crossed are associated with daily living activities. This study involves the comparative analysis of the morbidities associated with both the grafts and the choice of autograft based on the Indian population needs. Methods: A comparative cohort study was conducted on 60 patients who underwent ACL reconstruction during 2022-2023.The patients were randomly assigned for either peroneus longus or hamstring autograft. After a follow-up of one year, the donor site morbidities were assessed using Lysholm score for knee and foot and ankle disability index (FADI) for ankle joint. Results: A significant statistical difference (p value ≤0.001) was seen in the mean time required to harvest hamstring and peroneal grafts. Although the Lysholm scores were statistically insignificant (p=0.03) in both the groups, 20% of patients with hamstring graft, recorded VAS pain score >7/10 while deep squatting and loading heavy weights. FADI scores of the donor side and contralateral side in patients with peroneal graft showed statistically insignificant results (p value=0.06). Conclusions: Owing to the graft diameter, robust quality, tensile strength and lesser knee joint morbidity, peroneus longus can be considered as a better alternative autograft to the Indian population. However, in athletes, a careful decision should be made as further long-term studies are required to assess the ankle joint morbidity due to this autograft

Estimating the Population Standard Deviation with Confidence Interval: A Simulation Study under Skewed and Symmetric Conditions

This paper investigates the performance of ten methods for constructing a confidence interval estimator for the population standard deviation by a simulation study. Since a theoretical comparison among the interval estimators is not possible, a simulation study has been conducted to compare the performance of the selected interval estimators. Data were randomly generated from several distributions with a range of sample sizes. Various evaluation criterions are considered for performance comparison. Two health related data have been analyzed to illustrate the application of the proposed confidence intervals. Based on simulation results, some intervals with the best performance have been recommended for practitioners

Sequencing of Pax6 loci from the elephant shark reveals a family of Pax6 genes in vertebrate genomes, forged by ancient duplications and divergences

Pax6 is a developmental control gene essential for eye development throughout the animal kingdom. In addition, Pax6 plays key roles in other parts of the CNS, olfactory system, and pancreas. In mammals a single Pax6 gene encoding multiple isoforms delivers these pleiotropic functions. Here we provide evidence that the genomes of many other vertebrate species contain multiple Pax6 loci. We sequenced Pax6-containing BACs from the cartilaginous elephant shark (Callorhinchus milii) and found two distinct Pax6 loci. Pax6.1 is highly similar to mammalian Pax6, while Pax6.2 encodes a paired-less Pax6. Using synteny relationships, we identify homologs of this novel paired-less Pax6.2 gene in lizard and in frog, as well as in zebrafish and in other teleosts. In zebrafish two full-length Pax6 duplicates were known previously, originating from the fish-specific genome duplication (FSGD) and expressed in divergent patterns due to paralog-specific loss of cis-elements. We show that teleosts other than zebrafish also maintain duplicate full-length Pax6 loci, but differences in gene and regulatory domain structure suggest that these Pax6 paralogs originate from a more ancient duplication event and are hence renamed as Pax6.3. Sequence comparisons between mammalian and elephant shark Pax6.1 loci highlight the presence of short- and long-range conserved noncoding elements (CNEs). Functional analysis demonstrates the ancient role of long-range enhancers for Pax6 transcription. We show that the paired-less Pax6.2 ortholog in zebrafish is expressed specifically in the developing retina. Transgenic analysis of elephant shark and zebrafish Pax6.2 CNEs with homology to the mouse NRE/Pα internal promoter revealed highly specific retinal expression. Finally, morpholino depletion of zebrafish Pax6.2 resulted in a "small eye" phenotype, supporting a role in retinal development. In summary, our study reveals that the pleiotropic functions of Pax6 in vertebrates are served by a divergent family of Pax6 genes, forged by ancient duplication events and by independent, lineage-specific gene losses

24 Hours chronomics of ambulatory blood pressure and its relation with circadian rhythm of 6-sulfatoxy melatonin in night shift health care workers

Background: Night shift workers have altered circadian pattern of blood pressure/heart rate and hormones like melatonin and cortisol. Due to this variation, night shift worker suffers from various cardiovascular disorders and hormonal disturbances.Methods: The Present study was aimed to investigate the effects of rotating night shift on 24 hours chronomics of BP/HR and its relation with 6-sulfatoxy melatonin levels. 62 healthy nursing professionals, aged 20-40 year, performing day and night shift duties were recruited. Each month scheduled to continuous 9 days night shift (12 hours in regular 9 nights, from 20:00 to 08:00); after 9 days night shift they perform remaining duties in day shift and 4 days off in each month.Results: Ambulatory BP and HR were recorded at every 30 min intervals in day time and each hour in night time synchronically with circadian pattern of 6 sulfatoxy melatonin during shift duties. Highly Significant difference was found in double amplitude (2DA) of blood pressure between night and day shift (p<0.001). In night shift, hyperbaric index (HBI) of mean systolic blood pressure was found to be increased at 00-03 am (midnight) while during day shift, peak was found at 06-09 am. Peak melatonin was to be found in early morning as compared to mid night in both the shift.Conclusions: The present study concluded that the desynchronization was appeared during night shift and entrainment of circadian rhythm in the day shift.