Identification of a new potential native Indian cattle breed by population differentiation based on microsatellite markers

India has a rich heritage of rearing cattle where farmers selected native cattle suitable to their local agro-ecological conditions for centuries. It is reflected in 50 indigenous breeds of cattle, besides many lesser known populations not explored so far. It is the need of the hour to characterize such populations to have prudent improvement and conservation options. Thus, present study was carried out to assess the genetic diversity and relationship between an unexplored local cattle population (Kathani) and four established cattle breeds of adjoining area (Gaolao, Kosali, Ongole and Motu) by using 20 FAO recommended microsatellite markers. High variability was recorded in the Kathani population with a total of 198 alleles that varied between 5 (ILSTS11, TGLA22, INRA05) and 17 (ILSTS34) with a mean of 9.9 ± 0.73. The average observed heterozygosity (Ho) was 0.658 ± 0.054. Heterozygote deficiency was not significant (F_IS = 0.029 ± 0.063) indicating random mating prevalent across this population. Mean estimates of observed number of alleles and heterozygosity over all the loci and five populations were 9.73 ± 0.421 and 0.617 ± 0.022, respectively. In the overall populations, the homozygote excess (F_IT) of 0.293 ± 0.032, was partly due to the homozygote excess within breeds (F_IS = 0.121 ± 0.025) and to a larger extent due to high (0.05 < F_ST < 0.15) genetic differentiation among them (F_ST = 0.195 ± 0.029). Substantial pairwise Nei's genetic distance and high population differentiation indicated towards separate genetic identity of Kathani cattle. The analysis of genetic structure based on Bayesian approach indicated that the most probable number of clusters is five confirming definitive genetic differentiation among all the popultions. Entire analysis showed that a significant amount of genetic variation is maintained in Kathani, a lesser known cattle population that is distinct from the recognized breeds in the proximity. As this autochthonous cattle plays role in the economic sustainability of a marginal and disadvantaged area, it is important to preserve and develop its breeding.

Allelic sequence variation in the Sub1A, Sub1B and Sub1C genes among diverse rice cultivars and its association with submergence tolerance

Erratic rainfall leading to flash flooding causes huge yield losses in lowland rice. The traditional varieties and landraces of rice possess variable levels of tolerance to submergence stress, but gene discovery and utilization of these resources has been limited to the Sub1A-1 allele from variety FR13A. Therefore, we analysed the allelic sequence variation in three Sub1 genes in a panel of 179 rice genotypes and its association with submergence tolerance. Population structure and diversity analysis based on a 36-plex genome wide genic-SNP assay grouped these genotypes into two major categories representing Indica and Japonica cultivar groups with further sub-groupings into Indica, Aus, Deepwater and Aromatic-Japonica cultivars. Targetted re-sequencing of the Sub1A, Sub1B and Sub1C genes identfied 7, 7 and 38 SNPs making 8, 9 and 67 SNP haplotypes, respectively. Haplotype networks and phylogenic analysis revealed evolution of Sub1B and Sub1A genes by tandem duplication and divergence of the ancestral Sub1C gene in that order. The alleles of Sub1 genes in tolerant reference variety FR13A seem to have evolved most recently. However, no consistent association could be found between the Sub1 allelic variation and submergence tolerance probably due to low minor allele frequencies and presence of exceptions to the known Sub1A-1 association in the genotype panel. We identified 18 cultivars with non-Sub1A-1 source of submergence tolerance which after further mapping and validation in bi-parental populations will be useful for development of superior flood tolerant rice cultivars.

Cost-Effective Home Mechanical Ventilation in Neurosurgery Patients: Case Series of Three Patients

Background  Neurological patients who are ventilator-dependent occupy scarce beds in the hospitals for prolonged periods of time. Most, if not all, can be discharged on home mechanical ventilation (HMV). However, due to lack of insurance and state support, it remains prohibitively expensive for the vast majority of those who require it most.

Materials and Methods  The authors discuss three patients admitted in the Department of Neurosurgery between January and August 2019, who were discharged on HMV after remaining on ventilator support for prolonged period in the hospital. Each patient was discharged with two units (one as standby) of AgVa home ventilator (AgVa Healthcare; New Delhi, India), one Ambu-bag, one pulse oximeter, and one backup power supply unit capable of supplying power to ventilator for a minimum of 24 hours. All the equipment were given free-of-cost through donations by hospital staffs and other donors. All patients were followed up telephonically from their homes and the incidence of complications, ventilator malfunction, and additional cost of HMV on the families were ascertained.

Observation and Results  Of the three patients, two were male and one female. Age ranged from 12 to 17 years. The duration of in-hospital ventilator support prior to discharge on HMV varied from 1 to 5 years. There was no insurance cover available for any of the patients with all expenses being “out of pocket.” The equipment cost Indian Rupees (INR) 115,700 (USD 1,615: two units of AgVa home ventilator costing INR 100,000 [USD 1,396], one Ambu-bag costing INR 1,100 [USD 15], one pulse oximeter costing INR 1,600 [USD 22], and one backup power supply unit costing INR 13,000 [USD 182]). Discharge on HMV was planned on specific request from patients’ families and informed consent was taken from all. All patients had tracheostomies. Mode of HMV was pressure support ventilation in all. Telephonic follow-up ranged from 1 to 7 months. The cost of disposables was INR 100 per month (USD 0.7) for all the patients. No complications occurred in any patient. There was no incidence of ventilator-associated pneumonia (VAP) or ventilator malfunction.

Conclusions  Availability of cost-effective indigenous ventilator like AgVa home has made HMV possible, even for poor patients with neurological diseases, and has the potential to improve quality of life, decrease VAP rates, and free up scarce ventilator beds in hospitals. Longer-term follow-up in larger number of patients will improve the data on safety and feasibility in developing countries like India.

Structure based designing of benzimidazole/benzoxazole derivatives as anti-leishmanial agents

Folates are essential biomolecules required to carry out many crucial processes in leishmania parasite. Dihydrofolate reductase-thymidylate synthase (DHFR-TS) and pteridine reductase 1 (PTR1) involved in folate biosynthesis in leishmania have been established as suitable targets for development of chemotherapy against leishmaniasis. In the present study, various computational tools such as homology modelling, pharmacophore modelling, docking, molecular dynamics and molecular mechanics have been employed to design dual DHFR-TS and PTR1 inhibitors. Two designed molecules, i.e. 2-(4-((4-nitrobenzyl)oxy)phenyl)-1H-benzo[d]imidazole and 2-(4-((2,4-dichlorobenzyl)oxy)phenyl)-1H-benzo[d]oxazolemolecules were synthesized. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay was performed to evaluate in vitro activity of molecules against promastigote form of Leishmania donovani using Miltefosine as standard. 2-(4-((4-nitrobenzyl)oxy)phenyl)-1H-benzo[d]imidazole and 2-(4-((2,4-dichlorobenzyl)oxy)phenyl)-1H-benzo[d]oxazolemolecules were found to be moderately active with showed IC₅₀ = 68 ± 2.8 µM and 57 ± 4.2 µM, respectively.

Structural and biochemical studies of phosphopantetheine adenylyltransferase from Acinetobacter baumannii with dephospho-coenzyme A and coenzyme A

Phosphopantetheine adenylyl transferase catalyzes a rate limiting penultimate step of the multistep reaction which produces coenzyme A (CoA) as a final product. CoA is required as an essential cofactor in a number of metabolic reactions. Therefore inhibiting the function of this enzyme will lead to cell death in bacteria. Acinetobacter baumannii is multi drug resistant pathogen and causes infections in immunocompromised patients. AbPPAT has been cloned, expressed, purified and crystallized and structures of two complexes of AbPPAT with dephospho coenzyme A (dPCoA) and coenzyme A (CoA) have been determined. Both dPCoA and CoA molecules are observed in the substrate binding site of AbPPAT. A comparison with the structures of the complexes of PPAT from other species shows that the orientations of dPCoA are identical in all the structures. On the other hand, as observed from the structures of the complexes of CoA with PPAT, the orientations of CoA are found to differ considerably. This shows that the substrates occupy identical positions in the substrate binding sites of enzymes whereas the positions of inhibitors may differ. The binding studies carried out using fluorescence method and surface plasmon resonance techniques showed that binding affinity of CoA towards AbPPAT is nearly three times higher than that of dPCoA.

Tracking the adoption of bread wheat varieties in Afghanistan using DNA fingerprinting

BACKGROUND

Wheat is the most important staple crop in Afghanistan and accounts for the main part of cereal production. However, wheat production has been unstable during the last decades and the country depends on seed imports. Wheat research in Afghanistan has emphasized releases of new, high-yielding and disease resistant varieties but rates of adoption of improved varieties are uncertain. We applied DNA fingerprinting to assess wheat varieties grown in farmers' fields in four Afghan provinces.

RESULTS

Of 560 samples collected from farmers' fields during the 2015-16 cropping season, 74% were identified as varieties released after 2000, which was more than the number reported by farmers and indicates the general prevalence of use of improved varieties, albeit unknowingly. At the same time, we found that local varieties and landraces have been replaced and were grown by 4% fewer farmers than previously reported. In 309 cases (58.5%), farmers correctly identified the variety they were growing, while in 219 cases (41.5%) farmers did not. We also established a reference library of released varieties, elite breeding lines, and Afghan landraces, which confirms the greater genetic diversity of the landraces and their potential importance as a genetic resource.

CONCLUSIONS

Our study is the first in wheat to apply DNA fingerprinting at scale for an accurate assessment of wheat varietal adoption and our findings point up the importance of DNA fingerprinting for accuracy in varietal adoption studies.

Pain during Injection of Propofol: The Effect of Prior Administration of Ephedrine

Propofol causes pain on intravenous injection in 28 to 90% of patients. A number of techniques have been tried to minimize propofol-induced pain, with variable results. In a randomized, double-blind, placebo-controlled trial, we compared the efficacy of ephedrine 30 μg/kg pretreatment to lignocaine 40 mg for prevention of propofol-induced pain. Ninety-three adult patients, ASA 1 and 2, undergoing elective laparoscopic cholecystectomy were randomly assigned to three groups of 31 each. Group 1 received normal saline, group 2 received lignocaine 2% (40 mg) and group 3 received 30 μg/kg ephedrine. All pretreatment drugs were made up to 2 ml. Pain at the time of propofol injection was assessed on a four-point scale: 0=no pain, 1=mild pain, 2=moderate pain, and 3=severe pain. Twenty-seven patients (87%) of ephedrine pretreatment patients had pain during intravenous injection of propofol as compared to 24 (77%) in the normal saline group. In the lignocaine group, propofol-induced pain was observed in only 13 (42%) when compared with other study groups (P<0.05). Pretreatment with ephedrine 30 μg/kg did not attenuate pain associated with intravenous injection of propofol, nor did it improve haemodynamic stability during induction. However, pretreatment with 2% lignocaine (40 mg) was effective in attenuating propofol-associated pain.

Laser Acceleration of Highly Energetic Carbon Ions Using a Double-Layer Target Composed of Slightly Underdense Plasma and Ultrathin Foil

We report the experimental generation of highly energetic carbon ions up to 48 MeV per nucleon by shooting double-layer targets composed of well-controlled slightly underdense plasma and ultrathin foils with ultraintense femtosecond laser pulses. Particle-in-cell simulations reveal that carbon ions are ejected from the ultrathin foils due to radiation pressure and then accelerated in an enhanced sheath field established by the superponderomotive electron flow. Such a cascaded acceleration is especially suited for heavy ion acceleration with femtosecond laser pulses. The breakthrough of heavy ion energy up to many tens of MeV/u at a high repetition rate would be able to trigger significant advances in nuclear physics, high energy density physics, and medical physics.

Response Surface Methodology-Genetic Algorithm Based Medium Optimization, Purification, and Characterization of Cholesterol Oxidase from Streptomyces rimosus

The applicability of the statistical tools coupled with artificial intelligence techniques was tested to optimize the critical medium components for the production of extracellular cholesterol oxidase (COD; an enzyme of commercial interest) from Streptomyces rimosus MTCC 10792. The initial medium component screening was performed using Placket-Burman design with yeast extract, dextrose, starch and ammonium carbonate as significant factors. Response surface methodology (RSM) was attempted to develop a statistical model with a significant coefficient of determination (R² = 0.89847), followed by model optimization using Genetic Algorithm (GA). RSM-GA based optimization approach predicted that the combination of yeast extract, dextrose, starch and ammonium carbonate at concentrations 0.99, 0.8, 0.1, and 0.05 g/100 ml respectively, has resulted in 3.6 folds increase in COD production (5.41 U/ml) in comparison with the un-optimized medium (1.5 U/ml). COD was purified 10.34 folds having specific activity of 12.37 U/mg with molecular mass of 54 kDa. The enzyme was stable at pH 7.0 and 40 °C temperature. The apparent Michaelis constant (K_m) and V_max values of COD were 0.043 mM and 2.21 μmol/min/mg, respectively. This is the first communication reporting RSM-GA based medium optimization, purification and characterization of COD by S. rimosus isolated from the forest soil of eastern India.

Candida auris in critically ill patients: Emerging threat in intensive care unit of hospitals

Candida auris has emerged as the multi-drug resistant non-albican candida species in critically ill patients admitted to intensive care units (ICU) causing bloodstream and other infections. It has often been misidentified as Candida famata, Candida sake, Rhodotorula glutinis, or Saccharomyces cerevisiae and Candida haemulonii by automated identification systems. We, in this study, discuss three patients who acquired Candida auris infection after 15 to 20days of their stay in medical ICU. Medical equipment, use of multiple antibiotics, and poor hand hygiene are the most probable predisposing factors attributing to its colonization at multiple anatomical sites leading to bloodstream infection. Candida auris might substantially contaminate the environment of colonized or infected patients making its eradication difficult. Patient screening for Candida auris, especially during prolonged ICU stays, along with strict infection prevention and control strategies needs to be adopted to break its persistence.

No yield penalty under favorable conditions paving the way for successful adoption of flood tolerant rice

Flooding is one of the major constraints for rice production in rainfed lowlands, especially in years and areas of high rainfall. Incorporating the Sub1 (Submergence1) gene into high yielding popular varieties has proven to be the most feasible approach to sustain rice production in submergence-prone areas. Introgression of this QTL into popular varieties has resulted in considerable improvement in yield after flooding. However, its impact under non-flooded conditions or years have not been thoroughly evaluated which is important for the farmers to accept and adopt any new version of their popular varieties. The present study was carried out to evaluate the effect of Sub1 on grain yield of rice in different genetic backgrounds, under non-submergence conditions, over years and locations. The study was carried out using head to head trials in farmer’s fields, which enable the farmers to more accurately compare the performance of Sub1 varieties with their recurrent parents under own management. The data generated from different head to head trials revealed that the grain yield of Sub1 varieties was either statistically similar or higher than their non-Sub1 counterparts under non-submergence conditions. Thus, Sub1 rice varieties show no instance of yield penalty of the introgressed gene.

Anesthetic challenges of extrinsic trachea-bronchial compression due to posterior mediastinal mass: Our experience with a large esophageal mucocele

Large posterior mediastinal masses may lead threatening complications such as critical tracheobronchial compression. Airway management in these individuals is a challenge and being a lower airway obstruction; rescue strategies are limited. We encountered one such case of a large esophageal mucocele causing extrinsic tracheobronchial compression. We have described the anesthetic management of this case using awake fiber-optic assessment followed by intubation. Close communication with the surgical team, meticulous planning of airway management, and early drainage of the mucocele are the cornerstones of management in such patients.

Rapid detection of ethambutol-resistant Mycobacterium tuberculosis in clinical specimens by real-time polymerase chain reaction hybridisation probe method

Background

Early diagnosis of drug resistance (DR) to ethambutol (EMB) in tuberculosis (TB) remains a challenge. Simple and reliable method (s) are needed for rapid detection of DR Mycobacterium tuberculosis (MTB) in clinical specimens.

Objectives

The aim of this study was to design fluorescence resonance energy transfer hybridisation probe-based real-time polymerase chain reaction (PCR) method for the early detection of EMB-resistant MTB direct from clinical sputa.

Materials and Methods

Primers and probes were designed against 306 codon of embB gene which is commonly associated with EMB resistance. A comparative study was done between Lowenstein-Jenson (L-J) proportion and hybridisation probe-based real-time PCR method for susceptibility testing. DNA sequencing was used in nine representative isolates to validate the efficiency of real-time PCR method to detect emb306 mutation of MTB.

Results

A total of 52 clinical sputum samples and corresponding culture isolates (from category II pulmonary TB cases) were included in this study. Out of 52 MTB isolates, 32 and 20 were resistant and susceptible to EMB, respectively, as determined by L-J proportion method. Real-time PCR showed 95% specificity, 75% sensitivity and 82.69% accuracy when compared with L-J proportion method. A 100% of concordance was observed by validating the real-time PCR results with DNA sequencing.

Conclusions

Our real-time PCR hybridisation probe method promises for rapid detection of EMB-resistant MTB directly from clinical specimens. However, future studies and modifications of method by incorporating other potential loci along with targeted mutation (emb306) are still required to increase the sensitivity of method.

Ambient black carbon particulate matter in the coal region of Dhanbad, India

Light-absorbing, atmospheric particles have gained greater attention in recent years because of their direct and indirect impacts on regional and global climate. Atmospheric black carbon (BC) aerosol is a leading climate warming agent, yet uncertainties in the global direct aerosol radiative forcing remain large. Based on a year of aerosol absorption measurements at seven wavelengths, BC concentrations were investigated in Dhanbad, the coal capital of India. Coal is routinely burned for cooking and residential heat as well as in small industries. The mean daily concentrations of ultraviolet-absorbing black carbon measured at 370nm (UVBC) and black carbon measured at 880nm (BC) were 9.8±5.7 and 6.5±3.8μgm^-3, respectively. The difference between UVBC and BC, Delta-C, is an indicator of biomass or residential coal burning and averaged 3.29±4.61μgm^-3. An alternative approach uses the Ǻngstrom Exponent (AE) to estimate the biomass/coal and traffic BC concentrations. Biomass/coal burning contributed ~87% and high temperature, fossil-fuel combustion contributed ~13% to the annual average BC concentration. The post-monsoon seasonal mean UVBC values were 10.9μgm^-3 and BC of 7.2μgm^-3. Potential source contribution function analysis showed that in the post-monsoon season, air masses came from the central and northwestern Indo-Gangetic Plains where there is extensive agricultural burning. The mean winter UVBC and BC concentrations were 15.0 and 10.1μgm^-3, respectively. These higher values were largely produced by local sources under poor dispersion conditions. The direct radiative forcing (DRF) due to UVBC and BC at the surface (SUR) and the top of the atmosphere (TOA) were calculated. The mean atmospheric heating rates due to UVBC and BC were estimated to be 1.40°Kday^-1 and 1.18°Kday^-1, respectively. This high heating rate may affect the monsoon circulation in this region.

Self-Perception of Halitosis among Undergraduate Students of Kathmandu University School of Medical Sciences - A Questionnaire Based Study

Background Halitosis is a frequently reported oral health problem worldwide with a prevalence rate of 10-30% in the general population. It is defined as the disagreeable or foul smelling breath originating consistently from a person's oral cavity. It not only effects the normal daily life activities of the patient but also bring humiliation, reduced self- esteem, ultimately resulting into decreased quality of life. Objective To determine the self-perception of halitosis among undergraduate students of different medical branches of Kathmandu University School of Medical Sciences (KUSMS); Kavre, Nepal. Method A descriptive cross-sectional epidemiological survey was conducted among undergraduate students of Physiotherapy, B.Sc Nursing, Bachelor of Nursing Sciences (BNS), MBBS and BDS program of Kathmandu University School of Medical Sciences, Dhulikhel. A self-administered questionnaire was developed and were distributed among 500 undergraduate students. Result Out of total 500 distributed questionnaires, 406 were completely filled and returned giving an overall response of 81.2%, in which 70 (89.7%) male and 280 (85.4%) female students from different medical branches were aware of the term halitosis. Among them 29 (7.14%) of students think that they suffer from halitosis. Similarly 178 (43.84%) students had severe impact of halitosis on their social life while 153 (37.68%) and 62 (15.27%) students had moderate and mild impact respectively. Conclusion Due to the multifactorial complexity of halitosis, further longitudinal studies including objective assessment of malodor are required to determine its prevalence and to further investigate the association of this problem with other etiological factors in the context of Nepal. Also, curriculum of different fields should be modified to include this simple but very necessary topic.

Identification of mega-environments and rice genotypes for general and specific adaptation to saline and alkaline stresses in India

In the present study, a total of 53 promising salt-tolerant genotypes were tested across 18 salt-affected diverse locations for three years. An attempt was made to identify ideal test locations and mega-environments using GGE biplot analysis. The CSSRI sodic environment was the most discriminating location in individual years as well as over the years and could be used to screen out unstable and salt-sensitive genotypes. Genotypes CSR36, CSR-2K-219, and CSR-2K-262 were found ideal across years. Overall, Genotypes CSR-2K-219, CSR-2K-262, and CSR-2K-242 were found superior and stable among all genotypes with higher mean yields. Different sets of genotypes emerged as winners in saline soils but not in sodic soils; however, Genotype CSR-2K-262 was the only genotype that was best under both saline and alkaline environments over the years. The lack of repeatable associations among locations and repeatable mega-environment groupings indicated the complexity of soil salinity. Hence, a multi-location and multi-year evaluation is indispensable for evaluating the test sites as well as identifying genotypes with consistently specific and wider adaptation to particular agro-climatic zones. The genotypes identified in the present study could be used for commercial cultivation across edaphically challenged areas for sustainable production.

CR-39 track detector for multi-MeV ion spectroscopy

We present the characteristics of track formation on the front and rear surfaces of CR-39 produced by laser-driven protons and carbon ions. A methodological approach, based on bulk etch length, is proposed to uniquely characterize the particle tracks in CR-39, enabling comparative description of the track characteristics in different experiments. The response of CR-39 to ions is studied based on the energy dependent growth rate of the track diameter to understand the intrinsic particle stopping process within the material. A large non-uniformity in the track diameter is observed for CR-39 with thickness matching with the stopping range of particles. Simulation and experimental results show the imprint of longitudinal range straggling for energetic protons. Moreover, by exploiting the energy dependence of the track diameter, the energy resolution (δE/E) of CR-39 for few MeV protons and Carbon ion is found to be about 3%.

Gold nanotriangles: scale up and X-ray radiosensitization effects in mice

In the past decade, there has been considerable interest in radiosensitization using gold nanoparticles that accumulate specifically in cancerous tissue while sparing normal tissues. Despite this interest, it remains unclear which nanoparticle morphologies, cellular uptake, or cytoplasmic distribution elicit optimal radiosensitization. We introduce gold nanotriangles (AuNTs) as a possible X-ray radiotherapy sensitizer. In this study, we first explored a large-scale synthetic method for the production of high quality monodisperse AuNTs. Second, we conducted in vitro and in vivo experiments to evaluate the effect of PEGylated AuNTs (pAuNTs) on cellular uptake, cytotoxicity, bio-distribution, and radiosensitization on radiation-resistant human Glioblastoma Multiforme (GBM) cells. Our results suggest that the new scale up synthesis methodology consistently produced high quality AuNTs and pAuNTs which had nonspecific cellular uptake without any obvious cytotoxicity and exhibited excellent radiosensitization.

Molecular dynamics and pharmacophore modelling studies of different subtype (ALK and EGFR (T790M)) inhibitors in NSCLC

Extensively validated 3D pharmacophore models for ALK (anaplastic lymphoma kinase) and EGFR (T790M) (epithelial growth factor receptor with acquired secondary mutation) were developed. The pharmacophore model for ALK (r² = 0.96, q² = 0.692) suggested that two hydrogen bond acceptors and three hydrophobic groups arranged in 3-D space are essential for the binding affinity of ALK inhibitors. Similarly, the pharmacophore model for EGFR (T790M) (r² = 0.92, q² = 0.72) suggested that the presence of a hydrogen bond acceptor, two hydrogen bond donors and a hydrophobic group plays vital role in binding of an inhibitor of EGFR (T790M). These pharmacophore models allowed searches for novel ALK and EGFR (T790M) dual inhibitors from multiconformer 3D databases (Asinex, Chembridge and Maybridge). Finally, the eight best hits were selected for molecular dynamics simulation, to study the stability of their complexes with both proteins and final binding orientations of these molecules. After molecular dynamics simulations, one hit has been predicted to possess good binding affinity for both ALK and EGFR (T790M), which can be further investigated for its experimental in-vitro/in-vivo activities.

Determination of Sex from the Foramen Magnum using 3DCT: A Nepalese Study

Background Identification is of utmost importance in any medicolegal investigation with sex determination being one of the principle indicators of identity. Sexing of bones becomes easy when the skeletal remains are complete. However, the problem arises when the bones are fragmented. Many researchers have undertaken several studies in different populations to determine the sex with reasonable accuracy using numerous measurements of the skull including those of the foramen magnum. Objective The present study was aimed to find the sexual dimorphism of the foramen magnum in the Nepalese population by analyzing the antero-posterior length, transverse diameter and area of the foramen magnum. Method The antero-posterior length and transverse diameter of the foramen magnum were measured using three-dimensional computed tomography (3DCT) images of the head in a cohort of 100 Nepalese subjects. Radinsky's and Teixeria's formulae were used to calculate the area of the foramen magnum. Discriminate function analysis was used to analyze sex differences. Result Mean values of antero-posterior length and transverse diameter of the foramen magnum in males were higher than in females. The mean of the area calculated using Radinsky's formula was smaller than that calculated by Teixeira's formula and the areas calculated were higher in males. The measurements of the foramen magnum and the areas calculated showed significant difference (p<0.001) between males and females. Discriminate function analysis for the measurements of the foramen magnum and the areas calculated showed high predictability for both the sexes. Discriminate function analysis showed a maximum predictability of 75%. Conclusion Considering the percent of predictability of sex from the various variables related to the foramen magnum in the Nepalese population, it can be concluded that its restricted applicability in forensic investigations should be constrained to cases of fragmentary skull bases.