Identification of amelogenin gene on burnt teeth samples through nested polymerase chain reaction amplification for sex identification

Sex determination is one of the basic components in victim identification. This study aims to ascertain the sex of an individual from burnt teeth samples exposed at different temperature and time through nested polymerase chain reaction (PCR) on the amelogenin (AMEL) sex marker, to calculate the specificity and sensitivity, and to compare with previous relevant studies. A total of 17 teeth samples was subjected to burning at different temperatures ranging from 100°C to 500°C, at 2 to 10 minutes. The whole tooth was used for deoxyribonucleic acid (DNA) extraction by phenol-chloroform method. All samples were quantified for DNA concentration and then analyzed with nested PCR using two pairs of AMEL primer and results of sex typing were recorded. Out of 17 samples, genomic DNA extracted from 6 samples have concentrations ranging from 27.3 – 130.6 ng/μL. Nested PCR could amplify 16 samples for AMEL gene. Sex typing using AMEL gene showed 76.47% accuracy. Sensitivity of AMEL primer was increased from 6.67% to 63.64% using nested PCR technique; specificity of both external and internal primer was reported at 100%. Nested PCR of AMEL gene proved to be a suitable method for unequivocal determination of sex from degraded DNA samples

Convergence Study for Rock Unconfined Compression Test Using Discrete Element Method

Mesh convergence is a vital issue that needs to be addressed in a numerical model. This study investigated the effects of mesh element number on the Discrete Element Method (DEM) to granite rock response under compression loading. This study used the 3D finite-element code LS-DYNA to model the Unconfined Compression Test (UCT) numerical simulation. Models with five different mesh types were conducted for convergence mesh, namely normal mesh, fine mesh, super fine mesh, coarse mesh, and super coarse mesh. The mesh convergence of rock media has been conducted using DEM and steel plates simulated using the Finite Element Method (FEM). The DEM-FEM numerical analysis is compared with the results obtained from the experimental test. The best mesh was obtained as the simulation could reproduce the stress-strain curve trends, the failure behaviour and compression strength observed in the experimental test. The normal mesh was selected as the best mesh type in this study based on the comparisons that have been made. This study shows that the DEM-FEM numerical simulation can represent granite rock and can be used for further study based on mesh convergence

Impact of Vibration on Double-Porosity Unsaturated Laterite Soil with Different Water Contents

Engineering practices, natural and man-made vibrations phenomena such as blasting, construction machinery and operations, and vehicle traffic vibrations can cause stresses to soils. In addition, changes in moisture content may affect the speed of liquid penetrating the soils. Therefore, the impacts due to vibrations and changes in moisture contents need to be addressed to ensure geo-environment sustainability. This can be achieved by conducting laboratory experiments to determine the behaviour of deformable double-porosity soil samples with different water contents subjected to non-repeated vibrations. In this study, aggregated laterite soil samples were prepared with 30% and 34% moisture contents. Each aggregated soil was poured into an acrylic column then the soil was compressed to a pre-determined height of 10 cm. Testing was performed on each soil column using a vibrating table where accelerometers were installed to measure high-frequency acceleration time histories on the surfaces of the vibrating table and laterite soil. The tests were conducted by increasing the amplitude of displacement and the acceleration time histories were collected to record maximum amplitudes. The results showed that the soil surface acceleration in non-repeated vibration was increased with increasing moisture contents. It was also discovered that the speed of liquid penetration was influenced by vibration due to rearrangement of soil particles and changes in soil structure and porosity characteristics

Impact of Vibration on Double-Porosity Unsaturated Laterite Soil with Different Water Contents

Engineering practices, natural and man-made vibrations phenomena such as blasting, construction machinery and operations, and vehicle traffic vibrations can cause stresses to soils. In addition, changes in moisture content may affect the speed of liquid penetrating the soils. Therefore, the impacts due to vibrations and changes in moisture contents need to be addressed to ensure geo-environment sustainability. This can be achieved by conducting laboratory experiments to determine the behaviour of deformable double-porosity soil samples with different water contents subjected to non-repeated vibrations. In this study, aggregated laterite soil samples were prepared with 30% and 34% moisture contents. Each aggregated soil was poured into an acrylic column then the soil was compressed to a pre-determined height of 10 cm. Testing was performed on each soil column using a vibrating table where accelerometers were installed to measure high-frequency acceleration time histories on the surfaces of the vibrating table and laterite soil. The tests were conducted by increasing the amplitude of displacement and the acceleration time histories were collected to record maximum amplitudes. The results showed that the soil surface acceleration in non-repeated vibration was increased with increasing moisture contents. It was also discovered that the speed of liquid penetration was influenced by vibration due to rearrangement of soil particles and changes in soil structure and porosity characteristics

Use of digital image technique to study leachate penetration in biocemented residual soil

Recently, biocementation has become a trend of soil improvement. Nevertheless, few studies were conducted in its application to improve engineering properties of fine-grained soil. In this study, digital image technique (DIT) was employed to determine the effect of biocementation via enzymatic induced calcium carbonate precipitation (EICP) technique on the leachate penetration pattern and medium-term hydraulic conductivity of the compacted residual soil made from fine-grained soil. The findings have shown that the of leachate penetration pattern and hydraulic conductivities of the EICP treated soils were considerably affected by the formation of biocementation or CaCO3precipitation. It was found that the rate of leachate penetration was faster within the first 14 days of the test. It was also determined that at the end of 28 days, the amount of leachate penetrated the untreated soil, 0.50 M, and 1.0 M EICP treated soils were 14.16 mm, 10.08 mm, and 6.03 mm, respectively. The results have shown that EICP treatment resulted in the reduction of hydraulic conductivity by 28. 28.83% and 41.33% in 0.50 M and 1.00 M treated soils, respectively

Polysubstance use among adolescents in Malaysia: Findings from the National Health and Morbidity Survey 2017.

BackgroundPolysubstance use is defined as the use of more than one non-prescribed licit or illicit substance either concurrently or simultaneously. This study aimed to determine the prevalence of single substance users and polysubstance users and 'their associated factors among adolescents in Malaysia.MethodsThis study was a secondary data analysis from the National Health and Morbidity Survey (NHMS) 2017, a cross-sectional survey conducted among Malaysian school-going adolescents aged 13 to 17. The NHMS utilised a two-stage stratified cluster sampling. Multivariate Multinomial Logistic Regression analysis was applied.ResultsThe overall prevalence of single substance use and polysubstance use among adolescents were 17.2% and 5.1% respectively. The multinomial model showed a higher likelihood of being single or polysubstance user among male (single user OR = 3.0, poly user OR = 4.6), others Bumiputeras vs Malay (single user OR = 1.7, poly user OR = 5.3), those who live with a single parent (single user OR = 1.2, poly user OR = 1.4), involved in truancy (single user OR = 1.7, poly user OR = 3.6) and being bullied (single user OR = 1.3, poly user OR = 3.4), those who had lack of peer support (single user OR = 1.3, poly user OR = 1.4), poor parental bonding (single user OR = 1.4, poly user OR = 1.8), depression (single user OR = 1.4, poly user OR = 3.2) and those who had no close friend (single user OR = 1.3, poly user OR = 2.7).ConclusionOur study highlighted multiple significant associated factors of single and polysubstance use among adolescents in Malaysia. This result can assist in the development of specific intervention and prevention programs targeting high-risk groups

Characteristics and outcomes of an international cohort of 600 000 hospitalized patients with COVID-19

Background: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world's largest international, standardized data sets concerning hospitalized patients. Methods: The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results: Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60 years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions: Age was the strongest determinant of risk of death, with a ∼30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death. The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death

ISARIC-COVID-19 dataset: A Prospective, Standardized, Global Dataset of Patients Hospitalized with COVID-19

The International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) COVID-19 dataset is one of the largest international databases of prospectively collected clinical data on people hospitalized with COVID-19. This dataset was compiled during the COVID-19 pandemic by a network of hospitals that collect data using the ISARIC-World Health Organization Clinical Characterization Protocol and data tools. The database includes data from more than 705,000 patients, collected in more than 60 countries and 1,500 centres worldwide. Patient data are available from acute hospital admissions with COVID-19 and outpatient follow-ups. The data include signs and symptoms, pre-existing comorbidities, vital signs, chronic and acute treatments, complications, dates of hospitalization and discharge, mortality, viral strains, vaccination status, and other data. Here, we present the dataset characteristics, explain its architecture and how to gain access, and provide tools to facilitate its use

The value of open-source clinical science in pandemic response: lessons from ISARIC

International audienc