Showing papers by "International Centre for Diarrhoeal Disease Research, Bangladesh published in 2022"

An Efficient Analytical Approach for the Periodicity of Nano/Microelectromechanical Systems’ Oscillators

Abstract: Periodic behavior analysis of nano/microelectromechanical systems (N/MEMS) is an essential field owing to their many promising applications in microinstruments. The interesting and unique properties of these systems, particularly, small size, batch fabrication, low power consumption, and high reliability, have fascinated researchers and industries to implement these structures for the production of different microdevices. The dynamic oscillatory behavior of N/MEMS is very intricate due to the various types of nonlinearities present in these structures. The foremost objective of this study is to explore the periodicity of oscillatory problems from N/MEMS. The variational iteration method (VIM), which has been considered as an effective approach for nonlinear oscillators, is coupled with the Laplace transform to obtain the approximate analytic solution of these nonlinear vibratory systems with fewer computations. This coupling of VIM and Laplace transform not only helps in the identification of the Lagrange multiplier without getting into the details of the cryptic theory of variations, but also finds the frequency-amplitude relationship and the analytic approximate solution of N/MEMS. A generalized vibratory equation for N/MEMS is followed by three examples as special cases of this generalized equation are given to elucidate the effectivity of the coupling. The solution obtained from the Laplace-based VIM not only exhibits good agreement with observations numerically but also higher accuracy yields when compared to other established techniques in the open literature.

Characteristics and birth outcomes of pregnant adolescents compared to older women: An analysis of individual level data from 140,000 mothers from 20 RCTs

Abstract: Adolescence is a critical period of maturation when nutrient needs are high, especially among adolescents entering pregnancy. Using individual-level data from 140,000 participants, we examined socioeconomic, nutrition, and pregnancy and birth outcomes for adolescent mothers (10-19 years) compared to older mothers in low and middle-income countries.This study was conducted between March 16, 2018 and May 25, 2021. Data were obtained from 20 randomised controlled trials of micronutrient supplementation in pregnancy. Stratified analyses were conducted by age (10-14 years, 15-17 years, 18-19 years, 20-29 years, 30-39 years, 40+ years) and geographical region (Africa, Asia). Crude and confounder-adjusted means, prevalence and relative risks of pregnancy, nutrition and birth outcomes were estimated using multivariable linear and log-binomial regression models with 95% confidence intervals.Adolescent mothers comprised 31.6% of our data. Preterm birth, small-for-gestational age (SGA), low birthweight (LBW) and newborn mortality followed a U-shaped trend in which prevalence was highest among the youngest mothers (10-14 years) and then reduced gradually, but increased again for older mothers (40+ years). When compared to mothers aged 20-29 years, there was a 23% increased risk of preterm birth, a 60% increased risk of perinatal mortality, a 63% increased risk of neonatal mortality, a 28% increased risk of LBW, and a 22% increased risk of SGA among mothers 10-14 years. Mothers 40+ years experienced a 22% increased risk of preterm birth and a 103% increased risk of stillbirth when compared to the 20-29 year group.The youngest and oldest mothers suffer most from adverse pregnancy and birth outcomes. Policy and programming agendas should consider both biological and socioeconomic/environmental factors when targeting these populations.Bill and Melinda Gates Foundation (Grant No: OP1137750).

Incidence of Asymptomatic Shigella Infection and Association with the Composite Index of Anthropometric Failure among Children Aged 1–24 Months in Low-Resource Settings

Abstract: Asymptomatic or subclinical infection by diarrheal enteropathogens during childhood has been linked to poor health and nutritional outcomes. In this study, we aimed to assess the impact of asymptomatic Shigella infection on different forms of childhood malnutrition including the composite index of anthropometric failure (CIAF). We used data from 1715 children enrolled in the multi-country birth cohort study, MAL-ED, from November 2009 to February 2012. Monthly non-diarrheal stools were collected and assessed using TaqMan Array Cards (TAC). Poisson regression was used to calculate incidence rates of asymptomatic Shigella infection. Generalized estimating equations (GEE) were used to assess the association between asymptomatic Shigella infection and nutritional indicators after adjusting for relevant covariates. Incidence rates per 100 child-months were higher in Tanzania, Bangladesh and Peru. Overall, after adjusting for relevant covariates, asymptomatic Shigella infection was significantly associated with stunting (aOR 1.60; 95% CI: 1.50, 1.70), wasting (aOR 1.26; 95% CI: 1.09, 1.46), underweight (aOR 1.45; 95% CI: 1.35, 1.56), and CIAF (aOR 1.55; 95% CI: 1.46, 1.65) in all the study sites except for Brazil. The high incidence rates of asymptomatic Shigella infection underscore the immediate need for Shigella vaccines to avert the long-term sequelae involving childhood growth.

Post-quantum Signature Scheme to Secure Medical Data

Abstract: Quantum computers are considered to have the ability to change the landscape of data security in near future. In recent years, progress on this matter showed us that quantum computers can solve certain computational problems significantly faster than classical computers. Some firms or organizations claim to have constructed the world’s most powerful quantum computer, which is far more powerful than today’s classical computers. So, the concerning fact is that, the most secure ledger, blockchain now is facing critical issues of privacy and security. Cryptographic hash is one of the strongest tools in the cryptographic arena that is used in blockchain applications for confidentiality. However, cryptographic hash is certainly breakable under quantum computing because of Grover’s and Shor’s algorithm. To make a secure blockchain for sensitive medical data, we have to move into post-quantum blockchain. Under these circumstances, the proposed signature scheme is based on the combination of two SHA-3 finalists (Keccak-512 and Skein-512) and Merkle tree which will be suitable for blockchain technology. By exploiting the structure and properties of sponge function, Skein-512, and Merkle tree, the proposed scheme can achieve a certain benchmark of security and flexibility. Moreover, the proposed signature scheme can easily adopt the existing blockchain applications under the cloud environment.

Visual Impairment and Risk of Self-Reported Road Traffic Crashes Among Bus Drivers in Bangladesh

Abstract: This study assesses the prevalence and the causes of visual impairment among bus drivers undergoing screening in Bangladesh and associations with self-reported crashes.Eye health screenings including refraction and questionnaires were conducted at 10 bus terminals in 7 districts of Bangladesh from June through August 2019. Presenting near and distance visual impairment and self-reported road traffic crashes were recorded.Among 700 participants, nearly 1 in 5 (n = 126, 18.0%) had presented visual acuity (VA) in the better-seeing eye ≤6/9, not meeting the vision standard of Bangladesh for bus drivers. A majority of drivers (n = 492, 70.3%) had near or distance refractive error, and most who failed to reach the driving standard (88.1%, n = 111) could be improved with readily available treatment, either glasses or cataract surgery. A history of 1 or more road traffic crashes while driving a bus or minibus was reported by 62 (8.97%) participants. In multivariable models, factors significantly associated with near or distance visual impairment included older age [odds ratio (OR) per year 1.15, 95% confidence interval (CI): 1.12-1.18, P < 0.0001] and having no driver's license (OR 1.80, 95% CI: 1.04-3.13, P = 0.037). Self-reported history of a motor vehicle crash was associated with near or distance visual impairment (OR 2.45, 95% CI: 1.09-5.49, P = 0.030), even when adjusting for other factors such as age and weekly miles are driven.Ensuring that bus drivers are screened to meet the required visual standards for driving while referring those who do not for treatment, can contribute to safer roads in this high-risk setting.

Dynamics of epibenthic copepods in relation to environmental factors and phytoplankton abundance in tropical river, estuarine and coastal environments

Abstract: Changes in epibenthic copepod populations markedly affect the population of benthic dwelling animals in rivers, estuaries and marine ecosystems. Unfortunately, studies focusing the environmental influence on the structure of epibenthic copepods are lacking. This study addresses the deficit of information focusing the environmental factors that affect the structure of epibenthic copepods in various lotic environments. The copepods community and environmental variables in water 0.3 m above the bottom of four areas (from 10 km upstream of the Kuantan River mouth to 5 km offshore) were studied monthly over one-year. The study area is characterised by a hot equatorial climate with the monsoon (more-rainy summer, October–March) and the non-monsoon (less-rainy summer, April–September). Totally forty-three species of copepods on thirteen groups were recorded, with harpacticoid copepod groups being dominant in all sampling zones except the upstream zone, where freshwater copepods were dominant and harpacticoid copepods were absent. The total abundance of copepods was greater at the coast and estuary than at the river. Phytoplankton density, salinity, total suspended solids (TSS) and dissolved oxygen (DO) significantly influenced the abundance of epibenthic copepod groups, but their influence on copepods was zone-specific. At the coastal and the estuarine zones, harpacticoid copepod groups were positively influenced by the abundance of phytoplankton, whereas the other copepod groups were negatively influenced by the TSS. The influence of TSS on cyclopoid and calanoid copepods was dependent on the density of phytoplankton with a higher density reducing the impact of TSS. At the downstream, harpacticoid copepod groups were positively influenced by the abundance of phytoplankton, DO and salinity while the other copepod groups were positively influenced by DO and salinity and negatively influenced by TSS. At the upstream, freshwater copepod groups were positively influenced by the DO concentration and negatively influenced by the salinity while, other copepod groups were positively influenced by both DO and salinity. Other environmental variables had a weak and insignificant influence on the densities of observed copepod groups. Both monsoon and non-monsoon seasons equally influenced the observed copepod groups. The observed results need to be regularly monitored to changing tropical environments for better elucidating the ecology of various groups of epibenthic copepods associated with the climate change and various anthropogenic activities.

Health problems among Forcibly Displaced Myanmar Nationals (FDMNs) admitted to the Medicine ward of Cox's Bazar Medical College Hospital

Abstract: : Forcibly displaced Myanmar nationals (FDMNs) or Rohingya refugees are one of the vulnerable groups suffering from different kinds of health problems but have been less reported yet. Therefore, the study was designed to delineate the health problems among FDMNs admitted to Cox's Bazar Medical College Hospital. : This hospital-based cross-sectional study was conducted at the Medicine ward, Cox's Bazar Medical College Hospital, for a six-month period following approval. Rohingya refugees who were admitted during the study period were approached for inclusion. Informed written consent was ensured prior to participation. A structured questionnaire was used during data collection. Collected information was recorded in case record form. A total of 290 subjects were interviewed. Analysis was performed using the statistical package for social science (SPSS) version 20. : The mean age of the participants was 48.76±18.67 years (range: 16-91), with a clear male predominance (60.7%). Family size ranged 6-8. All of the participants reported at least one of the illnesses. Of all, 29.66% patients had disease of the respiratory system, and 26.9% had disease of the gastrointestinal and hepatobiliary system. Accidental injury or injury due to electrocution or thin falls or snake bites was present in 10.4% of the cases. Among the single most common diseases, COPD (20%) was the most frequently observed, and the rest of them were chronic liver disease (13.1%), pulmonary TB (5.5%), ischemic stroke (5.5%), CAP (4.1%), acute coronary syndrome (3.4%), thalassaemia (3.4%) and hepatocellular carcinoma (3.4%). Among the top 6 diagnosed diseases, PTB was more common in elderly individuals (p=0.29). The disease pattern was similar across the sexes among the refugees except community acquisition pneumonia (CAP), which was commonly observed among males (p=.004). Considering different age groups, genitourinary problems were more common in males aged >60 years, and rheumatology and musculoskeletal problems were equally affected in females aged between 40-60 years. : COPD, CLD and CAP were the most prevalent diseases in FDMN patients who attended the medicine ward of Cox's Bazar Medical College Hospital. Further exploration is warranted before any policy making and comprehensive plan.

Online Detection and Estimation of Parameter Jumps.

Abstract: In many dynamic systems, the parameters are subject to jumps at unknown points in time. The jumps may be the result of some change in the operating system, or plant failure. In this work a method has been developed for fast detection of these jumps and estimation of the post-jump values. The proposed method is called the Combined Filter Algorithm. It is based on the conventional Kalman filter. Single-sample hypothesis test is used to determine the presence or absence of jumps. Small jumps, missed by the hypothesis test, are traced by a Random Walk Model Kalman filter. This is made possible by the introduction of a new kind of decision rule, called the Combined Decision Rule. The properties of this filter under correct and incorrect decisions are studied, and mathematical proofs are presented. The intended main application of the algorithm is the detection of power system faults and estimation of steady-state voltages and currents. The proposed algorithm is tested for ARMA models and discrete state models. The algorithm is also tested on a continuous-time system, where a jump occurs in one parameter. The algorithm is applied to detect and estimate the resulting changes produced in an equivalent ARMA model. Simulation results are presented.

Environmental enteric dysfunction and small intestinal histomorphology of stunted children in Bangladesh

Abstract: Abstract There is lack of information on the histological characteristics of the intestinal mucosa in Bangladeshi children, which is considered to be the traditional gold standard for diagnosis of environmental enteric dysfunction (EED). The purpose of the study was to evaluate the intestinal histological characteristics of stunted children aged between 12-18 months with possible EED. 110 children with chronic malnutrition (52 stunted with length-for-age Z score, LAZ<-2 and 58 at risk of stunting with LAZ <-1 to -2) from the Bangladesh Environmental Enteric Dysfunction (BEED) study protocol who underwent upper gastrointestinal (GI) endoscopy were selected for this study. To explore the association of EED with childhood stunting, upper GI endoscopy was done and the biopsy specimens were studied for histopathology. Villous height and crypt depth were measured and the presence and intensity of inflammatory infiltrates in the lamina propria was investigated. Bivariate analysis was performed to examine the relationship between stunting and histologic morphology. More than 90% children irrespective of nutritional status were diagnosed to have chronic non-specific duodenitis on histopathology. Half of the children from both groups had villous atrophy as well as crypt hyperplasia and lymphocytic infiltration was present in more than 90% children, irrespective of groups. However, no statistically significant difference was observed when compared between the groups. The prevalence of chronic non-specific duodenitis in Bangladeshi children, irrespective of nutritional status, was high. A significant number of these children had abnormal findings in intestinal histomorphology. Author Summary EED or environmental enteropathy, results in poor gut health and suboptimal child growth, and is considered to play a major role on childhood stunting in the tropics. Growth faltering due to decreased nutrient absorption as a result of alteration of small intestinal histological structure manifested as blunting or atrophy of intestinal villi, hyperplasia or elongation of crypts and infiltration of inflammatory cells in the lamina propria, has been demonstrated as the basic characteristics of EED. The traditional gold standard for the diagnosis of EED is intestinal biopsy and assessment of the histomorphological alterations. There is lack of information on the histological characteristics of the intestinal mucosa in Bangladeshi children. The purpose of the study was to evaluate the intestinal histological characteristics of stunted children aged between 12-18 months with possible EED. 110 children with chronic malnutrition who underwent upper gastrointestinal (GI) endoscopy were selected for this study and the biopsy specimens were studied for histopathology. Villous height and crypt depth were measured and the presence and intensity of inflammatory infiltrates in the lamina propria was investigated. More than 90% children irrespective of nutritional status were diagnosed to have chronic non-specific duodenitis. Half of the children from both groups had villous atrophy as well as crypt hyperplasia and lymphocytic infiltration was present in more than 90% children, irrespective of groups. However, no statistically significant difference was observed when compared between the groups.

Vaccine Approach for Human Monkeypox over the Years and Current Recommendations to Prevent the Outbreak: A Rapid Review

Abstract: World Health Organization declared human monkeypox a global health emergency on 23 July 2022. This indicates that the outbreak poses a serious risk to global health and requires a united worldwide response to stop the virus from spreading and possibly turning into a pandemic. Vaccines can play a vital role in this context, contributing to pre- and post-exposure prophylaxis. Our rapid review aimed to go through the background of the vaccine approach for human monkeypox over the years and to find out what current guidelines are highlighting relating to it. 22 relevant published articles from MEDLINE bibliographic database and 8 vaccine recommendations from manual searching have been deliberated here. The significant synopsis of this review is that the smallpox vaccine is the only immunization option for monkeypox so far, and it is up to 85% effective to prevent the infection. Third-generation smallpox vaccines are advised over first and second generations due to their minimal side effects. Healthcare providers and lab professionals at risk are on the priority list to get vaccinated, as well as pregnant women or lactating mothers, immunocompromised or chronically ill patients, can get vaccinated if they are surely exposed to the monkeypox infection. Lastly, JYNNEOS/ IMVAMUNE is the current most preferable smallpox vaccine that is highly advised for the latest outbreak of human monkeypox but more clinical trials on humans should be conducted to evaluate its safety, efficacy, and adverse events.

Understanding and Predicting Characteristics of Test Collections in Information Retrieval

Abstract: Research community evaluations in information retrieval, such as NIST’s Text REtrieval Conference (TREC), build reusable test collections by pooling document rankings submitted by many teams. Naturally, the quality of the resulting test collection thus greatly depends on the number of participating teams and the quality of their submitted runs. In this work, we investigate: i) how the number of participants, coupled with other factors, affects the quality of a test collection; and ii) whether the quality of a test collection can be inferred prior to collecting relevance judgments from human assessors. Experiments conducted on six TREC collections illustrate how the number of teams interacts with various other factors to influence the resulting quality of test collections. We also show that the reusability of a test collection can be predicted with high accuracy when the same document collection is used for successive years in an evaluation campaign, as is common in TREC.

High diversity and transmission dynamics of HIV-1 non-C subtypes in Bangladesh

Abstract: BACKGROUND. Genetic diversity and molecular epidemiology of HIV are directly relevant to HIV transmission. We report here the genetic diversity and transmission dynamics of non-C subtypes of HIV-1 strains detected in Bangladeshi key populations. RESULTS. Sequence analysis of _gag_ gene revealed four subtypes A1, B, D, G and nine CRFs (01_AE, 02_AG, 09_cpx, 10_CD, 15_AE/B, 13_cpx, 14_BG, 22_01_A1 and 25_AGU). Most of these non-C strains were detected in returnee migrant workers from different parts of the world. Phylogenetic analysis showed that the Bangladeshi HIV-1 strains detected in migrant workers and their wives and local sex workers shared common ancestries. CONCLUSIONS. Identification of the multiple subtypes indicates high diversity of non-C HIV-1 variants circulating in Bangladesh which might have been imported by migrant workers from multiple geographical areas.

Computing Fault-Tolerant Metric Dimension of Connected Graphs

Abstract: For a connected graph, the concept of metric dimension contributes an important role in computer networking and in the formation of chemical structures. Among the various types of the metric dimensions, the fault-tolerant metric dimension has attained much more attention by the researchers in the last decade. In this study, the mixed fault-tolerant dimension of rooted product of a graph with path graph with reference to a pendant vertex of path graph is determined. In general, the necessary and sufficient conditions for graphs of order at least 3 having mixed fault-tolerant generators are established. Moreover, the mixed fault-tolerant metric generator is determined for graphs having shortest cycle length at least 4.