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Optimal selection of mother wavelet for accurate infant cry classification

Saraswathy J, Hariharan M, Nadarajaw T, Khairunizam W, Yaacob S

Australas Phys Eng Sci Med, 2014 Jun;37(2):439-56.
PMID: 24691930 DOI: 10.1007/s13246-014-0264-y

Wavelet theory is emerging as one of the prevalent tool in signal and image processing applications. However, the most suitable mother wavelet for these applications is still a relative question mark amongst researchers. Selection of best mother wavelet through parameterization leads to better findings for the analysis in comparison to random selection. The objective of this article is to compare the performance of the existing members of mother wavelets and to select the most suitable mother wavelet for accurate infant cry classification. Optimal wavelet is found using three different criteria namely the degree of similarity of mother wavelets, regularity of mother wavelets and accuracy of correct recognition during classification processes. Recorded normal and pathological infant cry signals are decomposed into five levels using wavelet packet transform. Energy and entropy features are extracted at different sub bands of cry signals and their effectiveness are tested with four supervised neural network architectures. Findings of this study expound that, the Finite impulse response based approximation of Meyer is the best wavelet candidate for accurate infant cry classification analysis.
Improved binary dragonfly optimization algorithm and wavelet packet based non-linear features for infant cry classification

Hariharan M, Sindhu R, Vijean V, Yazid H, Nadarajaw T, Yaacob S, et al.

Comput Methods Programs Biomed, 2018 Mar;155:39-51.
PMID: 29512503 DOI: 10.1016/j.cmpb.2017.11.021

BACKGROUND AND OBJECTIVE: Infant cry signal carries several levels of information about the reason for crying (hunger, pain, sleepiness and discomfort) or the pathological status (asphyxia, deaf, jaundice, premature condition and autism, etc.) of an infant and therefore suited for early diagnosis. In this work, combination of wavelet packet based features and Improved Binary Dragonfly Optimization based feature selection method was proposed to classify the different types of infant cry signals.
METHODS: Cry signals from 2 different databases were utilized. First database contains 507 cry samples of normal (N), 340 cry samples of asphyxia (A), 879 cry samples of deaf (D), 350 cry samples of hungry (H) and 192 cry samples of pain (P). Second database contains 513 cry samples of jaundice (J), 531 samples of premature (Prem) and 45 samples of normal (N). Wavelet packet transform based energy and non-linear entropies (496 features), Linear Predictive Coding (LPC) based cepstral features (56 features), Mel-frequency Cepstral Coefficients (MFCCs) were extracted (16 features). The combined feature set consists of 568 features. To overcome the curse of dimensionality issue, improved binary dragonfly optimization algorithm (IBDFO) was proposed to select the most salient attributes or features. Finally, Extreme Learning Machine (ELM) kernel classifier was used to classify the different types of infant cry signals using all the features and highly informative features as well.
RESULTS: Several experiments of two-class and multi-class classification of cry signals were conducted. In binary or two-class experiments, maximum accuracy of 90.18% for H Vs P, 100% for A Vs N, 100% for D Vs N and 97.61% J Vs Prem was achieved using the features selected (only 204 features out of 568) by IBDFO. For the classification of multiple cry signals (multi-class problem), the selected features could differentiate between three classes (N, A & D) with the accuracy of 100% and seven classes with the accuracy of 97.62%.
CONCLUSION: The experimental results indicated that the proposed combination of feature extraction and selection method offers suitable classification accuracy and may be employed to detect the subtle changes in the cry signals.
Fulltext Bullying and Its Associated Individual, Peer, Family and School Factors: Evidence from Malaysian National Secondary School Students

Sabramani V, Idris IB, Ismail H, Nadarajaw T, Zakaria E, Kamaluddin MR

Int J Environ Res Public Health, 2021 Jul 05;18(13).
PMID: 34281145 DOI: 10.3390/ijerph18137208

Adolescents involved in bullying can be at risk of developing behavioural problems, physical health problems and suicidal ideation. In view of this, a quantitative research design using a cross-sectional study was conducted to determine the prevalence of bullying and associated individual, peer, family and school factors. The study involved 4469 Malaysian public-school students who made up the response rate of 89.4%. The students were selected using a randomized multilevel sampling method. The study found that 79.1% of student respondents were involved in bullying as perpetrators (14.4%), victims (16.3%), or bully-victims (48.4%). In a multivariate analysis, the individual domain showed a significant association between students' bullying involvement and age (OR = 1.38; 95% CI 1.12-1.70), gender (OR = 1.73; 95% CI 1.47-0.91), ethnicity (OR = 0.66; 95% CI 0.47-0.91), duration of time spent on social media during the weekends (OR = 1.43; 95% CI 1.09-1.87) and psychological distress level (OR = 2.55; 95% CI 1.94-3.34). In the peer domain, the significantly associated factors were the number of peers (OR = 0.69; 95% CI 0.56-0.86) and frequency of quarrels or fights with peers (OR = 2.12; 95% CI 1.24-3.26). Among the items in the school domain, the significantly associated factors were students being mischievous in classrooms (OR = 1.52; 95% CI 1.06-2.06), student's affection towards their teachers (OR = 1.53; 95% CI 1.06-2.20), frequency of appraisal from teachers (OR = 1.49; 95% CI 1.16-1.94), frequency of friends being helpful in classrooms (OR = 1.92; 95% CI 1.09-3.38) and frequency of deliberately skipping class (OR = 2.91; 95% CI 2.90-1.72). As a conclusion, the study revealed high levels and widespread bullying involvement among students in Malaysia. As such, timely bullying preventions and interventions are essential, especially in terms of enhancing their mental health capacity, which substantially influences the reduction in the prevalence rates of bullying involvement among students in Malaysia.
Association of common genetic variants with vitamin D status in Malaysian children with epilepsy

Kong AN, Fong CY, Ng CC, Mohamed AR, Khoo TB, Ng RL, et al.

Seizure, 2020 Jul;79:103-111.
PMID: 32464532 DOI: 10.1016/j.seizure.2020.05.009

PURPOSE: Children with epilepsy (CWE) are at risk of vitamin D deficiency. Single nucleotide polymorphisms (SNPs) affecting the vitamin D pathway are potentially important risk factors for serum 25-hydroxyvitamin D [25(OH)D] concentration. The aims of our study were to evaluate the association of vitamin d-related SNPs to serum 25(OH)D concentrations in Malaysian CWE.
METHODS: Cross-sectional study of Malaysian ambulant CWE on antiseizure medication for >1 year. Sixteen SNPs in 8 genes (GC, VDR, CYP2R1, CYP24A1, CYP27B1, CYP27A1, CYP3A4, NADSYN1/DHCR7) were genotyped. Linear and logistic regression models and co-variates adjusted analyses were used. SNPs with significant associations were further analysed in a group of ethnically-matched healthy Malaysian children.
RESULTS: 239 CWE were recruited (52.7% Malay, 24.3% Chinese and 23.0% Indian) with mean serum 25(OH)D of 58.8 nmol/L (SD 25.7). Prevalence of vitamin D deficiency (≤37.5 nmol/L) was 23.0%. Minor allele of GC-rs4588-A was associated with lower serum 25(OH)D in the meta-analysis of both CWE (β -8.11, P = 0.002) and Malaysian healthy children (β -5.08, P < 0.001), while VDR-rs7975232-A was significantly associated with reduced odds of vitamin D deficiency in Malay subgroup of CWE (OR: 0.16; 95% CI: 0.06-0.49; P = 0.001) and this association was not found in the healthy children group.
CONCLUSIONS: Our results suggest that GC-rs4588 is associated with lower serum 25(OH)D concentration in both Malaysian CWE and healthy children, while VDR-rs7975232A is associated with lower risk of vitamin D deficiency in Malaysian CWE of Malay ethnicity. Our findings may assist in the genetic risk stratification of low vitamin D status among CWE.
Fulltext Vitamin D deficiency and its risk factors in Malaysian children with epilepsy

Fong CY, Kong AN, Poh BK, Mohamed AR, Khoo TB, Ng RL, et al.

Epilepsia, 2016 08;57(8):1271-9.
PMID: 27378185 DOI: 10.1111/epi.13443

OBJECTIVE: Long-term use of antiepileptic drugs (AEDs) is a significant risk factor for vitamin D deficiency in children with epilepsy. The aims of our study were to evaluate the prevalence and risk factors for vitamin D deficiency among Malaysian children with epilepsy.
METHODS: Cross-sectional study of ambulant children with epilepsy on long-term AEDs for >1 year seen in three tertiary hospitals in Malaysia from April 2014 to April 2015. Detailed assessment of pubertal status, skin pigmentation, sunshine exposure behavior, physical activity, dietary vitamin D and calcium intake, anthropometric measurements and bone health blood tests (vitamin D, alkaline phosphatase, calcium, phosphate, and parathyroid hormone levels) were obtained on all patients. Vitamin D deficiency was defined as 25-hydroxy vitamin D [25(OH)D] levels ≤35 nmol/L and insufficiency as 25(OH)D levels of 36-50 nmol/L.
RESULTS: A total of 244 children (146 male) participated in the study. Ages ranged between 3.7 and 18.8 years (mean 12.3 years). 25(OH)D levels ranged between 7.5 and 140.9 nmol/L (mean 53.9 nmol/L). Vitamin D deficiency was identified in 55 patients (22.5%), and a further 48 (19.7%) had vitamin D insufficiency. Multivariate logistic regression analysis identified polytherapy >1 AED (odds ratio [OR] 2.16, 95% confidence interval [CI] 1.07-4.36), age >12 years (OR 4.16, 95% CI 1.13-15.30), Indian ethnicity (OR 6.97, 95% CI 2.48-19.55), sun exposure time 30-60 min/day (OR 2.44, 95% CI 1.05-5.67), sun exposure time <30 min/day (OR 3.83, 95% CI 1.61-9.09), and female (OR 2.61, 95% CI 1.31-5.20) as statistically significant (p < 0.05) risk factors for vitamin D deficiency.
SIGNIFICANCE: Despite living in the tropics, a high proportion of Malaysian children with epilepsy are at risk of vitamin D deficiency. Targeted strategies including vitamin D supplementation and lifestyle advice of healthy sunlight exposure behavior should be implemented among children with epilepsy, particularly for those at high risk of having vitamin D deficiency.
Application, monitoring and adverse effects in pesticide use: The importance of reinforcement of Good Agricultural Practices (GAPs)

Leong WH, Teh SY, Hossain MM, Nadarajaw T, Zabidi-Hussin Z, Chin SY, et al.

J Environ Manage, 2020 Apr 15;260:109987.
PMID: 32090796 DOI: 10.1016/j.jenvman.2019.109987

This review intends to integrate the relevant information that is related to pesticide applications in food commodities and will cover three main sections. The first section encompasses some of the guidelines that have been implemented on management of pesticide application worldwide, such as the establishment of a value called Maximum Residue Level (MRL) through the application of Good Agricultural Practices (GAPs) into daily agricultural activities. A brief overview of the methods adopted in quantification of these trace residues in different food samples will also be covered. Briefly, pesticide analysis is usually performed in two stages: sample preparation and analytical instrumentation. Some of the preparation methods such as QuEChERs still remain as the technique of choice for most of the analytical scientists. In terms of the instrumentation such as the gas chromatography-mass spectrophotometry (GC-MS) and high performance-liquid chromatography (HPLC), these are still widely used, in spite of new inventions that are more sustainable and efficient such as the capillary electrophoresis (CE). Finally, the third section emphasizes on how pesticides can affect our health significantly whereby different types of pesticides result in different adverse health implications, despite its application benefits in agriculture in controlling pests. To date, there are limited reviews on pesticide usage in many agricultural-based nations; for the purpose of this review, Malaysia is selected to better illustrate pesticide regulations and implementation of policies. Finally, the review aims to provide an insight on how implementation of GAP and food safety assurance are inter-related and with this established correlation, to identify further measures for improvement to enable reinforcement of optimised agricultural practices specifically in these countries.
Fulltext Clinical and demographic pattern of chronic granulomatous disease (CGD) from a multicenter perspective: Malaysia's experience over 26 years

Noh LM, Latiff AHA, Ismail IH, Noah RM, Wahab AA, Hamid IJA, et al.

Allergy Asthma Clin Immunol, 2021 May 17;17(1):50.
PMID: 34001231 DOI: 10.1186/s13223-021-00551-4

BACKGROUND: A retrospective review of clinical manifestations and demographic pattern of patients diagnosed as chronic granulomatous disease (CGD) from 7 hospitals in Malaysia. An analysis of the available database would establish clinical characteristics, diagnoses and outcome including microbiologic pattern. Studying the demography allows us to document the occurrence of CGD amongst multiethnic groups and its geographical distribution for Malaysia.
METHODS: Data from the Malaysia Primary Immunodeficiency Network (MyPIN) with cases of CGD diagnosed from 1991 until 2016 were collated and analysed.
RESULTS: Twenty patients were diagnosed as CGD. Males (N = 13, 65%) outnumber females (N = 7, 35%). CGD is commonest amongst the Malays (65%) followed by the Chinese (15.0%), Indians (10.0%) and natives of Borneo (10.0%), reflecting the ethnic composition of the country. The mean age of diagnosis was 3.7 years. There was a positive family history in 40% of the cases. Abscess was the main presenting feature in 16 patients (80%) with one involving the brain. Pneumonia occurred in 10 (50%) and one with complicated bronchiectasis. Catalase-positive bacteria were the most commonly isolated pathogen with Chromobacterium violaceum predominating (N = 5, 25%) with consequent high mortality (N = 4, 80%). All CGD patients with C. violaceum infection displayed CD4 + (T helper cells) lymphopenia.
CONCLUSION: This study has shown CGD occurs in the major ethnic groups of Malaysia. To the best of our knowledge, this is the first and the largest series of chronic granulomatous disease in South East Asia which may be reflective of similar clinical pattern in the region. C. violaceum infection is associated with a higher mortality in CGD patients in Malaysia. All the CGD patients with C. violaceum infection in this patient series displayed CD4 + (T helper) lymphopenia. We recorded rare clinical manifestation of CGD viz. brain abscess and bronchiectasis.