Power Comparisons of the Rician and Gaussian Random Fields Tests for Detecting Signal from Functional Magnetic Resonance Images

The functional magnetic resonance imaging (fMRI) data are known to be complex valued. The real and imaginary components are assumed to be independently and normally distributed. After image reconstructions, these components are separated into two components, namely magnitude and phase. Usually, only the magnitude component is used in the analysis and it is assumed to be normally, or Gaussian, distributed. The statistical analysis of fMRI data using random field theory also assumed that the data are Gaussian distributed. However, the magnitude component is actually Rician distributed and no work has been found on the Rician random field. In this dissertation, Rician random field was defined, in general, and simulated in a two-dimensional image. A new test statistic to detect a signal from the functional magnetic resonance image, Rmax, which follows the Rician random field, was introduced. The power of Rmax was calculated using Monte Carlo simulation, and compared to the Gaussian test statistic, Zmax. The effects of factors known to influence the power of Rmax, namely amplitude, scale and location of the signal, were also studied. The amplitude was shown to be the most influencing factor on the power of Rmax, followed by the scale of the signal. The location of the signal did not seem to affect the power of the Rmax. However, the power of Rmax did not outperform the power of Zmax. Future studies are required to provide more information on the properties and behaviors of Rmax

Falls risk screening tools intended to reduce fall risk among independent community-dwelling older adults : A systematic review

Aims: The aim of this study is to evaluate an evidence-based fall risk screening tool to predict the risk of falls suitable for independent community-dwelling older adults guided by the World Health Organization's International Classification of Functioning, Disability and Health (WHO-ICF) components, and to examine the reliability and validity of the fall risk screening tool to predict fall risks, and to examine the feasibility of tools among independent community-dwelling older adults. Methods: A systematic literature search guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was performed using the EBSCOHost® platform, ScienceDirect, Scopus and Google Scholar between July and August 2021. Studies from January 2010 to January 2021 were eligible for review. Nine articles were eligible and included in this systematic review. The risk of bias assessment used the National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies. The WHO-ICF helped to guide the categorization of fall risk factors. Results: Seven screening tools adequately predicted fall risk among communitydwelling older adults. Six screening tools covered most of the components of the WHO-ICF, and three screening tools omitted the environmental factors. The modified 18-item Stay Independent Brochure demonstrated most of the predictive values in predicting fall risk. All tools are brief and easy to use in community or outpatient settings. Conclusion: The review explores the literature evaluating fall risk screening tools for nurses and other healthcare providers to assess fall risk among independent community-dwelling older adults. A fall risk screening tool consisting of risk factors alone might be able to predict fall risk. However, further refinements and validations of the tools before use are recommended

Occurrence of K1 and K2 serotypes and genotypic characteristics of extended spectrum β-lactamases-producing Klebsiella pneumoniae isolated from selected hospitals in Malaysia

Objective: To determine the distribution, phenotypic and genetic background of extended spectrum β-lactamases (ESBL)-producing Klebsiella (K.) pneumoniae clinical isolates associated with K1 and K2 serotypes in two selected hospitals in Malaysia. Methods: A total of 192 K. pneumoniae isolates were collected and subjected to antibiotic susceptibility, hypermucoviscosity test and multiplex PCR to detect the presence of K1- and K2-serotype associated genes. Multilocus sequence typing (MLST) was performed on ESBL-producing K. pneumoniae isolates presented with K1 and K2 serotypes, followed by phylogenetic analysis. Results: A total of 87 out of 192 (45.3%) of the K. pneumoniae isolates collected were ESBL producers. However, only 8.3% (16/192) and 10.9% (21/192) of the total isolates were detected to carry K1- and K2-serotype associated genes, respectively. Statistical analysis showed that K1 and K2 capsular serotypes were not significantly associated with ESBL phenotype (P=0.196). However, they were significantly associated with hypervirulent, as demonstrated by the positive string test (P<0.001). MLST analysis revealed that ST23 as the predominant sequence type (ST) in the K1 serotype, while the ST in the K2 serotype is more diverse. Conclusions: Although the occurrence of ESBL-producing isolates among the hypervirulent strains was low, their coexistence warrants the need for continuous surveillance. MLST showed that these isolates were genetically heterogeneous

Harvested locations influence the total phenolic content, antioxidant levels, cytotoxic, and anti-inflammatory activities of stingless bee honey

Kelulut honey (KH) is a natural product-derived food produced by stingless bees of Trigona or Meliponine species. Several studies have shown that the geographical origin of honey significantly affects its pharmacological properties. Thus, this study aims to characterise the pharmacological properties of KH harvested from different geographical locations. The total phenolic content (TPC), antioxidant levels, cytotoxic, and anti-inflammatory activities of pure KH harvested from three different locations (Sarawak, Pahang and Selangor) were compared. Among the samples, KH harvested from Selangor exhibited the highest TPC, antioxidant levels, and cytotoxic activity against MDA-MB-231 and MCF-7 cells, followed by KH harvested from Sarawak and Pahang. The IC50 of MCF-7 cells treated with KH harvested from Selangor was at least 2-fold lower than the IC50 of MDA-MB-231 cells, suggesting that KH is more cytotoxic to oestrogen receptor (ER)- and progesterone receptor (PR)-positive (MCF-7) compared to triple-negative (MDA-MB-231) breast cancer cells. Two non-cytotoxic concentrations (1% and 0.5%; v/v) were selected for the anti-inflammatory assay using lipopolysaccharide (LPS)-induced RAW 264.7 cells. KH harvested from Selangor and Pahang (at a concentration of 1%; v/v) significantly inhibited nitric oxide (NO) production in LPS-induced RAW 264.7 cells compared to control cells. These findings provide evidence that the geographical origin of KH may indeed influence its pharmacological properties. Our data suggest that KH harvested from Selangor has a better quality compared to KH harvested from Pahang and Sarawak based on its high TPC, antioxidant levels and anti-inflammatory activity. Furthermore, it exhibits in vitro anticancer potential in breast cancer cell lines

Multiple microRNA signature panel as promising potential for diagnosis and prognosis of head and neck cancer

MicroRNAs are small non-coding RNA that regulate gene expressions of human body. To date, numerous studies have reported that microRNAs possess great diagnostic and prognostic power in head and neck cancer and had governed a lot of attention. The factor for the successfulness of miRNAs in these aspects is due to cancer being fundamentally tied to genetic changes, which are regulated by these miRNAs. Head and neck cancer, leading the world record for cancer as number sixth, is caused by multiple risk factors such as tobacco consumption, alcohol consumption, dietary factors, ethnicity, family history, and human papilloma virus. It derives at locations such as oral cavity, pharynx, larynx, paranasal sinus and salivary gland and have high rate of mortality with high recurrence rate. Besides, head and neck cancer is also usually having poor prognosis due to its asymptomatic nature. However, this diagnostic and prognostic power can be further improved by using multiple panels of miRNA as a signature or even combined with TNM staging system to obtain even more remarkable results. This is due to multiple factors such as tumour heterogeneity and components of the tumour which may affect the composition of miRNAs. This review covers the examples of such miRNA signatures, compare their diagnostic and prognostic powers, discuss some controversial roles of unreported miRNAs, and the molecular mechanisms of the miRNAs in gene targeting and pathways

Construction and investigation of plasmid-induced effects on growth of GFP-expressing Salmonella strains

Background: Bacteria such as the Salmonella species had been extensively studied not only for its mechanism of pathogenicity, but for its beneficial utilisation in bacterial-mediated tumour therapy. Genetically modified bacterial strain, BDLA Salmonella Agona (BDLA S. Agona) had shown great promise as tumour targeting and suppressing agent. By, constructing green fluorescent protein (GFP) expressing of this strain, it would be beneficial as it could be used to further study the interaction of the BDLA S. Agona strain with various cancerous cells and the host at the systemic level. However, GFP plasmid-induced strains may exhibit growth defects, and this was investigated in this study. Methods: The GFP-transformed Salmonella strains were constructed, and the replication rate of the strains were investigated using the BacterioScan™ 216R instrument. The replication rate between the strains was compared from the 24-hour data collected and analysed as growth curves. The 24-hour growth curves were constructed using the Log CFU/mL and OD650 data collected by the instrument. Results: It was observed from the growth curves that the transformation of the GFP plasmid into different Salmonella strains did not affect the replication rate of the bacteria. Discussion and Conclusion: This finding answers the objective of the study, and it was concluded that incorporation of the GFP plasmid does not cause any negative effect on bacterial growth. GFP-transformed Salmonella, specifically the BDLA S. Agona strain, could be utilised as a powerful tool for future studies on the mechanism of tumour suppression and real-time in vivo biodistribution of the strain

Psychometric evaluation of the Protection Motivation Theory scale in assessing fall protection motivation among older adults to reduce fall risk

Abstract Background Protection Motivation Theory could be another potential and good framework that addresses essential elements in a behavioural change leading to positive fall protective behaviours. The positive behavioural change could reduce the risk of falls and improve the quality of life of the older community. The study aims to evaluate the reliability and validity of the culturally adapted Protection Motivation Theory scale for older adults' fall protection motivation or protective behaviours to reduce fall risk. Methods A cross-sectional study was conducted to establish a psychometric instrument validation. A total of 389 participants aged 55 years and above were included. The study was conducted in Sarawak, Malaysia, from November 2021 to January 2022 in two phases, translation of the PMT Scale, cross-cultural adaptation, face validation and pre-testing of the PMT Scale. The participants were selected using multistage random sampling in a primary healthcare clinic. Data entry and statistical analysis were performed using IBM SPSS version 26 for exploratory factor analysis and SmartPLS version 3.3.7 for confirmatory factor analysis using partial least square structural equation modelling. Results The Kaiser–Meyer–Olkin value was 0.760, Bartlett's sphericity test was significant and the total variance explained was 61%. It identified 31 items within eight dimensions of the Protection Motivation Theory scale. The Higher Order Constructs' measurement model indicates that the convergent and discriminant validity were established (Cronbach's alpha and composite reliability: ≥ 0.740; average variance extracted: 0.619 to 0.935 and Henseler's Heterotrait-Monotrait criterion for all constructs' discriminant validity: < 0.9). Test–retest for the intraclass correlation coefficient was 0.745. The model's coefficient of determination demonstrated R2 = 0.375. Conclusion Overall, the Protection Motivation Theory Scale has established its reliability and validity for assisting older adults in the community. The Protection Motivation Theory Scale could be used in fall prevention interventions by promoting fall protective behaviours to reduce fall risk among community-dwelling older adults. The scale could assist healthcare providers in assessing the intention of older adults to use fall protective behaviours to reduce fall risk and serve as an alternative reference in developing fall prevention education in a fall prevention strategy

Physiological response and impact of COVID-19 pandemic among Malaysian citizens: a cross-sectional study

Introduction: Studies have shown that staying at home for prolonged periods of crisis can pose a significant challenge to individuals and affect their mental health. Hence, this study was conducted to identify the susceptible subgroups among Malaysian citizens that are prone to mental health problems during the lockdown period of the COVID-19 pandemic and its association with sociodemographic factors. Methods: The mental health status was assessed using the Depression, Anxiety, and Stress Scale -21 (DASS-21) questionnaire. The survey link was distributed online between October and December 2020. Results: Of 637 respondents, one-third experienced mild to extremely severe depression and anxiety (31.1 and 35.1, respectively). Female respondents (odds ratio = 1.516, 95 confidence interval (CI) 1.057-2.172) were 1.5 times more likely to experience mild to severe depression than male respondents. Unmarried and divorced respondents were 2.1 times more prone to experience mild to severe depression than married respondents. A significant association was also found between employment status and age with depression symptoms among the respondents. For anxiety, a significant association was observed between the age group with mild to severe anxiety symptoms. Marital status, age, and employment status were socio-demographic factors significantly impacting stress levels. Conclusion: According to our findings, females, individuals aged 18-30 years old, students, unmarried and divorced respondents were more susceptible to mental health problems, suggesting that mental health support shall also be provided for these vulnerable groups during the COVID-19 crisis

Insomnia and depression levels among Malaysian undergraduate students in the Faculty of Medicine and Health Sciences (FMHS), Universiti Putra Malaysia (UPM) during Movement Control Order (MCO).

Rapid outbreak of coronavirus disease 2019 has caused the implementation of the movement control order (MCO) which aimed to reduce the spread in Covid-19 infections. While some may find it easy to adjust to the new norm, others found it difficult to switch from their normal routines and habits as according to the MCO SOP. This resulted in a more frequent insomnia and depression that subsequently impacted their mental health. Insomnia and depression levels are examined in this study as they relate to the Covid-19 Pandemic and the MCO among Malaysian undergraduate health sciences students at the Faculty of Medicine and Health Sciences, UPM. Random sampling methods were utilised with consideration of inclusion and exclusion criteria. The Patient Health Questionnaire-9 (PHQ-9) and the Insomnia Severity Index (ISI) were the instrument packages used in this investigation. An internet platform was used to distribute the questionnaire. Based on the results, it is concluded that depression and insomnia are significantly correlated, with a p-value of 0.05. This study also revealed the link between the severity of insomnia and the severity of depression among UPM students studying health sciences. The percentage of students with depression and insomnia was rather high (54.9% and 33.9%, respectively), and this occurred during the second wave of Covid-19 cases in Malaysia