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Influence of sublethal exposure to abamectin on the biological performance of Neoseiulus longispinosus (Acari: Phytoseiidae)

Ibrahim YB, Yee TS

J Econ Entomol, 2000 Aug;93(4):1085-9.
PMID: 10985016

Effects of sublethal exposure to abamectin on the biological performance of Neoseiulus longispinosus (Evans) were studied under ambient laboratory conditions of 28 +/- 2 degrees C and 80 +/- 15% RH with 24 h light. The red form of the twospotted spider mite, Tetranychus urticae Koch, complex (Acari: Tetranychidae), was offered as prey. The LC50 obtained from the contact bioassay at 48 h after treatment was 0.015 ppm (AI). A big change in kill for a given variation in dosage for the regression slope probably indicated that abamectin was unlikely selective. Sublethal exposure to abamectin caused a reduction in survival with the female reaching 50% mortality by the sixth day and the male 4 d later. The mean preoviposition period was extended by almost 1 d, whereas the mean oviposition period was shortened by almost 5 d causing a reduction in the mean fecundity female-1 to almost half that of the untreated females. The net reproductive rate (Ro), the intrinsic rate of increase (rm), and the finite rate of increase (lambda) of the treated females were markedly inferior. Treated males were seriously affected; the mean life span was almost half that of the untreated.
New record of an estuarine polychaete, Neanthesglandicincta (Annelida, Nereididae) on the eastern coast of Peninsular Malaysia

Fazne Ibrahim N, Shuaib Ibrahim Y, Sato M

Zookeys, 2019;831:81-94.
PMID: 31337948 DOI: 10.3897/zookeys.831.28588

An estuarine species of Nereididae (Annelida), Neanthesglandicincta (Southern, 1921) has been newly recorded on the eastern coast of Peninsular Malaysia located in the South China Sea based on 23 specimens collected from three estuaries (Tumpat, Kelantan Delta, Kelantan; Setiu Lagoon, Terengganu; Kuala Ibai, Terengganu). The morphological characteristics of the Malaysian specimens agree well with those of the previous original description and the redescription of N.glandicincta based on Indian, Myanmar and Singapore specimens. The number of paragnaths in all groups on the proboscis of our Malaysian specimens is within the range of the intraspecific variation of N.glandicincta as shown in the previous descriptions. An identification key to species of the Neanthesglandicincta species complex, which includes two morphologically similar species, is provided.
Fulltext Evaluating the perception of farmers towards pesticides and the health effect of pesticides: A cross-sectional study in the oil palm plantations of Papar, Malaysia

Bin Sulaiman SK, Ibrahim Y, Jeffree MS

Interdiscip Toxicol, 2019 Sep;12(1):15-25.
PMID: 32189983 DOI: 10.2478/intox-2019-0003

Agriculture is an important occupation in Malaysia that generates a major portion of the national revenue. Similar to the rest of the world, pesticides are used to boost agricultural production in Malaysian farms. However, chemical pesticides are associated with human health hazard and are not environment-friendly as they persist in nature for long periods of time. Therefore, pesticide use should be reduced and farmers should be trained on correct and/or alternative ways of pesticide use. In this cross-sectional study, we surveyed 19 palm oil plantations in the Sabah district of Malaysia and evaluated the perception of the workers towards pesticide use and awareness regarding the health effects post-pesticide exposure. Analysis of the survey shows that most of the workers among the 270 respondents were 30-year-old males with average education, and belonged to the low income group. Majority opined that they were aware of the health hazards of pesticide use and suffered from symptoms (with mean duration of three days) such as vomiting, diarrhea, skin irritation, and dizziness. Surprisingly, the opinion was almost equally divided on whether they perceived pesticides to be the cause of their health problems, and a major percentage did not avail medical help. Most of the workers responded that they did not receive any training in pesticide handling and used partial personal protective equipment (glasses, hats, shirt, and gloves) during working hours. Interestingly, a large percentage responded that they would not read the safety material even if it was provided. These observations clearly highlight the urgency of improving the awareness, education, and attitude of these plantation workers towards the short- and long-term effects of pesticide use. They should also be educated about alternative and eco-friendly ways of farming. Finally, the plantation management should intervene and proactively advocate the use of safe farming practices.
Fulltext Vitamin D Deficiency and Its Association With Vitamin D Receptor Gene Variants Among Malaysian Women With Hypertensive Disorders in Pregnancy: Protocol for a Nutrigenomics Study

Ibrahim Y, Basri NI, Nordin N, Mohd Jamil AA

JMIR Res Protoc, 2024 Mar 26;13:e53722.
PMID: 38530345 DOI: 10.2196/53722

BACKGROUND: Vitamin D deficiency has been associated with hypertensive disorders in pregnancy (HDP). The risk of developing HDP was reported to be further augmented among individuals with a vitamin D receptor (VDR) genetic variant. However, the reported roles of VDR variants in hypertensive disorders are inconsistent among different populations. Given the relatively higher incidence of vitamin D deficiency among Malaysian pregnant women and the high incidence of HDP in this population, we hypothesize that there may be associations between the risk of vitamin D deficiency and HDP with VDR genetic variants.
OBJECTIVE: This paper outlines the protocol for a study to determine the association of vitamin D status and VDR sequence variants among Malaysian pregnant women with HDP.
METHODS: This prospective study consists of two phases. The first phase is a cross-sectional study that will entail gathering medical records, a questionnaire survey, and laboratory testing for vitamin D status, with a planned recruitment of 414 pregnant women. The questionnaire will be utilized to assess the risk factors for vitamin D deficiency. The vitamin D status will be obtained from measurement of the vitamin D (25-hydroxyvitamin D3) level in the blood. The second phase is a case-control study involving a Malay ethnic cohort with vitamin D deficiency. Participants will be divided into two groups with and without HDP (n=150 per group). Genomic DNA will be extracted from the peripheral blood monocytes of participants using the Qiagen DNA blood kit, and VDR sequence variants will be determined using polymerase chain reaction-high-resolution melting (PCR-HRM) analysis. Sanger sequencing will then be used to sequence randomly selected samples corresponding to each identified variant to validate our PCR-HRM results. The VDR genotype and mutation frequencies of BsmI, ApaI, TaqI, and FokI will be statistically analyzed to evaluate their relationships with developing HDP.
RESULTS: As of December 2023, 340 subjects have been recruited for the phase 1 study, 63% of whom were determined to have vitamin D deficiency. In the phase 2 study, 50 and 22 subjects have been recruited from the control and case groups, respectively. Recruitment is expected to be completed by March 2024 and all analyses should be completed by August 2024.
CONCLUSIONS: The outcome of the study will identify the nonmodifiable genetic components contributing to developing vitamin D deficiency leading to HDP. This will in turn enable gaining a better understanding of the contribution of genetic variability to the development of HDP, thus providing more evidence for a need of customized vitamin D supplementation during pregnancy according to the individual variability in the response to vitamin D intake.
TRIAL REGISTRATION: ClinicalTrials.gov NCT05659173; https://clinicaltrials.gov/study/NCT05659173.
INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53722.
Fulltext Correction: Vitamin D Deficiency and Its Association With Vitamin D Receptor Gene Variants Among Malaysian Women With Hypertensive Disorders in Pregnancy: Protocol for a Nutrigenomics Study

Ibrahim Y, Basri NI, Nordin N, Mohd Jamil AA

JMIR Res Protoc, 2024 Apr 11;13:e59300.
PMID: 38603774 DOI: 10.2196/59300

[This corrects the article DOI: 10.2196/53722.].
Fulltext Experimental investigation and analytical verification of buckling of functionally graded carbon nanotube-reinforced sandwich beams

Madenci E, Özkılıç YO, Bahrami A, Aksoylu C, Asyraf MRM, Hakeem IY, et al.

Heliyon, 2024 Apr 30;10(8):e28388.
PMID: 38638992 DOI: 10.1016/j.heliyon.2024.e28388

Carbon nanotube (CNT) reinforcement can lead to a new way to enhance the properties of composites by transforming the reinforcement phases into nanoscale fillers. In this study, the buckling response of functionally graded CNT-reinforced composite (FG-CNTRC) sandwich beams was investigated experimentally and analytically. The top and bottom plates of the sandwich beams were composed of carbon fiber laminated composite layers and hard core. The hard core was made of a pultruded glass fiber-reinforced polymer (GFRP) profile. The layers of FG-CNTRC surfaces were reinforced with different proportions of CNT. The reference sample was made of only a pultruded GFRP profile. In the study, the reference sample and four samples with CNT were tested under compression. The largest buckling load difference between the reference sample and the sample with CNT was 37.7%. The difference between the analytical calculation results and experimental results was obtained with an approximation of 0.49%-4.92%. Finally, the buckling, debonding, interlaminar cracks, and fiber breakage were observed in the samples.
Fulltext Biorational control programme for the German cockroach (Blattaria: Blattellidae) in selected urban communities

Shahraki G, Bin Ibrahim Y, Noor HM, Rafinejad J, Shahar MK

Trop Biomed, 2010 Aug;27(2):226-35.
PMID: 20962720 MyJurnal

This study assessed the effectiveness of a biorational control approach using 2% hydramethylnon gel bait on German cockroaches, Blattella germanica (L.) in some residential and hospital buildings in South Western Iran. In total, three buildings consisting of 150 apartment units and 101 hospital units were monitored weekly via sticky trap for German cockroach infestations over a period of eight months. These infested units were randomly subjected to intervention and control treatments. Pamphlets and posters were provided and lectures were given to support the educational programmes as a tactic of the biorational system. Survey on cockroach index for intervention units showed 67-94% recovery to achieve clean level of infestation for intervention units of the residential buildings and 83% for the hospital. Mean percentage reductions for treatment groups throughout the 15-week treatment period were 76.8% for the residential buildings and 88.1% for the hospital, showing significant differences compared to the control groups. Linear regression of infestation rates were recorded weekly after treatment and their negative slope for treatment groups substantiated significant reductions for interventions. The results of this study showed that biorational control method, using gel bait, educational programmes and sanitation, is an effective way to manage German cockroach infestation.
Trypanosuppressive effects of Kolaviron may be associated with down regulation of Trypanothione reductase in Trypanosoma congolense infection

Timothy MR, Ibrahim YKE, Muhammad A, Chechet GD, Aimola IA, Mamman M

Trop Biomed, 2021 Mar 01;38(1):94-101.
PMID: 33797530 DOI: 10.47665/tb.38.1.016

Trypanothione reductase is a key enzyme that upholds the redox balance in hemoflagellate protozoan parasites such as T. congolense. This study aims at unraveling the potency of Kolaviron against trypanothione reductase in T. congolense infection using Chrysin as standard. The experiment was performed using three different approaches; in silico, in vitro and in vivo. Kolaviron and Chrysin were docked against trypanothione reductase, revealing binding energies (-9.3 and -9.0 kcal/mol) and Ki of 0.211μM and 0.151μM at the active site of trypanothione reductase as evident from the observed strong hydrophobic/hydrogen bond interactions. Parasitized blood was used for parasite isolation and trypanothione reductase activity assay using standard protocol. Real-time PCR (qPCR) assay was implored to monitor expression of trypanothione reductase using primers targeting the 177-bp repeat satellite DNA in T. congolense with SYBR Green to monitor product accumulation. Kolaviron showed IC50 values of 2.64μg/ml with % inhibition of 66.78 compared with Chrysin with IC50 values of 1.86μg/ml and % inhibition of 53.80. In vivo studies following the administration of these compounds orally after 7 days post inoculation resulted in % inhibition of Chrysin (57.67) and Kolaviron (46.90). Equally, Kolaviron relative to Chrysin down regulated the expression trypanothione reductase gene by 1.352 as compared to 3.530 of the infected group, in clear agreement with the earlier inhibition observed at the fine type level. Overall, the findings may have unraveled the Kolaviron potency against Trypanosoma congolense infection in rats.