Displaying publications 61 - 80 of 526 in total

Abstract:
Sort:
  1. The effects of raw material particles size, types of solvents and solvent-to-solid ratio on the yield of rotenone extracted from derris elliptica roots
    Saiful Izwan Zubairi, Mohamad Roji Sarmidi, Ramlan Abdul Aziz
    Sains Malaysiana, 2014;43:707-713.
    Currently, bio-pesticide is relatively harmless to human and environment and thus desirable for its use in the control of insect vectors. Bio-pesticide has been increasingly important in both scale commercial agriculture and small plot, subsistence farming. One of the sources for bio-pesticide is ‘tuba’ plant, known as Derris elliptica. Derris elliptica contains bio-active compounds known as rotenone (C23H33O6) which is harmless to plants, highly toxic to many insects and relatively innocuous to mammals. The study was carried out to investigate the appropriate processing parameters with the aimed to acquire high yield of rotenone (mg) and concentration (mg/mL) of the exhaustive extraction process by evaluating the kinetics of the normal soaking extraction (NSE) method. The raw plants were collected from Kota Johor Lama, Johor and sorted to collect the root. The roots were sorted into 2 types of raw material particles size (mm in diameter) prior to the extraction process. Rotenone from the root part was extracted by using a NSE method at ambient temperature of 27±1oC. Three types of solvents and 2 solvent-to-solid ratios were utilized throughout the extraction process. The extraction was carried out for 50 h and the fractions of the liquid crude extract were collected for each interval time (2 h/mL/fraction) and further cleaned up to remove any fine debris prior to the determination of rotenone content (mg) and its concentration (mg/mL) via reverse-phase high performance liquid chromatography (RP-HPLC). From the kinetics result obtained, it was found that the fine Derris elliptica roots with particles size of 0.5 - 2 mm in diameter and solvent-to-solid ratio of 10 mL/g of acetone solvent system were considered the best processing parameters to procure high yield of rotenone and its concentration.
  2. A thermal degradation (Thermolysis) study of rotenone extracted from derris elliptica roots using reverse-phase high performance liquid chromatography (RP-HPLC)
    Saiful Irwan Zubairi, Mohamad Roji Sarmidi, Ramlan Abdul Aziz
    Sains Malaysiana, 2015;44:121-126.
    Bio-pesticides are becoming increasingly important as pest management tools in various cropping systems in the tropics essentially to remedy problems associated with the indiscriminate use of ‘hard’ and non-environmental friendly inorganic pesticide. In these past few decades, many bio-pesticidal products, both microbial-based (bacteria, fungi, microsprodia, entomopathogenic nematodes and viruses) and plant-based botanicals (rotenone and azadiracthin) have been studied for their use against insect pests in the tropics. In this study, the effects of the concentration process with respect to the yield of rotenone (mg) and its concentration (mg/mL) are presented extensively. The raw plants were collected from Kota Johor Lama, Johor and sorted to obtain the roots and stems. Only the roots and stems were utilized as raw materials of the extraction process. The rotenone from roots and stems was extracted using the normal soaking extraction (NSE) at 28 to 30oC with 95% (v/v) of acetone as a solvent and the solvent-to-solid ratio of 10 mL/g. The extraction was carried out for 24 h. Next, the liquid crude extract was concentrated using the rotary evaporator at 50oC and 80 mbar of vacuum pressure to remove approximately 90% of solvent. The fractions of the liquid crude extract were collected (15 min/mL/fraction), diluted (1/100 with acetone) and cleaned up (to remove any fine debris) prior to determination of rotenone content (mg) and concentration (mg/mL) by using the reverse-phase high performance liquid chromatography (RP-HPLC). Finally, the results showed that there was a significant effect of thermal degradation or dissipation of rotenone content at higher operating temperature (greater than 40oC) with a rapid rotenone reduction for the first 15 min of exposure. The possibilities for better exploitation and identification of the effective operating parameters based on the above mentioned results will be perhaps discussed in the future.
  3. The foraging tactics of chestnut-winged babbler (stachyris erythroptera) and abbott’s babbler (malacocincla abbotti) in a lowland rainforest, Malaysia
    Mohammad Saiful Mansor, Rosli Ramli, Mohammad Saiful Mansor, Shahrul Anuar Mohd Sah
    Sains Malaysiana, 2015;44:687-692.
    Foraging pattern of Chestnut-winged Babbler (Stachyris erythroptera) and Abbott’s Babbler (Malacocincla abbotti) was
    studied in Lenggong Valley, Perak from July 2010 until July 2011. The study examines the patterns of foraging height,
    foraging substrates and attack manoeuvres of two babbler species (Family: Timaliidae), to explain how these trophically
    similar species can coexist in the same habitat; a central question in ecology. Information on the foraging height, foraging
    substrate and attack manoeuvres was collected independently for each foraging bird. Principal component analysis and
    Pearson’s correlation analysis showed that these two species used similar proportion of foraging height (>0-2 m above
    the ground) and foraging substrate (dead leaves), but differed in the use of attack manoeuvres. The Chestnut-winged
    babbler used primarily stretching manoeuvre, whereas the Abbott’s babbler used primarily gleaning manoeuvre. This
    niche separation allowed these species to coexist in the same area, thus follows the Gause’ Law of competitive exclusion,
    that states two species occupying the same niches will not coexist forever.
  4. Chemical composition of volatile oils of Aquilaria malaccensis (Thymelaeaceae) from Malaysia
    Tajuddin SN, Yusoff MM
    Nat Prod Commun, 2010 Dec;5(12):1965-8.
    PMID: 21299133
    Volatile oils of Aquilaria malaccensis Benth. (Thymelaeaceae) from Malaysia were obtained by hydrodistillation and subjected to detailed GC-FID and GC/MS analyses to determine possible similarities and differences in their chemical composition in comparison with the commercial oil. A total of thirty-one compounds were identified compared with twenty-nine identified in the commercial oil. The major compounds identified were 4-phenyl-2-butanone (32.1%), jinkoh-eremol (6.5%) and alpha-guaiene (5.8%), while the major compounds in the commercial oil were alpha-guaiene (10.3%), caryophellene oxide (8.6%), and eudesmol (3.2%). The results of the present study showed that more than nine sesquiterpene hydrocarbons were present, which is more than previously reported. Analysis also showed that the number of oxygenated sesquiterpenes in this study were much less than previously reported. Among the compounds detected were alpha-guaiene, beta-agarofuran, alpha-bulnesene, jinkoh-eremol, kusunol, selina-3,11-dien-9-one, oxo-agarospirol and guaia-1 (10), 11-dien-15,2-olide.
  5. From forest landscape to agricultural landscape in the developing tropical country of Malaysia: pattern, process, and their significance on policy
    Abdullah SA, Hezri AA
    Environ Manage, 2008 Nov;42(5):907-17.
    PMID: 18626684 DOI: 10.1007/s00267-008-9178-3
    Agricultural expansion and deforestation are spatial processes of land transformation that impact on landscape pattern. In peninsular Malaysia, the conversion of forested areas into two major cash crops--rubber and oil palm plantations--has been identified as driving significant environmental change. To date, there has been insufficient literature studying the link between changes in landscape patterns and land-related development policies. Therefore, this paper examines: (i) the links between development policies and changes in land use/land cover and landscape pattern and (ii) the significance and implications of these links for future development policies. The objective is to generate insights on the changing process of land use/land cover and landscape pattern as a functional response to development policies and their consequences for environmental conditions. Over the last century, the development of cash crops has changed the country from one dominated by natural landscapes to one dominated by agricultural landscapes. But the last decade of the century saw urbanization beginning to impact significantly. This process aligned with the establishment of various development policies, from land development for agriculture between the mid 1950s and the 1970s to an emphasis on manufacturing from the 1980s onward. Based on a case study in Selangor, peninsular Malaysia, a model of landscape pattern change is presented. It contains three stages according to the relative importance of rubber (first stage: 1900--1950s), oil palm (second stage: 1960s--1970s), and urban (third stage: 1980s--1990s) development that influenced landscape fragmentation and heterogeneity. The environmental consequences of this change have been depicted through loss of biodiversity, geohazard incidences, and the spread of vector-borne diseases. The spatial ecological information can be useful to development policy formulation, allowing diagnosis of the country's "health" and sustainability. The final section outlines the usefulness of landscape analysis in the policy-making process to prevent further fragmentation of the landscape and forest loss in Malaysia in the face of rapid economic development.
  6. Fulltext The economically important thrips from Malaysia, with a key to species (Thysanoptera, Thripinae)
    Ng YF, Zaimi JS
    Zookeys, 2018.
    PMID: 30613175 DOI: 10.3897/zookeys.810.28457
    An illustrated key is provided to the economically important Thripinae (Thysanoptera) of Malaysia, together with a checklist and information on hosts and distributions. Information about the diversity and pest status for these Thripinae is provided, together with the prominent character states that are useful for recognising each species.
  7. Fulltext The influence of habitat structure on bird species composition in lowland malaysian rain forests
    Mansor MS, Sah SA
    Trop Life Sci Res, 2012 May;23(1):1-14.
    PMID: 24575221 MyJurnal
    Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild.
  8. Outcome of tracheostomy among COVID-19 patients in a tertiary hospital setting: Our experience
    Razak I, Hari K, Syakirah Z, Saiful M, Shahrul H
    Med J Malaysia, 2023 Jan;78(1):35-38.
    PMID: 36715189
    INTRODUCTION: The COVID-19 pandemic is unprecedented. Amongst those who contracted COVID-19, a number required intubation and prolonged ventilation. This increased the number of ventilated patients in the hospital and increased the requirement for tracheostomy of severe COVID-19 patients. Our objective is to study the outcome of patients with COVID-19 who underwent tracheostomy.

    MATERIALS AND METHODS: This study is a novel retrospective study in a tertiary centre in Malaysia. Case notes of COVID- 19 patients who underwent tracheostomy in Hospital Ampang were collected using the electronic Hospital Information System. Data were analysed using the SPSS system.

    RESULTS: From a total of 30 patients, 15 patients survived. All patients underwent either open or percutaneous tracheostomy. The median age is 53 (range: 28-69) with a significant p-value of 0.02. Amongst comorbidities, it was noted that diabetes mellitus was significant with a p-value of 0.014. The median time from the onset of COVID-19 to tracheostomy is 30 days. The median duration of intensive care unit (ICU) stay is 30.5 days, with the median duration of hospital length of stay of 44 days (p = 0.009 and <0.001, respectively). No complications that contributed to patient death were found. Survivors had a median of 29.5 days from tracheostomy to oxygen liberation.

    CONCLUSION: Tracheostomy in COVID-19 patients that requires prolonged ventilation is unavoidable. It is a safe procedure and mortality is not related to the procedure. Mortality is primarily associated with COVID-19.

  9. Prevalence of plasmid-mediated qnr determinants and gyrase alteration in Klebsiella pneumoniae isolated from a university teaching hospital in Malaysia
    Saiful Anuar AS, Mohd Yusof MY, Tay ST
    Eur Rev Med Pharmacol Sci, 2013 Jul;17(13):1744-7.
    PMID: 23852897
    The ciprofloxacin resistance of Klebsiella (K.) pneumoniae is mediated primarily through alterations in type II topoisomerase (gyrA) gene and plasmid-mediated quinolone resistance-conferring genes (qnr). This study aimed to define the prevalence of plasmid-mediated quinolone resistance-conferring genes (qnr) and type II topoisomerase (gyrA) alterations of a population of ciprofloxacin-resistant (n = 21), intermediate (n = 8), and sensitive (n = 18) K. pneumoniae isolates obtained from a teaching hospital at Kuala Lumpur, Malaysia.
  10. Fulltext Ancient schwannoma of the conus medullaris
    Saiful Azli MN, Abd Rahman IG, Md Salzihan MS
    Med J Malaysia, 2007 Aug;62(3):256-8.
    PMID: 18246922 MyJurnal
    Cystic spinal or ancient schwannoma is a rare form of intradural tumour especially in the conus medullaris region. Due to its indolent behavior and benign course, the diagnosis of schwannoma is always a challenge and the imaging findings can be misleading. Our patient presented with chronic mild sciatica pain without any other neurological symptom. MRI of the spine showed intradural tumour located at the conus medullaris region with nerves compression and was reported as ependymoma. L3-L5 laminectomy and total excision of tumour was performed without any neurological complication. We concluded that ancient schwannoma of the conus medullaris is a rare benign tumour that can present with minimal non-specific neurological symptom that lead to misdiagnosis. Radical tumour excision is safe with an excellent outcome.
  11. Fulltext Chemopreventive Effects of Germinated Rough Rice Crude Extract in Inhibiting Azoxymethane-Induced Aberrant Crypt Foci Formation in Sprague-Dawley Rats
    Saki E, Saiful Yazan L, Mohd Ali R, Ahmad Z
    Biomed Res Int, 2017;2017:9517287.
    PMID: 28116312 DOI: 10.1155/2017/9517287
    Chemoprevention has become an important area in cancer research due to low success rate of current therapeutic modalities. Diet plays a vital role in the etiology of cancer. This research was carried out to study the chemopreventive properties of germinated rough rice (GRR) crude extract in Sprague-Dawley rats induced with azoxymethane. Germination of rough rice causes significant changes in several chemical compositions of presently bioactive compounds. These compounds may prevent or postpone the inception of cancer. Fifty male Sprague-Dawley rats (6 weeks of age) were randomly divided into 5 groups which were (G1) induced with azoxymethane (AOM) and not given GRR (positive control), (G2) induced with AOM and given 2000 mg/kg GRR, (G3) induced with AOM and given 1000 mg/kg GRR, (G4) induced with AOM and given 500 mg/kg GRR, and (G5) not induced with AOM and not given GRR crude extract (negative control). To induce colon cancer, rats received two IP injections of AOM in saline (15 mg/kg) for two subsequent weeks. Organs were removed and weighed. Aberrant crypt foci (ACF) were evaluated histopathologically. β-Catenin expressions were determined by Western blot. Treatment with 2000 mg/kg GRR crude extract not only resulted in the greatest reduction in the size and number of ACF but also displayed the highest percentage of nondysplastic ACF. Treatment with 2000 mg/kg GRR also gave the lowest level of expression in β-catenin. Thus, GRR could be a promising dietary supplement for prevention of CRC.
  12. Fulltext A review on current nanomaterials and their drug conjugate for targeted breast cancer treatment
    Lee JJ, Saiful Yazan L, Che Abdullah CA
    Int J Nanomedicine, 2017;12:2373-2384.
    PMID: 28392694 DOI: 10.2147/IJN.S127329
    Breast cancer is the most common malignancy worldwide, especially among women, with substantial after-treatment effects. The survival rates of breast cancer have decreased over the years even with the existence of various therapeutic strategies, specifically, chemotherapy. Clinical drugs administered for breast cancer appear to be non-targeting to specific cancer sites leading to severe side effects and potentially harming healthy cells instead of just killing cancer cells. This leads to the need for designing a targeted drug delivery system. Nanomaterials, both organic and inorganic, are potential drug nanocarriers with the ability of targeting, imaging and tracking. Various types of nanomaterials have been actively researched together with their drug conjugate. In this review, we focus on selected nanomaterials, namely solid-lipid, liposomal, polymeric, magnetic nanoparticles, quantum dots, and carbon nanotubes and their drug conjugates, for breast cancer studies. Their advantages, disadvantages and previously conducted studies were highlighted.
  13. Fulltext Potential implications of GRP58 expression and susceptibility of cervical cancer to cisplatin and thymoquinone-based therapy
    Hafiza WA, Latifah SY
    Onco Targets Ther, 2014;7:1375-87.
    PMID: 25143744 DOI: 10.2147/OTT.S62928
    A new therapeutic approach of looking at the expression of glucose-regulated protein (GRP) 58 as an indication of cisplatin sensitivity may eradicate fruitless treatment and side effects in patients with cervical cancer. Thymoquinone, the bioactive compound in Nigella sativa, has been reported to have an antiproliferative effect on cervical cancer cells. This study compared the cytotoxic effects of cisplatin, a drug commonly used in the treatment of cervical cancer, and thymoquinone in cervical cancer (HeLa and SiHa) cell lines by 3-(4,5-Dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and measured GRP58 expression in the cells by quantitative real-time polymerase chain reaction and Western blotting. Cisplatin had higher antiproliferative activity towards the cervical cancer cell lines than thymoquinone in a dose-dependent and time-dependent manner. However, cisplatin was more toxic to normal 3T3 and Vero cell lines than thymoquinone. The half maximal inhibitory concentration (IC50) of cisplatin in HeLa and SiHa cells at 72 hours was 13.3±2.52 μM and 19.5±2.12 μM, respectively. Meanwhile, the IC50 of thymoquinone in HeLa and SiHa cells was 29.57±5.81 μM and 23.41±1.51 μM, respectively (P<0.05). A significant correlation was found between the cytotoxicity of cisplatin and expression of GRP58, but this relationship was not significant for thymoquinone. Therefore, the response of cervical cancer cells to cisplatin can be predicted on the basis of GRP58 expression.
  14. Fulltext Comparative analysis of Mafriwal (Bos taurus × Bos indicus) and Kedah Kelantan (Bos indicus) sperm proteome identifies sperm proteins potentially responsible for higher fertility in a tropical climate
    Ashrafzadeh A, Nathan S, Karsani SA
    Int J Mol Sci, 2013;14(8):15860-77.
    PMID: 23903046 DOI: 10.3390/ijms140815860
    The fertility of zebu cattle (Bos indicus) is higher than that of the European purebred (Bos taurus) and crossbred (Bos taurus × Bos indicus) cattle in tropical areas. To identify proteins related to the higher thermo-tolerance and fertility of Zebu cattle, this study was undertaken to identify differences in sperm proteome between the high fertile Malaysian indigenous zebu cattle (Kedah Kelantan) and the sub-fertile crossbred cattle (Mafriwal). Frozen semen from three high performance bulls from each breed were processed to obtain live and pure sperm. Sperm proteins were then extracted, and two-dimensional gel electrophoresis performed to compare proteome profiles. Gel image analysis identified protein spots of interest which were then identified by liquid chromatography mass spectrometry quadrupole time-of-flight (LC MS/MS Q-TOF). STRING network analysis predicted interactions between at least 20 of the identified proteins. Among the identified proteins, a number of motility and energy related proteins were present in greater abundance in Kedah Kelantan. Sperm motility evaluation by Computer Assisted Semen Analysis (CASA) confirmed significantly higher motility in Kedah Kelantan. While results from this study do identify proteins that may be responsible for the higher fertility of Kedah Kelantan, functional characterization of these proteins is warranted to reinforce our understanding of their roles in sperm fertility.
  15. Lethal hemorrhage from a ureteric-arterial-enteric fistula diagnosed by postmortem CT angiography
    Rashid SN, Bouwer H, O'Donnell C
    Forensic Sci Med Pathol, 2012 Dec;8(4):430-5.
    PMID: 22477359 DOI: 10.1007/s12024-012-9332-3
    Fistula formation following pelvic surgery and radiotherapy, including ureteric-arterial fistulas (UAF), is well documented, however, ureteric-arterial-enteric fistula is extremely rare. Conventional autopsy is usually required for the definitive diagnosis of pelvic vascular fistulas although an accurate diagnosis can still be complicated and challenging. The role of post-mortem computed tomography (PMCT) as an adjunct to conventional autopsy is well documented in the literature. One of the limitations of PMCT is the diagnosis of vascular conditions. Post-mortem computed tomography angiography (PMCTA) is a recently introduced technique that can assist in detecting such pathology. We present a case of post-radiotherapy ureteric-arterial-enteric fistula presenting as massive rectal and vaginal bleeding diagnosed prior to autopsy on PMCTA. The role of PMCTA in the diagnosis of such a UAF has not previously been reported in the literature.
  16. Thymoquinone from Nigella sativa was more potent than cisplatin in eliminating of SiHa cells via apoptosis with down-regulation of Bcl-2 protein
    Ng WK, Yazan LS, Ismail M
    Toxicol In Vitro, 2011 Oct;25(7):1392-8.
    PMID: 21609759 DOI: 10.1016/j.tiv.2011.04.030
    Thymoquinone (TQ), the active constituent of Nigella sativa or black cumin exhibited cytotoxic effects in several cancer cell lines. In this study, the cytotoxicity of TQ in human cervical squamous carcinoma cells (SiHa) was investigated. TQ was cytotoxic towards SiHa cells with IC50 values of 10.67 ± 0.12 and 9.33 ± 0.19 μg/mL as determined by MTT assay and trypan blue dye exclusion test, respectively, after 72 h of incubation. TQ was more cytotoxic towards SiHa cells compared to cisplatin. Interestingly, TQ was less cytotoxic towards the normal cells (3T3-L1 and Vero). Cell cycle analysis performed by flowcytometer showed a significant increase in the accumulation of TQ-treated cells at sub-G1 phase, indicating induction of apoptosis by the compound. Apoptosis induction by TQ was further confirmed by Annexin V/PI and AO/PI staining. Significant elevation of p53 and down-regulation of the anti-apoptotic Bcl-2 protein was found in the treated cells, without any changes in the expression of the pro-apoptotic Bax protein. In conclusion, thymoquinone from N. sativa was more potent than cisplatin in elimination of SiHa cells via apoptosis with down-regulation of Bcl-2 protein.
  17. Evaluation of kappa carrageenan as potential carrier for floating drug delivery system: Effect of pore forming agents
    Selvakumaran S, Muhamad II, Abd Razak SI
    Carbohydr Polym, 2016 Jan 1;135:207-14.
    PMID: 26453870 DOI: 10.1016/j.carbpol.2015.08.051
    Floating hydrogels were prepared from kappa carrageenan containing CaCO3 and NaHCO3 as pore forming agents. The effects of CaCO3 and NaHCO3 on hydrogel characterizations were investigated and compared. Amoxicillin trihydrate was used as a model drug. Characterizations of the hydrogels were carried out using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). As pore forming agents concentration increases, the porosity (%) and floating properties increased. NaHCO3 incorporated hydrogels showed higher porosity with shorter floating lag time (FLT) than CaCO3. Hydrogel which contained CaCO3 exhibited better gel stability over the control and NaHCO3 containing gel. Incorporation of CaCO3 into kappa carrageenan hydrogel showed smoother surface gels compared to those produced with NaHCO3. CaCO3 also showed higher drug entrapment efficiency and sustained drug release profile than NaHCO3. The results of these studies showed that, CaCO3 is an effective pore forming agents in κC hydrogels preparation as compare to NaHCO3. Thus, CaCO3 can be an excellent pore forming agent for an effective floating drug delivery system.
  18. Fulltext Ser-653-Asn substitution in the acetohydroxyacid synthase gene confers resistance in weedy rice to imidazolinone herbicides in Malaysia
    Ruzmi R, Ahmad-Hamdani MS, Mazlan N
    PLoS One, 2020;15(9):e0227397.
    PMID: 32925921 DOI: 10.1371/journal.pone.0227397
    The continuous and sole dependence on imidazolinone (IMI) herbicides for weedy rice control has led to the evolution of herbicide resistance in weedy rice populations across various countries growing IMI herbicide-resistant rice (IMI-rice), including Malaysia. A comprehensive study was conducted to elucidate occurrence, level, and mechanisms endowing resistance to IMI herbicides in putative resistant (R) weedy rice populations collected from three local Malaysian IMI-rice fields. Seed bioassay and whole-plant dose-response experiments were conducted using commercial IMI herbicides. Based on the resistance index (RI) quantification in both experiments, the cross-resistance pattern of R and susceptible (S) weedy rice populations and control rice varieties (IMI-rice variety MR220CL2 and non-IMI-rice variety MR219) to imazapic and imazapyr was determined. A molecular investigation was carried out by comparing the acetohydroxyacid synthase (AHAS) gene sequences of the R and S populations and the MR220CL2 and MR219 varieties. The AHAS gene sequences of R weedy rice were identical to those of MR220CL2, exhibiting a Ser-653-Asn substitution, which was absent in MR219 and S plants. In vitro assays were conducted using analytical grade IMI herbicides of imazapic (99.3%) and imazapyr (99.6%) at seven different concentrations. The results demonstrated that the AHAS enzyme extracted from the R populations and MR220CL2 was less sensitive to IMI herbicides than that from S and MR219, further supporting that IMI herbicide resistance was conferred by target-site mutation. In conclusion, IMI resistance in the selected populations of Malaysian weedy rice could be attributed to a Ser-653-Asn mutation that reduced the sensitivity of the target site to IMI herbicides. To our knowledge, this study is the first to show the resistance mechanism in weedy rice from Malaysian rice fields.
  19. Fulltext Correction: Ser-653-Asn substitution in the acetohydroxyacid synthase gene confers resistance in weedy rice to imidazolinone herbicides in Malaysia
    Ruzmi R, Ahmad-Hamdani MS, Mazlan N
    PLoS One, 2020;15(12):e0244686.
    PMID: 33351858 DOI: 10.1371/journal.pone.0244686
    [This corrects the article DOI: 10.1371/journal.pone.0227397.].
  20. Shifts in foraging behaviour of heterospecific flocking birds in a lowland Malaysian rainforest
    Mansor MS, Nor SM, Ramli R
    Behav Processes, 2020 Nov;180:104229.
    PMID: 32866554 DOI: 10.1016/j.beproc.2020.104229
    Mixed-species flocks (MSFs) serve important roles in bird communities, especially in tropical forests. Although structure of mixed-species bird flocks and its benefits has been intensively studied globally, the foraging plasticity of a species when joining MSFs has rarely been evaluated. The present study examines foraging strategies of the Rufous-crowned Babbler (Malacopteron magnum), Chestnut-winged Babbler (Cyanoderma erythropterum) and Black-naped Monarch (Hypothymis azurea) when participating in MSFs in the Krau Wildlife Reserve, central Peninsular Malaysia. These species exhibit active foraging shifts in utilisation of vertical strata, foraging substrate, attack manoeuvres and foliage density, when foraging in MSFs, compared to when foraging outside MSFs. While the Rufous-crowned Babbler and Chestnut-winged Babbler commonly used gleaning and stretching (to completely extend the legs or neck to reach the food items) manoeuvres when foraging outside MSFs, respectively, they adopted probing manoeuvre and frequently used higher strata upon joining MSFs. The Chestnut-winged Babbler tended to forage on the underside of leaves and the Black-naped Monarch frequently utilised branches when joining MSFs, while they exclusively used aerial leaf litter and live green leaves, respectively, when foraging with conspecifics. The monarch also adopted the hovering manoeuvre and frequently foraged within denser foliage cover when joining MSFs. This study demonstrated that flock members exhibits foraging plasticity either through an expansion or active shift in foraging niches when participating in MSFs, thus suggesting the occurrence of possible foraging improvement and/or reductions in predation risk.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links