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An Assessment of the Training of the Traditional Birth Attendant of Rural Malaysia

Paul Chen CY

Med J Malaysia, 1976 Dec;31(2):93-99.
PMID: 35008149

No abstract available.
Fulltext A quantitative study on the effects of an interactive multimodal application to promote students' learning motivation and comprehension in studying Tang poetry

Chen C, Jamiat N

Front Psychol, 2023;14:1189864.
PMID: 37359868 DOI: 10.3389/fpsyg.2023.1189864

Studying China's Tang poetry is a crucially integrated part of the language curriculum in primary schools because it is an important part of its cultural heritage and classical literature. However, due to the fact that Tang poetry is written in classical Chinese, which is quite different from modern Chinese Mandarin, and the complex categories of this poetry style, learning Tang poetry can be a challenging experience for many students. To address this problem, this study developed an interactive multimodal application based on the cognitive-affective theory of learning with media to learn Tang poetry in an interactive way. In order to assess the effectiveness of this method, a pretest-posttest control group experiment was conducted. The experiment included eighty third-grade students randomly and equally divided into experimental and control groups from an elementary school in Xinzheng, Henan Province, to test (1) whether the interactive multimodal application improves students' reading comprehension of Tang poetry and (2) whether the application enhances students' intrinsic and/or extrinsic motivation in learning Tang poetry. A multimodal interactive application was used by the experimental group to learn Tang poetry, while the control group used a traditional classroom method. According to the study's findings, it was found that students' intrinsic motivation and comprehension of Tang poetry improved through the use of the interactive multimodal application mode.
Prevalence of piriformis syndrome in chronic low back pain patients. A clinical diagnosis with modified FAIR test

Kean Chen C, Nizar AJ

Pain Pract, 2013 Apr;13(4):276-81.
PMID: 22863240 DOI: 10.1111/j.1533-2500.2012.00585.x

Piriformis syndrome is a collection of symptoms and signs of pain from piriformis muscle and is characterized by pain in buttock with variable involvement of sciatic nerve. This syndrome is often overlooked in clinical practice because its presentation has similarities with other spine pathologies. A major problem with the clinical diagnosis of piriformis syndrome is the lack of consistent objective findings and an absence of single test that is specific for piriformis syndrome. Therefore, a precise and reliable clinical method of diagnosing piriformis syndrome should be developed by clinicians.
Knowledge and perception of oral health promotion in schools among dental nurses in Sarawak, Malaysia

Chen CJ, Jallaludin RL

Asia Pac J Public Health, 2000;12(1):12-6.
PMID: 11200211

In recent years, the concept of a Health-Promoting School has received much interest. In Malaysia, dental nurses are ideally placed to play a lead role in promoting Oral Health within the school setting. This study aims to provide information on the knowledge, perception and perceived role of Oral Health Promotion in schools, among dental nurses. A postal questionnaire was used to measure dental nurses' knowledge, perception and perceived role of Oral Health Promotion. The majority (60%) of dental nurses had good knowledge of Oral Health Promotion. Generally, they perceived that they play an important role in promoting Oral Health in schools. However, a sizeable proportion (25%) did not think they had a role to play in working together with school authorities to provide children with healthy food choices in school canteens. The majority (60%) of dental nurses did not perceive Oral Health Promotion to be important as a whole. They had a good perception of the concepts: it supports behaviour change, it has appropriate goals, it integrates oral health and general health and relieves anxiety. However, they had a poorer perception of the concepts; diverse educational approaches, participation, focus on prevention, early intervention, "spread of effect" of dental health education and "make healthier choices the easier choices". Years of service was not significantly associated with knowledge and perception of Oral Health Promotion. Dental nurses should be reoriented towards a more holistic practice of Oral Health Promotion. Workshops that invite active participation from dental nurses should be conducted to equip them with the necessary knowledge and skills.
Fulltext Laboratory bioefficacy of CREEK 1.0G (temephos) against Aedes (Stegomyia) aegypti (Linnaeus) larvae

Chen CD, Lee HL

Trop Biomed, 2006 Dec;23(2):220-3.
PMID: 17322825 MyJurnal

The bioefficacy of a commercial formulation of temephos, Creek against Aedes aegypti larvae was studied in the laboratory. Earthen jars were filled with 10 L tap water each. One g of temephos (Creek) sand granule formulation was added into each earthen jar as recommended by the manufacturer. The final test concentration of Creek was 1 mg a.i./L. One earthen jar was filled with 10 L tap water and served as a test control (untreated). Thirty late 3(rd) or early 4(th) instar of lab-bred Ae. aegypti larvae were added into each earthen jar. Mortality of the larvae was recorded after 24 hours and percent mortality was calculated. Test was repeated every week. The results showed that complete larval mortality was achieved after 24 hours. The residual effect lasted 15 weeks (105 days), indicating that Creek is effective at the dosage recommended by the manufacturer which is 1 mg a.i./L.
Fulltext Toxicity of imidacloprid gel bait against laboratory strain of periplaneta americana (l.) (dictyoptera : blattidae) and blattella germanica (l.) (dictyoptera : blattellidae)

CoRe, H. W., Lee, H. L., M. Sofian-Azirun, Nura-Muna, A. H., Chen, C. D., O. Wan-Norafikah

Jurnal Sains Kesihatan Malaysia, 2017;15(2):37-42.
MyJurnal

The efficacy of a 2.15% imidacloprid gel bait against laboratory strain Periplaneta americana and Blattella germanica
was evaluated under laboratory conditions. The susceptibility trend of both species towards imidacloprid was: adult male
< adult female < nymphs. All stages of both species were dead within 10 days in primary poisoning testing. Periplaneta
americana adult male (LT50 = 0.47 h; LT95 = 5.24 h) died fastest, while nymphs of B. germanica took the longest time to
reach 95% mortality (LT95 = 43.84 h). In indirect exposure via secondary poisoning, only adult males of P. americana (LT50
= 100.63 h) and B. germanica (LT50 = 54.66 h) obtained 50% mortality before the testing ended. No complete mortalities
were achieved in any stages of both species within 10 days of secondary poisoning testing. Therefore, imidacloprid gel
bait used in this study was able to cause complete mortalities within less than 2 days of 10-day primary poisoning testing
but less effective in the 10-day secondary poisoning testing.
A Filippov model describing the effects of media coverage and quarantine on the spread of human influenza

Chen C, Chong NS, Smith R

Math Biosci, 2018 02;296:98-112.
PMID: 29273381 DOI: 10.1016/j.mbs.2017.12.002

Mass-media reports on an epidemic or pandemic have the potential to modify human behaviour and affect social attitudes. Here we construct a Filippov model to evaluate the effects of media coverage and quarantine on the transmission dynamics of influenza. We first choose a piecewise smooth incidence rate to represent media reports being triggered once the number of infected individuals exceeds a certain critical level [Formula: see text] . Further, if the number of infected cases increases and exceeds another larger threshold value [Formula: see text] ( [Formula: see text] ), we consider that the incidence rate tends to a saturation level due to the protection measures taken by individuals; meanwhile, we begin to quarantine susceptible individuals when the number of susceptible individuals is larger than a threshold value Sc. Then, for each susceptible threshold value Sc, the global properties of the Filippov model with regard to the existence and stability of all possible equilibria and sliding-mode dynamics are examined, as we vary the infected threshold values [Formula: see text] and [Formula: see text] . We show generically that the Filippov system stabilizes at either the endemic equilibrium of the subsystem or the pseudoequilibrium on the switching surface or the endemic equilibrium [Formula: see text] depending on the choice of the threshold values. The findings suggest that proper combinations of infected and susceptible threshold values can maintain the number of infected individuals either below a certain threshold level or at a previously given level.
Evaluation of insecticide resistance among Malaysian Aedes albopictus Skuse larvae based on revised diagnostic doses of larvicides

Wan-Norafikah O, Chen CD, Sofian-Azirun M

Trop Biomed, 2023 Sep 01;40(3):320-330.
PMID: 37897165 DOI: 10.47665/tb.40.3.008

The susceptibility levels of Malaysian Aedes albopictus larvae sampled from several agricultural, fogging-free residential and dengue prone residential areas against different larvicides were evaluated using revised diagnostic doses derived from the 2xLC99 values of the reference strain. Upon 24-hour recovery period of WHO larval bioassay, incipient resistance was observed among Ae. albopictus larvae from rubber estates against fenitrothion (96.67% mortality) and permethin (97.00% mortality) while Ae. albopictus larvae from rice cultivation areas were moderately resistant to fenthion (94.33% mortality). Aedes albopictus larvae from dengue prone residential areas developed moderate to high resistance against dichlorodiphenyltrichloroethane (DDT), fenitrothion, fenthion, propoxur and permethrin (79.67% - 97.33% mortality). Moderate to high resistance were also demonstrated among all populations of Ae. albopictus larvae against temephos and chlorpyrifos (63.00% - 97.67% mortality). Except for Ae. albopictus larvae from oil palm plantations, all Ae. albopictus larval populations were also highly resistant to bendiocarb (65.67% - 89.67% mortality). Cross resistance between larvicides from similar and different insecticide classes were also revealed in this study. The use of revised diagnostic doses established from the local reference strain could reduce the possibility of underestimation or overestimation of the insecticide susceptibility status of field strain populations.
Fulltext The study on the effects of gamified interactive e-books on students' learning achievements and motivation in a Chinese character learning flipped classroom

Chen C, Jamiat N, Mao Y

Front Psychol, 2023;14:1236297.
PMID: 37599782 DOI: 10.3389/fpsyg.2023.1236297

Existing empirical research has demonstrated the positive effects of flipping the classroom to improve student motivation and achievement by flipping in-class learning content to pre-class. However, the flipped classroom approach requires that students be engaged and motivated in the pre-class stage to ensure that the in-class learning activities run smoothly. Previous studies have highlighted the difficulties that students often encounter when trying to learn Chinese characters in Chinese language classes, especially those who are in the early stages of learning the language. Therefore, in this study, a gamified interactive e-book was developed and used in a flipped classroom for Chinese character learning. To evaluate the effectiveness of this approach, a pre-test and post-test control group experimental design was used. The participants were 90 s-grade students from a public primary school in Zhengzhou, China, who were randomly assigned to two experimental groups and one control group: the students who used a gamified interactive e-book in a Chinese character learning flipped classroom (GIEFC group), the students who used a traditional flipped classroom (TFC group), and the students who used a traditional teaching classroom (TTC group). The experimental results indicated that students in the GIEFC group scored higher than those in the TFC and TTC groups in terms of learning achievements and motivation. In addition, the experimental results also demonstrated the positive effects of gamified interactive e-books in flipped classroom learning. Future research could explore a variety of different types of game elements as well as the extension of research to other subjects.
Fulltext Longitudinal Zeolite-Iron Oxide Nanocomposite Deposited Capacitance Biosensor for Interleukin-3 in Sepsis Detection

Chen C, Gopinath SCB, Anbu P

Nanoscale Res Lett, 2021 Apr 26;16(1):68.
PMID: 33900481 DOI: 10.1186/s11671-021-03527-w

Sepsis is an extreme condition involving a physical response to severe microbial infection and causes fatal and life-threatening issues. Sepsis generates during the chemicals release with the immune system into the bloodstream for fighting against an infection, which causes the inflammation and leads to the medical emergency. A complexed longitudinal zeolite and iron oxide nanocomposite was extracted from coal mine fly ash and utilized to improve the surface characteristics of the capacitance biosensor to identify sepsis attacks. Anti-interleukin-3 (anti-IL-3) antibody was attached to the zeolite- and iron oxide-complexed capacitance electrode surface through an amine linker to interact with the sepsis biomarker IL-3. The morphological and chemical components of the nanocomplex were investigated by FESEM, FETEM, and EDX analyses. At approximately 30 nm, the longitudinal zeolite and iron oxide nanocomposite aided in attaining the limit of IL-3 detection of 3 pg/mL on the linear curve, with a regression coefficient (R2) of 0.9673 [y = 1.638x - 1.1847]. A lower detection limit was achieved in the dose-dependent range (3-100 pg/mL) due to the higher amount of antibody immobilization on the sensing surface due to the nanomaterials and the improved surface current. Furthermore, control experiments with relevant biomolecules did not show capacitance changes, and spiked IL-3 in human serum increased capacitance, indicating the specific and selective detection of IL-3. This study identifies and quantifies IL-3 via potentially useful methods and helps in diagnosing sepsis attack.
Comparative evaluation of the effectiveness of desensitizing agents in dentine tubule occlusion using scanning electron microscopy

Chen CL, Parolia A, Pau A, Celerino de Moraes Porto IC

Aust Dent J, 2015 Mar;60(1):65-72.
PMID: 25721280 DOI: 10.1111/adj.12275

Dentine hypersensitivity (DH) occurs on exposed dentine and is dependent on the patency of dentinal tubules. This study compared the effectiveness of red propolis extract (RPE), calcium sodium phosphosilicate (Novamin) and arginine-calcium carbonate (ACC) in occluding dentine tubules.
The lead content of currently available new residential paint in several Asian countries

Clark CS, Rampal KG, Thuppil V, Chen CK, Clark R, Roda S

Environ Res, 2006 Sep;102(1):9-12.
PMID: 16782088

Worldwide prohibitions on lead gasoline additives were a major international public health accomplishment, the results of which are still being documented in parts of the world. Although the need to remove lead from paints has been recognized for over a century, evidence reported in this article indicates that lead-based paints for household use, some containing more than 10% lead, are readily available for purchase in some of the largest countries in the world. Sixty-six percent of new paint samples from China, India, and Malaysia were found to contain 5000 ppm (0.5%) or more of lead, the US definition of lead-based paint in existing housing, and 78% contained 600 ppm (0.06%) or more, the limit for new paints. In contrast, the comparable levels in a nearby developed country, Singapore, were 0% and 9%. In examining lead levels in paints of the same brands purchased in different countries, it was found that some brands had lead-based paints in one of the countries and paints meeting US limits in another; another had lead-free paint available in all countries where samples were obtained. Lead-based paints have already poisoned millions of children and likely will cause similar damage in the future as paint use increases as countries in Asia and elsewhere continue their rapid development. The ready availability of lead-based paints documented in this article provides stark evidence of the urgent need for efforts to accomplish an effective worldwide ban on the use of lead in paint.
Fulltext The first report of terbinafine resistance Microsporum canis from a cat

Hsiao YH, Chen C, Han HS, Kano R

J Vet Med Sci, 2018 Jun 06;80(6):898-900.
PMID: 29657238 DOI: 10.1292/jvms.17-0680

A 2-year-old, exotic shorthair cat presented with baldness and mild scaling on trunk that was confirmed as Microsporum canis (M. canis) infection by the following methods. Wood's lamp and trichogram were used to demonstrate fungal elements suggestive of dermatophytosis consistent with M. canis. Dermatophyte test medium (DTM) and polymerase chain reaction (PCR) were used for identification. E-test and broth microdilution test were then utilized to estimate antifungal minimal inhibitory concentrations (MICs) towards ITZ and TRF respectively. The strain was isolated from the patient and revealed TRF MIC >32 µg/ml and ITZ MIC 0.023 µg/ml. Patient was cured of dermatophytosis with systemic ITZ.
Comparison of two in vitro antifungal sensitivity tests and monitoring during therapy of Sporothrix schenckii sensu stricto in Malaysian cats

Han HS, Kano R, Chen C, Noli C

Vet Dermatol, 2017 Feb;28(1):156-e32.
PMID: 28133872 DOI: 10.1111/vde.12417

BACKGROUND: Feline sporotrichosis is common in Malaysia. Thermosensitivity and effects of azole treatment on fungal susceptibility are unknown.
OBJECTIVES: To evaluate thermotolerance and antifungal susceptibility of feline Malaysian Sporothrix isolates, compare microdilution (MD) and E-test results, and investigate changes in susceptibility during azole therapy.
METHODS: Sporothrix schenckii sensu stricto was isolated from 44 cats. Thermotolerance was determined via culture at 37°C for 7 days. Susceptibility to itraconazole (ITZ), ketoconazole (KTZ) and terbinafine (TRB) was assessed in 40 isolates by MD; to amphotericin B (AMB), KTZ, ITZ, fluconazole (FLC) and posaconazole (POS) by E-test. Results were statistically compared by Pearson's Product Moment. In eight ketoconazole treated cats, susceptibility testing to itraconazole and ketoconazole was repeated every two months for six months.
RESULTS: Thermotolerance was observed in 36 of 44 (82%) isolates. Assuming that isolates growing at antifungal concentrations ≥4 mg/mL were resistant, all were resistant on E-test to FLC and AMB, 11 (28%) to POS, 6 (15%) to ITZ and 1 (3%) to KTZ. On MD, 27 of 40 (68%) were resistant to TRB, 2 (5%) to ITZ and 3 (8%) to KTZ. There was no correlation between E-test and MD results (KTZ r = 0.10, P = 0.54, and ITZ r = 0.11, P = 0.48). MD values for ITZ and KTZ did not exceed 4 mg/L during KTZ therapy.
CONCLUSION: The majority of feline isolates in Malaysia are thermosensitive. Lack of correlation between E-test and MD suggests that the E-test is unreliable to test antifungal susceptibility for Sporothrix spp. compared to MD. KTZ was the antifungal drug with the lowest MIC. Prolonged KTZ administration may not induce changes in antifungal susceptibility.
First Report of Stem-End Rot of Mango Caused by Phomopsis mangiferae in Taiwan

Ko Y, Liu CW, Chen CY, Maruthasalam S, Lin CH

Plant Dis, 2009 Jul;93(7):764.
PMID: 30764368 DOI: 10.1094/PDIS-93-7-0764A

Mango (Mangifera indica L.) is grown on approximately 20,000 ha in Taiwan. It is an economically important crop and the income of many fruit farmers comes primarily from mango production. During 2006 and 2007, a stem-end rot disease was observed 1 week after harvest on 28 to 36% of stored mangoes picked from six orchards in the Pingtung, Tainan, and Kaoshiung regions. Two popular mango cultivars, Keitt and Irwin, showed greater susceptibility to this disease, while 'Haden' was found to be moderately susceptible. In storage, symptoms initially appeared as light-to-dark brown lesions surrounding peduncles. Rot symptoms advanced slowly but eventually penetrated the mesocarp, which consequently reduced the commercial value of fruits. The fungus formed abundant pycnidia (0.1 to 0.6 mm in diameter) on infected fruits in advanced stages of symptom development. Pieces of symptomatic fruits plated on acidified potato dextrose agar (PDA) and incubated at 25 ± 1°C consistently yielded the same fungus. A single conidial isolate was cultured. Pycnidia developed on PDA after continuous exposure to light for 9 to 14 days. On the basis of morphological characteristics, the fungus was identified as Phomopsis mangiferae L. (2,3). Pycnidia released two types of conidia: α-conidia (5 to 10 × 2.3 to 4.0 μm) were hyaline and oval to fusoid; and β-conidia (15.0 to 37.5 × 1.3 to 2.5 μm) were hyaline and filiform with characteristic curves. Conidiophores were hyaline, filiform, simple or branched, septate, and 15 to 75 μm long. Cultures incubated under continuous fluorescent light (185 ± 35 μE·m-2·s-1) at 25°C for 3 days were used as inoculum for pathogenicity tests. Five fruits from 'Keitt' were wounded with a sterilized scalpel and each wound (2 × 2 × 2 mm) was inoculated with either a 5-mm mycelium agar plug or a 0.5-ml spore suspension (105 conidia per ml) of the fungus. Five wounded fruits inoculated with 5-mm PDA plugs or sterile water alone served as controls. Inoculated areas were covered with moist, sterile cotton. Fruits were enclosed in plastic bags and incubated at 24°C for 3 days. The test was performed three times. The same symptoms were observed on all inoculated fruits, whereas no decay was observed on control fruits. Reisolations from the inoculated fruits consistently yielded P. mangiferae, thus fulfilling Koch's postulates. This disease has previously been reported in Australia, Brazil, China, Cuba, India, Malaysia, and the United States (1). To our knowledge, this is the first report of P. mangiferae causing stem-end rot disease on mangoes in Taiwan. Our report necessitates taking preventive strategies in the field, prior to or after harvest, to contain postharvest losses in mangoes. References: (1) G. I. Johnson. Page 39 in: Compendium of Tropical Fruit Diseases. R. C. Ploetz et al., eds. The American Phytopathological Society. St. Paul, MN, 1994. (2) R. C. Ploetz, ed. Page 354 in: Diseases of Tropical Fruit Crops. CABI Publishing. Wallingford, UK, 2003. (3) E. Punithalingam. No. 1168 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK, 1993.
Fulltext Preliminary study on the effectiveness of mosquito repelling lamp, E Da

Chen CD, Azahari AH, Saadiyah I, Lee HL

Trop Biomed, 2007 Dec;24(2):89-91.
PMID: 18209714 MyJurnal

Photon (light) technology has already been widely used in make-up, medical treatment etc, but repelling mosquitoes by photon technology is an innovation. The objective of this study was to determine the efficacy of a mosquito repelling lamp, E Da under indoor conditions. E Da lamp is a lamp coated with yellow luminous pigment on the inner part of the glass bulb of the lamp which is used to screen out the UV radiation, and when it is turned on, the yellow illuminating wavelength will drive the mosquitoes away. The tests were conducted inside 2 cabins measuring 8' X 8' X 20'. The mosquito population was estimated by using the Bare Leg Catch (BLC) techniques. For treated test, E Da lamp was placed indoor 2 - 3 meters away from a human bait. Another cabin without the lamp was used as untreated control. BLC was conducted in both sites simultaneously. The mosquitoes collected in this study were solely those of Culex quinquefasciatus and Aedes albopictus. There was an 91.34% reduction of Cx. quinquefasciatus population in the treated test compared with the untreated cabin during the 4 hours catches (p < 0.05). E Da mosquito repelling lamp used in this study exerted repellency effect against the mosquitoes especially Cx. quinquefasciatus.
Fulltext Field evaluation of the bioefficacy of diflubenzuron (Dimilin) against container-breeding Aedes sp. mosquitoes

Chen CD, Seleena B, Chiang YF, Lee HL

Trop Biomed, 2008 Apr;25(1):80-6.
PMID: 18600208

The inhibitory activity of diflubenzuron, a chitin synthesis inhibitor, on the ecdysis of Aedes sp. larvae was evaluated in earthen jars and automobile tires. Two formulations of diflubenzuron were used in this study: Dimilin(R) WP (wettable powder), 25% and Dimilin GR (granular), 2%. The equivalent rate of 25 g/ha, 50 g/ha and 100 g/ha active ingredients for both WP and GR formulations were used in this study. Generally, at the higher dosage of 100 g/ha, both formulations were more effective against Aedes mosquitoes. On the whole, the WP formulation appeared to perform better than the GR formulation in terms of residual activity.
Fulltext Susceptibility of Aedes aegypti and Aedes albopictus to temephos in four study sites in Kuala Lumpur City Center and Selangor State, Malaysia

Chen CD, Nazni WA, Lee HL, Sofian-Azirun M

Trop Biomed, 2005 Dec;22(2):207-16.
PMID: 16883289 MyJurnal

Larvae obtained from Taman Samudera (Gombak, Selangor), Kampung Banjar (Gombak, Selangor), Taman Lembah Maju (Cheras, Kuala Lumpur) and Kampung Baru (City centre, Kuala Lumpur) were bioassayed with diagnostic dosage (0.012 mg/L) and operational dosage (1 mg/L) of temephos. All strains of Aedes aegypti and Aedes albopictus showed percentage mortality in the range of 16.00 to 59.05 and 6.4 to 59.50 respectively, after 24 hours. LT50 values for the 6 strains of Ae. aegypti and Ae. albopictus were between 41.25 to 54.42 minutes and 52.67 to 141.76 minutes respectively, and the resistance ratio for both Aedes species were in the range of 0.68 to 1.82 when tested with operational dosage, 1 mg/L temephos. These results indicate that Aedes mosquitoes have developed some degree of resistance. However, complete mortality for all strains were achieved after 24 hours when tested against 1 mg/L temephos.
Fulltext Weekly variation on susceptibility status of Aedes mosquitoes against temephos in Selangor, Malaysia

Chen CD, Nazni WA, Lee HL, Sofian-Azirun M

Trop Biomed, 2005 Dec;22(2):195-206.
PMID: 16883288 MyJurnal

Larvae of Aedes aegypti and Aedes albopictus obtained from 6 consecutive ovitrap surveillance (OS) in Taman Samudera and Kg. Banjar were evaluated for their susceptibility to temephos. Larval bioassays were carried out in accordance with WHO standard methods, with diagnostic dosage (0.012 mg/L) and operational dosage (1 mg/L) of temephos respectively. Aedes aegypti and Ae. albopictus obtained from six OS in Taman Samudera showed resistance to diagnostic dosage of temephos with percentage mortality between 5.3 to 72.0 and 9.3 to 56.0, respectively, while Ae. aegypti and Ae. albopictus obtained from Kg. Banjar showed resistance to temephos with percentage mortality between 16.0 to 72.0 and 0 to 50.6, respectively. Only two strains of Ae. aegypti from Kg. Banjar were susceptible to temephos with 93.3% (OS 2) and 100% (OS 3) mortality. The 50% mortality at lethal time (LT50) for all strains of Ae. aegypti and Ae. albopictus tested against operational dosage of temephos showed range between 36.07 to 75.69 minutes and 58.65 to 112.50 minutes, respectively, and complete mortality was achieved after 24 hours. Our results indicated that there is weekly variations of the resistance status for Ae. aegypti and Ae. albopictus. Aedes susceptibility to temephos is changing from time to time in these two study sites. It is essential to continue monitoring the resistance of this vector to insecticides in order to ensure the efficiency of program aimed at vector control and protection of human health.
First Report of Gray Leaf Spot of Mango (Mangifera indica) Caused by Pestalotiopsis mangiferae in Taiwan

Ko Y, Yao KS, Chen CY, Lin CH

Plant Dis, 2007 Dec;91(12):1684.
PMID: 30780618 DOI: 10.1094/PDIS-91-12-1684B

Mango (Mangifera indica L.; family Anacardiaceae) is one of the world's most important fruit crops and is widely grown in tropical and subtropical regions. Since 2001, a leaf spot disease was found in mango orchards of Taiwan. Now, the disease was observed throughout (approximately 21,000 ha) Taiwan in moderate to severe form, thus affecting the general health of mango trees and orchards. Initial symptoms were small, yellow-to-brown spots on leaves. Later, the irregularly shaped spots, ranging from a few millimeters to a few centimeters in diameter, turned white to gray and coalesced to form larger gray patches. Lesions had slightly raised dark margins. On mature lesions, numerous black acervuli, measuring 290 to 328 μm in diameter, developed on the gray necrotic areas. Single conidial isolates of the fungus were identified morphologically as Pestalotiopsis mangiferae (Henn.) Steyaert (2,3) and were consistently isolated from the diseased mango leaves on acidified (0.06% lactic acid) potato dextrose agar (PDA) medium incubated at 25 ± 1°C. Initially, the fungus grew (3 mm per day) on PDA as a white, chalky colony that subsequently turned gray after 2 weeks. Acervuli developed in culture after continuous exposure to light for 9 to 12 days at 20 to 30°C. Abundant conidia oozed from the acervulus as a creamy mass. The conidia (17.6 to 25.4 μm long and 4.8 to 7.1 μm wide) were fusiform and usually straight to slightly curved with four septa. Three median cells were olivaceous and larger than the hyaline apical and basal cells. The apical cells bore three (rarely four) cylindrical appendages. Pathogenicity tests were conducted with either 3-day-old mycelial discs or conidial suspension (105 conidia per ml) obtained from 8- to 10-day-old cultures. Four leaves on each of 10 trees were inoculated. Before inoculation, the leaves were washed with a mild detergent, rinsed with tap water, and then surface sterilized with 70% ethanol. Leaves were wounded with a needle and exposed to either a 5-mm mycelial disc or 0.2 ml of the spore suspension. The inoculated areas were wrapped with cotton pads saturated with sterile water and the leaves were covered with polyethylene bags for 3 days to maintain high relative humidity. Wounded leaves inoculated with PDA discs alone served as controls. The symptoms described above were observed on all inoculated leaves, whereas uninoculated leaves remained completely free from symptoms. Reisolation from the inoculated leaves consistently yielded P. mangiferae, thus fulfilling Koch's postulates. Gray leaf spot is a common disease of mangos in the tropics and is widely distributed in Africa and Asia (1-3); however, to our knowledge, this is the first report of gray leaf spot disease affecting mango in Taiwan. References: (1) T. K. Lim and K. C. Khoo. Diseases and Disorders of Mango in Malaysia. Tropical Press. Malaysia, 1985. (2) J. E. M. Mordue. No. 676 in: CMI Descriptions of Pathogenic Fungi and Bacteria. Surrey, England, 1980. (3) R. C. Ploetz et al. Compendium of Tropical Fruit Diseases. The American Phytopathological Society. St. Paul, MN, 1994.

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