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  1. Ahmad D
    Malays J Med Sci, 2019 Jan;26(1):1-4.
    PMID: 30914889 DOI: 10.21315/mjms2019.26.1.1
    There have been substantial improvements in the health indicators since Malaysia achieved independence. These were accomplished through strong primary healthcare services addressing maternal and paediatric health, as well as the successful control of communicable diseases. The rate of decline in the mortality statistics has been at a virtual standstill, or at best, almost plateaued since 2000. However, with the plethora of national health issues at both the policy and delivery levels, we cannot continue on with 'business as usual'. Therefore, we must strategise effective and practical approaches to a renewed and revamped national healthcare services for a modern 'New Malaysia' that are compatible with our quest toward the status of a 'truly developed' nation.
  2. Ibrahim, M. G., Ahmad, D., Shehu, A. A., Dauda, S.M.
    MyJurnal
    Sheanut (Butyrospernum paradoxum) is an oil rich tropical tree crop, which is indigenous to
    the West African savannah zone. In Nigeria, most of the sheanuts shelling are done manually
    by rural women and children, which is labour demanding and tedious. This research work
    was carried out to determine some physical and mechanical properties of sheanut in order
    to minimize economic losses associated with its processing. The mean values recorded
    for the physical properties at 25% moisture content (wb) are; major diameter (29.20 mm),
    intermediate diameter (21.90 mm), minor diameter (15.00 mm), geometric mean diameter
    (21.90 mm), arithmetic mean diameter (21.20 mm), angle of repose (30.280). The mean
    values for the mechanical properties are; linear limit force (0.80 kN), linear limit deformation
    (4.60 mm), bioyield point force (1.40 kN), bioyield point deformation (6.50 mm), rupture
    point force (2.10 kN) and rupture point deformation (9.60 mm). Based on the physical and
    mechanical properties, a sheanut shelling machine was developed that is capable of addressing
    the aforementioned problems. Putting into consideration better shelling and efficient separation
    of shea nuts so as to encourage more utilization and processing of shea nuts and its products.
    The machine was designed to be powered by 5 hp electric motor. It was tested to shell, separate
    and clean sheanuts. The result of the performance evaluation showed that the machine had
    shelling efficiency of 96%; cleaning efficiency of the machine was 69.56% while the recovery
    efficiency was 82.7%. The successful development of this machine will reduce drudgery and
    time taken associated with the traditional method of sheanut shelling and therefore will increase
    productivity and utilization.
  3. Ahmad, D., Jamarei, O., Sulaiman, S., Fashina, A.B., Akande, F.B.
    MyJurnal
    The motion resistances of 660 mm pneumatic and rigid bicycle wheels of the same rim diameter were measured experimentally using the developed tractor-towed single non-lug narrow wheel motion resistance test rig for traction studies. The motion resistances measured were taken to be the towing forces determined in real time using Mecmesin Basic Force Gauge (BFG 2500). The test variables included two test surfaces [tilled and wet (mud) surfaces], the dynamic load and the towing velocity. The tyre inflation pressure of 414 kPa was chosen to make the surface synonymous with that of the rigid wheel. Motion resistance ratios of the two wheels were determined empirically and through semi-empirical approach. The motion resistances of the rigid wheel were found to be greater than those of the pneumatic wheel for both surfaces. Consequently, the motion resistance ratios of the rigid wheel were greater than those obtained
    from the pneumatic wheel. Analysis of variance showed that there were significant differences between the means of the motion resistance measured on the test surfaces, as well as between the two wheels and their interactions with the test surfaces. The motion resistance ratio exhibited a linear relationship with the towing velocity, while the relationship with the dynamic load was quadratic. However, such a relationship is either direct or inverse with the respective variables. The motion resistance ratio models for the pneumatic and rigid wheels showed that on different test conditions of the dynamic loads and the towing velocities, the relationships between the motion resistance ratio and the dynamic load, and motion resistance with dynamic load were also different.
  4. Md. Akhir, H., Ahmad, D., Rukunudin, I. H., Shamsuddin, S., A. Yahya
    MyJurnal
    This paper describes a study on the design, fabrication and testing of a prototype digging device for sweet potato tubers in bris soil. The soil texture was sandy soil (fine sand 94.53%), with mean moisture content of 9.16% and mean bulk density of 1.44 g-cm-3. The soil was prepared in a soil bin. Three types of soil digging tools were designed and fabricated to determine the optimum draft force. These were Flat or plane, V-shaped and Hoe type blades. Plane and V-shaped blades were 30 cm long, and 13 cm wide, while the Hoe type had three rods, 25 mm in diameter, 30 cm long and 6.5 cm wide with sharp cutting edge. The digging tools were tested in a soil bin filled with bris soil to determine the optimum draft force and area of soil disturbance. The results were analysed using statistical analysis of variance (ANOVA). Comparison between all blade types and blade depths to measured draft force and the area of soil disturbed showed that the highest draft of 0.54 kN-m-2 was caused by a flat or plane blade at the optimum depth of 20 cm when the area of soil disturbed was 0.180 m2 . The V-shaped blade had the mean draft of 0.51 kN-m-2, with area of soil disturbance of 0.185 m2 . Thebest choice was V-shaped blade with a rake angle of 30o at 20 cm. depth. The selected blade was fixed onto the sweet potato harvester and tested on bris soil planted with sweet potato of Telong and VitAto varieties. The harvesting efficiency of the machine in bris soil was 93.64% and 90.49% for Telong (Plot A) and VitAto (Plot B) varieties, respectively. The average ground speed and turning time during operation for plots A and B was 0.56 km-hr-1 and 102.7 s and 0.99 km-hr-1 and 81.22 s, respectively. The harvesting efficiencies for both plots showed no significant difference. The total productive time (harvesting time) and unproductive time (turning time) in plot A, at a tractor speed of 0.56 km.hr-1, was 14.8 hours for harvesting a hectare of sweet potato ( 0.068 ha.hr-1). In plot B, the total time for harvesting a hectare of sweet potato was 8.35 hours (0.12 ha.hr-1) at a tractor speed of 0.99 km.hr-1. The average harvesting time for both plots was 11.47 hr.ha-1. The average field work rate was 0.087 ha.hr-1 or 34 man-hr.ha-1 compared to manual harvesting of 150 man-hrs.ha-1.
  5. Balami, A. A., Dauda S. M., Mohammed, I. S., Agunsoye, J. K., Abu, H., 1 Abubakar, Ahmad, D.
    MyJurnal
    The processing of cocoyam tubers for industrial or human use involves different operations
    of which peeling is the major problem. This study was aimed at designing, fabricating and
    carrying out performance evaluation of a cocoyam peeling machine, taking into consideration
    some physical and mechanical properties of the cocoyam tubers. The machine was evaluated
    based on the following parameters which includes; throughput capacity and peeling efficiency
    at the speeds of 400 rpm, 700 rpm and 933 rpm. Results revealed that, for all the speeds tested
    in the experiment, the corresponding peeling efficiencies of the machine were 50%, 64% and
    68% respectively while that of the throughput capacities were 63.20 kg/hr, 84.90 kg/hr and
    112.92 kg/hr respectively. It was observed that 933 rpm speed was the most suitable speed for
    the operation of this machine, as it had higher peeling efficiency of 68% with a throughput
    capacity of 112.92 kg/hr. These results showed appreciable improvement over manual method
    which is 20 – 35 kg/hr.
  6. Vijayaraghavan K, Ahmad D, Yazid AY
    J Hazard Mater, 2008 Jan 31;150(2):351-6.
    PMID: 17543454
    A new method of Standard Malaysian Rubber (SMR) process wastewater treatment was developed based on in situ hypochlorous acid generation. The hypochlorous acid was generated in an undivided electrolytic cell consisting of two sets of graphite as anode and stainless sheets as cathode. The generated hypochlorous acid served as an oxidizing agent to destroy the organic matter present in the SMR wastewater. For an influent COD concentration of 2960 mg/L at an initial pH 4.5+/-0.1, current density 74.5 mA/cm(2), sodium chloride content 3% and electrolysis period of 75 min, resulted in the following residual values pH 7.5, COD 87 mg/L, BOD(5) 60 mg/L, TOC 65 mg/L, total chlorine 146 mg/L, turbidity 7 NTU and temperature 48 degrees C, respectively. In the case of 2% sodium chloride as an electrolyte for the above said operating condition resulted in the following values namely: pH 7.2, COD 165 mg/L, BOD(5) 105 mg/L, TOC 120 mg/L, total chlorine 120 mg/L, turbidity 27 NTU and temperature 53 degrees C, respectively. The energy requirement were found to be 30 and 46 Wh/L, while treating 24 L of SMR wastewater at 2 and 3% sodium chloride concentration at a current density 74.5 mA/cm(2). The observed energy difference was due to the improved conductivity at high sodium chloride content.
  7. Vijayaraghavan K, Ahmad D, Ezani Bin Abdul Aziz M
    J Environ Manage, 2007 Jan;82(1):24-31.
    PMID: 16584834
    In this study treatment of palm oil mill effluent (POME) was investigated using aerobic oxidation based on an activated sludge process. The effects of sludge volume index, scum index and mixed liquor suspended solids during the acclimatizing phase and biomass build-up phase were investigated in order to ascertain the reactor stability. The efficiency of the activated sludge process was evaluated by treating anaerobically digested and diluted raw POME obtained from Golden Hope Plantations, Malaysia. The treatment of POME was carried out at a fixed biomass concentration of 3900+/-200mg/L, whereas the corresponding sludge volume index was found to be around 105+/-5mL/g. The initial studies on the efficiency of the activated sludge reactor were carried out using diluted raw POME for varying the hydraulic retention time, viz: 18, 24, 30 and 36h and influent COD concentration, viz: 1000, 2000, 3000, 4000 and 5000mg/L, respectively. The results showed that at the end of 36h of hydraulic retention time for the above said influent COD, the COD removal efficiencies were found to be 83%, 72%, 64%, 54% and 42% whereas at 24h hydraulic retention time they were 57%, 45%, 38%, 30% and 27%, respectively. The effectiveness of aerobic oxidation was also compared between anaerobically digested and diluted raw POME having corresponding CODs of 3908 and 3925mg/L, for varying hydraulic retention time, viz: 18, 24, 30, 36, 42, 48, 54 and 60h. The dissolved oxygen concentration and pH in the activated sludge reactor were found to be 1.8-2.2mg/L and 7-8.5, respectively. The scum index was found to rise from 0.5% to 1.9% during the acclimatizing phase and biomass build-up phase.
  8. Hussein AS, Ahmad R, Ibrahim N, Yusoff A, Ahmad D
    PMID: 27421713
    To assess the knowledge, attitudes and experience of a group of Malaysian dental health care providers regarding child physical abuse (CPA) cases in terms of frequency of occurrence, diagnosis, risk factors and reporting.
  9. Azuan NH, Khairunniza-Bejo S, Abdullah AF, Kassim MSM, Ahmad D
    Plant Dis, 2019 Dec;103(12):3218-3225.
    PMID: 31596688 DOI: 10.1094/PDIS-10-18-1721-RE
    Basal stem rot (BSR), caused by the Ganoderma fungus, is an infectious disease that affects oil palm (Elaeis guineensis) plantations. BSR leads to a significant economic loss and reductions in yields of up to Malaysian Ringgit (RM) 1.5 billion (US$400 million) yearly. By 2020, the disease may affect ∼1.7 million tonnes of fresh fruit bunches. The plants appear symptomless in the early stages of infection, although most plants die after they are infected. Thus, early, accurate, and nondestructive disease detection is crucial to control the impact of the disease on yields. Terrestrial laser scanning (TLS) is an active remote-sensing, noncontact, cost-effective, precise, and user-friendly method. Through high-resolution scanning of a tree's dimension and morphology, TLS offers an accurate indicator for health and development. This study proposes an efficient image processing technique using point clouds obtained from TLS ground input data. A total of 40 samples (10 samples for each severity level) of oil palm trees were collected from 9-year-old trees using a ground-based laser scanner. Each tree was scanned four times at a distance of 1.5 m. The recorded laser scans were synched and merged to create a cluster of point clouds. An overhead two-dimensional image of the oil palm tree canopy was used to analyze three canopy architectures in terms of the number of pixels inside the crown (crown pixel), the degree of angle between fronds (frond angle), and the number of fronds (frond number). The results show that the crown pixel, frond angle, and frond number are significantly related and that the BSR severity levels are highly correlated (R2 = 0.76, P < 0.0001; R2 = 0.96, P < 0.0001; and R2 = 0.97, P < 0.0001, respectively). Analysis of variance followed post hoc tests by Student-Newman-Keuls (Newman-Keuls) and Dunnett for frond number presented the best results and showed that all levels were significantly different at a 5% significance level. Therefore, the earliest stage that a Ganoderma infection could be detected was mildly infected (T1). For frond angle, all post hoc tests showed consistent results, and all levels were significantly separated except for T0 and T1. By using the crown pixel parameter, healthy trees (T0) were separated from unhealthy trees (moderate infection [T2] and severe infection [T3]), although there was still some overlap with T1. Thus, Ganoderma infection could be detected as early as the T2 level by using the crown pixel and the frond angle parameters. It is hard to differentiate between T0 and T1, because during mild infection, the symptoms are highly similar. Meanwhile, T2 and T3 were placed in the same group, because they showed the same trend. This study demonstrates that the TLS is useful for detecting low-level infection as early as T1 (mild severity). TLS proved beneficial in managing oil palm plantation disease.
  10. Ramanathan K, Jin LE, Keat TC, Omar-Ahmad DU
    Dent J Malaysia Singapore, 1970 May;10(1):15-34.
    PMID: 5271011
  11. Jamal F, George J, Aziz AA, Ahmad D
    Family Practitioner, 1986;9(1):38-39.
    Pharyngeal carriage of group A streptococcus was determined in 432 primary school children between the ages of 6 and 8 years. Beta-haemolytic streptococci were isolated from throat swab culture of 71 pupils, with a carrier rate of 16.4% (71/432) of which 9.4% (39/432) belonged to Lancefield's group A. Serogrouping of the isolates was determined by the coagglutination method and Lancefield's hot acid extraction method. 54.9% (39/71) of the total beta-hemolytic streptococci isolated belonged to group A , 25.3% (18/71) to group G, 15.4% (11/71) to group C and 1.4%(1/71) to group F. T typing pattern of group A streptococcus was determined by the standard agglutination method. Sensitivity to antibiotics was determined by the disc diffusion technique (comparative method). All group A streptococcal isolates were sensitive to penicillin and erythromycin, 6 strains (15.4%) were resistant to tetracycline and 1 strain (2.5%) was resistant to cephaloridine.
  12. Alkhayl FFA, Ismail AD, Celis-Morales C, Wilson J, Radjenovic A, Johnston L, et al.
    Sci Rep, 2022 Feb 15;12(1):2469.
    PMID: 35169204 DOI: 10.1038/s41598-022-06446-7
    The aims of the current study, therefore, were to compare (1) free-living MPS and (2) muscle and metabolic adaptations to resistance exercise in South Asian and white European adults. Eighteen South Asian and 16 White European men were enrolled in the study. Free-living muscle protein synthesis was measured at baseline. Muscle strength, body composition, resting metabolic rate, VO2max and metabolic responses (insulin sensitivity) to a mixed meal were measured at baseline and following 12 weeks of resistance exercise training. Free-living muscle protein synthesis was not different between South Asians (1.48 ± 0.09%/day) and White Europeans (1.59 ± 0.15%/day) (p = 0.522). In response to resistance exercise training there were no differences, between South Asians and White Europeans, muscle mass, lower body strength or insulin sensitivity. However, there were differences between the ethnicities in response to resistance exercise training in body fat, resting carbohydrate and fat metabolism, blood pressure, VO2max and upper body strength with responses less favourable in South Asians. In this exploratory study there were no differences in muscle protein synthesis or anabolic and metabolic responses to resistance exercise, yet there were less favourable responses in several outcomes. These findings require further investigation.
  13. Harun NH, Misron N, Sidek RM, Aris I, Ahmad D, Wakiwaka H, et al.
    Sensors (Basel), 2013;13(2):2254-66.
    PMID: 23435051 DOI: 10.3390/s130202254
    From the Malaysian harvester's perspective, the determination of the ripeness of the oil palm (FFB) is a critical factor to maximize palm oil production. A preliminary study of a novel oil palm fruit sensor to detect the maturity of oil palm fruit bunches is presented. To optimize the functionality of the sensor, the frequency characteristics of air coils of various diameters are investigated to determine their inductance and resonant characteristics. Sixteen samples from two categories, namely ripe oil palm fruitlets and unripe oil palm fruitlets, are tested from 100 Hz up to 100 MHz frequency. The results showed the inductance and resonant characteristics of the air coil sensors display significant changes among the samples of each category. The investigations on the frequency characteristics of the sensor air coils are studied to observe the effect of variations in the coil diameter. The effect of coil diameter yields a significant 0.02643 MHz difference between unripe samples to air and 0.01084 MHz for ripe samples to air. The designed sensor exhibits significant potential in determining the maturity of oil palm fruits.
  14. Husin NA, Khairunniza-Bejo S, Abdullah AF, Kassim MSM, Ahmad D, Azmi ANN
    Sci Rep, 2020 04 15;10(1):6464.
    PMID: 32296108 DOI: 10.1038/s41598-020-62275-6
    Ground-based LiDAR also known as Terrestrial Laser Scanning (TLS) technology is an active remote sensing imaging method said to be one of the latest advances and innovations for plant phenotyping. Basal Stem Rot (BSR) is the most destructive disease of oil palm in Malaysia that is caused by white-rot fungus Ganoderma boninense, the symptoms of which include flattening and hanging-down of the canopy, shorter leaves, wilting green fronds and smaller crown size. Therefore, until now there is no critical investigation on the characterisation of canopy architecture related to this disease using TLS method was carried out. This study proposed a novel technique of BSR classification at the oil palm canopy analysis using the point clouds data taken from the TLS. A total of 40 samples of oil palm trees at the age of nine-years-old were selected and 10 trees for each health level were randomly taken from the same plot. The trees were categorised into four health levels - T0, T1, T2 and T3, which represents the healthy, mildly infected, moderately infected and severely infected, respectively. The TLS scanner was mounted at a height of 1 m and each palm was scanned at four scan positions around the tree to get a full 3D image. Five parameters were analysed: S200 (canopy strata at 200 cm from the top), S850 (canopy strata at 850 cm from the top), crown pixel (number of pixels inside the crown), frond angle (degree of angle between fronds) and frond number. The results taken from statistical analysis revealed that frond number was the best single parameter to detect BSR disease as early as T1. In classification models, a linear model with a combination of parameters, ABD - A (frond number), B (frond angle) and D (S200), delivered the highest average accuracy for classification of healthy-unhealthy trees with an accuracy of 86.67 per cent. It also can classify the four severity levels of infection with an accuracy of 80 per cent. This model performed better when compared to the severity classification using frond number. The novelty of this research is therefore on the development of new approach to detect and classify BSR using point clouds data of TLS.
  15. Shah SA, Rosenberg M, Ahmad D, Ahmad S, Safian N, Shobugawa Y
    Health Res Policy Syst, 2022 Nov 29;20(Suppl 1):127.
    PMID: 36443790 DOI: 10.1186/s12961-022-00915-1
    BACKGROUND: Hypertension is a major cause of morbidity and mortality worldwide. Although multiple studies have assessed the prevalence of hypertension among older people, no study has examined the unmet need for hypertension care among older people in Malaysia. This study uses the hypertension care cascade to identify the prevalence of unmet needs for hypertension care and their determinants among the older population in Selangor.

    METHODS: This is a cross-sectional study involving a total of 1204 participants recruited from different areas in Selangor. A face-to-face interview was conducted using the Bahasa Malaysia version of the Japan Gerontological Evaluation Study questionnaire. The inclusion criteria were Malaysians aged ≥ 60 years who could converse in Bahasa Malaysia.

    RESULTS: Among the 637 participants with hypertension, 18% (117) had not been previously screened but were found to have BP ≥ 140/90 mmHg, 21% (136) were undiagnosed, 3% (17) were untreated, 42% (267) were treated with antihypertensive medication but still had high blood pressure, and 16% (100) had hypertension that was controlled with medication. The hypertension care cascade demonstrates that 18% (117) of those with hypertension had never been screened for hypertension; 26% (136/520) of those who were screened never received a diagnosis; 4% (17/384) of those who were diagnosed did not receive treatment; and 73% (267/367) of those who were treated did not reach the threshold for control. The prevalence of total unmet needs was 84% (537/637). Statistically significant determinants of having any unmet need for hypertension care were smoking status and medical history, with adjusted odds ratios and 95% confidence intervals (CIs) in the multivariate analysis of 0.5 (95% CI: 0.3-0.9) for being a smoker, 2.8 (95% CI: 1.1-6.9) for having a history of stroke and 1.6 (95% CI: 1.0-2.5) for having a history of diabetes mellitus.

    CONCLUSIONS: The prevalence of unmet need for hypertension care among the older population in Selangor is 84% (537/637), which is alarmingly high. This study highlights where and how much of the loss of care for hypertension happens in the care cascade and provides insight into the efforts required to improve effective service coverage to manage the increasing burden of hypertension associated with population ageing.

  16. Jane Ling MY, Abdul Halim AFN, Ahmad D, Ahmad N, Safian N, Mohammed Nawi A
    PMID: 36900893 DOI: 10.3390/ijerph20053883
    The use of e-cigarettes in adolescents remains a major public health concern. Like other tobacco products, e-cigarettes pose health risks to adolescents. Understanding the magnitude of this problem and identification of its associated factors will serve as a guide for development of preventive interventions. This systematic review aims to identify and discuss current epidemiological data on the prevalence and associated factors of e-cigarette use among adolescents in Southeast Asia. The reporting of this systematic review is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. We carried out a literature search through three databases (Scopus, PubMed, Web of Science) and targeted original English-language articles published between 2012 and 2021. A total of 10 studies were included in this review. The prevalence of current e-cigarette uses ranges from 3.3% to 11.8%. Several associated factors of e-cigarette use were identified, including sociodemographic factors, traumatic childhood experience, peer and parental influence, knowledge and perception, substance use, and accessibility of e-cigarettes. These factors should be addressed though multifaceted interventions which simultaneously target multiple factors. Laws, policies, programs, and interventions must be strengthened and tailored to the needs of adolescents at risk of using e-cigarettes.
  17. Abdul Halim AFN, Ahmad D, Miaw Yn JL, Masdor NA, Ramly N, Othman R, et al.
    Int J Environ Res Public Health, 2022 Oct 10;19(19).
    PMID: 36232271 DOI: 10.3390/ijerph191912971
    Mass drug administration (MDA) has been implemented as a tool to eliminate lymphatic filariasis. Acceptability among susceptible populations is crucial to achieving MDA effective coverage. This systematic review aims to present and systematically determine the factors associated with the acceptability of MDA. Articles related to factors associated with acceptability were collected electronically from three different databases (Scopus, Web of Science, and PubMed). Four pairs of independent reviewers screened the titles and abstracts of the collected data, stored in EndnoteX7, against the inclusion criteria. Afterwards, the included articles have been critically appraised to assess the quality of the studies using the Mixed Method Appraisal Tool (MMAT). Of the 68 articles identified, 11 were included in the final review. Knowledge, awareness, attitude and perceptions, communications, delivery and accessibility of MDA, gender, and age are the factors associated with MDA acceptability. Community acceptance remains a challenge in the implementation of MDA. To expand MDA coverage in all endemic countries, there is a strong need to address the factors influencing community acceptance of MDA.
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