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Showing papers by "University of Malaya published in 1998"


Journal ArticleDOI
TL;DR: An etiologic link between EV-71 and brainstem encephalomyelitis is postulated as the cause of pulmonary edema and death in children with sudden cardiopulmonary collapse in 1997.

322 citations


Journal ArticleDOI
01 Nov 1998
TL;DR: In this paper, an effective method for online system status monitoring and thus voltage collapse prediction is described, where the basic methodology implied in this technique is the investigation of each line of the system through calculating line stability indices.
Abstract: Investigation and online monitoring of power system stability have become vital factors to electric utility suppliers. At present power system utilities operate very close to the limit of system stability owing to an increasing number of new economic and environmental restrictions. Researchers have been trying to find out the most effective way for online system status monitoring, so that necessary precautions can be taken prior to voltage collapse. Several methods have been proposed for analysing voltage collapse phenomena. An effective method for online system status monitoring and thus voltage collapse prediction is described. The basic methodology implied in this technique is the investigation of each line of the system through calculating line stability indices. The proposed method was tested on the IEEE 24-bus reliability test system and has been found to be accurate and precise in voltage collapse prediction. A comparative study with other methods has also been carried out indicating that the proposed method has some advantages over the others.

278 citations


Journal ArticleDOI
Ming-Liang Tong1, Bao-Hui Ye1, Jiwen Cai1, Xiao-Ming Chen1, Seik Weng Ng1 
TL;DR: The results suggest that the guest 2, 4'-bpy molecules and protonated [4,4'-H(2)bpy](2+) cations present in the reaction systems serve as structure-directing templates in the formation of the crystal structures and exclude self-inclusion of the networks having larger square cavities.
Abstract: In the presence of guest 2,4'-bpy molecules or under acidic conditions, three compounds, [Cd(4,4'-bpy)(2)(H(2)O)(2)](ClO(4))(2).(2,4'-bpy)(2).H(2)O (1), [Zn(4,4'-bpy)(2)(H(2)O)(2)](ClO(4))(2).(2,4'-bpy)(2).H(2)O (2), and [Cu(4,4'-bpy)(2)(H(2)O)(2)](ClO(4))(4).(4,4'-H(2)bpy) (3), were obtained from the reactions of the metal salts and 4,4'-bpy in an EtOH-H(2)O mixture. 1 has a 2-D square-grid network structure, crystallizing in the monoclinic space group P2/n, with a = 13.231(3) A, b = 11.669(2) A, c = 15.019(3) A, beta = 112.82(3) degrees, Z = 2; 2 is isomorphous with 1, crystallizing in the monoclinic space group P2/n, with a = 13.150(3) A, b = 11.368(2) A, c = 14.745(3) A, beta = 110.60(3) degrees, Z = 2. The square grids superpose on each other into a channel structure, in which each layer consists of two pairs of shared edges, perfectly square-planar with an M(II) ion and a 4,4'-bpy at each corner and side, respectively. The square cavity has dimensions of 11.669(2) x 11.788(2) and 11.368(2) x 11.488(2) A for 1 and 2, respectively. Every two guest 2,4'-bpy molecules are clathrated in each hydrophobic host cavity and are further stabilized by pi-pi stacking and hydrogen bonding interactions. The NMR spectra clearly confirm that both 1 and 2 contain 4,4'-bpy and 2,4'-bpy molecules in a 1:1 ratio, which have stacking interaction with each other in the solution. 3 crystallizes in the orthorhombic space group Ibam, with a = 11.1283(5) A, b = 15.5927(8) A, c = 22.3178(11) A, Z = 4. 3 is made up of two-dimensional square [Cu(4)(4,4'-bpy)(4)] grids, where the square cavity has dimensions of 11.13 x 11.16 A. Each [4,4'-H(2)bpy](2+) cation is clathrated in a square cavity and stacks with one pair of opposite edges of the host square cavity in an offset fashion with the face-to-face distance of ca. 3.95 A. Within each cavity, the [4,4'-H(2)bpy](2+) cation forms twin three-center hydrogen bonds with two pairs of ClO(4)(-) anions. The results suggest that the guest 2,4'-bpy molecules and protonated [4,4'-H(2)bpy](2+) cations present in the reaction systems serve as structure-directing templates in the formation of the crystal structures and exclude self-inclusion of the networks having larger square cavities.

257 citations


Journal ArticleDOI
TL;DR: Observations suggest that overexpression of c-erbB3 protein could play an important role in tumour progression from non-invasive to invasive and, also, that it may have the potential to be used as a marker for poor prognosis of breast cancer.
Abstract: Expression of c-erbB3 protein was investigated in 104 primary breast carcinomas comprising nine comedo ductal carcinoma in situ (DCIS), 91 invasive ductal carcinomas and four invasive lobular carcinomas using two monoclonal antibodies, RTJ1 and RTJ2. Of the 91 invasive ductal carcinomas, seven contained the comedo DCIS component adjacent to the invasive component. An immunohistochemical technique was used to evaluate the association between expression of c-erbB3 and clinical parameters and tumour markers such as epidermal growth factor receptor (EGFR), c-erbB2, cathepsin-D and p53 in archival formalin-fixed paraffin-embedded tumour tissues. Our results indicated that RTJ1 and RTJ2 gave identical staining patterns and concordant results. It was found that the overexpression of c-erbB3 protein was observed in 67% (6/9) of comedo DCIS, 52% (44/84) of invasive ductal carcinomas, 71% (5/7) of carcinomas containing both the in situ and invasive lesions and 25% (1/4) of invasive lobular carcinomas. A significant relationship (P < 0.05) was observed between strong immunoreactivity of c-erbB3 protein and histological grade, EGFR and cathepsin-D, but not with expression of c-erbB2, p53, oestrogen receptor status, lymph node metastases or age of patient. However, we noted that a high percentage of oestrogen receptor-negative tumours (59%), lymph node-positive tumours (63%) and c-erbB2 (63%) were strongly positive for c-erbB3 protein. We have also documented that a high percentage of EGFR (67%), c-erbB2 (67%), p53 (75%) and cathepsin-D-positive DCIS (60%) were strongly positive for c-erbB3. These observations suggest that overexpression of c-erbB3 protein could play an important role in tumour progression from non-invasive to invasive and, also, that it may have the potential to be used as a marker for poor prognosis of breast cancer.

186 citations


Journal ArticleDOI
TL;DR: In this paper, the self-assembly of AgX (X = NO3-, ClO4-) with 2,4-bipyridine (2,4‘-bpy) was studied.
Abstract: Two compounds, [Ag(2,4‘-bpy)]NO3 (1) and [Ag(2,4‘-bpy)]ClO4 (2), were obtained from self-assembly of AgX (X = NO3-, ClO4-) with 2,4‘-bipyridine (2,4‘-bpy). 1 crystallizes in the orthorhombic space group Pbca, with a = 11.2884(7) A, b = 11.3981(10) A, c = 16.5299(13) A, and Z = 8, while 2 crystallizes in the monoclinic space group P21/c, with a = 10.6361(4) A, b = 9.9896(4) A, c = 11.2661(6) A, β = 98.527(4)°, and Z = 4. Both complexes consist of helical [Ag(2,4‘-bpy)]∞ chains that are surrounded by nitrate or perchlorate counterions. Adjacent helical chains are racemic. The AgI atom is linked to two nitrogen atoms of the 2-pyridyl and 4‘-pyridyl groups from two different 2,4‘-bpy ligands as well as to the oxygen atom of the counterion. In 1, another oxygen atom of the counterion is weakly coordinated to the AgI atom of an adjacent chain, thus bridging the helical chains into a wavy 2-D network structure, whereas in 2, adjacent helical chains are linked by the weak ligand-unsupported metal−metal interactio...

183 citations


Journal ArticleDOI
TL;DR: Out-of-hospital immobilization has little or no effect on neurologic outcome in patients with blunt spinal injuries, and the analysis was limited to patients with cervical injuries.
Abstract: Objective: To examine the effect of emergency immobilization on neurologic outcome of patients who have blunt traumatic spinal injuries. Methods: A 5-year retrospective chart review was carried out at 2 university hospitals. All patients with acute blunt traumatic spinal or spinal cord injuries transported directly from the injury site to the hospital were entered. None of the 120 patients seen at the University of Malaya had spinal immobilization during transport, whereas all 334 patients seen at the University of New Mexico did. The 2 hospitals were comparable in physician training and clinical resources. Neurologic injuries were assigned to 2 categories, disabling or not disabling, by 2 physicians acting independently and blinded to the hospital of origin. Data were analyzed using multivariate logistic regression, with hospital location, patient age, gender, anatomic level of injury, and injury mechanism serving as explanatory variables. Results: There was less neurologic disability in the unimmobilized Malaysian patients (OR 2.03; 95% CI 1.03–3.99; p = 0.04). This corresponds to a <2% chance that immobilization has any beneficial effect. Results were similar when the analysis was limited to patients with cervical injuries (OR 1.52; 95% CI 0.64–3.62; p = 0.34). Conclusion: Out-of-hospital immobilization has little or no effect on neurologic outcome in patients with blunt spinal injuries.

182 citations


Journal ArticleDOI
TL;DR: No mutation was found in any of the acromegaly and small FIHP families, suggesting that genetic defects other than the MEN1 gene might be involved and that additional such families need to be analyzed.
Abstract: Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disease characterized by neoplasia of the parathyroid glands, the endocrine pancreas, and the anterior pituitary gland. In addition, families with isolated endocrine neoplasia, notably familial isolated hyperparathyroidism (FIHP) and familial acromegaly, have also been reported. However, whether these families constitute MEN 1 variants or separate entities remains speculative as the genetic bases for these diseases are unclear. The gene for MEN 1 has recently been cloned and characterized. Using single strand conformation analysis (SSCA) and sequencing, we performed mutation analysis in: a) a total of 55 MEN 1 families from 7 countries, b) 13 isolated MEN 1 cases without family history of the disease, c) 8 acromegaly families, and d) 4 FIHP families. Mutations were identified in 27 MEN 1 families and 9 isolated cases. The 22 different mutations spread across most of the 9 translated exons and included frameshift (11), nonsense (6), splice (2), missense mutations (2), and in-frame deletions (1). Among the 19 Finnish MEN 1 probands, a 1466del12 mutation was identified in 6 families with identical 11q13 haplotypes and in 2 isolated cases indicating a common founder. One frameshift mutation caused by 359del4 (GTCT) was found in 1 isolated case and 4 kindreds of different origin and haplotypes; this mutation therefore represents a common "warm" spot in the MEN1 gene. By analyzing the DNA of the parents of an isolated case one mutation was confirmed to be de novo. No mutation was found in any of the acromegaly and small FIHP families, suggesting that genetic defects other than the MEN1 gene might be involved and that additional such families need to be analyzed.

180 citations


Journal ArticleDOI
01 Sep 1998
TL;DR: In this article, an effective method for real-time monitoring of power system status and voltage collapse prediction is described, which investigates each line of the system through calculating an indicator that varies from 0 (no load condition) to 1 (maximum permissible loading condition).
Abstract: The tendency towards maximising economic benefits has led power systems utilities to run close to the limits of stable operation. This has necessitated the study of the stressed situation of the power system network to accomplish efficient energy management without losing its reliability. On-line monitoring of power system stability has become a vital factor for electric utilities. An effective method for real-time monitoring of system status and thus voltage collapse prediction is described. The proposed technique investigates each line of the system through calculating an indicator that varies from 0 (no load condition) to 1 (maximum permissible loading condition). The basic concept of maximum power transfer through a line is utilised. The proposed contingency evaluation technique is applied on the IEEE 24 bus and IEEE 6 bus reliability test system and is found to be accurate in assessing the stressful status of the lines.

166 citations


Journal ArticleDOI
TL;DR: The Third Asia Pacific Symposium on Typhoid Fever and Other Salmonellosis was held in Bali, Indonesia on 8–10 December 1997.

146 citations


Journal ArticleDOI
TL;DR: In this article, the Modified Kent Eisenberg model was applied to predict the CO 2 loading in solutions of DEA and MDEA reported in the literature, and the results showed that the model was able to give a relatively good loading over a wide range of operating conditions both in solution of single and mixed amine.
Abstract: Equilibrium data on the absorption of CO 2 in aqueous solutions of single and mixed amine was analysed using the Modified Kent Eisenberg model. The experimental value of the equilibrium constant for the formation of carbamate, instead of the fitted value as usually used by other investigators, was applied in the analysis. Data on CO 2 loading in aqueous solutions of DEA and MDEA at various temperature (303–323 K) and CO 2 partial pressure (0.09–100kPa) obtained from a stirred reactor was fitted to generate the different parameters in the model. Using these constants, the model was applied to predict the CO 2 loading in solutions of DEA and MDEA reported in the literature. Prediction was also made on the loading in solutions of mixed DEA/MDEA obtained from experiments conducted over a range of composition (DEA:MDEA = 0–1) at different temperatures of 303–323 K, as well as those reported in the literature. In all cases, it was found that the model was able to give a relatively good CO 2 loading over a wide range of operating conditions both in solutions of single and mixed amine using the constants generated from single amine experiments. It also suggested that the experimental value of the equilibrium constant for the formation of carbamate obtained from an earlier work can be taken as the true value for the reaction.

141 citations


Journal ArticleDOI
TL;DR: A shift to proportionally less sulfate reduction in sediments of regenerating forests may result in greater availability of dissolved nutrients and some trace metals, and serve to reduce exposure of R. apiculata seedlings to anoxic, toxic solutes, and facilitate rapid seedling growth and regeneration of forests.

Journal ArticleDOI
TL;DR: The authors discusses educational development, focussing on curriculum changes and issues affecting the change in Malaysia and perspectives for the future, and discusses the issue of values education which is being taught in schools and the efforts of the government to mould a united Malaysian nation with Malaysian values, as well as an overview of current incentives and future perspectives for greater use of technology in the classroom.
Abstract: Discusses educational development, focussing on curriculum changes and issues affecting the change in Malaysia and perspectives for the future. Begins with an introduction that describes the school system in general, followed by a description of educational and curriculum development from independence to the present, highlighting the most current trends and changes Malaysia is undertaking. Concludes with discussions on the issue of values education which is being taught in schools and the efforts of the government to mould a united Malaysian nation with Malaysian values, as well as an overview of the current incentives and future perspectives for greater use of technology in the classroom.

Journal ArticleDOI
TL;DR: It is found that a premature infant with UDT is more likely to achieve full testicular descent at 1 year of age than a term infant and a premature baby with undescended testes is more than twice as likely to have congenital abnormalities of the external genitalia.
Abstract: In a study of 1,002 consecutive Malaysian male newborns, 48 (4.8%) were found to have undescended testes (UDT). The rate and laterality of the UDT were associated with lower birth weight (P < 0.001) and prematurity (P < 0.001). Boys with UDT were also more likely to have other congenital abnormalities of the external genitalia, the commonest being hydrocele. No correlation between UDT and maternal age, birth order, social class, or mode of delivery was demonstrated in this study. Although 26/34 (76.5%) of UDT achieved full spontaneous descent by 1 year of age, 1.1% of all infants whose testes remained undescended required regular long-term follow-up with surgical referral and correction at an appropriate time. A premature infant with UDT is more likely to achieve full testicular descent at 1 year of age than a term infant.

Journal ArticleDOI
TL;DR: In this paper, 19 alkaloids were isolated from the leaf extract of Kopsia griffithii, of which two were new, viz., 12-methoxypleiocarpine and the tetrahydro-β-carboline derivative, harmicine.

Journal ArticleDOI
TL;DR: Evaluate two new commercial tests for dengue serology, which showed excellent sensitivity and specificity and should be a useful aid in confirming the clinical diagnosis of d Dengue infection.

Journal Article
TL;DR: In this article, the authors reviewed the records of all patients who presented to the University Hospital in Kuala Lumpur with a definite history of foreign-body ingestion in the form of a dental prosthesis, and their respective radiographs reassessed.
Abstract: Objective: Impacted foreign bodies in the trachea and esophagus are common. In the esophagus, these are usually bones, while for the trachea, it is commonly some form of seed or nut. The incidence of impacted dental prostheses is not highlighted in the literature. They usually have a definite history of ingestion, frequently during trauma, seizures, or Sleep. Prompt management in a safe and effective manner is required if significant morbidity, and even mortality, is to be avoided. Method: The records of all patients who presented to the University Hospital in Kuala Lumpur with a definite history of foreign-body ingestion in the form of a dental prosthesis were reviewed, and their respective radiographs reassessed. Results: There were 21 patients with impacted dental prostheses from a total of 200 patients who had impacted foreign bodies (11.5). Indirect laryngoscopy detected five of these dentures, and in only seven were the dentures seen on plain radiography (33)-all of which had metal wires attached. Of the 21 patients, 16 had the foreign bodies removed endoscopically; 2 could not be removed and were allowed to pass through the gastrointestinal tract under close monitoring; and 3 whose dental prostheses were not detected and who subsequently passed the foreign bodies. Conclusions: Impacted dental prostheses appear to constitute a significant proportion of impacted foreign bodies in the orolaryngopharynx. The majority are radiolucent. In the presence of positive history or/and symptoms, endoscopic examination and removal is suggested if possible to reduce morbidity. No serious complications have been seen.

Journal ArticleDOI
TL;DR: The findings support the importance of the on-going national quality assurance programme to ensure doses are kept to a level consistent with optimum image quality and provide patient dosimetry information on healthcare level II countries.
Abstract: A collaborative national survey initiated by the University of Malaya and the Ministry of Health was conducted from 1993 to 1995 to establish baseline patient dose data for seven common types (12 projections) of X-ray examinations in Malaysia. A total of 12 randomly selected public hospitals and 867 patients were included in this survey. The entrance surface doses (ESD) received by the patients were measured using thermoluminescent dosemeters (TLDs) attached to the patient's skin. Histograms are presented showing wide, positively skewed distributions of measured entrance surface doses for each examination. Mean, median, first and third quartile values of ESD and median effective dose are reported. Survey results are generally comparable with those reported in the UK, USA and by the International Atomic Energy Agency (IAEA). The results also provide information on dose level for a lower weight population (mean weight 60 kg) compared with the international reference dose values based on a 70 kg standard. The findings support the importance of the on-going national quality assurance programme to ensure doses are kept to a level consistent with optimum image quality. The data will also be useful for the formulation of national guidance levels as recommended by the IAEA. Furthermore, this study provides patient dosimetry information on healthcare level II countries.

Journal ArticleDOI
TL;DR: In this article, an artificial neural network (ANN)-based network reconfiguration method is developed to solve the real power loss in distribution networks, which is an operation in configuration management that determines the switching operations for a minimum loss condition.

Journal ArticleDOI
TL;DR: In this article, the PEO-(NH 4 ) 2 SO 4 systems with different NH 4 + /EO ratio have been prepared by the solution-cast technique and investigated by X-ray diffraction, infrared spectroscopy and impedance spectrography.

Journal ArticleDOI
TL;DR: In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary Rice grains (60), glutinous Rice flour (48%) and corn flour (26%).
Abstract: In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary rice grains (60%), glutinous rice flour (48%) and corn flour (26%). All positive samples of ordinary rice and glutinous rice grains had total fungal counts below 103 cfu/g sample, while among the positive rice flour, glutinous rice flour and corn flour samples, the highest total fungal count was more than 103 but less than 104 cfu/g sample respectively. However, in wheat flour samples total fungal count ranged from 102 cfu/g sample to slightly more than 104 cfu/g sample. Aflatoxigenic colonies were mostly detected in wheat flour (20%), followed by ordinary rice grains (4%), glutinous rice grains (4%) and glutinous rice flour (2%). No aflatoxigenic colonies were isolated from rice flour and corn flour samples. Screening of aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 using reversed-phase HPLC were carried out on 84 samples of ordinary rice grains and 83 samples of wheat flour. Two point four percent (2.4%) of ordinary rice grains were positive for aflatoxin G1 and 3.6% were positive for aflatoxin G2. All the positive samples were collected from private homes at concentrations ranging from 3.69–77.50 μg/kg. One point two percent (1.2%) of wheat flour samples were positive for aflatoxin B1 at a concentration of 25.62 μ};g/kg, 4.8% were positive for aflatoxin B2 at concentrations ranging from 11.25–252.50 μg/kg, 3.6% were positive for aflatoxin G1 at concentrations ranging from 25.00–289.38 μg/kg and 13.25% were positive for aflatoxin G2 at concentrations ranging from 16.25–436.25 μg/kg. Similarly, positive wheat flour samples were mostly collected from private homes.

DOI
01 Jan 1998
TL;DR: A number of diversity indices highlight the low diversity of epifaunal taxa in the recently cleared site, perhaps a consequence of the drier substrate surface in the absence of a tree canopy.
Abstract: Malaysian mangroves harbour a high diversity of benthic invertebrates, including poly- chaetes, gastropods, brachyurans, and sipunculids. In three sites at different points in the forest harvest cycle at Matang, the density and biomass of epifaunal taxa was found to be greatest in mature Rhizophora apiculata Lamk. forest, intermediate in a 15-year old stand, and lowest in recently cleared forest. The pattern in infaunal taxa was found to be different, with the greatest density and biomass in the recently cleared site. A number of diversity indices highlight the low diversity of epifaunal taxa in the recently cleared site, perhaps a consequence of the drier substrate surface in the absence of a tree canopy.

Journal ArticleDOI
S A Sarji1, Bjj Abdullah1, G Kumar1, A H Tan1, P Narayanan1 
TL;DR: Claustrophobia in MRI is more of a problem among the educated individuals or patients from a higher socio-economic group, which may explain the higher incidence in Western European and North American patients.
Abstract: A recognized cause of incomplete or cancelled MRI examinations is anxiety and claustrophobic symptoms in patients undergoing MR scanning. This appears to be a problem in many MRI centres in Western Europe and North America, where it is said to be costly in terms of loss of valuable scan time, and has led to researchers suggesting several anxiety-reducing approaches for MRI. To determine the incidence of failed MRI examination among our patients and if there are any associations with a patient's sex, age and education level, we studied claustrophobia that led to premature termination of the MRI examination in the University Malaya Medical Centre (UMMC) in 3324 patients over 28 months. The incidence of failed MRI examinations due to claustrophobia in the UMMC was found to be only 0.54%. There are associations between claustrophobia in MRI with the patients' sex, age and level of education. The majority of those affected were male patients and young patients in the 25-45-years age group. The patients' education level appears to be the strongest association with failed MRI examinations due to claustrophobia, where the majority of the affected were highly educated individuals. Claustrophobia in MRI is more of a problem among the educated individuals or patients from a higher socio-economic group, which may explain the higher incidence in Western European and North American patients.

Journal ArticleDOI
01 Mar 1998
TL;DR: A series of machining experiments of Inconel 718 has been carried out using coated and uncoated carbides as discussed by the authors, where the effects of cutting variables (speed, feed and depth of cut) were described.
Abstract: A series of machining experiments of Inconel 718 has been carried out using coated and uncoated carbides. The paper describes the effects of cutting variables (speed, feed and depth of cut)...

Journal ArticleDOI
TL;DR: In this paper, a search for 57 Fe gamma rays of energy 14.4 keV induced by resonant absorption of monochromatic solar axions, as proposed by Moriyama, was made, and the proposed axions were suggested to be emitted from the Sun, in M1 transitions between the first, thermally excited state and the ground state of 57 Fe.

Journal ArticleDOI
TL;DR: The EtOH extract of the leaves of Holarrhena curtisii yielded five new steroidal alkaloids and eight compounds showed significant cytotoxic and leishmanicidal activities.
Abstract: The EtOH extract of the leaves of Holarrhena curtisii yielded five new steroidal alkaloids: 17-epi-holacurtine (3), 17-epi-N-demethylholacurtine (4), holacurtinol (5), 3alpha-amino-14beta-hydroxypregnan-20-one (7), and 15alpha-hydroxyholamine (8), in addition to the known compounds, holacurtine (1), N-demethylholacurtine (2), and holamine (6). All eight compounds showed significant cytotoxic and leishmanicidal activities.

Journal ArticleDOI
TL;DR: The coccids varied in their host-plant specificity from species that occurred in most of the sampled Macaranga to one species that was found almost exclusively only on a single host species.
Abstract: Myrmecophytic species of the Paleotropical plant genus Macaranga (Euphorbiaceae) have hollow stems that are almost always occupied by ants of the genus Crematogaster and scale insects of the family Coccidae (Hemiptera: Coccoidea). The coccids have a cryptic endophytic lifestyle and are confined to this microhabitat. They are much more diverse than previously recognised. First data are presented on the diversity, prevalence, specificity and distribution of the coccids associated with myrmecophytic Macaranga species. Twenty-two species of Coccidae in total, including 15 previously unknown from Macaranga, were disco- vered from 19 species of Macaranga in Peninsular Malaysia and Borneo. The ori- ginal describers tentatively assigned the known coccid species to Coccus (Coccinae) but the Macaranga coccids still require taxonomic research to establish their correct placing. The coccids varied in their host-plant specificity from species that occurred in most of the sampled Macaranga to one species that was found almost exclusively only on a single host species. In addition to their occurrence on Macar- anga, only three species, C. macarangae and C. secretus and morphospecies C. 214 were found on rare occasions in the stem interior of a few other myrmecophytes and in a non-myrmecophytic liana, but did not regularly colonise these plants. Most of the coccids can be regarded as highly specific at the plant genus level.

Journal ArticleDOI
TL;DR: This study on the startup and steady‐state operation of a UASB reactor shows that its fluid flow can be explained just as well with a simple axial dispersion model.
Abstract: Fluid flow in UASB reactors is usually described by multicompartment models consisting of separate ideally mixed zones, plug flow zones, and stagnant zones linked with bypassing flows and back-mixing flows. A closer look at UASB reactor behavior indicates that this complexity is unnecessary. Our study on the startup and steady-state operation of a UASB reactor shows that its fluid flow can be explained just as well with a simple axial dispersion model. The physical transitions, which occur in different zones of the UASB reactor as the microorganisms acclimate to the wastewater, are adequately described by the model. Further, the number of parameters, which is six in standard UASB reactor models, is reduced to four in the case of the axial dispersion model.

Journal ArticleDOI
TL;DR: An indigenous strain of the purple non-sulphur phototrophic bacterium, Rhodopseudomonas palustris strain B1, was selected for the utilization and treatment of wastewater from a sago-starch-processing decanter and a cell yield of about 0.59g dry weight cell/g COD was obtained.
Abstract: An indigenous strain of the purple non-sulphur phototrophic bacterium, Rhodopseudomonas palustris strain B1, was selected for the utilization and treatment of wastewater from a sago-starch-processing decanter. Growth of Strain B1 under anaerobic‐light conditions in the carbohydrate-rich effluent was optimized by using 50% (v/v) effluent diluted in a basal minimal mineral medium with the addition to 0.1% (w/v) yeast extract. The optimum level of nitrogen source supplement, ammonium sulphate, was 1.0 g/l. Highest cell mass concentration was achieved by using tungsten lamps as the light source with a light intensity of 4 klux. Under these optimal conditions, a maximum biomass of about 2.5 g dry cell/l with a pigment content of about 1.1 mg carotenoid/g dry weight cell was achieved after 96 h of anaerobic cultivation. There was a 77% reduction in the chemical oxygen demand (COD) of the effluent. A cell yield of about 0.59 g dry weight cell/g COD was obtained.

Journal ArticleDOI
TL;DR: The diversity of monogeneans from Southeast Asia was examined using information from the literature to show their diversity at different taxonomic levels, and Malayan fauna is considered to be representative of the Southeast Asian fauna.

Journal Article
TL;DR: An open comparative randomised study comparing the performance of hydrocolloid dressings (DuoDERM CGF) to saline gauze dressings in the treatment of pressure ulcers was done to evaluate the overall dressing performance, wound healing and cost effectiveness.
Abstract: An open comparative randomised study comparing the performance of hydrocolloid dressings (DuoDERM CGF) to saline gauze dressings in the treatment of pressure ulcers was done to evaluate the overall dressing performance, wound healing and cost effectiveness. Thirty-four subjects were enrolled at the University Hospital, Kuala Lumpur over a 643 days period. Inclusion criteria were Stage II or III pressure ulcers, at least 18 years of age and written informed consent. Only one pressure ulcer per subject was enrolled in the study. Patients with infected pressure ulcers, diabetes mellitus, an immuno-compromised status and known sensitivity to the study dressings were excluded. Subjects who met the enrollment criteria were randomised to one of the two dressing regimes. They were expected to participate in the study for a maximum of eight weeks or until the pressure ulcer healed, which ever occurred first. Overall subject age averaged 58 years and the mean duration of pressure ulcer existence was about 1 month. Twenty-one of the thirty-four ulcers enrolled were stage II and thirteen were stage III. The majority of the ulcers (88%) were located in the sacral area and seventeen subjects (50%) were incontinent. In the evaluation of dressing performance in terms of adherence to wound bed, exudate handling ability, overall comfort and pain during dressing removal; all favoured the hydrocolloid dressing by a statistically significant margin (p < 0.001). Subjects assigned the hydrocolloid dressing experienced a mean 34% reduction from their baseline surface area measurement compared to a mean 9% increase by subjects assigned gauze dressings. This was not statistically significant (p = 0.2318). In cost evaluation of the study products, there was no statistical significance in the total cost of wound management per subject. When only labour time and cost was evaluated, there was a statistically significant advantage towards hydrocolloid dressings.