How to look for new drugs? What guidelines to use? Have we to continue investigations on plant and marine organisms? These questions arise frequently today. A pharmacological effect results from the addition of many effects at a molecular level, i.e. the interaction between a ligand and a receptor. As long as the chemical structure of this receptor remains unknown, studies of Nature's resources will yield the largest reservoir of new drugs. Nature provides our imagination with the pattern of novel biologically active molecules. Criteria classically used in the past to select plants for study were chemotaxonomy, ethnopharmacology or pharmacotaxonomy. Examples will be taken from personal experience, to illustrate work done according to the chemotaxonomical approach (Ochrosia and ellipticines), and the ethnopharmacological approach (antiinflammatory properties of Euphorbiaceae from New Caledonia). Taking into account that one of the major problems we have to face is the unsatisfactory classical pharmacological testing procedure, we have tried to set up a network grouping biologists and chemists. Among many results obtained, one concerns the use of the mammalian hypothalamo-pituitary system to screen effects of alkaloids extracted from Psychotria oleoides, a Rubiaceae collected in New Caledonia. Psycholeine exhibits an intriguing activity on GH release. Another result concerns the influence of a Labiatae extract on the adenylate cyclase system: 9 HODE extracted from Glechoma hederacea stimulates the basal level of enzyme activity in platelets, this activity being possibly involved in the folk uses claimed. Using the tubulin test to screen antimitotic activities of plant extracts, the biological activity of rhazinilam has been demonstrated as responsible for the antitubulin activity of a Malaysian plant, Kopsia singapurensis.(ABSTRACT TRUNCATED AT 250 WORDS)
An overview of the Oriental species of Cleruchus Enock (Hymenoptera: Mymaridae) is given, and its five newly described species as well as one undescribed species from Malaysia are keyed. The described new taxa are C. funiculatus Manickavasagam Palanivel sp. n., C. indicus Manickavasagam Palanivel sp. n. and C. orientalis Manickavasagam Palanivel sp. n., all from India, C. blimp Triapitsyn sp. n. from Brunei, and C. pmilb Triapitsyn sp. n. from Thailand. Anaphes quinquearticulatus Huber Triapitsyn is newly reported from India.
Seven species of Strongylophthalmyia are described as new species: Strongylophthalmyia armipes n. sp. (Malaysia), S. biloba n. sp. (Indonesia), S. bukittinggiana n. sp. (Indonesia), S. minutissima n. sp. (Thailand), S. prominens n. sp. (Vietnam), S. strigosa n. sp. (China), S. vichrevi n. sp. (Russia). New data on morphology and distribution of S. bifasciata Yang et Wang 1992 and S. malayensis Evenhuis, 2016 are provided.
Bangithrips mei gen. et sp. n. is described from Peninsular Malaysia. The significance is discussed of outstanding structural autapomorphies that are commonly used in classifications of Thysanoptera. Argyrothrips ommatos described recently from northern Australia is recorded from Malaysia.
The selection of curve number to represent watersheds with similar land use and land cover is often subjective and ambiguous. Watershed with several soil groups further complicates curve number selection process while wrong curve number selection often produces unrealistic runoff estimates. The 1954 simplified Soil Conservation Services (SCS) runoff model over-predicted runoff with significant amount and further magnified runoff prediction error toward higher rainfall depths in this study. The model was statistically insignificant with the rejection of two null hypotheses and paved the way for regional model calibration study. This paper proposes a new direct curve number derivation technique from the given rainfall-runoff conditions under the guide of inferential statistics. The technique offers a swift and economical solution to improve the runoff prediction ability of the SCS runoff model with statistically significant results. A new rainfall-runoff model was developed with calibration according to the regional hydrological conditions. It out-performed the runoff prediction of the simplified SCS runoff model and the asymptotic runoff model. The derived curve number = 89 at alpha = 0.01 level. The technique can be adopted to predict flash flood and forecast urban runoff.
We collected two specimens of an undescribed species of Lygosoma from pitfall traps in an urban rainforest in Kuching and from the base of a forested hill in western Sarawak, East Malaysia. The new species is diagnosable from all south-east Asian congeners by morphological characters, and most closely resembles Lygosoma herberti from the Thai-Malay Peninsula. The new species shows substantial molecular divergence from its closest relatives in two protein-coding genes, one mitochondrial (ND1) and one nuclear (R35) that we sequenced for several south-east Asian congeners. We describe the new species on the basis of this distinct morphology and genetic divergence. It is the third species of Lygosoma known from Borneo, and highlights the continuing rise in lizard species diversity on the island. In addition, the discovery of this species from a small urban rainforest underscores the importance of preserving intact rainforest areas of any size in maintaining species diversity.
Two new species, Phlegmariurus iminii Kiew (Lycopodiaceae) from limestone karst and P. monticola Kiew from montane habitats, are described from Peninsular Malaysia and a new combination is made for Phlegmariurus pinifolius (Trevis.) Kiew. Phlegmariurus iminii, known from a single hill threatened by quarrying, is Critically Endangered; while P. monticola and P. pinifolius that are relatively widespread are of Least Concern.
Simulating Lotka-Volterra model using a numerical method requires the researcher to apply tiny mesh sizes to come up with an accurate solution. This approach will increase the complexity and burden of computer memory and consume long computational time. To overcome these issues, a new solver is used that could simulate Lotka-Volterra model using bigger mesh size. In this paper, prey and predator behaviour is simulated via Lotka-Volterra model. We approximate the nonlinear terms in the model via weighted average approach and differential equation via nonstandard denominators. We provide three new schemes for one step method and simulate four sets of parameters to examine the performance of these new schemes. Results show that these new schemes simulate better for large mesh sizes.
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.
Carbon nanotubes (CNTs) possess outstanding properties that could be useful in several technological, drug delivery, and diagnostic applications. However, their unique physical and chemical properties are hindered due to their poor solubility. This article review's the different ways and means of solubility enhancement of single-wall carbon nanotubes (SWNTs). The advantages of SWNTs over the multi-walled carbon nanotubes (MWNTs) and the method of non-covalent modification for solubility enhancement has been the key interest in this review. The review also highlights a few examples of dispersant design. The review includes some interesting utility of SWNTs being wrapped with polymer especially in biological media that could mediate proper drug delivery to target cells. Further, the use of wrapped SWNTs with phospholipids, nucleic acid, and amphiphillic polymers as biosensors is of research interest. The review aims at summarizing the developments relating to wrapped SWNTs to generate further research prospects in healthcare.
The genus Molpa Walker was previously considered to be disjunctly distributed in broad-leaf rain forests in India and Malaysia. Here we report one new species Molpa dulongensis sp. nov. from subtropic broad-leaf rain forests in southwestern Yunnan Province in China. This is a part of the Indo-Burma biodiversity hotspot area. So we can infer that Molpa is continuously distributed in broad-leaf rain forests found in Oriental Region. Redescription of the genus Molpa and description of the new species Molpa dulongensis sp. nov. are provided. The types are deposited in Insect Collection of Institute of Zoology, Chinese Academy of Sciences, Beijing, China (IZCAS).
Leech infestation in otolaryngology is sporadically seen in
remote area of tropical countries, but the cases are usually not
scientifically reported. We are reporting an unusual case of a
land leech removal from external auditory canal (EAC).