Rattan (Calamoideae) abundance and above-ground biomass at a primary rainforest of Peninsular Malaysia

Background: Rattans are widespread throughout paleo-tropical forests; however, there is no information on their contribution to above-ground biomass (AGB).

Aims: This study established biomass baseline values for 11 different rattan species in a Malaysian primary forest, and calculated the overall rattan AGB contribution and dynamics during two years.

Methods: All rattan stems in five 100 m × 100 m study plots were counted in 2011 and 2013. Biometric non-invasive measurements were carried out on 11 climbing and non-climbing species and total rattan biomass for both years calculated was compared.

Results: Rattans contributed with 3.1 Mg ha^?1 to the forest AGB. There was no significant change in rattan biomass between the years.

Conclusions: These preliminary results are the first published on the AGB contribution of rattans to Malaysian primary forests. Further studies are required to ascertain values across forest types and over time to reliably estimate the contribution of rattan species to ABG and carbon sequestration.     

A sex pheromone‐baited trapping system for management of sweetpotato weevil,Cylas formicarius (Coleoptera: Brentidae)

A potent male attractant of sweetpotato weevil helps in monitoring and control of sweetpotato weevil in many production areas around the world. At present, it has not been used in Malaysia. Cost of the components of a trapping system is a major constraint in the adoption of male lure‐baited trapping by growers in Malaysia. Seven field trapping experiments were conducted from February 2013 to November 2015 as part of an effort to develop a simple, easy to construct, cost‐effective and efficient sex pheromone‐baited trap acceptable for use by farmers in Malaysia for monitoring and control of sweetpotato weevil (Cylas formicarius Fabricius). Overall, sweetpotato weevil trap catch was significantly affected by the number of windows in the trap, the killing agent used in the trap and the position of the trap relative to sweetpotato foliage, while trap size and trap colour did not significantly affect trap catch. Trap catch was best in plastic pole traps made from polyethylene terephthalate, with four window opening to facilitate weevil entry, with detergent solution as a killing agent and with the trap positioned from 0 to 40 cm above the crop canopy level. In a comparison study with commercial trap designs, sex pheromone‐baited plastic pole traps caught 60%–78% more weevils than were caught in sex pheromone‐baited delta traps, wing traps or unitraps. Optimization of trap characteristics is important for improving the performance of pheromone‐baited traps for use in population monitoring or mass‐trapping efforts to minimize crop damage by sweetpotato weevil infestation.     

Evidence of Enhanced Ion Transport in Li‐Rich Silicate Intercalation Materials

The silicate compounds Li₂MSiO₄ (where M = Mn, Fe, Co) have received significant attention recently as Li intercalation electrodes. Overwhelmingly they exhibit relatively poor kinetics of ion intercalation. By synthesizing Li‐rich solid solutions of the form Li_2+2x Fe_1?x SiO₄ (with 0 ≤ x ≤ 0.3), the structural requirements for fast ion transport and hence relatively fast intercalation have been identified. Specifically the presence of additional Li⁺ in interstitial sites, not normally occupied in the stoichiometric Li₂FeSiO₄ compound, enhances ion transport by more than two orders of magnitude. The results, obtained by combining electrochemical measurements, with powder X‐ray and neutron diffraction and atomistic modeling of the ion dynamics, provide valuable guidance in designing future intercalation electrodes with high Li‐ion transport and, hence, fast electrode kinetics.     

The Leishmania promastigote surface antigen-2 (PSA-2) is specifically recognised by Th1 cells in humans with naturally acquired immunity to L. major

The promastigote surface antigen-2 (PSA-2) is a Leishmania parasite antigen, which can induce Th1-mediated protection against murine leishmaniasis when used as a vaccine. To evaluate PSA-2 as a human vaccine candidate the specific T-cell response to PSA-2 was characterised in individuals immune to cutaneous leishmaniasis. Peripheral blood mononuclear cells from Sudanese individuals with a past history of self-healing cutaneous leishmaniasis proliferated vigorously in response to PSA-2 isolated from Leishmania major, whereas the antigen did not activate cells from presumably unexposed Danes. Peripheral blood mononuclear cells from individuals with previous L. major infection had varying proliferative responses to PSA-2 derived from L. donovani promastigotes. Peripheral blood mononuclear cells activated by PSA-2 from L. major produced high amounts of interferon-γ and tumour necrosis factor-β, and little interleukin-4, thereby showing a Th1 cytokine pattern. Parallel cultures showed clear Th1 and Th2 response patterns to purified protein derivative of tuberculin or tetanus toxoid, respectively. Flow cytometric analysis revealed that PSA-2 induced blastogenesis in the CD3 positive population and that these cells were the major source of interferon-γ. The results show that Th1-like cells recognising PSA-2 are expanded during infection by L. major and that they maintain their Th1-like cytokine profile upon reactivation in vitro. Since immunity to cutaneous leishmaniasis is mediated by antigen-specific Th1-like cells, PSA-2 might be considered a vaccine candidate for human leishmaniasis.     

Migratory birds travelling to Bangladesh are potential carriers of multi-drug resistant Enterococcus spp., Salmonella spp., and Vibrio spp.

Antimicrobial resistance (AMR) is a major health crisis globally. Migratory birds could be a potential source for antibiotic resistant (ABR) bacteria. Not much is known about their role in the transmission of ABR in Bangladesh. In this study, a total of 66 freshly dropped fecal materials of migratory birds were analyzed. Bacterial isolation and identification were based on cultural properties, biochemical tests, and polymerase chain reaction (PCR). The disk diffusion method was employed to evaluate antibiogram profiles. By PCR, out of 66 samples, the detection rate of Enterococcus spp. (60.61%; 95% confidence interval: 48.55–71.50%) was found significantly higher than Salmonella spp. (21.21%; 95% CI: 13.08–32.51%) and Vibrio spp. (39.40%; 95% CI: 28.50–51.45%). Enterococcus isolates were frequently found resistant (100–40%) to ampicillin, streptomycin, meropenem, erythromycin, and gentamicin; Salmonella isolates were frequently resistant (72–43%) to chloramphenicol, tetracycline, ampicillin, streptomycin, and erythromycin; and Vibrio spp. isolates were frequently resistant (77–31%) to vancomycin, ampicillin, erythromycin, tetracycline, and streptomycin. In addition, 60% (95% CI: 44.60–73.65%) Enterococcus spp., 85.71% (95% CI: 60.06–97.46%) Salmonella spp., and 76.92% (95% CI: 57.95–88.97%) Vibrio spp. isolates were multi-drug resistant (MDR) in nature. Three isolates (one from each bacterium) were found resistant against six classes of antibiotics. The bivariate analysis revealed strong associations (both positive and negative) between several antibiotic pairs which were resistant to isolated organisms. To the best of our knowledge, this is the first study in detecting MDR Enterococcus spp., Salmonella spp., and Vibrio spp. from migratory birds travelling to Bangladesh. Frequent detection of MDR bacteria from migratory birds travelling to Bangladesh suggests that these birds have the potential to carry and spread ABR bacteria and could implicate potential risks to public health. We recommend that these birds should be kept under an AMR surveillance program to minimize the potential risk of contamination of the environment with ABR as well as to reduce their hazardous impacts on health.     

Flavokawain C Inhibits Cell Cycle and Promotes Apoptosis,Associated with Endoplasmic Reticulum Stress and Regulation of MAPKs and Akt Signaling Pathways in HCT 116 Human Colon Carcinoma Cells

Flavokawain C (FKC) is a naturally occurring chalcone which can be found in Kava (Piper methysticum Forst) root. The present study evaluated the effect of FKC on the growth of various human cancer cell lines and the underlying associated mechanisms. FKC showed higher cytotoxic activity against HCT 116 cells in a time- and dose-dependent manner in comparison to other cell lines (MCF-7, HT-29, A549 and CaSki), with minimal toxicity on normal human colon cells. The apoptosis-inducing capability of FKC on HCT 116 cells was evidenced by cell shrinkage, chromatin condensation, DNA fragmentation and increased phosphatidylserine externalization. FKC was found to disrupt mitochondrial membrane potential, resulting in the release of Smac/DIABLO, AIF and cytochrome c into the cytoplasm. Our results also revealed that FKC induced intrinsic and extrinsic apoptosis via upregulation of the levels of pro-apoptotic proteins (Bak) and death receptors (DR5), while downregulation of the levels of anti-apoptotic proteins (XIAP, cIAP-1, c-Flip_L, Bcl-xL and survivin), resulting in the activation of caspase-3, -8 and -9 and cleavage of poly(ADP-ribose) polymerase (PARP). FKC was also found to cause endoplasmic reticulum (ER) stress, as suggested by the elevation of GADD153 protein after FKC treatment. After the cells were exposed to FKC (60μM) over 18hrs, there was a substantial increase in the phosphorylation of ERK 1/2. The expression of phosphorylated Akt was also reduced. FKC also caused cell cycle arrest in the S phase in HCT 116 cells in a time- and dose-dependent manner and with accumulation of cells in the sub-G1 phase. This was accompanied by the downregulation of cyclin-dependent kinases (CDK2 and CDK4), consistent with the upregulation of CDK inhibitors (p21^Cip1 and p27^Kip1), and hypophosphorylation of Rb.     

Inhibitory and Resistance-Modifying Potential of Plant-Based Alkaloids Against Methicillin-Resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> (MRSA)

Increased prevalence of methicillin-resistant Staphylococcus aureus (MRSA) has become a major threat to the health sector worldwide due to their virulence, limited therapeutic options and their distribution in both hospital and community settings. Discovery and development of new anti-MRSA agents as alternatives to the very few antibiotics left in the armamentarium are, thus, urgently required. Recently, an efflux mechanism in MRSA has been identified as one of the main contributors of resistance towards various structurally unrelated antibiotics. The potential of reserpine (a phytoalkaloid) as efflux pump inhibitor (EPI) against various microbes remains limited as the concentration needed for inhibition is toxic to humans. This study therefore aimed to evaluate 13 alkaloid compounds as potential inhibitory agents and/or potential EPIs against a panel of three MRSA isolates which not only differ in their susceptibility to vancomycin (amongst the last drugs available to treat serious MRSA infection), but also exhibited active efflux activity. Results indicated berberine’s moderate inhibitiory activity against two MRSA isolates scoring a minimum inhibitory concentration (MIC) value of 125 μg/ml. Notable efflux inhibitory activity (ranging from two- to eightfold Ethidium Bromide MIC reduction) meanwhile was detected from quinine, piperine and harmaline using reserpine as the positive control. Findings from this study support the opinion that a vast number of potential phytocompounds with pharmacological potential await discovery. Therapeutic application of these compounds, however, warrants further investigation to ascertain their pharmacodynamics and safety aspects. This study was supported by the FRIM’s Young Scientist Grant No. 40-300-40-3007 and the Intensified Research in Priority Areas (IRPA) Grant No. 30-300-40-3010 from the Ministry of Science, Technology and Innovation, Malaysia.     

Development of anti-acanthamoebic approaches

International Microbiology - Acanthamoeba keratitis is a sight-endangering eye infection, and causative organism Acanthamoeba presents a significant concern to public health, given escalation of...     

Crumbs and the apical spectrin cytoskeleton regulate R8 cell fate in the Drosophila eye

The Hippo pathway is an important regulator of organ growth and cell fate. In the R8 photoreceptor cells of the Drosophila melanogaster eye, the Hippo pathway controls the fate choice between one of two subtypes that express either the blue light-sensitive Rhodopsin 5 (Hippo inactive R8 subtype) or the green light-sensitive Rhodopsin 6 (Hippo active R8 subtype). The degree to which the mechanism of Hippo signal transduction and the proteins that mediate it are conserved in organ growth and R8 cell fate choice is currently unclear. Here, we identify Crumbs and the apical spectrin cytoskeleton as regulators of R8 cell fate. By contrast, other proteins that influence Hippo-dependent organ growth, such as the basolateral spectrin cytoskeleton and Ajuba, are dispensable for the R8 cell fate choice. Surprisingly, Crumbs promotes the Rhodopsin 5 cell fate, which is driven by Yorkie, rather than the Rhodopsin 6 cell fate, which is driven by Warts and the Hippo pathway, which contrasts with its impact on Hippo activity in organ growth. Furthermore, neither the apical spectrin cytoskeleton nor Crumbs appear to regulate the Hippo pathway through mechanisms that have been observed in growing organs. Together, these results show that only a subset of Hippo pathway proteins regulate the R8 binary cell fate decision and that aspects of Hippo signalling differ between growing organs and post-mitotic R8 cells.     

Polyesters Based on Linoleic Acid for Biolubricant Basestocks: Low-Temperature,Tribological and Rheological Properties

Presently, plant oils which contain high percentage of linoleic acid 1 are perceived to be a viable alternative to mineral oil for biolubricant applications due to their biodegradability and technical properties. In order to get biodegradable lubricant, triester derivatives compounds (1–5) were synthesized and characterized. The processes involved were monoepoxidation of linoleic acid 2, oxirane ring opening 3, esterification 4 and acylation 5. The structures of the products were confirmed by FTIR, ¹H and ¹³C-NMR and LC-MS. The results that showed lowest temperature properties were obtained for triester 5, with a pour point value (PP) of -73°C, highest onset temperature (260°C) and lowest volatility at 0.30%. Viscosity index (VI) increased for the ester’s synthetic compounds (2, 3, 4, 5), while the PP decreased. This behavior is the result of the increase of the chain length of the branching agents. Triester based linoleic acid has improved properties such as low-temperature and tribological properties. These results will make it feasible for plant oil to be used for biolubricants, fuels in chain saws, transmission oil and brake fluid.