Diversity of tree flora of the catchments of Hiyare reservoir

Hiyare forest which acts as the catchments of the Hiyare man-made reservoir, is located in the Galle district of Sri Lanka. It spans in an area of 243 ha and is an extension of Kottawa- Kombala forest reserve. This study was focused on the diversity of tree species and the floristic structure of the catchments of Hiyare reservoir.Sampling was carried out in the catchments of Hiyare reservoir using randomly placed twenty, 20 m × 20 m plots. Diameter at breast height (dbh) of all 'trees' - single, woody stems ≥ 5 cm dbh, were measured in each plot. Relative frequency, relative density, relative basal area, important value index (IVI) were calculated to identify dominant plant species/families. Shannon diversity index and Simpson's index were calculated and multivariate statistical approach was used to identify floristic communities in the study site. Two 100 m line transects were placed randomly and all plant species (> 1 m height) encountered on transects were recorded to produce profile diagrams. Voucher specimens of sampled trees were collected to confirm the identificationThe study revealed a total of 1055 individuals belonging to 71 tree species of 47 genera and 27 plant families. Among them were 36 endemic species. Three most dominant tree species based on IVI values were Dipterocarpus zeylanicus, Myristica dactyloides and Anisophyllea cinnamomoides. Dipterocarpus zeylanicus exhibited a localized distribution while Myristica dactyloides and Anisophyllea cinnamomoides were widespread in the forest. Dipterocarpaceae, Anacardiaceae and Clusiaceae were recorded as the three most dominant plant families in Hiyare forest. Shannon Diversity index and Simpson's index of Hiyare forest were 1.543 and 0.013 respectively which indicated less species diversity and higher dominance compared to other lowland rain forests of the country. The study revealed seven nationally threatened species, five near threatened species and eleven globally threatened species. Of the recorded species, 28.2% were medicinally important. Cluster analysis and principal component analysis revealed presence of two distinct plant communities. A comprehensible vertical stratification was observed in profile diagrams and more trees were abundant in the sub canopy (10-20 m) and understory strata (5-10 m). Considering the dominant species recorded at different strata, Hiyare forest was recognized to be similar to Vitex-Dillenia-Chaetocarpus-Anisophyllea community identified by de Rosayro in 1942 and was inferred to be in the early successional phase of a lowland primary forestHiyare forest is vital for the sustenance of the Hiyare reservoir. The site at present is used for recreation purposes. Further research on floristic would enable better conservation and management of the Hiyare forest and the reservoir

Record of point endemic Balanocarpus kitulgallensis Kosterm and its morphological affinities with related species

Balanocarpus kitulgallensis Kosterm. (Family Dipterocarpaceae) is a point endemic, critically endangered tree species first recorded from the type locality Kithulgala, Sri Lanka in 1992 by Kostermans. However, since its discovery this species has not been observed at the recorded locality and considered to be an extinct species or misidentified with another Dipterocarp. The type specimen or any collections of B. kitulgallensis are not available at the National Herbarium Peradeniya at present. Taxonomy of this species also has been contradictory. This study focused on the confirmation of the record and the taxonomic status of B. kitulgallensis and assessing its morphological characters with closely related coexisting speciesField sampling was conducted mainly in the Kithulgala, Sinharaja, Dolukanda and Kanneliya Forest Reserves during Januray to May 2009. A detailed morphological analysis was performed using B. kitulgallensis and several other closely related species; Balanocarpus brevipetiolaris, Hopea jucunda and Hopea modesta. Most distinct vegetative and reproductive characters were recorded and scored. Cluster analysis and principal component analysis was carried out using PC-ORD v 4.0.A viable population of B. kitulgallensis was observed at the same previously recorded location, near „Makulu Ella‟ across the Kelaniya river opposite to the Kithulgala Resthouse (6.988895°N, 80.401873°E). Recorded population consists of over 150 individuals and most of the individuals were in the seedling and sapling stage. Only a few mature individuals were observed in fruiting stage. Vegetative and reproductive characters of the recorded specimens confirmed the present taxonomic status of B. kitulgallensis and rejected its placement in the genus Hopea of Dipterocarpaceae. Analysis revealed the high vegetative morphological similarity between B. kitulgallensis and Hopea modesta, a Dipterocarp species that coexists at the same locality. However, fruit characters of these two species are very important for accurate identification of these species in the field. Results of the study also provide evidence that vegetative characters can mislead accurate species identification of the Dipterocarp species in Sri Lanka

Cationic amino acid transporters play key roles in the survival and transmission of apicomplexan parasites

© 2017 The Author(s). Apicomplexans are obligate intracellular parasites that scavenge essential nutrients from their hosts via transporter proteins on their plasma membrane. The identities of the transporters that mediate amino acid uptake into apicomplexans are unknown. Here we demonstrate that members of an apicomplexan-specific protein family-the Novel Putative Transporters (NPTs)-play key roles in the uptake of cationic amino acids. We show that an NPT from Toxoplasma gondii (TgNPT1) is a selective arginine transporter that is essential for parasite survival and virulence. We also demonstrate that a homologue of TgNPT1 from the malaria parasite Plasmodium berghei (PbNPT1), shown previously to be essential for the sexual gametocyte stage of the parasite, is a cationic amino acid transporter. This reveals a role for cationic amino acid scavenging in gametocyte biology. Our study demonstrates a critical role for amino acid transporters in the survival, virulence and life cycle progression of these parasites

Simulating NIRS and MRS Measurements During Cerebral Hypoxia-Ischaemia in Piglets Using a Computational Model

We present a group analysis of the changes in cerebral haemodynamics, and the oxidation state of cytochrome-c-oxidase measured using broadband near-infrared spectroscopy (NIRS) and intracellular pH measured by phosphorous ((31)P) magnetic resonance spectroscopy (MRS) during and after cerebral hypoxia-ischaemia (HI) in 15 piglets. We use a previously published computational model of cerebral metabolism in the piglet [1] to integrate these measurements and simulate HI. We successfully simulate changes in cellular metabolism including shifts in intracellular pH observed in the piglet brain during HI. In this process, we optimise physiological parameters in the model identified through sensitivity analysis (such as the rate of glucose metabolism and intracellular lactate concentration), to fit simulated and measured data. The model fits the data reasonably and suggests a 20 % drop in glucose consumption, a ~65 % increase in lactate concentration and ~35 % drop in the cerebral metabolic rate of oxygen (CMRO₂) during HI

Entomologic and Virologic Investigation of Chikungunya, Singapore

Data from longitudinal analyses can be useful in the design and implementation of control strategies

Evaluation of Chikungunya Diagnostic Assays: Differences in Sensitivity of Serology Assays in Two Independent Outbreaks

Chikungunya is a mounting public health concern in many parts of the world. Definitive diagnosis is critical in differentiating the diseases, especially in dengue endemic areas. There are some commercial chikungunya kits and published molecular protocols available, but no comprehensive comparative evaluation of them was performed. Using sera collected in outbreaks caused by two variants of Chikungunya virus (A226 and 226V), we tested 2 commercial IgM tests (CTK lateral flow rapid test and EUROIMMUN IFA) alongside our in-house IgM assays (using both variants of the virus). Sensitivities of 2 published PCR protocols were also evaluated based on RNA standards derived from cell-cultured viruses. The commercial assays had different performances in each outbreak, with CTK's lateral flow test having the best performance in the first outbreak and EUROIMMUN IFA being more sensitive in the second outbreak. Use of the current circulating virus in a test assay improves sensitivity of the MAC-ELISAs. For PCR, a probe-based real time RT-PCR method was found to be 10 times more sensitive than the SYBR Green method. Despite this, the latter protocol is found to be more suitable and cost-effective for our diagnostic laboratory. This evaluation demonstrates the importance of appraisal of commercial kits and published protocols before application of a diagnostic tool in the clinical and operational setting

Pre-elimination stage of malaria in Sri Lanka: assessing the level of hidden parasites in the population

<p>Abstract</p> <p>Background</p> <p>With the dramatic drop in the transmission of malaria in Sri Lanka in recent years, the country entered the malaria pre-elimination stage in 2008. Assessing the community prevalence of hidden malaria parasites following several years of extremely low transmission is central to the process of complete elimination. The existence of a parasite reservoir in a population free from clinical manifestations, would influence the strategy for surveillance and control towards complete elimination.</p> <p>Methods</p> <p>The prevalence of hidden parasite reservoirs in two historically malaria endemic districts, Anuradhapura and Kurunegala, previously considered as high malaria transmission areas in Sri Lanka, where peaks of transmission follow the rainy seasons was assessed. Blood samples of non-febrile individuals aged five to 55 years were collected from randomly selected areas in the two districts at community level and a questionnaire was used to collect demographic information and movement of the participants. A simple, highly sensitive nested PCR was carried out to detect both <it>Plasmodium falciparum </it>and <it>Plasmodium vivax</it>, simultaneously.</p> <p>Results</p> <p>In total, 3,023 individuals from 101 villages participated from both districts comprising mostly adults between the ages 19-55 years. Out of these, only about 1.4% of them (n = 19) could recall having had malaria during the past five years. Analysis of a subset of samples (n = 1322) from the two districts using PCR showed that none of the participants had hidden parasites.</p> <p>Discussion</p> <p>A reservoir of hidden parasites is unlikely to be a major concern or a barrier to the ongoing malaria elimination efforts in Sri Lanka. However, as very low numbers of indigenous cases are still recorded, an island-wide assessment and in particular, continued alertness and follow up action are still needed. The findings of this study indicate that any future assessments should be based on an adaptive sampling approach, involving prompt sampling of all subjects within a specified radius, whenever a malaria case is identified in a given focus.</p

Chikungunya as a cause of acute febrile illness in southern Sri Lanka

10.1371/journal.pone.0082259PLoS ONE812-POLN

A Simple Approach to Assign Disulfide Connectivity Using Extracted Ion Chromatograms of Electron Transfer Dissociation Spectra

Increasing interest in production of protein-based pharmaceuticals (biotherapeutics) is accompanied by an increased need for verification of protein folding and correct disulfide bonding. Recombinant protein expression may produce aberrant disulfide bonds and could result in safety concerns or decreased efficacy. Thus, the thorough analysis of disulfide bonding is a necessity for protein therapeutics. The use of ETD facilitates this analysis because disulfide bonds are preferentially cleaved when subjected to ETD. Here, we make use of this well-characterized reaction to assign disulfide bonding networks by coupling the use of extracted ion chromatograms (XICs) of cysteine-containing peptides with ETD analysis to produce an efficient assignment approach for disulfide bonding. This method can be used to assign a disulfide pattern in a de novo fashion, to detect disulfide shuffling, and to provide information on heterogeneity, when more than one disulfide bonding pattern is present. The method was applied for assigning the disulfide-bonding network of a recombinant monomer of the HIV envelope protein gp120. It was found that one region of the protein, the V1/V2 loops, had significant heterogeneity in the disulfide bonds

Modelling Blood Flow and Metabolism in the Preclinical Neonatal Brain during and Following Hypoxic-Ischaemia

Hypoxia-ischaemia (HI) is a major cause of neonatal brain injury, often leading to long-term damage or death. In order to improve understanding and test new treatments, piglets are used as preclinical models for human neonates. We have extended an earlier computational model of piglet cerebral physiology for application to multimodal experimental data recorded during episodes of induced HI. The data include monitoring with near-infrared spectroscopy (NIRS) and magnetic resonance spectroscopy (MRS), and the model simulates the circulatory and metabolic processes that give rise to the measured signals. Model extensions include simulation of the carotid arterial occlusion used to induce HI, inclusion of cytoplasmic pH, and loss of metabolic function due to cell death. Model behaviour is compared to data from two piglets, one of which recovered following HI while the other did not. Behaviourally-important model parameters are identified via sensitivity analysis, and these are optimised to simulate the experimental data. For the non-recovering piglet, we investigate several state changes that might explain why some MRS and NIRS signals do not return to their baseline values following the HI insult. We discover that the model can explain this failure better when we include, among other factors such as mitochondrial uncoupling and poor cerebral blood flow restoration, the death of around 40% of the brain tissue. Copyright