165 research outputs found
Immunomodulatory Activity of the Marine Sponge, Haliclona (Soestella) sp. (Haplosclerida: Chalinidae), from Sri Lanka in Wistar Albino Rats: Immunosuppression and Th1-Skewed Cytokine Response
No full textNatural secondary metabolites of sponges of the genus Haliclona are associated with an array of biological activity with therapeutic usage. We investigated the immunopharmacological properties of a presumably novel marine sponge species from Sri Lanka, Haliclona (Soestella) sp. Sponge material was collected from southern Sri Lanka by scuba diving. Sponge identification was based on spicule and skeleton morphology using light microscopy. Selected in vivo and ex vivo tests investigated nonfunctional and functional immunomodulatory activity of the Haliclona (Soestella) sp. crude extract (HSCE) in the Wistar rat model. Compared to the controls, rats orally gavaged daily for 14 consecutive days with 15 mg/kg dose of the HSCE manifested a significant reduction of immune cell counts of total WBCs (by 17%; p<0.01), lymphocytes (38%), platelets (52%), splenocytes (20%), and bone marrow cells (BMC; 60%) (p<0.001), with a concurrent increase in the neutrophil : lymphocyte ratio (p<0.05); RBC counts abated by 53% (p<0.001). A significant reduction of the splenosomatic index was evident with the 10 and 15 mg/kg doses (p<0.001). Rat plasma TNF-α cytokine level was augmented by tenfold (p<0.001), IL-6 level by twofold (p<0.01) with the 15 mg/kg HSCE treatment, while IL-10 was detectable in rat plasma only with this treatment; the corresponding Th1 : Th2 cytokine ratio (TNF-α : IL-10) was indicative of an unequivocal Th1-skewed cytokine response (p<0.01). Ex vivo bone marrow cell and splenocyte proliferation were significantly and dose dependently impaired by HSCE (IC50 0.719 and 0.931 μg/mL, respectively; p<0.05). Subacute toxicity testing established that HSCE was devoid of general toxic, hepatotoxic, and nephrotoxic effects. In conclusion, HSCE was orally active, nontoxic, and effectively suppressed nonfunctional and functional immunological parameters of Wistar rats, suggestive of the potential use of the HSCE as an immunosuppressant drug lead
Evaluation of in vitro anti-inflammatory activity of five selected marine sponges against denaturation of protein-A pilot study
No full textBackground: Marine sponges are well renowned for producing bioactive secondary metabolites with drug leads. Screening of anti-inflammatory compounds from marine sponges is highly appreciated in the field of marine pharmacognosy due to their effectiveness and specificity over the most of synthetic non-steroidal anti-inflammatory drugs. In vitro models to test anti-inflammatory activity are considered obligatory prior to pre-clinical studies.
Objective: To evaluate in vitro anti-inflammatory effect of crude extracts of five marine sponge samples (N=5), collected from Dehiwala, Colombo, Sri Lanka.
Methodology: Identification of sponge species were based on morphology, spicule and skeleton analysis, using light microscopy. Each sponge crude extract (SCE) was tested for selected zoo- chemicals and against the denaturation of albumin to assess the anti-inflammatory activity. Diclofenac sodium was used as the reference drug.
Results: Sponge samples were identified as 1) Stylissa sp, 2) Stylissa carteri, 3) Axinella sp., 4) Phakellia sp. and 5) Family Axinellidae. Zoo-chemical analysis indicated the presence of alkaloids, saponins, terpenoids, and sterols in sponge extracts in varying degree. Heat induced egg albumin denaturation was inhibited by 4 SCEs specifying marked anti-inflammatory activity. Accordingly, the 3 sponge crude extracts were more potent (IC50 = 22.74 for Sp. 02, 3.98 for Sp. 03 and 63.665μgmL -1for Sp. 05) than the of standard reference drug, Diclofinac sodium (IC50=147.02 μg/mL). Conclusions: Thus, the present study for the first time investigated in vitro anti-inflammatory activity of crude extract of 5 selected marine sponge species from Sri Lanka, out of which 3 were more potent than the reference diclofenac sodium. Therefore, isolation and characterization of bioactive compounds which are responsible for anti- inflammatory activity will lead to discover novel marine derived anti-inflammatory drugs in the future
Waste biomass substrates as feed stock option for microbial fuel cell and scaling up factors
No full textThe waste biomass substrates for microbial fuel cell (MFC) were tested using a batch
type MFC. The performances of each cell were measured individually by recording
the Open Circuit Voltage (OCV) against time using three different substrates; cow
dung, coconut water and glucose. The cell was operated using an aerated cathode for
waste substrates. A chemical cathode was used for defined substrate. The
relationship for the voltage generation with the nutrients (in terms of Chemical
Oxygen Demand (COD)) and the availability of electricigens was discussed for both
defined and waste substrates. The highest of the average of mean OCV was observed
for glucose (0.35V) and for waste substrates it varied from 0.18V to 0.28V. Coconut
water had a higher COD compared to cow dung even though the availability of the
electricigens was unknown.
Each step in electricity generation in MFC was studied and the parameters which
affected power generation were identified. Dimensional analysis was done to the
selected parameters using the “Buckingham Pie” theorem and a set of dimensionless
groups was calculated. The physical meaning behind each of the dimensionless
groups was analysed. Using the dimensionless groups, a polynomial equation was
developed as follows:
Da = α (μ/ρ)a (d3gρ2/μ2)b (h/d)c
Where, D is the mass diffusivity (m2s-1),μ viscosity (kgm-1s-1),ρ density (kgm-3) ,d
distance between the two electrodes (m), h height of the electrode (m), g
gravitational constant (ms-2) and α, a, b, c are constants.
This equation is useful in finding the relationship between the operational parameters
when the MFC is operating at its highest power density with no forced convection of
the electrolyte. Using a set of experiments, the values of the constants can be found,
with those values the equation is important in the process of scaling up of the
microbial fuel cell
Rhizobiophage Functional Genomics
No full textRhizobiophages are bacterial viruses that specifically infect nitrogen-fixing, legume-nodulating bacterial group rhizobia. In this study, the whole genome sequences of eight rhizobiophages were generated. These included four Rhizobium leguminosarum myophages (AF3, P9VFCI, RL2RES and RL38JI), two R. leguminosarum siphophages (P11VFA and B1VFA), one R. leguminosarum phage with unknown morphology (V1VFA-S) and one M. japonicum phage (Cp1R7A-A1). Characterization of Cp1R7A-A1 indicated a siphophage morphology with a prolate capsid, a distinct genome, and a close phylogenetic relationship to certain Caulobacter siphophages with similar morphology. The myophages AF3, P9VFCI, RL2RES and RL38JI belong in the ICTV family Ackermanviridae and in a T4-like group of viruses. A recombination dependent replication mechanism and circularly permuted genomes due to a pure headful packaging mechanism were postulated for these phages. B1VFA and V1VFA-S had genomes similar to each other. A theta replication mechanism and phage genome terimini with direct terminal repeats were suggested for these two. P11VFA was similar to the R. leguminosarum phage L338C genome available in databases. Quantitative reverse transcription PCR for selected genes of phages Cp1R7A-A1 and Lo5R7ANS, using RNA extracts from Mesorhizobium japonicum separately infected with these phages, confirmed an early-late type maximum gene expression in Lo5R7ANS. Selected replication genes showed a maximum expression 30 minutes after infection, but structural and packaging gene expression maximized after 90 minutes. Discrete timepoints of maximum expression for any selected gene in Cp1R7A-A1 were not observed during the given incubation periods, probably due to the slow rate of replication and assembly. RNAseq analysis of Cp1R7A-A1 infected M. japonicum indicated the expression of all 237 putative phage genes and gave some insights into host gene expression during phage infection. Attempts were made to engineer R. leguminosarum and M. japonicum to carry a plasmid with a functional CRISPR/Cas9 system. A CRISPR/Cas9 system derived from Streptococcus pyogenes was cloned into the broad-host range vector pRK415. The new vector pRK415Cas9 functioned successfully in E. coli. However, it was not functional in Rhizobium or Mesorhizobium species. Cas9 promoter expression studies and RT-PCR revealed that the Cas9 promoter was expressed in Mesorhizobium. However, whether correct translation occurs has yet to be tested
Integrating Indicators in Agricultural Vulnerability Assessment to Climate Change
No full textAbstract
Climate change stands as one of the most pressing challenges confronting global ecosystems and human livelihoods. The agriculture sector of Anuradhapura district, Sri Lanka, well renowned for its pivotal role in the nation’s food production, faces an increasing threat from the changing climate. This study aims to incorporate the indicator system method which uses a set of indicators to assess the agricultural vulnerability (AV) to climate change in Anuradhapura district. The AV assessment used in this study involves three principal components exposure, sensitivity, and adaptive capacity. The indicators are normalized to allow spatial analysis and smooth integration within a geographic information system (GIS) framework. The AV of Anuradhapura district ranged from 0.32 to 0.67 and was divided among five levels very low, low, moderate, high, and very high. The findings suggest that Anuradhapura’s agricultural sector was significantly impacted by climate change as the majority of the total area was found to have very high, high, and moderate levels of AV with 25, 28, and 24%, respectively. The results obtained from this study are essential for formulating plans to improve Anuradhapura’s agricultural sector resilience and adaptability to ensure food security and livelihood sustainability considering the ever-changing climate.Abstract
Climate change stands as one of the most pressing challenges confronting global ecosystems and human livelihoods. The agriculture sector of Anuradhapura district, Sri Lanka, well renowned for its pivotal role in the nation’s food production, faces an increasing threat from the changing climate. This study aims to incorporate the indicator system method which uses a set of indicators to assess the agricultural vulnerability (AV) to climate change in Anuradhapura district. The AV assessment used in this study involves three principal components exposure, sensitivity, and adaptive capacity. The indicators are normalized to allow spatial analysis and smooth integration within a geographic information system (GIS) framework. The AV of Anuradhapura district ranged from 0.32 to 0.67 and was divided among five levels very low, low, moderate, high, and very high. The findings suggest that Anuradhapura’s agricultural sector was significantly impacted by climate change as the majority of the total area was found to have very high, high, and moderate levels of AV with 25, 28, and 24%, respectively. The results obtained from this study are essential for formulating plans to improve Anuradhapura’s agricultural sector resilience and adaptability to ensure food security and livelihood sustainability considering the ever-changing climate
Microbial Fuel Cell (MFC) Technology and Scale up Factors in a Sri Lankan Context
No full textMFC systems are generally robust systems that can operate on variable feedstock and are usually capable of oxidizing
the organic substrates completely to carbon dioxide and water. This paper discuss about scaling up factors of the M F C
addressing each and every major component of the cell. Experimental results on lab scale M F C using cow dung have
included and recent advances in this technology along with current uses and other potential applications are also
identified in this pape
Buddhist Advice for the Development of Student Life
No full textThe students should be disciplined, also students who have knowledge, skills, attitudes and disciplines are essential for a good society. The emergence of a group of students armed with knowledge, attitudes and values will be able to successfully face those challenges in the contemporary socio, economic, political, and cultural crisis in society. The Buddha can be considered as the absolute teacher of the world and his disciples are the ideal form of students. Research Problem highlights What are the Buddhist advice for the development of students’ life? The Objective of the Research is to examine the Buddhist advice to life and study the way how to apply those teachings for students’ life. Research Methodology is based on the primary texts written on which related to the Buddhist advice for development of student life. Books, journals, articles, related literary, cultural, and philosophical sources were referred to as secondary sources
Flow alterations due a constructed reservoir in the Menik Ganga basin, Sri Lanka
No full textAbstract
Natural water flows and their ecosystems are altered due to manmade hydraulic structures like dams. However, limited research on hydrologic alteration has been carried out in developing countries. This research explores the hydrologic alterations which occurred in the Menik Ganga basin, Sri Lanka due to the Weheragala reservoir constructed in 2009 for inter basin transfer. The hydrologic variations of the flow regime due to the construction of the reservoir was analyzed using Indicators of Hydrologic Alterations (IHA). For this purpose, we compared the calculated IHAs for streamflow at the Kataragama station (located downstream of Weheragala) during pre-construction (1990–2009) and post construction (2010–2019) periods. Also, the IHAs of simulated flows from the Water Evaluation And Planning (WEAP) model during 2010–2019 was compared with observed gauge discharge during the same period. The monthly observed flows in the “Maha” rainfall season (September to March) demonstrated a decreasing trend in post dam period with respect to pre dam period (highest decrease of 77 m3/s during October), whilst it showed an increasing trend (highest increase of 5 m3/s during August) in the Yala season (May to August) in the post-reservoir construction scenario. This was further visualized by comparing the indicators of the simulated flows with observed for post reservoir period, in which highest percentage differences occurred in June (− 4000% in 2016) and November (− 300% in 2010) for Yala and Maha periods respectively. Large alterations of the river flow due to the impoundment depicted by higher percentage differences. These alterations are extensively examined by other indicators as well. The fluctuations of flows have been decreased due to the construction of the reservoir which resulted in reductions of low and high pulses. The results are highly appealing to the authorities who are in water resources management to reach sustainable goals.Abstract
Natural water flows and their ecosystems are altered due to manmade hydraulic structures like dams. However, limited research on hydrologic alteration has been carried out in developing countries. This research explores the hydrologic alterations which occurred in the Menik Ganga basin, Sri Lanka due to the Weheragala reservoir constructed in 2009 for inter basin transfer. The hydrologic variations of the flow regime due to the construction of the reservoir was analyzed using Indicators of Hydrologic Alterations (IHA). For this purpose, we compared the calculated IHAs for streamflow at the Kataragama station (located downstream of Weheragala) during pre-construction (1990–2009) and post construction (2010–2019) periods. Also, the IHAs of simulated flows from the Water Evaluation And Planning (WEAP) model during 2010–2019 was compared with observed gauge discharge during the same period. The monthly observed flows in the “Maha” rainfall season (September to March) demonstrated a decreasing trend in post dam period with respect to pre dam period (highest decrease of 77 m3/s during October), whilst it showed an increasing trend (highest increase of 5 m3/s during August) in the Yala season (May to August) in the post-reservoir construction scenario. This was further visualized by comparing the indicators of the simulated flows with observed for post reservoir period, in which highest percentage differences occurred in June (− 4000% in 2016) and November (− 300% in 2010) for Yala and Maha periods respectively. Large alterations of the river flow due to the impoundment depicted by higher percentage differences. These alterations are extensively examined by other indicators as well. The fluctuations of flows have been decreased due to the construction of the reservoir which resulted in reductions of low and high pulses. The results are highly appealing to the authorities who are in water resources management to reach sustainable goals
Qualitative mineralogical analysis of Barracuda exploration well in the offshore Mannar Basin (the Indian Ocean) using FTIR and XRD techniques
No full textThe Mannar Basin plays a vital role in petroleum exploration in Sri Lanka, and its Barracuda exploration well was drilled up to 4206 m in depth. The objective of the current study is to identify mineralogy using Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) analyses. The FTIR and XRD analyses confirm the presence of quartz, feldspar, clay minerals (e.g., kaolinite, montmorillonite), calcite, and hematite in all marlstone and mudstone samples. These sedimentary rocks can be identified as potential petroleum source rocks in the Mannar Basin. Quartz, carbonate, and hematite cementations are directly reduced porosity and permeability, and thus primary migration of hydrocarbons from potential source rocks. Clay minerals act as a seal for hydrocarbon migrations in the Mannar Basin. A variety of dominant clay mineral assemblages allows the reconstruction of several paleoclimatic chronozones in warm/wet and arid climates. In contrast, feldspar dissolution promotes the primary migration of hydrocarbon from potential petroleum source rocks. Consequently, this study concluded that common minerals such as quartz, carbonate, and hematite are associated with the trapping and binding processes of hydrocarbons
Mild Hydrothermal Treatment for Improving Outturn of Basmati Rice
No full textHydrothermal treatment of rice, called “Parboiling”, is an ancient traditional process in Asian countries. It consists of soaking rough rice in water and steaming it, and it both reduces the level of grain breakage and increases head yield of rice during milling. However, parboiling of rice is associated with some drawbacks regarding consumer preferences: the loss of its aroma, reduced rice-kernel whiteness and increased kernel hardness. This research study was carried out to develop a mild hydrothermal treatment that could be applied to basmati paddy by controlling hydrothermal treatment, i.e., soaking water temperature, steaming pressure and time. The Basmati 370 paddy variety was used for this study. The results revealed that, by soaking the paddy in hot water (70 ± 2 °C) for 75 min and steaming the soaked paddy for 20 min with non-pressurized steam at atmospheric pressure, and soaking the paddy for 120 min in hot water (70 ± 2 °C) and steaming the soaked paddy for 4 min with pressurized steam (4 kg/cm2), the optimum treatments are achieved. These optimum hydrothermal treatments were able to produce high head rice yield and preserve the basmati aroma, colour, hardness and palatability characteristics similar to non-parboiled basmati rice. Further, nutritional values such as vitamin B and protein content were also significantly preserved by these mild hydrothermal treatments. These optimized treatment combinations achieved minimized grain breakage while increasing head rice yield during milling and, at the same time, preserved basmati aroma, kernel whiteness, cooking and palatability characteristics similar to non-parboiled rice
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