Identifying the impact of tidal level variation on river basin flooding

Different parts of Sri Lanka are regularly subjected to a wide range of natural disasters, of which floods are most common. When severe, flooding can decrease the economic and social development of the country and the Government of Sri Lanka has to spend huge amounts of money each year to address such problems. Floods occur mostly because of heavy rainfall combined with human-induced factors in the catchment areas. In this project, tidal level variation is considered as a factor for floods in the river basins. The tidal level changes periodically due to the gravitational attraction from the sun and the moon and the centrifugal force of the earth’s rotation. This project studied the relationship between changes in tide and river water level in the mouth of the Kelani River. Tidal data was collected from the Colombo Harbor, and water level data and river flow data was obtained from the Nagalagam Street gauge and Hanwella gauge. It was found that there is a direct relationship between tidal level and flood level in the river mouth area. Therefore, it is proposed that tidal level variations be considered in order to make accurate flood predictions in the river mouth areas.Length: pp.119-126River basinsFlooding

Localisation of autosomal genes in man using chromosomal aberrations

No abstract available

A resorcinarene for inhibition of Aβ fibrillation.

Amyloid-β peptides (Aβ) fibrillation is the hallmark of Alzheimer's disease (AD). However, it has been challenging to discover potent agents in order to inhibit Aβ fibrillation. Herein, we demonstrated the effect of resorcinarene on inhibiting Aβ fibrillation in vitro via experimental and computational methods. Aβ were incubated with different concentrations of resorcinarene so as to monitor the kinetics by using thioflavin T binding assay. The results, which were further confirmed by far-UV CD spectroscopy and atomic force microscopy, strongly indicated that the higher concentration of resorcinarene, the more effective the inhibition of Aβ fibrillation. A cytotoxicity study showed that when sea urchin embryos were exposed to the resorcinarene, the majority survived due to the resorcinarene low toxicity. In addition, when the resorcinarene was added, the formation of toxic Aβ 42 species was delayed. Computational studies of Aβ fibrillation, including docking simulations and MD simulations, illustrated that the interaction between inhibitor resorcinarene and Aβ is driven by the non-polar interactions. These studies display a novel strategy for the exploration of promising antiamyloiddogenic agents for AD treatments

Strabismus-mediated primary archenteron invagination is uncoupled from Wnt/β-catenin-dependent endoderm cell fate specification in Nematostella vectensis (Anthozoa, Cnidaria): Implications for the evolution of gastrulation

<p>Abstract</p> <p>Background</p> <p>Gastrulation is a uniquely metazoan character, and its genesis was arguably the key step that enabled the remarkable diversification within this clade. The process of gastrulation involves two tightly coupled events during embryogenesis of most metazoans. Morphogenesis produces a distinct internal epithelial layer in the embryo, and this epithelium becomes segregated as an endoderm/endomesodermal germ layer through the activation of a specific gene regulatory program. The developmental mechanisms that induced archenteron formation and led to the segregation of germ layers during metazoan evolution are unknown. But an increased understanding of development in early diverging taxa at the base of the metazoan tree may provide insights into the origins of these developmental mechanisms.</p> <p>Results</p> <p>In the anthozoan cnidarian <it>Nematostella vectensis</it>, initial archenteron formation begins with bottle cell-induced buckling of the blastula epithelium at the animal pole. Here, we show that bottle cell formation and initial gut invagination in <it>Nematostella </it>requires NvStrabismus (NvStbm), a maternally-expressed core component of the Wnt/Planar Cell Polarity (PCP) pathway. The NvStbm protein is localized to the animal pole of the zygote, remains asymmetrically expressed through the cleavage stages, and becomes restricted to the apical side of invaginating bottle cells at the blastopore. Antisense morpholino-mediated NvStbm-knockdown blocks bottle cell formation and initial archenteron invagination, but it has no effect on Wnt/ß-catenin signaling-mediated endoderm cell fate specification. Conversely, selectively blocking Wnt/ß-catenin signaling inhibits endoderm cell fate specification but does not affect bottle cell formation and initial archenteron invagination.</p> <p>Conclusions</p> <p>Our results demonstrate that Wnt/PCP-mediated initial archenteron invagination can be uncoupled from Wnt/ß-catenin-mediated endoderm cell fate specification in <it>Nematostella</it>, and provides evidence that these two processes could have evolved independently during metazoan evolution. We propose a two-step model for the evolution of an archenteron and the evolution of endodermal germ layer segregation. Asymmetric accumulation and activation of Wnt/PCP components at the animal pole of the last common ancestor to the eumetazoa may have induced the cell shape changes that led to the initial formation of an archenteron. Activation of Wnt/ß-catenin signaling at the animal pole may have led to the activation of a gene regulatory network that specified an endodermal cell fate in the archenteron.</p

Towards using ICT to Enhance Flow of Information to aid Farmer Sustainability in Sri Lanka

Farmers need information at all stages of the farming life cycle to make optimal decisions. The required information includes not only prior knowledge but also real time (dynamic) information such as market prices and current production levels. Some valuable information needed by the farmers is produced by government organizations and is available in different locations in different formats. Although farmer is the most important stakeholder in agriculture, there has not been much effort to provide the essential information to farmers on a real time basis. This lack of information is creating many difficulties for farmers as they are not being able to make the correct decisions relating to their farming activities. Through field studies we have identified information required by farmers at various stages of the farming cycle and official sources where this information is available. Next we developed an information flow model that connects various information sources to farmers’ information needs. Based on these findings we are now developing a mobile phone based information system to deliver the required information to farmers in real time

Towards An Agriculture Information Ecosystem

Stakeholders of a domain in their day today activities generate information which is a valuable resource. To obtain full value of this information it should reach right people at the right time. To investigate how this can be achieved we developed an information flow model for agriculture domain by mapping information needed by stakeholders to information generated by others using set of aggregation and disaggregation operators. We found majority of information needs of stakeholders can be fulfilled by applying these operators to information produced by some other stakeholders thus creating a direct benefit to encourage sharing information. This information flow model had many similarities to biological ecosystems where nutrient cycles and energy flows are replaced by information flows. Based on this information ecosystem model we are developing a mobile based information system for farmers in Sri Lanka. Like biological ecosystems information ecosystems will also need time to grow and become sustainable

Studies in Protein Metabolism: The Inter-Relationships of Energy Metabolism and Protein Metabolism

Part I: The relationship between energy intake and nitrogen balance. 1. Experiments are described in which additional carbohydrate (glucose) and additional fat (olive oil) were given to adult rats already receiving an adequate diet. This caused a reduction in urinary N output whether the surfeit was given with dietary protein or 5 to 12 hours apart from the protein. N retentions of similar magnitude were obtained whether the surfeit was given in the form of carbohydrate or an isodynamic amount of fat. 2. Similar experiments were carried out on adult dogs, the additional carbohydrate (sucrose) being given with the protein on one single occasion, and 7 and 12 hours apart from the protein on other single occasions. Nitrogen retention was obtained when sucrose was given within 7 hours of the protein meal. Repeated daily doses of sucrose 12 hours after the protein meal eventually produced a retention of N of equal magnitude to the amount stored when sucrose was given with the protein. 3. Experiments were also carried out on 4 human subjects receiving adequate diets. Additional carbohydrate (sucrose) reduced the urinary N output whether it was taken with the diet or 5 1/2 hours after the last meal of the day. When the sucrose was taken apart from the meals, a lag period of 24 to 48 hours was observed before the urinary N output was reduced. 4. It has been concluded that carbohydrate and fat act interchangeably as energy sources in sparing protein; they do not need to be taken along with dietary protein to exert this sparing action. This N sparing effect is probably produced by increasing the tissue concentration of some energy-yielding metabolite which is necessary for the synthesis of protein. Part II: The effect of energy intake on the metabolism of adenosine triphosphate in the liver. 1. Experiments are described in which energy in the form of olive oil was given to rats receiving a fixed basal diet. This caused a significant change in the ATP/ADP ratio, which increased linearly with the amount of energy added. 2. The significance of the ATP/ADP ratio is discussed, and it has been concluded that energy intake influences protein synthesis by affecting the "phosphate potential". Part III: The influence of energy intake on the metabolism of ribonucleoproteins. 1. A study has been made of the effect of variations in energy intake on the amount of ribonucleic acid (RNA) in the rat liver, and on the uptake of labelled phosphorus by RNA. 2. When the diet contained protein, addition of energy in the form of carbohydrate or fat resulted in a considerable increase In the amount of RNA per liver: when the diet lacked protein, an increase in energy intake caused only a slight change in the amount of RNA. 3. The uptake of by RNA, as measured by relative specific activity, behaved in the opposite way. Uptake was not affected by variations In energy intake when the diet contained protein, but it was considerably stimulated by addition of energy to the protein-free diet. 4. These results indicate that the absolute rate of incorporation of phosphorus into RNA is dependent on energy intake. At each level of protein intake, addition of energy increases the total number of P atoms incorporated into RNA, in one case by an increase in the amount of RNA per liver without a change in the percentage of P atoms Incorporated in a given time, in the other case by an increase in the incorporation rate to compensate for the much smaller change in the amount of RNA per liver. Part IV: The effect of energy intake on the metabolism of liver phospholipid. 1. Experiments similar to those described in Part III were carried out on rats, to study the effect of variations in energy intake on the amount of phospholipid per liver, and on the uptake of labelled phosphorus by the liver phospholipid. 2. On a protein-containing diet, addition of energy (carbohydrate) produced a marked increase in the amount of phospholipid per liver; when the diet was protein-free, the phospholipid per liver decreased slightly with the addition of energy. 3. The uptake of 32P, as measured by the relative specific activity, was increased by addition of energy, whether the diet contained protein or not, the change being greater in the latter case. 4. The absolute rate of Incorporation of phosphorus was greater on a protein-containing diet, the increase in the relative specific activity on a protein-free diet being balanced by a drop in the total quantity of phospholipid per liver. It has been concluded that the liver phospholipid differs from RNA in that the absolute rate of incorporation of phosphorus is affected by the level of protein intake as well as by the intake of energy. (Abstract shortened by ProQuest.)

Is "not just right experience" (NJRE) in obsessive-compulsive disorder part of an autistic phenotype?

OBJECTIVE: Harm avoidance (HA) and "not just right experience" (NJRE) have been proposed to be 2 core motivational processes underlying obsessive-compulsive disorder (OCD). The objective of this study was to explore whether NJRE demarcates a neurodevelopmental OCD subgroup distinct from HA related to autistic traits and/or to a broader phenotype of cognitive rigidity and sensory processing difficulties associated with an earlier age of OCD onset. METHODS: A correlational design investigated whether NJRE and HA are distinct entities in OCD and explored their relationship to autism spectrum disorder (ASD) traits measured by the Autism Quotient (AQ), sensory processing, set-shifting, and age of OCD onset in an OCD sample (N=25). RESULTS: NJRE was only moderately (r=.34) correlated to HA and not significant in this study. Consistent with predictions, NJRE was associated with sensory processing difficulties and an earlier age of OCD onset. No significant relationships were found between NJRE and ASD traits as measured by the AQ or set-shifting difficulties. CONCLUSIONS: These preliminary findings suggest a lack of evidence demonstrating NJRE as a manifestation of core autistic traits as measured by the AQ. However, NJRE was associated with sensory abnormalities and an earlier age of OCD onset. The role of NJRE as a developmental, and possibly neurodevelopmental, risk factor for OCD possibly warrants further investigation

Transfer of a large gene regulatory apparatus to a new developmental address in echinoid evolution

Of the five echinoderm classes, only the modern sea urchins (euechinoids) generate a precociously specified embryonic micromere lineage that ingresses before gastrulation and then secretes the biomineral embryonic skeleton. The gene regulatory network (GRN) underlying the specification and differentiation of this lineage is now known. Many of the same differentiation genes as are used in the biomineralization of the embryo skeleton are also used to make the similar biomineral of the spines and test plates of the adult body. Here, we determine the components of the regulatory state upstream of these differentiation genes that are shared between embryonic and adult skeletogenesis. An abrupt “break point” in the micromere GRN is thus revealed, on one side of which most of the regulatory genes are used in both, and on the other side of which the regulatory apparatus is entirely micromere-specific. This reveals the specific linkages of the micromere GRN forged in the evolutionary process by which the skeletogenic gene batteries were caused to be activated in the embryonic micromere lineage. We also show, by comparison with adult skeletogenesis in the sea star, a distant echinoderm outgroup, that the regulatory apparatus responsible for driving the skeletogenic differentiation gene batteries is an ancient pleisiomorphic aspect of the echinoderm-specific regulatory heritage

Electrical control and enhancement of dropwise condensation

Condensation of vapor typically occurs via the formation of condensate films on condensing surfaces; however, the liquid film imposes a substantial thermal resistance to heat transfer. Filmwise condensation heat transfer can be enhanced by 5-7X by condensing vapor as droplets, which roll-off the surface, thereby preventing buildup of a liquid film. Dropwise condensation heat transfer can be enhanced by the use of electrowetting (EW) to enhance coalescence, growth and shedding of condensed droplets. This dissertation includes several fundamental studies on EW-enhanced dropwise condensation. Experiments, analytical modeling and statistical modeling are used to gain a deeper understanding of droplet growth, coalescence and shedding under EW. Chapter 1 details the motivation for this study and the objectives of this dissertation. Chapter 2 includes a literature review of condensation, electrowetting and data science- based statistical methods. Chapter 3 presents a detailed experimental study of dropwise condensation of humid air under the influence of electrowetting fields. An analytical heat transfer model, which accounts for the presence of non-condensable gases, is used to predict the heat transfer benefits associated with electrowetting-assisted condensation. Chapter 4 presents a detailed analysis of electrowetting-induced coalescence dynamics of a distribution of water droplets. Statistical modeling-based algorithms are used to identify key electrowetting-related parameters that influence droplet coalescence; the influence of these parameters on coalescence is quantified. Chapter 5 studies droplet shedding dynamics under electrowetting and shows that an intermittent electric field can significantly increase condensation rates (as compared to a continuous electric field). A key finding is the almost complete removal of water from surfaces in very short durations (< 1 sec) is observed. It is also found that the extent and rate of water removal depends on the applied voltage and frequency of the AC EW waveform, respectively. Chapter 6 presents a novel approach and an experimentally validated model to analyze the oscillations of water droplets under the influence of AC electrowetting. Chapter 7 summarizes key conclusions and outlines suggestions for future work. Overall, the research reported in this dissertation has led to fundamental contributions in the areas of condensation and microfluidics. This multidisciplinary work has involved experiments, analytical modeling and statistical modeling. Results show that electrowetting fields influence all the phenomena important in dropwise condensation (growth, coalescence, shedding of droplets). Electrowetting is therefore a powerful tool to control and enhance condensation heat transfer. This research impacts applications in energy (steam condensation, refrigeration), water (atmospheric water harvesting, desalination) and infrastructure (self-cleaning).Mechanical Engineerin