Molecular and chemical characterization of genes involved in maize cuticular wax biosynthesis

The primary surfaces of the arial parts of plants, and the surfaces of reproductive organs are covered by an extra cellular layer called the cuticle. The cuticle provides the foremost protection to the plant in order to adapt to the terrestrial environment. The cuticle composed of a biopolymer (cutin), which is embedded in a coating of cuticular waxes. Understanding the biochemical, genetic and physiological mechanisms for the biosynthesis of these cuticular waxes is relatively poor. This body of work has established methods for the chemical analysis of the cuticular waxes of maize plants. I have used these methods to chemically characterize cuticular waxes and intermediates of cuticular wax biosynthesis in mutant plants that show aberrant accumulation of these components. In addition, I have generated a yeast-based heterologous expression system for testing the biochemical and genetic properties of genes that are involved in cuticular wax biosynthesis. These accomplishments have set the stage for deciphering the complexity of cuticular wax biosynthesis

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

PSR J0737-3039B: A probe of radio pulsar emission heights

In the double pulsar system PSR J0737-3039A/B the strong wind produced by pulsar A distorts the magnetosphere of pulsar B. The influence of these distortions on the orbital-dependent emission properties of pulsar B can be used to determine the location of the coherent radio emission generation region in the pulsar magnetosphere. Using a model of the wind-distorted magnetosphere of pulsar B and the well defined geometrical parameters of the system, we determine the minimum emission height to be ~ 20 neutron star radii in the two bright orbital longitude regions. We can determine the maximum emission height by accounting for the amount of deflection of the polar field line with respect to the magnetic axis using the analytical magnetic reconnection model of Dungey and the semi-empirical numerical model of Tsyganenko. Both of these models estimate the maximum emission height to be ~ 2500 neutron star radii. The minimum and maximum emission heights we calculate are consistent with those estimated for normal isolated pulsars.Comment: 29 pages, 14 figures, Accepted by ApJ on 3 March 201

Silencing Their Critics: How Government Restrictions against Civil Society Affect International ‘Naming and Shaming’

International ‘naming and shaming’ campaigns rely on domestic civil society organizations (CSOs) for information on local human rights conditions. To stop this flow of information, some governments restrict CSOs, for example by limiting their access to funding. Do such restrictions reduce international naming and shaming campaigns that rely on information from domestic CSOs? This article argues that on the one hand, restrictions may reduce CSOs’ ability and motives to monitor local abuses. On the other hand, these organizations may mobilize against restrictions and find new ways of delivering information on human rights violations to international publics. Using a cross-national dataset and in-depth evidence from Egypt, the study finds that low numbers of restrictions trigger shaming by international non-governmental organizations. Yet once governments impose multiple types of restrictions, it becomes harder for CSOs to adapt, resulting in fewer international shaming campaigns

A Survey on Simultaneous Wireless Information and Power Transfer

This paper presents a comprehensive study related to simultaneous wireless information and power transfer (SWIPT) in different types of wireless communication setups. Harvesting energy using SWIPT is an appealing solution in the context of extending battery life of wireless devices for a fully sustainable communication system. Strong signal power increases power transfer, but also causes more interference in information transfer, causing realization of the SWIPT challenging problem. This article provides an overview of technical evolution of SWIPT. A survey and qualitative comparison of the existing SWIPT schemes is provided to demonstrate their limitations in the current and 5G networks. Open challenges are emphasized and guidelines are provided to adapt the existing schemes in order to overcome these limitations and make them fit for integrating with the modern and emerging next generation communication networks, such as 5G systems

Isolation and Characterization of Plant growth-promoting Endophyticdiazotrophic Bacteria from Sri Lankan Rice Cultivars and Rapid Screening for their effect on Plant Growth Promotion

The present study was conducted to isolate and identify endophyticdiazotrophic bacteria in two Sri Lankan rice (Oryza Sativa L.) varieties; Suwandel and Bg 358 and to evaluate their potential to promote rice plant growth. A total of 15 putative endophyticdiazotrophic bacterial isolates were obtained from shoots and roots of Suwandel and Bg 358 rice varieties out of which 7 isolates were selected based on their ability to produce IAA and phosphate solubilization. According to the morphological characters and biochemical tests, these bacteria were identified belong to genera Bacillus (IN003, IN006, and IN007), Klebsiella (IN008 and IN018), Pantoea (IN009), and Enterobacter (IN015). All selected bacterial isolates produced IAA (7.1µmgl-1 to 30.9 µ mgl-1) in the tryptophan supplemented medium. Five out of seven bacterial isolates (IN006, IN007, IN008, IN015, and IN018) were able to solubilize inorganic phosphate on Pikovskaya\u27s agar medium. Rice seeds (Suwandel variety) treated with these endophyticdiazotrophic bacteria with plant growth-promoting ability showed significantly enhanced shoot length, root length, shoot fresh weight, shoot dry weight and root fresh weight compared to the uninoculated control. Plant inoculation experiment indicated that Enterobacter sp. (IN015) was most effective in rice plant growth promotion among seven bacterial isolates tested. These results strongly suggest that endophyticdiazotrophic bacteria characterized in this study could be successfully used to promote rice plant growth

DNA adducts in human urinary bladder and other tissues.

Tobacco smoking is associated with an increased risk of cancer in a number of organs, including bladder and lung. Tobacco smoke contains at least 50 known chemical carcinogens that exert their biological effects through their covalent binding to cellular DNA. Examining human DNA for the presence of altered nucleotides is a means of monitoring exposure to genotoxic chemicals. DNA isolated from 73 human bladder biopsies has been analyzed by 32P-postlabeling for the presence of aromatic/hydrophobic adducts. Butanol extraction of DNA digests resulted in up to a 3-fold greater recovery of adducts than nuclease P1 digestion. Among 16 nonsmokers, adduct levels were in the range 3.2-20.8/10(8) nucleotides (mean 9.7). Eight ex-smokers had values in the range 2.6-12.3 (mean 7.1). Thirteen smokers had adduct levels between 1.3 and 26.7 adducts/10(8) nucleotides (mean 9.5, not different from nonsmokers). Six cigar smokers had higher levels of adducts (mean 12.1, range 7.3-15.0), but pipe smokers did not (five samples, mean 8.6, range 2.9-12.7). A further 8 samples from nonsmokers and 17 from smokers were examined in more detail. Although most of the DNA binding appears not to be smoking related, the levels of one adduct were found to be on average 2-fold higher in smokers (p < 0.005, one-tailed t test). Studies on tissues of the respiratory tract demonstrate a correlation between DNA adduct levels and exposure to tobacco smoke. Evidence to date on the influence of smoking on adducts in peripheral blood cells is equivocal; some studies demonstrate a significant effect, whereas others do not.(ABSTRACT TRUNCATED AT 250 WORDS

Rhodium amine complexes tethered on silica supported gold-palladium bimetal catalysts for arene hydrogenation

Our group has previously developed a new type of catalyst by combining the advantages of homogeneous, and heterogeneous catalysts. This has been prepared by tethering a transition metal complex on to a supported metal catalyst such as Pd-Si02. Later work demonstrated those new TCSM catalysts as highly active catalysts for arene hydrogenation and hydroformylation reactions. This thesis describes a project completed which complement the initial findings of this group. Catalytic activities for hydrogenation of arenes under the mild conditions of 400C and 1 atm H2 pressure, have been investigated using the catalyst prepared by tethering Rh(COD)[H2NCH2CH2NHSi(CH2)3Si(OCH3)3](X)on the silica support of the bimetal catalyst Au:Pd-Si02. Different TCSM catalysts have been prepared by simply changing its counter anion; X = Cl,̄ I,̄ PF6,̄BPh4,̄CF3so3.̄ It has been shown that PF6-Rh(COD)N2/Au:Pd-SiO2 catalyst as the most active catalyst for arene hydrogenation. The rates of toluene hydrogenation as a function of the anion for X-Rh(COD)N2/Pd-Si02 catalysts have also been investigated. The catalyst BPh4-Rh(COD)N2/Pd-Si02 showed higher activity in that series. In general, the most weakly coordinating anions, PF6- and BPh4-, gave the most active catalysts. Studies carried out to investigate the effect of two metals on the catalytic activity shows that the activities of catalysts with added Au are less active only by factor of two. The rates of toluene hydrogenation with constant Au loading (4.2 wt%) appear to increase linearly with Pd amount increase from 1.0 wt% up to 9.8 wt%. These TCSM catalysts (X-Rh(COD)N2/Au:Pd-Si02) were complicated by variations in the amounts of the X-Rh(COD)N2 complex that was tethered to the Au:Pd-SiO2 catalysts. It appears that both the amounts of tethered complex i.e., Rh % and the amount of Au and Pd influences strongly on the activation of these TCSM catalysts. Although, the mechanism for the function of TCSM (tethered complex on supported metal catalysts) is not known, it could involve with the dissociative adsorption of H2 on supported Pd

Updates on the Morphometric Characterization of Indian Pangolin (Manis crassicaudata) in Sri Lanka

An accurate morphological description and analysis based on reliable data are unavailable for the geographically isolated population of M. crassicaudata in Sri Lanka. This study provides the most updated morphological description of M. crassicaudata with special reference to body measurements directly obtained from 27 specimens collected island-wide. Morphological parameters were recorded under three age classes that were defined based on their body weight (BW) and total body length (TBL); juvenile (BW: 7.3 kg TBL: >101 cm) and gender to reveal sexual dimorphism based on morphometric parameters. The TBL of adult males ranged between 137 and 177 cm while body weight ranged between 20.4 and 48.8 kg. The average count of body scales was 511 ± 21. The body scales were found arranged in 13 longitudinal rows with the highest number of scales observed on the vertebral scale row (16 ± 1). Three major scale morphs were identified; broad rhombic scales, elongated kite-shaped scales, and folded shaped scales. Broad rhombic shaped scales was the dominant scale type (80.49%) on the body (405 ± 7). The tail-length to body-length ratio of an Indian pangolin was 0.87. The tail length of an Indian pangolin is a reliable predictor of the TBL and has potential implications in quick field data gathering

Investigation of volcanic ash based geopolymers as potential building materials

Volcanic ash powders from Etna (Italy) and Cameroon were used as the principal source of aluminosilicate to produce geopolymers with the potential for making building products. The volcanic ash was ball milled and reacted with concentrated alkaline solutions for polymerisation and subsequent curing at 75-400 °C for 12-48 h. It was found that the gel was more viscous than a similar gel formed from metakaolin. Geopolymers made from both ashes had bulk densities of 1.7-2.0 g/cm3 and water absorption values of 20-25 %. Their compressive strength values were 25-35 MPa and the bi-axial four-point flexura! strength values ranged from 14-20 MPa. These values increased by 20 % when cured for 21 d after 90 d storage. It was also found that by curing at 200-400 °C the mechanical properties increased. Scanning electron micrographs showed that with thermal curing microcrystalline phases were present along with undissolved crystalline phases. These phases remained bound to the matrix and acted as a filler for strengthening the materials. The Ca, Mg and Fe present as impurities in the volcanic ash formed some of these crystalline phases and did not form any deleterious hydroxide or carbonate phases