Incidental effects of automated retweeting: an exploratory network perspective on bot activity during Sri Lanka’s presidential election in 2015

The role of automated or semiautomated social media accounts, commonly known as “bots,” in social and political processes has gained significant scholarly attention. The current body of research discusses how bots can be designed to achieve specific purposes as well as instances of unexpected negative outcomes of such use. We suggest that the interplay between social media affordances and user practices can result in incidental effects from automated agents. We examined a Twitter network data set with 1,782 nodes and 5,640 edges to demonstrate the engagement and outreach of a retweeting bot called Siripalabot that was popular among Sri Lankan Twitter users. The bot served the simple function of retweeting tweets with hashtags #SriLanka and #lk to its follower network. However, the co-use of #Sri Lanka and/or #lk with #PresPollSL, a hashtag used to discuss politics related to Sri Lanka’s presidential election in 2015, resulted in the bot incidentally amplifying the political voice of less engaged actors. The analysis demonstrated that the bot dominated the network in terms of engagement (out-degree) and the ability to connect distant clusters of actors (betweenness centrality) while more traditional actors, such as the main election candidates and news accounts, indicated more prestige (in-degree) and power (eigenvector centrality). We suggest that the study of automated agents should include designer intentions, the design and behavior of automated agents, user expectations, as well as unintended and incidental effects of interaction

AN ADAPTIVE MANAGEMENT APPROCAH TO CONTROL SPREAD OF INVASIVE ALIEN SPECIES IN BUNDALA RAMSAR WETLAND IN SRI LANKA

Habitat degradation due to invasive plant species is identified as one of themajor threats in several protected areas managed by Department of WildlifeConservation in Sri Lanka. Bundala National Park, covering an area of 6216ha is located about 250 km Southeast of Colombo (06°08' - 06°14' N, 81°08'- 81°18'). The Bundala National Park is Sri Lanka's first Wetland ofInternational importance declared under the Ramsar Convention. The parkconsists of mainly dry thorny scrubland and lagoons, which are shallowbrackish water lagoons. They harbours a rich bird life including severalspecies of migratory waterfowls. It also contains key nesting sites for fivespecies of marine turtles. Arid and semiarid terrestrial habitats shelter a widerange of species, including elephants and other mammals, reptiles,amphibians and fish species. The introduced Prosopis julifolia, a tree speciesnative to Central and South America as a fuel wood in home gardens by theForest Department has expanded its distribution and has invaded the BundalaNational Park. There are large stands of Prosopis julifolia that prevents thegrowth of other indigenous species. Furthermore it invades the lagoon and asa result the area covered by the lagoon is also being reduced. Opuntia strictavar. dillenii, which is also a plant native to Central America, is used mainlyas a hedge species around human dwellings and from there it may haveinvaded wetland habitats in Bundala National Park.The spread of these invasive alien plant species has resulted in theprogressive deterioration of wildlife habitats and native biodiversity in thepark, and hence warranting immediate management to curtail their spread.The general methodology adopted for the invasive plant managementprogramme in Sri Lanka is based on adaptive management techniques.Adaptive management is a process that involves planning, management andmonitoring to provide a framework for testing assumptions, adaptation andlearning. Invasive species were eradicated manually and mechanically. Lackof a planned systematic research programme to compile field observations inareas subjected to invasive plant management is a major constraint. Inaddition, views of non-scientific public and lack of funds for adaptivemanagement techniques are the major constraint

Synthesis And Characterization Of Silver Nanoparticles For Antimicrobial Application In Natural Rubber Latex Foam By

In this research project, natural rubber latex foam materials (NRLF) were developed with antimicrobial properties built-in within the natural rubber latex foam matrix by incorporating silver based nanomaterials using different techniques. The initial attempt was to optimize the chemical synthesis method of silver nanoparticles (SNPs) by varying the process parameters such as proportionate of reactant silver nitrate and tri-sodium citrate (TrSC), time of the reaction and the temperature conditions. It was found that, as the amount of TrSC was increased the obtained silver nanocolloid was more stable and consisted with mono-dispersed smaller sized SNPs. Next it was found that the incorporation of SNPs into the NRLF matrix can be accomplished via several techniques such as in-situ deposition of silver nanoparticles on NRLF (method 1), direct compounding method (method 2), using silver nanoparticles incorporated potassium oleate soap as both foaming and convenient carrier materials (method 3), green synthesis of silver nanoparticles inside natural rubber latex (method 4) and finally by incorporating silver doped titanium nanoparticles (Ag_doped TiO2) (method 5). It was found that the method 1 is the best method to incorporate smaller sized and consistently distributed SNPs into the natural rubber latex foam whereas the method 4 shows novel and easy way to incorporate SNPs into the NRLF. In addition, the last method showed the highest antimicrobial activities even though that method is difficult to carry out in large scale xxvii synthesis. It is observed that modified NRLF materials via all the five methods showed remarkable antimicrobial and anti-fungal properties against various kinds of pathogenic micro-organisms including Gram negative (G-) Escherichia coli (E.coli), Gram positive (G+) Staphylococcus aureus (SA), Staphylococcus epidermidis (SE) and Aspergillus niger (A. niger). Results obtained from the method 3, revealed the novel synthesis method of SNPs inside potassium oleate resulted soap material that can be directly used as an antimicrobial carboxylate soap. Results obtained from the method 4 confirmed that the novel green synthesis method of silver nanoparticles inside natural rubber latex can be easily carried out without using an additional stabilizing agent or a reducing agent. Furthermore it was found that the Ag doped TiO2 enhanced antimicrobial activities of NRLF by a great extent even in dark conditions

Species Composition and Visiting Frequencies of Flower Visitors of Chromolaena odorata

Plant-animal interaction has been a major theme in ecology as it has helped ecologists to rule out different patterns they observed in the surrounding environments. Chromolaena odorata is another plant species that is studied extensively as it has become a major troublesome weed in many parts of the tropics. But, handful of studies are available on pollination of this invasive plant species in dry forests and its function as a pollinator sink in these environments. The current study was carried out in a dry zone secondary forest patch in North-Central Sri Lanka to assess the diversity, abundance, and pollination strength of flower visitors associated with the C. odorata. The results suggest that the diversity of Hymenoptera and Lepidoptera is higher than the other insect orders that visited C. odorata, but all species exerted equal pollination strength on the plant. The attraction of large numbers of insects is concluded to as one of the factors that contribute to the reproductive success of C. odorata in dry zone forests

Investigation of timber utilization properties of Khaya senegalensis and Switenia macrophylla

As the need for wood and wood products is steadily rising, both the private and government sectors have increasingly become interested in introducing new, commercially valuable, fast growing timber species. A major drawback for the efficient utilization and promotion of new species is the lack of information regarding their wood properties when grown under local conditions. The present work was designed to investigate some wood properties of Khaya senegalensis , which has been established by the Forestry Department and much familiar Swetenia macrophylla.Three trees each from three crown classes (suppressed, co dominant, dominant) from 62 years old K. senegalensis were studied. Three trees from 88 years old S. macrophylla were also studied which belong to co-dominant class. Log end splits were measured from the extracted boles. Sample disks were extracted at breast height from each tree and pith eccentricity, heartwood percentage and colour were measured. Radial variations of density and shrinkage were studied at percentage distances from pith to bark. To investigate the effect of growth rate on specific gravity, ring width and specific gravity were measured from the extracted disks from breast height.Colour of the heartwood of K. senegalensis was reddish brown and sap wood was pinkish white. In S. macrophylla heartwood was reddish yellow and sap wood was yellow. Log end splits were higher in K.senegalensis. Pith eccentricity and heartwood percentage values were higher in S. macrophylla. According to the results, the general pattern of radial variation of specific gravity in both K. senegalensis and S. macrophylla was similar: remaining more or less uniform from pith to bark. It was observed that the two species show a gradual increase of volumetric shrinkage from pith to barkThe mean ring width values of K. senegalensis for suppressed (3.92 mm), co-dominant (6.09 mm) dominant (7.02 mm) crown classes were significantly different. The mean specific gravity for these classes (0.654, 0.602 and 0.686) was also significantly different. But no significant relationship between ring width (growth rate) and specific gravity was found among each crown class. The mean ring width and specific gravity values of K. senegalensis were compared with the initial 33 years of co-dominant trees of the S.macrophylla. The mean ring width value obtained for the K. senegalensis (5.67 mm) was significantly higher than the mean ring width of S. macrophylla (4.32 mm).Also specific gravity of K. senegalensis (0.647) was significantly higher than S. macrophylla (0.577). Therefore, it can be concluded that growth rate and specific gravity are higher in K. senegalensis compared with S. macrophylla. Hence this initial study suggests that recently introduced K. sengalenis will produce better quality timber in term of specific gravity at a faster rate compared with presently popular species S. macrophylla. However other factors such as colour and appearance and market acceptability should also be explored

Comparison of serum concentrations of interleukin-8 and carcinoembryonic antigen in a south Asian cohort of patients with colorectal cancer

OBJECTIVE: Colorectal cancer (CRC) is the third most common cancer type in the world. Carcinoembryonic antigen (CEA) is widely used as a marker for CRCs. Interleukin-8 (IL-8) is a pro-inflammatory cytokine noticeably up-regulated in CRCs. Research have been conducted in different populations to investigate the CEA and IL-8 levels in CRCs and to elucidate their correlation with clinical findings. However, data on Sri Lankan CRC patients are sparse; none reports the CEA or IL-8 levels or their correlations with clinical findings. The objective of this study was to compare the CEA and IL-8 levels in a cohort of CRC patients. PATIENTS AND METHODS: Blood samples from forty patients with CRCs and thirty-five healthy volunteers were obtained after informed consent. Their clinical findings and CEA values were recorded. The concentrations of IL-8 were measured using enzyme-linked immunosorbent assay (ELISA). The mean values of IL-8 levels in patients and the control group were compared and the data were analysed to evaluate if there is a correlation between CEA and IL8 levels. RESULTS: At the time of diagnosis, most of the tumors were moderately differentiated (83%) and the average tumor length was 4.4 cm. The tumor location was mostly left-sided (88.7%). Mean CEA level was 21.3 ng/dl at the diagnosis. Mean [IL-8] in patients was 38.16 pg/ml and was higher than that of controls (33.67 pg/ml). However, the difference was not statistically significant (p > 0.05). Additionaly, a strong positive correlation between [CEA] and [IL8] was not observed (r=0.19). CONCLUSIONS: This study shows that most of the CRCs are diagnosed at moderately differentiated stage with high CEA values. The results of this study are in favor of using CEA as a diagnostic marker. It provided no evidence of a correlation between high CEA and IL-8. Even though not significantly different from that of controls, elevated IL-8 could be a potential marker for CRCs which needs further validation by higher sample numbers

Design and development of power tiller operated multipurpose whole stick harvester especially for sugarcane

In Sri Lanka cane harvesting is done manually using various types of hand knives. This method ofharvesting not only consumes much time but also requires much skilled labourers. But nowadayslabourers are becoming scarce and costly, particularly in sugarcane cultivation areas. This is due todiversion oflabour to other more remunerative work in industry, construction, business and diversionof labour to other crops.It is difficult to employ heavy machines in Sri Lanka due to various reasons such as, fragmented andsmall holdings with small and irregular fields, diverse cropping patterns followed, the cultivation practices which have been developed for manual harvest and poor farmers who cannot afford costly machines.Therefore Power tiller operated whole stick harvester prototype was designed and constructed. Thedesigned machine consists of reversible cutting device, power transmission unit with clutch mechanismand Cane shifting device. The Maximum cutting width, Machine capacity and Traveling speed wereconsidered as criteria for comparison of merits and demerits with existing manual method. The resultsshowed that maximum cutting width, Machine capacity and Traveling speed were 1.2m, 0.8 ha/dayand 0.75 km/hr respectively. The cost of production of the designed Sugarcane harvester wasRs.20,OOO.0