"Visual Affluence" in social photography: applicability of image segmentation as a visually oriented approach to study Instagram hashtags

The aim of the study is to examine the applicability of image segmentation – identification of objects/regions by partitioning images – to examine online social photography. We argue that the need for a meaning-independent reading of online social photography within social markers, such as hashtags, arises due to two characteristics of social photography: 1) internal incongruence resulting from user-driven construction, and 2) variability of content in terms of visual attributes, such as colour combinations, brightness, and details in backgrounds. We suggest visual affluence- plenitude of visual stimuli, such as objects and surfaces containing a variety of colour regions, present in visual imagery- as a basis for classifying visual content and image segmentation as a technique to measure affluence. We demonstrate that images containing objects with complex texture and background patterns are more affluent, while images that include blurry backgrounds are less affluent than others. Moreover, images that contain letters and dark, single-colour backgrounds are less affluent than images that include subtle shades. Mann-Whitney U test results for nine pairs of hashtags showed that seven out of nine pairs had significant differences in visual affluence. The proposed measure can be used to encourage a ‘visually oriented’ turn in online social photography research that can benefit from hybrid methods that are able to extrapolate micro-level findings to macro-level effects

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

Examining the link between social media uses and gratifications, and political tolerance and dogmatism

The ability of social media to enable new uses and gratifications, and to shape political behavior, has not been discussed adequately in the social media literature. Drawing on a previous study by the authors that converts a framework by Sundar and Limperos (2013) into a social media uses and gratifications scale, this article examines the association between social media uses and gratifications, and political dogmatism and tolerance. A sample of 313 American citizens was used to develop two discriminant models. The models showed that social media uses and gratifications can be used to classify users with high or low levels of political dogmatism and tolerance with more than 70 percent accuracy. The results also indicate that while some gratifications, such as filtering, are common to individuals with high dogmatism as well as users with high tolerance, there were differences in the perception of uses and gratifications between these two groups. This shows that social media are open platforms that do not gratify only positive, open‐minded users

Bayesian Inference and Computation

There has been dramatic growth in the development and application of Bayesian inference in statistics. R provides a wide range of functions for data manipulation, calculation, and graphical displays. Moreover, it includes a well-developed, simple programming language that we can extend by adding new functions. The purpose of this paper is to illustrate Bayesian modeling by computations using the R language. These chapters discuss the use of different types of priors, the use of the posterior distribution to perform different types of inferences, and the predictive distribution. The base package of R provides functions to simulate from all of the standard and non standard probability distributions, and these functions can be used simulate from a variety of posterior distribution

Regular Expression Matching and Operational Semantics

Many programming languages and tools, ranging from grep to the Java String library, contain regular expression matchers. Rather than first translating a regular expression into a deterministic finite automaton, such implementations typically match the regular expression on the fly. Thus they can be seen as virtual machines interpreting the regular expression much as if it were a program with some non-deterministic constructs such as the Kleene star. We formalize this implementation technique for regular expression matching using operational semantics. Specifically, we derive a series of abstract machines, moving from the abstract definition of matching to increasingly realistic machines. First a continuation is added to the operational semantics to describe what remains to be matched after the current expression. Next, we represent the expression as a data structure using pointers, which enables redundant searches to be eliminated via testing for pointer equality. From there, we arrive both at Thompson's lockstep construction and a machine that performs some operations in parallel, suitable for implementation on a large number of cores, such as a GPU. We formalize the parallel machine using process algebra and report some preliminary experiments with an implementation on a graphics processor using CUDA.Comment: In Proceedings SOS 2011, arXiv:1108.279

RELATIONSHIP BETWEEN STEM BIOMASS WITH HEIGHT AND DIAMETER OF Pinus caribaea IN THE YAGIRALA FOREST RESERVE

The biomass is an important measurement in commercial forestry maintained to producepulp, paper, chips, fuel wood products etc. The estimation of biomass of the tree is not aneasy task and a few studies were carried out so far on this problem.The present study was conducted in 25 years old pine plantation in Yagirala ForestReserve, situated in low country wet zone. According to the geographical differences ofthe plantation, stratified random sampling was carried out and two 0.05 ha circular plotswere established in each stratum. Altogether 6 plots were used for the data collection.The diameter at the breast height (dbh) and total height were measured for all the trees inthese plots.Biomass of the tree was estimated by extracting core samples at the breast height and midheight of the tree. The density of the core samples was estimated using oven dry weightand green volume of the core samples. When tested, there was no significant differenceof density along the stem. Therefore stem biomass was estimated using the density atbreast height. Also there was no significant density difference between three sites.The regression analysis was used with pooled data to find out the relationship betweenthe stem biomass with the tree diameter and height. Using variables of stem volume (W),total height (h), diameter at breast height (d) and their transformations, several modelswere developed. The best model was selected by testing for the R2 value, standardresidual distribution, modelling efficiency and bias. The best relationship for the stembiomass, total height and diameter at breast height was given by the following equation,which has R2 value of90.3.logW = -0.917 + 2.081ogd + O.0195h

Analysis of Meandering River Morphodynamics Using Satellite Remote Sensing Data—An Application in the Lower Deduru Oya (River), Sri Lanka

River meandering and anabranching have become major problems in many large rivers that carry significant amounts of sediment worldwide. The morphodynamics of these rivers are complex due to the temporal variation of flows. However, the availability of remote sensing data and geographic information systems (GISs) provides the opportunity to analyze the morphological changes in river systems both quantitatively and qualitatively. The present study investigated the temporal changes in the river morphology of the Deduru Oya (river) in Sri Lanka, which is a meandering river. The study covered a period of 32 years (1989 to 2021), using Landsat satellite data and the QGIS platform. Cloud-free Landsat 5 and Landsat 8 satellite images were extracted and processed to extract the river mask. The centerline of the river was generated using the extracted river mask, with the support of semi-automated digitizing software (WebPlotDigitizer). Freely available QGIS was used to investigate the temporal variation of river migration. The results of the study demonstrated that, over the past three decades, both the bend curvatures and the river migration rates of the meandering bends have generally increased with time. In addition, it was found that a higher number of meandering bends could be observed in the lower (most downstream) and the middle parts of the selected river segment. The current analysis indicates that the Deduru Oya has undergone considerable changes in its curvature and migration rates.publishedVersio

Socioeconomic consequences of the COVID‐19 pandemic for people who use drugs

The COVID-19 pandemic triggered widespread socioeconomic hardship, disproportionately impacting disadvantaged populations. People who use illicit drugs are more likely to experience unemployment, homelessness, criminal justice involvement and poorer health outcomes than the general community, yet little is known about the socioeconomic impacts of the pandemic on their lives. To address this gap in the literature, we conducted in-depth interviews with 76 participants from two cohort studies of people who use illicit drugs (people who inject drugs and/or use methamphetamine) in Victoria, Australia. Findings support claims that pandemic-related Social Security supplementary payments and initiatives to reduce homelessness, although not systemically transforming people's lives, produced temporary relief from chronic socioeconomic hardship. Results also indicate how temporary interruptions to drug supply chains inflated illicit drug prices and produced adverse consequences such as financial and emotional stress, which was exacerbated by drug withdrawal symptoms for many participants. Furthermore, increased community demand for emergency food and housing support during the pandemic appeared to reduce participants' access to these services. Our findings about the unintended consequences of pandemic responses on the socioeconomic lives of a group of people who use illicit drugs provide insights into and opportunities for policy reform to redress their entrenched disadvantage

Effects of fungicide 'Mancozeb' on bovine spermatozoa

Session - Health and Hygiene: no. P163Fungicides are used to maximize the production and productivity of modern agriculture. Present work was undertaken to investigate the effect/s of Mancozeb fungicide on bovine spermatozoa. Semen samples were obtained from Jersey bulls (n=6) at the Central Artificial Insemination Station, Kundasale. Preliminary studies were carried out to determine the effective dose and incubation time using 0.01μg/ml, 0.1μg/ml, 1μg/ml and 10μg/ml of pure Mancozeb and 1.0 μg/ml commercial Mancozeb concentrations during 1-4 hours of incubation periods. Sperm motility parameters were investigated using a Computer Assisted Sperm Analysis (CASA) system. Further functional analyses were performed to test the Acrosine ...postprin