Impact of Stricter Content Moderation on Parler's Users' Discourse

Social media platforms employ various content moderation techniques to remove harmful, offensive, and hate speech content. The moderation level varies across platforms; even over time, it can evolve in a platform. For example, Parler, a fringe social media platform popular among conservative users, was known to have the least restrictive moderation policies, claiming to have open discussion spaces for their users. However, after linking the 2021 US Capitol Riots and the activity of some groups on Parler, such as QAnon and Proud Boys, on January 12, 2021, Parler was removed from the Apple and Google App Store and suspended from Amazon Cloud hosting service. Parler would have to modify their moderation policies to return to these online stores. After a month of downtime, Parler was back online with a new set of user guidelines, which reflected stricter content moderation, especially regarding the \emph{hate speech} policy. In this paper, we studied the moderation changes performed by Parler and their effect on the toxicity of its content. We collected a large longitudinal Parler dataset with 17M parleys from 432K active users from February 2021 to January 2022, after its return to the Internet and App Store. To the best of our knowledge, this is the first study investigating the effectiveness of content moderation techniques using data-driven approaches and also the first Parler dataset after its brief hiatus. Our quasi-experimental time series analysis indicates that after the change in Parler's moderation, the severe forms of toxicity (above a threshold of 0.5) immediately decreased and sustained. In contrast, the trend did not change for less severe threats and insults (a threshold between 0.5 - 0.7). Finally, we found an increase in the factuality of the news sites being shared, as well as a decrease in the number of conspiracy or pseudoscience sources being shared

Understanding the Bystander Effect on Toxic Twitter Conversations

In this study, we explore the power of group dynamics to shape the toxicity of Twitter conversations. First, we examine how the presence of others in a conversation can potentially diffuse Twitter users' responsibility to address a toxic direct reply. Second, we examine whether the toxicity of the first direct reply to a toxic tweet in conversations establishes the group norms for subsequent replies. By doing so, we outline how bystanders and the tone of initial responses to a toxic reply are explanatory factors which affect whether others feel uninhibited to post their own abusive or derogatory replies. We test this premise by analyzing a random sample of more than 156k tweets belonging to ~9k conversations. Central to this work is the social psychological research on the "bystander effect" documenting that the presence of bystanders has the power to alter the dynamics of a social situation. If the first direct reply reaffirms the divisive tone, other replies may follow suit. We find evidence of a bystander effect, with our results showing that an increased number of users participating in the conversation before receiving a toxic tweet is negatively associated with the number of Twitter users who responded to the toxic reply in a non-toxic way. We also find that the initial responses to toxic tweets within conversations is of great importance. Posting a toxic reply immediately after a toxic comment is negatively associated with users posting non-toxic replies and Twitter conversations becoming increasingly toxic

User Engagement and the Toxicity of Tweets

Twitter is one of the most popular online micro-blogging and social networking platforms. This platform allows individuals to freely express opinions and interact with others regardless of geographic barriers. However, with the good that online platforms offer, also comes the bad. Twitter and other social networking platforms have created new spaces for incivility. With the growing interest on the consequences of uncivil behavior online, understanding how a toxic comment impacts online interactions is imperative. We analyze a random sample of more than 85,300 Twitter conversations to examine differences between toxic and non-toxic conversations and the relationship between toxicity and user engagement. We find that toxic conversations, those with at least one toxic tweet, are longer but have fewer individual users contributing to the dialogue compared to the non-toxic conversations. However, within toxic conversations, toxicity is positively associated with more individual Twitter users participating in conversations. This suggests that overall, more visible conversations are more likely to include toxic replies. Additionally, we examine the sequencing of toxic tweets and its impact on conversations. Toxic tweets often occur as the main tweet or as the first reply, and lead to greater overall conversation toxicity. We also find a relationship between the toxicity of the first reply to a toxic tweet and the toxicity of the conversation, such that whether the first reply is toxic or non-toxic sets the stage for the overall toxicity of the conversation, following the idea that hate can beget hate

SoK: Content Moderation in Social Media, from Guidelines to Enforcement, and Research to Practice

To counter online abuse and misinformation, social media platforms have been establishing content moderation guidelines and employing various moderation policies. The goal of this paper is to study these community guidelines and moderation practices, as well as the relevant research publications to identify the research gaps, differences in moderation techniques, and challenges that should be tackled by the social media platforms and the research community at large. In this regard, we study and analyze in the US jurisdiction the fourteen most popular social media content moderation guidelines and practices, and consolidate them. We then introduce three taxonomies drawn from this analysis as well as covering over one hundred interdisciplinary research papers about moderation strategies. We identified the differences between the content moderation employed in mainstream social media platforms compared to fringe platforms. We also highlight the implications of Section 230, the need for transparency and opacity in content moderation, why platforms should shift from a one-size-fits-all model to a more inclusive model, and lastly, we highlight why there is a need for a collaborative human-AI system

Utilizing Radiomic Feature Analysis For Automated MRI Keypoint Detection: Enhancing Graph Applications

Graph neural networks (GNNs) present a promising alternative to CNNs and transformers in certain image processing applications due to their parameter-efficiency in modeling spatial relationships. Currently, a major area of research involves the converting non-graph input data for GNN-based models, notably in scenarios where the data originates from images. One approach involves converting images into nodes by identifying significant keypoints within them. Super-Retina, a semi-supervised technique, has been utilized for detecting keypoints in retinal images. However, its limitations lie in the dependency on a small initial set of ground truth keypoints, which is progressively expanded to detect more keypoints. Having encountered difficulties in detecting consistent initial keypoints in brain images using SIFT and LoFTR, we proposed a new approach: radiomic feature-based keypoint detection. Demonstrating the anatomical significance of the detected keypoints was achieved by showcasing their efficacy in improving registration processes guided by these keypoints. Subsequently, these keypoints were employed as the ground truth for the keypoint detection method (LK-SuperRetina). Furthermore, the study showcases the application of GNNs in image matching, highlighting their superior performance in terms of both the number of good matches and confidence scores. This research sets the stage for expanding GNN applications into various other applications, including but not limited to image classification, segmentation, and registration

Price discovery mechanism and volatility spillover between national agriculture market and national commodity and derivatives exchange : the study of the Indian agricultural commodity market

Agricultural commodity markets are critical to the global economy. This study investigates the price discovery mechanism, lead-lag relationship, and volatility spillover between spot prices on the National Agriculture Market (E-NAM) and futures and spot prices on the National Commodity and Derivative Exchange (NCDEX) in the Indian agricultural commodity market. The Johansen Cointegration, Vector Error Correction (VEC), Granger causality tests, and bivariate GARCH models were applied to daily data from April 2016 to December 2020 for twelve agricultural commodities traded on the E-NAM and NCDEX. We discovered the long-run relationship using the Johansen Cointegration test and concluded that the NCDEX spot and futures market is dominant in the price discovery mechanism, and the NCDEX futures and spot markets lead the E-NAM spot prices having a unidirectional or bidirectional relationship. Furthermore, the bivariate GARCH model suggested a volatility spillover from E-NAM spot prices to NCDEX futures and spot markets for most commodities, except for bajra, barley, and jeera, which have no volatility spillover. The study’s findings have important implications for various stakeholders, including policymakers, farmers, investors, traders, and others who want to reduce price risks by using information from the E-NAM market’s spot prices.peer-reviewe

A comparative analysis of the findings of postmortem computed tomography scan and traditional autopsy in traumatic deaths: Is technology mutually complementing or exclusive?

Background: Postmortem examination is indispensable to ascertain the cause of an unnatural death and as such is mandatory by the law. From ages, traditional autopsy (TA) has proved its worth in establishing the cause of death in the deceased despite some inherent difficulties and challenges and has enjoyed an insurmountable status. The increasing use of application of the modern-day radiology for postmortem examination has however opened a new arena overcoming some of the difficulties of the TA. There are conflicting reports in the published literature regarding superiority of one modality of the postmortem over the other. Objective: The objective of this study was to compare the findings of postmortem computed tomography (CT) scan and TA in the victims of traumatic deaths and to analyze whether postmortem CT can be used to replace TA. Materials and Methods: All patients with a history of trauma that were declared brought dead on arrival in the emergency department were subjected to full-body CT scan. An experienced radiologist reported the findings of CT scan. Subsequently, a forensic expert subjected the patients to TA. The physician who performed autopsy was blinded to the findings of CT scan and vice versa. An individual who was not part of the radiology or forensic team then entered the findings of CT scan and autopsy in a predesigned Pro forma. An unbiased assessor finally compared the findings of the two modalities and analyzed the results. McNemar's test was used to ascertain the level of significance between the findings reported by these two modalities considering P = 0.05 as statistically significant. The agreement or disagreement on cause of death reported by these two modalities was also assessed. Results: About 95 of the deceased were males. The mean age of the corpses was 35 years (range 1667 years). CT was found superior in picking up most of the bony injuries, air-containing lesions, hemothorax, and hemoperitoneum. However, autopsy was found more sensitive for soft-tissue and solid visceral injuries. Both modalities were equally helpful in identifying extremity fractures. Statistically significant agreement (>95) on cause of death by both modalities was not achieved in any patient of trauma. Conclusion: Postmortem CT scan is promising in reporting injuries in traumatic deaths and can significantly complement the conventional autopsy. However, at present, it cannot be considered as a replacement for TA

Experimental Investigation of Controlled Single and Multiple Impacts of Shot Peening on Titanium Ti-6A1-4V Alloy, 300M Steel and Aluminium Alloy 7050-T7451

Résumé Pendant le processus de grenaillage, plusieurs coups sphériques impactent la surface du composant à des vitesses élevées provoquant une déformation plastique de la surface du composant. Cette déformation plastique introduit des contraintes résiduelles de compression bénéfiques sous la surface dans le matériau et, dans certains cas, augmente la dureté sous la surface en raison de l’évolution de la microstructure sous la surface, améliorant durée de vie et résistance à l’usure. Le processus de grenaillage est régi par un certain nombre d’imparamètres importants qui déterminent le rendement de grenaillage. Pour mieux comprendre le coup processus de grenaillage et résultats de grenaillage sur différents matériaux, il est essentiel d’étudier l’effet de paramètres de processus individuels pour différents matériaux cibles. En utilisant un canon de grenaillage à un seul coup, l’effet des paramètres de grenaillage individuels tels que comme la vitesse de tir, le diamètre de tir, l’angle d’impact et les propriétés du matériau sur l’indentation diamètre, profondeur d’indentation et changement de la valeur du coefficient de restitution (CoR) après un et trois impacts sur les alliages aérospatiaux sont étudiés. La recherche porte sur trois différents alliages : alliage Titane Ti- 6Al-4V, acier 300 M (fourni par SAFRAN Tech.) et Alliage d’aluminium AA 7050-T7451. La vitesse et la taille du tir, l’angle d’impact et les qualités du matériau cible sont tous paramètres pertinents, selon la littérature. Pour grenailler les échantillons, 1,19 mm et Des tailles de grenailles de 2,5 mm en acier inoxydable 440 HRC ont été choisies. Au cours de la procédure de grenaillage, une pression de canon allant de 0,013 MPa à 0,55 MPa a été utilisée. Pour l’expérimentation analyse, trois angles d’impact de 0°, 15° et 30° ont été choisis. Deux haute résolution des radars ont été utilisés pour analyser la trajectoire 3D du tir. Caméras haute résolution ont été utilisés pour mesurer l’impact et la vitesse de rebond du tir impactant. Les principales conclusions de l’étude sont que l’augmentation de la pression des canons entraîne une exposition inverse. augmentation essentielle de la vitesse d’impact. La vitesse moyenne passe de 16,4 m/s à 82,1 m/s pour le diamètre de grenaille de 2,5 mm et 9,7 m/s à 57,7 m/s pour le diamètre de grenaille de 1,19 mm lorsque la pression est augmentée de 0,01 MPa à 0,55 MPa. L’angle d’impact réel variait entre +14° pour un angle cible de 0°, ± 8° pour un angle cible de 15° et ±4° pour un angle cible de 30°. Le diamètre et la profondeur d’indentation sont influencés par le diamètre de la taille de la grenaille et l’impact de la grenaille rapidité. Dans le cas d’une interaction tir-cible d’un diamètre de tir de 2,5 mm, l’augmentation de la vitesse de 16,4 m/s à 82,1 m/s entraîne une augmentation du diamètre moyen de l’indentation dans le titane Ti-6Al-4V de 522,83 μm à 1073,3 μm soit seulement 183,12 μm à 432 μm avec 1,19 coup de mm. De même, pour l’acier 300M, le diamètre moyen passe de 465 μm à 1023,3 μm viii pour un diamètre de grenaille de 2,5 et de 181,4 μm à 416,83 μm pour un diamètre de grenaille de 1,19 mm. Aluminium L’alliage AA7050 T-7451 a observé un changement significativement plus élevé du diamètre d’indentation moyen soit 619,83 μm à 1403,6 μm pour un diamètre de grenaille de 2,5 mm et 233,66 μm à 578,6 μm pour diamètre de tir 1,19 mm. Pour vérifier le diamètre de l’indentation, les résultats ont été en outre analysés et comparés avec les deux autres techniques telles que l’analyse des contours GT et analyse de polissage conventionnelle. L’échantillon d’essai grenaillé à 0,06 MPa et 0,27 MPa avec 2,5 mm a été utilisé pour l’analyse. On observe qu’en mesurant l’indentation diamètre, l’erreur maximale avec la technique de l’échantillon de coupe est de 25 % lors de l’utilisation du contour GT analyse, l’erreur maximale pourrait être de 15%. Le diamètre de tir, les angles d’impact de l’incident, les vitesses de tir et le nombre d’impacts ont tous eu un impact sur la valeur du coefficient de restitution (CoR), qui a été mesuré et comparé. Pour résumer, le diamètre du tir n’a pas d’effet sur la valeur du CoR, cependant l’impact l’angle, la vitesse de tir et le nombre d’impacts ont tous un effet sur la valeur CoR. Le CdR la valeur varie de 0,30 à 0,89. La valeur du CoR augmente avec le nombre d’impacts dans le même région augmente. Le diamètre d’indentation augmente à mesure que la vitesse d’impact augmente et le diamètre de la grenaille passe de 1,19 mm à 2,5 mm. La vitesse d’impact varie moins inférieure à ±5 m/s pour une pression d’impact donnée. ---------- Abstract During the shot peening process, multiple spherical shots impact the component surface at high speeds causing plastic deformation of the component surface. This plastic deformation introduces beneficial sub-surface compressive residual stresses into the material and, in some cases, increases sub-surface hardness due to sub-surface microstructure evolution, improving fatigue life and wear resistance. The shot peening process is governed by a number of important parameters that determine the shot peening output. To better understand the shot peening process and peening results on different materials, it is critical to study the effect of individual process parameters for different target materials. Using a single-shot peening cannon, the effect of individual shot peening parameters such as shot velocity, shot diameter, angle of impact, and material properties on indentation diameter, indentation depth, and change in the coefficient of restitution (CoR) value after a single and three impacts on aerospace alloys is investigated. The research focus on three different alloys: Titanium Ti-6Al-4V Alloy, 300M Steel (supplied by SAFRAN Tech.) and Aluminum Alloy 7050-T7451. The shot velocity and size, the angle of impact, and the target material characteristics are all relevant parameters, according to the literature. To shot peen the samples, 1.19 mm and 2.5 mm stainless steel 440 HRC shot sizes were chosen. During the shot peening procedure, a cannon pressure ranging from 0.013 MPa to 0.55 MPa was used. For the experimental analysis, three impact angles of 0°, 15°, and 30° were chosen. Two high-resolution highspeed cameras were utilised to analyse the shot’s 3D trajectory. High-resolution cameras were used to measure the impact and rebound velocity of the impacting shot. The study’s main conclusions are that increasing cannon pressure causes an inverse exponential increase in impact velocity. The mean velocity increases from 16.4 m/s to 82.1 m/s for the shot diameter of 2.5 mm and 9.7 m/s to 57.7 m/s for the shot diameter of 1.19 mm when the pressure is increased from 0.01 MPa to 0.55 MPa. The true impacting angle varied between +14° for 0° target angle, ± 8° for 15° target angle and ±4° for 30° target angle. Indentation diameter and depth are influenced by shot size diameter and shot impacting velocity. In the case of shot-target interaction of 2.5 mm shot diameter, the increase in velocity from 16.4 m/s to 82.1 m/s results in increasing mean diameter of indentation in Titanium Ti-6Al- 4V Alloy from 522.83 μm to 1073.3 μm which is only 183.12 μm to 432 μm with 1.19 mm shot. Similarly, for 300M Steel, the mean diameter increases from 465 μm to 1023.3 μm for 2.5 shot diameter and 181.4 μm to 416.83 μm for 1.19 mm shot diameter. Aluminum Alloy 7050-T7451 observed a significantly higher change in mean indentation diameter i.e. 619.83 μm to 1403.6 μm for shot diameter 2.5 mm and 233.66 μm to 578.6 μm for shot diameter 1.19 mm. To verify the diameter of the indentation, the results were further analysed and compared with the other two techniques such as Contour GT analysis and conventional polishing analysis. The test sample shot peened at 0.06 MPa and 0.27 MPa with 2.5 mm has been used for the analysis. It is observed that in measuring indentation diameter, the maximum error with cutting sample technique was 25 % while using contour GT analysis the maximum error could be 15 %. Shot velocity, shot size, incident impacting angle and the number of impacts all had an impact on the CoR value, which was measured and compared. To summarise, the diameter of the shot has no effect on the CoR value, however the impact angle, shot velocity, and the number of impacts all has an effect on the CoR value. The CoR value ranges from 0.30 to 0.89. The CoR value increases as the number of impacts in the same region increases. The indentation diameter increases as the impacting velocity increases and the shot diameter increases from 1.19 mm to 2.5 mm. The impact velocity varies less than ±5 m/s for a given impact pressure

Preparation and X-Ray Crystallographic Studies of Copper N-Methylimidazole Complexes with Substituted N-Phthaloylalaninato Ligands

Quasiracemates contain two molecules (or ions) of opposite handedness, in which one enantiomer has a substitution of a chemically different, but similarly shaped group. Metal based complexes that are enantiomeric, racemic and quasiracemic were synthesized. Racemic metal compounds are synthesized from equimolar concenteration of chemically identical ligands having both handedness (R and S). Quasiracemic metal complexes were synthesized from two stercially similar, but chemically different ligands, and these complexes tend to mimic the centrosymmetric pattern in racemic metal complexes. This project was begun by previous master’s student, Hiral Patel, to study the crystal packing of metal based quasiracemic complexes, and the goal of this study was to extend this approach. Substituted A-phthaloylalanines were synthesized and characterized by 1H-NMR. Anions of these compounds and A-methylimdiazole are used as ligands to prepare metal complexes with a square planar geometry about copper. Two new crystal structures and one improved structure previously done determined. The new structures are (1) a new quasiracemate, bis(A-methylimidazole)((D)-3-chloro-A-pthaloyalaninato)(( L)-3-nitro-phthaloylalaninato)copper(II), Cu(7,D)(9,L)(JV-MeIm)2, (2) a racemate, bis(A-methylimidazole)bis((D,L)-3-methyl-vV-pthaloylalaninato)-copper(II), Cu(2,D,L)2(A-MeIm)2, and (3) an improved structure of quasiracemate, bis(Amethylimidazole)(( D)-3-chloro-7V-phthaloyalaninato)((L)-3-methyl-phthaloylalaninato)- copper(II) Cu(7,D)(2,L)(A-MeIm)2. The chloro and nitro groups are disordered in both the quaisracemic complexes and the methyl phthaloyl ring is disordered over three and two positions in the quaisracemic and the racemic complexes, respectively. Analysis of the structures showed that crystal packing of quaisracemic and racemic complexes is similar, whereas the enantiomeric complex has a different packing pattern