Detection of Stock Manipulation Influencer Content using Supervised Learning

In recent years, social media influencers have emerged as key players in stock manipulation schemes. Despite their growing impact, methods to detect such activities remain scarcely explored. In this study, we examine the social media content of stock manipulation influencers (SMIs) implicated in a $100 million fraud case by the U.S. Securities and Exchange Commission (SEC) in 2022. Leveraging natural language processing (NLP) techniques, we first investigate the linguistic characteristics present in the social media content published by SMIs. Next, we develop and evaluate supervised learning models to detect manipulative content. Our results have significant implications for investors, regulators, and the broader financial community. They reveal the unique linguistic characteristics of SMI content and demonstrate the potential of machine-learning and deep-learning-based techniques in advancing fraud detection systems

FINFLUENCERS: OPINION MAKERS OR OPINION FOLLOWERS?

This paper explores the concept of Finfluencers: financial social network actors with high potential social influence. Our research aims to clarify whether Finfluencers drive or are influenced by the broader social network sentiment, thereby establishing their role as either opinion makers or opinion followers. Using a dataset of 71 million tweets focusing on stocks and cryptocurrencies, we grouped actors by their social networking potential (SNP). Next, we derived sentiment time series using state-ofthe- art sentiment models and applied the technique of Granger causality. Our findings suggest that the sentiment of Finfluencer actors on Twitter has short-term predictive power for the sentiment of the larger group of actors. We found stronger support for cryptocurrencies in comparison to stocks. From the perspective of financial market regulation, this study emphasizes the relevance of understanding sentiment on social networks and high social influence actors to anticipate scams and fraud

Genotype-Independent Transmission of Transgenic Fluorophore Protein by Boar Spermatozoa

Recently, we generated transposon-transgenic boars (Sus scrofa), which carry three monomeric copies of a fluorophore marker gene. Amazingly, a ubiquitous fluorophore expression in somatic, as well as in germ cells was found. Here, we characterized the prominent fluorophore load in mature spermatozoa of these animals. Sperm samples were analyzed for general fertility parameters, sorted according to X and Y chromosome-bearing sperm fractions, assessed for potential detrimental effects of the reporter, and used for inseminations into estrous sows. Independent of their genotype, all spermatozoa were uniformly fluorescent with a subcellular compartmentalization of the fluorophore protein in postacrosomal sheath, mid piece and tail. Transmission of the fluorophore protein to fertilized oocytes was shown by confocal microscopic analysis of zygotes. The monomeric copies of the transgene segregated during meiosis, rendering a certain fraction of the spermatozoa non-transgenic (about 10% based on analysis of 74 F1 offspring). The genotype-independent transmission of the fluorophore protein by spermatozoa to oocytes represents a non-genetic contribution to the mammalian embryo

Profiling Cryptocurrency Pump and Dump Schemes in DeFi: A Chain-Level Analysis of Coins and Participants

Pump and dump (P&D) schemes are a phenomenon known from stock trading that quickly expanded into cryptocurrency trading. Several studies dealt with analysis and prediction models related to such schemes in cryptocurrencies already, but only few researchers made use of data related to the underlying transactions available on decentralized exchanges (DEXs). In line with current calls to action, we apply both value and transaction analytics to profile P&D schemes and derive insights on coins as well as participant behavior during such activities. Based on the analysis of over 1.3M transactions related to 288 cryptocurrencies traded on DEXs and 314 P&D attempts, we find that particular cryptocurrencies are more frequently targeted by P&D activities than others and some seem specifically designed for that purpose. Our work contributes to the growing research on fraud in financial markets and characterizes actors and their behavior at the blockchain level

Influence of gold, silver and gold–silver alloy nanoparticles on germ cell function and embryo development

The use of engineered nanoparticles has risen exponentially over the last decade. Applications are manifold and include utilisation in industrial goods as well as medical and consumer products. Gold and silver nanoparticles play an important role in the current increase of nanoparticle usage. However, our understanding concerning possible side effects of this increased exposure to particles, which are frequently in the same size regime as medium sized biomolecules and accessorily possess highly active surfaces, is still incomplete. That particularly applies to reproductive aspects, were defects can be passed onto following generations. This review gives a brief overview of the most recent findings concerning reprotoxicological effects. The here presented data elucidate how composition, size and surface modification of nanoparticles influence viablility and functionality of reproduction relevant cells derived from various animal models. While in vitro cultured embryos displayed no toxic effects after the microinjection of gold and silver nanoparticles, sperm fertility parameters deteriorated after co-incubation with ligand free gold nanoparticles. However, the effect could be alleviated by bio-coating the nanoparticles, which even applies to silver and silver-rich alloy nanoparticles. The most sensitive test system appeared to be in vitro oocyte maturation showing a dose-dependent response towards protein (BSA) coated gold–silver alloy and silver nanoparticles leading up to complete arrest of maturation. Recent biodistribution studies confirmed that nanoparticles gain access to the ovaries and also penetrate the blood–testis and placental barrier. Thus, the design of nanoparticles with increased biosafety is highly relevant for biomedical applications

The in Vitro Effect of Taurine on Boar Spermatozoa Quality

The aim of this in vitro study was to evaluate the effects of taurine (TAU) supplementation on boar spermatozoa motility, viability, acrosome integrity and morphology. Eighteen boar semen samples were diluted with the Androhep PlusTM extender containing no TAU (control) or supplemented with 1.5 mM, 7 mM, 12.5 mM TAU and cultured at 4 °C for 18 days. Sperm motility was evaluated using the computer-aided sperm analysis (CASA) system. Furthermore, the samples were fixed and assessed for the occurrence of morphological abnormalities using phase contrast microscopy. Fluorescent dyes SYBR – 14 and propidium iodide were used to determine the sperm viability. Acrosome integrity was examined using PNA – Alexa Fluor 647 and flow cytometry. A gradual decrease of the semen quality was detected in all experimental groups over the course of the study. CASA revealed no selective advantage of TAU supplementation on the spermatozoa motility (p > 0.05). TAU administration showed to be ineffective in preserving spermatozoa viability as well as acrosome integrity as measured by flow cytometry (p > 0.05). Under the conditions of this study, no significant positive effect of TAU was recorded following its administration to the Androhep PlusTM boar semen extender with respect to spermatozoa quality

Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

Due to the abundance of nanomaterials in medical devices and everyday products, toxicological effects related to nanoparticles released from these materials, e.g., by mechanical wear, are a growing matter of concern. Unfortunately, appropriate nanoparticles required for systematic toxicological evaluation of these materials are still lacking. Here, the ubiquitous presence of surface ligands, remaining from chemical synthesis are a major drawback as these organic residues may cause cross-contaminations in toxicological studies. Nanoparticles synthesized by pulsed laser ablation in liquid are a promising alternative as this synthesis route provides totally ligand-free nanoparticles. The first part of this article reviews recent methods that allow the size control of laser-fabricated nanoparticles, focusing on laser post irradiation, delayed bioconjugation and in situ size quenching by low salinity electrolytes. Subsequent or parallel applications of these methods enable precise tuning of the particle diameters in a regime from 4–400 nm without utilization of any artificial surface ligands. The second paragraph of this article highlights the recent progress concerning the synthesis of composition controlled alloy nanoparticles by laser ablation in liquids. Here, binary and ternary alloy nanoparticles with totally homogeneous elemental distribution could be fabricated and the composition of these particles closely resembled bulk implant material. Finally, the model AuAg was used to systematically evaluate composition related toxicological effects of alloy nanoparticles. Here Ag+ ion release is identified as the most probable mechanism of toxicity when recent toxicological studies with gametes, mammalian cells and bacteria are considered