125 research outputs found
Ontogeny of the barley plant as related to mutation expression and detection of pollen mutations.
Clustering of mutant pollen grains in a population of normal pollen due to premeiotic mutational events complicates translating mutation frequencies into rates. Embryo ontogeny in barley will be described and used to illustrate the formation of such mutant clusters. The nature of the statistics for mutation frequency will be described from a study of the reversion frequencies of various waxy mutants in barley. Computer analysis by a "jackknife" method of the reversion frequencies of a waxy mutant treated with the mutagen sodium azide showed a significantly higher reversion frequency than untreated material. Problems of the computer analysis suggest a better experimental design for pollen mutation experiments. Preliminary work on computer modeling for pollen development and mutation will be described
ALONE: A Dataset for Toxic Behavior among Adolescents on Twitter
The convenience of social media has also enabled its misuse, potentially
resulting in toxic behavior. Nearly 66% of internet users have observed online
harassment, and 41% claim personal experience, with 18% facing severe forms of
online harassment. This toxic communication has a significant impact on the
well-being of young individuals, affecting mental health and, in some cases,
resulting in suicide. These communications exhibit complex linguistic and
contextual characteristics, making recognition of such narratives challenging.
In this paper, we provide a multimodal dataset of toxic social media
interactions between confirmed high school students, called ALONE (AdoLescents
ON twittEr), along with descriptive explanation. Each instance of interaction
includes tweets, images, emoji and related metadata. Our observations show that
individual tweets do not provide sufficient evidence for toxic behavior, and
meaningful use of context in interactions can enable highlighting or
exonerating tweets with purported toxicity.Comment: Accepted: Social Informatics 202
A comparison of the effects of physical and chemical mutagens in sesame (Sesamum indicum L.)
Three sesame genotypes (Rama, SI 1666 and IC 21706) were treated with physical (γ-rays: 200 Gy, 400 Gy or 600 Gy) or chemical (ethyl methane sulphonate, EMS: 0.5%, 1.0%, 1.5% or 2.0%) mutagens and their mutagenic effectiveness and efficiency were estimated in the M 2 generation. The M 3 generation was used to identify the most effective mutagen and dose for induction of mutations. The average effectiveness of EMS was much higher than γ-rays. The lowest dose of γ-rays (200 Gy) and the lowest concentration of EMS (0.5%) showed the highest mutagenic efficiency in all genotypes. Analysis of the M 3 generation data based on parameters such as the variance ratio and the difference in residual variances derived from the model of Montalván and Ando indicated that 0.5% concentration of EMS was the most effective treatment for inducing mutations
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