An Analysis of Optimal Link Bombs

We analyze the phenomenon of collusion for the purpose of boosting the pagerank of a node in an interlinked environment. We investigate the optimal attack pattern for a group of nodes (attackers) attempting to improve the ranking of a specific node (the victim). We consider attacks where the attackers can only manipulate their own outgoing links. We show that the optimal attacks in this scenario are uncoordinated, i.e. the attackers link directly to the victim and no one else. nodes do not link to each other. We also discuss optimal attack patterns for a group that wants to hide itself by not pointing directly to the victim. In these disguised attacks, the attackers link to nodes $l$ hops away from the victim. We show that an optimal disguised attack exists and how it can be computed. The optimal disguised attack also allows us to find optimal link farm configurations. A link farm can be considered a special case of our approach: the target page of the link farm is the victim and the other nodes in the link farm are the attackers for the purpose of improving the rank of the victim. The target page can however control its own outgoing links for the purpose of improving its own rank, which can be modeled as an optimal disguised attack of 1-hop on itself. Our results are unique in the literature as we show optimality not only in the pagerank score, but also in the rank based on the pagerank score. We further validate our results with experiments on a variety of random graph models.Comment: Full Version of a version which appeared in AIRweb 200

The Imposter Among Us: How Imposter Syndrome is Fueled by Diversity Discourses

In this paper, first presented at the 2023 LACUNY Institute, the author discusses definitions of imposter syndrome and how imposter syndrome fits within the diversity model. The diversity model, as used in this paper, emerges from an oversimplified framing of racial inequity as a problem that is solved by simply hiring diverse bodies to appear inclusive. In conjunction with the proliferation of imposter syndrome in post-secondary institutions, the ongoing phenomenon of imposter syndrome among librarians and academics reveals an underlying systemic problem rather than individual shortcomings. Workplace discomfort in post-secondary institutions is too easily brushed off as imposter syndrome, without any critical self-reflection on the underlying causes that contribute to such high rates of individuals experiencing the syndrome. While the pathological “diagnosis” of imposter syndrome is unproductive in combating the underlying systemic problems that contribute to such experiences, there are two distinct uses of imposter syndrome in our lexicon: imposter-syndrome-as-pathology and the affective experience of imposter syndrome. In critiquing imposter-syndrome-as-pathology, this paper highlights how the diversity model pushes racialized information professionals to experience imposter syndrome

Validation of schizotypal measures: can they be used cross-culturally?

This thesis validated schizotypal measures in clinical and non-clinical populations, and answered whether these scales can be used cross-culturally. The result pointed to the need of being mindful of exisiting differences in cultural applications

Main ecological drivers of woody plant species richness recovery in secondary forests in China

Identifying drivers behind biodiversity recovery is critical to promote efficient ecological restoration. Yet to date, for secondary forests in China there is a considerable uncertainty concerning the ecological drivers that affect plant diversity recovery. Following up on a previous published meta-analysis on the patterns of species recovery across the country, here we further incorporate data on the logging history, climate, forest landscape and forest attribute to conduct a nationwide analysis of the main drivers influencing the recovery of woody plant species richness in secondary forests. Results showed that regional species pool exerted a positive effect on the recovery ratio of species richness and this effect was stronger in selective cutting forests than that in clear cutting forests. We also found that temperature had a negative effect, and the shape complexity of forest patches as well as the percentage of forest cover in the landscape had positive effects on the recovery ratio of species richness. Our study provides basic information on recovery and resilience analyses of secondary forests in China

PhiC31 integrase induces a DNA damage response and chromosomal rearrangements in human adult fibroblasts

<p>Abstract</p> <p>Background</p> <p>PhiC31 integrase facilitates efficient integration of transgenes into human and mouse genomes and is considered for clinical gene therapy. However recent studies have shown that the enzyme can induce various chromosomal abnormalities in primary human embryonic cells and mammalian cell lines. The mechanisms involved are unknown, but it has been proposed that PhiC31 attachment sites in the host genome recombine leading to chromosomal translocations.</p> <p>Results</p> <p>We have studied possible effects of the PhiC31 integrase expression in human adult fibroblasts by karyotyping. All control cells were cytogenetically normal, whereas cells expressing PhiC31 integrase show chromosomal abnormalities confirming our previous results using primary embryonic fibroblasts. In order to study the early mechanisms involved we measured H2AX phosphorylation – a primary event in the response to DNA double-strand-breaks. Transient transfection with PhiC31 integrase encoding plasmids lead to an elevated number of cells positive for H2AX phosphorylation detected by immunofluorescence. Western blot analysis confirmed the upregulated H2AX phosphorylation, whereas markers for apoptosis as well as p53 and p21 were not induced. Cells transfected with plasmids encoding the Sleeping Beauty transposase remained cytogenetically normal, and in these cells less upregulation of H2AX phosphorylation could be detected.</p> <p>Conclusion</p> <p>In primary human fibroblasts expression of PhiC31 integrase leads to a DNA damage response and chromosomal aberrations.</p