Computing discriminating and generic words

International audienceWe study the following three problems of computing generic or discriminating words for a given collection of documents. Given a pattern P and a threshold d, we want to report (i) all longest extensions of P which occur in at least d documents, (ii) all shortest extensions of P which occur in less than d documents, and (iii) all shortest extensions of P which occur only in d selected documents. For these problems, we propose efficient algorithms based on suffix trees and using advanced data structure techniques. For problem (i), we propose an optimal solution with constant running time per output word

Ultrafast spectroscopy and computational study of the photochemistry of diphenylphosphoryl azide: direct spectroscopic observation of a singlet phosphorylnitrene

The photochemistry of diphenylphosphoryl azide was studied by femtosecond transient absorption spectroscopy, by chemical analysis of light-induced reaction products, and by RI-CC2/TZVP and TD-B3LYP/TZVP computational methods. Theoretical methods predicted two possible mechanisms for singlet diphenylphosphorylnitrene formation from the photoexcited phosphoryl azide. (i) Energy transfer from the (π,π*) singlet excited state, localized on a phenyl ring, to the azide moiety, thereby leading to the formation of the singlet excited azide, which subsequently loses molecular nitrogen to form the singlet diphenylphosphorylnitrene. (ii) Direct irradiation of the azide moiety to form an excited singlet state of the azide, which in turn loses molecular nitrogen to form the singlet diphenylphosphorylnitrene. Two transient species were observed upon ultrafast photolysis (260 nm) of diphenylphosphoryl azide. The first transient absorption, centered at 430 nm (lifetime (τ) 28 ps), was assigned to a (π,π*) singlet S1 excited state localized on a phenyl ring, and the second transient observed at 525 nm (τ 480 ps) was assigned to singlet diphenylphosphorylnitrene. Experimental and computational results obtained from the study of diphenyl phosphoramidate, along with the results obtained with diphenylphosphoryl azide, supported the mechanism of energy transfer from the singlet excited phenyl ring to the azide moiety, followed by nitrogen extrusion to form the singlet phosphorylnitrene. Ultrafast time-resolved studies performed on diphenylphosphoryl azide with the singlet nitrene quencher, tris(trimethylsilyl)silane, confirmed the spectroscopic assignment of singlet diphenylphosphorylnitrene to the 525 nm absorption band

Green synthesis of copper oxide nanoparticles using Amaranthus dubius leaf extract for sensor and photocatalytic applications

Copper oxide nanoparticles (CuO NPs) were produced through an environmentally friendly green synthesis. The characteristics of these green synthesized CuO NPs, including their structural, optical, morphological, and electrochemical properties, were examined using various characterization techniques. X-ray diffraction analysis revealed that the CuO NPs have a monoclinic structure with a C2/c space group. Electrochemical detection of glucose was carried out using cyclic voltammetry. The green synthesized CuO NPs exhibited excellent catalytic properties for both electrochemical sensing and photocatalysis. Significantly, these CuO NPs exhibited excellent selectivity and sensitivity in glucose detection, with a sensitivity of 370 μA mM−1 cm−2 and a detection limit of 1.0 μM. Furthermore, the CuO NPs demonstrated a substantial 84 % degradation of dyes within 150 min. These results underscore the potential of the green synthesized CuO NPs as a promising material for applications in both sensing and dye degradation

Clustering-Based Bidding Languages for Sponsored Search

Sponsored search auctions provide a marketplace where advertisers can bid for millions of advertising opportunities to promote their products. The main difficulty facing the advertisers in this market is the complexity of picking and evaluating keywords and phrases to bid on. This is due to the sheer number of possible keywords that the advertisers can bid on, and leads to inefficiencies in the market such as lack of coverage for “rare ” keywords. Approaches such as broad matching have been proposed to alleviate this problem. However, as we will observe in this paper, broad matching has undesirable economic properties (such as the non-existence of equilibria) that can make it hard for an advertiser to determine how much to bid for a broad-matched keyword. The main contribution of this paper is to introduce a bidding language for sponsored search auctions based on broad-matching keywords to non-overlapping clusters that greatly simplifies the bidding problem for the advertisers. We investigate the algorithmic problem of computing the optimal clustering given a set of estimated values and give an approximation algorithm for this problem. Furthermore, we present experimental results using real advertisers ’ data that show that it is possible to extract close to the optimal social welfare with a number of clusters considerably smaller than the number of keywords. This demonstrates the applicability of the clustering scheme and our algorithm in practice.

Abstract A108: Improving communication and management following a positive home HPV self-sampling kit result

Abstract Background: Over 14,000 cervical cancers are diagnosed annually in the U.S. In 2019, ~30% of individuals with a cervix were under-screened based on current guidelines. Previous studies established feasibility of mailed self-sampling high-risk HPV test kits to improve screening adherence. Qualitative findings from our HOME trial found unmet information needs and anxiety among patients with a positive kit result. We designed the STEP trial to test optimized implementation strategies for educating patients about screening when offering the kit to patients due/overdue for screening, and when reporting results. Purpose: To evaluate acceptability of the implementation strategies, we interviewed individuals after receiving a positive kit result about the result communication processes and their information needs. Methods: The STEP trial added a centralized licensed practical nurse to communicate about and arrange scheduling for all patients with positive kit results, and provided an educational pamphlet to explain the purpose of HPV testing (especially difference to Pap testing) and how latent infections can reactivate. Telephone interviews were conducted from December 2021 to March 2022 with 29 patients (56% of invited) who had a positive kit result. Interview guide asked about reaction to the kit, results communication, patient-provider interactions, and follow-up visit experiences; and included a survey regarding attitudes toward the kit. Five coders analyzed interview transcripts using iterative content analysis; 12 transcripts were double-coded. Codes were organized into node reports to identify overarching themes. Results: Of 29 participants, most (65.5%) were non-Hispanic White and the average age was 47.5 years (SD=11.2). Participants appreciated the convenience of the kit, though a few worried about the accuracy of self-sampling test results, especially compared to screening performed by a provider. While surprised by the positive kit result, all reported feeling reassured after talking with the nurse and understood next steps in the diagnosis and management process, although some reported still wanting to check with their primary care provider about the test findings. Though an educational pamphlet was provided with the home HPV kit, most participants did not recall receiving it or using it to understand their kit results. After reflecting on home kit versus in-clinic screening, most (69%) preferred using the kit on their own to provider-collected screening. All (100%) agreed that the kit instructions were easy to understand, however 90% were sure that they had sampled the right place, and 86% believed that the home test results were correct. Discussion: Unlike the prior HOME trial, there was less negative affect expressed by patients after receiving results. This suggests patients received the information needed to continue with the screening process and supports the value of a centralized nurse. Providing educational materials at multiple timepoints may further improve results communication in the future. Citation Format: Meera Muthukrishnan, Jasmin A. Tiro, Kris Hansen, John Lin, Caitlin Dorsey, Hongyuan Gao, Catherine Troja, Melissa Anderson, Richard Meenan, Beverly B. Green, Diana S.M. Buist, Rachel Winer. Improving communication and management following a positive home HPV self-sampling kit result [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr A108.</jats:p