1,069 research outputs found

    Protein structure analysis through Hough Transform and Range Tree

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    The Generalized Hough Transform (GHT) allows to recognize general patterns once defined a model to be recognized, a reference point (RP) rigid with the model, and a mapping rule. This rule establishes the contributions in the parameters space; this space, generally speaking, is given by the parameters of a rigid motion leading to overlap a model item with an equal item detected on the unknown pattern. In this paper we introduce the GHT applied to motifs, domains and entire proteins retrieval into a protein data base. The spatial attitude of a single protein secondary structure (SS) constitutes the item supporting the contributions. If the unknown pattern contains a block of N SS of the model to be recognized, the N corresponding votes will have a common point, so accumulating N contributions. An analysis of the neighborhoods around the areas with high contributions density is necessary. It is not sufficient and often inaccurate to limit the analysis to the peaks even if the number of contribution is closed to the expected one. Both convenient data structures for effectively operating in the neighborhoods (a range tree data structure) and suitable decision criteria have been introduced. Preliminary results of comparative analysis are given

    Exploring the meanings of community multimedia centers in Mozambique : a social representations perspective

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    This article presents extensive research conducted in Mozambique that aims to deeply understand how different social groups understand community multimedia centers (CMCs), which are structures combining a community radio and a telecenter. The social representations theory was adopted to interpret narratives of 231 interviewees from 10 Mozambican provinces. Interviewees included representatives of initiating agencies, local staff members, CMC users (both the radio and telecenter components), users of only the community radio, and community members not using the CMCs. Following the analysis of transcribed interviews, six main clusters were identified, each of them shedding light on a specific understanding of a CMC. These are discussed according to a set of sociodemographic variables. This study suggests that the social representations theory is a valuable framework to provide an integrated view of ICT4D interventions by giving a voice to local perspectives without overlooking the initiating agencies’ expectations

    A random-effects hurdle model for predicting bycatch of endangered marine species

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    Understanding and reducing the incidence of accidental bycatch, particularly for vulnerable species such as sharks, is a major challenge for contemporary fisheries management worldwide. Bycatch data, most often collected by at-sea observers during fishing trips, are clustered by trip and/or vessel and typically involve a large number of zero counts and very few positive counts. Though hurdle models are very popular for count data with excess zeros, models for clustered forms have received far less attention. Here we present a novel random-effects hurdle model for bycatch data that makes available accurate estimates of bycatch probabilities as well as other clusterspecific targets. These are essential for informing conservation and management decisions as well as for identifying bycatch hotspots, often considered the first step in attempting to protect endangered marine species. We validate our methodology through simulation and use it to analyze bycatch data on critically endangered hammerhead sharks from the U.S. National Marine Fisheries Service Pelagic Observer Program

    Does ozonation enhance activated carbon adsorption of PFAS in textile wastewater?

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    Per- and polyfluoroalkyl substances (PFAS) are used in numerous industrial applications, such as in textile manufacturing, because of their special chemical properties. To avoid PFAS spread in the environment, removal strategies need to be implemented at the wastewater treatment plants (WWTP) to reduce their environmental risk on receiving water bodies. The fate of 14 PFAS in a full-scale WWTP treating textile and civil wastewater (WW) was investigated. The addition of an adsorption step before or after the ozonation process was studied through adsorption isotherms tested on the WW collected before and after the full-scale ozonation step. Ozonation is not aimed at PFAS removing, but it lowers organic matter competition towards long-chain PFAS in the following adsorption step. The removal of UVA254 seems to be a good proxy variable for PFAS adsorption, with relationships not dependent on the presence of ozonation step

    Adsorption on activated carbon for PFAS removal: should we act at the source or before the discharge into the environment?

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    Per- and polyfluoroalkyl substances (PFAS), used in several industrial applications, such as textile production, are gaining increasing concern due to their spread in the environment, their stability and eco-toxicity. To avoid PFAS spread in the environment, removal strategies need to be implemented at both industrial and municipal wastewater treatment plants (WWTP). This study presents a case study in a textile district in northern Italy where PFAS removal in wastewater (WW) through adsorption on activated carbon was tested at lab and pilot-scale at different points of the system (textile companies and municipal WW treatment plant). This lab-testing was proved to be useful to identify where to apply such process in the system and to optimize process configuration and operating conditions
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