892 research outputs found
Identifying Current and Missing Knowledge in the Control of Pyrethroid-Resistant Triatoma Infestans, Vector of Chagas Disease
Triatomines are blood-sucking bugs that occur mainly in Latin America. They are vectors of Trypanosoma cruzi, the parasite that causes Chagas disease. Chemical control of Chagas disease´s vectors by using pyrethroid insecticides has been highly successful for the elimination of domestic infestation and consequently the reduction of the vector transmission. However, at the beginning of the 2000s a decrease in the effectiveness of the chemical control of triatomines was detected in several areas from Argentina and Bolivia, particularly in the Gran Chaco eco-region. During the last 15 years, several studies demonstrated the evolution of insecticide resistance in Triatoma infestans and established the presence of different toxicological profiles, the autosomal inherence of resistance, the biological costs of deltamethrin resistance, the expression of deltamethrin resistance thorough the embryonic development, and the main mechanisms of resistance (target-site insensitivity and metabolic detoxification of insecticides). The emergence of pyrethroid resistance coupled with the usual difficulties in sustaining adequate rates of insecticide applications emphasize the need of incorporating other tools for integrated vector and disease control, such as the proposal of the organo-phosphorus insecticide fenitrothion as an alternative chemical strategy for the management of the resistance because it was effective against pyrethroid-resistant populations in laboratory and semi-field trials. New studies on the current situation of presence and spread of resistant populations of triatomines and the acceptance of the use of alternative insecticides are critical requirements in the implementation of strategies for the management of resistance and for the rational design of campaigns oriented to reducing the vector transmission of Chagas’ disease.Fil: Roca Acevedo, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Picollo, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentin
Amperometric detection of quantal catecholamine secretion from individual cells by an ion beam microfabricated single crystalline diamond biosensor
It is shown that buried graphitic channels fabricated in monocrystalline diamond by selective damage induced by focused MeV ions, can be considered an effective alternative to the commonly used carbon-fibers to detect the catecholamine release from cells as individual secretory granules discharge their contents during the process of quantal exocytosis. Quantal secretory responses have been measured from stimulated chromaffin cells, which were positioned on the graphitic microelectrode, polarized to +800 mV. Sequences of amperometric spikes started after cell stimulation with the KCl solution, with amplitudes well above the background noise within the range of 8–180 pA and comparable with signals obtained by conventional carbon fiber electrodes
Minimalism, Reference, and Paradoxes
The aim of this paper is to provide a minimalist axiomatic theory of truth based on the notion of reference. To do this, we first give sound and arithmetically simple notions of reference, self-reference, and well-foundedness for the language of first-order arithmetic extended with a truth predicate; a task that has been so far elusive in the literature. Then, we use the new notions to restrict the T-schema to sentences that exhibit "safe" reference patterns, confirming the widely accepted but never worked out idea that paradoxes can be characterised in terms of their underlying reference patterns. This results in a strong, ω-consistent, and well-motivated system of disquotational truth, as required by minimalism
Reference in Arithmetic
Self-reference has played a prominent role in the development of metamathematics in the past century, starting with Gödel’s first incompleteness theorem. Given the nature of this and other results in the area, the informal understanding of self-reference in arithmetic has sufficed so far. Recently, however, it has been argued that for other related issues in metamathematics and philosophical logic a precise notion of self-reference and, more generally, reference is actually required. These notions have been so far elusive and are surrounded by an aura of scepticism that has kept most philosophers away. In this paper I suggest we shouldn’t give up all hope. First, I introduce the reader to these issues. Second, I discuss the conditions a good notion of reference in arithmetic must satisfy. Accordingly, I then introduce adequate notions of reference for the language of first-order arithmetic, which I show to be fruitful for addressing the aforementioned issues in metamathematics
Reference in Arithmetic
Self-reference has played a prominent role in the development of metamathematics in the past century, starting with Gödel’s first incompleteness theorem. Given the nature of this and other results in the area, the informal understanding of self-reference in arithmetic has sufficed so far. Recently, however, it has been argued that for other related issues in metamathematics and philosophical logic a precise notion of self-reference and, more generally, reference is actually required. These notions have been so far elusive and are surrounded by an aura of scepticism that has kept most philosophers away. In this paper I suggest we shouldn’t give up all hope. First, I introduce the reader to these issues. Second, I discuss the conditions a good notion of reference in arithmetic must satisfy. Accordingly, I then introduce adequate notions of reference for the language of first-order arithmetic, which I show to be fruitful for addressing the aforementioned issues in metamathematics
The Old-Fashioned Yablo Paradox
The yablo Paradox’ main interest lies on its prima facie non-circular character, which many have doubted, specially when formulated in an extension of the language of first-order arithmetic. Particularly, Priest (1997) and Cook (2006, forthcoming) provided contentious arguments in favor of circularity. my aims in this note are (i) to show that the notion of circularity involved in the debate so far is defective, (ii) to provide a new sound and useful partial notion of circularity and (iii) to show there is a non-circular formulation of the list in an extension of the language of firstorder arithmetic according to the new notion.El interés principal de la Paradoja de Yablo yace en su carácter prima facie no circular, el cual ha sido puesto en duda especialmente con respecto a la formulación de la paradoja en una extensión del lenguaje de la aritmética de primer orden. Particularmente, Priest (1997) y Cook (2006, en prensa) formularon argumentos contenciosos a favor de la circularidad. los objetivos de esta nota son (i) señalar que la noción de circularidad utilizada hasta el momento en el debate es defectuosa, (ii) ofrecer una nueva noción parcial adecuada y útil de circularidad y (iii) mostrar que existe una formulación no circular de la lista en una extensión del lenguaje de la aritmética de primer orden de acuerdo con la nueva noció
Yablo's Paradox in Second-Order Languages: Consistency and Unsatisfiability
Stephen Yablo [23,24] introduces a new informal paradox, constituted by an infinite list of semi-formalized sentences. It has been shown that, formalized in a first-order language, Yablo's piece of reasoning is invalid, for it is impossible to derive falsum from the sequence, due mainly to the Compactness Theorem. This result casts doubts on the paradoxical character of the list of sentences. After identifying two usual senses in which an expression or set of expressions is said to be paradoxical, since second-order languages are not compact, I study the paradoxicality of Yablo's list within these languages. While non-paradoxical in the first sense, the second-order version of the list is a paradox in our second sense. I conclude that this suffices for regarding Yablo's original list as paradoxical and his informal argument as valid.Fil: Picollo, Lavinia María. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Studio mediante spettroscopia in riflettanza non invasiva dei pigmenti utilizzati dal pittore Giovan Battista Naldini nel dipinto La natività, Chiesa di Santa Maria Novella, Firenze
Le misure FORS (Fig. 1), oggetto della presente relazione tecnico-scientifica, sono state effettuate il 15 dicembre 2008 presso lo Studio di Restauro Vervat sul dipinto di Giovan Battista Naldini “La Natività” del 1573 appartenente alla Chiesa di Santa Maria Novella, Firenze. La tecnica impiegata per la caratterizzazione del materiale pittorico si basa sull’analisi di spettri di riflettanza acquisiti in maniera non invasiva
Lightning Talk #4 (5 min): Our Own Labels: LGBT2QIA+ Representation in Catalogue Records
Abstract
Continuing to build on relationships formed between Out On The Shelves and the University of British Columbia School of Information, we are seeking to explore radical possibilities for cataloguing queer works for queer audiences. As an independent, volunteer-run library, Out On The Shelves has opportunities to depart from traditional cataloguing practices and experiment with approaches impossible or undesirable in other settings. In this lightning talk, we outline a proposed creator consultation project to explore how creator and character identities might be represented in item records. Out On the Shelves prioritizes the “the voices of LGBT2QIA+ individuals writing, creating, and reflecting their own experiences” and at the heart of this project is an understanding that users of the library often seek books by or featuring people like them. However, there are inherent limitations and dangers of building this information into a traditional library cataloguing process. We engage with broad concerns in queer theory and social justice librarianship to reconsider the item record and the controlled vocabulary—is a creator’s identity constant or can it shift over time and in relation to different works? whose place is it to assert a creator’s identity and decide how it is phrased? how can control of terms and term relationships respect a creator’s expressions while meeting the discoverability and access needs of users? This spring, we piloted an interview protocol that seeks to give living creators of works at Out On The Shelves informed choices on how their works are described in the library catalogue, with a focus on identity terms for themselves and the characters in their works. Our next steps are to refine this interview approach and to engage with creators of different, overlapping identities and different types of works in the collection. With a broad set of creator perspectives, we will turn to re-cataloguing their works and will develop channels for living creators to continue to have input into the language and representation of their works in the library’s descriptive systems. This collaborative work between library workers and creators will lead to further work reconciling the outcomes of this process with the needs of users and the representation of the rest of the collection. We will discuss the challenges (and joy) of this approach and welcome discussion of how to move forward and queer the cataloguing process
Higher-Order Logic and Disquotational Truth
Truth predicates are widely believed to be capable of serving a certain logical or quasi-logical function. There is little consensus, however, on the exact nature of this function. We offer a series of formal results in support of the thesis that disquotational truth is a device to simulate higher-order resources in a first-order setting. More specifically, we show that any theory formulated in a higher-order language can be naturally and conservatively interpreted in a first-order theory with a disquotational truth or truth-of predicate. In the first part of the paper we focus on the relation between truth and full impredicative sentential quantification. The second part is devoted to the relation between truth-of and full impredicative predicate quantification
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