92,647 research outputs found

    Internal Perspectivalism: The Solution to Generality Problems About Proper Function and Natural Norms

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    In this paper, I argue that what counts as the proper function of a trait is a matter of the de facto perspective that the biological system, itself, possesses on what counts as proper functioning for that trait. Unlike non-perspectival accounts, internal perspectivalism does not succumb to generality problems. But unlike external perspectivalism, internal perspectivalism can provide a fully naturalistic, mind-independent grounding of proper function and natural norms. The attribution of perspectives to biological systems is intended to be neither metaphorical nor anthropomorphic: I do not mean to imply that such systems thereby must possess agency, cognition, intentions, concepts, or mental or psychological states. Instead, such systems provide the grounding for norms of performance when they internally enforce their own standard of (i.e., their own perspective on) what constitutes proper functioning or malfunctioning. By operating with a fixed, determinate level of generality, such systems provide the basis for an account of proper function that is immune to generality problems

    Método de la microgota: usado con agar cromogénico es un procedimiento útil para el monitoreo sanitario en acuicultura

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    Indexación: Web of Science, Scielo.The microdot method is a downscaling methodology of traditional tenfold serial dilution procedure used in microbiology. The microdot method uses 100 mu L for serial dilution and count colonies in a spot of 10 mu L. In this study we counted colonies directly in a chromogenic agar plate to determine, at the same time, the presence and cell concentration of target bacteria required for sanitary monitoring of Chilean export fishery products. Due to among importers countries the most concerning bacteria included in sanitary monitoring are Escherichia coli, Listeria monocytogenes and Staphylococcus aureus, we used the chromogenic agar; CHROMagar ECC, CHROMagar Listeria and Baird Parker agar, respectively. The results shows no differences between quantitative results obtained with microdot and traditional method during the quantification of a culture of Escherichia coli (1.5 L). The sensitivity and specificity of the microdot method in association with each chromogenic agar was demonstrated in vitro with reference strains. In addition, the usefulness in sanitary monitoring of aquaculture procedures was evaluated in Artemia salina tanks. This method did not detected sanitary problems in surface water. Although other colonies grown in the chromogenic agar plate, their morphological and chromogenic properties not correspond to Escherichia coli, Listeria monocytogenes and Staphylococcus aureus, being identified as Salmonella enterica subsp. enterica, Microbacterium sp., Bacillus sp. and Staphylococcus pasteuri by 16S rRNA gene sequence analysis. Hence, we propose the microdot chromogenic method as a low cost, specific and reliable procedure for sanitary monitoring of aquaculture procedures.El método de la microgota es una versión a menor escala del procedimiento tradicional de dilución en serie en base diez utilizados en microbiología. El método realiza diluciones en 100 µL y cuenta colonias crecidas en una gota de 10 µL. En este estudio se cuentan colonias directamente en placas cromogénicas para determinar densidad celular y presencia de bacterias requeridas en vigilancia sanitaria de productos pesqueros chilenos de exportación. Entre los requisitos de países importadores, la vigilancia sanitaria involucra frecuentemente a Escherichia coli, Listeria monocytogenes y Staphylococcus aureus, por lo que se utilizan los agares cromogénicos; CHROMagar ECC, CHROMagar Listeria y agar Baird Parker para su identificación. La comparación entre el método de microgota y el método tradicional no muestra diferencias al evaluar un cultivo de Escherichia coli (1,5 L). La sensibilidad y especificidad del método de microgota junto a cada agar cromogénico se demostró in vitro con cepas de referencia. Además, en estanques de Artemia salina se evaluó la utilidad de este método para el monitoreo sanitario. Este método no mostró problemas sanitarios en aguas superficiales, aunque otras colonias crecieron en la placa de agar cromogénico. Sus propiedades morfológicas y cromogénicas no corresponden a Escherichia coli, Listeria monocytogenes y Staphylococcus aureus, siendo identificadas según el análisis de la secuencia del gen 16S rRNA como Salmonella enterica subsp. enterica, Microbacterium sp., Bacillus sp. y Staphylococcus pasteuri. Por lo tanto, se propone el método de microgota cromogénico como un procedimiento de bajo costo, específico y fiable para el monitoreo sanitario en acuicultura.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-560X2016000400009&lng=e

    Cooperation among strangers: an experiment with indefinite interaction

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    We study the emergence of norms of cooperation in experimental economies populated by strangers interacting indefinitely and lacking formal enforcement institutions. In all treatments the efficient outcome is sustainable as an equilibrium. We address the following questions: can these economies achieve full efficiency? Which institutions for monitoring and enforcement promote cooperation? Finally, what classes of strategies are employed to achieve high efficiency? We find that, first, cooperation can be sustained even in anonymous settings; second, some type of monitoring and punishment institutions significantly promote cooperation; and, third, subjects dislike indiscriminate strategies and prefer selective strategies.experiments, repeated games, cooperation, equilibrium selection, prisoners’ dilemma, random matching

    Development Of Novel Radiotracers For Pet Imaging Of Hdac-Mediated Epigenetic Regulation

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    Over the past two decades, epigenetic regulation has become a rapidly growing, highly innovative and influential field of biology and medicine. Protein acetylation and deacetylation, two key epigenetic regulatory mechanisms, are mediated by histone acetylase transferases (HATs) and histone deacetylases (HDACs), respectively. To date, the vast majority of studies on epigenetic regulation have been conducted in cell cultures and tissue samples using conventional methodologies of molecular and cellular biology, which contain inherent limitations for monitoring therapy and disease. Therefore, there is a growing need for novel, advanced methodologies that allow for non-invasive detection and monitoring of HDAC–mediated epigenetic regulatory processes in different organs and tissues. One such methodology is molecular imaging with positron emission tomography (PET), which allows for non-invasive visualization and quantification of spatial and temporal dynamics of expression-activity of various receptors and enzymes in different organs and tissues in norm and disease. The availability of selective substrates to various classes and isoforms of HDACs would enable the development of radiolabeled imaging agents for non-invasive in vivo PET imaging. Therefore, the aim of this work is to develop class- and/or isoform-selective radiolabeled substrates of HDACs, with particular emphasis on class III (sirtuins, SIRTs). Herein, HDAC class IIa, SIRT1 and SIRT2-selective radiotracers have been developed and validated through in vitro and in vivo characterization. Two of these tracers, 18F-TFAHA for HDAC class IIa and and 2-[18F]PhAHA for SIRT1, have also been validated in a disease model demonstrating their utility in understanding epigenetic regulation in an aggressive form of brain cancer. The development of these targeted imaging agents may help develop new therapies for disease as well as methodologies for monitoring treatment effectiveness and disease progression
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