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A NEW DIRECTION FOR SCIENCE AND VALUES Thanks to
No full textAbstract The controversy over the old ideal of "value-free science" has cooled significantly over the past decade. Many philosophers of science now agree that even ethical and political values may play a substantial role in all aspects of scientific inquiry. Consequently, in the last few years, work in science and values has become more specific: Which values may influence science, and in which ways? Or, how do we distinguish illegitimate from illegitimate kinds of influence? In this paper, I argue that this problem requires philosophers of science to take a new direction. I present two case studies in the influence of values on scientific inquiry: feminist values in archaeology and commercial values in pharmaceutical research. I offer a preliminary assessment of these cases, that the influence of values was legitimate in the feminist case, but not in the pharmaceutical case. I then turn to three major approaches to distinguish legitimate from illegitimate influences of values, including the distinction between epistemic and non-epistemic values and Heather Douglas' distinction between direct and indirect roles for values. I argue that none of these three approaches gives an adequate analysis of the two cases. In the concluding section, I briefly sketch my own approach, which draws more heavily on ethics than the others, and is more promising as a solution to the current problem. This is the new direction in which I think science and values should move
Revista Brasileira de Parasitologia Veterinária Molecular and parasitological detection of Leishmania spp. in dogs caught in Palmas
No full textAbstract This study evaluated occurrences of Leishmania infantum in dogs in the municipality of Palmas, Tocantins, comparing diagnostic data obtained using the polymerase chain reaction (PCR) and parasitological diagnosis. Blood samples and lymph node aspirates were collected from 63 dogs of males and females and various ages and races, with or without owners, between August 2009 and June 2010. Slides containing smears of lymph node aspirates were stained with Giemsa stained. In PCR, the 145 bp target sequence of the LT1 fragment, located in the Leishmania donovani kDNA minicircle was detected using the RV1 and RV2 oligonucleotide primers. The chi-square test revealed that there was a significant relationship between the symptoms and dogs that were positive for visceral leishmaniasis (VL). The parasitological investigation showed concordance of 66.7% with PCR on blood and 84.1% with PCR on lymph node aspirate. In addition to these tests, evaluations of the diagnoses in parallel and in series were conducted, which showed concordances with the parasitological test of 76.2% and 74.6%, respectively. The results make it possible to suggest that PCR on lymph nodes should be used in evaluating large populations (surveys) and that the parasitological test should be used for initial clinical evaluations in veterinary consultation offices. Keywords: PCR, blood, lymph node aspirate, parasite, diagnosis. Resumo Avaliou-se a ocorrência de Leishmania infantum em cães do município de Palmas-TO, comparando dados diagnósticos obtidos pela Reação em Cadeia da Polimerase (PCR) e pelo diagnóstico parasitológico. Foram coletadas amostras de sangue e de aspirado de linfonodo de 63 cães machos e fêmeas, várias idades e raças, domiciliares ou não de agosto de 2009 a junho de 2010. As lâminas contendo esfregaço dos aspirados de linfonodos foram coradas pelo corante Giemsa. Na PCR, a sequência alvo de 145 pb do fragmento LT1, situado no minicírculo do kDNA do grupo Leishmania donovani, foi detectada através dos oligonucleotídeos iniciadores RV1 e RV2. O teste χ 2 (Qui-quadrado), demonstrou haver relação significativa entre a sintomatologia e a positividade dos cães para Leishmaniose Visceral (LV). O exame parasitológico mostrou uma concordância de 66,7% com a PCR em sangue e 84,1% com a PCR de aspirado de linfonodo. Além destas análises, houve a avaliação dos diagnósticos em paralelo e em série, onde as concordâncias com o exame parasitológico foram de 76,2% e 74,6%, respectivamente. Os resultados permitem sugerir a utilização da PCR de linfonodos na avaliação de grandes populações (inquéritos), e o exame parasitológico para a avaliação clínica inicial em consultórios veterinários. Palavras-chaves: PCR, sangue, aspirado de linfonodos, parasita, diagnóstico
2 Weed Management Challenges in Fairtrade Banana Farm Systems in the Windward Islands of the Caribbean
Get PDFOn the Robust Control of Continuous-time Markov Jump Linear Systems Subject to Block-diagonal Uncertainty
Get PDFAbstract-This paper addresses the robust H 2 2 2 and H ∞ ∞ ∞ control problems for continuous-time Markov jump linear systems subjected to block-diagonal perturbations. The proposed approach features the introduction of more powerful scaling techniques than the ones available in the current Markov jump linear systems literature. We further propose uncertaintydependent LMI design methods to treat the case of polytopic uncertainty on the transition rates of the Markov process. In the end of the paper, an application of the main results is illustrated with a numerical example
Communicating Process Architectures
Get PDFAbstract. In this paper we consider a refinement of the concept of mobile processes in a process oriented language. More specifically, we investigate the possibility of allowing resumption of suspended mobile processes with different interfaces. This is a refinement of the approach taken currently in languages like occam-π. The goal of this research is to implement varying resumption interfaces in ProcessJ, a process oriented language being developed at UNLV
Mineral Resources of the North Fork of the Little Humboldt River Wilderness Study Area, Humboldt County, Nevada DEPARTMENT OF THE INTERIOR DONALD PAUL MODEL, Secretary U.S. GEOLOGICAL SURVEY Library of Congress Cataloging-in-Publication Data
No full textMetabolic network adaptations in cancer as targets for novel therapies
Get PDFAbstract Metabolite concentrations and fluxes are the system variables that characterize metabolism. The systematic study of metabolite profiles is known as metabolomics; however, knowledge of the complete set of metabolites may not be enough to predict distinct phenotypes. A complete understanding of metabolic processes requires detailed knowledge of enzyme-controlled intracellular fluxes. These can be estimated through quantitative measurements of metabolites at different times or by analysing the stable isotope patterns obtained after incubation with labelled substrates. We have identified distinct intracellular fluxes associated with metabolic adaptations accompanying cancer. The maintenance of an imbalance between fluxes for the oxidative and non-oxidative PPP (pentose phosphate pathway) has been shown to be critical for angiogenesis and cancer cell survival. Mouse NIH 3T3 cells transformed by different mutated K-ras oncogenes have differential routing of glucose to anaerobic glycolysis, the PPP and the Krebs cycle. These results indicate that knowledge of metabolic fingerprints associated with an altered genetic profile could be exploited in the rational design of new therapies. We conclude that the understanding of the multifactorial nature of metabolic adaptations in cancer may open new ways to develop novel multi-hit antitumoral therapies. The systematic study of the metabolism Current high-throughput technologies are applied to examine the whole components of a cell. However, understanding the crucial cellular events such as differentiation, cell-cycle progression or apoptosis requires detailed knowledge not only of the components, but also of how they interact in systems [1]. Moreover, high-throughput technologies cannot be designed for the analysis of all cellular components. In the case of the genome, the physicochemical homogeneity of its components has facilitated its analysis, resulting in the spectacular advance of genomics. This homogeneity contrasts with the high heterogeneity that characterizes metabolism. The systematic study of the metabolic compounds is known as metabolomics, where the metabolome is defined as the set of all low-molecular-mass compounds present in a biological system [2]. The large number of different metabolites, differences in their relative concentrations and variability in their physicochemical properties (polarity, hydrophobicity, molecular mass or chemical stability) require the application of different technologies and a huge range of experimental conditions. Thus specific methodologies are Key words: antitumoral therapy, cancer, flux analysis, metabolomics, systems biology, tumour metabolism. Abbreviations used: G6PDH, glucose-6-phosphate dehydrogenase; HIF-1, hypoxia-inducible transcription factor-1; LDH, lactacte dehydrogenase; PDH, pyruvate dehydrogenase; PK, pyruvate kinase; PPP, pentose phosphate pathway; ROS, reactive oxygen species; TKT, transketolase; TKTL1, TKT-like-1. 1 To whom correspondence should be addressed (email [email protected]). being developed for the various groups of metabolites, such as lipids (lipidomics) or sugars (glycomics). Interestingly, such methods could be applied to the study of the metabolome and its importance in the development and progression of tumours [3]. Differential flux distribution Metabolite concentrations and fluxes are the interdependent system variables that characterize metabolism. A comprehensive characterization of metabolic operation can be obtained from quantitative knowledge of intracellular fluxes, which are intimately associated with the corresponding enzyme activities. Moreover, the metabolic profile of a specific cell represents the integrated end point of many growth-signalling events, and it consists of the simultaneous assessment of fluxes in major metabolic pathways under various physiological conditions, growth phases and substrate environments [4]. Quantitative measurements of metabolites at different times are applied for the measurement of metabolic fluxes. In particular, tracer-based metabolomics is a useful approach for the analysis of the propagation of labelled molecules to metabolic products by NMR or chromatography coupled to MS [GC-MS and LC (liquid chromatography)-MS]. Thus the analysis of the stable isotope patterns obtained after incubation with labelled substrates is applied for the measurement of the fluxes throughout the steps of the metabolic pathways. For example, labelling with [1,2-13 C 2 ]glucose and the subsequent
