553 research outputs found
Grounding knowledge and normative valuation in agent-based action and scientific commitment
Philosophical investigation in synthetic biology has focused on the knowledge-seeking questions pursued, the kind of engineering techniques used, and on the ethical impact of the products produced. However, little work has been done to investigate the processes by which these epistemological, metaphysical, and ethical forms of inquiry arise in the course of synthetic biology research. An attempt at this work relying on a particular area of synthetic biology will be the aim of this chapter. I focus on the reengineering of metabolic pathways through the manipulation and construction of small DNA-based devices and systems synthetic biology. Rather than focusing on the engineered products or ethical principles that result, I will investigate the processes by which these arise. As such, the attention will be directed to the activities of practitioners, their manipulation of tools, and the use they make of techniques to construct new metabolic devices. Using a science-in-practice approach, I investigate problems at the intersection of science, philosophy of science, and sociology of science. I consider how practitioners within this area of synthetic biology reconfigure biological understanding and ethical categories through active modelling and manipulation of known functional parts, biological pathways for use in the design of microbial machines to solve problems in medicine, technology, and the environment. We might describe this kind of problem-solving as relying on what Helen Longino referred to as āsocial cognitionā or the type of scientific work done within what Hasok Chang calls āsystems of practiceā. My aim in this chapter will be to investigate the relationship that holds between systems of practice within metabolic engineering research and social cognition. I will attempt to show how knowledge and normative valuation are generated from this particular network of practitioners. In doing so, I suggest that the social nature of scientific inquiry is ineliminable to both knowledge acquisition and ethical evaluations
Age-related CNS disorder and early death in transgenic FVB/N mice overexpressing Alzheimer amyloid precursor proteins
AbstractTransgenic FVB/N mice overexpressing human (Hu) or mouse (Mo) Alzheimer amyloid precursor protein (APP695) die early and develop a CNS disorder that includes neophobia and impaired spatial alternation, with diminished glucose utilization and astrogliosis mainly in the cerebrum. Age at onset of neophobia and age at death decrease with increasing levels of brain APP. HuAPP transgenes induce death much earlier than MoAPP transgenes expressed at similar levels. No extracellular amyloid was detected, indicating that some deleterious processes related to APP overexpression are dissociated from formation of amyloid. A similar clinical syndrome occurs spontaneously in ā¼20% of nontransgenic mice when they reach mid-to late-adult life, suggesting that APP overexpression may accelerate a naturally occuring age-related CNS disorder in FVB/N mice
MPHASYS: a mouse phenotype analysis system
<p>Abstract</p> <p>Background</p> <p>Systematic, high-throughput studies of mouse phenotypes have been hampered by the inability to analyze individual animal data from a multitude of sources in an integrated manner. Studies generally make comparisons at the level of genotype or treatment thereby excluding associations that may be subtle or involve compound phenotypes. Additionally, the lack of integrated, standardized ontologies and methodologies for data exchange has inhibited scientific collaboration and discovery.</p> <p>Results</p> <p>Here we introduce a Mouse Phenotype Analysis System (MPHASYS), a platform for integrating data generated by studies of mouse models of human biology and disease such as aging and cancer. This computational platform is designed to provide a standardized methodology for working with animal data; a framework for data entry, analysis and sharing; and ontologies and methodologies for ensuring accurate data capture. We describe the tools that currently comprise MPHASYS, primarily ones related to mouse pathology, and outline its use in a study of individual animal-specific patterns of multiple pathology in mice harboring a specific germline mutation in the DNA repair and transcription-specific gene Xpd.</p> <p>Conclusion</p> <p>MPHASYS is a system for analyzing multiple data types from individual animals. It provides a framework for developing data analysis applications, and tools for collecting and distributing high-quality data. The software is platform independent and freely available under an open-source license <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p
Pioglitazone, Vitamin E, or Placebo for Nonalcoholic Steatohepatitis
Background
Nonalcoholic steatohepatitis is a common liver disease that can progress to cirrhosis. Currently, there is no established treatment for this disease.
Methods
We randomly assigned 247 adults with nonalcoholic steatohepatitis and without diabetes to receive pioglitazone at a dose of 30 mg daily (80 subjects), vitamin E at a dose of 800 IU daily (84 subjects), or placebo (83 subjects), for 96 weeks. The primary outcome was an improvement in histologic features of nonalcoholic steatohepatitis, as assessed with the use of a composite of standardized scores for steatosis, lobular inflammation, hepatocellular ballooning, and fibrosis. Given the two planned primary comparisons, P values of less than 0.025 were considered to indicate statistical significance.
Results
Vitamin E therapy, as compared with placebo, was associated with a significantly higher rate of improvement in nonalcoholic steatohepatitis (43% vs. 19%, P=0.001), but the difference in the rate of improvement with pioglitazone as compared with placebo was not significant (34% and 19%, respectively; P=0.04). Serum alanine and aspartate aminotransferase levels were reduced with vitamin E and with pioglitazone, as compared with placebo (P
Conclusions
Vitamin E was superior to placebo for the treatment of nonalcoholic steatohepatitis in adults without diabetes. There was no benefit of pioglitazone over placebo for the primary outcome; however, significant benefits of pioglitazone were observed for some of the secondary outcomes. (ClinicalTrials.gov number, NCT00063622.
Possible physical and thermodynamical evidence for liquid water at the Phoenix landing site
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95444/1/jgre2665.pd
How Differences in Property Taxes within Cities Affect Urban Sprawl?
This article attempts a formal analysis of the connection between the differentiated property tax rates within urban areas and urban spatial pattern in U.S. cities. We first develop a duocentric-city model where the Central Business District (CBD) is located at the origin while the Suburban Business District (SBD) is at the other end of the city. We show that the ratio between the property tax in the suburbs and in the center has an ambiguous impact on the size of the city. We then test this model empirically to determine this sign by using a dataset of effective property tax rates we developed using GIS techniques for central cities and suburbs in 445 urbanized areas. The empirical analysis estimates the link between these two variables by controlling for variables such as population, income, agricultural rent, commuting cost, climate, crime, and employment structure. Results from the empirical analyses suggest that a lower property tax rate in the suburbs in comparison to the central city is associated with more expansive urban growth and greater level of decentralization of population and employment
Distorted Cognitive Processing in Youth: The Structure of Negative Cognitive Errors and Their Associations with Anxiety
The Childrenās Negative Cognitive Error Questionnaire (CNCEQ) is commonly used to measure four errors in young peopleās thinking, but research has failed to support the factorial validity of the measure. The primary objective of the present study was to examine the factor structure of a refined and extended version of the CNCEQ. Revision of the CNCEQ involved the exclusion of items rated as contaminated, and the addition of items measuring cognitive errors closely associated with anxiety (āthreat conclusionā and āunderestimation of the ability to copeā). A secondary objective was to determine the relation between the negative cognitive errors and anxiety. Principal component analysis of data from 481 children and adolescents indicated five distinct negative cognitive error subscales labeled āunderestimation of the ability to copeā, āpersonalizing without mind readingā, āselective abstractionā, āovergeneralizingā, and āmind readingā which contained the new āthreat conclusionā items. Confirmatory factor analysis in an independent sample of 295 children and adolescents yielded further support for the five-factor solution. All cognitive errors except āselective abstractionā were correlated with anxiety. Multiple regression analysis indicated that the strongest predictors of anxiety were the two subscales containing new items, namely āunderestimation of the ability to copeā and āmind readingā. The results are discussed with respect to further development of the instrument so as to advance the assessment of distorted cognitive processing in young people with internalizing symptoms
Personality Traits, Self-Employment, and Professions
We investigate the effect of broad personality traits' - the Big Five - on an individua's decision to become self-employed. In particular, we test an overall indicator of the entrepreneurial personality. Since we find that the level of self-employment varies considerably across professions, we also perform the analysis for different types of professions, namely, those classified as being in the 'creative class' as compared to the noncreative class. The analysis is based on micro data for individuals of the German Socio Economic Panel (SOEP). We find a significant association between personality traits and the propensity be become self-employed. However, the strength of this link is fairly weak and differs across professions, indicating an important effect of an individual's profession on his or her decision to run an own business
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