230 research outputs found
Alternatives to neo-Aristotelian virtue ethics
Most contemporary variants of virtue ethics have a neo-Aristotelian timbre. However, standing alongside the neo-Aristotelians are a number of others playing similar tunes on different instruments. This chapter highlights the four most important virtue ethical alternatives to the dominant neo-Aristotelian chorus. These are Michael Slote’s agent-based approach, Linda Zagzebski’s exemplarism, Christine Swanton’s target-centered theory, and Robert Merrihew Adams’s neo-Platonic account. What these four approaches showcase is the range of possible theoretical structures available to virtue ethicists. A virtue ethicist might attempt to define other normative qualities like goodness or rightness in terms of virtuous traits. But she need not. Instead, she might develop a theory in which virtue is fundamental but other normative qualities obey a logic that is at least partially independent of virtue. This chapter draws attention to an exciting range of possibilities for virtue ethics that both critics and advocates alike will want to explore
Characters and roles
For 21st century ethicists, one’s character is thought to be a matter of one’s internal dispositions and their external manifestation in action. This assumption, which is universally accepted among contemporary authors, would not have been shared by 18th century writers. Alongside one’s internal dispositions, Butler, Hutcheson, Hume, and their peers also considered one’s social roles to be part of one’s character. This paper outlines the attractions of the earlier conception of character and responds to objections that must be faced by any account that includes social roles among character’s ingredients
A Multinational Analysis of Mutations and Heterogeneity in PZase, RpsA, and PanD Associated with Pyrazinamide Resistance in M/XDR Mycobacterium tuberculosis.
Pyrazinamide (PZA) is an important first-line drug in all existing and new tuberculosis (TB) treatment regimens. PZA-resistance in M. tuberculosis is increasing, especially among M/XDR cases. Noted issues with PZA Drug Susceptibility Testing (DST) have driven the search for alternative tests. This study provides a comprehensive assessment of PZA molecular diagnostics in M/XDR TB cases. A set of 296, mostly XDR, clinical M. tuberculosis isolates from four countries were subjected to DST for eight drugs, confirmatory Wayne's assay, and whole-genome sequencing. Three genes implicated in PZA resistance, pncA, rpsA, and panD were investigated. Assuming all non-synonymous mutations cause resistance, we report 90% sensitivity and 65% specificity for a pncA-based molecular test. The addition of rpsA and panD potentially provides 2% increase in sensitivity. Molecular heterogeneity in pncA was associated with resistance and should be evaluated as a diagnostic tool. Mutations near the N-terminus and C-terminus of PZase were associated with East-Asian and Euro-American lineages, respectively. Finally, Euro-American isolates are most likely to have a wild-type PZase and escape molecular detection. Overall, the 8-10% resistance without markers may point to alternative mechanisms of resistance. Confirmatory mutagenesis may improve the disconcertingly low specificity but reduce sensitivity since not all mutations may cause resistance
Punishment and protest
Ethicists often approach our task by thinking about the norms that apply to act types. We ask, for example, what it means to punish, to make amends, or to forgive, and what conditions govern the appropriate performance of actions that fall within these types. However, actions often do not fall neatly into only one action type. This chapter discusses two cases that can be interpreted both as acts of protest and as acts of what Linda Radzik calls “informal social punishment.” Since the norms that govern these two types diverge, the fact that a particular action can be interpreted in either of these ways poses a challenge for anyone who might be seeking moral guidance from the type to which the action belongs. The cases highlight a theoretical gap that needs to be filled not only by accounts of social punishment or protest but also by ethicists who would use this approach to think about actions of other overlapping types
Contaminant (PAHs, OCs, PCBs and trace metals) concentrations are declining in axial tissue of sand flathead (Platycephalus bassensis) collected from an urbanised catchment (Port Phillip Bay, Australia)
© 2016 Elsevier Ltd. Concentrations of PAHs, OCs, PCBs and trace metals were determined in the white muscle of sand flathead Platycephalus bassensis collected at 6 locations in Port Phillip Bay during 2015. No PAHs, OCs or PCBs were detected in the white muscle of sand flathead at any of the locations, however measurable levels of As, Cu, Hg, Se and Zn were detected at all sites. Only As and Hg exhibited regional difference in white muscle concentrations, with As present only in a non-toxic organic form and Hg measured at levels that are comparable to levels reported in reference sites in other studies. All contaminants detected in the white muscle of sand flathead collected in Port Phillip Bay in 2015 were below Australian Food Standards guideline values, and by world standards, the Port Phillip Bay sand flathead population is considered minimally contaminated. Furthermore, tissue contaminant concentrations appear to be decreasing over time
Environmental monitoring using next generation sequencing: rapid identification of macroinvertebrate bioindicator species
INTRODUCTION: Invertebrate communities are central to many environmental monitoring programs. In freshwater ecosystems, aquatic macroinvertebrates are collected, identified and then used to infer ecosystem condition. Yet the key step of species identification is often not taken, as it requires a high level of taxonomic expertise, which is lacking in most organizations, or species cannot be identified as they are morphologically cryptic or represent little known groups. Identifying species using DNA sequences can overcome many of these issues; with the power of next generation sequencing (NGS), using DNA sequences for routine monitoring becomes feasible. RESULTS: In this study, we test if NGS can be used to identify species from field-collected samples in an important bioindicator group, the Chironomidae. We show that Cytochrome oxidase I (COI) and Cytochrome B (CytB) sequences provide accurate DNA barcodes for chironomid species. We then develop a NGS analysis pipeline to identifying species using megablast searches of high quality sequences generated using 454 pyrosequencing against comprehensive reference libraries of Sanger-sequenced voucher specimens. We find that 454 generated COI sequences successfully identified up to 96% of species in samples, but this increased up to 99% when combined with CytB sequences. Accurate identification depends on having at least five sequences for a species; below this level species not expected in samples were detected. Incorrect incorporation of some multiplex identifiers (MID’s) used to tag samples was a likely cause, and most errors could be detected when using MID tags on forward and reverse primers. We also found a strong quantitative relationship between the number of 454 sequences and individuals showing that it may be possible to estimate the abundance of species from 454 pyrosequencing data. CONCLUSIONS: Next generation sequencing using two genes was successful for identifying chironomid species. However, when detecting species from 454 pyrosequencing data sets it was critical to include known individuals for quality control and to establish thresholds for detecting species. The NGS approach developed here can lead to routine species-level diagnostic monitoring of aquatic ecosystems
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