1,072 research outputs found
Cultivation-dependent and cultivation-independent characterisation of hydrocarbon-degrading bacteria in Guaymas Basin sediments
Marine hydrocarbon-degrading bacteria perform a fundamental role in the biodegradation of crude oil and its petrochemical derivatives in coastal and open ocean environments. However, there is a paucity of knowledge on the diversity and function of these organisms in deep-sea sediment. Here we used stable-isotope probing (SIP), a valuable tool to link the phylogeny and function of targeted microbial groups, to investigate polycyclic aromatic hydrocarbon (PAH)-degrading bacteria under aerobic conditions in sediments from Guaymas Basin with uniformly labeled [13C]phenanthrene. The dominant sequences in clone libraries constructed from 13C-enriched bacterial DNA (from phenanthrene enrichments) were identified to belong to the genus Cycloclasticus. We used quantitative PCR primers targeting the 16S rRNA gene of the SIP-identified Cycloclasticus to determine their abundance in sediment incubations amended with unlabeled phenanthrene and showed substantial increases in gene abundance during the experiments. We also isolated a strain, BG-2, representing the SIP-identified Cycloclasticus sequence (99.9% 16S rRNA gene sequence identity), and used this strain to provide direct evidence of phenanthrene degradation and mineralization. In addition, we isolated Halomonas, Thalassospira and Lutibacterium spp. with demonstrable phenanthrene-degrading capacity from Guaymas Basin sediment. This study demonstrates the value of coupling SIP with cultivation methods to identify and expand on the known diversity of PAH-degrading bacteria in the deep-sea
Physicalism, conceptual analysis, and acts of faith
Frank Jackson and the author each take the other to hold a position in philosophy of mind that it is extremely difficult to sustain. This chapter tries to say something about how that can be. It seeks to demonstrate the sanity of Jackson's opponents and the fragility of his own position than to hold out for the truth of any particular doctrine. It wants to bring to the surface an assumption in ontology, which is seen as a crucial part of the grounding of Jackson's particular version of physicalism. Once it is appreciated that this assumption is contestable, Jackson's opponents may be seen in a different light from the one in which they appear in his writings. More generally, a connection will appear between the vast literature on physicalism as a topic in philosophy of mind and the equally vast literature on material constitution as a topic in metaphysics
Cult: A Composite Novel
Cult (redacted)
The first component of the thesis is a composite novel called Cult which falls into two parts with seven narratives in each. Part 1 tracks the protagonist, Ellen, from her first involvement with the cult through to her eventually leaving it. Although fiction, the first half of the book answers the kinds of questions the author is asked when people discover that she was once a sannyasin (a follower of the guru Bhagwan Shree Rajneesh). While the experiences of meditation, group therapy and communal living are all faithfully rendered within the stories, the need for strong characters, narrative drive and a lightness of touch takes precedence.
Part 2 picks up Ellen’s story some twenty or so years later and explores what becomes of her in middle age. It also looks at other groups in society, such as academia, the law and the internet dating community which each have their own jargon, hierarchies, rituals and rules but are not considered to be cults.
The book examines the question raised in the Epigraph, ‘how do we be together when we feel so alone’ with a focus on relationships other than the familial and the romantic.
Collisions, Chasms and Connections: a Performative Exploration of the Composite Novel Form
The second part of the thesis is both a critical and creative response to three contemporary American books: Olive Kitteridge by Elizabeth Strout; A Visit from the Goon Squad by Jennifer Egan; and Legend of a Suicide by David Vann. The critical element comprises a close reading of the three books; a chronological reconstruction of their overarching storylines; and a consideration of what their authors have said about writing the books. It concludes that, in the composite novel, the simultaneous presentation of multiple views and storylines operate much like a 3D image to give the impression of depth to the characters and situations rendered. The creative element of the essay is a playful and personal response to the texts
A Theme Analysis of Experiences Reported by Adult Children of Alcoholics in Online Support Forums
Growing up with an alcoholic parent can have a lasting effect on children and contribute to a variety of challenging outcomes in adulthood. This study identified the various experiences that adult children of alcoholics discuss with their peers in online support groups. Trained coders conducted a thematic analysis of 504 message board posts collected over a period of 60 days from three different online support groups to identify issues that children of alcoholics face in adulthood. Seven themes emerged from the analysis: a) empowerment through support, b) interference of parent in adulthood, c) connection to inner child and need to re-parent, d) low self-esteem and insecurity, e) anger and resentment, f) romantic relationship problems, and g) problems communicating. The results of this study provide insight into the issues that adult children of alcoholics need to address as part of their own recovery and suggest avenues of exploration for practitioners who work with high risk families.Peer reviewe
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Cryptic cycling by electroactive bacterioplankton in Trout Bog Lake
The potential for extracellular electron transfer (EET) is a prevailing genomic feature of humic lake bacterioplankton. However, there has been little evidence for the substantial ecological contribution predicted by genetics. We hypothesized that anoxygenic phototrophic electrotrophs and accompanying heterotrophic electrogens cycle dissolved organic matter (DOM) between oxidized and reduced states. We predicted that such bacterioplankton would exhibit diel-scale oscillations due to the light dependency of photosynthesis. Using Trout Bog Lake in Wisconsin, USA, as our model ecosystem, we profiled the water column with depth-discrete metagenomic, physiochemical, and electrochemical analyses. We observed variation in oxidation reduction potential (ORP) in response to sunlight, initiating at depths populated by anoxygenic phototrophs with EET genes. We developed an automated buoy to measure electric current flow between many pairs of electrodes simultaneously, observing correlation in electron consumption to sunlight. Our results, combined with published metatranscriptomic analysis, indicate the occurrence of electron cycling between phototrophic oxidation (electrotrophic metabolism) by Chlorobium and anaerobic respiration (electrogenic metabolism) by Geothrix, involving DOM. We also repeatedly observed gradual seasonal increases in hypolimnion ORP throughout summer. These diel and seasonal patterns imply that electroactive DOM mediates the ecology of electroactive bacteria in lakes, controlling humic lake methane emissions.IMPORTANCEWe investigated the physical, chemical, and redox characteristics of a bog lake and electrodes hung therein to test the hypothesis that dissolved organic matter is being cycled between oxidized and reduced states by electroactive bacterioplankton powered by phototrophy. To do so, we performed field-based analyses on multiple timescales using both established and novel instrumentation. We paired these analyses with recently developed bioinformatics pipelines for metagenomics data to investigate genes that enable electroactive metabolism and accompanying metabolisms. Our results are consistent with our hypothesis and yet upend some of our other expectations. Our findings have implications for understanding greenhouse gas emissions from lakes, including electroactivity as an integral part of lake metabolism throughout more of the anoxic parts of lakes and for a longer portion of the summer than expected. Our results also give a sense of what electroactivity occurs at given depths and provide a strong basis for future studies
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Metatranscriptomic response of deep ocean microbial populations to infusions of oil and/or synthetic chemical dispersant.
Oil spills are a frequent perturbation to the marine environment that has rapid and significant impacts on the local microbiome. Previous studies have shown that exposure to synthetic dispersant alone did not enhance heterotrophic microbial activity or oxidation rates of specific hydrocarbon components but increased the abundance of some taxa (e.g., Colwellia). In contrast, exposure to oil, but not dispersants, increased the abundance of other taxa (e.g., Marinobacter) and stimulated hydrocarbon oxidation rates. Here, we advance these findings by interpreting metatranscriptomic data from this experiment to explore how and why specific components of the microbial community responded to distinct organic carbon exposure regimes. Dispersant alone was selected for a unique community and for dominant organisms that reflected treatment- and time-dependent responses. Dispersant amendment also led to diverging functional profiles among the different treatments. Similarly, oil alone was selected for a community that was distinct from treatments amended with dispersants. The presence of oil and dispersants with added nutrients led to substantial differences in microbial responses, likely suggesting increased fitness driven by the presence of additional inorganic nutrients. The oil-only additions led to a marked increase in the expression of phages, prophages, transposable elements, and plasmids (PPTEPs), suggesting that aspects of microbial community response to oil are driven by the mobilome, potentially through viral-associated regulation of metabolic pathways in ciliates and flagellates that would otherwise throttle the microbial community through grazing.IMPORTANCEMicrocosm experiments simulated the April 2010 Deepwater Horizon oil spill by applying oil and synthetic dispersants (Corexit EC9500A and EC9527A) to deep ocean water samples. The exposure regime revealed severe negative alterations in the treatments heterotrophic microbial activity and hydrocarbon oxidation rates. We expanded these findings by exploring metatranscriptomic signatures of the microbial communities during the chemical amendments in the microcosm experiments. Here we report how dominant organisms were uniquely associated with treatment- and time-dependent trajectories during the exposure regimes; nutrient availability was a significant factor in driving changes in metatranscriptomic responses. Remarkable signals associated with PPTEPs showed the potential role of mobilome and viral-associated survival responses. These insights underscore the time-dependent environmental perturbations of fragile marine environments under oil and anthropogenic stress
A Comparative Analysis of the Equity Outcomes in Three Sugarcane–Ethanol Systems
This article identifies equity outcomes associated with three biofuel systems in Brazil, Ethiopia, and Guatemala. Acknowledging that winners and losers are socially and politically generated, the article identifies some of the factors behind the distribution of winners and losers along different stages of three sugarcane–ethanol supply chains. Analyzing the outcomes for equity within each case study reveals an uneven distribution that, we argue, is related to the procedure and structure of the given sugarcane–ethanol system, and the recognition of the impacts on different actors within those structures. Increasing equity in sugarcane–ethanol systems will require greater openness in decision-making processes, in order that multiple voices are taken into account in the promotion, production, and consumption of biofuels—particularly those of smaller and less powerful actors
Partner Facilitation and Partner Interference in Individuals' Weight Loss Goals
Drawing on the logic of the relational turbulence model, this study examined the ways in which romantic partners facilitate and interfere with individuals’ weight loss goals. Participants (N = 122) described the ways in which their romantic partner had recently helped or hindered their weight loss at four times over the course of 2 months. We conducted a content analysis of responses to identify themes of partner facilitation (Research Question 1 [RQ1]) and partner interference (RQ2) in individuals’ weight loss goals. Results revealed seven themes of partner facilitation: (a) partner enabling diet, (b) motivation and encouragement, (c) emotional support and positive reinforcement, (d) exercising together, (e) partner enabling exercise, (f) dieting together, and (g) relationship influence and priorities. Four themes of partner interference emerged in the data: (a) inability to plan for healthy meals, (b) inability to control the food environment, (c) preventing or discouraging exercise, and (d) emotional or relational discouragement.Peer reviewe
Book Review: Disability Rights and the American Social Safety Net
Author: Jennifer L. Erkulwater
Reviewer: Karin F. Brockelman
Publisher: Cornell University Press, 2006.
Cloth, ISBN: 0-8014-4417-9, 272 pages
Cost: $42.50, US
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