5,496 research outputs found
The Interplay of Politics and Science in the Making of Petr Kropotkinâs Modern Anarchism
This thesis examines the political thought of Petr Kropotkin as a site of interplay between anarchism and science. It explores a dialogue between the diagnostic and remedial aspirations of revolutionary anarchism and certain epistemologies and methodologies of nineteenth- and early twentieth-century scientific thought. On the one hand, I argue that this meeting led to the scientisation of Kropotkinâs anarchist politics, transforming conventional anarchist ideas on the state, capitalism, and revolution. On the other hand, I consider how Kropotkin politicised science, that is, how he inflected certain scientific theories and concepts and turned them into powerful revolutionary devices that equipped his brand of anarchism with new ways to identify political problems and solutions. Kropotkinâs bio-political worldview, his enthusiasm for statistics as a means to visualise society and social law, and his understanding of the âsocialâ as a field for the application of rational and scientific forms of knowledge for the improvement of human populations, had far-reaching implications for the ways he conceptualised and articulated traditional anarchist notions of power, domination, moral corruption, order, and the dissemination of knowledge. I show that in contrast to political philosophers who employ scientific ideas metaphorically to represent political concepts such as sovereignty, stability, and resistance, Kropotkinâs absorption of science was literal. Notions of health, sickness, insanity, degeneration, medicine, and hygiene, for example, did not function analogically in his thought, but were, in fact, some of his key political concerns. The intersection of anarchism and science is presented as an agency stimulating a deep ambivalence in Kropotkinâs thought. This thesis does not portray Kropotkin as an optimist, but as a thinker who wavered between fears of decline and hopes for progress. I bring to light Kropotkinâs anxieties, uncertainties, paradoxes, and contradictions, revealing the oscillation between pessimism and optimism that haunted his scientific and political modernity
A wide-spectrum language for verification of programs on weak memory models
Modern processors deploy a variety of weak memory models, which for
efficiency reasons may (appear to) execute instructions in an order different
to that specified by the program text. The consequences of instruction
reordering can be complex and subtle, and can impact on ensuring correctness.
Previous work on the semantics of weak memory models has focussed on the
behaviour of assembler-level programs. In this paper we utilise that work to
extract some general principles underlying instruction reordering, and apply
those principles to a wide-spectrum language encompassing abstract data types
as well as low-level assembler code. The goal is to support reasoning about
implementations of data structures for modern processors with respect to an
abstract specification.
Specifically, we define an operational semantics, from which we derive some
properties of program refinement, and encode the semantics in the rewriting
engine Maude as a model-checking tool. The tool is used to validate the
semantics against the behaviour of a set of litmus tests (small assembler
programs) run on hardware, and also to model check implementations of data
structures from the literature against their abstract specifications
Long-term controls on continental-scale bedrock river terrace deposition from integrated clast and heavy mineral assemblage analysis: an example from the lower Orange River, Namibia
Establishing relationships between the long-term landscape evolution of drainage basins and the fill of sedimentary basins benefits from analysis of bedrock river terrace deposits. These fragmented detrital archives help to constrain changes in river system character and provenance during sediment transfer from continents (source) to oceans (sink). Thick diamondiferous gravel terrace deposits along the lower Orange River, southern Namibia, provide a rare opportunity to investigate controls on the incision history of a continental-scale bedrock river. Clast assemblage and heavy mineral data from seven localities permit detailed characterisation of the lower Orange River gravel terrace deposits. Two distinct fining-upward gravel terrace deposits are recognised, primarily based on mapped stratigraphic relationships (cross-cutting relationships) and strath and terrace top elevations, and secondarily on the proportion of exotic clasts, referred to as Proto Orange River deposits and Meso Orange River deposits. The older early to middle Miocene Proto Orange River gravels are thick (up to 50 m) and characterised by a dominance of Karoo Supergroup shale and sandstone clasts, whereas the younger Plio-Pleistocene Meso Orange River gravels (6â23 m thick) are characterised by more banded iron formation clasts. Mapping of the downstepping terraces indicates that the Proto gravels were deposited by a higher sinuosity river, and are strongly discordant to the modern Orange River course, whereas the Meso deposits were deposited by a lower sinuosity river. The heavy minerals present in both units comprise magnetite, garnet, amphibole, epidote and ilmenite, with rare titanite and zircon grains. The concentration of amphibole-epidote in the heavy minerals fraction increases from the Proto to the Meso deposits. The decrease in incision depths, recorded by deposit thicknesses above strath terraces, and the differences in clast character (size and roundness) and type between the two units, are ascribed to a more powerful river system during Proto-Orange River time, rather than reworking of older deposits, changes in provenance or climatic variations. In addition, from Proto- to Meso-Orange River times there was an increase in the proportion of sediments supplied from local bedrock sources, including amphibole-epidote in the heavy mineral assemblages derived from the Namaqua Metamorphic Complex. This integrated study demonstrates that clast assemblages are not a proxy for the character of the matrix, and vice versa, because they are influenced by the interplay of different controls. Therefore, an integrated approach is needed to improve prediction of placer mineral deposits in river gravels, and their distribution in coeval deposits downstream
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Endovascular aneurysm sealing for the treatment of ruptured abdominal aortic aneurysms.
PURPOSE: To assess the feasibility and report preliminary results of ruptured abdominal aortic aneurysm (rAAA) repair with endovascular aneurysm sealing (EVAS), a novel therapeutic alternative whose feasibility has not been established in rAAAs due to the unknown effects of the rupture site on the ability to achieve sealing. CASE REPORT: Between December 2013 and April 2014, 5 patients (median age 71 years, range 57-90; 3 men) with rAAAs were treated with the Nellix EVAS system at a single institution. Median aneurysm diameter was 70 mm (range 67-91). Aneurysm morphology in 4 of the 5 patients was noncompliant with instructions for use (IFU) for both EVAS and standard stent-grafts; the remaining patient was outside the IFU for standard stent-grafts but treated with EVAS under standard IFU for the Nellix system. Median Hardman index was 2 (range 0-3). Two patients died of multiorgan failure after re-laparotomy and intraoperative cardiac arrest, respectively. Among survivors, all devices were patent with no signs of endoleak or failed aneurysm sac sealing at 6 months (median follow-up 9.2 months). CONCLUSION: EVAS for the management of infrarenal rAAAs appears feasible. The use of EVAS in emergency repairs may broaden the selection criteria of the current endovascular strategy to include patients with more complex aneurysm morphology
Spontaneous regression of metastatic renal cell carcinoma: case report
Spontaneous regression of metastatic renal cell carcinoma is rarely observed. A case of suspected spontaneous regression of pulmonary metastases following nephrectomy for histologically proven renal cell carcinoma without systemic treatment is presented along with a brief review of the literature
DNAscan: personal computer compatible NGS analysis, annotation and visualisation.
BACKGROUND: Next Generation Sequencing (NGS) is a commonly used technology for studying the genetic basis of biological processes and it underpins the aspirations of precision medicine. However, there are significant challenges when dealing with NGS data. Firstly, a huge number of bioinformatics tools for a wide range of uses exist, therefore it is challenging to design an analysis pipeline. Secondly, NGS analysis is computationally intensive, requiring expensive infrastructure, and many medical and research centres do not have adequate high performance computing facilities and cloud computing is not always an option due to privacy and ownership issues. Finally, the interpretation of the results is not trivial and most available pipelines lack the utilities to favour this crucial step. RESULTS: We have therefore developed a fast and efficient bioinformatics pipeline that allows for the analysis of DNA sequencing data, while requiring little computational effort and memory usage. DNAscan can analyse a whole exome sequencing sample in 1âh and a 40x whole genome sequencing sample in 13âh, on a midrange computer. The pipeline can look for single nucleotide variants, small indels, structural variants, repeat expansions and viral genetic material (or any other organism). Its results are annotated using a customisable variety of databases and are available for an on-the-fly visualisation with a local deployment of the gene.iobio platform. DNAscan is implemented in Python. Its code and documentation are available on GitHub: https://github.com/KHP-Informatics/DNAscan . Instructions for an easy and fast deployment with Docker and Singularity are also provided on GitHub. CONCLUSIONS: DNAscan is an extremely fast and computationally efficient pipeline for analysis, visualization and interpretation of NGS data. It is designed to provide a powerful and easy-to-use tool for applications in biomedical research and diagnostic medicine, at minimal computational cost. Its comprehensive approach will maximise the potential audience of users, bringing such analyses within the reach of non-specialist laboratories, and those from centres with limited funding available
Hepatitis following famotidine: a case report
H2 receptor antagonists can rarely cause idiosyncratic drug reactions leading to acute hepatitis. Famotidine, however, is considered a relatively safe drug with regards to hepatotoxicity. We report a case of a 47 year old male with a history of hepatitis C who developed acute hepatitis on the third day of hospitalization with a dramatic rise in his liver enzymes from normal values at the time of admission. The acute rise in liver enzymes made us consider an adverse drug reaction and famotidine was discontinued. Subsequently his liver enzymes came back to normal in seven days. Thus, physicians should consider famotidine induced hepatitis as a possible etiology of acute liver dysfunction
Effects of ecstasy/polydrug use on memory for associative information
Rationale
Associative learning underpins behaviours that are fundamental to the everyday functioning of the individual. Evidence pointing to learning deficits in recreational drug users merits further examination.
Objectives
A word pair learning task was administered to examine associative learning processes in ecstasy/polydrug users.
Methods
After assignment to either single or divided attention conditions, 44 ecstasy/polydrug users and 48 non-users were presented with 80 word pairs at encoding. Following this, four types of stimuli were presented at the recognition phase: the words as originally paired (old pairs), previously presented words in different pairings (conjunction pairs), old words paired with new words, and pairs of new words (not presented previously). The task was to identify which of the stimuli were intact old pairs.
Results
Ecstasy/ploydrug users produced significantly more false-positive responses overall compared to non-users. Increased long-term frequency of ecstasy use was positively associated with the propensity to produce false-positive responses. It was also associated with a more liberal signal detection theory decision criterion value. Measures of long term and recent cannabis use were also associated with these same word pair learning outcome measures. Conjunction word pairs, irrespective of drug use, generated the highest level of false-positive responses and significantly more false-positive responses were made in the divided attention condition compared to the single attention condition.
Conclusions
Overall, the results suggest that long-term ecstasy exposure may induce a deficit in associative learning and this may be in part a consequence of users adopting a more liberal decision criterion value
Mechanistic insights of epithelial protein lost in neoplasm in prostate cancer metastasis
EPLIN is frequently downregulated or lost in various cancers. The purpose of this study was to evaluate the importance of EPLIN in prostate cancer progression, with particular focus on the mechanistic implications to elucidate EPLIN's tumour suppressive function in cancer. EPLIN expression was evaluated in prostate cancer cell lines and tissues. PCâ3 and LNCaP EPLINα overexpression models were generated through transfection with EPLINα sequence and EPLIN knockdown was achieved using shRNA in CAâHPVâ10 cells. Functional assays were performed to evaluate cellular characteristics and potential mechanisms were evaluated using a protein microarray, and validated using western blot analysis. EPLIN expression was reduced in clinical prostate cancer sections, including hyperplasia (pâ€0.001) and adenocarcinoma (p=0.005), when compared to normal prostate tissue. EPLINα overexpression reduced cell growth, migration and invasion, and influenced transcript, protein and phosphoprotein expression of paxillin, FAK and Src. EPLIN knockdown increased the invasive and migratory nature of CAâHPVâ10 cells and also induced changes to FAK and Src total and/or phospho expression. Functional characterisation of cellular migration and invasion in addition to FAK and Src inhibition demonstrated differential effects between control and EPLINα overexpression and EPLIN knockdown cell lines. This study highlights that EPLIN expression in prostate cancer is able to influence several aspects of cancer cell characteristics, including cell growth, migration and invasion. The mechanism of the tumour suppressive action of EPLIN remains to be fully elucidated; and this study proposes a role for EPLIN's ability to regulate the aggressive characteristics of prostate cancer cells partially through regulating FAK/Src signalling
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