647 research outputs found
Anonymity and its Prospects in the Digital World
"This working paper traces the changes undergone by anonymity - and by the discourses surrounding it - in liberal Western societies. The author asks whether the current politicization of the issue is likely to have any impact on the gradual disappearance of opportunities for anonymity that we are currently witnessing and argues that anonymity is an ambivalent but critical feature of the democratic public sphere. The argument proceeds in three stages. It begins with a number of conceptual observations on anonymity. From these, a heuristic framework emerges with which the changes in anonymous communication, and in the role this communication plays in society, can be described. The author then analyses the extent to which options for anonymity have been affected by the revolution in information and communication technologies and concludes by considering how anonymity is framed in public discourse and what impacts this has." (author's abstract)"Das Working Paper untersucht die Veränderungen von Anonymität und den Diskursen über Anonymität in liberalen westlichen Gesellschaften. Der Autor fragt, inwiefern die gegenwärtige Politisierung des Themas einen Einfluss auf das graduelle Verschwinden der Möglichkeiten anonymer Kommunikation haben wird und welche Bedeutung Anonymität für die demokratische Öffentlichkeit hat. Die Analyse vollzieht sich in drei Schritten: Zunächst wird konzeptuell geklärt, was Anonymität ist und darauf aufbauend ein heuristisches Instrument entwickelt mittels dessen sich die Veränderung anonymer Kommunikationsmöglichkeiten in der Gesellschaft beschreiben lassen. Im zweiten Schritt wird dieses Instrument zur Anwendung gebracht, um die sich wandelnden Möglichkeiten anonymer Kommunikation im digitalen Strukturwandel zu porträtieren. Der dritte Teil des Papiers fragt schließlich nach der Art und Weise, wie Anonymität im öffentlichen Diskurs politisiert wird - und sucht die Erfolgsaussichten abzuschätzen, die diese Thematisierung hat, der Entwicklung zu begegnen oder sie gar umzukehren." (Autorenreferat
Dental management considerations for the patient with an acquired coagulopathy. Part 1: Coagulopathies from systemic disease
Current teaching suggests that many patients are at risk for prolonged bleeding during and following invasive dental procedures, due to an acquired coagulopathy from systemic disease and/or from medications. However, treatment standards for these patients often are the result of long-standing dogma with little or no scientific basis. The medical history is critical for the identification of patients potentially at risk for prolonged bleeding from dental treatment. Some time-honoured laboratory tests have little or no use in community dental practice. Loss of functioning hepatic, renal, or bone marrow tissue predisposes to acquired coagulopathies through different mechanisms, but the relationship to oral haemostasis is poorly understood. Given the lack of established, science-based standards, proper dental management requires an understanding of certain principles of pathophysiology for these medical conditions and a few standard laboratory tests. Making changes in anticoagulant drug regimens are often unwarranted and/or expensive, and can put patients at far greater risk for morbidity and mortality than the unlikely outcome of postoperative bleeding. It should be recognised that prolonged bleeding is a rare event following invasive dental procedures, and therefore the vast majority of patients with suspected acquired coagulopathies are best managed in the community practice setting
Rectal Transmission of Transmitted/Founder HIV-1 Is Efficiently Prevented by Topical 1% Tenofovir in BLT Humanized Mice
Rectal microbicides are being developed to prevent new HIV infections in both men and women. We focused our in vivo preclinical efficacy study on rectally-applied tenofovir. BLT humanized mice (n = 43) were rectally inoculated with either the primary isolate HIV-1(JRCSF) or the MSM-derived transmitted/founder (T/F) virus HIV-1(THRO) within 30 minutes following treatment with topical 1% tenofovir or vehicle. Under our experimental conditions, in the absence of drug treatment we observed 50% and 60% rectal transmission by HIV-1(JRCSF) and HIV-1(THRO), respectively. Topical tenofovir reduced rectal transmission to 8% (1/12; log rank p = 0.03) for HIV-1(JRCSF) and 0% (0/6; log rank p = 0.02) for HIV-1(THRO). This is the first demonstration that any human T/F HIV-1 rectally infects humanized mice and that transmission of the T/F virus can be efficiently blocked by rectally applied 1% tenofovir. These results obtained in BLT mice, along with recent ex vivo, Phase 1 trial and non-human primate reports, provide a critically important step forward in the development of tenofovir-based rectal microbicides
Retrieval of snow properties from the Sentinel-3 Ocean and Land Colour Instrument
The Sentinel Application Platform (SNAP) architecture facilitates Earth Observation data processing. In this work, we present results from a new Snow Processor for SNAP. We also describe physical principles behind the developed snow property retrieval technique based on the analysis of Ocean and Land Colour Instrument (OLCI) onboard Sentinel-3A/B measurements over clean and polluted snow fields. Using OLCI spectral reflectance measurements in the range 400–1020 nm, we derived important snow properties such as spectral and broadband albedo, snow specific surface area, snow extent and grain size on a spatial grid of 300 m. The algorithm also incorporated cloud screening and atmospheric correction procedures over snow surfaces. We present validation results using ground measurements from Antarctica, the Greenland ice sheet and the French Alps. We find the spectral albedo retrieved with accuracy of better than 3% on average, making our retrievals sufficient for a variety of applications. Broadband albedo is retrieved with the average accuracy of about 5% over snow. Therefore, the uncertainties of satellite retrievals are close to experimental errors of ground measurements. The retrieved surface grain size shows good agreement with ground observations. Snow specific surface area observations are also consistent with our OLCI retrievals. We present snow albedo and grain size mapping over the inland ice sheet of Greenland for areas including dry snow, melted/melting snow and impurity rich bare ice. The algorithm can be applied to OLCI Sentinel-3 measurements providing an opportunity for creation of long-term snow property records essential for climate monitoring and data assimilation studies—especially in the Arctic region, where we face rapid environmental changes including reduction of snow/ice extent and, therefore, planetary albedo.publishedVersio
Odontostomatologic management of patients receiving oral anticoagulant therapy: a retrospective multicentric study
Introduction: Today, we frequently find patients taking oral anticoagulant therapy (OAT), a prophylaxis against the
occurrence of thromboembolic events. An oral surgeon needs to know how to better manage such patients, in
order to avoid hemorrhagic and thromboembolic complications.
Materials and methods: A group of 193 patients (119 men aged between 46 and 82 and 74 women aged
between 54 and 76) undergoing OAT for more than 5 years were managed with a standardized management
protocol and a 2-months follow-up. The aim of the present study was to apply a protocol, which could provide a
safe intra- and postoperative management of patients on OAT.
Results: Among the 193 patients, only 2 had postoperative complications.
Conclusions: We think that the protocol used in the present study can be used for complete safety in the
treatment of this type of patients.
Keywords: Oral Anticoagulant Therapy (OAT), Tranexamic Acid, Oral Surger
Disruption of Murine mp29/Syf2/Ntc31 Gene Results in Embryonic Lethality with Aberrant Checkpoint Response
Human p29 is a putative component of spliceosomes, but its role in pre-mRNA is elusive. By siRNA knockdown and stable overexpression, we demonstrated that human p29 is involved in DNA damage response and Fanconi anemia pathway in cultured cells. In this study, we generated p29 knockout mice (mp29GT/GT) using the mp29 gene trap embryonic stem cells to study the role of mp29 in DNA damage response in vivo. Interruption of mp29 at both alleles resulted in embryonic lethality. Embryonic abnormality occurred as early as E6.5 in mp29GT/GT mice accompanied with decreased mRNA levels of α-tubulin and Chk1. The reduction of α-tubulin and Chk1 mRNAs is likely due to an impaired post-transcriptional event. An aberrant G2/M checkpoint was found in mp29 gene trap embryos when exposed to aphidicolin and UV light. This embryonic lethality was rescued by crossing with mp29 transgenic mice. Additionally, the knockdown of zfp29 in zebrafish resulted in embryonic death at 72 hours of development postfertilization (hpf). A lower level of acetylated α-tubulin was also observed in zfp29 morphants. Together, these results illustrate an indispensable role of mp29 in DNA checkpoint response during embryonic development
Reconciling conflicting clinical studies of antioxidant supplementation as HIV therapy: a mathematical approach
<p>Abstract</p> <p>Background</p> <p>Small, highly reactive molecules called reactive oxygen species (ROS) play a crucial role in cell signalling and infection control. However, high levels of ROS can cause significant damage to cell structure and function. Studies have shown that infection with the human immunodeficiency virus (HIV) results in increased ROS concentrations, which can in turn lead to faster progression of HIV infection, and cause CD4<sup>+ </sup>T-cell apoptosis. To counteract these effects, clinical studies have explored the possibility of raising antioxidant levels, with mixed results.</p> <p>Methods</p> <p>In this paper, a mathematical model is used to explore this potential therapy, both analytically and numerically. For the numerical work, we use clinical data from both HIV-negative and HIV-positive injection drug users (IDUs) to estimate model parameters; these groups have lower baseline concentrations of antioxidants than non-IDU controls.</p> <p>Results</p> <p>Our model suggests that increases in CD4<sup>+ </sup>T cell concentrations can result from moderate levels of daily antioxidant supplementation, while excessive supplementation has the potential to cause periods of immunosuppression.</p> <p>Conclusion</p> <p>We discuss implications for HIV therapy in IDUs and other populations which may have low baseline concentrations of antioxidants.</p
Search for New Physics in e mu X Data at D0 Using Sleuth: A Quasi-Model-Independent Search Strategy for New Physics
We present a quasi-model-independent search for the physics responsible for
electroweak symmetry breaking. We define final states to be studied, and
construct a rule that identifies a set of relevant variables for any particular
final state. A new algorithm ("Sleuth") searches for regions of excess in those
variables and quantifies the significance of any detected excess. After
demonstrating the sensitivity of the method, we apply it to the semi-inclusive
channel e mu X collected in 108 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV
at the D0 experiment during 1992-1996 at the Fermilab Tevatron. We find no
evidence of new high p_T physics in this sample.Comment: 23 pages, 12 figures. Submitted to Physical Review
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