350 research outputs found

    In the Shadow of Asylum Decision-Making: The Knowledge Politics of Country-of-Origin Information

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    Country-of-origin information has secured a central place in European asylum systems, underpinning state decisions on the asylum status of refugee populations. All European states produce this type of information, and dedicated country-of-origin information units are increasingly common. This article analyzes the knowledge politics of country-of-origin information, with a focus on the relation between knowledge and decision. We are interested in this type of knowledge precisely because it is uneasily positioned in-between social scientific methodology and policy decision-making and is infused with a “pulsional normativity.” We distinguish three phases of country-of-origin information production: first, a phase of investigation, where foreign lands are reduced to stable and mobile forms so that they can be studied as research units; second, the concordance of information production, relying on standardized instruments and practical skill; and third, the consolidation phase, which involves the return of country information constructed inside research units back into the administrative and regulatory world. The final section of the article examines how complex and frail information about countries of origin becomes deployed as valid grounds for asylum decision-making

    Report on Alternative Devices to Pyrotechnics on Spacecraft

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    Pyrotechnics accomplish many functions on today's spacecraft, possessing minimum volume/weight, providing instantaneous operation on demand, and requiring little input energy. However, functional shock, safety, and overall system cost issues, combined with emergence and availability of new technologies question their continued use on space missions. Upon request from the National Aeronautics and Space Administration's (NASA) Program Management Council (PMC), Langley Research Center (LaRC) conducted a survey to identify and evaluate state-of-the-art non-explosively actuated (NEA) alternatives to pyrotechnics, identify NEA devices planned for NASA use, and investigate potential interagency cooperative efforts. In this study, over 135 organizations were contacted, including NASA field centers, Department of Defense (DOD) and other government laboratories, universities, and American and European industrial sources resulting in further detailed discussions with over half, and 18 face-to-face briefings. Unlike their single use pyrotechnic predecessors, NEA mechanisms are typically reusable or refurbishable, allowing flight of actual tested units. NEAs surveyed include spool-based devices, thermal knife, Fast Acting Shockless Separation Nut (FASSN), paraffin actuators, and shape memory alloy (SMA) devices (e.g., Frangibolt). The electro-mechanical spool, paraffin actuator and thermal knife are mature, flight proven technologies, while SMA devices have a limited flight history. There is a relationship between shock, input energy requirements, and mechanism functioning rate. Some devices (e.g., Frangibolt and spool based mechanisms) produce significant levels of functional shock. Paraffin, thermal knife, and SMA devices can provide gentle, shock-free release but cannot perform critically timed, simultaneous functions. The FASSN flywheel-nut release device possesses significant potential for reducing functional shock while activating nearly instantaneously. Specific study recommendations include: (1) development of NEA standards, specifically in areas of material characterization, functioning rates, and test methods; (2) a systems level approach to assure successful NEA technology application; and (3) further investigations into user needs, along with industry/government system-level real spacecraft cost benefit trade studies to determine NEA application foci and performance requirements. Additional survey observations reveal an industry and government desire to establish partnerships to investigate remaining unknowns and formulate NEA standards, specifically those driven by SMAs. Finally, there is increased interest and need to investigate alternative devices for such functions as stage/shroud separation and high pressure valving. This paper summarizes results of the NASA-LaRC survey of pyrotechnic alternatives. State of-the-art devices with their associated weight and cost savings are presented. Additionally, a comparison of functional shock characteristics of several devices are shown, and potentially related technology developments are highlighted

    Physical interpretation of stochastic Schroedinger equations in cavity QED

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    We propose physical interpretations for stochastic methods which have been developed recently to describe the evolution of a quantum system interacting with a reservoir. As opposed to the usual reduced density operator approach, which refers to ensemble averages, these methods deal with the dynamics of single realizations, and involve the solution of stochastic Schr\"odinger equations. These procedures have been shown to be completely equivalent to the master equation approach when ensemble averages are taken over many realizations. We show that these techniques are not only convenient mathematical tools for dissipative systems, but may actually correspond to concrete physical processes, for any temperature of the reservoir. We consider a mode of the electromagnetic field in a cavity interacting with a beam of two- or three-level atoms, the field mode playing the role of a small system and the atomic beam standing for a reservoir at finite temperature, the interaction between them being given by the Jaynes-Cummings model. We show that the evolution of the field states, under continuous monitoring of the state of the atoms which leave the cavity, can be described in terms of either the Monte Carlo Wave-Function (quantum jump) method or a stochastic Schr\"odinger equation, depending on the system configuration. We also show that the Monte Carlo Wave-Function approach leads, for finite temperatures, to localization into jumping Fock states, while the diffusion equation method leads to localization into states with a diffusing average photon number, which for sufficiently small temperatures are close approximations to mildly squeezed states.Comment: 12 pages RevTeX 3.0 + 6 figures (GIF format; for higher-resolution postscript images or hardcopies contact the authors.) Submitted to Phys. Rev.

    Tumour necrosis factor production and natural killer cell activity in peripheral blood during treatment with recombinant tumour necrosis factor.

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    Tumour necrosis factor (TNF) has been found to be an important immunomodulator. Among other functions TNF activates natural killer (NK) cells and stimulates monocytes/macrophages in an autocrine fashion. TNF production and NK activity in peripheral blood mononuclear cells were determined in a clinical phase I study in which recombinant human (rh) TNF was administered as a continuous infusion weekly for a period of 8 weeks. Even though TNF production and NK activity were significantly reduced directly after rhTNF infusion the effect proved to be transient and most pronounced at the first rhTNF administration. One day after completion of the rhTNF infusion the peripheral cells released more TNF into the supernatant compared to TNF activity immediately before the rhTNF infusion. This effect was conspicuous in non-stimulated cultures. After repeated rhTNF infusions both stimulated and non-stimulated TNF production of the peripheral blood mononuclear cells was increased. NK cell activity was also enhanced after repeated cycles of rhTNF administration as compared to early rhTNF treatment. Thus, repeated rhTNF infusions lead to a stimulatory effect on TNF production and NK activity of peripheral blood cells

    Recognition of Clostridium difficile PCR-ribotypes 001, 027 and 126/078 using an extended MALDI-TOF MS system

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    During the last decade, Clostridium difficile infection (CDI) increased markedly inside as well as outside of hospitals. In association with the occurrence of new hypervirulent C. difficile strains, CDI became more important. Until now typing of C. difficile strains has been enabled by PCR-ribotyping. However, this method is restricted to specialized laboratories combined with high maintenance cost. Therefore, we tested MALDI-TOF mass spectrometry for typing of C. difficile to provide a fast method for surveillance of CDI. Using a standard set of 25 different C. difficile PCR ribotypes a database was made by different mass spectra recorded in the SARAMIS™ software (AnagnosTec, Zossen, Germany). The database was validated with 355 C. difficile strains belonging to 29 different PCR ribotypes collected prospectively from all submitted feces samples in 2009. The most frequent PCR ribotypes were type 001 (70%), 027 (4.8%) and 078/126 (4.7%). All three types were recognized by MALDI-TOF MS. We conclude that an extended MALDI-TOF system was capable to recognize specific markers for ribotypes 001, 027 and 078/126 allowing an effective identification of these strains

    Mitochondria dysfunction is associated with long-term cognitive impairment in an animal sepsis mode

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    Background: Several different mechanisms have been proposed to explain long-term cognitive impairment in sepsis survivors. The role of persisting mitochondrial dysfunction is not known. We thus sought to determine whether stimulation of mitochondrial dynamics improves mitochondrial function and long-term cognitive impairment in an experimental model of sepsis. Methods: Sepsis was induced in adult Wistar rats by cecal ligation and perforation (CLP). Animals received intracerebroventricular injections of either rosiglitazone (biogenesis activator), rilmenidine, rapamycin (autophagy activators), or n-saline (sham control) once a day on days 7–9 after the septic insult. Cognitive impairment was assessed by inhibitory avoidance and object recognition tests. Animals were killed 24 h, 3 and 10 days after sepsis with the hippocampus and prefrontal cortex removed to determine mitochondrial function. Results: Sepsis was associated with both acute (24 h) and late (10 days) brain mitochondrial dysfunction. Markers of mitochondrial biogenesis, autophagy and mitophagy were not up-regulated during these time points. Activation of biogenesis (rosiglitazone) or autophagy (rapamycin and rilmenidine) improved brain ATP levels and ex vivo oxygen consumption and the long-term cognitive impairment observed in sepsis survivors. Conclusion: Long-term impairment of brain function is temporally related to mitochondrial dysfunction. Activators of autophagy and mitochondrial biogenesis could rescue animals from cognitive impairment

    Molecular imaging biomarkers for immune checkpoint inhibitor therapy

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    Immune checkpoint inhibitors (ICIs) have substantially changed the field of oncology over the past few years. ICIs offer an alternative treatment strategy by exploiting the patients’ immune system, resulting in a T cell mediated anti-tumor response. These therapies are effective in multiple different tumor types. Unfortunately, a substantial group of patients do not respond to ICIs. Molecular imaging, using single-photon emission computed tomography (SPECT) and positron emission tomography (PET), can provide non-invasive whole-body visualization of tumor and immune cell characteristics and might support patient selection or response evaluations for ICI therapies. In this review, recent studies with 18F-fluorodeoxyglucose-PET imaging, imaging of immune checkpoints and imaging of immune cells will be discussed. These studies are until now mainly exploratory, but the first results suggest that molecular imaging biomarkers could have a role in the evaluation of ICI therapy

    Added predictive value of female-specific factors and psychosocial factors for the risk of stroke in women under 50

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    Background and ObjectivesFemale-specific factors and psychosocial factors may be important in the prediction of strokebut are not included in prediction models that are currently used. We investigated whetheraddition of these factors would improve the performance of prediction models for the risk ofstroke in women younger than 50 years.MethodsWe used data from the Stichting Informatievoorziening voor Zorg en Onderzoek, population-based, primary care database of women aged 20–49 years without a history of cardiovasculardisease. Analyses were stratified by 10-year age intervals at cohort entry. Cox proportionalhazards models to predict stroke risk were developed, including traditional cardiovascularfactors, and compared with models that additionally included female-specific and psychosocialfactors. We compared the risk models using the c-statistic and slope of the calibration curve at afollow-up of 10 years. We developed an age-specific stroke risk prediction tool that may helpcommunicating the risk of stroke in clinical practice.ResultsWe included 409,026 women with a total of 3,990,185 person-years of follow-up. Strokeoccurred in 2,751 women (incidence rate 6.9 [95% CI 6.6–7.2] per 10,000 person-years).Models with only traditional cardiovascular factors performed poorly to moderately in all agegroups: 20–29 years: c-statistic: 0.617 (95% CI 0.592–0.639); 30–39 years: c-statistic: 0.615(95% CI 0.596–0.634); and 40–49 years: c-statistic: 0.585 (95% CI 0.573–0.597). After addingthe female-specific and psychosocial risk factors to the reference models, the model discrimi-nation increased moderately, especially in the age groups 30–39 (Dc-statistic: 0.019) and 40–49years (Dc-statistic: 0.029) compared with the reference models, respectively.DiscussionThe addition of female-specific factors and psychosocial risk factors improves the discrimina-tory performance of prediction models for stroke in women younger than 50 years.Paroxysmal Cerebral Disorder
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