504 research outputs found

    Close-up Sophiatown : transnational perspectives on past, present and future of an iconic suburb

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    In this article I suggest a different view on Sophiatown’s existence, both in terms of it standing as mythical icon and as a suburb. Instead of continuing the look ‘from afar’ (Hannerz 1994), which positions Sophiatown within the category of desirable ‘global icons’, I turn my gaze deeper into Sophiatown, both as a suburb and an icon. I use the lens of transnationalism to zoom into three scenes in Sophiatown in order to examine what has been ignored and overlooked in previous nar-ratives. Where the global icon stays and focuses on the surface, the transnational perspective focuses on the everyday lives within the icon. Through a series of vignettes, looking at women in Sophiatown’s history, at coffee making with a Greek immigrant, and tales of home with Senegalese businessmen, through a consideration of Bloke Modisane’s post-Sophiatown career, I examine how the time established by focusing on these transnational lives is a time of presence which spans mul-tiple locations. I conclude the article with a final point about the ‘unrepresentability’ of a diverse history in the current ways of narrating history in Sophiatown; and the necessity of extending spaces of representation for other, alternative perspectives

    Learning Informative Health Indicators Through Unsupervised Contrastive Learning

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    Condition monitoring is essential to operate industrial assets safely and efficiently. To achieve this goal, the development of robust health indicators has recently attracted significant attention. These indicators, which provide quantitative real-time insights into the health status of industrial assets over time, serve as valuable tools for fault detection and prognostics. In this study, we propose a novel and universal approach to learn health indicators based on unsupervised contrastive learning. Operational time acts as a proxy for the asset's degradation state, enabling the learning of a contrastive feature space that facilitates the construction of a health indicator by measuring the distance to the healthy condition. To highlight the universality of the proposed approach, we assess the proposed contrastive learning framework in two distinct tasks - wear assessment and fault detection - across two different case studies: a milling machines case study and a real condition monitoring case study of railway wheels from operating trains. First, we evaluate if the health indicator is able to learn the real health condition on a milling machine case study where the ground truth wear condition is continuously measured. Second, we apply the proposed method on a real case study of railway wheels where the ground truth health condition is not known. Here, we evaluate the suitability of the learned health indicator for fault detection of railway wheel defects. Our results demonstrate that the proposed approach is able to learn the ground truth health evolution of milling machines and the learned health indicator is suited for fault detection of railway wheels operated under various operating conditions by outperforming state-of-the-art methods. Further, we demonstrate that our proposed approach is universally applicable to different systems and different health conditions

    COP 21 can become a turning point towards sustainable energy systems : paper on behalf of the secretariat of the Club of Rome preparing for COP 21

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    Will climate change stay below the 2 degree target in the 21st century on the basis of the COP 21 results? Looking into challenges and opportunities, this paper answers: To stay below the global 2dt is neither a real choice for the world society nor for businesses and civil societies in specific countries. It is a global guideline, scientifically developed for global negotiations, which should be broken down to national interests and actors. Key questions concerning the energy sector from the perspective of national interests are how to create and sustain a momentum for the inevitable energy transition, how to encourage disruptive innovations, avoid lock in effects, enable rapid deployment of energy efficiency and renewable energies etc. Or in other words: how to get to a competitive, economically benign, inclusive, low carbon and risk minimising energy system. With this background the paper argues that "burden sharing" is a misleading perception of strong climate mitigation strategies. It is more realistic to talk about "benefit sharing", using the monetary benefits and co-benefits of climate mitigation (e.g. energy cost savings, revenues from CO2-tax or emission trading systems) to help vulnerable national and international actors to adapt to the unavoidable climate risks. It has to be demonstrated on country level that the technologies and policy mix of strong climate mitigation and risk-minimising actions are indeed "benefit sharing" strategies which should be chosen anyhow, even if there was no climate change. For China and Germany this paper includes basic findings supporting this view

    COP 21 can become a turning point towards sustainable energy systems: paper on behalf of the secretariat of the Club of Rome preparing for COP 21

    Get PDF
    Will climate change stay below the 2 degree target in the 21st century on the basis of the COP 21 results? Looking into challenges and opportunities, this paper answers: To stay below the global 2dt is neither a real choice for the world society nor for businesses and civil societies in specific countries. It is a global guideline, scientifically developed for global negotiations, which should be broken down to national interests and actors. Key questions concerning the energy sector from the perspective of national interests are how to create and sustain a momentum for the inevitable energy transition, how to encourage disruptive innovations, avoid lock in effects, enable rapid deployment of energy efficiency and renewable energies etc. Or in other words: how to get to a competitive, economically benign, inclusive, low carbon and risk minimising energy system. With this background the paper argues that "burden sharing" is a misleading perception of strong climate mitigation strategies. It is more realistic to talk about "benefit sharing", using the monetary benefits and co-benefits of climate mitigation (e.g. energy cost savings, revenues from CO2-tax or emission trading systems) to help vulnerable national and international actors to adapt to the unavoidable climate risks. It has to be demonstrated on country level that the technologies and policy mix of strong climate mitigation and risk-minimising actions are indeed "benefit sharing" strategies which should be chosen anyhow, even if there was no climate change. For China and Germany this paper includes basic findings supporting this view

    Severity classification of repeated isoflurane anesthesia in C57BL/6JRj mice—Assessing the degree of distress

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    According to the EU Directive 2010/63, the severity of a procedure has to be classified as mild, moderate or severe. General anesthesia is thought to be mild, but the Directive does not differentiate between single and repeated anesthesia. Therefore, we investigated the impact of repeated administration of isoflurane, the most commonly used inhalation anesthetic, on the well-being of adult C57BL/6JRj mice, in comparison to single administrations and to untreated animals, when applied six times for 45 min at an interval of 3–4 days. For the animals anesthetized, excitations, phases of anesthesia, and vital parameters were monitored. Well-being after anesthesia was assessed using a behavioral test battery including luxury behavior like burrowing and nest building behavior, the Mouse Grimace Scale (MGS), the free exploratory paradigm for anxiety-related behavior, home cage activity and the rotarod test for activity, as well as food intake and body weight. Additionally, hair corticosterone and fecal corticosterone metabolites were measured. Our results show that nest building behavior, home cage activity, body weight, and corticosterone concentrations were not influenced by anesthesia, whereas changes in burrowing behavior, the MGS, food intake, and the free exploratory behavior indicated that the well-being of the mice was more affected by repeated than single isoflurane anesthesia. This effect depended on the sex of the animals, with female mice being more susceptible than male mice. However, repeated isoflurane anesthesia caused only short-term mild distress and impairment of well-being, mainly in the immediate postanesthetic period. Well- being stabilized at 8 days after the last anesthesia, at the latest. Therefore, we conclude that when using our anesthesia protocol, the severity of both single and repeated isoflurane anesthesia in C57BL/6JRj mice can be classified as mild. However, within the mild severity category, repeated isoflurane anesthesia ranks higher than single isoflurane anesthesia. Additionally, our results imply that male and female mice can differently perceive the severity of a procedure

    The manifestation of affective symptoms in multiple sclerosis and discussion of the currently available diagnostic assessment tools.

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    INTRODUCTION In addition to physical and cognitive symptoms, patients with multiple sclerosis (MS) have an increased risk of experiencing mental health problems. METHODS This narrative review provides an overview of the appearance and epidemiology of affective symptoms in MS such as depression, anxiety, bipolar disorder, euphoria, and pseudobulbar affect. Furthermore, the association between affective symptoms and quality of life and the currently used diagnostic instruments for assessing these symptoms are considered whereby relevant studies published between 2009 and 2021 were included in the review. RESULTS Patients with mild and moderate disability more frequently reported severe problems with depression and anxiety than severe mobility problems. Apart from the occurrence of depression, little is known about the association of other affective symptoms such as anxiety, bipolar disorder, euphoria, and pseudobulbar affect and subsyndromal symptoms, which fail to meet the diagnostic criteria but are nevertheless a significant source of distress. Although there are a few recommendations in the research to perform routine screenings for diagnosable affective disorders, a standardized diagnostic procedure to assess subsyndromal symptoms is still lacking. As the applied measurements are diverse and show low accuracy to detect these symptoms, patients who experience affective symptoms are less likely to be identified. DISCUSSION In addition to the consideration of definite psychiatric diagnoses, there is an unmet need for a common definition and assessment of disease-related affective symptoms in MS. Future studies should focus on the improvement and standardization of a common diagnostic procedure for subsyndromal affective symptoms in MS to enable integrated and optimal care for patients

    Optimisation of the Read-out Electronics of Muon Drift-Tube Chambers for Very High Background Rates at HL-LHC and Future Colliders

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    In the ATLAS Muon Spectrometer, Monitored Drift Tube (MDT) chambers and sMDT chambers with half of the tube diameter of the MDTs are used for precision muon track reconstruction. The sMDT chambers are designed for operation at high counting rates due to neutron and gamma background irradiation expected for the HL-LHC and future hadron colliders. The existing MDT read-out electronics uses bipolar signal shaping which causes an undershoot of opposite polarity and same charge after a signal pulse. At high counting rates and short electronics dead time used for the sMDTs, signal pulses pile up on the undershoot of preceding background pulses leading to a reduction of the signal amplitude and a jitter in the drift time measurement and, therefore, to a degradation of drift tube efficiency and spatial resolution. In order to further increase the rate capability of sMDT tubes, baseline restoration can be used in the read-out electronics to suppress the pile-up effects. A discrete bipolar shaping circuit with baseline restoration has been developed and used for reading out sMDT tubes under irradiation with a 24 MBq 90Sr source. The measurements results show a substantial improvement of the performance of the sMDT tubes at high counting rates

    Accurate classification of secondary progression in multiple sclerosis using a decision tree

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    BACKGROUND: The absence of reliable imaging or biological markers of phenotype transition in multiple sclerosis (MS) makes assignment of current phenotype status difficult. OBJECTIVE: The authors sought to determine whether clinical information can be used to accurately assign current disease phenotypes. METHODS: Data from the clinical visits of 14,387 MS patients in Sweden were collected. Classifying algorithms based on several demographic and clinical factors were examined. Results obtained from the best classifier when predicting neurologist recorded disease classification were replicated in an independent cohort from British Columbia and were compared to a previously published algorithm and clinical judgment of three neurologists. RESULTS: A decision tree (the classifier) containing only most recently available expanded disability scale status score and age obtained 89.3% (95% confidence intervals (CIs): 88.8-89.8) classification accuracy, defined as concordance with the latest reported status. Validation in the independent cohort resulted in 82.0% (95% CI: 81.0-83.1) accuracy. A previously published classification algorithm with slight modifications achieved 77.8% (95% CI: 77.1-78.4) accuracy. With complete patient history of 100 patients, three neurologists obtained 84.3% accuracy compared with 85% for the classifier using the same data. CONCLUSION: The classifier can be used to standardize definitions of disease phenotype across different cohorts. Clinically, this model could assist neurologists by providing additional information

    Integrating silver compounds and nanoparticles into ceria nanocontainers for antimicrobial applications

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    Silver compounds and nanoparticles (NPs) are gaining increasing interest in medical applications, specifically in the treatment and prevention of biomaterial-related infections. However, the silver release from these materials, resulting in a limited antimicrobial activity, is often difficult to control. In this paper, ceria nanocontainers were synthesized by a template-assisted method and were then used to encapsulate silver nitrate (AgNO₃/CeO₂ nanocontainers). Over the first 30 days, a significant level of silver was released, as determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). A novel type of ceria container containing silver NPs (AgNP/CeO₂ containers) was also developed using two different template removal methods. The presence of AgNPs was confirmed both on the surface and in the interior of the ceria containers by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Upon removal of the template by calcination, the silver was released over a period exceeding three months (>90 days). However, when the template was removed by dissolution, the silver release was shortened to ≤14 days. The antimicrobial activity of the silver-containing CeO₂ containers was observed and the minimum bactericidal concentration (MBC) was determined using the broth dilution method. Investigation on human cells, using a model epithelial barrier cell type (A549 cells), highlighted that all three samples induced a heightened cytotoxicity leading to cell death when exposed to all containers in their raw form. This was attributed to the surface roughness of the CeO₂ nanocontainers and the kinetics of the silver release from the AgNO₃/CeO₂ and AgNP/CeO₂ nanocontainers. In conclusion, despite the need for further emphasis on their biocompatibility, the concept of the AgNP/CeO₂ nanocontainers offers a potentially alternative long-term antibactericidal strategy for implant materials
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