573 research outputs found

    Measurement of sub-pulse-width temporal delays via spectral interference induced by weak value amplification

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    We demonstrate experimentally a scheme to measure small temporal delays, much smaller than the pulse width, between optical pulses. Specifically, we observe an interference effect, based on the concepts of quantum weak measurements and weak value amplification, through which a sub-pulse-width temporal delay between two femtosecond pulses induces a measurable shift of the central frequency of the pulse. The amount of frequency shift, and the accompanying losses of the measurement, can be tailored by postselecting different states of polarization. Our scheme requires only spectrum measurements and linear optics elements, hence greatly facilitating its implementation. Thus it appears to be a promising technique for measuring small and rapidly varying temporal delays.Peer ReviewedPostprint (published version

    A multi-modal approach for activity classification and fall detection

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    "Special issue : Intelligent multisensory systems in support of information society"The society is changing towards a new paradigm in which an increasing number of old adults live alone. In parallel, the incidence of conditions that affect mobility and independence is also rising as a consequence of a longer life expectancy. In this paper, the specific problem of falls of old adults is addressed by devising a technological solution for monitoring these users. Video cameras, accelerometers and GPS sensors are combined in a multi-modal approach to monitor humans inside and outside the domestic environment. Machine learning techniques are used to detect falls and classify activities from accelerometer data. Video feeds and GPS are used to provide location inside and outside the domestic environment. It results in a monitoring solution that does not imply the confinement of the users to a closed environment.This work is funded by National Funds through the FCT-Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project PEst- OE/EEI/UI0752/2011. The work of Davide Carneiro is also supported by a doctoral grant by FCT (SFRH/BD/64890/2009). This work is also partially supported by the Spanish Ministerio de Economía y Competitividad / FEDER under project TIN2010-20845-C03-01

    Mouse parotid salivary gland organoids for the in vitro study of stem cell radiation response

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    Objective: Hyposalivation-related xerostomia is an irreversible, untreatable, and frequent condition after radiotherapy for head and neck cancer. Stem cell therapy is an attractive option of treatment, but demands knowledge of stem cell functioning. Therefore, we aimed to develop a murine parotid gland organoid model to explore radiation response of stem cells in vitro. Materials and Methods: Single cells derived from murine parotid gland organoids were passaged in Matrigel with defined medium to assess self-renewal and differentiation potential. Single cells were irradiated and plated in a 3D clonogenic stem cell survival assay to assess submandibular and parotid gland radiation response. Results: Single cells derived from parotid gland organoids were able to extensively self-renew and differentiate into all major tissue cell types, indicating the presence of potential stem cells. FACS selection for known salivary gland stem cell markers CD24/CD29 did not further enrich for stem cells. The parotid gland organoid-derived stem cells displayed radiation dose–response curves similar to the submandibular gland. Conclusions: Murine parotid gland organoids harbor stem cells with long-term expansion and differentiation potential. This model is useful for mechanistic studies of stem cell radiation response and suggests similar radiosensitivity for the parotid and submandibular gland organoids

    Innovative Mars Global International Exploration (IMaGInE) mission

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    This paper presents the conceptual design of the IMaGInE (Innovative Mars Global International Exploration) Mission whose mission objectives are to deliver a crew of four astronauts to the surface of Deimos and a robotic exploration mission to Phobos for approx-imately 343 days during the years 2031 and 2032, perform surface excursions, technology demonstrations, and In Situ Resource Utilization (ISRU) of the Martian moons as well as site reconnaissance for future human exploration of Mars. This is the winning mission design of the 2016 Revolutionary Aerospace Systems Concepts-Academic Linkage (RASC-AL) competition, awarded with the "Best in Theme," "Best Overall," and "Pio-neering Exceptional Achievement Concept Honor (PEACH)" prizes. This competition was sponsored by NIA and NASA

    The Euclid Science Ground Segment Distributed Infrastructure: System Integration and Challenges

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    The Science Ground Segment (SGS) of the Euclid mission provides distributed and redundant data storage and processing, federating nine Science Data Centres (SDCs) and a Science Operations Centre. The SGS reference architecture is based on loosely coupled systems and services, broadly organized into a common infrastructure of transverse software components and the scientific data Processing Functions. The SGS common infrastructure includes: 1) the Euclid Archive System (EAS), a central metadata repository which inventories, indexes and localizes the huge amount of distributed data; 2) a Distributed Storage System of EAS, providing a unified view of the SDCs storage systems and supporting several transfer protocols; 3) an Infrastructure Abstraction Layer, isolating the scientific data processing software from the underlying IT infrastructure and providing a common, lightweight workflow management system; 4) a Common Orchestration System, performing a balanced distribution of data and processing among the SDCs. Virtualization is another key element of the SGS infrastructure. We present the status of the Euclid SGS software infrastructure, the prototypes developed and the continuous system integration and testing performed through the Euclid “SGS Challenges”

    Association of CYP2D6 genotype and tamoxifen metabolites with breast cancer recurrence in a low-dose trial

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    Low-dose tamoxifen halves recurrence in non-invasive breast cancer without significant adverse events. Some adjuvant trials with tamoxifen 20 mg/day had shown an association between low endoxifen levels (9–16 nM) and recurrence, but no association with CYP2D6 was shown in the NSABP P1 and P2 prevention trials. We studied the association of CYP2D6 genotype and tamoxifen metabolites with tumor biomarkers and recurrence in a randomized phase III trial of low-dose tamoxifen. Median (IQR) endoxifen levels at year 1 were 8.4 (5.3–11.4) in patients who recurred vs 7.5 (5.1–10.2) in those who did not recur (p = 0.60). Tamoxifen and metabolites significantly decreased C-reactive protein (CRP, p < 0.05), and a CRP increase after 3 years was associated with higher risk of recurrence (HR = 4.37, 95% CI, 1.14–16.73, P = 0.03). In conclusion, endoxifen is below 9 nM in most subjects treated with 5 mg/day despite strong efficacy and there is no association with recurrence, suggesting that the reason for tamoxifen failure is not poor drug metabolism.publishedVersio

    The Euclid Science Ground Segment Distributed Infrastructure: System Integration and Challenges

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    The Science Ground Segment (SGS) of the Euclid mission provides distributed and redundant data storage and processing, federating nine Science Data Centres (SDCs) and a Science Operations Centre. The SGS reference architecture is based on loosely coupled systems and services, broadly organized into a common infrastructure of transverse software components and the scientific data Processing Functions. The SGS common infrastructure includes: 1) the Euclid Archive System (EAS), a central metadata repository which inventories, indexes and localizes the huge amount of distributed data; 2) a Distributed Storage System of EAS, providing a unified view of the SDCs storage systems and supporting several transfer protocols; 3) an Infrastructure Abstraction Layer, isolating the scientific data processing software from the underlying IT infrastructure and providing a common, lightweight workflow management system; 4) a Common Orchestration System, performing a balanced distribution of data and processing among the SDCs. Virtualization is another key element of the SGS infrastructure. We present the status of the Euclid SGS software infrastructure, the prototypes developed and the continuous system integration and testing performed through the Euclid “SGS Challenges”

    The low density, hot Jupiter TOI-640 b is on a polar orbit

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    TOI-640 b is a hot, puffy Jupiter with a mass of 0.57±0.020.57 \pm 0.02 MJ_{\rm J} and radius of 1.72±0.051.72 \pm 0.05 RJ_{\rm J}, orbiting a slightly evolved F-type star with a separation of 6.330.06+0.076.33^{+0.07}_{-0.06} R_\star. Through spectroscopic in-transit observations made with the HARPS spectrograph, we measured the Rossiter-McLaughlin effect, analysing both in-transit radial velocities and the distortion of the stellar spectral lines. From these observations, we find the host star to have a projected obliquity of λ=184±3\lambda=184\pm3^\circ. From the TESS light curve, we measured the stellar rotation period, allowing us to determine the stellar inclination, i=232+3i_\star=23^{+3\circ}_{-2}, meaning we are viewing the star pole-on. Combining this with the orbital inclination allowed us to calculate the host star obliquity, ψ=104±2\psi=104\pm2^\circ. TOI-640 b joins a group of planets orbiting over stellar poles within the range 8012580^\circ-125^\circ. The origin of this orbital configuration is not well understood.Comment: 15 pages, 12 figures, accepted for publication in A&A, in pres

    Development and Potential Usefulness of the COVID-19 Ag Respi-Strip Diagnostic Assay in a Pandemic Context

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    Introduction: COVID-19 Ag Respi-Strip, an immunochromatographic (ICT) assay for the rapid detection of SARS-CoV-2 antigen on nasopharyngeal specimen, has been developed to identify positive COVID-19 patients allowing prompt clinical and quarantine decisions. In this original research article, we describe the conception, the analytical and clinical performances as well as the risk management of implementing the COVID-19 Ag Respi-Strip in a diagnostic decision algorithm. Materials and Methods: Development of the COVID-19 Ag Respi-Strip resulted in a ready-to-use ICT assay based on a membrane technology with colloidal gold nanoparticles using monoclonal antibodies directed against the SARS-CoV and SARS-CoV-2 highly conserved nucleoprotein antigen. Four hundred observations were recorded for the analytical performance study and thirty tests were analyzed for the crossreactivity study. The clinical performance study was performed in a retrospective multicentric evaluation on aliquots of 328 nasopharyngeal samples. COVID-19 Ag Respi-Strip results were compared with qRT-PCR as golden standard for COVID-19 diagnostics. Results: In the analytical performance study, the reproducibility showed a between-observer disagreement of 1.7%, a robustness of 98%, an overall satisfying user friendliness and no cross-reactivity with other virus-infected nasopharyngeal samples. In the clinical performance study performed in three different clinical laboratories during the ascendant phase of the epidemiological curve, we found an overall sensitivity and specificity of 57.6 and 99.5%, respectively with an accuracy of 82.6%. The cut-off of the ICT was found at CT < 22. User-friendliness analysis and risk management assessment through Ishikawa diagram demonstrate that COVID-19 Ag Respi-Strip may be implemented in clinical laboratories according to biosafety recommendations. Conclusion: The COVID-19 Ag Respi-Strip represents a promising rapid SARS-CoV-2 antigen assay for the first-line diagnosis of COVID-19 in 15min at the peak of the pandemic. Its role in the proposed diagnostic algorithm is complementary to the currently-used molecular techniques
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