401 research outputs found

    A Test of the Theory of DSS Design for User Calibration: The Effects of Expressiveness and Visibility on User Calibration

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    This paper reports a test of the theory of decision support systems design for user calibration that compares the efficiency of the visual computing paradigm with that of the conventional text paradigm over varied levels of problem novelty. Perfect user calibration exists when a user’s confidence in a decision equals the quality of the decision. The laboratory study reported here compared the effects on user calibration of problems depicted either using a text paradigm or visual computing paradigm. The results support the theory. When problems are new and novel, visual depiction improves user calibration. As problems became more familiar and problem novelty decreases, no difference was found in user calibration between subjects exposed to visibility diagrams and those exposed to a traditional text paradigm

    EvoBot: An Open-Source, Modular, Liquid Handling Robot for Scientific Experiments

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    Commercial liquid handling robots are rarely appropriate when tasks change often, which is the case in the early stages of biochemical research. In order to address it, we have developed EvoBot, a liquid handling robot, which is open-source and employs a modular design. The combination of an open-source and a modular design is particularly powerful because functionality is divided into modules with simple, well-defined interfaces, hence customisation of modules is possible without detailed knowledge of the entire system. Furthermore, the modular design allows end-users to only produce and assemble the modules that are relevant for their specific application. Hence, time and money are not wasted on functionality that is not needed. Finally, modules can easily be reused. In this paper, we describe the EvoBot modular design and through scientific experiments such as basic liquid handling, nurturing of microbial fuel cells, and droplet chemotaxis experiments document how functionality is increased one module at a time with a significant amount of reuse. In addition to providing wet-labs with an extendible, open-source liquid handling robot, we also think that modularity is a key concept that is likely to be useful in other robots developed for scientific purposes

    Unmet medical needs and future perspectives for leiomyosarcoma patients-A position paper from the National LeioMyoSarcoma Foundation (NLMSF) and Sarcoma Patients EuroNet (SPAEN)

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    As leiomyosarcoma patients are challenged by the development of metastatic disease, effective systemic therapies are the cornerstone of outcome. However, the overall activity of the currently available conventional systemic treatments and the prognosis of patients with advanced or metastatic disease are still poor, making the treatment of this patient group challenging. Therefore, in a joint effort together with patient networks and organizations, namely Sarcoma Patients EuroNet (SPAEN), the international network of sarcoma patients organizations, and the National LeioMyoSarcoma Foundation (NLMSF) in the United States, we aim to summarize state-of-the-art treatments for leiomyosarcoma patients in order to identify knowledge gaps and current unmet needs, thereby guiding the community to design innovative clinical trials and basic research and close these research gaps. This position paper arose from a leiomyosarcoma research meeting in October 2020 hosted by the NLMSF and SPAEN

    Isotope shifts of the (3s3p)3^3P0,1,2_{0,1,2} - (3s4s)3^3S1_1 Mg I transitions

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    We report measurements of the isotope shifts of the (3s3p)3^3P0,1,2_{0,1,2} - (3s4s)3^3S1_1 Mg I transitions for the stable isotopes 24^{24}Mg (I=0), 25^{25}Mg (I=5/2) and 26^{26}Mg (I=0). Furthermore the 25^{25}Mg 3^3S1_1 hyperfine coefficient A(3^3S1_1) = (-321.6 ±\pm 1.5) MHz is extracted and found to be in excellent agreement with state-of-the-art theoretical predictions giving A(3^3S1_1) = -325 MHz and B(3^3S1_1) ≃10−5\simeq 10^{-5} MHz. Compared to previous measurements, the data presented in this work is improved up to a factor of ten.Comment: 4 pages, 4 figures submitted to PR

    Polysaccharide Processing and Presentation by the MHCII Pathway

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    AbstractThe adaptive immune system functions through the combined action of antigen-presenting cells (APCs) and T cells. Specifically, class I major histocompatibility complex antigen presentation to CD8+ T cells is limited to proteosome-generated peptides from intracellular pathogens while the class II (MHCII) endocytic pathway presents only proteolytic peptides from extracellular pathogens to CD4+ T cells. Carbohydrates have been thought to stimulate immune responses independently of T cells; however, zwitterionic polysaccharides (ZPSs) from the capsules of some bacteria can activate CD4+ T cells. Here we show that ZPSs are processed to low molecular weight carbohydrates by a nitric oxide-mediated mechanism and presented to T cells through the MHCII endocytic pathway. Furthermore, these carbohydrates bind to MHCII inside APCs for presentation to T cells. Our observations begin to elucidate the mechanisms by which some carbohydrates induce important immunologic responses through T cell activation, suggesting a fundamental shift in the MHCII presentation paradigm

    Spectroscopic confirmation of an ultra-faint galaxy at the epoch of reionization

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    Within one billion years of the Big Bang, intergalactic hydrogen was ionized by sources emitting ultraviolet and higher energy photons. This was the final phenomenon to globally affect all the baryons (visible matter) in the Universe. It is referred to as cosmic reionization and is an integral component of cosmology. It is broadly expected that intrinsically faint galaxies were the primary ionizing sources due to their abundance in this epoch. However, at the highest redshifts (z>7.5z>7.5; lookback time 13.1 Gyr), all galaxies with spectroscopic confirmations to date are intrinsically bright and, therefore, not necessarily representative of the general population. Here, we report the unequivocal spectroscopic detection of a low luminosity galaxy at z>7.5z>7.5. We detected the Lyman-α\alpha emission line at ∌10504\sim 10504 {\AA} in two separate observations with MOSFIRE on the Keck I Telescope and independently with the Hubble Space Telescope's slit-less grism spectrograph, implying a source redshift of z=7.640±0.001z = 7.640 \pm 0.001. The galaxy is gravitationally magnified by the massive galaxy cluster MACS J1423.8+2404 (z=0.545z = 0.545), with an estimated intrinsic luminosity of MAB=−19.6±0.2M_{AB} = -19.6 \pm 0.2 mag and a stellar mass of M⋆=3.0−0.8+1.5×108M_{\star} = 3.0^{+1.5}_{-0.8} \times 10^8 solar masses. Both are an order of magnitude lower than the four other Lyman-α\alpha emitters currently known at z>7.5z > 7.5, making it probably the most distant representative source of reionization found to date

    Effects of sea-ice light attenuation and CDOM absorption in the water below the Eurasian sector of central Arctic Ocean (>88°N)

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    This is a study of the optical, physical and biological parameters of sea ice and the water below it at stations (n=25) in the central (>88°N) Eurasian sector of the Arctic Ocean during the summer 2012 record low sea-ice minimum extent. Results show that photosynthetically active radiation (PAR) transmittance of the ice was low (0.09) and apparently related to a high degree of backscattering by air-filled brine channels left by brine draining. The under-ice PAR was also low (8.4±4.5 SD ”mol photons m-2 s-1) and partly related to the low transmittance. There were no significant differences in multi-year and first-year PAR transmittances. In spite of this low under-ice PAR, only 3% of the transmitted PAR through the ice was absorbed by phytoplankton in the water. On average, chlorophyll-a concentrations were low (0.34±0.69 SD mg chl-a m-3) in the water compared to the high (a375=0.52 m-1) coloured dissolved organic matter (CDOM) absorption coefficient with a strong terrestrial optical signature. Two distinct clusters of stations with waters of Pacific and North Atlantic origin were identified based on significant differences in temperature, salinity and CDOM absorption coefficient between water masses. The under-ice light field for bare ice was parameterized as follows: Iz=Io(1-0.55)*(0.09)*exp(-0.17*z)

    Micro‐transfer‐printed III‐V‐on‐silicon C‐band semiconductor optical amplifiers

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    The micro-transfer-printing of prefabricated C-band semiconductor optical amplifiers (SOAs) on a silicon waveguide circuit is reported. The SOAs are 1.35 mm in length and 40 mu m in width. Dense arrays of III-V SOAs are fabricated on the source InP wafer. These can then be micro-transfer-printed on the target SOI photonic circuits in a massively parallel fashion. Additionally, this approach allows for greater flexibility in terms of integrating different epitaxial layer structures on the same SOI waveguide circuit. The technique allows integrating SOAs on a complex silicon photonic circuit platform without changing the foundry process-flow. Two different SOA designs with different optical confinement factor in the quantum wells of the III-V waveguide are discussed. This allows tuning the small-signal gain and output saturation power of the SOA. The design with higher optical confinement in the quantum wells has a small-signal gain of up to 23 dB and an on-chip saturation power of 9.2 mW at 140 mA bias current and the lower optical confinement factor design has a small-signal gain of 17 dB and power saturation of 15 mW at 160 mA of bias current
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