911 research outputs found
The right expert at the right time and place: From expertise identification to expertise selection
We propose a unified and complete solution for expert finding in organizations, including not only expertise identification, but also expertise selection functionality. The latter two include the use of implicit and explicit preferences of users on meeting each other, as well as localization and planning as important auxiliary processes. We also propose a solution for privacy protection, which is urgently required in view of the huge amount of privacy sensitive data involved. Various parts are elaborated elsewhere, and we look forward to a realization and usage of the proposed system as a whole
An experiment on an automated literature survey of data-driven speech enhancement methods
The increasing number of scientific publications in acoustics, in general,
presents difficulties in conducting traditional literature surveys. This work
explores the use of a generative pre-trained transformer (GPT) model to
automate a literature survey of 116 articles on data-driven speech enhancement
methods. The main objective is to evaluate the capabilities and limitations of
the model in providing accurate responses to specific queries about the papers
selected from a reference human-based survey. While we see great potential to
automate literature surveys in acoustics, improvements are needed to address
technical questions more clearly and accurately
SuperCam, a 64-pixel heterodyne imaging array for the 870 micron atmospheric window
We report on the development of SuperCam, a 64 pixel, superheterodyne camera
designed for operation in the astrophysically important 870 micron atmospheric
window. SuperCam will be used to answer fundamental questions about the physics
and chemistry of molecular clouds in the Galaxy and their direct relation to
star and planet formation. The advent of such a system will provide an order of
magnitude increase in mapping speed over what is now available and
revolutionize how observational astronomy is performed in this important
wavelength regime. Unlike the situation with bolometric detectors, heterodyne
receiver systems are coherent, retaining information about both the amplitude
and phase of the incident photon stream. From this information a high
resolution spectrum of the incident light can be obtained without multiplexing.
SuperCam will be constructed by stacking eight, 1x8 rows of fixed tuned, SIS
mixers. The IF output of each mixer will be connected to a low-noise, broadband
MMIC amplifier integrated into the mixer block. The instantaneous IF bandwidth
of each pixel will be ~2 GHz, with a center frequency of 5 GHz. A spectrum of
the central 500 MHz of each IF band will be provided by the array spectrometer.
Local oscillator power is provided by a frequency multiplier whose output is
divided between the pixels by using a matrix of waveguide power dividers. The
mixer array will be cooled to 4K by a closed-cycle refrigeration system.
SuperCam will reside at the Cassegrain focus of the 10m Heinrich Hertz
telescope (HHT). A prototype single row of the array will be tested on the HHT
in 2006, with the first engineering run of the full array in late 2007. The
array is designed and constructed so that it may be readily scaled to higher
frequencies.Comment: 12 pages, 14 figures, to be published in the Proceedings of SPIE Vol.
6275, "Astronomical Telescopes and Instrumentation, Millimeter and
Submillimeter Detectors and Instrumentation for Astronomy III
Self-conditioned Embedding Diffusion for Text Generation
Can continuous diffusion models bring the same performance breakthrough on
natural language they did for image generation? To circumvent the discrete
nature of text data, we can simply project tokens in a continuous space of
embeddings, as is standard in language modeling. We propose Self-conditioned
Embedding Diffusion, a continuous diffusion mechanism that operates on token
embeddings and allows to learn flexible and scalable diffusion models for both
conditional and unconditional text generation. Through qualitative and
quantitative evaluation, we show that our text diffusion models generate
samples comparable with those produced by standard autoregressive language
models - while being in theory more efficient on accelerator hardware at
inference time. Our work paves the way for scaling up diffusion models for
text, similarly to autoregressive models, and for improving performance with
recent refinements to continuous diffusion.Comment: 15 page
Colony-forming cells in the adult mouse pancreas are expandable in Matrigel and form endocrine/acinar colonies in laminin hydrogel
The study of hematopoietic colony-forming units using semisolid culture media has greatly advanced the knowledge of hematopoiesis. Here we report that similar methods can be used to study pancreatic colony-forming units. We have developed two pancreatic colony assays that enable quantitative and functional analyses of progenitor-like cells isolated from dissociated adult (2â4 mo old) murine pancreas. We find that a methylcellulose-based semisolid medium containing Matrigel allows growth of duct-like âRing/Denseâ colonies from a rare (âŒ1%) population of total pancreatic single cells. With the addition of roof plate-specific spondin 1, a wingless-int agonist, Ring/Dense colony-forming cells can be expanded more than 100,000-fold when serially dissociated and replated in the presence of Matrigel. When cells grown in Matrigel are then transferred to a Matrigel-free semisolid medium with a unique laminin-based hydrogel, some cells grow and differentiate into another type of colony, which we name âEndocrine/Acinar.â These Endocrine/Acinar colonies are comprised mostly of endocrine- and acinar-like cells, as ascertained by RNA expression analysis, immunohistochemistry, and electron microscopy. Most Endocrine/Acinar colonies contain beta-like cells that secrete insulin/C-peptide in response to D-glucose and theophylline. These results demonstrate robust self-renewal and differentiation of adult Ring/Dense colony-forming units in vitro and suggest an approach to producing beta-like cells for cell replacement of type 1 diabetes. The methods described, which include microfluidic expression analysis of single cells and colonies, should also advance study of pancreas development and pancreatic progenitor cells
Digital Health Data Imperfection Patterns and Their Manifestations in an Australian Digital Hospital
Whilst digital health data provides great benefits for improved and effective patient care and organisational outcomes, the quality of digital health data can sometimes be a significant issue. Healthcare providers are known to spend a significant amount of time on assessing and cleaning data. To address this situation, this paper presents six Digital Health Data Imperfection Patterns that provide insight into data quality issues of digital health data, their root causes, their impact, and how these can be detected. Using the CRISP-DM methodology, we demonstrate the utility and pervasiveness of the patterns at the emergency department of Australia's major tertiary digital hospital. The pattern collection can be used by health providers to identify and prevent key digital health data quality issues contributing to reliable insights for clinical decision making and patient care delivery. The patterns also provide a solid foundation for future research in digital health through its identification of key data quality issues, root causes, detection techniques, and terminology
Metabolic rates of the antarctic amphipod Gondogeneia antarctica at different temperatures and salinities
Changes in environmental factors may deeply affect the energy budget of Antarctic organisms as many of them are stenothermal and/or stenohaline ectotherms. In this context, the aim of this study is to contribute to knowledge on variations in the energy demand of the Antarctic amphipod, Gondogeneia antarctica as a function of temperature and salinity. Experiments were held at the Brazilian Antarctic Station "Comandante Ferraz", under controlled conditions. Animals collected at Admiralty Bay were acclimated to temperatures of 0ÂșC; 2.5ÂșC and 5ÂșC and to salinities of 35, 30 and 25. Thirty measurements were made for each of the nine combinations of the three temperatures and three salinities, totalling 270 measurements. Metabolic rates were assessed by oxygen consumption and total nitrogenous ammonia excretion, in sealed respirometers. When acclimated to salinities 30 or 35, metabolic rates at 0ÂșC and 2.5ÂșC were very similar indicating a possible mechanism of metabolic compensation for temperature. At 5.0ÂșC, however, metabolic rates were always higher. Lower salinities enhanced the effects of temperature on metabolism and ammonia excretion rates. The physiological adaptations of individuals of G. antarctica suggest adaptive mechanisms for energy saving, adjusted to an environment with stable conditions of temperature and salinity. Little is known about the joint effects of salinity and temperature and this study is an important contribution to the understanding of the mechanism of polar organisms in their adaptation to both factors.AlteraçÔes ambientais podem modificar a alocação de energia dos organismos, principalmente dos ectotermos estenotĂ©rmicos e/ou estenohalinos. Nesse contexto, este trabalho contribui com o conhecimento da demanda de energia do anfĂpode antĂĄrtico Gondogeneia antarctica em função da temperatura e da salinidade. Experimentos foram realizados na Estação AntĂĄrtica Brasileira "Comandante Ferraz", em condiçÔes laboratoriais controladas. Animais coletados na BaĂa do Almirantado foram aclimatados a temperaturas de 0ÂșC; 2.5ÂșC e 5ÂșC e salinidades de 35, 30 and 25. Foram realizadas trinta mediçÔes para cada uma das nove combinaçÔes das trĂȘs temperaturas com as trĂȘs salinidades, totalizando 270 mediçÔes. As taxas metabĂłlicas foram estimadas por meio do consumo de oxigĂȘnio e excreção de amĂŽnia, em cĂąmaras respiromĂ©tricas seladas. Quando aclimatados a salinidades 30 ou 35, as taxas metabĂłlicas a 0ÂșC e 2.5ÂșC foram semelhantes indicando possĂvel mecanismo de compensação tĂ©rmica, nessa faixa de variação dos fatores. A 5.0ÂșC, no entanto, as taxas metabĂłlicas foram sempre mais elevadas. Baixas salinidades potencializaram os efeitos da temperatura no consumo de oxigĂȘnio e na excreção de produtos nitrogenados. Os resultados estĂŁo relacionados a mecanismos adaptativos para economia de energia em indivĂduos G. antarctica, ajustados a um ambiente que tem condiçÔes estĂĄveis de temperatura e de salinidade. Pouco se sabe sobre os efeitos conjugados da salinidade e temperatura nos organismos e este trabalho Ă© uma importante contribuição para esse conhecimento.CNPq-PROANTA
Thin films with implemented molecular switches for the application in polymer-based optical waveguides
Complexes like iron (II)-triazoles exhibit spin crossover behavior at ambient temperature and are often considered for possible application. In previous studies, we implemented complexes of this type into polymer nanofibers and first polymer-based optical waveguide sensor systems. In our current study, we synthesized complexes of this type, implemented them into polymers and obtained composites through drop casting and doctor blading. We present that a certain combination of polymer and complex can lead to composites with high potential for optical devices. For this purpose, we used two different complexes [Fe(atrz)3](2ns)2 and [Fe(atrz)3]Cl1.5(BF4)0.5 with different polymers for each composite. We show through transmission measurements and UV/VIS spectroscopy that the optical properties of these composite materials can reversibly change due to the spin crossover effect
PAR1-mediated RhoA activation facilitates CCL2-induced chemotaxis in PC-3 cells
Patients with advanced prostate cancer often exhibit increased activation of the coagulation system. The key activator of the coagulation cascade is the serine protease thrombin which is capable of eliciting numerous cellular responses. We previously reported that the thrombin receptor PAR1 is overexpressed in prostate cancer. To investigate further the role of PAR1 in prostate cancer metastasis, we examined the effects of thrombin activation on cell adhesion and motility in PC-3 prostate cancer cells. Activation of PAR1-induced dynamic cytoskeletal reorganization and reduced PC-3 binding to collagen I, collagen IV, and laminin ( P â<â0.01) but not fibronectin. Expression of the cell surface integrin receptors did not change as assessed by flow cytometry. Immunofluorescence microscopy revealed that PAR1 stimulation caused reorganization of the focal adhesions, suggesting that PAR1 activation in PC-3 cells may be modulating cell adhesion through integrin function but not expression. Furthermore, RhoA was activated upon stimulation with thrombin with subsequent cell contraction, decreased cell adhesion, and induced migration towards monocyte chemoattractant protein 1 (MCP-1; CCL2). Thus, it appears that thrombin stimulation plays a role in prostate cancer metastasis by decreasing cell adhesion to the extracellular matrix and positioning the cell in a âready stateâ for migration in response to a chemotactic signal. Further exploration is needed to determine whether PAR1 activation affects other signaling pathways involved in prostate cancer. J. Cell. Biochem. 101:1292â1300, 2007. © 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56134/1/21252_ftp.pd
Pathological computed tomography features associated with adverse outcomes after mild traumatic brain injury:a TRACK-TBI study with external validation in CENTER-TBI
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