6,680 research outputs found
Design and fabrication of a tunable InP-based VCSEL using a electro-optic index modulator
International audienceWe present the first vertical surface emitting laser (VCSEL) operating at 1.55-ÎŒm comprising a electro-optic modulator inside its cavity. This material consists of nematic liquid crystal dispersed in a polymer material (nano-PDLC). This first VCSEL exhibits a 10 nm tuning range and an excellent side-mode suppression ratio higher than 20 dB over the whole spectral range. The device is formed by a conventional InP-based active region with an epitaxial and a dielectric Bragg mirror. The nano-PDLC layer length, close to 6 ÎŒm, is in agreement with a tunable laser emission without mode-hopping. Another decisive advantage, compared to mechanical solutions, is the tuning response time which is close to a few 10 ÎŒs to scan the full spectral range, making this device appropriate for some access network functions. This first version is optically pumped and requires 170 volts to obtain a 10 nm tunability
How often is a work-up for Legionella pursued in patients with pneumonia? A retrospective study
<p>Abstract</p> <p>Background</p> <p>It is unclear how often patients with pneumonia are assessed for <it>Legionella </it>in endemic areas. Additionally, the sensitivity of the IDSA/ATS criteria for recommended <it>Legionella </it>testing is undefined.</p> <p>Methods</p> <p>We performed a single-center, retrospective study of patients diagnosed with <it>Legionella </it>pneumonia at our hospital to determine: 1) how often <it>Legionella </it>diagnostic testing is obtained on patients with pneumonia at the time of hospitalization or when pneumonia developed during hospitalization; and 2) how often patient's with <it>Legionella </it>pneumonia met at least one of the five criteria in the IDSA/ATS guidelines recommending a work-up for <it>Legionella</it>. Patients with <it>Legionella </it>pneumonia were identified using an infection control software program. Medical records of these patients were then reviewed.</p> <p>Results</p> <p>Thirty-five percent of patients with a discharge diagnosis of pneumonia had <it>Legionella </it>urine antigen testing and/or a <it>Legionella </it>culture performed. Forty-four percent of patients who had a bronchoscopic specimen sent for microbiologic testing had a <it>Legionella </it>culture performed on the bronchoscopic specimen and/or <it>Legionella </it>urine antigen testing. Of 37 adult patients with <it>Legionella </it>pneumonia, 22 (59%) met the IDSA-ATS criteria recommending <it>Legionella </it>testing.</p> <p>Conclusion</p> <p>Following current recommendations for <it>Legionella </it>testing missed 41% of <it>Legionella </it>cases in adults in our single-center study. A work-up for <it>Legionella </it>(i.e., urine antigen test and/or culture) was performed in less than half of patients who have a bronchoscopic specimen sent for microbiologic testing.</p
Policies of School Building and Intergovernmental Relations : A Study of Local-Governmant Autonomy (<special issue> Middle Report of Corporate Research : "A study on the structure of the educational administration system and the process of the educational policy in post-war Japan")
International audienc
Long-wavelength Vertical-Cavity Surface-Emitting Laser using an electro-optic index modulator with 10-nm tuning range
International audienceWe demonstrate an original approach to achieving a tunable 1.55-”m vertical-cavity surface-emitting laser. The tunability is based on an electro-optic index modulator using nano-sized droplets of liquid crystal as a phase layer. Such an approach can produce a robust and a low-cost device. A 10-nm tuning range with less than 170V applied voltage has been demonstrated. The device is formed by a conventional InP-based active region with an epitaxial and a dielectric Bragg mirror. This optically pumped device exhibits an excellent side-mode suppression ratio of higher than 20-dB over the whole spectral range
CamemBERT: a Tasty French Language Model
Pretrained language models are now ubiquitous in Natural Language Processing.
Despite their success, most available models have either been trained on
English data or on the concatenation of data in multiple languages. This makes
practical use of such models --in all languages except English-- very limited.
In this paper, we investigate the feasibility of training monolingual
Transformer-based language models for other languages, taking French as an
example and evaluating our language models on part-of-speech tagging,
dependency parsing, named entity recognition and natural language inference
tasks. We show that the use of web crawled data is preferable to the use of
Wikipedia data. More surprisingly, we show that a relatively small web crawled
dataset (4GB) leads to results that are as good as those obtained using larger
datasets (130+GB). Our best performing model CamemBERT reaches or improves the
state of the art in all four downstream tasks.Comment: ACL 2020 long paper. Web site: https://camembert-model.f
1.55-”m optically pumped tunable VCSEL based on a nano-polymer dispersive liquid crystal phase modulator
International audienceWe present a new approach to achieve tunability on a 1.55 ÎŒm vertical cavity surface emitting laser (VCSEL). Tunability is achieved thanks to an electro-optic index modulator. This electro-optic material consists in a n-PDLC phase layer introduced inside the VCSEL cavity. N-PDLC comprises nematic liquid crystal dispersed in a polymer material. This first VCSEL exhibits a 10 nm tuning range and an excellent side-mode suppression ratio higher than 20 dB over the whole spectral range. The device is formed by a conventional InP-based active region with an epitaxial and a dielectric Bragg mirror. The n-PDLC layer length, close to 6 ÎŒm, is in agreement with a tunable laser emission without mode-hopping. Another decisive advantage, compared to mechanical solutions, is the tuning response time which is close to a few 10 ÎŒs to scan the full spectral range, making this device appropriate for some access network functions. Voltage values are the main limiting factor, 170 Volts have been required to obtain 10 nm tunability, but material engineering is in progress to improve this point. We presented a first version of the device optically pumped, the next version will be electrically pumped as required for access network applications targeted here
Symbolic powers of monomial ideals and Cohen-Macaulay vertex-weighted digraphs
In this paper we study irreducible representations and symbolic Rees algebras
of monomial ideals. Then we examine edge ideals associated to vertex-weighted
oriented graphs. These are digraphs having no oriented cycles of length two
with weights on the vertices. For a monomial ideal with no embedded primes we
classify the normality of its symbolic Rees algebra in terms of its primary
components. If the primary components of a monomial ideal are normal, we
present a simple procedure to compute its symbolic Rees algebra using Hilbert
bases, and give necessary and sufficient conditions for the equality between
its ordinary and symbolic powers. We give an effective characterization of the
Cohen--Macaulay vertex-weighted oriented forests. For edge ideals of transitive
weighted oriented graphs we show that Alexander duality holds. It is shown that
edge ideals of weighted acyclic tournaments are Cohen--Macaulay and satisfy
Alexander dualityComment: Special volume dedicated to Professor Antonio Campillo, Springer, to
appea
Learning Moore Machines from Input-Output Traces
The problem of learning automata from example traces (but no equivalence or
membership queries) is fundamental in automata learning theory and practice. In
this paper we study this problem for finite state machines with inputs and
outputs, and in particular for Moore machines. We develop three algorithms for
solving this problem: (1) the PTAP algorithm, which transforms a set of
input-output traces into an incomplete Moore machine and then completes the
machine with self-loops; (2) the PRPNI algorithm, which uses the well-known
RPNI algorithm for automata learning to learn a product of automata encoding a
Moore machine; and (3) the MooreMI algorithm, which directly learns a Moore
machine using PTAP extended with state merging. We prove that MooreMI has the
fundamental identification in the limit property. We also compare the
algorithms experimentally in terms of the size of the learned machine and
several notions of accuracy, introduced in this paper. Finally, we compare with
OSTIA, an algorithm that learns a more general class of transducers, and find
that OSTIA generally does not learn a Moore machine, even when fed with a
characteristic sample
A functional PTPN22 polymorphism associated with several autoimmune diseases is not associated with IgA deficiency in the Spanish population
BACKGROUND: The 1858C/T SNP of the PTPN22 gene has been associated with many autoimmune diseases, suggesting the existence of an inflammatory process common to all of them. We studied the association of that polymorphism with immunoglobulin A deficiency (IgAD) following a double approach: a case-control and a TDT study. METHODS: A total of 259 IgAD patients and 455 unrelated matched controls, and 128 families were used for each approach. Comparisons were performed using Chi-Square tests or Fisher's exact test when necessary. RESULTS: No association between the PTPN22 1858C/T SNP and IgA deficiency was found in any case (allelic frequencies 8% vs. 6% in patients and controls, respectively, OR= 1.14 (0.72â1.79), p= 0.56; TDT p = 0.08). CONCLUSION: The result obtained seems to reinforce the consideration of IgA deficiency as a primary immunodeficiency rather than an autoimmune disease
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