488 research outputs found

    Dualities between Poisson brackets and antibrackets

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    Recently it has been shown that antibrackets may be expressed in terms of Poisson brackets and vice versa for commuting functions in the original bracket. Here we also introduce generalized brackets involving higher antibrackets or higher Poisson brackets where the latter are of a new type. We give generating functions for these brackets for functions in arbitrary involutions in the original bracket. We also give master equations for generalized Maurer-Cartan equations. The presentation is completely symmetric with respect to Poisson brackets and antibrackets.Comment: 24 pages,Latexfile,corrected (2.7-8) and removed text between (2.9) and (2.10

    Game Jam [4Research]

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    International audienceRecent years have witnessed a rise in Game Jams - organized events to create playable prototypes in avery short time frame. Game Jams offer a unique and quick way to prototype games. Beyond that, we believe Game Jams can also be seen as a design research method, situated in the research-through-design tradition, to create knowledge in a fast-paced, collaborative environment. The goal of this Game Jam is thus twofold: first, participants will use the Game Jam approach to investigate a research question; second, participants can, through actual practice, identify advantages and disadvantages of Game Jams as a research method. Hereby the Game Jam workshop provides a unique opportunity for HCI practitioners and researchers to gain experience in applying gameoriented methods for research

    Awake craniotomy versus craniotomy under general anesthesia for the surgical treatment of insular glioma: choices and outcomes

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    Objective: To investigate differences in outcomes in patients who underwent surgery for insular glioma using an awake craniotomy (AC) vs. a craniotomy under general anesthesia (GA). Methods: Data from patients treated at our hospital between 2005 and 2015 were analyzed retrospectively. The preoperative, intraoperative, postoperative, and longer term follow-up characteristics and outcomes of patients who underwent surgery for primary insular glioma using either an AC or GA were compared. Results: Of the 52 identified patients, 24 had surgery using an AC and 28 had surgery under GA. The extent of resection was similar for the two anesthesia techniques: the median extent of resection was 61.4% (IQR: 37.8–74.3%) in the WHO grade <4 AC group vs. 50.5% (IQR: 35.0–71.2%) in the grade <4 GA group and 73.4

    Long-term effect of α1-antitrypsin augmentation therapy on the decline of FEV1 in deficient patients: an analysis of the AIR database

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    Lung structure and function; COPD and smokingEstructura y función pulmonar; EPOC y tabaquismoEstructura i funció pulmonar; MPOC i tabaquismeBackground Patients with ZZ (Glu342Lys) α-1-antitrypsin deficiency (ZZ-AATD) who received augmentation therapy with α-1-antitrypsin (AAT) in randomised controlled trials over 2–3 years failed to show a significant reduction of the annual decline of forced expiratory volume in 1 s (FEV1). Methods To compare the trajectory of FEV1 change during 4 or more years in ZZ-AATD patients with emphysema receiving or not receiving intravenous augmentation therapy, a retrospective analysis of FEV1 values entered in the Alpha-1 International Registry (AIR) of ZZ-AATD patients from five different European countries (Germany, UK, Spain, Italy and the Netherlands) was performed. The post-bronchodilator FEV1 % predicted values for baseline and follow-up over time from patients were analysed using linear mixed effects models. Results Data of 374 patients were analysed: 246 untreated and 128 treated with intravenous AAT augmentation therapy. The mean±sd follow-up duration of the untreated group was 8.60±3.34 years and 8.59±2.62 years for the treated group. The mixed effects model analysis showed a mean FEV1 decline of −0.931% predicted per year (95% CI −1.144 to −0.718) in the untreated group and a decline of −1.016% predicted per year (95% CI −1.319 to −0.7145) in the treated group. The likelihood ratio test showed no difference between the two groups (p=0.71). Conclusion In our study population, we could not detect a significant difference in the annual decline of FEV1 by AAT augmentation treatment over a mean period of 8.6 years. Other approaches are needed to validate any benefit of augmentation therapy.This study was supported by Stichting AIR

    Long-term effect of α1-antitrypsin augmentation therapy on the decline of FEV1 in deficient patients : an analysis of the AIR database

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    Background Patients with ZZ (Glu342Lys) α-1-antitrypsin deficiency (ZZ-AATD) who received augmentation therapy with α-1-antitrypsin (AAT) in randomised controlled trials over 2–3 years failed to show a significant reduction of the annual decline of forced expiratory volume in 1 s (FEV1). Methods To compare the trajectory of FEV1 change during 4 or more years in ZZ-AATD patients with emphysema receiving or not receiving intravenous augmentation therapy, a retrospective analysis of FEV1 values entered in the Alpha-1 International Registry (AIR) of ZZ-AATD patients from five different European countries (Germany, UK, Spain, Italy and the Netherlands) was performed. The post bronchodilator FEV1 % predicted values for baseline and follow-up over time from patients were analysed using linear mixed effects models. Results Data of 374 patients were analysed: 246 untreated and 128 treated with intravenous AAT augmentation therapy. The mean±SD follow-up duration of the untreated group was 8.60±3.34 years and 8.59±2.62 years for the treated group. The mixed effects model analysis showed a mean FEV1 decline of −0.931% predicted per year (95% CI −1.144 to −0.718) in the untreated group and a decline of −1.016% predicted per year (95% CI −1.319 to −0.7145) in the treated group. The likelihood ratio test showed no difference between the two groups ( p=0.71). Conclusion In our study population, we could not detect a significant difference in the annual decline of FEV1 by AAT augmentation treatment over a mean period of 8.6 years. Other approaches are needed to validate any benefit of augmentation therapy

    A solution of a problem of Sophus Lie: Normal forms of 2-dim metrics admitting two projective vector fields

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    We give a complete list of normal forms for the 2-dimensional metrics that admit a transitive Lie pseudogroup of geodesic-preserving transformations and we show that these normal forms are mutually non-isometric. This solves a problem posed by Sophus Lie.Comment: This is an extended version of the paper that will appear in Math. Annalen. Some typos were corrected, references were updated, title was changed (as in the journal version). 31 page

    A survey of tuberculosis infection control practices at the NIH/NIAID/DAIDS-supported clinical trial sites in low and middle income countries.

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    BACKGROUND: Health care associated transmission of Mycobacterium tuberculosis (TB) is well described. A previous survey of infection control (IC) practices at clinical research sites in low and middle income countries (LMIC) funded by the National Institute of Allergy and Infectious Diseases (NIAID) conducting HIV research identified issues with respiratory IC practices. A guideline for TB IC based on international recommendations was developed and promulgated. This paper reports on adherence to the guideline at sites conducting or planning to conduct TB studies with the intention of supporting improvement. METHODS: A survey was developed that assessed IC activities in three domains: facility level measures, administrative control measures and environmental measures. An external site monitor visited each site in 2013-2014, to complete the audit. A central review committee evaluated the site-level survey and results were tabulated. Fisher\u27s exact test was performed to determine whether there were significant differences in practices at sites that had IC officers versus sites that did not have IC officers. Significance was assessed at

    A study of the TEX86 paleothermometer in the water column and sediments of the Santa Barbara Basin, California

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    Particulate organic matter collected during a 2-year period, as part of an ongoing sediment trap study, and a high-resolution sediment record from 1850 to 1987 A.D. from the Santa Barbara Basin were analyzed for TEX86, a temperature proxy based on marine crenarchaeotal membrane lipids. Highest fluxes of crenarchaeotal lipids in the water column were found in May-June 1996 and from October 1996 to January 1997 and, in general, showed a good correlation with mass fluxes. TEX86 reconstructed temperatures from the sediment trap series ranged from 8 to 11°C and were usually substantially lower than sea surface temperatures (SST), indicating that unlike in previous studies, the TEX86 corresponds to subsurface temperatures, likely between 100 and 150 m. TEX86 temperature variations observed in trap samples were not coupled to changes in SST or deep-water temperatures and only to some degree with crenarchaeotal lipid fluxes. This suggests that a complex combination of different depth origins and seasonal growth periods of Crenarchaeota contributed to the variations in TEX86 signal during the annual cycle. TEX86 temperatures in the two sediment cores studied (8-13°C) were also substantially lower than those of instrumental SST records (14-17.5°C) confirming that TEX86 records a subsurface temperature signal in the Santa Barbara Basin. This result highlights the importance of performing calibration studies using sediment traps and core tops before applying the TEX86 temperature proxy in a given study area

    Revised calibration of the mbt-cbt paleotemperature proxy based on branched tetraether membrane lipids in surface soils

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    The MBT-CBT proxy for the reconstruction of paleotemperatures and past soil pH is based on the distribution of branched glycerol dialkyl glycerol tetraether (brGDGT) membrane lipids. The Methylation of Branched Tetraether (MBT) and the Cyclisation of Branched Tetraether (CBT) indices were developed to quantify these distributions, and significant empirical relations between these indices and annual mean air temperature (MAT) and/or soil pH were found in a large data set of soils. In this study, we extended this soil dataset to 278 globally distributed surface soils. Of these soils, 26% contains all nine brGDGTs, while in 63% of the soils the seven most common brGDGTs were detected, and the latter were selected for calibration purposes. This resulted in new transfer functions for the reconstruction of pH based on the CBT index: pH = 7.90-1.97 x CBT (r(2) = 0.70; RMSE = 0.8; n = 176), as well as for MAT based on the CBT index and methylation index based on the seven most abundant GDGTs (defined as MBT'): MAT = 0.81-5.67 x CBT + 31.0 x MBT' (r(2) = 0.59; RMSE = 5.0 degrees C; n = 176). The new transfer function for MAT has a substantially lower correlation coefficient than the original equation (r(2) = 0.77). To investigate possible improvement of the correlation, we used our extended global surface soil dataset to statistically derive the indices that best describe the relations of brGDGT composition with MAT and soil pH. These new indices, however, resulted in only a relatively minor increase in correlation coefficients, while they cannot be explained straightforwardly by physiological mechanisms. The large scatter in the calibration cannot be fully explained by local factors or by seasonality, but MAT for soils from arid regions are generally substantially (up to 20 degrees C) underestimated, suggesting that absolute brGDGT-based temperature records for these areas should be interpreted with caution.<br>The applicability of the new MBT'-CBT calibration function was tested using previously published MBT-CBT-derived paleotemperature records covering the last deglaciation in Central Africa and East Asia, the Eocene-Oligocene boundary and the Paleocene-Eocene thermal maximum. The results show that trends remain similar in all records, but that absolute temperature estimates and the amplitude of temperature changes are lower for most records, and generally in better agreement with independent proxy data

    Universally Coupled Massive Gravity, II: Densitized Tetrad and Cotetrad Theories

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    Einstein's equations in a tetrad formulation are derived from a linear theory in flat spacetime with an asymmetric potential using free field gauge invariance, local Lorentz invariance and universal coupling. The gravitational potential can be either covariant or contravariant and of almost any density weight. These results are adapted to produce universally coupled massive variants of Einstein's equations, yielding two one-parameter families of distinct theories with spin 2 and spin 0. The theories derived, upon fixing the local Lorentz gauge freedom, are seen to be a subset of those found by Ogievetsky and Polubarinov some time ago using a spin limitation principle. In view of the stability question for massive gravities, the proven non-necessity of positive energy for stability in applied mathematics in some contexts is recalled. Massive tetrad gravities permit the mass of the spin 0 to be heavier than that of the spin 2, as well as lighter than or equal to it, and so provide phenomenological flexibility that might be of astrophysical or cosmological use.Comment: 2 figures. Forthcoming in General Relativity and Gravitatio
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