1,153 research outputs found
Prediction of enzyme kinetic parameters based on statistical learning
Values of enzyme kinetic parameters are a key requisite for the kinetic modelling of biochemical systems. For most kinetic parameters, however, not even an order of magnitude is known, so the estimation of model parameters from experimental data remains a major task in systems biology. We propose a statistical approach to infer values for kinetic parameters across species and enzymes making use of parameter values that have been measured under various conditions and that are nowadays stored in databases. We fit the data by a statistical regression model in which the substrate, the combination enzyme-substrate and the combination organism-substrate have a linear effect on the logarithmic parameter value. As a result, we obtain predictions and error ranges for unknown enzyme parameters. We apply our method to decadic logarithmic Michaelis-Menten constants from the BRENDA database and confirm the results with leave-one-out crossvalidation, in which we mask one value at a time and predict it from the remaining data. For a set of 8 metabolites we obtain a standard prediction error of 1.01 for the deviation of the predicted values from the true values, while the standard deviation of the experimental values is 1.16. The method is applicable to other types of kinetic parameters for which many experimental data are available
Tax reform for dirty intermediate goods: Theory and an application to the taxation of freight transport.
Tax reform; Theory; Transport; Working;
Teacher Perceptions of Cooperative Learning
Cooperative learning is a teaching strategy implemented in classrooms in order to prepare students for the future. It enables students to work together to accomplish common learning goals while increasing their understanding of a given topic or concept. The purpose of this research was to learn what cooperative learning methods are most prevalent in elementary and secondary schools and the frequency of their implementation in order to draw correlations and observe trends in student preparation for the future. The researcher used a survey instrument to gather data from a sample comprised of approximately 401 current elementary and secondary teachers within Greenview Community Schools (GCS). In this study, Learning Together (LT) was the most commonly reported cooperative learning method utilized in elementary and secondary classrooms followed by Teams-Games-Tournaments (TGT). This data aligned with the outcomes of previous research
Encoding points on hyperelliptic curves over finite fields in deterministic polynomial time
We present families of (hyper)elliptic curve which admit an efficient
deterministic encoding function
Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment
The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu
Photonics K.K. (HPK) is used in various experiments in particle and
astroparticle physics. We describe the test and calibration of 474 PMTs for the
reactor antineutrino experiment Double Chooz. The unique test setup at
Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate
30 PMTs simultaneously and to characterize the single photo electron response,
transit time spread, linear behaviour and saturation effects, photon detection
efficiency and high voltage calibration
Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment
The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu
Photonics K.K. (HPK) is used in various experiments in particle and
astroparticle physics. We describe the test and calibration of 474 PMTs for the
reactor antineutrino experiment Double Chooz. The unique test setup at
Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate
30 PMTs simultaneously and to characterize the single photo electron response,
transit time spread, linear behaviour and saturation effects, photon detection
efficiency and high voltage calibration
Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment
The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu
Photonics K.K. (HPK) is used in various experiments in particle and
astroparticle physics. We describe the test and calibration of 474 PMTs for the
reactor antineutrino experiment Double Chooz. The unique test setup at
Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate
30 PMTs simultaneously and to characterize the single photo electron response,
transit time spread, linear behaviour and saturation effects, photon detection
efficiency and high voltage calibration
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The Texas Petawatt Laser And Current Experiments
The Texas Petawatt Laser is operational with experimental campaigns executed in both F/40 and F3 target chambers. Recent improvements have resulted in intensities of >2x10(21) W/cm(2) on target. Experimental highlights include, accelerated electron energies of >2 GeV, DD fusion ion temperatures >25 keV and isochorically heated solids to 10-50 eV.Physic
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Safety and Efficacy of Hospital Utilization of Tranexamic Acid in Civilian Adult Trauma Resuscitation
Introduction: Patients with trauma-induced coagulopathies may benefit from the use of antifibrinolytic agents, such as tranexamic acid (TXA). This study evaluated the safety and efficacy of TXA in civilian adults hospitalized with traumatic hemorrhagic shock.Methods: Patients who sustained blunt or penetrating trauma with signs of hemorrhagic shock from June 2014 through July 2018 were considered for TXA treatment. A retrospective control group was formed from patients seen in the same past five years who were not administered TXA and matched based on age, gender, Injury Severity Score (ISS), and mechanism of injury (blunt vs penetrating trauma). The primary outcome of this study was mortality measured at 24 hours, 48 hours, and 28 days. Secondary outcomes included total blood products transfused, hospital length of stay (LOS), intensive care unit LOS, and adverse events. We conducted three pre-specified subgroup analyses to assess outcomes of patients, including (1) those who were severely injured (ISS >15), (2) those who sustained significant blood loss (≥10 units of total blood products transfused), and (3) those who sustained blunt vs penetrating trauma.Results: Propensity matching yielded two cohorts: the hospital TXA group (n = 280) and a control group (n = 280). The hospital TXA group had statistically lower mortality at 28 days (1.1% vs 5%, odds ratio [OR] [0.21], (95% confidence interval [CI], 0.06, 0.72)) and used fewer units of blood products (median = 4 units, interquartile range (IQR) = [1, 10] vs median=7 units, IQR = [2, 12.5] for the hospital TXA and control groups, respectively, (95% CI for the difference in median, -3 to -1). There were no statistically significant differences between groups with regard to 24-hour mortality (1.1% vs 1.1%, OR = 1, 95% CI, 0.20, 5.00), 48-hour mortality (1.1% vs 1.4%, OR [0.74], 95% CI, 0.17, 3.37), hospital LOS (median= 9 days, IQR = (5, 16) vs median =12 days IQR = (6, 22.5) for the hospital TXA and control groups, respectively, 95% CI for the difference in median = (-5 to 0)), and incidence of thromboembolic events (eg, deep vein thrombosis, pulmonary embolism) during hospital stay (0.7% vs 0.7% for the hospital TXA and control group, respectively, OR [1], 95% CI, 0.14 to 7.15). We conducted subgroup analyses on patients with ISS>15, patients transfused with ≥10 units of blood products, and blunt vs penetrating trauma. The results indicated lower 28-day mortality for ISS>15 (1.8% vs 7.1%, OR [0.23], 95% CI, 0.06 to 0.81) and blunt trauma (0.6% vs 6.3%, OR [0.09], 95% CI, 0.01 to 0.75); fewer units of blood products for penetrating trauma (median = 2 units, IQR = (1, 8) vs median = 8 units, IQR = (5, 15) for the hospital TXA and control groups, respectively, 95% CI for the difference in median = (-6 to -3)), and ISS>15 (median = 7 units, IQR = (2, 14) vs median = 8.5 units, IQR = (4, 16) for the hospital TXA and control groups, respectively, 95% CI for the difference in median, -3 to 0).Conclusion: The current study demonstrates a statistically significant reduction in mortality after TXA administration at 28 days, but not at 24 and 48 hours, in patients with traumatic hemorrhagic shock
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