160 research outputs found
Momentum reconstruction of particles in the forward muon trigger system of the ATLAS detector
No full textWe devise a feed forward neural network which identifies the charge and momentum of muons in the forward trigger system of the ATLAS detector. We use second order learning methods to train the network on a set comprising a few thousand simulated events over a wide range of energies and transverse momenta. The network produces an unbiased estimate of the particles' momentum and charge. On a test set, the charge is correctly identified in 94% of the events, and the mean relative error in transverse momentum is about 1:9%. [email protected] y [email protected] z [email protected] 1 Introduction The Large Hadron Collider (LHC) is an accelerator which will bring proton beams into head-on collisions at energies of 14 TeV and luminosity L = 10 34 cm \Gamma2 s \Gamma1 , higher than ever before. The high luminosity produces an event flux of about 1 GHz. In such an environment there is a unique importance to an efficient triggering system operating within the short bun..
Physiological synergy between IL-1β and insulin on glucose disposal and macrophage activity
No full textType 2 diabetes (T2D) is an inflammatory disease associated with infiltration of immune cells into various tissues and increased levels of inflammatory factors including Interleukin-1 β (IL-1β). In pancreatic islets elevated glucose levels stimulate IL-1β production resulting in impaired function and survival of β cells.
Blockade of IL-1β improves T2D, pointing on a major role for IL-1β in the
development and T2D. While the deleterious role of chronic activation of the IL-1 system in T2D is well documented, little is known about its potential physiological role(s).
The aim of the present study is to reveal the physiological role of inflammation
and specifically of IL-1β in metabolism.
In vivo acutely administered IL-1β dose dependently induced insulin secretion even at IL-1β concentrations in the circulation that are below the detection limit.
Together with glucose IL-1β promotes insulin secretion via parasympathetic nerve stimulation. In vitro IL-1β had a dual effect on glucose stimulated insulin secretion: it was beneficial at low doses and deleterious at high doses. The endotoxin lipopolysaccharide (LPS) strongly induced IL-1β, stimulated insulin secretion and improved glucose tolerance. Interestingly, the improvement of glucose tolerance was not only a consequence of increased insulin levels but was also due to direct IL-1β mediated glucose uptake into various tissues. One of the compartments responding to IL-1β with elevated glucose uptake was the cells of the immune system, mainly macrophages. We further show that macrophages significantly contribute to IL-1β mediated glucose disposal from the circulation. In addition, this work provides evidence for a role of insulin in mounting an immune response. Indeed, insulin increased the secretion of IL-1β via the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome preferentially in inflammatory M1 macrophages but not from alternatively activated M2 macrophages. In line with this response, M1 macrophages expressed higher levels of insulin receptors than naïve or M2. Further, insulin had an overall pro inflammatory effect in naïve and inflammatory macrophages, which could be attributed to increased glucose uptake via the GLUT1 glucose transporter
Prognostic role of endocarditis in isolated tricuspid valve surgery. A propensity-weighted study
No full textObjectives
The role of the underlying etiology in isolated tricuspid valve surgery has not been investigated extensively in current literature. Aim of this study was to analyse outcomes of patients undergoing surgery due to endocarditis compared to other pathologies.
Methods
The SURTRI study is a multicenter study enrolling adult patients who underwent isolated tricuspid valve surgery (n = 406, 55 ± 16 y.o.; 56% female) at 13 international sites. Propensity weighted analysis was performed to compare groups (IE group n = 107 vs Not-IE group n = 299).
Results
No difference was found regarding the 30-day mortality (Group IE: 2.8% vs Group Not-IE = 6.8%; OR = 0.45) and major adverse events. Weighted cumulative incidence of cardiac death was significantly higher for patients with endocarditis (p = 0.01). The composite endpoint of cardiac death and reoperation at 6 years was reduced in the Group IE (63.2 ± 6.8% vs 78.9 ± 3.1%; p = 0.022). Repair strategy resulted in an increased late survival even in IE cases.
Conclusions
Data from SURTRI study report acceptable 30-day results but significantly reduced late survival in the setting of endocarditis of the tricuspid valve. Multi-disciplinary approach, repair strategy and earlier treatment may improve outcomes.
© 2022 The Author
Teasing Apart to Bring Together: Gender and Sexuality in Variationist Research
No full textSociolinguistics has long recognized the crucial interconnection between gender and sexuality. This article situates sociolinguists' concern with this topic within a larger discussion of intersectionality as a framework for theorizing identity. It argues that variationist methods provide a mechanism for redressing certain shortcomings of intersectional analysis that have been highlighted by scholars in other disciplines. To illustrate these points, pitch variation is analyzed among a cohort of Israeli lesbians. The author demonstrates how, despite the fact that gender and sexuality are tightly imbricated in the Israeli context, some speakers linguistically attend to these constructs in identifiably distinct ways. It closes by suggesting implications of this argument for the intersectional project more broadly.</jats:p
Thermodynamic analysis of the Brayton-cycle gas turbine under equilibrium chemistry assumptions
No full textA design-point thermodynamic model of the Brayton-cycle gas-turbine
under assumptions of perfect chemical equilibrium is described.
This approach is novel to the best knowledge of the author.
The model uniquely derives an optimum work balance between power
turbine and nozzle as a function of flight conditions and propulsor
efficiency.
The model may easily be expanded to allow analysis and comparison of
arbitrary cycles using any combination of fuel and oxidizer.
The model allows the consideration of engines under a variety of
conditions, from sea level/static to >20 km altitude and flight Mach
numbers greater than 4.
Isentropic or polytropic turbomachinery component efficiency standards
may be used independently for compressor, gas generator turbine and
power turbine.
With a methodology based on the paper by M.V. Casey, “Accounting
for losses” (2007), and using Bridgman’s partial differentials , the
model uniquely describes the properties of a gas turbine solely by
reference to the properties of the gas mixture passing through the
engine.
Turbine cooling is modelled using a method put forward by Kurzke.
Turboshaft, turboprop, separate exhaust turbofan and turbojet engines
may be modelled. Where applicable, optimisation of the power turbine
and exhaust nozzle work split for flight conditions and component
performances is automatically undertaken.
The model is implemented via a VB.net code, which calculates
thermodynamic states and controls the NASA CEA code for the
calculation of thermodynamic properties at those states. Microsoft
Excel® is used as a graphical user interface.
It is explained that comprehensive design-point cycle analysis may
allow novel approaches to off-design analysis, including engine health
management, and that further development may allow the automation of
cycle design, possibly leading to the discovery of opportunities for
novel cycles
Big Data, Big Libraries, Big Problems?: the 2014 LibTech Anti-talk?
No full textThe desire to create automatons is a familiar theme in human history, and during the age of the Enlightenment mechanical automatons became not only an “emblem of the cosmos”, but a symbol of man’s confidence that he would unlock nature’s greatest mysteries and fully harness her power. And yet only a century later, automatons had begun to represent human repression and servitude, a theme later picked up by writers of science fiction. Man’s confidence undeterred, the endgame of the modern scientific and technological mindset, or MSTM, seems to be increasingly coming into view with the rise of “information technology” in general and “Big data” in particular. Along with those who wield them, these can be seen as functioning together as a “mechanical muse” of sorts – surprisingly alluring – and, like a physical automaton can serve as a symbol – a microcosm – of what the MSTM sees (at the very least in practice) as the cosmic machine, our “final frontier”. And yet, individuals who unreflectively participate in these things – giving themselves over to them and seeking the powers afforded by the technology apart from technology’s rightful purposes – in fact yield to the same pragmatism and reductionism those wielding them are captive to. Thus, they ultimately nullify themselves philosophically, politically, and economically – their value increasingly being only the data concerning their persons, and its perceived usefulness. Likewise libraries, the time-honored place of, and symbol for, the intellectual flowering of the individual, will, insofar as they spurn the classical liberal arts (with the idea that things are intrinsically good, and in the case of humans, special as well) in favor of the alluring embrace of MSTM-driven “information technology” and Big data - unwittingly contribute to their irrelevance and demise as they find themselves increasingly less needed, valued, wanted. Likewise for the liberal arts as a whole, and in fact history itself, if the acid of a “science” untethered from what is, in fact, good (intrinsically), continues to gain strengt
Over-expression of a retinol dehydrogenase (SRP35/DHRS7C) in skeletal muscle activates mTORC2, enhances glucose metabolism and muscle performance
No full textSRP-35 is a short-chain dehydrogenase/reductase belonging to the DHRS7C dehydrogenase/ reductase family 7. Here we show that its over-expression in mouse skeletal muscles induces enhanced muscle performance in vivo, which is not related to alterations in excitation-contraction coupling but rather linked to enhanced glucose metabolism. Over-expression of SRP-35 causes increased phosphorylation of AktS473, triggering plasmalemmal targeting of GLUT4 and higher glucose uptake into muscles. SRP-35 signaling involves RARα and RARγ (non-genomic effect), PI3K and mTORC2. We also demonstrate that all-trans retinoic acid, a downstream product of the enzymatic activity of SRP-35, mimics the effect of SRP-35 in skeletal muscle, inducing a synergistic effect with insulin on AKTS473 phosphorylation. These results indicate that SRP-35 affects skeletal muscle metabolism and may represent an important target for the treatment of metabolic diseases
Confidence Regions for the Multinomial Parameter With Small Sample Size
No full textConsider the observation of n iid realizations of an experiment with d >= 2 possible outcomes, which corresponds to a single observation of a multinomial distribution M_d(n; p) where p is an unknown discrete distribution on \{1,...,d\}. In many applications, the construction of a confidence region for p when n is small is crucial. This
concrete challenging problem has a long history. It is well known that the confidence regions built from asymptotic statistics do not have good coverage when n is small.
On the other hand, most available methods providing non-asymptotic regions with controlled coverage are limited to the binomial case d = 2. In the present work, we
propose a new method valid for any d >= 2. This method provides condence regions with controlled coverage and small volume, and consists in the inversion of the "cover-
ing collection" associated to level-sets of the likelihood. The behavior when d=n tends to infinity remains an interesting open problem beyond the scope of this work
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