Singularity Cancellation in Fermion Loops through Ward Identities

Recently Neumayr and Metzner have shown that the connected N-point density- correlation functions of the two-dimensional and the one-dimensional Fermi gas at one-loop order generically vanish/are regular in the small momentum/small energy-momentum limits. Their result is based on an explicit analysis in the sequel of results of Feldman et al.[2]. In this note we use Ward identities to give a proof of the same fact - in a considerably shortened and simplified way - for any dimension of space.Comment: 11 pages, 2nd corrected and improved version, to appear in Ann. Henri Poincar

Irrelevant Interactions without Composite Operators - A Remark on the Universality of Second Order Phase Transitions

We study the critical behaviour of symmetric $\phi^4_4$ theory including irrelevant terms of the form $\phi^{4+2n}/\Lambda_0^{2n}$ in the bare action, where $\Lambda_0$ is the UV cutoff (corresponding e.g. to the inverse lattice spacing for a spin system). The main technical tool is renormalization theory based on the flow equations of the renormalization group which permits to establish the required convergence statements in generality and rigour. As a consequence the effect of irrelevant terms on the critical behaviour may be studied to any order without using renormalization theory for composite operators. This is a technical simplification and seems preferable from the physical point of view. In this short note we restrict for simplicity to the symmetry class of the Ising model, i.e. one component $\phi^4_4$ theory. The method is general, however.Comment: 13 page

Estimation of time delay by coherence analysis

Using coherence analysis (which is an extensively used method to study the correlations in frequency domain, between two simultaneously measured signals) we estimate the time delay between two signals. This method is suitable for time delay estimation of narrow band coherence signals for which the conventional methods cannot be reliably applied. We show by analysing coupled R\"ossler attractors with a known delay, that the method yields satisfactory results. Then, we apply this method to human pathologic tremor. The delay between simultaneously measured traces of Electroencephalogram (EEG) and Electromyogram (EMG) data of subjects with essential hand tremor is calculated. We find that there is a delay of 11-27 milli-seconds ($ms$) between the tremor correlated parts (cortex) of the brain (EEG) and the trembling hand (EMG) which is in agreement with the experimentally observed delay value of 15 $ms$ for the cortico-muscular conduction time. By surrogate analysis we calculate error-bars of the estimated delay.Comment: 21 pages, 8 figures, elstart.cls file included. Accepted for publication in Physica

Coolant side heat transfer with rotation. Task 3 report: Application of computational fluid dynamics

An experimental and analytical program was conducted to investigate heat transfer and pressure losses in rotating multipass passages with configurations and dimensions typical of modern turbine blades. The objective of this program is the development and verification of improved analysis methods that will form the basis for a design system that will produce turbine components with improved durability. As part of this overall program, a technique is developed for computational fluid dynamics. The specific objectives were to: select a baseline CFD computer code, assess the limitations of the baseline code, modify the baseline code for rotational effects, verify the modified code against benchmark experiments in the literature, and to identify shortcomings in the code as revealed by the verification. The Pratt and Whitney 3D-TEACH CFD code was selected as the vehicle for this program. The code was modified to account for rotating internal flows, and these modifications were evaluated for flow characteristics of those expected in the application. Results can make a useful contribution to blade internal cooling

Myelin, cPLA2, and Azithromycin: Modulation of Macrophage Activation in Spinal Cord Injury Inflammation

Spinal cord injury (SCI) produces a chronic inflammatory state primarily mediated by macrophages consisting of resident microglia and infiltrating monocytes. These chronically activated SCI macrophages adopt a pro-inflammatory, pathological state that continues to cause additional damage after the initial injury and inhibits recovery. While the roles of macrophages in SCI pathophysiology are well documented, the factors contributing to this maladaptive response are poorly understood. Here, we identify the detrimental effects of myelin debris on macrophage physiology and demonstrate a novel, activation state-dependent role for cytosolic phospholipase-A2 (cPLA2) in myelin- mediated potentiation of pro-inflammatory macrophage activation. Macrophage- mediated inflammatory responses are promising therapeutic targets; however, there are very few therapeutic options to treat SCI and none that target macrophages. Here, we provide evidence that treatment with the immunomodulatory antibiotic azithromycin (AZM), initiated after SCI, improves recovery by targeting macrophage activation. There is an urgent need for the development of new therapies for the treatment of SCI. Macrophage-targeted therapies hold great promise; however, these treatment candidates require additional development before they can advance towards clinical use. Here we discuss the continued development of cPLA2 as a therapeutic target, the steps necessary to advance AZM towards clinical use, and lastly, we review additional macrophage-targeted therapies currently in development. Collectively this body of work identifies key mechanisms driving macrophage pathophysiology after SCI and identifies macrophage-targeted therapies that reduce this neuroinflammation to improve recovery after SCI

Preliminary note on the paleomagnetic reversal record obtained from two Mallorcan caves

[spa] Muestras de sedimentos obtenidas en dos cuevas mallorquinas con la ayuda del Speleo Club Mallorca, ponen de manifiesto una inversión del campo magnético terrestre en puntos sincrónicos de ambos depósitos (alrededor de un metro de profundidad). Esta inversión es la primera que ha sido observada en sedimentos de cueva, pareciendo corresponder al período "Mungo" que finalizó hace unos 32.000 años. Previamente, el "Mungo" solamente había sido identificado en sedimentos lacustres de Australia y en sedimentos marinos profundos del Golfo de Méjico.[eng] Sediments samples obtained from two Mallorcan caves with the help of the Speleo Club Mallorca show a reversal of the earth's magnetic field at synchronous points in the two deposits, circa 1m (Fig. 1). This reversal is the first ever observed in cave sediments and it is thought to be the Mungo event which ended about 32.000 B.P. Previously, the Mungo event had only identified in lake sediments from Australia and deepsea sediments from the Gulf of México (Freed and Healy 1974)

Energy efficient engine: Low-pressure turbine subsonic cascade component development and integration program

A subsonic cascade test program was conducted to provide technical data for optimizing the blade and vane airfoil designs for the Energy Efficient Engine Low-Pressure Turbine component. The program consisted of three parts. The first involved an evaluation of the low-chamber inlet guide vane. The second, was an evaluation of two candidate aerodynamic loading philosophies for the fourth blade root section. The third part consisted of an evaluation of three candidate airfoil geometries for the fourth blade mean section. The performance of each candidate airfoil was evaluated in a linear cascade configuration. The overall results of this study indicate that the aft-loaded airfoil designs resulted in lower losses which substantiated Pratt & Whitney Aircraft's design philosophy for the Energy Efficient Engine low-pressure turbine component

Myelin as an Inflammatory Mediator: Myelin Interactions with Complement, Macrophages, and Microglia in Spinal Cord Injury

Spinal cord injury (SCI) triggers chronic intraspinal inflammation consisting of activated resident and infiltrating immune cells (especially microglia/macrophages). The environmental factors contributing to this protracted inflammation are not well understood; however, myelin lipid debris is a hallmark of SCI. Myelin is also a potent macrophage stimulus and target of complement‐mediated clearance and inflammation. The downstream effects of these neuroimmune interactions have the potential to contribute to ongoing pathology or facilitate repair. This depends in large part on whether myelin drives pathological or reparative macrophage activation states, commonly referred to as M1 (proinflammatory) or M2 (alternatively) macrophages, respectively. Here we review the processes by which myelin debris may be cleared through macrophage surface receptors and the complement system, how this differentially influences macrophage and microglial activation states, and how the cellular functions of these myelin macrophages and complement proteins contribute to chronic inflammation and secondary injury after SCI