DLR Contribution to the First High Lift Prediction Workshop

DLR’s contribution to the first AIAA High Lift Prediction Workshop (HiLiftPW-1) covers computations of all three scheduled test cases for the NASA trapezoidal wing in high lift configuration. The DLR finite volume code TAU has been employed as the flow solver. In a standard set-up the one-equation turbulence model of Spalart and Allmaras in the original formulation is used to model effects of turbulence. For selected grids and flow conditions, the k-ω SST model of Menter and a differential Reynolds stress model (SSG/LLR-ω ) developed by DLR have been considered. DLR contributed with two hybrid unstructured grid families to the workshop. The grids have been generated with the grid generation packages Centaur and Solar. A grid family with three Solar grids has been generated and provided to the workshop featuring grids of 12·10^6 , 37·10^6 , and 111·10^6 points for test case 1. In addition, a Solar grid of 37·10^6 points has been provided for test case 2, and a grid of 40·10^6 for the configuration including the slat and flap brackets (test case 3). DLR didn’t succeed in generating a fine-grid with the Centaur package. In order to complete a Centaur grid family with three grid levels an extra-coarse grid has been provided. Thus, the three levels of the Centaur grid family are realized by grids of 13·10^6 , 16·10^6 , and 32·10^6 points. In general a go o d agreement between the experimental evidence and the polar computations on the Solar and Centaur grids is found in terms of forces, moments and wing pressure distributions. The wing tip area with the rearward part of the main wing and the flap represents the most challenging part of the configuration, especially at angles of attack around maximum lift. The deviations between the TAU solutions and the experimental data in this area are only weakly influenced by the different grid topologies or turbulence models used. The influence of the grid resolution of both grid families is comparable, taking into account the different absolute resolution levels of both grid families. Including the slat and flap brackets leads to the expected lift decrease. Concerning the convergence properties, a strong dependence on the numerical start-up procedure has been detected in many of the computations at higher angles of attack

Learning HMM State Sequences from Phonemes for Speech Synthesis

AbstractThis paper presents a technique for learning hidden Markov model (HMM) state sequences from phonemes, that combined with modified discrete cosine transform (MDCT), is useful for speech synthesis. Mel-cepstral spectral parameters, currently adopted in the conventional methods as features for HMM acoustic modeling, do not ensure direct speech waveforms reconstruction. In contrast to these approaches, we use an analysis/synthesis technique based on MDCT that guarantees a perfect reconstruction of the signal frame feature vectors and allows for a 50% overlap between frames without increasing the data rate. Experimental results show that the spectrograms achieved with the suggested technique behave very closely to the original spectrograms, and the quality of synthesized speech is conveniently evaluated using the well known Itakura-Saito measure

Lessons Learned from Numerical Simulations of the F-16XL Aircraft at Flight Conditions

Nine groups participating in the Cranked Arrow Wing Aerodynamics Project International (CAWAPI) project have contributed steady and unsteady viscous simulations of a full-scale, semi-span model of the F-16XL aircraft. Three different categories of flight Reynolds/Mach number combinations were computed and compared with flight-test measurements for the purpose of code validation and improved understanding of the flight physics. Steady-state simulations are done with several turbulence models of different complexity with no topology information required and which overcome Boussinesq-assumption problems in vortical flows. Detached-eddy simulation (DES) and its successor delayed detached-eddy simulation (DDES) have been used to compute the time accurate flow development. Common structured and unstructured grids as well as individually-adapted unstructured grids were used. Although discrepancies are observed in the comparisons, overall reasonable agreement is demonstrated for surface pressure distribution, local skin friction and boundary velocity profiles at subsonic speeds. The physical modeling, steady or unsteady, and the grid resolution both contribute to the discrepancies observed in the comparisons with flight data, but at this time it cannot be determined how much each part contributes to the whole. Overall it can be said that the technology readiness of CFD-simulation technology for the study of vehicle performance has matured since 2001 such that it can be used today with a reasonable level of confidence for complex configurations

Optimizing linear routing in the ToLHnet protocol to improve performance over long RS-485 buses

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robust speaker identification in a meeting with short audio segments

The paper proposes a speaker identification scheme for a meeting scenario, that is able to answer the question "is somebody currently talking?", if yes, "who is it?". The suggested system has been designed to identify during a meeting conversation the current speaker from a set of pre-trained speaker models. Experimental results on two databases show the robustness of the approach to the overlapping phenomena and the ability of the algorithm to correctly identify a speaker with short audio segments

Desempenho de pacientes esquizofrênicos no Stroop Color Word Test e responsividade eletrodérmica após administração aguda de canabidiol (CBD)

OBJECTIVE: The last decade has seen increasing evidence of dysfunctions in the endogenous cannabinoid system in schizophrenia and of its relationship with the typical cognitive impairment of the disorder. Studies in animal models, healthy volunteers, and psychotic patients clearly suggest an antipsychotic-like effect of cannabidiol. This study investigated the effects of cannabidiol on selective attention in 28 schizophrenic patients using the Stroop Color Word Test and on these patients' electrodermal responsiveness to auditive stimuli. METHOD: The subjects attended two experimental sessions, the first one without the administration of drugs. In the second session the subjects were divided into three groups that received either a single dose of cannabidiol 300mg or cannabidiol 600mg or placebo. RESULTS: The three groups did not differ significantly with respect to electrodermal measures in the two experimental sessions. When the first and second sessions were compared improved performance was found in all three groups, with patients who received placebo and cannabidiol 300mg performing better than those who received cannabidiol 600mg. CONCLUSION: The single, acute administration of cannabidiol seems to have no beneficial effects on the performance of schizophrenic patients in the Stroop Color Word Test, although the hypothesis that chronic administration may lead to improvement cannot be disregarded.OBJETIVO: Descobertas relativas a possíveis disfunções do sistema canabinóide endógeno na esquizofrenia e sua relação com o prejuízo cognitivo característico da doença têm aumentado durante a última década. Estudos com modelos animais, voluntários saudáveis e pacientes psicóticos sugerem claramente que o canabidiol possui efeitos antipsicóticos. Este estudo investigou os efeitos do canabidiol sobre a atenção seletiva por meio do Stroop Color Word Test e a responsividade eletrodérmica a estímulos auditivos em 28 pacientes com esquizofrenia. MÉTODO: Duas sessões experimentais foram realizadas, a primeira sem a administração de drogas. Na segunda sessão, os sujeitos foram divididos em três grupos que receberam dose única de canabidiol 300mg, canabidiol 600mg ou placebo. RESULTADOS: Os três grupos não diferiram significativamente no que se refere às medidas eletrodérmicas nas duas sessões experimentais. Os três grupos apresentaram melhora da primeira para a segunda avaliação, com os grupos placebo e canabidiol 300mg superiores ao grupo canabidiol 600mg. CONCLUSÃO: A administração aguda de canabidiol em dose única parece não ter efeitos benéficos sobre o desempenho de pacientes com esquizofrenia no Stroop Color Word Test, embora estes dados não sejam suficientes para refutar a hipótese de que a administração continuada de canabidiol possa resultar em melhora no funcionamento cognitivo em esquizofrenia

Summary of the Fourth AIAA CFD Drag Prediction Workshop

Results from the Fourth AIAA Drag Prediction Workshop (DPW-IV) are summarized. The workshop focused on the prediction of both absolute and differential drag levels for wing-body and wing-body-horizontal-tail configurations that are representative of transonic transport air- craft. Numerical calculations are performed using industry-relevant test cases that include lift- specific flight conditions, trimmed drag polars, downwash variations, dragrises and Reynolds- number effects. Drag, lift and pitching moment predictions from numerous Reynolds-Averaged Navier-Stokes computational fluid dynamics methods are presented. Solutions are performed on structured, unstructured and hybrid grid systems. The structured-grid sets include point- matched multi-block meshes and over-set grid systems. The unstructured and hybrid grid sets are comprised of tetrahedral, pyramid, prismatic, and hexahedral elements. Effort is made to provide a high-quality and parametrically consistent family of grids for each grid type about each configuration under study. The wing-body-horizontal families are comprised of a coarse, medium and fine grid; an optional extra-fine grid augments several of the grid families. These mesh sequences are utilized to determine asymptotic grid-convergence characteristics of the solution sets, and to estimate grid-converged absolute drag levels of the wing-body-horizontal configuration using Richardson extrapolation

Proteostasis and ALS: Protocol for a phase II, randomised, double-blind, placebo-controlled, multicentre clinical trial for colchicine in ALS (Co-ALS)

Introduction: Disruptions of proteasome and autophagy systems are central events in amyotrophic lateral sclerosis (ALS) and support the urgent need to find therapeutic compounds targeting these processes. The heat shock protein B8 (HSPB8) recognises and promotes the autophagy-mediated removal of misfolded mutant SOD1 and TDP-43 fragments from ALS motor neurons (MNs), as well as aggregating species of dipeptides produced in C9ORF72-related diseases. In ALS-SOD1 mice and in human ALS autopsy specimens, HSPB8 is highly expressed in spinal cord MNs that survive at the end stage of disease. Moreover, the HSPB8-BAG3-HSP70 complex maintains granulostasis, which avoids conversion of dynamic stress granules (SGs) into aggregation-prone assemblies. We will perform a randomised clinical trial (RCT) with colchicine, which enhances the expression of HSPB8 and of several autophagy players, blocking TDP-43 accumulation and exerting crucial activities for MNs function. Methods and analysis: Colchicine in amyotrophic lateral sclerosis (Co-ALS) is a double-blind, placebo-controlled, multicentre, phase II RCT. ALS patients will be enrolled in three groups (placebo, colchicine 0.01 mg/day and colchicine 0.005 mg/day) of 18 subjects treated with riluzole; treatment will last 30 weeks, and follow-up will last 24 weeks. The primary aim is to assess whether colchicine decreases disease progression as measured by ALS Functional Rating Scale - Revised (ALSFRS-R) at baseline and at treatment end. Secondary aims include assessment of (1) safety and tolerability of Colchicine in patiets with ALS; (2) changes in cellular activity (autophagy, protein aggregation, and SG and exosome secretion) and in biomarkers of disease progression (neurofilaments); (3) survival and respiratory function and (4) quality of life. Preclinical studies with a full assessment of autophagy and neuroinflammation biomarkers in fibroblasts, peripheral blood mononuclear cells and lymphoblasts will be conducted in parallel with clinic assessment to optimise time and resources. Ethics and dissemination: The study protocol was approved by the Ethics Committee of Area Vasta Emilia Nord and by Agenzia Italiana del Farmaco (EUDRACT N.2017-004459-21) based on the Declaration of Helsinki. This research protocol was written without patient involvement. Patients' association will be involved in disseminating the study design and results. Results: will be presented during scientific symposia or published in scientific journals

SARS-CoV-2 multi-variant rapid detector based on graphene transistor functionalized with an engineered dimeric ACE2 receptor

Reliable point-of-care (POC) rapid tests are crucial to detect infection and contain the spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The emergence of several variants of concern (VOC) can reduce binding affinity to diagnostic antibodies, limiting the efficacy of the currently adopted tests, while showing unaltered or increased affinity for the host receptor, angiotensin converting enzyme 2 (ACE2). We present a graphene field-effect transistor (gFET) biosensor design, which exploits the Spike-ACE2 interaction, the crucial step for SARS-CoV-2 infection. Extensive computational analyses show that a chimeric ACE2-Fragment crystallizable (ACE2-Fc) construct mimics the native receptor dimeric conformation. ACE2-Fc functionalized gFET allows in vitro detection of the trimeric Spike protein, outperforming functionalization with a diagnostic antibody or with the soluble ACE2 portion, resulting in a sensitivity of 20 pg/mL. Our miniaturized POC biosensor successfully detects B.1.610 (pre-VOC), Alpha, Beta, Gamma, Delta, Omicron (i.e., BA.1, BA.2, BA.4, BA.5, BA.2.75 and BQ.1) variants in isolated viruses and patient's clinical nasopharyngeal swabs. The biosensor reached a Limit Of Detection (LOD) of 65 cps/mL in swab specimens of Omicron BA.5. Our approach paves the way for a new and reusable class of highly sensitive, rapid and variant-robust SARS-CoV-2 detection systems

COVID-19 and stem cell transplantation; results from an EBMT and GETH multicenter prospective survey

This study reports on 382 COVID-19 patients having undergone allogeneic (n = 236) or autologous (n = 146) hematopoietic cell transplantation (HCT) reported to the European Society for Blood and Marrow Transplantation (EBMT) or to the Spanish Group of Hematopoietic Stem Cell Transplantation (GETH). The median age was 54.1 years (1.0-80.3) for allogeneic, and 60.6 years (7.7-81.6) for autologous HCT patients. The median time from HCT to COVID-19 was 15.8 months (0.2-292.7) in allogeneic and 24.6 months (-0.9 to 350.3) in autologous recipients. 83.5% developed lower respiratory tract disease and 22.5% were admitted to an ICU. Overall survival at 6 weeks from diagnosis was 77.9% and 72.1% in allogeneic and autologous recipients, respectively. Children had a survival of 93.4%. In multivariate analysis, older age (p = 0.02), need for ICU (p < 0.0001) and moderate/high immunodeficiency index (p = 0.04) increased the risk while better performance status (p = 0.001) decreased the risk for mortality. Other factors such as underlying diagnosis, time from HCT, GVHD, or ongoing immunosuppression did not significantly impact overall survival. We conclude that HCT patients are at high risk of developing LRTD, require admission to ICU, and have increased mortality in COVID-19