On-orbit assembly using superquadric potential fields

The autonomous on-orbit assembly of a large space structure is presented using a method based on superquadric artificial potential fields. The final configuration of the elements which form the structure is represented as the minimum of some attractive potential field. Each element of the structure is then considered as presenting an obstacle to the others using a superquadric potential field attached to the body axes of the element. A controller is developed which ensures that the global potential field decreases monotonically during the assembly process. An error quaternion representation is used to define both the attractive and superquadric obstacle potentials allowing the final configuration of the elements to be defined through both relative position and orientation. Through the use of superquadric potentials, a wide range of geometric objects can be represented using a common formalism, while collision avoidance can make use of both translational and rotation maneuvers to reduce total maneuver cost for the assembly process

Digital Twinning remote laboratories for online practical learning, Production & Manufacturing Research

The COVID19 pandemic has demonstrated a need for remote learning and virtual learning applications such as virtual reality (VR) and tabletbased solutions. Creating complex learning scenarios by developers is highly time-consuming and can take over a year. It is also costly to employ teams of system analysts, developers, and 3D artists. There is a requirement to provide a simple method to enable lecturers to create their own content for their laboratory tutorials. Research has been undertaken into developing generic models to enable the semiautomatic creation of virtual learning tools for subjects that require practical interactions with the lab resources. In addition to the system for creating digital twins, a case study describing the creation of a virtual learning application for an electrical laboratory tutorial is presented, demonstrating the feasibility of this approach

O exame clínico de observação da discinese escapular é capaz de diferenciar portadores da disfunção dos normais?

Background:Altered scapular rotation and position have been named scapular dyskinesis. Visual dynamic assessment could be applied to classify this alteration based on the clinical observation of the winging of the inferior medial scapular border (Type I) or of the prominence of the entire medial border (Type II), or by the excessive superior translation of the scapula (Type III).Objective:The aim of this study was to determine if there were differences in scapular rotations (Type I and II) and position (Type III) between a group of subjects with scapular dyskinesis, diagnosed by the clinical observation of an expert physical therapist, using a group of healthy individuals (Type IV).Method:Twenty-six asymptomatic subjects volunteered for this study. After a fatigue protocol for the periscapular muscles, the dynamic scapular dyskinesis tests were conducted to visually classify each scapula into one of the four categories (Type IV dyskinesis-free). The kinematic variables studied were the differences between the maximum rotational dysfunctions and the minimum value that represented both normal function and a small dysfunctional movement.Results:Only scapular anterior tilt was significantly greater in the type I dyskinesis group (clinical observation of the posterior projection of the inferior angle of the scapula) when compared to the scapular dyskinesis-free group (p=0.037 scapular and p=0.001 sagittal plane).Conclusions:Clinical observation was considered appropriate only in the diagnoses of dyskinesis type I. Considering the lower prevalence and sample sizes for types II and III, further studies are necessary to validate the clinical observation as a tool to diagnose scapular dyskinesis.Contextualização:A movimentação ou posição alterada da escápula é definida como discinese escapular. O exame visual dinâmico pode ser utilizado para classificá-la de acordo com o julgamento clínico de projeção posterior excessiva da borda inferior medial (tipo I), da borda medial (tipo II) ou ainda translação excessiva no sentido cranial (tipo III).Objetivo: Determinar se há diferenças nas rotações escapulares (tipo I e II) e posição (tipo III) entre grupos de discinese e normais (tipo IV), os quais foram diagnosticados visualmente por um fisioterapeuta experiente.Método:Vinte e seis participantes assintomáticos foram voluntários neste estudo. Após um protocolo de fadiga periescapular, a avaliação dinâmica da discinese foi conduzida para classificar visualmente cada uma das escápulas em uma das quatro categorias (tipo IV - sem discinese). As variáveis cinemáticas estudadas foram a diferença entre o valor máximo indicativo da disfunção e o mínimo valor correspondente ao padrão normal esperado para o movimento ou o mínimo do próprio movimento disfuncional.Resultados:Apenas a inclinação anterior da escápula foi significantemente maior no grupo de discinese tipo I (observação visual de projeção posterior do ângulo inferior da escápula) quando comparada com o grupo sem discinese (p=0,037 plano escapular e p=0,001 plano sagital).Conclusões:A avaliação visual foi considerada apropriada apenas para o diagnóstico da discinese do tipo I. Considerando a baixa prevalência e o tamanho amostral dos tipos II e III, mais estudos são necessários para validar completamente a observação clínica como método adequado para o diagnóstico da discinese escapular.Universidade de São Paulo Ribeirao Preto Medical SchoolUniversidade Federal de São Paulo (UNIFESP) Department of Human Movement SciencesUniversity of Washington School of MedicineUNIFESP, Department of Human Movement SciencesSciEL

A combination of amino acids and caffeine enhances sprint running capacity in a hot, hypoxic environment

Heat and hypoxia exacerbate central nervous system (CNS) fatigue. We therefore investigated whether essential amino acid (EAA) and caffeine ingestion attenuates CNS fatigue in a simulated team sport–specific running protocol in a hot, hypoxic environment. Subelite male team sport athletes (n = 8) performed a repeat sprint running protocol on a nonmotorized treadmill in an extreme environment on 4 separate occasions. Participants ingested one of four supplements: a double placebo, 3 mg.kg⁻¹ body mass of caffeine + placebo, 2 × 7 g EAA (Musashi Create)+placebo, or caffeine + EAA before each exercise session using a randomized, double-blind crossover design. Electromyography (EMG) activity and quadriceps evoked responses to magnetic stimulation were assessed from the dominant leg at preexercise, halftime, and postexercise. Central activation ratio (CAR) was used to quantify completeness of quadriceps activation. Oxygenation of the prefrontal cortex was measured via near-infrared spectroscopy. Mean sprint work was higher (M = 174 J, 95% CI [23, 324], p < .05, d = 0.30; effect size, likely beneficial) in the caffeine + EAA condition versus EAAs alone. The decline in EMG activity was less (M = 13%, 95% CI [0, 26]; p < .01, d = 0.58, likely beneficial) in caffeine + EAA versus EAA alone. Similarly, the pre- to postexercise decrement in CAR was significantly less (M = −2.7%, 95% CI [0.4, 5.4]; p < .05, d = 0.50, likely beneficial) when caffeine + EAA were ingested compared with placebo. Cerebral oxygenation was lower (M = −5.6%, 95% CI [1.0, 10.1]; p < .01, d = 0.60, very likely beneficial) in the caffeine + EAA condition compared with LNAA alone. Coingestion of caffeine and EAA appears to maintain muscle activation and central drive, with a small improvement in running performance.13 page(s

Accelerated gas-liquid visible light photoredox catalysis with continuous-flow photochemical microreactors

In this protocol, we describe the construction and use of an operationally simple photochemical microreactor for gas-liquid photoredox catalysis using visible light. The general procedure includes details on how to set up the microreactor appropriately with inlets for gaseous reagents and organic starting materials, and it includes examples of how to use it to achieve continuous-flow preparation of disulfides or trifluoromethylated heterocycles and thiols. The reported photomicroreactors are modular, inexpensive and can be prepared rapidly from commercially available parts within 1 h even by nonspecialists. Interestingly, typical reaction times of gas-liquid visible light photocatalytic reactions performed in microflow are lower (in the minute range) than comparable reactions performed as a batch process (in the hour range). This can be attributed to the improved irradiation efficiency of the reaction mixture and the enhanced gas-liquid mass transfer in the segmented gas-liquid flow regime

Effects of aripiprazole once-monthly on domains of personal and social performance: Results from 2 multicenter, randomized, double-blind studies

Objective: To assess the effects of maintenance therapy with aripiprazole once-monthly 400 mg on personal and social functioning. Methods: Data were analyzed from 2 randomized, double-blind trials of patients with schizophrenia requiring chronic antipsychotic treatment. One study was a 52-week trial of aripiprazole once-monthly 400 mg versus placebo; the other was a 38-week trial of aripiprazole once-monthly 400 mg, oral aripiprazole (10-30 mg daily), and aripiprazole once-monthly 50 mg (subtherapeutic dose to test assay sensitivity). Functioning was assessed using the Personal and Social Performance (PSP) scale, comprising 4 domain subscales. Results: In the 52-week study, 403 patients stabilized on aripiprazole once-monthly 400 mg were randomized to receive aripiprazole once-monthly 400 mg (n=269) or placebo (n=134). In the 38-week study, 662 patients stabilized on oral aripiprazole were randomized to receive aripiprazole once-monthly 400 mg (n=265), oral aripiprazole (n=266), or aripiprazole once-monthly 50 mg (subtherapeutic dose; n=131). In the 52-week study, mean changes from baseline were significantly worsened with placebo compared with aripiprazole once-monthly 400 mg for PSP total score (

Efficient Photonic Integration of Diamond Color Centers and Thin-Film Lithium Niobate

On-chip photonic quantum circuits with integrated quantum memories have the potential to radically progress hardware for quantum information processing. In particular, negatively charged group-IV color centers in diamond are promising candidates for quantum memories, as they combine long storage times with excellent optical emission properties and an optically-addressable spin state. However, as a material, diamond lacks many functionalities needed to realize scalable quantum systems. Thin-film lithium niobate (TFLN), in contrast, offers a number of useful photonic nonlinearities, including the electro-optic effect, piezoelectricity, and capabilities for periodically-poled quasi-phase matching. Here, we present highly efficient heterogeneous integration of diamond nanobeams containing negatively charged silicon-vacancy (SiV) centers with TFLN waveguides. We observe greater than 90\% transmission efficiency between the diamond nanobeam and TFLN waveguide on average across multiple measurements. By comparing saturation signal levels between confocal and integrated collection, we determine a $10$-fold increase in photon counts channeled into TFLN waveguides versus that into out-of-plane collection channels. Our results constitute a key step for creating scalable integrated quantum photonic circuits that leverage the advantages of both diamond and TFLN materials