1,130 research outputs found
Robotics and AI-Enabled On-Orbit Operations With Future Generation of Small Satellites
The low-cost and short-lead time of small satellites has led to their use in science-based missions, earth observation, and interplanetary missions. Today, they are also key instruments in orchestrating technological demonstrations for On-Orbit Operations (O 3 ) such as inspection and spacecraft servicing with planned roles in active debris removal and on-orbit assembly. This paper provides an overview of the robotics and autonomous systems (RASs) technologies that enable robotic O 3 on smallsat platforms. Major RAS topics such as sensing & perception, guidance, navigation & control (GN&C) microgravity mobility and mobile manipulation, and autonomy are discussed from the perspective of relevant past and planned missions
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Uncharted Waters: Treating Trauma Symptoms in the Context of Early Psychosis.
Psychosis is conceptualized in a neurodevelopmental vulnerability-stress framework, and childhood trauma is one environmental factor that can lead to psychotic symptoms and the development of psychotic disorders. Higher rates of trauma are associated with higher psychosis risk and greater symptom frequency and severity, resulting in increased hospitalization rates and demand on outpatient primary care and mental health services. Despite an estimated 70% of individuals in the early stages of psychosis reporting a history of experiencing traumatic events, trauma effects (post-traumatic anxiety or depressive symptoms) are often overlooked in psychosis treatment and current interventions typically do not target commonly comorbid post-traumatic stress symptoms. We presented a protocol for Trauma-Integrated Cognitive Behavioral Therapy for Psychosis (TI-CBTp), an approach to treating post-traumatic stress symptoms in the context of early psychosis care. We provided a brief summary of TI-CBTp as implemented in the context of Coordinated Specialty Care and presented preliminary data supporting the use of TI-CBTp in early psychosis care. The preliminary results suggest that individuals with comorbid psychosis and post-traumatic stress symptoms can be appropriately and safely treated using TI-CBTp within Coordinated Specialty Care
Preloaded time trial to assess load carriage performance.
The relevance and importance of load carriage in recreational and occupational tasks has stimulated a large body of research. Exercise protocols have been criticized for a lack of relevance to occupational activities; accordingly, the aim of this study was to assess the reliability of a preloaded time-trial protocol for load carriage assessment. After full familiarization, 8 healthy males performed 2 trials separated by 1 week. Each trial comprised 60-minute walking at 6.5 km·h and 0% gradient (LC), 15 minutes seated recovery followed by a 2.4-km time-trial (LCTT). All trials were performed wearing a 25-kg backpack. Performance time was 16.71 ± 1.82 minutes and 16.37 ± 1.78 minutes for LCTT 1 and 2, respectively with a mean difference of -0.34 ± 0.89 minutes. Using log ratio limits of agreement, the mean bias was 1.02 and random error component of the agreement ratio was 1.11. The intraclass correlation was 0.85, coefficient of variation was 10.5%, and Cohen's d was 0.35. The protocol demonstrated a very good level of reliability. We present a novel and reliable preloaded time-trial protocol that more closely reflects operational activities and can be used to quantify load carriage performance. This protocol provides greater ecologically validity regarding physical demands of load carriage activities than those adopted previously and provides an excellent tool for the strength and conditioning practitioner to assess individual load carriage performance.N/
Effects of load mass carried in a backpack upon respiratory muscle fatigue.
The purpose of this study was to investigate whether loads carried in a backpack, with a load mass ranging from 0 to 20 kg, causes respiratory muscle fatigue. Methods: Eight males performed four randomised load carriage (LC) trials comprising 60 min walking at 6.5 km h−1 wearing a backpack of either 0 (LC0), 10 (LC10), 15 (LC15) or 20 kg (LC20). Inspiratory (PImax) and expiratory (PEmax) mouth pressures were assessed prior to and immediately following each trial. Pulmonary gas exchange, heart rate (HR), blood lactate and glucose concentration and perceptual responses were recorded during the first and final 60 s of each trial. Results: Group mean PImax and PEmax were unchanged following 60-min load carriage in all conditions (p > .05). There was an increase over time in pulmonary gas exchange, HR and perceptions of effort relative to baseline measures during each trial (p  .05). Conclusions: These findings indicate that sub-maximal walking with no load or carrying 10, 15 or 20 kg in a backpack for up to 60 min does not cause respiratory muscle fatigue despite causing an increase in physiological, metabolic and perceptual parameters.N/
Computational studies explain the importance of two different substituents on the chelating bis(amido) ligand for transfer hydrogenation by bifunctional Cp*Rh(III) catalysts
A computational approach (DFT-B3PW91) is used to address previous experimental studies (Chem. Commun. 2009, 6801) that showed that transfer hydrogenation of a cyclic imine by Et3N·HCO2H in dichloromethane catalyzed by 16-electron bifunctional Cp*Rh III(XNC6H4NX') is faster when XNC 6H4NX' = TsNC6H4NH than when XNC6H4NX' = HNC6H4NH or TsNC 6H4NTs (Cp* = η5-C5Me 5, Ts = toluenesulfonyl). The computational study also considers the role of the formate complex observed experimentally at low temperature. Using a model of the experimental complex in which Cp* is replaced by Cp and Ts by benzenesulfonyl (Bs), the calculations for the systems in gas phase reveal that dehydrogenation of formic acid generates CpRhIIIH(XNC 6H4NX'H) via an outer-sphere mechanism. The 16-electron Rh complex + formic acid are shown to be at equilibrium with the formate complex, but the latter lies outside the pathway for dehydrogenation. The calculations reproduce the experimental observation that the transfer hydrogenation reaction is fastest for the nonsymmetrically substituted complex CpRh III(XNC6H4NX') (X = Bs and X' = H). The effect of the linker between the two N atoms on the pathway is also considered. The Gibbs energy barrier for dehydrogenation of formic acid is calculated to be much lower for CpRhIII(XNCHPhCHPhNX') than for CpRh III(XNC6H4NX') for all combinations of X and X'. The energy barrier for hydrogenation of the imine by the rhodium hydride complex is much higher than the barrier for hydride transfer to the corresponding iminium ion, in agreement with mechanisms proposed for related systems on the basis of experimental data. Interpretation of the results by MO and NBO analyses shows that the most reactive catalyst for dehydrogenation of formic acid contains a localized Rh-NH π-bond that is associated with the shortest Rh-N distance in the corresponding 16-electron complex. The asymmetric complex CpRhIII(BsNC6H4NH) is shown to generate a good bifunctional catalyst for transfer hydrogenation because it combines an electrophilic metal center and a nucleophilic NH group
GJ 9404 b:A Confirmed Eccentric Planet, and not a Candidate
Eccentric orbits can be decomposed into a series of sine curves which affects
how the false alarm probability is computed when using traditional periodograms
on radial-velocity data. Here we show that a candidate exoplanet orbiting the M
dwarf GJ 9404, identified by the HADES survey using data from the HARPS-N
spectrograph, is in fact a bona-fide planet on a highly eccentric orbit. Far
from a candidate, GJ 9404 b is detected with a high confidence. We reach our
conclusion using two methods that assume Keplerian functions rather than sines
to compute a detection probability, a Bayes Factor, and the FIP periodogram. We
compute these using nested sampling with {\tt kima}.Comment: 3 pages, 1 figur
Early Psychosis and Trauma-Related Disorders: Clinical Practice Guidelines and Future Directions
Photoactivated cell-killing involving a low molecular weight, donor–acceptor diphenylacetylene
Photoactivation of photosensitisers can be utilised to elicit the production of ROS, for potential therapeutic applications, including the destruction of diseased tissues and tumours. A novel class of photosensitiser, exemplified by DC324, has been designed possessing a modular, low molecular weight and ‘drug-like’ structure which is bioavailable and can be photoactivated by UV-A/405 nm or corresponding two-photon absorption of near-IR (800 nm) light, resulting in powerful cytotoxic activity, ostensibly through the production of ROS in a cellular environment. A variety of in vitro cellular assays confirmed ROS formation and in vivo cytotoxic activity was exemplified via irradiation and subsequent targeted destruction of specific areas of a zebrafish embryo
Process-oriented approach towards catalyst design and optimisation
Translation of catalysts developed in academia to industrial end-users remains a challenge due to a lack of knowledge about the impact of catalyst attributes on the whole process and vice versa. A systematic methodology is proposed that assesses these in terms of Key Performance Indicators (KPIs). As a case study, the dehydration of butanol to butenes and dibutyl ether is considered over H-ZSM5 and H-Beta catalysts. It is demonstrated that catalysts should be designed for complete conversion and high butene selectivity, as removal of unreacted 1-butanol requires a complex separation due to the thermo-physical properties of the product mixture
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