Attitude Sensor Pseudonoise

Even assuming perfect attitude sensors and gyros, sensor measurements on a vibrating spacecraft have apparent errors. These apparent sensor errors, referred to as pseudonoise, arise because gyro and sensor measurements are performed at discrete times. This paper explains the concept of pseudonoise, quantifies its behavior, and discusses the effect of vibrations that are nearly commensurate with measurement periods. Although pseudonoise does not usually affect attitude determination it does affect sensor performance evaluation. Attitude rates are usually computed from differences between pairs of accumulated angle measurements at different times and are considered constant in the periods between measurements. Propagation using these rates does not reproduce exact instantaneous spacecraft attitudes except at the gyro measurement times. Exact sensor measurements will therefore be inconsistent with estimates based on the propagated attitude. This inconsistency produces pseudonoise. The characteristics of pseudonoise were determined using a simple, one-dimensional model of spacecraft vibration. The statistical properties of the deviations of measurements from model truth were determined using this model and a range of different periods of sensor and rate measurements. This analysis indicates that the magnitude of pseudonoise depends on the ratio of the spacecraft vibration period to the time between gyro measurements and can be as much as twice the amplitude of the vibration. In cases where the vibration period and gyro or sensor measurement period are nearly commensurate, unexpected changes in pseudonoise occur

Aristotle's Peculiarly Human Psychology

For Aristotle, human cognition has a lot in common both with non-human animal cognition and with divine cognition. With non-human animals, humans share a non-rational part of the soul and non-rational cognitive faculties (DA 427b6–14, NE 1102b29 and EE 1219b24–6). With gods, humans share a rational part of the soul and rational cognitive faculties (NE 1177b17– 1178a8). The rational part and the non-rational part of the soul, however, coexist and cooperate only in human souls (NE 1102b26–9, EE 1219b28–31). In this chapter, I show that a study of this cooperation helps to uncover some distinctive aspects of human cognition and desire

Testing a model of antecedents and consequences of defensive pessimism and self-handicapping in school physical education

There has been very limited research on the use of self-worth protection strategies in the achievement context of school physical education (PE). Thus, this study aimed to examine some antecedents and consequences of defensive pessimism and self-handicapping. The sample comprised 534 (females n = 275; males n = 259) British pupils recruited from two schools who responded to established questionnaires. Results of structural equation modelling analysis indicated that self-handicapping and defensive pessimism were positively predicted by fear of failure and negatively predicted by competence valuation. In addition, defensive pessimism was negatively predicted by physical self-concept. In turn, defensive pessimism negatively predicted enjoyment in PE and intentions to participate in future optional PE programs. Self-handicapping did not predict enjoyment or intentions. Results from multi-sample structural equation modelling showed the specified model to be largely invariant across males and females. The findings indicate that although both strategies aim to protect one’s self-worth, some of their antecedents and consequences in PE may differ

Prospects for the future of pink salmon in three oceans: From the native Pacific to the novel Arctic and Atlantic

While populations of other migratory salmonids suffer in the Anthropocene, pink salmon (Oncorhynchus gorbusca Salmonidae) are thriving, and their distribution is expanding both within their natural range and in the Atlantic and Arctic following introduction of the species to the White Sea in the 1950s. Pink salmon are now rapidly spreading in Europe and even across the ocean to North America. Large numbers of pink salmon breed in Norwegian rivers and small numbers of individuals have been captured throughout the North Atlantic since 2017. Although little is known about the biology and ecology of the pink salmon in its novel distribution, the impacts of the species' introduction are potentially highly significant for native species and watershed productivity. Contrasts between pink salmon in the native and extended ranges will be key to navigating management strategies for Atlantic nations where the pink salmon is entrenching itself among the fish fauna, posing potential threats to native fish communities. One key conclusion of this paper is that the species' heritable traits are rapidly selected and drive local adaptation and evolution. Within the Atlantic region, this may facilitate further establishment and spread. The invasion of pink salmon in the Atlantic basin is ultimately a massive ecological experiment and one of the first examples of a major faunal change in the North Atlantic Ocean that is already undergoing rapid changes due to other anthropogenic stressors. New research is urgently needed to understand the role and potential future impacts of pink salmon in Atlantic ecosystems. Atlantification, biological invasions, climate adaptation, Pacific Ocean, regime shiftpublishedVersio

Assessing the risk of stress in organizations:Getting the measure of organizational-level stressors

Great Britain’s Health and Safety Executive (HSE) developed the Management Standards Indicator Tool to help organizations to assess and monitor organizational risks of work-related stress through surveying employees about the psychosocial risks for stress in their jobs. The use of employee-level data for deriving an organizational-level measure of psychosocial risks assumes that the constructs have equivalent meanings at different levels. However, this isomorphic condition has never been tested and this study fills this gap. Using data collected by the Italian Workers’ Compensation Authority (INAIL) from 66,188 employees nested in 775 organizations, we demonstrate that the organizational-level measure representing the seven dimensions of the Management Standards Indicator Tool is equivalent, though not identical, to the individual-level measure. This implies that the organizational level is not a mirror of the aggregation of the individual level, and that the risk of work-related stress in an organization may derive not simply from bottom-up processes, but may be generated by top-down influences (e.g., organizational policies). Interventions may then be meaningfully targeted at the organizational level in the expectation that they will reduce the risk of work-related stress among the entire workforce, the valid measurement of which can be performed through the HSE’s Management Standards Indicator Tool

ABL1, Overexpressed in Hepatocellular Carcinomas, Regulates Expression of NOTCH1 and Promotes Development of Liver Tumors in Mice

Background & Aims We investigated whether ABL proto-oncogene 1, non-receptor tyrosine kinase (ABL1) is involved in development of hepatocellular carcinoma (HCC). Methods We analyzed clinical and gene expression data from The Cancer Genome Atlas. Albumin-Cre (HepWT) mice and mice with hepatocyte-specific disruption of Abl1 (HepAbl–/– mice) were given hydrodynamic injections of plasmids encoding the Sleeping Beauty transposase and transposons with the MET gene and a catenin β1 gene with an N-terminal truncation, which induces development of liver tumors. Some mice were then gavaged with the ABL1 inhibitor nilotinib or vehicle (control) daily for 4 weeks. We knocked down ABL1 with short hairpin RNAs in Hep3B and Huh7 HCC cells and analyzed their proliferation and growth as xenograft tumors in mice. We performed RNA sequencing and gene set enrichment analysis of tumors. We knocked down or overexpressed NOTCH1 and MYC in HCC cells and analyzed proliferation. We measured levels of phosphorylated ABL1, MYC, and NOTCH1 by immunohistochemical analysis of an HCC tissue microarray. Results HCC tissues had higher levels of ABL1 than non-tumor liver tissues, which correlated with shorter survival times of patients. HepWT mice with the MET and catenin β1 transposons developed liver tumors and survived a median 64 days; HepAbl–/– mice with these transposons developed tumors that were 50% smaller and survived a median 81 days. Knockdown of ABL1 in human HCC cells reduced proliferation, growth as xenograft tumors in mice, and expression of MYC, which reduced expression of NOTCH1. Knockdown of NOTCH1 or MYC in HCC cells significantly reduced cell growth. NOTCH1 or MYC overexpression in human HCC cells promoted proliferation and rescued the phenotype caused by ABL1 knockdown. The level of phosphorylated (activated) ABL1 correlated with levels of MYC and NOTCH1 in human HCC specimens. Nilotinib decreased expression of MYC and NOTCH1 in HCC cell lines, reduced the growth of xenograft tumors in mice, and slowed growth of liver tumors in mice with MET and catenin β1 transposons, reducing tumor levels of MYC and NOTCH1. Conclusions HCC samples have increased levels of ABL1 compared with nontumor liver tissues, and increased levels of ABL1 correlate with shorter survival times of patients. Loss or inhibition of ABL1 reduces proliferation of HCC cells and slows growth of liver tumors in mice. Inhibitors of ABL1 might be used for treatment of HCC

Vega—A small, low cost, ground robot for nuclear decommissioning

From Wiley via Jisc Publications RouterHistory: received 2021-08-20, rev-recd 2021-11-03, accepted 2021-11-05, pub-electronic 2021-11-25Article version: VoRPublication status: PublishedFunder: Royal Academy of Engineering; Id: http://dx.doi.org/10.13039/501100000287Funder: Engineering and Physical Sciences Research Council; Id: http://dx.doi.org/10.13039/501100000266Abstract: This paper presents the Vega robot, which is a small, low cost, potentially disposable ground robot designed for nuclear decommissioning. Vega has been developed specifically to support characterization and inspection operations, such as 2D and 3D mapping, radiation scans and sample retrieval. The design and construction methodology that was followed to develop the robot is described and its capabilities detailed. Vega was designed to provide flexibility, both in software and hardware, is controlled via tele‐operation, although it can be extended to semi and full autonomy, and can be used in either tethered or untethered configurations. A version of the tethered robot was designed for extreme radiation tolerance, utilizing relay electronics and removing active electronic systems. Vega can be outfitted with a multitude of sensors and actuators, including gamma spectrometers, alpha/beta radiation sensors, LiDARs and robotic arms. To demonstrate its flexibility, a 5 degree‐of‐freedom manipulator has been successfully integrated onto Vega, facilitating deployments where handling is required. To assess the tolerance of Vega to the levels of ionizing radiation that may be found in decommissioning environments, its individual components were irradiated, allowing estimates to be made of the length of time Vega would be able to continue to operate in nuclear environments. Vega has been successfully deployed in an active environment at the Dounreay nuclear site in the UK, deployed in nonactive environments at the Atomic Weapons Establishment, and demonstrated to many other organizations in the UK nuclear industry including Sellafield Ltd, with the goal of moving to active deployments in the future

Intramolecular Epistasis and the Evolution of a New Enzymatic Function

Atrazine chlorohydrolase (AtzA) and its close relative melamine deaminase (TriA) differ by just nine amino acid substitutions but have distinct catalytic activities. Together, they offer an informative model system to study the molecular processes that underpin the emergence of new enzymatic function. Here we have constructed the potential evolutionary trajectories between AtzA and TriA, and characterized the catalytic activities and biophysical properties of the intermediates along those trajectories. The order in which the nine amino acid substitutions that separate the enzymes could be introduced to either enzyme, while maintaining significant catalytic activity, was dictated by epistatic interactions, principally between three amino acids within the active site: namely, S331C, N328D and F84L. The mechanistic basis for the epistatic relationships is consistent with a model for the catalytic mechanisms in which protonation is required for hydrolysis of melamine, but not atrazine

The role of irritability in the relation between job stressors, emotional reactivity, and counterproductive work behaviour

Researchers have stressed the importance of assessing individual differences in personality as an approach to understanding aggressive and deviant conduct across different contexts. This study investigated the moderation role of irritability, a specific aggression-related disposition, in the process of work stressors that are conducive to counterproductive work behaviour (CWB) within the stressor–emotion model. From a total sample of 1147 Italian workers (53.5% women), high- and low-irritability groups were identified. Then, using a multigroup structural equations model, we simultaneously examined all the relations in both high- and low-irritability groups, and investigated whether these relations were different between them. Results showed that job stressors elicited negative emotions that, in turn, lead to CWB. Moreover, some job stressors influenced CWB directly only in the high-irritability group. Overall, irritability moderated the relation among job stressors and CWB but not the relation among job stressors and negative emotions, with the sole exception of role conflict. As well, irritability did not moderate the relation between emotion and CWB. Thus, high-irritability employees may be more prone to react aggressively to job stressors via multiple functioning paths. The principal differences between low- and high-irritability individuals could be how they manage the impact of perceived stressors on emotions and behaviour