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Functional testing is key to fulfill quality control in laptop manufacturing and is of great economic value. However, due to the unavailability of practical data, mathematical model and systematic perspective, it has barely been touched from the academic community to date. For the first time, this work provides technical understanding of the key principles of functional testing, mathematically models the general framework, elucidates existing testing strategy under the proposed framework and model, and finally proposes a specified optimization strategy which outperforms existing strategies. This work lays the model foundation for the further optimization of functional testing, and can be regarded as a good example of how a systematic approach can solve practical industrial challenges.

To achieve efficient transfer and storage of aircraft in narrow spaces, this paper proposes a multi-body cooperative omnidirectional transfer robot system. This system consists of three omnidirectional intelligent robots, enabling omnidirectional transfer of aircraft. This paper introduces the system composition, degree of freedom design, and communication between robots. It also introduces the wheel-holding mechanism and frame design, conducts structural mechanics simulation and dynamic simulation, and fabricates a prototype for functional testing. The experimental results show that the system can achieve omnidirectional transfer of aircraft, and it is safe and reliable.

In the past decades, software‐based self‐testing (SBST) which is testing of a processing core using its native instructions has attracted much attention. However, efficient SBST of a processing core which is deeply embedded in a multicore architecture is still an open issue. In this study, inspiring from built‐in self‐test methods, the authors place several number of hardware test components next to the processing cores in order to overcome existing SBST challenges. These test components facilitate quick testing of embedded cores by providing several mechanisms such as virtual fetch, virtual jump, fake load & store, and segmented test application. In order to enable segmented test application, they propose the concept of test snippet and a test snippet generation approach. The result is the capability of testing embedded cores in short idle times leading to efficient online testing of the cores with zero performance overhead. The authors’ results show that their test snippet generation approach not only leads to the production of test snippets which are properly fitted the proposed test architecture but also its final fault coverage is comparable and even a little better than the fault coverage of the best existing methods.

AimTo determine the effectiveness of functional stress testing and computed tomography angiography (CTA) for diagnosis of obstructive coronary artery disease (CAD).Methods and resultsTwo-thousand nine-hundred twenty symptomatic stable chest pain patients were included in the international Collaborative Meta-Analysis of Cardiac CT consortium to compare CTA with exercise electrocardiography (exercise-ECG) and single-photon emission computed tomography (SPECT) for diagnosis of CAD defined as ≥ 50% diameter stenosis by invasive coronary angiography (ICA) as reference standard. Generalised linear mixed models were used for calculating the diagnostic accuracy of each diagnostic test including non-diagnostic results as dependent variables in a logistic regression model with random intercepts and slopes. Covariates were the reference standard ICA, the type of diagnostic method, and their interactions. CTA showed significantly better diagnostic performance (p < 0.0001) with a sensitivity of 94.6% (95% CI 92.7–96) and a specificity of 76.3% (72.2–80) compared to exercise-ECG with 54.9% (47.9–61.7) and 60.9% (53.4–66.3), SPECT with 72.9% (65–79.6) and 44.9% (36.8–53.4), respectively. The positive predictive value of CTA was ≥ 50% in patients with a clinical pretest probability of 10% or more while this was the case for ECG and SPECT at pretest probabilities of ≥ 40 and 28%. CTA reliably excluded obstructive CAD with a post-test probability of below 15% in patients with a pretest probability of up to 74%.ConclusionIn patients with stable chest pain, CTA is more effective than functional testing for the diagnosis as well as for reliable exclusion of obstructive CAD. CTA should become widely adopted in patients with intermediate pretest probability.Systematic review registrationPROSPERO Database for Systematic Reviews—CRD42012002780.Critical relevance statementIn symptomatic stable chest pain patients, coronary CTA is more effective than functional testing for diagnosis and reliable exclusion of obstructive CAD in intermediate pretest probability of CAD.Key PointsCoronary computed tomography angiography showed significantly better diagnostic performance (p < 0.0001) for diagnosis of coronary artery disease compared to exercise-ECG and SPECT.The positive predictive value of coronary computed tomography angiography was ≥ 50% in patients with a clinical pretest probability of at least 10%, for ECG ≥ 40%, and for SPECT 28%.Coronary computed tomography angiography reliably excluded obstructive coronary artery disease with a post-test probability of below 15% in patients with a pretest probability of up to 74%.

[...]the end of the pandemic is only possible when vaccines that are effective against circulating variants are distributed equitably across the world. [...]for surveillance of the circulation of SARS-CoV-2 variants, sharing of variant-specific PCR primers could help to monitor their spread, particularly in resource-limited countries. [...]a central repository of samples of sera and cells from individuals with past infection or past immunisation with available COVID-19 vaccines should be established for seroneutralisation and cellular immunity functional testing against newly discovered variants.

Context:A Machine Learning based System (MLS) is a software system including one or more components that learn how to perform a task from a given data set. The increasing adoption of MLSs in safety critical domains such as autonomous driving, healthcare, and finance has fostered much attention towards the quality assurance of such systems. Despite the advances in software testing, MLSs bring novel and unprecedented challenges, since their behaviour is defined jointly by the code that implements them and the data used for training them.Objective:To identify the existing solutions for functional testing of MLSs, and classify them from three different perspectives: (1) the context of the problem they address, (2) their features, and (3) their empirical evaluation. To report demographic information about the ongoing research. To identify open challenges for future research.Method:We conducted a systematic mapping study about testing techniques for MLSs driven by 33 research questions. We followed existing guidelines when defining our research protocol so as to increase the repeatability and reliability of our results.Results:We identified 70 relevant primary studies, mostly published in the last years. We identified 11 problems addressed in the literature. We investigated multiple aspects of the testing approaches, such as the used/proposed adequacy criteria, the algorithms for test input generation, and the test oracles.Conclusions:The most active research areas in MLS testing address automated scenario/input generation and test oracle creation. MLS testing is a rapidly growing and developing research area, with many open challenges, such as the generation of realistic inputs and the definition of reliable evaluation metrics and benchmarks.

Hydra continually renews all cells in its body using three stem cell populations. This feature of Hydra allowed Siebert et al. to identify the transcriptional signatures of stem cells, progenitors, and terminally differentiated cells using single-cell RNA sequencing of adult Hydra (see the Perspective by Reddien). From these data, they built differentiation trajectories for all cell lineages, identified gene modules expressed along these trajectories, and identified putative regulators of genes within these modules. In addition, they identified candidate markers for elusive cell populations (such as multipotent stem cells and germline stem cells) and built a molecular map of the nervous system. Science , this issue p. eaav9314 ; see also p. 314 Single-cell sequencing of Hydra , a small freshwater cnidarian, uncovers gene expression underlying ongoing tissue homeostasis. The adult Hydra polyp continually renews all of its cells using three separate stem cell populations, but the genetic pathways enabling this homeostatic tissue maintenance are not well understood. We sequenced 24,985 Hydra single-cell transcriptomes and identified the molecular signatures of a broad spectrum of cell states, from stem cells to terminally differentiated cells. We constructed differentiation trajectories for each cell lineage and identified gene modules and putative regulators expressed along these trajectories, thus creating a comprehensive molecular map of all developmental lineages in the adult animal. In addition, we built a gene expression map of the Hydra nervous system. Our work constitutes a resource for addressing questions regarding the evolution of metazoan developmental processes and nervous system function.

Liver transplantation is a highly successful treatment, but is severely limited by the shortage in donor organs. However, many potential donor organs cannot be used; this is because sub-optimal livers do not tolerate conventional cold storage and there is no reliable way to assess organ viability preoperatively. Normothermic machine perfusion maintains the liver in a physiological state, avoids cooling and allows recovery and functional testing. Here we show that, in a randomized trial with 220 liver transplantations, compared to conventional static cold storage, normothermic preservation is associated with a 50% lower level of graft injury, measured by hepatocellular enzyme release, despite a 50% lower rate of organ discard and a 54% longer mean preservation time. There was no significant difference in bile duct complications, graft survival or survival of the patient. If translated to clinical practice, these results would have a major impact on liver transplant outcomes and waiting list mortality. Normothermic machine perfusion of the liver improved early graft function, demonstrated by reduced peak serum aspartate transaminase levels and early allograft dysfunction rates, and improved organ utilization and preservation times, although no differences were seen in graft or patient survival.

Epitranscriptomic modifications can impact behavior. Here, we used Drosophila melanogaster to study N 6 -methyladenosine (m 6 A), the most abundant modification of mRNA. Proteomic and functional analyses confirm its nuclear (Ythdc1) and cytoplasmic (Ythdf) YTH domain proteins as major m 6 A binders. Assays of short term memory in m 6 A mutants reveal neural-autonomous requirements of m 6 A writers working via Ythdf, but not Ythdc1. Furthermore, m 6 A/Ythdf operate specifically via the mushroom body, the center for associative learning. We map m 6 A from wild-type and Mettl3 mutant heads, allowing robust discrimination of Mettl3-dependent m 6 A sites that are highly enriched in 5’ UTRs. Genomic analyses indicate that Drosophila m 6 A is preferentially deposited on genes with low translational efficiency and that m 6 A does not affect RNA stability. Nevertheless, functional tests indicate a role for m 6 A/Ythdf in translational activation. Altogether, our molecular genetic analyses and tissue-specific m 6 A maps reveal selective behavioral and regulatory defects for the Drosophila Mettl3/Ythdf pathway. Epitranscriptomic modifications can regulate learning and memory. Here, the authors provide proteomic and functional analysis of N6-methyladenosine (m 6 A)-binding proteins in D. melanogaster and unveil behavioral and regulatory defects for m6A/Ythdf mutants.

With the constant evolution of substation (converter) station towards high capacity, high voltage level, and high-efficiency operation, in the process of construction and operation and maintenance of substation (converter) station, in order to improve operation efficiency and ensure personnel safety, based on finite element analysis and calculation, a crawler-type multifunction integrated boom transport vehicle is designed and developed. The integrated boom adopts a four-stage retractable design, and implements multi-port matching planning at the end, which can adapt three kinds of mechanical modules, such as lifting, manned, and gripper. The design of the whole vehicle is described in detail from three dimensions: mechanical, electrical, and hydraulic. Finally, the functional test and practical application of the developed integrated boom transport vehicle were carried out in a substation (converter) station. The results show that the crawler body chassis can be turned in place, the mechanical gripper module can grasp the equipment support with a diameter of 300 mm, a weight of 200-300 kg, and a length of 4.5 m, and the minimum length of the steel pipe is 3800 mm. The manned platform has a maximum load of 200 kg and a maximum height of 6 m for installation.