838 research outputs found
A Design Engineering Approach for Quantitatively Exploring Context-Aware Sentence Retrieval for Nonspeaking Individuals with Motor Disabilities
Nonspeaking individuals with motor disabilities typically have
very low communication rates. This paper proposes a design
engineering approach for quantitatively exploring contextaware
sentence retrieval as a promising complementary input
interface, working in tandem with a word-prediction keyboard.
We motivate the need for complementary design engineering
methodology in the design of augmentative and alternative
communication and explain how such methods can be used to
gain additional design insights. We then study the theoretical
performance envelopes of a context-aware sentence retrieval
system, identifying potential keystroke savings as a function of
the parameters of the subsystems, such as the accuracy of the
underlying auto-complete word prediction algorithm and the
accuracy of sensed context information under varying assumptions.
We find that context-aware sentence retrieval has the
potential to provide users with considerable improvements in
keystroke savings under reasonable parameter assumptions of
the underlying subsystems. This highlights how complementary
design engineering methods can reveal additional insights
into design for augmentative and alternative communication
Emerging technologies in physics education
Three emerging technologies in physics education are evaluated from the
interdisciplinary perspective of cognitive science and physics education
research. The technologies - Physlet Physics, the Andes Intelligent Tutoring
System (ITS), and Microcomputer-Based Laboratory (MBL) Tools - are assessed
particularly in terms of their potential at promoting conceptual change,
developing expert-like problem-solving skills, and achieving the goals of the
traditional physics laboratory. Pedagogical methods to maximize the potential
of each educational technology are suggested.Comment: Accepted for publication in the Journal of Science Education and
Technology; 20 page
Study of Coxsackie B viruses interactions with Coxsackie Adenovirus receptor and Decay-Accelerating Factor using Human CaCo-2 cell line
A RT-qPCR system using a degenerate probe for specific identification and differentiation of SARS-CoV-2 Omicron (B.1.1.529) variants of concern
Fast surveillance strategies are needed to control the spread of new emerging SARS-CoV-2 variants and gain time for evaluation of their pathogenic potential. This was essential for the Omicron variant (B.1.1.529) that replaced the Delta variant (B.1.617.2) and is currently the dominant SARS-CoV-2 variant circulating worldwide. RT-qPCR strategies complement whole genome sequencing, especially in resource lean countries, but mutations in the targeting primer and probe sequences of new emerging variants can lead to a failure of the existing RT-qPCRs. Here, we introduced an RT-qPCR platform for detecting the Delta- and the Omicron variant simultaneously using a degenerate probe targeting the key ΔH69/V70 mutation in the spike protein. By inclusion of the L452R mutation into the RT-qPCR platform, we could detect not only the Delta and the Omicron variants, but also the Omicron sub-lineages BA.1, BA.2 and BA.4/BA.5. The RT-qPCR platform was validated in small- and large-scale. It can easily be incorporated for continued monitoring of Omicron sub-lineages, and offers a fast adaption strategy of existing RT-qPCRs to detect new emerging SARS-CoV-2 variants using degenerate probes.</p
SecM-Stalled Ribosomes Adopt an Altered Geometry at the Peptidyl Transferase Center
A structure of a ribosome stalled during translation of the SecM peptide provides insight into the mechanism by which the large subunit active site is inactivated
Laser calibration of the ATLAS Tile Calorimeter during LHC Run 2
This article reports the laser calibration of the hadronic Tile Calorimeter
of the ATLAS experiment in the LHC Run 2 data campaign. The upgraded Laser II
calibration system is described. The system was commissioned during the first
LHC Long Shutdown, exhibiting a stability better than 0.8% for the laser light
monitoring. The methods employed to derive the detector calibration factors
with data from the laser calibration runs are also detailed. These allowed to
correct for the response fluctuations of the 9852 photomultiplier tubes of the
Tile Calorimeter with a total uncertainty of 0.5% plus a luminosity-dependent
sub-dominant term. Finally, we report the regular monitoring and performance
studies using laser events in both standalone runs and during proton
collisions. These studies include channel timing and quality inspection, and
photomultiplier linearity and response dependence on anode current
Defective Interfering Viral Particles in Acute Dengue Infections
While much of the genetic variation in RNA viruses arises because of the error-prone nature of their RNA-dependent RNA polymerases, much larger changes may occur as a result of recombination. An extreme example of genetic change is found in defective interfering (DI) viral particles, where large sections of the genome of a parental virus have been deleted and the residual sub-genome fragment is replicated by complementation by co-infecting functional viruses. While most reports of DI particles have referred to studies in vitro, there is some evidence for the presence of DI particles in chronic viral infections in vivo. In this study, short fragments of dengue virus (DENV) RNA containing only key regulatory elements at the 3′ and 5′ ends of the genome were recovered from the sera of patients infected with any of the four DENV serotypes. Identical RNA fragments were detected in the supernatant from cultures of Aedes mosquito cells that were infected by the addition of sera from dengue patients, suggesting that the sub-genomic RNA might be transmitted between human and mosquito hosts in defective interfering (DI) viral particles. In vitro transcribed sub-genomic RNA corresponding to that detected in vivo could be packaged in virus like particles in the presence of wild type virus and transmitted for at least three passages in cell culture. DENV preparations enriched for these putative DI particles reduced the yield of wild type dengue virus following co-infections of C6–36 cells. This is the first report of DI particles in an acute arboviral infection in nature. The internal genomic deletions described here are the most extensive defects observed in DENV and may be part of a much broader disease attenuating process that is mediated by defective viruses
Assessing the acceptability and feasibility of encounter decision aids for early stage breast cancer targeted at underserved patients
Six RNA Viruses and Forty-One Hosts: Viral Small RNAs and Modulation of Small RNA Repertoires in Vertebrate and Invertebrate Systems
We have used multiplexed high-throughput sequencing to characterize changes in small RNA populations that occur during viral infection in animal cells. Small RNA-based mechanisms such as RNA interference (RNAi) have been shown in plant and invertebrate systems to play a key role in host responses to viral infection. Although homologs of the key RNAi effector pathways are present in mammalian cells, and can launch an RNAi-mediated degradation of experimentally targeted mRNAs, any role for such responses in mammalian host-virus interactions remains to be characterized. Six different viruses were examined in 41 experimentally susceptible and resistant host systems. We identified virus-derived small RNAs (vsRNAs) from all six viruses, with total abundance varying from “vanishingly rare” (less than 0.1% of cellular small RNA) to highly abundant (comparable to abundant micro-RNAs “miRNAs”). In addition to the appearance of vsRNAs during infection, we saw a number of specific changes in host miRNA profiles. For several infection models investigated in more detail, the RNAi and Interferon pathways modulated the abundance of vsRNAs. We also found evidence for populations of vsRNAs that exist as duplexed siRNAs with zero to three nucleotide 3′ overhangs. Using populations of cells carrying a Hepatitis C replicon, we observed strand-selective loading of siRNAs onto Argonaute complexes. These experiments define vsRNAs as one possible component of the interplay between animal viruses and their hosts
Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector
A search for nonresonant Higgs boson pair production in the b
¯bγγ fnal state
is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV
recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes
and expands upon the previous nonresonant ATLAS results in this fnal state based on the
same data sample. The analysis strategy is optimised to probe anomalous values not only of
the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z)
coupling modifer κ2V . No signifcant excess above the expected background from Standard
Model processes is observed. An observed upper limit µHH < 4.0 is set at 95% confdence
level on the Higgs boson pair production cross-section normalised to its Standard Model
prediction. The 95% confdence intervals for the coupling modifers are −1.4 < κλ < 6.9 and
−0.5 < κ2V < 2.7, assuming all other Higgs boson couplings except the one under study are
fxed to the Standard Model predictions. The results are interpreted in the Standard Model
efective feld theory and Higgs efective feld theory frameworks in terms of constraints on
the couplings of anomalous Higgs boson (self-)interactions
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