125 research outputs found
Synthesis and superstructural characterization of Fe1.89Mo4.11O7
Superstructuring in the new compound Fe1.89Mo4.11O7 has been elucidated by transmission electron microscopy. This compound is a member of the family M2MO4O7 and has both iron and molybdenum atoms occupying octahedrally coordinated sites in the structure, represented by Fet(Fe0.89M0.11)0Mo4O7. The superstructuring, detected only by electron diffraction, involved tripling of all three lattice parameters of the subcell. The subcell was structured by single crystal x-ray diffraction [Imma, no. 74, a = 5.9793(5) Ã…, b = 5.7704(4) Ã…, and c = 17.036(1) Ã…]. This structure type contains a close-packed arrangement of Mo4O7 units, which are infinite chains of trans edge-shared molybdenum octahedra running parallel to b*. Two different coordination environments are observed for the cations. Parallel to the a* direction, infinite edge-sharing MO6 (M = 89% Fe or 11% Mo) octahedra are observed. The second cation site, with nearly tetrahedral coordination by oxygen, is filled solely by iron. The superstructure can be rationalized by a regular arrangement of iron and molybdenum atoms in the octahedrally coordinated cation sites
An Examination of the Efficacy of a Brief Educational Program on Driver Distraction
A study examined the influence of a brief educational intervention on self-reports of past and intended future distracted driving behavior, and on perception of the danger of various driver distractions (e.g. map reading, grooming, etc). Respondents completed a series of rating scales, reporting (A) the frequency with which they had participated in various distracting activities while driving in the past, (B) the frequency with which they expected to participate in those activities in the future, and (C) the perceived danger of those activities. Half of the respondents completed the rating scales after first watching a series short animated videos from the driver education program. The remaining respondents (controls) completed the surveys prior to viewing the video segments. As compared to the control subjects, participants who viewed the video segments prior to filling out the rating scales reported reliably higher levels of perceived danger for a number of distracting activities. Video segments did not, however, appear to affect respondents’ anticipated future behavior
Sustainable Human Presence on the Moon using In Situ Resources
New capabilities, technologies and infrastructure must be developed to enable a sustained human presence on the moon and beyond. The key to having this permanent presence is the utilization of in situ resources. To this end, NASA is investigating how in situ resources can be utilized to improve mission success by reducing up-mass, improving safety, reducing risk, and bringing down costs for the overall mission. To ensure that this capability is available when needed, technology development is required now. NASA/Marshall Space Flight Center (MSFC) is supporting this endeavor, along with other NASA centers, by exploring how lunar regolith can be mined for uses such as construction, life support, propulsion, power, and fabrication. Efforts at MSFC include development of lunar regolith simulant for hardware testing and development, extraction of oxygen and other materials from the lunar regolith, production of parts and tools on the moon from local materials or from provisioned feedstocks, and capabilities to show that produced parts are "ready for use". This paper discusses the lunar regolith, how the regolith is being replicated in the development of simulants and possible uses of the regolith
PrimeQA: The Prime Repository for State-of-the-Art Multilingual Question Answering Research and Development
The field of Question Answering (QA) has made remarkable progress in recent
years, thanks to the advent of large pre-trained language models, newer
realistic benchmark datasets with leaderboards, and novel algorithms for key
components such as retrievers and readers. In this paper, we introduce PRIMEQA:
a one-stop and open-source QA repository with an aim to democratize QA
re-search and facilitate easy replication of state-of-the-art (SOTA) QA
methods. PRIMEQA supports core QA functionalities like retrieval and reading
comprehension as well as auxiliary capabilities such as question generation.It
has been designed as an end-to-end toolkit for various use cases: building
front-end applications, replicating SOTA methods on pub-lic benchmarks, and
expanding pre-existing methods. PRIMEQA is available at :
https://github.com/primeqa
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ERP abnormalities during semantic processing in schizophrenia
To examine the neurophysiological and cognitive characteristics of thought disturbance in schizophrenic patients, we examined the amplitude, latency, and topography of a specific event-related brain potential (ERP), the N400, which is elicited by semantically incongruent words and phrases. Twelve chronic schizophrenic patients and twelve age-matched control subjects read sentences presented visually that had either semantically correct (e.g., ‘People pray in their local church’) or incorrect endings (e.g., ‘Every Sunday morning people pray in their local nest’). Relative to normal controls, schizophrenic patients had significantly reduced N400 amplitude and increased latency to semantically anomalous endings. Additionally, a late positive component which follows the N400 was significantly reduced in amplitude in schizophrenic patients. However, patients and controls did not differ significantly in terms of the topographical distribution of either the N400 or its late positive potential, examined at 28 electrode sites. Thus, N400 topography in schizophrenic patients was not accompanied by the asymmetry which frequently characterizes the well known auditory P300 disturbance in schizophrenic patients. We concluded that these findings may reflect a profound disturbance in attentional processes in chronic schizophrenia
The TechQA Dataset
We introduce TechQA, a domain-adaptation question answering dataset for the
technical support domain. The TechQA corpus highlights two real-world issues
from the automated customer support domain. First, it contains actual questions
posed by users on a technical forum, rather than questions generated
specifically for a competition or a task. Second, it has a real-world size --
600 training, 310 dev, and 490 evaluation question/answer pairs -- thus
reflecting the cost of creating large labeled datasets with actual data.
Consequently, TechQA is meant to stimulate research in domain adaptation rather
than being a resource to build QA systems from scratch. The dataset was
obtained by crawling the IBM Developer and IBM DeveloperWorks forums for
questions with accepted answers that appear in a published IBM Technote---a
technical document that addresses a specific technical issue. We also release a
collection of the 801,998 publicly available Technotes as of April 4, 2019 as a
companion resource that might be used for pretraining, to learn representations
of the IT domain language.Comment: Long version of conference paper to be submitte
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Magnetic resonance imaging study of hippocampal volume in chronic, combat-related posttraumatic stress disorder
This study used quantitative volumetric magnetic resonance imaging techniques to explore the neuroanatomic correlates of chronic, combat-related posttraumatic stress disorder (PTSD) in seven Vietnam veterans with PTSD compared with seven nonPTSD combat veterans and eight normal nonveterans. Both left and right hippocampi were significantly smaller in the PTSD subjects compared to the Combat Control and Normal subjects, even after adjusting for age, whole brain volume, and lifetime alcohol consumption. There were no statistically significant group differences in intracranial cavity, whole brain, ventricles, ventricle:brain ratio, or amygdala. Subarachnoidal cerebrospinal fluid was increased in both veteran groups. Our finding of decreased hippocampal volume in PTSD subjects is consistent with results of other investigations which utilized only trauma-unexposed control groups. Hippocampal volume was directly correlated with combat exposure, which suggests that traumatic stress may damage the hippocampus. Alternatively, smaller hippocampi volume may be a pre-existing risk factor for combat exposure and/or the development of PTSD upon combat exposure
Evidence for Genetic Overlap Between Schizophrenia and Age at First Birth in Women
IMPORTANCE: A recently published study of national data by McGrath et al in 2014 showed increased risk of schizophrenia (SCZ) in offspring associated with both early and delayed parental age, consistent with a U-shaped relationship. However, it remains unclear if the risk to the child is due to psychosocial factors associated with parental age or if those at higher risk for SCZ tend to have children at an earlier or later age. OBJECTIVE: To determine if there is a genetic association between SCZ and age at first birth (AFB) using genetically informative but independently ascertained data sets. DESIGN, SETTING, AND PARTICIPANTS: This investigation used multiple independent genome-wide association study data sets. The SCZ sample comprised 18 957 SCZ cases and 22 673 controls in a genome-wide association study from the second phase of the Psychiatric Genomics Consortium, and the AFB sample comprised 12 247 genotyped women measured for AFB from the following 4 community cohorts: Estonia (Estonian Genome Center Biobank, University of Tartu), the Netherlands (LifeLines Cohort Study), Sweden (Swedish Twin Registry), and the United Kingdom (TwinsUK). Schizophrenia genetic risk for each woman in the AFB community sample was estimated using genetic effects inferred from the SCZ genome-wide association study. MAIN OUTCOMES AND MEASURES: We tested if SCZ genetic risk was a significant predictor of response variables based on published polynomial functions that described the relationship between maternal age and SCZ risk in offspring in Denmark. We substituted AFB for maternal age in these functions, one of which was corrected for the age of the father, and found that the fit was superior for the model without adjustment for the father's age. RESULTS: We observed a U-shaped relationship between SCZ risk and AFB in the community cohorts, consistent with the previously reported relationship between SCZ risk in offspring and maternal age when not adjusted for the age of the father. We confirmed that SCZ risk profile scores significantly predicted the response variables (coefficient of determination R2 = 1.1E-03, P = 4.1E-04), reflecting the published relationship between maternal age and SCZ risk in offspring by McGrath et al in 2014. CONCLUSIONS AND RELEVANCE: This study provides evidence for a significant overlap between genetic factors associated with risk of SCZ and genetic factors associated with AFB. It has been reported that SCZ risk associated with increased maternal age is explained by the age of the father and that de novo mutations that occur more frequently in the germline of older men are the underlying causal mechanism. This explanation may need to be revised if, as suggested herein and if replicated in future studies, there is also increased genetic risk of SCZ in older mothers
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