961 research outputs found
Semantic Transformation of Web Services
Web services have become the predominant paradigm for the development of distributed software systems. Web services provide the means to modularize software in a way that functionality can be described, discovered and deployed in a platform independent manner over a network (e.g., intranets, extranets and the Internet). The representation of web services by current industrial practice is predominantly syntactic in nature lacking the fundamental semantic underpinnings required to fulfill the goals of the emerging Semantic Web. This paper proposes a framework aimed at (1) modeling the semantics of syntactically defined web services through a process of interpretation, (2) scop-ing the derived concepts within domain ontologies, and (3) harmonizing the semantic web services with the domain ontologies. The framework was vali-dated through its application to web services developed for a large financial system. The worked example presented in this paper is extracted from the se-mantic modeling of these financial web services
The origin of the excess transit absorption in the HD 189733 system: planet or star?
We have detected excess absorption in the emission cores of Ca II H&K during transits of HD 189733b for the first time. Using observations of three transits, we investigate the origin of the absorption, which is also seen in Hα and the Na I D lines. Applying differential spectrophotometry methods to the Ca II H and Ca II K lines combined, using respective passband widths of Δλ = 0.4 and 0.6 Å yields excess absorption of td = 0.0074 ± 0.0044 (1.7σ; Transit 1) and 0.0214 ± 0.0022 (9.8σ; Transit 2). Similarly, we detect excess Hα absorption in a passband of width Δλ = 0.7 Å, with td = 0.0084 ± 0.0016 (5.2σ) and 0.0121 ± 0.0012 (9.9σ). For both lines, Transit 2 is thus significantly deeper. Combining all three transits for the Na I D lines yields excess absorption of td = 0.0041 ± 0.0006 (6.5σ). By considering the time series observations of each line, we find that the excess apparent absorption is best recovered in the stellar reference frame. These findings lead us to postulate that the main contribution to the excess transit absorption in the differential light curves arises because the normalizing continuum bands form in the photosphere, whereas the line cores contain a chromospheric component. We cannot rule out that part of the excess absorption signature arises from the planetary atmosphere, but we present evidence which casts doubt on recent claims to have detected wind motions in the planet's atmosphere in these data
Degradation of Airway Secretory Cell Mucin Granules Is Dependent on Lysosome Activity
Inflammatory airway diseases (e.g. COPD and asthma) are associated with mucous cell metaplasia and mucin hypersecretion, resulting in symptoms such as shortness of breath and cough. However, how secretory cells remove excess mucin granules is poorly understood. Previous research suggests that intracellular degradation pathways, such as autophagy, are involved in the degradation of mucin granules during resolution of mucous cell metaplasia. We thus hypothesized that the elimination of excess mucin granules is dependent on lysosome-mediated degradation in airway secretory cells. Calu-3 cells, an airway epithelial cell line containing abundant mucin granules, were treated with inhibitors of lysosome acidification (Bafilomycin A1) and lysosome enzyme activity (Pepstatin E64d). We found statistically significant increases in the levels of secretory mucin, MUC5AC, by mucin blot, suggesting that the lysosome mediates the elimination of mucin granules. In addition, by immunoblot we observed an increase in the autophagosome markers, LC3-II and SQSTM1, with lysosome inhibition using Bafilomycin A1, indicating an accumulation of autophagosomes and a role for autophagy in the degradation of mucin granules. However, after transfecting Calu-3 cells with a ubiquitin-hemagglutinin tag plasmid to examine the role of the proteasome in the degradation of mucin granules, we observed that our transfection efficiency was low, making it difficult to detect the hemagglutinin epitope by immunoblots. Nevertheless, we found that MUC5AC levels preliminarily increase with the inhibition of the proteasome using MG-132, suggesting a potential role for the proteasome in the degradation of mucin granules. Thus, we can conclude that inhibition of the lysosome increases MUC5AC levels, demonstrating that the lysosome mediates the degradation of mucin granules in airway secretory cells. In addition, while we were not able to conclude that the proteasome is involved in the degradation of mucin granules with certainty, our preliminary data suggests that it is possible that the ubiquitin-proteasome system is involved in the degradation of mucin due to the observed increase in MUC5AC levels with MG-132.https://digitalcommons.unmc.edu/surp2022/1039/thumbnail.jp
SALT observations of the Chromospheric Activity of Transiting Planet Hosts: Mass Loss and Star Planet Interactions
We measured the chromospheric activity of the four hot Jupiter hosts WASP-43, WASP-51/HAT-P-30, WASP-72 & WASP-103 to search for anomalous values caused by the close-in companions. The Mount Wilson Ca II H&K S-index was calculated for each star using observations taken with the Robert Stobie Spectrograph at the Southern African Large Telescope. The activity level of WASP-43 is anomalously high relative to its age and falls among the highest values of all known main sequence stars. We found marginal evidence that the activity of WASP-103 is also higher than expected from the system age. We suggest that for WASP-43 and WASP-103 star-planet interactions (SPI) may enhance the Ca II H&K core emission. The activity levels of WASP-51/HAT-P-30 and WASP-72 are anomalously low, with the latter falling below the basal envelope for both main sequence and evolved stars. This can be attributed to circumstellar absorption due to planetary mass loss, though absorption in the ISM may contribute. A quarter of known short period planet hosts exhibit anomalously low activity levels, including systems with hot Jupiters and low mass companions. Since SPI can elevate and absorption can suppress the observed chromospheric activity of stars with close-in planets, their Ca II H&K activity levels are an unreliable age indicator. Systems where the activity is depressed by absorption from planetary mass loss are key targets for examining planet compositions through transmission spectroscopy
A Multispecies Monitoring Approach for Mesocarivores in the US Northern Rockies
Mesocarnivores are ecologically important species that are wide-ranging and often difficult to detect. Fisher (Pekania pennanti), lynx (Lynx canadensis), and wolverine (Gulo gulo) (hereafter mesocarnivores) are three mesocarnivores of conservation or management concern native to the US northern Rocky Mountain region (NRM). Federal and state managing agencies in NRM have multiple directives that guide management of these species and their habitats. Fulfilling these mandates is complicated by two overarching problems: 1)gaps in knowledge about the basic distribution, habitat requirements, and spatial and population trends of these mesocarnivores in the region; and 2) the lack of an appropriate, multi-scale framework to analyze the short-term and long-term trends of these species. In response, the USFS is developing a comprehensive mesocarnivore monitoring strategy to meet our mandates for the NRM. These ideas will ultimately be merged with those of our partners. We present the initial phase of this monitoring strategy, a sequential hierarchy that links the following questions to geographic locations: 1) is the species present? 2) are multiple individuals and females present? 3) how many are present? These questions were developed based on a series of structured interviews, as well as past local and regional survey and monitoring efforts for these mesocarnivores. Repeated investigations of these questions over time will allow understanding of changes in distribution and populations of these mesocarnivores in the NRM.
Fixed Base Modal Testing Using the NASA GRC Mechanical Vibration Facility
The Space Power Facility at NASA's Plum Brook Station houses the world's largest and most powerful space environment simulation facilities, including the Mechanical Vibration Facility (MVF), which offers the world's highest-capacity multi-axis spacecraft shaker system. The MVF was designed to perform sine vibration testing of a Crew Exploration Vehicle (CEV)-class spacecraft with a total mass of 75,000 pounds, center of gravity (cg) height above the table of 284 inches, diameter of 18 feet, and capability of 1.25 gravity units peak acceleration in the vertical and 1.0 gravity units peak acceleration in the lateral directions. The MVF is a six-degree-of-freedom, servo-hydraulic, sinusoidal base-shake vibration system that has the advantage of being able to perform single-axis sine vibration testing of large structures in the vertical and two lateral axes without the need to reconfigure the test article for each axis. This paper discusses efforts to extend the MVF's capabilities so that it can also be used to determine fixed base modes of its test article without the need for an expensive test-correlated facility simulation
TDI noises transfer functions for LISA
The LISA mission is the future space-based gravitational wave (GW)observatory of the European Space Agency. It is formed by 3 spacecraftexchanging laser beams in order to form multiple real and virtualinterferometers. The data streams to be used in order to extract the largenumber and variety of GW sources are Time-Delay Interferometry (TDI) data. Oneimportant processing to produce these data is the TDI on-ground processingwhich recombines multiple interferometric on-board measurements to removecertain noise sources from the data such as laser frequency noise or spacecraftjitter. The LISA noise budget is therefore expressed at the TDI level in orderto account for the different TDI transfer functions applied for each noisesource and thus estimate their real weight on mission performance. In order toderive a usable form of these transfer functions, a model of the beams, themeasurements, and TDI have been developed, and several approximation have beenmade. A methodology for such a derivation has been established, as well asverification procedures. It results in a set of transfer functions, which arenow used by the LISA project, in particular in its performance model. Usingthese transfer functions, realistic noise curves for various instrumentalconfigurations are provided to data analysis algorithms and used for instrumentdesign.<br
Application of the Semi-Empirical Force-Limiting Approach for the CoNNeCT SCAN Testbed
The semi-empirical force-limiting vibration method was developed and implemented for payload testing to limit the structural impedance mismatch (high force) that occurs during shaker vibration testing. The method has since been extended for use in analytical models. The Space Communications and Navigation Testbed (SCAN Testbed), known at NASA as, the Communications, Navigation, and Networking re-Configurable Testbed (CoNNeCT), project utilized force-limiting testing and analysis following the semi-empirical approach. This paper presents the steps in performing a force-limiting analysis and then compares the results to test data recovered during the CoNNeCT force-limiting random vibration qualification test that took place at NASA Glenn Research Center (GRC) in the Structural Dynamics Laboratory (SDL) December 19, 2010 to January 7, 2011. A compilation of lessons learned and considerations for future force-limiting tests is also included
Hypergraph model of social tagging networks
The past few years have witnessed the great success of a new family of
paradigms, so-called folksonomy, which allows users to freely associate tags to
resources and efficiently manage them. In order to uncover the underlying
structures and user behaviors in folksonomy, in this paper, we propose an
evolutionary hypergrah model to explain the emerging statistical properties.
The present model introduces a novel mechanism that one can not only assign
tags to resources, but also retrieve resources via collaborative tags. We then
compare the model with a real-world dataset: \emph{Del.icio.us}. Indeed, the
present model shows considerable agreement with the empirical data in following
aspects: power-law hyperdegree distributions, negtive correlation between
clustering coefficients and hyperdegrees, and small average distances.
Furthermore, the model indicates that most tagging behaviors are motivated by
labeling tags to resources, and tags play a significant role in effectively
retrieving interesting resources and making acquaintance with congenial
friends. The proposed model may shed some light on the in-depth understanding
of the structure and function of folksonomy.Comment: 7 pages,7 figures, 32 reference
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