310 research outputs found
Development of a Freight Demand Model with an Application to California
ABSTRACTThis paper discusses the disaggregation of the Federal Highway Administration's Freight Analysis Framework (FAF) database (version 3.0) on freight origin-destination data and the development of linear regression equations to describe the relationships between commodity-based freight trip productions/attractions to specific economic variables. Instead of generating a production/attraction equation for each commodity, commodities are grouped in certain ways to simplify model development and application. We consider three grouping methods and two model selection criteria (with and without intercepts), which are compared in terms of goodness of fit with two data sets (FAF versions 2.0 and 3.0). Furthermore, the freight generation models are validated using county-level economic data in California and applied to predict year 2015 commodity outputs. The results of this study can help city, county, metropolitan and state level planning agencies develop their own customized freight demand generation models without performing costly large-scale surveys
The FANTASTIC FOUR proteins influence shoot meristem size in Arabidopsis thaliana
<p>Abstract</p> <p>Background</p> <p>Throughout their lives plants produce new organs from groups of pluripotent cells called meristems, located at the tips of the shoot and the root. The size of the shoot meristem is tightly controlled by a feedback loop, which involves the homeodomain transcription factor WUSCHEL (WUS) and the CLAVATA (CLV) proteins. This regulatory circuit is further fine-tuned by morphogenic signals such as hormones and sugars.</p> <p>Results</p> <p>Here we show that a family of four plant-specific proteins, encoded by the <it>FANTASTIC FOUR </it>(<it>FAF</it>) genes, has the potential to regulate shoot meristem size in <it>Arabidopsis thaliana</it>. <it>FAF2 </it>and <it>FAF4 </it>are expressed in the centre of the shoot meristem, overlapping with the site of <it>WUS </it>expression. Consistent with a regulatory interaction between the <it>FAF </it>gene family and <it>WUS</it>, our experiments indicate that the FAFs can repress <it>WUS</it>, which ultimately leads to an arrest of meristem activity in <it>FAF </it>overexpressing lines. The finding that meristematic expression of <it>FAF2 </it>and <it>FAF4 </it>is under negative control by CLV3 further supports the hypothesis that the FAFs are modulators of the genetic circuit that regulates the meristem.</p> <p>Conclusion</p> <p>This study reports the initial characterization of the <it>Arabidopsis thaliana FAF </it>gene family. Our data indicate that the <it>FAF </it>genes form a plant specific gene family, the members of which have the potential to regulate the size of the shoot meristem by modulating the CLV3-WUS feedback loop.</p
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Retrieving information from heterogeneous freight data sources to answer natural language queries
textThe ability to retrieve accurate information from databases without an extensive knowledge of the contents and organization of each database is extremely beneficial to the dissemination and utilization of freight data. The challenges, however, are: 1) correctly identifying only the relevant information and keywords from questions when dealing with multiple sentence structures, and 2) automatically retrieving, preprocessing, and understanding multiple data sources to determine the best answer to user’s query. Current named entity recognition systems have the ability to identify entities but require an annotated corpus for training which in the field of transportation planning does not currently exist. A hybrid approach which combines multiple models to classify specific named entities was therefore proposed as an alternative. The retrieval and classification of freight related keywords facilitated the process of finding which databases are capable of answering a question. Values in data dictionaries can be queried by mapping keywords to data element fields in various freight databases using ontologies. A number of challenges still arise as a result of different entities sharing the same names, the same entity having multiple names, and differences in classification systems. Dealing with ambiguities is required to accurately determine which database provides the best answer from the list of applicable sources. This dissertation 1) develops an approach to identify and classifying keywords from freight related natural language queries, 2) develops a standardized knowledge representation of freight data sources using an ontology that both computer systems and domain experts can utilize to identify relevant freight data sources, and 3) provides recommendations for addressing ambiguities in freight related named entities. Finally, the use of knowledge base expert systems to intelligently sift through data sources to determine which ones provide the best answer to a user’s question is proposed.Civil, Architectural, and Environmental Engineerin
Prognostication in Stargardt disease using Fundus Autofluorescence: Improving Patient Care
PURPOSE: To explore fundus autofluorescence (FAF) imaging as an alternative to electroretinogram (ERG), as a non-invasive, quick, and readily interpretable method to predict disease progression in Stargardt disease (STGD). DESIGN: Retrospective case series of patients who attended Moorfields Eye Hospital (London, UK). SUBJECTS: Patients with STGD who met the following criteria were included: (i) biallelic disease-causing variants in ABCA4, (ii) ERG testing performed inhouse with an unequivocal ERG group classification, and (iii) ultra-widefield (UWF) FAF imaging performed up to 2 years before or after the ERG. METHODS: Patients were divided into three ERG groups based on retinal function and three FAF groups according to the extent of the hypoautofluorescence and their retinal background appearance. FAF imaging of 30 and 55° were also subsequently reviewed. MAIN OUTCOME MEASURES: ERG/FAF concordance and its association with baseline visual acuity and genetics. RESULTS: 234 patients were included in the cohort. 170 patients (73%) had the same ERG and FAF group, 33 (14%) had a milder FAF than ERG group, and 31 (13%) had a more severe FAF than ERG group. Children under the age of 10 (n=23) had the lowest ERG/FAF concordance, 57% (9 out of the 10 with discordant ERG/FAF had milder FAF than ERG), and adults with adult onset had the highest (80%). Missense genotypes were more commonly seen in the mildest phenotypes. In 97% and 98% of the cases, respectively, 30° and 55° FAF imaging matched with the group defined by UWF FAF. CONCLUSIONS: We demonstrate that FAF imaging is an effective modality to determine the extent of retinal involvement and thereby inform prognostication, by comparing FAF to the current gold standard of ERG testing to determine retinal involvement and thereby prognosis. In 80% of patients in our large molecularly proven cohort we were able to predict if the disease was confined to the macula or also affected the peripheral retina. Children assessed at a young age, with at least one null variant, early disease onset, and/or poor initial VA may have wider retinal involvement than predicted by FAF alone and/or progress to a more severe FAF phenotype over time
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Integrating Public and Private Data Sources for Freight Transportation Planning
The Moving Ahead for Progress in the 21st Century Act (MAP-21) stipulates that state transportation agencies
expand their interest in freight initiatives and modeling to support planning efforts, particularly the evaluation of
current and future freight transportation capacity necessary to ensure freight mobility. However, the
understanding of freight demand and the evaluation of current and future freight transportation capacity are not
only determined by robust models, but are critically contingent on the availability of accurate data. Effective
partnerships are clearly needed between the public and private sectors to ensure adequate freight planning and
funding of transportation infrastructure at the state and local levels. However, establishing partnerships with
firms who are both busy and suspicious of data-sharing, remains a challenge. This study was commissioned by
the Texas Department of Transportation (TxDOT) to explore the feasibility of TxDOT entering into a data-sharing partnership with representatives of the private sector to obtain sample data for use in formulating a
strategy for integrating public and private sector data sources. This report summarizes the findings, lessons
learned, and recommendations formed from the outreach effort, and provides a prototype freight data architecture
that will facilitate the storage, exchange, and integration of freight data through a data-sharing partnership.Texas Department of Transportation
Research and Technology Implementation Office
P.O. Box 5080
Austin, TX 78763-5080Civil, Architectural, and Environmental Engineerin
Exploring the Potential of Supercritical Fluid Extraction of Matricaria chamomilla White Ray Florets as a Source of Bioactive (Cosmetic) Ingredients
Funding Information: This research was funded by the European Regional Development Fund project “Biorefinery approach for the development of bioactive cosmetic ingredients from byproducts of medicinal plant processing and plant cell cultivation” (No. 1.1.1.1/19/A/075). Publisher Copyright: © 2023 by the authors.Aromatic and medicinal plants are a great source of useful bioactive compounds for use in cosmetics, drugs, and dietary supplements. This study investigated the potential of using supercritical fluid extracts obtained from Matricaria chamomilla white ray florets, a kind of industrial herbal byproduct, as a source of bioactive cosmetic ingredients. Response surface methodology to optimize the supercritical fluid extraction process by analyzing the impact of pressure and temperature on yield and the main bioactive compound groups were used. High-throughput 96-well plate spectrophotometric methods were used to analyze the extracts for total phenols, flavonoids, tannins, and sugars, as well as their antioxidant capacity. Gas chromatography and liquid chromatography-mass spectrometry was used to determine the phytochemical composition of the extracts. The extracts were also analyzed for antimicrobial activity, cytotoxicity, phototoxicity, and melanin content. Statistical analysis was performed to establish correlations between the extracts and develop models to predict the targeted phytochemical recovery and chemical and biological activities. The results show that the extracts contained a diverse range of phytochemical classes and had cytotoxic, proliferation-reducing, and antimicrobial activities, making them potentially useful in cosmetic formulations. This study provides valuable insights for further research on the uses and mechanisms of action of these extracts.publishersversionPeer reviewe
A measurement of the cosmic microwave background radiation (CMBR) anisotropy at the half degree angular scale
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1996.Includes bibliographical references (p. 127-130).by Casey Ann Inman.Ph.D
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