640 research outputs found
Eye position modulates retinotopic responses in early visual areas: a bias for the straight-ahead direction
Even though the eyes constantly change position, the location of a stimulus can be accurately represented by a population of neurons with retinotopic receptive fields modulated by eye position gain fields. Recent electrophysiological studies, however, indicate that eye position gain fields may serve an additional function since they have a non-uniform spatial distribution that increases the neural response to stimuli in the straight-ahead direction. We used functional magnetic resonance imaging and a wide-field stimulus display to determine whether gaze modulations in early human visual cortex enhance the blood-oxygenation-level dependent (BOLD) response to stimuli that are straight-ahead. Subjects viewed rotating polar angle wedge stimuli centered straight-ahead or vertically displaced by ±20° eccentricity. Gaze position did not affect the topography of polar phase-angle maps, confirming that coding was retinotopic, but did affect the amplitude of the BOLD response, consistent with a gain field. In agreement with recent electrophysiological studies, BOLD responses in V1 and V2 to a wedge stimulus at a fixed retinal locus decreased when the wedge location in head-centered coordinates was farther from the straight-ahead direction. We conclude that stimulus-evoked BOLD signals are modulated by a systematic, non-uniform distribution of eye-position gain fields
Trust and Risk Relationship Analysis on a Workflow Basis: A Use Case
Trust and risk are often seen in proportion to each other; as such, high trust may induce low risk and vice versa. However, recent research argues that trust and risk relationship is implicit rather than proportional. Considering that trust and risk are implicit, this paper proposes for the first time a novel approach to view trust and risk on a basis of a W3C PROV provenance data model applied in a healthcare domain. We argue that high trust in healthcare domain can be placed in data despite of its high risk, and low trust data can have low risk depending on data quality attributes and its provenance. This is demonstrated by our trust and risk models applied to the BII case study data. The proposed theoretical approach first calculates risk values at each workflow step considering PROV concepts and second, aggregates the final risk score for the whole provenance chain. Different from risk model, trust of a workflow is derived by applying DS/AHP method. The results prove our assumption that trust and risk relationship is implicit
New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign â Seafloor Photographs
The New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign â Seafloor Photographsâ was developed by the University of New Hampshire (UNH) Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC). The field campaign was conducted to provide ground truth for surficial geology maps for the continental shelf off New Hampshire (NH) and focused on the inner shelf between the coast and the Isles of Shoals. Station locations were chosen where high-resolution bathymetry was available, including multibeam echosounder (MBES) surveys conducted by the UNH CCOM/JHC Hydrographic Field Course (Ocean Engineering 972), MBES surveys by the NOAA National Ocean Service (NOS), and a topo-bathy lidar (Shoals) survey by the United States Geological Survey (USGS) (see Ward et al., 2021c for details). In total, seafloor videography was collected at 151 stations and 855 photographs were extracted from the video. In addition, 150 sediment samples were collected from 85 of the stations and analyzed for grain size. The bottom sediment grain size data is available at the University of New Hampshire Scholars Repository (see Ward et al., 2021 https://dx.doi.org/10.34051/d/2021.2
New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign â Seafloor and Sample Photographs and Sediment Data
The New Hampshire Continental Shelf Geophysical Database: 2016-2017 Field Campaign - Seafloor and Sample Photographs and Sediment Data contains photographs of the seafloor from sampling locations, photographs of the sediment samples, and grain size data from a major field campaign conducted in 2016- 2017 and from the UNH Ocean Engineering 972 Hydrographic Field Course classes in 2012, 2014, and 2018. In total, sixteen one-day cruises provided 150 samples for grain size analysis. The database provides complete descriptions for each sample including identification, station and sample characteristics, sediment classifications, grain size statistics, and grain size distribution. Presented here are tables with the station locations and types of data available followed by single sample summaries for each sample collected and analyzed. Included in each summary are location information, seafloor photographs, photographs of the sample (in field and laboratory) where available, collection information, sediment classifications, grain size statistics, and grain size distribution. Samples were analyzed with standard sieve and pipette analyses after Folk (1980). The sediment grain size classifications include: CMECS (Coastal and Marine Ecological Classification Standard; FGDC, 2012); Gradistat (Blot and Pye, 2001); and Wentworth (Wentworth, 1922; described in Folk, 1954, 1980). Statistics are based on the phi scale and include the graphic mean, sorting, skewness, and kurtosis (Folk, 1980)
New Hampshire and Vicinity Continental Shelf: Sand and Gravel Resources
The continental shelf off New Hampshire (NH) has extensive marine-modified glacial deposits and associated shoals. These features are potential targets for sand and gravel resources for beach nourishment and other efforts to build coastal resiliency. The distribution of sand and gravel deposits was evaluated based on the synthesis of relatively recent high-resolution bathymetry, new surficial sediment and geoform maps, and an extensive data archive that includes over ~1280 km of seismic profiles, ~750 grain size analyses, and 23 vibracores. This work heavily utilizes the results of previous research on mineral resources on the NH shelf by Birch (1984) and others. Unfortunately, much of the archived data was collected before the Global Navigation Satellite System (GNSS) was used routinely for navigation on research vessels. Consequently, much of the critical data from the archives has a large uncertainty associated with the positioning. Furthermore, the seismics are of variable quality. Nevertheless, the data archives coupled with recent high-resolution bathymetry and surficial sediment mapping, provided the basis to develop an initial or first order evaluation of the sand and gravel resources and identify areas where follow-up field campaigns are warranted. This report focuses on four sites where sand and fine gravel deposits may be suitable for extraction for beach nourishment. The most promising sites are referred to as the Northern Sand Body (NSB) and the Southern Sand Deposits (SSD). Estimates of the volume of sand and fine gravel potentially available in the NSB and the SSD are on the order of 17.3 million m3 and 16.4 million m3, respectively. However, these values represent the total volume defined by subbottom seismics and include very fine sand and mud. Therefore, the volume of material that may be available for beach nourishment is likely considerably less. Both of these areas, as well as other potential sites identified, need high-resolution seismic surveys and vibracores to fully evaluate the potential sand and fine gravel resources
Research In Outdoor Education: Group Development And Group Dynamics
This article contains the text of a keynote presentation at the Inaugural Symposium for Research in Outdoor Education at Bradford Woods, January 1992,. The presentation focused on the development of positive group dynamics
Consumers' Shopping Patterns and Expenditures on Ethnic Produce: A Case Study from the Eastern Coastal U.S.A.
This study was undertaken to examine the possible niche markets which East Coast farmers might be able to use to regain their advantage. Their future economic success could hinge on shifting the focus from traditional fruits and vegetables to high-value specialty ethnic produce for which there might be a growing demand. The study results indicate that there is a strong market demand and interest for ethnic produce in the East Coast. Local producers can benefit by concentrating their efforts in producing ethnic vegetables and fresh produce and making these newer products available in the local and regional markets.Food Consumption/Nutrition/Food Safety,
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