4,550 research outputs found
Wire mesh design
We present a computational approach for designing wire meshes, i.e., freeform surfaces composed of woven wires arranged in a regular grid. To facilitate shape exploration, we map material properties of wire meshes to the geometric model of Chebyshev nets. This abstraction is exploited to build an efficient optimization scheme. While the theory of Chebyshev nets suggests a highly constrained design space, we show that allowing controlled deviations from the underlying surface provides a rich shape space for design exploration. Our algorithm balances globally coupled material constraints with aesthetic and geometric design objectives that can be specified by the user in an interactive design session. In addition to sculptural art, wire meshes represent an innovative medium for industrial applications including composite materials and architectural façades. We demonstrate the effectiveness of our approach using a variety of digital and physical prototypes with a level of shape complexity unobtainable using previous methods
Addressing Gaps in Quality and Safety Education during Pre-Licensure Clinical Rotations
United States national reports have called for improvement in healthcare professions education to better address patient care outcomes. In response, an initiative titled âQuality and Safety Education for Nurses (QSEN)â has been adopted by nursing programs across the nation, which describes the six main competencies to be included in nursing curricula. As early adopters of the QSEN competencies, the University of San Francisco nursing faculty promptly threaded the material throughout the 4-year Bachelorâs of Science in Nursing (BSN) curriculum. Confident that the topics were well covered in the classroom, we then sought to learn how often our students practiced these skills during their assigned clinical rotations.
After completing an IRB-approved observational study of junior-level BSN students, we tallied the actual number of minutes spent in each competency area while assigned to the patient care unit. Using a time-on-task author developed QSEN-based tool, we found that our students spent little to no time engaged in quality improvement, evidence based practice, or informatics. This is a very important finding, as it indicates that our students may not be sufficiently developing these particular skills during assigned clinical hours.
Weaving the six QSEN competencies throughout the curriculum is a good start, but as we saw in our observational study, all of the competencies are not equally demonstrated in the clinical setting. Continuing to provide QSEN enriched didactic courses, adding targeted simulation experiences, and nourishing academic/practice partnerships may help bridge the gaps
Highly conductive molecular junctions based on direct binding of benzene to platinum electrodes
Highly conductive molecular junctions were formed by direct binding of
benzene molecules between two Pt electrodes. Measurements of conductance,
isotopic shift in inelastic spectroscopy and shot noise compared with
calculations provide indications for a stable molecular junction where the
benzene molecule is preserved intact and bonded to the Pt leads via carbon
atoms. The junction has a conductance comparable to that for metallic atomic
junctions (around 0.1-1 Go), where the conductance and the number of
transmission channels are controlled by the molecule's orientation at different
inter-electrode distances.Comment: 4 pages, 4 figure
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Amnesia and future thinking: Exploring the role of memory in the quantity and quality of episodic future thoughts.
OBJECTIVES: To examine the impact of memory accessibility on episodic future thinking. DESIGN: Single-case study of neurological patient HCM and an age-matched comparison group of neurologically Healthy Controls. METHODS: We administered a full battery of tests assessing general intelligence, memory, and executive functioning. To assess autobiographical memory, the Autobiographical Memory Interview (Kopelman, Wilson, & Baddeley, 1990. The Autobiographical Memory Interview. Bury St. Edmunds, UK: Thames Valley Test Company) was administered. The Past Episodic and Future Episodic sections of Dalla Barba's Confabulation Battery (Dalla Barba, 1993, Cogn. Neuropsychol., 1, 1) and a specifically tailored Mental Time Travel Questionnaire were administered to assess future thinking in HCM and age-matched controls. RESULTS: HCM presented with a deficit in forming new memories (anterograde amnesia) and recalling events from before the onset of neurological impairment (retrograde amnesia). HCM's autobiographical memory impairments are characterized by a paucity of memories from Recent Life. In comparison with controls, two features of his future thoughts are apparent: Reduced episodic future thinking and outdated content of his episodic future thoughts. CONCLUSIONS: This article suggests neuropsychologists should look beyond popular conceptualizations of the past-future relation in amnesia via focussing on reduced future thinking. Investigating both the quantity and quality of future thoughts produced by amnesic patients may lead to developments in understanding the complex nature of future thinking disorders resulting from memory impairments. PRACTITIONER POINTS: We highlight the clinical importance of examining the content of future thoughts in amnesic patients, rather than only its quantitative reduction. We propose an explanation of how quantitative and qualitative aspects of future thinking could be affected by amnesia. This could provide a useful approach to understand clinical cases of impaired prospection. LIMITATIONS: Systematic group investigations are required to fully examine our hypothesis. Although the current study utilized typical future thinking measures, these may be limited and we highlight the need to develop clinically relevant measures of prospection
Probing two topological surface bands of Sb2Te3 by spin-polarized photoemission spectroscopy
Using high resolution spin- and angle-resolved photoemission spectroscopy, we
map the electronic structure and spin texture of the surface states of the
topological insulator Sb2Te3. In combination with density functional
calculations (DFT), we directly show that Sb2Te3 exhibits a partially occupied,
single spin-Dirac cone around the Fermi energy, which is topologically
protected. DFT obtains a spin polarization of the occupied Dirac cone states of
80-90%, which is in reasonable agreement with the experimental data after
careful background subtraction. Furthermore, we observe a strongly spin-orbit
split surface band at lower energy. This state is found at 0.8eV below the
Fermi level at the gamma-point, disperses upwards, and disappears at about
0.4eV below the Fermi level into two different bulk bands. Along the gamma-K
direction, the band is located within a spin-orbit gap. According to an
argument given by Pendry and Gurman in 1975, such a gap must contain a surface
state, if it is located away from the high symmetry points of the Brillouin
zone. Thus, the novel spin-split state is protected by symmetry, too.Comment: 8 pages, 10 figure
Bio-ORACLE: a global environmental dataset for marine species distribution modeling
The oceans harbor a great diversity of organisms whose distribution and ecological preferences are often poorly understood. Species distribution modeling (SDM) could improve our knowledge and inform marine ecosystem management and conservation. Although marine environmental data are available from various sources, there are currently no user-friendly, high-resolution global datasets designed for SDM applications. This study aims to ?ll this gap by assembling a comprehensive, uniform, high-resolution and readily usable package of global environmental rasters. We compiled global coverage data, e.g. satellite-based and in situ measured data, representing various aspects of the marine environment relevant for species distributions. Rasters were assembled at a resolution of 5 arcmin (c. 9.2 km) and a uniform landmask was applied. The utility of the dataset was evaluated by maximum entropy SDM of the invasive seaweed Codium fragile ssp. fragile. We present Bio-ORACLE (ocean rasters for analysis of climate and environment), a global dataset consisting of 23 geophysical, biotic and climate rasters. This user-friendly data package for marine species distribution modeling is available for download at http://www.bio-oracle.ugent.be. The high predictive power of the distribution model of C. fragile ssp. fragile clearly illustrates the potential of the data package for SDM of shallow-water marine organisms. The availability of this global environmental data package has the potential to stimulate marine SDM. The high predictive success of the presence-only model of a notorious invasive seaweed shows that the information contained in Bio-ORACLE can be informative about marine distributions and permits building highly accurate species distribution models
Effect of Residual Sugar in High Sugar Grass Silages on Aerobic Stability
New varieties of Lolium perenne, bred for high sugar content, can contain up to 30% of water soluble carbohydrates (WSC). Only a fraction of such high contents are metabolised during a normal fermentation and the high residual sugar content (RSC) of these silages can improve the efficiency of use of nitrogen by ruminants. However, these RSC at opening for feed-out could be preferentially metabolised relative to fermentation products by all aerobically growing fungi and bacteria present on the forage. A high RSC thus can increase the risk of aerobic deterioration over that of extensively fermented silages, containing predominantly organic acids, which are initially utilised by certain yeasts. The objective of this study was to assess the relationship between RSC and aerobic stability of silages prepared with either optimal ensiling conditions or with a defined air challenge treatment to make them prone to aerobic deterioration. The latter is a useful method to test the efficacy of aerobic stability improving silage additives, requiring unstable controls (Pahlow et al., 1999)
Towards 1H-MRSI of the human brain at 7T with slice-selective adiabatic refocusing pulses
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70576.pdf (publisher's version ) (Closed access)OBJECTIVE: To explore the possibilities of proton spectroscopic imaging (1H-MRSI) of the human brain at 7 Tesla with adiabatic refocusing pulses. MATERIALS AND METHODS: A combination of conventional slice selective excitation and two pairs of slice selective adiabatic refocusing pulses (semi-LASER) results in the formation of an echo from a localized volume. Depending on the used radio frequency (rf) coil efficiency and available rf power, the duration of the adiabatic full passage pulses (AFPs) is adapted to enable echo times down to 50 ms (head coil) or 30 ms (local surface coil). RESULTS: An AFP duration of 5 ms with a corresponding bandwidth of 5.1 kHz resulted in a chemical shift displacement error of 23% over 3.8 ppm at 7T. Using a local surface coil and an echo time down to 30 ms, we detected not only the three main metabolites (NAA, Cr and Cho), but also coupled signals from myo-inositol and glutamate/glutamine in spectra from 0.14 cc voxels with linewidths down to 10 Hz in 10 min measurement time. CONCLUSIONS: The semi-LASER pulse sequence enables 1H-MRSI of the human brain at 7T for larger parts of the brain as well as small localized areas with both a high spectral and spatial resolution
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