494 research outputs found
Unexpected sounds inhibit the movement of the eyes during reading and letter scanning
Novel sounds that unexpectedly deviate from a repetitive sound sequence are well known to cause distraction. Such unexpected sounds have also been shown to cause global motor inhibition, suggesting that they trigger a neurophysiological response aimed at stopping ongoing actions. Recently, evidence from eye movements has suggested that unexpected sounds also temporarily pause the movements of the eyes during reading, though it is unclear if this effect is due to inhibition of oculomotor planning or inhibition of language processes. Here, we sought to distinguish between these two possibilities by comparing a natural reading task to a letter scanning task that involves similar oculomotor demands to reading, but no higher level lexical processing. Participants either read sentences for comprehension or scanned letter strings of these sentences for the letter ‘o’ in three auditory conditions: silence, standard, and novel sounds. The results showed that novel sounds were equally distracting in both tasks, suggesting that they generally inhibit ongoing oculomotor processes independent of lexical processing. These results suggest that novel sounds may have a global suppressive effect on eye-movement control
Comparison of Simulator Wear Measured by Gravimetric vs Optical Surface Methods for Two Million Cycles
Understanding wear mechanisms are key for better implants
Critical to the success of the simulation
Small amount of metal wear can have catastrophic effects in the patient such as heavy metal poisoning or deterioration of the bone/implant interface leading to implant failure
Difficult to measure in heavy hard-on-hard implants (metal-on-metal or ceramic-on-ceramic)
May have only fractions of a milligram of wear on a 200 g component
At the limit of detection of even high-end balances when the component is 200 g and the change in weight is on the order of 0.000 1 grams
Here we compare the standard gravimetric wear estimate with
A non-contact 3D optical profiling method at each weighing stop
A coordinate measuring machine (CMM) at the beginning and end of the ru
Focus variation measurement and advanced analysis of volumetric loss at the femoral head taper interface of retrieved modular replacement hips in replica
This paper offers a technique for non-contact assessment of material volume loss at the femoral head taper interface of modular replacement hips with novel use of the focus variation principle. A novel 3D to areal data conversion technique also allows powerful areal data analysis techniques to be applied to point cloud (3D) measurements for volume loss optimisation. Accurate characterisation of retrieved femoral head tapers is important to assess their in vivo performance particularly with respect to the bio toxicity of wear and corrosion products. A cohort of 8 retrieved femoral heads showing a wide range of degradation (0.5mm^{3} < volume loss < 12mm^{3}) [1] was selected for the development of this technique. Using this common cohort of retrieved hips, the current technique was benchmarked against the well proven roundness measurement machine (RMM) method. This existing technique generates areal (2.5D) data and exploits a range of existing areal analysis techniques to optimise volume loss assessment. For benchmarking continuity and to exploit the same areal techniques, volume loss analysis for the current technique was carried out using the software written for the existing RMM method. The focus variation instrument's integrated language was used to write script to convert (un-wrap) the taper surface 3D data into areal format. The current method shows a mean absolute difference in volume loss of 14% (-12% signed) from that of the benchmark with a range of 1% to 27%. The spread of measured values is significantly higher for the current method than for the benchmark. However, it is noted that replication can offer the advantage of capturing the whole taper surface on some taper types where physical access is limited for a stylus based roundness method. The current technique is also compared to the existing Redluxâ„¢ technique in which replicated female tapers are measured using a confocal instrument. The current technique is shown to have comparable performance to the Redluxâ„¢ technique but offers a more sophisticated methodology for volume loss analysis. In addition the current technique offers new instrumentation and analysis tools to the field. Small uncontrolled casting variations are noted in the current technique, resulting in poorer performance with small volume loss samples where the influence of this effect is most pronounced. However, given the simplified assumptions of the volume loss calculation where results may be skewed by deposits, some uncertainty will be evident with any approach
The effects of mobile health on emergency care in low- and middle-income countries:A systematic review and narrative synthesis
101 Dothideomycetes genomes: A test case for predicting lifestyles and emergence of pathogens.
Dothideomycetes is the largest class of kingdom Fungi and comprises an incredible diversity of lifestyles, many of which have evolved multiple times. Plant pathogens represent a major ecological niche of the class Dothideomycetes and they are known to infect most major food crops and feedstocks for biomass and biofuel production. Studying the ecology and evolution of Dothideomycetes has significant implications for our fundamental understanding of fungal evolution, their adaptation to stress and host specificity, and practical implications with regard to the effects of climate change and on the food, feed, and livestock elements of the agro-economy. In this study, we present the first large-scale, whole-genome comparison of 101 Dothideomycetes introducing 55 newly sequenced species. The availability of whole-genome data produced a high-confidence phylogeny leading to reclassification of 25 organisms, provided a clearer picture of the relationships among the various families, and indicated that pathogenicity evolved multiple times within this class. We also identified gene family expansions and contractions across the Dothideomycetes phylogeny linked to ecological niches providing insights into genome evolution and adaptation across this group. Using machine-learning methods we classified fungi into lifestyle classes with >95 % accuracy and identified a small number of gene families that positively correlated with these distinctions. This can become a valuable tool for genome-based prediction of species lifestyle, especially for rarely seen and poorly studied species
Advancing Tests of Relativistic Gravity via Laser Ranging to Phobos
Phobos Laser Ranging (PLR) is a concept for a space mission designed to
advance tests of relativistic gravity in the solar system. PLR's primary
objective is to measure the curvature of space around the Sun, represented by
the Eddington parameter , with an accuracy of two parts in ,
thereby improving today's best result by two orders of magnitude. Other mission
goals include measurements of the time-rate-of-change of the gravitational
constant, and of the gravitational inverse square law at 1.5 AU
distances--with up to two orders-of-magnitude improvement for each. The science
parameters will be estimated using laser ranging measurements of the distance
between an Earth station and an active laser transponder on Phobos capable of
reaching mm-level range resolution. A transponder on Phobos sending 0.25 mJ, 10
ps pulses at 1 kHz, and receiving asynchronous 1 kHz pulses from earth via a 12
cm aperture will permit links that even at maximum range will exceed a photon
per second. A total measurement precision of 50 ps demands a few hundred
photons to average to 1 mm (3.3 ps) range precision. Existing satellite laser
ranging (SLR) facilities--with appropriate augmentation--may be able to
participate in PLR. Since Phobos' orbital period is about 8 hours, each
observatory is guaranteed visibility of the Phobos instrument every Earth day.
Given the current technology readiness level, PLR could be started in 2011 for
launch in 2016 for 3 years of science operations. We discuss the PLR's science
objectives, instrument, and mission design. We also present the details of
science simulations performed to support the mission's primary objectives.Comment: 25 pages, 10 figures, 9 table
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Volumetric reach comparison of possible end-effectors for the articulated transporter and manipulator system
The goal of this research was to investigate the performance of the Articulated Transporter and Manipulator System (ATMS) during various tasks relative to the choice of wrist/end-effector configuration. The approach taken was to generate computer graphics-aided three-dimensional interactive application (CATIA) system-based models of four wrist/end-effector combinations and consider the volumetric reach of each of these configurations based on the capacity of the ATMS. The results indicate that a simple, lightweight end-effector provides a greater volumetric reach. The greatest variation presented herein is {approximately}40% when comparing a 7-degree-of-freedom (DOF) dexterous arm with a simple 3-DOF arm; however, the benefit of increasing volumetric reach by only 40% by using a simple arm may be outweighed by the loss of dexterity. 10 refs., 5 figs., 3 tabs
Codes of Fair Competition: The National Recovery Act, 1933-1935, and the Women’s Dress Manufacturing Industry
Controversial issues prevalent in today’s ready-to-wear apparel industry include the right of workers to join unions, the proliferation of sweatshops and sweatshop conditions, and design piracy. The idea of forming codes of conduct to establish criteria of ethical business practices is not new to the apparel industry. Indeed, the women’s dress manufacturing industry discussed and debated codes of fair competition under the New Deal Policies of the National Recovery Act (NRA) of 1933 to 1935. Primary sources for this study included governmental hearings in the establishment of the NRA Dress Code, The New York Times, Women’s Wear Daily, and the Journal of the Patent Office Society. The history of the NRA codes implemented in the U.S. women’s ready-to-wear apparel industry provides an important case study highlighting the difficulties and complexities of creating and achieving industry-wide standard practices through self-regulation. The failure of the NRA demonstrates that even with the joint cooperation of industry, labor, and consumer groups and the backing of the force of law, codes of fair competition proved impossible to enforce
Synthesis and characterization of silicon nitride whiskers
Silicon nitride whiskers were synthesized by the carbothermal reduction of silica under nitrogen gas flow. The formation of silicon nitride whiskers occurs through a gas-phase reaction, 3SiO(g)+3CO(g)+2N 2 (g)=Si 3 N 4 ( β )+3CO 2 (g), and the VS mechanism. The generation of SiO gas was enhanced by the application of a halide bath. Various nitrogen flow rates resulted in different whisker yields and morphologies. A suitable gas composition range of N 2 , SiO and O 2 is necessary to make silicon nitride stable and grow in a whisker form. The oxygen partial pressure of the gas phase was measured by an oxygen sensor and the gas phase was analysed for CO/CO 2 by gas chromatography. Silicon nitride was first formed as a granule, typically a polycrystalline, and then grown as a single crystal whisker from the {1 0 0} plane of the granule along the 〈 210 〉 direction. The whiskers were identified as β ′-sialon with Z value ranging from 0.8 to 1.1, determined by lattice parameter measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44697/1/10853_2004_Article_BF01045372.pd
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