1,837 research outputs found

    Stimulus-specific mechanisms of visual short-term memory

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    The retention of spatial information in visual short-term memory was assessed by measuring spatial frequency discrimination thresholds with a two-interval forced-choice task varying the time interval between the two gratings to be compared. The memory of spatial frequency information was perfect across 10-sec interstimulus intervals. Presentation of a “memory masker” grating during the interstimulus interval may interfere with short-term memory. This interference depends on the relative spatial frequency of the test and masker gratings, with maximum interference at spatial frequency differences of 1–1.5 octaves and beyond. This range of interference with short-term memory is comparable to the bandwidth of sensory masking or adaptation. A change of the relative orientation of test and masker gratings does not produce interference with spatial frequency discrimination thresholds. These results suggest stimulus-specific interactions at higher-level representations of visual form

    Snowsports injuries among orthopaedic surgeons

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    Atomic structure of Cu adlayers on Au(100) and Au(111) electrodes observed by in situ scanning tunneling microscopy

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    The atomic structure of ordered Cu adsorbate layers on Au(111) and Au(100) electrode surfaces and of the clean substrates was resolved in scanning tunneling microscopy images taken in situ. For submonolayer coverages deposited from sulfuric acid solutions under potential control, various ordered structures were observed. The quasihexagonal arrangement of Cu atoms in these structures reflects increasingly repulsive interactions between closely spaced Cu adatoms. These structures differ from the pseudomorphic Cu adlayer formed under vacuum conditions, which demonstrates the structure-determining role of the coadsorbed anions

    Current thinking and new paradigm for COPD

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    AbstractDuring the 2015 European Respiratory Society Congress, a symposium was held on ‘Current thinking and new paradigm for COPD’. Through a combination of plenary lectures and interactive panel discussions, experts discussed the recent evidence for chronic obstructive pulmonary disease (COPD) treatment and how this evidence can be applied in clinical practice

    The influence of spatial pattern on visual short-term memory for contrast

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    Several psychophysical studies of visual short-term memory (VSTM) have shown high-fidelity storage capacity for many properties of visual stimuli. On judgments of the spatial frequency of gratings, for example, discrimination performance does not decrease significantly, even for memory intervals of up to 30 s. For other properties, such as stimulus orientation and contrast, however, such “perfect storage” behavior is not found, although the reasons for this difference remain unresolved. Here, we report two experiments in which we investigated the nature of the representation of stimulus contrast in VSTM using spatially complex, two-dimensional random-noise stimuli. We addressed whether information about contrast per se is retained during the memory interval by using a test stimulus with the same spatial structure but either the same or the opposite local contrast polarity, with respect to the comparison (i.e., remembered) stimulus. We found that discrimination thresholds got steadily worse with increasing duration of the memory interval. Furthermore, performance was better when the test and comparison stimuli had the same local contrast polarity than when they were contrast-reversed. Finally, when a noise mask was introduced during the memory interval, its disruptive effect was maximal when the spatial configuration of its constituent elements was uncorrelated with those of the comparison and test stimuli. These results suggest that VSTMfor contrast is closely tied to the spatial configuration of stimuli and is not transformed into a more abstract representation

    Treatment of Advanced Emphysema with Emphysematous Lung Sealant (AeriSeal (R))

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    Background: This report summarizes initial tests of an emphysematous lung synthetic polymer sealant (ELS) designed to reduce lung volume in patients with advanced emphysema. Objectives: The primary study objective was to define a therapeutic strategy to optimize treatment safety and effectiveness. Methods: ELS therapy was administered bronchoscopically to 25 patients with heterogeneous emphysema in an open-label, noncontrolled study at 6 centers in Germany. Treatment was performed initially at 2-4 subsegments. After 12 weeks, patients were eligible for repeat therapy to a total of 6 sites. Safety and efficacy were assessed after 6 months. Responses were evaluated in terms of changes from baseline in lung physiology, functional capacity, and health-related quality of life. Follow-up is available for 21 of 25 patients. Results: Treatment was well tolerated. There were no treatment-related deaths (i.e. within 90 days of treatment), and an acceptable short-and long-term safety profile. Physiological and clinical benefits were observed at 24 weeks. Efficacy responses were better among Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage III patients {[}n = 14; change in residual volume/total lung capacity (Delta RV/TLC) = -7.4 +/- 10.3%; Delta forced expiratory volume in 1 s (Delta FEV(1)) = +15.9 +/- 22.6%; change in forced vital capacity (Delta FVC) = +24.1 +/- 22.7%; change in carbon monoxide lung diffusion capacity (Delta DLCO) = +19.3 +/- 34.8%; change in 6-min walk test (Delta 6MWD) = +28.7 +/- 59.6 m; change in Medical Research Council Dyspnea (Delta MRCD) score = -1.0 +/- 1.04 units; change in St. George's Respiratory Questionnaire (Delta SGRQ) score = -9.9 +/- 15.3 units] than for GOLD stage IV patients (n = 7; Delta RV/TLC = -0.5 +/- 6.4%; Delta FEV 1 = +2.3 +/- 12.3%; Delta FVC = +2.6 +/- 21.1%; Delta DLCO = -2.8 +/- 17.2%; Delta 6MWD = +28.3 +/- 58.4 m; Delta MRCD = 0.3 +/- 0.81 units; Delta SGRQ = -6.7 +/- 7.0 units). Conclusions: ELS therapy shows promise for treating patients with advanced heterogeneous emphysema. Additional studies to assess responses in a larger cohort with a longer follow-up are warranted. Copyright (C) 2011 S. Karger AG, Base

    Evidences on overweight of regular blood donors in a center of Southern Italy

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    Objective: Smoking, unhealthy diet and obesity, sedentary behavior and inability to maintain adequate exercise have significant consequences for several chronic disorders. Blood centers can play a public health role in obesity surveillance and interventions. The purpose study was to evaluate the health status of the blood donors by monitoring the nutritional habits and lifestyle. Methods: A descriptive cross-sectional face-to-face questionnaire was developed. It included a 41 item dietary assessment, reporting semi-quantitative food frequency, dietary behavior and questions on self-rated health status. Donors were regular repeat blood donors, eligible to donate. Results: Of the 2468 blood donors enrolled between July 2017 and January 2018, 1390 were repeat donors. Only 205 agreed to respond to the questionnaire. Data showed that donors followed mainly a Mediterranean diet and had more awareness to lifestyle, women more than men, in comparison with general population. The prevalence of overweight was found 50.7% in men and 16.9% in women. Conclusions: Overweight and obesity are common among regular blood donors and it is more frequent in men than women. The female blood donors seem to be characterized by better knowledge on the relationship between lifestyle and health, and by a better “putting into practice” of the information possessed

    Long-term follow-up of disability pensioners having musculoskeletal disorders

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    <p>Abstract</p> <p>Background</p> <p>Previously we have conducted a randomised controlled trial (RCT) to evaluate the effect of a brief cognitive behavioural program with a vocational approach aiming to return disability pensioners with back pain to work, as compared to no intervention. One year after the intervention, 10 participants (22%) who received the program and 5 (11%) in the control group reported to have entered a return to work process. The aims of this study were to evaluate long-term effects of the intervention, and compare this effect to 2 reference populations not participating in the original trial.</p> <p>Methods</p> <p>Three groups of disability pensioners were investigated: 1) Disability pensioners having back pain (n = 89) previously participating in the RCT (randomized to either a brief cognitive behavioural intervention or to a control group), 2) 342 disability pensioners having back pain, but refusing to participate in the study and 3) 449 disability pensioners having other musculoskeletal disorders than back pain. Primary outcome was return to work, defined as a reduction in payment of disability pension.</p> <p>Results</p> <p>Only 2 of 89 (2.3%) participants from the RCT had reduced disability pension at 3-years follow-up, both from the control group. None of the participants that had been in a process of returning to work after 1 year had actually gained employment at 3-years follow-up. In the 2 groups not participating in the previous RCT, only 4 (1.2%) and 8 (1.6%) had returned to work after 3 years respectively.</p> <p>Conclusion</p> <p>The number of pensioners who returned to work was negligible in all groups regardless of having participated in a cognitive behavioural intervention or not.</p

    Modeling the effects of concentration of solid nanoparticles in liquid feedstock injection on high-velocity suspension flame spray process

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    This paper presents the effects of the concentration of solid nanoparticles in the liquid feedstock injection on the high-velocity suspension flame spray (HVSFS) process. Four different concentrations of solid nanoparticles in suspension droplets with various droplet diameters are used to study gas dynamics, vaporization rate, and secondary breakup. Two types of injections, viz. surface and group, are used. The group-type injection increases the efficiency of droplet disintegration and the evaporation process and reduces the gas cooling. The initiation of the fragmentation process is difficult for small droplets carrying a high concentration of nanoparticles. Also, smaller droplets undergo rapid vaporization, leaving clogs of nanoparticles in the middle of the barrel. For larger droplets, severe fragmentation occurs inside the combustion chamber. For a higher concentration of nanoparticles, droplets exit the gun without complete evaporation. The results suggest that, in coating applications involving a higher concentration of nanoparticles, smaller droplet sizes are preferred
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