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Studia Slavica
Authors:
János L. Nagy
,
Mihály Káprály
,
Mária Tétényi
,
István Fried
, and
Zsuzsanna Kalafatics

Nyelv, stílus, irodalom. Köszönto könyv Péter Mihály 70. születésnapjára. Budapest 1998, 646 p. (????, ?. ?.); - ?????? ?., ??????? ????? ??? ?????? ??????????? ????????? ?. ????????? ????????? ????????????? ???????? ?????? ???????????.(Studia Ukrainica et Rusinica Nyíregyháziensia 12). ?????????? 2002, 238 p. ( ???????, ?.); - ?. ?. ??????? ? ?. ?. ???????, ????????? ? ?. ?. ?????????. The Tolstoys' Correspo ndence with N. N. Strakhov. (?? ??????? ???????????????? ????? ?. ?. ????????). A. A. Donskov (Ed.). Compiled by L. D. Gromova & T. G. Nikiforova. (Tolstoy Series 3). Slavic Research Group at the University of Ottawa and State L. N. Tolstoy Museum, Moscow, 2000, 308 p. (??????, ?.); - Marija Mitrovic, Geschichte der slowenischen Literatur. Von den Anfängen bis zur Gegenwart. Klagenfurt-Ljubljana-Wien 2001. 617 p. (Fried, I.); - ??????? ??????? ??????????? ??????????? ???????? I. ?????? 2001, 213 p. (?????????, ?.)

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Learning & Perception
Authors:
Orsolya Szalárdy
,
Alexandra Bendixen
,
Dénes Tóth
,
Susan L. Denham
, and
István Winkler

In our surrounding acoustic world sounds are produced by different sources and interfere with each other before arriving to the ears. A key function of the auditory system is to provide consistent and robust descriptions of the coherent sound groupings and sequences (auditory objects), which likely correspond to the various sound sources in the environment. This function has been termed auditory stream segregation. In the current study we tested the effects of separation in the frequency of amplitude modulation on the segregation of concurrent sound sequences in the auditory stream–segregation paradigm (van Noorden 1975). The aim of the study was to assess 1) whether differential amplitude modulation would help in separating concurrent sound sequences and 2) whether this cue would interact with previously studied static cues (carrier frequency and location difference) in segregating concurrent streams of sound. We found that amplitude modulation difference is utilized as a primary cue for the stream segregation and it interacts with other primary cues such as frequency and location difference.

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The auditory two-tone streaming paradigm has been used extensively to study the mechanisms that underlie the decomposition of the auditory input into coherent sound sequences. Using longer tone sequences than usual in the literature, we show that listeners hold their first percept of the sound sequence for a relatively long period, after which perception switches between two or more alternative sound organizations, each held on average for a much shorter duration. The first percept also differs from subsequent ones in that stimulus parameters influence its quality and duration to a far greater degree than the subsequent ones. We propose an account of auditory streaming in terms of rivalry between competing temporal associations based on two sets of processes. The formation of associations (discovery of alternative interpretations) mainly affects the first percept by determining which sound group is discovered first and how long it takes for alternative groups to be established. In contrast, subsequent percepts arise from stochastic switching between the alternatives, the dynamics of which are determined by competitive interactions between the set of coexisting interpretations.

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Learning & Perception
Authors:
Orsolya Szalárdy
,
Alexandra Bendixen
,
Dénes Tóth
,
Susan L. Denham
, and
István Winkler

In our surrounding acoustic world sounds are produced by different sources and interfere with each other before arriving to the ears. A key function of the auditory system is to provide consistent and robust descriptions of the coherent sound groupings and sequences (auditory objects), which likely correspond to the various sound sources in the environment. This function has been termed auditory stream segregation. In the current study we tested the effects of separation in the frequency of amplitude modulation on the segregation of concurrent sound sequences in the auditory stream–segregation paradigm (van Noorden 1975). The aim of the study was to assess 1) whether differential amplitude modulation would help in separating concurrent sound sequences and 2) whether this cue would interact with previously studied static cues (carrier frequency and location difference) in segregating concurrent streams of sound. We found that amplitude modulation difference is utilized as a primary cue for the stream segregation and it interacts with other primary cues such as frequency and location difference.

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The auditory two-tone streaming paradigm has been used extensively to study the mechanisms that underlie the decomposition of the auditory input into coherent sound sequences. Using longer tone sequences than usual in the literature, we show that listeners hold their first percept of the sound sequence for a relatively long period, after which perception switches between two or more alternative sound organizations, each held on average for a much shorter duration. The first percept also differs from subsequent ones in that stimulus parameters influence its quality and duration to a far greater degree than the subsequent ones. We propose an account of auditory streaming in terms of rivalry between competing temporal associations based on two sets of processes. The formation of associations (discovery of alternative interpretations) mainly affects the first percept by determining which sound group is discovered first and how long it takes for alternative groups to be established. In contrast, subsequent percepts arise from stochastic switching between the alternatives, the dynamics of which are determined by competitive interactions between the set of coexisting interpretations.

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Abstract

Purpose

The aim of this study was to assess longitudinal changes in retinal vessel density in diabetic patients using optical coherence tomography angiography (OCTA) to identify the most sensitive parameter for detecting retinopathy progression.

Methods

Patients with diabetes mellitus were enrolled in this study. Each study subject underwent two imaging sessions, during which three OCTA images of the macular area and three images of the optic nerve head were obtained. The two sessions took place one year apart. The OCTA imaging was performed using an AngioVue device. Superficial vessel density was evaluated in the central 3 mm and parafoveal area, and the nonflow area was measured using the built-in automated AngioAnalytics software of the Optovue system.

Results

This study included 78 eyes of 39 diabetic patients (age: 55.16 ± 13.73 years) with a mean of 7.70 ± 1.07 mmol L−1 HgA1c level at baseline. At the one-year visit, the eyes of the diabetic subjects had significantly lower superficial vessel density in the parafoveal macula compared to corresponding values at baseline (p < 0.05). There was no statistically significant difference between the baseline and one-year results for the other vascular density parameters and the foveal avascular zone (p > 0.05).

Conclusion

At the one-year follow-up, we found that vessel density had decreased in the parafoveal ring in these patients, while there was no significant change in other vascular parameters. This result suggests that superficial parafoveal capillary density is the most sensitive OCTA parameter that can be used as a biomarker for diabetic retinopathy progression. None of the other vascular density parameters nor the foveal avascular zone were able to indicate the subtle changes in retinal microcirculation due to the progression of diabetic microvasculopathy.

Open access

Kernel samples of two maize hybrids (46308 and 463017) with different levels of resistance to Fusarium ear rot were collected from artificially and naturally infected plants. The spectral characteristics of the samples were analysed with an ASD Fieldspec 3 MAX spectroradiometer in the wavelength range of 350 to 2500 nm using an ex situ method. The different extents of artificial and natural Fusarium infection on the maize kernels resulted in spectral differences detectable with a spectroradiometer. The data showed that for both genotypes the level of Fusarium infection generated by artificial inoculation was significantly higher than that caused by natural infection over a wavelength range of 2030 to 2080 nm. Principal Component Analysis (PCA) on the data set for this range revealed that the first component explained 77.0% of the variability for hybrid 46308 and 97.0% for hybrid 46317.

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This study analyzed the relationship between mechanical force production and spatial arm position of the swimming movement for each side of the swimmer. Eight internationally recognized male swimmers performed fix positioned arm only swimming with a dynamometer synchronized with underwater cameras. The upper arm positions (α in side, β in frontal view) and the elbow angles (γ in 3D) were determined at the moment where the force production reached the peak (Fmax) and the maximal values of rate of force development (RFDmax). RFDmax and α values showed significant differences between the sides (P<0.05). To show the motion integration structure of the performance, Multiple Regression Analysis (MRA) was employed separately for both sides. For the criterion variable, the impulse of force (ImpF50%) was calculated. The defined parameters as the mechanical and spatial predictor system were used for the model. The results of the MRA showed that the predictor system yielded the model structure of the variables that explain the criterion variables for ImpF50% by the dominant (P=0.007) and by the nondominant side (P=0.001), respectively. The alternate contribution of the variables to the models can objectively express the performance difference between the two sides of the swimmer.

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Learning & Perception
Authors:
Alexandra Bendixen
,
Tamás M. Bőhm
,
Orsolya Szalárdy
,
Robert Mill
,
Susan L. Denham
, and
István Winkler

Sound sources often emit trains of discrete sounds, such as a series of footsteps. Previously, two different principles have been suggested for how the human auditory system binds discrete sounds together into perceptual units. The feature similarity principle is based on linking sounds with similar characteristics over time. The predictability principle is based on linking sounds that follow each other in a predictable manner. The present study compared the effects of these two principles. Participants were presented with tone sequences and instructed to continuously indicate whether they perceived a single coherent sequence or two concurrent streams of sound. We investigated the influence of separate manipulations of similarity and predictability on these perceptual reports. Both grouping principles affected perception of the tone sequences, albeit with different characteristics. In particular, results suggest that whereas predictability is only analyzed for the currently perceived sound organization, feature similarity is also analyzed for alternative groupings of sound. Moreover, changing similarity or predictability within an ongoing sound sequence led to markedly different dynamic effects. Taken together, these results provide evidence for different roles of similarity and predictability in auditory scene analysis, suggesting that forming auditory stream representations and competition between alternatives rely on partly different processes.

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Learning & Perception
Authors:
Alexandra Bendixen
,
Tamás M. Bőhm
,
Orsolya Szalárdy
,
Robert Mill
,
Susan L. Denham
, and
István Winkler

Sound sources often emit trains of discrete sounds, such as a series of footsteps. Previously, two different principles have been suggested for how the human auditory system binds discrete sounds together into perceptual units. The feature similarity principle is based on linking sounds with similar characteristics over time. The predictability principle is based on linking sounds that follow each other in a predictable manner. The present study compared the effects of these two principles. Participants were presented with tone sequences and instructed to continuously indicate whether they perceived a single coherent sequence or two concurrent streams of sound. We investigated the influence of separate manipulations of similarity and predictability on these perceptual reports. Both grouping principles affected perception of the tone sequences, albeit with different characteristics. In particular, results suggest that whereas predictability is only analyzed for the currently perceived sound organization, feature similarity is also analyzed for alternative groupings of sound. Moreover, changing similarity or predictability within an ongoing sound sequence led to markedly different dynamic effects. Taken together, these results provide evidence for different roles of similarity and predictability in auditory scene analysis, suggesting that forming auditory stream representations and competition between alternatives rely on partly different processes.

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