189 research outputs found
Individual variation in inter-ocular suppression and sensory eye dominance
The competitive and inhibitory interactions between the two eyesâ images are a pervasive aspect of binocular vision. Over the last decade, our understanding of the neural processes underpinning binocular rivalry (BR) and continuous flash suppression CFS) has increased substantially, but we still have little understanding of the relationship between these two effects and their variation in the general population. Studies that pool data across individuals and eyes risk masking substantial variations in binocular vision that exist in the general population. To investigate this issue we compared the depth of inter-ocular suppression evoked by BR with that elicited by CFS, in a group (N=25) of visually normal individuals. A noise pattern (either static for BR or dynamic for CFS) was presented to one eye and its suppressive influence on a probe grating presented simultaneously to the other eye was measured. We found substantial individual differences in the magnitude of suppression (a 10-fold variation in probe detection threshold) evoked by each task, but performance on BR was a significant predictor of performance on the CFS task. However many individuals showed marked asymmetries between the two eyesâ ability to detect a suppressed target, that were not necessarily the same for the two tasks. There was a tendency for the magnitude of the asymmetry to increase as the refresh rate of the dynamic noise increased. The results suggest a common underlying mechanism is likely to be responsible, at least in part, for driving inter-ocular suppression under BR and CFS. The marked asymmetries in inter-ocular suppression at higher noise refresh rates, may be indicative of a difference in temporal processing between the eyes
Profitability and Data-Snooping Tests of Four Technical Trade Strategies for Cryptocurrency Pair BTC/USDT and ETH/USDT in Cryptocurrency Markets During 2022â2023
We provide a comprehensive investigation into the profitability of technical trading methods applied to the cryptocurrency pairs BTC/USDT and ETH/USDT. By employing rigorous evaluations and incremental examinations, we address the pervasive issue of data-snooping bias that often plagues the evaluation of trading strategies. Our empirical results indicate the lack of profitable technical trading strategies in both the analysis sample and prediction sample periods, even after rigorous adjustments for data snooping. These findings highlight the difficulties associated with selecting profitable technical trading strategies in the dynamic and volatile cryptocurrency market. Market participants, including individual traders, institutional investors, and regulatory bodies, should take note of our findings when making investment decisions based on technical analysis
Effects of antipsychotics on bone mineral density and prolactin levels in patients with schizophrenia: a 12-month prospective study
Objective: Effects of conventional and atypical antipsychotics on bone mineral density (BMD) and serum prolactin levels (PRL) were examined in patients with schizophrenia.Methods: One hundred and sixty-three first-episode inpatients with schizophrenia were recruited, to whom one of three conventional antipsychotics (perphenazine, sulpiride, and chlorpromazine) or one of three atypical antipsychotics (clozapine, quetiapine, and aripiprazole)was prescribed for 12 months as appropriate. BMD and PRL were tested before and after treatment. Same measures were conducted in 90 matched healthy controls.Results Baseline BMD of postero-anterior L1âL4 range from 1.04 ± 0.17 to 1.42 ± 1.23, and there was no significant difference between the patients group and healthy control group. However, post-treatment BMD values in patients (ranging from 1.02 ± 0.15 to 1.23 ± 0.10) were significantly lower than that in healthy controls (ranging from 1.15 ± 0.12 to 1.42 ± 1.36). The BMD values after conventional antipsychotics were significantly lower than that after atypical antipsychotics. The PRL level after conventional antipsychotics (53.05 ± 30.25 ng/ml) was significantly higher than that after atypical antipsychotics (32.81 ± 17.42 ng/ml). Conditioned relevance analysis revealed significant negative correlations between the PRL level and the BMD values after conventional antipsychotics.Conclusion The increase of PRL might be an important risk factor leading to a high prevalence of osteoporosis in patients with schizophrenia on long-term conventional antipsychotic medication.<br/
Collective plasticity of binocular interactions in the adult visual system
Binocular visual plasticity can be initiated via either bottom-up or top-down mechanisms, but it is unknown if these two forms of adult plasticity can be independently combined. In seven participants with normal binocular vision, sensory eye dominance was assessed using a binocular rivalry task, before and after a period of monocular deprivation and with and without selective attention directed towards one eye. On each trial, participants reported the dominant monocular target and the inter-ocular contrast difference between the stimuli was systematically altered to obtain estimates of ocular dominance. We found that both monocular light- and pattern-deprivation shifted dominance in favour of the deprived eye. However, this shift was completely counteracted if the non-deprived eyeâs stimulus was selectively attended. These results reveal that shifts in ocular dominance, driven by bottom-up and top-down selection, appear to act independently to regulate the relative contrast gain between the two eyes
Inter-ocular Suppression and Sensory Eye Dominance in Human Vision
Inter-ocular interactions are a crucial component of binocular vision, providing important insights into how the inputs from the two eyes are combined and compete with each other. This aspect was addressed in a series of psychophysical experiments by investigating inter-ocular suppression and sensory eye dominance in the normal visual system. Firstly, patterns of individual differences, and variations in sensory eye dominance, in terms of susceptibility to binocular rivalry (BR) and continuous flash suppression (CFS), were established in a representative sample of participants. The results indicate that there may be a common mechanism underpinning these inter-ocular suppression phenomena, whilst sensory eye dominance associated with depth of suppression may be task dependent. Furthermore, this thesis has also demonstrated the adjustment of sensory eye dominance following short periods of monocular deprivation/distortion in the adult visual system. Crucially, it has been shown that changes in sensory eye dominance resulted specifically from reduced inter-ocular suppression of the previously treated eye. Moreover, the present findings underscore a role of inter-ocular imbalance in the visual processing, arising from both low-level sensory input and higher-level processes, in altering subsequent sensory eye dominance. Taken together, the findings of this thesis imply that there is a mechanism that detects inter-ocular conflict, which in turn elicits inter-ocular inhibition that is sensitive to imbalance between the two eyes' processing. These findings have contributed new knowledge to the understanding of inter-ocular interactions, and placed important constraints on the models of binocular vision
Spectral Ranking Inferences based on General Multiway Comparisons
This paper studies the performance of the spectral method in the estimation
and uncertainty quantification of the unobserved preference scores of compared
entities in a very general and more realistic setup in which the comparison
graph consists of hyper-edges of possible heterogeneous sizes and the number of
comparisons can be as low as one for a given hyper-edge. Such a setting is
pervasive in real applications, circumventing the need to specify the graph
randomness and the restrictive homogeneous sampling assumption imposed in the
commonly-used Bradley-Terry-Luce (BTL) or Plackett-Luce (PL) models.
Furthermore, in the scenarios when the BTL or PL models are appropriate, we
unravel the relationship between the spectral estimator and the Maximum
Likelihood Estimator (MLE). We discover that a two-step spectral method, where
we apply the optimal weighting estimated from the equal weighting vanilla
spectral method, can achieve the same asymptotic efficiency as the MLE. Given
the asymptotic distributions of the estimated preference scores, we also
introduce a comprehensive framework to carry out both one-sample and two-sample
ranking inferences, applicable to both fixed and random graph settings. It is
noteworthy that it is the first time effective two-sample rank testing methods
are proposed. Finally, we substantiate our findings via comprehensive numerical
simulations and subsequently apply our developed methodologies to perform
statistical inferences on statistics journals and movie rankings
Consumersâ Adopt Intention for Contactless Delivery during COVID-19: An Extended Perspective on The Theory of Planned Behavior
COVID-19 is a severe disease and has now spread around the world as a highly infectious pandemic. COVID-19 has rapidly and deeply affected our daily life, and most countries have taken measures to prevent the spread of this disease, such as restricting entry and centralized isolation. Contactless delivery is a non-face-to-face delivery method which help ensure sufficient distance between the rider and the customers, thus further reduces the pandemic transmission risk. While relatively few people know and adopt this service. This study used the theory of planned behaviour to investigate peopleâs intention to adopt contactless home delivery services during COVID-19. Research results provide both contributions to academics and practitioners
Zonal Soil Type Determines Soil Microbial Responses to Maize Cropping and Fertilization.
Soil types heavily influence ecological dynamics. It remains controversial to what extent soil types shape microbial responses to land management changes, largely due to lack of in-depth comparison across various soil types. Here, we collected samples from three major zonal soil types spanning from cold temperate to subtropical climate zones. We examined bacterial and fungal community structures, as well as microbial functional genes. Different soil types had distinct microbial biomass levels and community compositions. Five years of maize cropping (growing corn or maize) changed the bacterial community composition of the Ultisol soil type and the fungal composition of the Mollisol soil type but had little effect on the microbial composition of the Inceptisol soil type. Meanwhile, 5 years of fertilization resulted in soil acidification. Microbial compositions of the Mollisol and Ultisol, but not the Inceptisol, were changed and correlated (P < 0.05) with soil pH. These results demonstrated the critical role of soil type in determining microbial responses to land management changes. We also found that soil nitrification potentials correlated with the total abundance of nitrifiers and that soil heterotrophic respiration correlated with the total abundance of carbon degradation genes, suggesting that changes in microbial community structure had altered ecosystem processes. IMPORTANCE Microbial communities are essential drivers of soil functional processes such as nitrification and heterotrophic respiration. Although there is initial evidence revealing the importance of soil type in shaping microbial communities, there has been no in-depth, comprehensive survey to robustly establish it as a major determinant of microbial community composition, functional gene structure, or ecosystem functioning. We examined bacterial and fungal community structures using Illumina sequencing, microbial functional genes using GeoChip, microbial biomass using phospholipid fatty acid analysis, as well as functional processes of soil nitrification potential and CO2 efflux. We demonstrated the critical role of soil type in determining microbial responses to land use changes at the continental level. Our findings underscore the inherent difficulty in generalizing ecosystem responses across landscapes and suggest that assessments of community feedback must take soil types into consideration. Author Video: An author video summary of this article is available
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