Depth perception not found in human observers for static or dynamic anti-correlated random dot stereograms

One of the greatest challenges in visual neuroscience is that of linking neural activity with perceptual experience. In the case of binocular depth perception, important insights have been achieved through comparing neural responses and the perception of depth, for carefully selected stimuli. One of the most important types of stimulus that has been used here is the anti-correlated random dot stereogram (ACRDS). In these stimuli, the contrast polarity of one half of a stereoscopic image is reversed. While neurons in cortical area V1 respond reliably to the binocular disparities in ACRDS, they do not create a sensation of depth. This discrepancy has been used to argue that depth perception must rely on neural activity elsewhere in the brain. Currently, the psychophysical results on which this argument rests are not clear-cut. While it is generally assumed that ACRDS do not support the perception of depth, some studies have reported that some people, some of the time, perceive depth in some types of these stimuli. Given the importance of these results for understanding the neural correlates of stereopsis, we studied depth perception in ACRDS using a large number of observers, in order to provide an unambiguous conclusion about the extent to which these stimuli support the perception of depth. We presented observers with random dot stereograms in which correlated dots were presented in a surrounding annulus and correlated or anti-correlated dots were presented in a central circular region. While observers could reliably report the depth of the central region for correlated stimuli, we found no evidence for depth perception in static or dynamic anti-correlated stimuli. Confidence ratings for stereoscopic perception were uniformly low for anti-correlated stimuli, but showed normal variation with disparity for correlated stimuli. These results establish that the inability of observers to perceive depth in ACRDS is a robust phenomenon

Le test de McKenzie-Stoughton: méthode de mesure de l’effect réservoir

A la suite de I'observation que firent Mac Kenzie et Stoughton en 1962, montrant que I'application locale de cortico'ldes anti-inflammatoires peut produire un blanchiment de la peau, des tests ont ete mis au point pour apprecier la constitution d'une telle paleur chez des sujets volontaires. Les techniques qui ont ete publiees sont variables quant a la methode d'application (avec ou sans occlusion), la duree d'application du cortico'lde (.c'est-a-dire duree breve de 6 a 8 heures ou prolongee de 16 a 20 heures) et quant a la methode d'appreciation de la reponse, enregistree par exemple comme etant presente ou absente, ou bien cotee, soit avec une simple lecture,. soit avec des lectures repetees, pendant un certain temps. Les auteurs ont mis au point des essais standart de vasoconstriction avec et sans occlusion, pour apprecier les preparations quant a leur efficacite clinique pour determiner la biodisponibilite des cortico'ldes a partir des supports pour applications locales. A condition que I'investigateur et Ie volontaire se conforment strictement au protocole du test les methodes suivantes ont une precision surprenante d'appreciation (Barry et Woodford, 1978)

Possible dosage regimens for topical steroids assessed by vasoconstrictor assays using multiple applications

The bioavailabilities and activities of three amcinonide preparations and Betnovate cream were assessed using three multiple-dosage regimen vasoconstrictor assays in 10 volunteers. Applications were made once daily, twice daily and every alternate day with an initial three times daily loading dose applied on the first day only. Blanching responses first increased and then decreased due to tachyphylaxis. It is proposed that clinically the most advantageous dosage regimen is a once daily application with no loading dose

Implementation of a local principal curves algorithm for neutrino interaction reconstruction in a liquid argon volume

A local principal curve algorithm has been implemented in three dimensions for automated track and shower reconstruction of neutrino interactions in a liquid argon time projection chamber. We present details of the algorithm and characterise its performance on simulated data sets.Comment: 14 pages, 17 figures; typing correction to Eq 5, the definition of the local covariance matri

Green Care: a Conceptual Framework. A Report of the Working Group on the Health Benefits of Green Care

‘Green Care’ is a range of activities that promotes physical and mental health and well-being through contact with nature. It utilises farms, gardens and other outdoor spaces as a therapeutic intervention for vulnerable adults and children. Green care includes care farming, therapeutic horticulture, animal assisted therapy and other nature-based approaches. These are now the subject of investigation by researchers from many different countries across the world

Membrane glycomics reveal heterogeneity and quantitative distribution of cell surface sialylation.

Given that unnatural sugar expression is metabolically achieved, the kinetics and disposition of incorporation can lend insight into the temporal and localization preferences of sialylation across the cell surface. However, common detection schemes lack the ability to detail the molecular diversity and distribution of target moieties. Here we employed a mass spectrometric approach to trace the placement of azido sialic acids on membrane glycoconjugates, which revealed substantial variations in incorporation efficiencies between N-/O-glycans, glycosites, and glycosphingolipids. To further explore the propensity for sialylation, we subsequently mapped the native glycome of model epithelial cell surfaces and illustrate that while glycosylation sites span broadly across the extracellular region, a higher number of heterogeneous glycoforms occur on sialylated sites closest to the transmembrane domain. Beyond imaging techniques, this integrative approach provides unprecedented details about the frequency and structure-specific distribution of cell surface sialylation, a critical feature that regulates cellular interactions and homeostatic pathways

Strain control of magnetic anisotropy in (Ga,Mn)As microbars

We present an experimental and theoretical study of magnetocrystalline anisotropies in arrays of bars patterned lithographically into (Ga,Mn)As epilayers grown under compressive lattice strain. Structural properties of the (Ga,Mn)As microbars are investigated by high-resolution X-ray diffraction measurements. The experimental data, showing strong strain relaxation effects, are in good agreement with finite element simulations. SQUID magnetization measurements are performed to study the control of magnetic anisotropy in (Ga,Mn)As by the lithographically induced strain relaxation of the microbars. Microscopic theoretical modeling of the anisotropy is performed based on the mean-field kinetic-exchange model of the ferromagnetic spin-orbit coupled band structure of (Ga,Mn)As. Based on the overall agreement between experimental data and theoretical modeling we conclude that the micropatterning induced anisotropies are of the magnetocrystalline, spin-orbit coupling origin.Comment: 11 pages, 18 figure

Package fertilizer and the Missouri fertilizer law

Caption title.Digitized 2006 AES MoU

The Missouri Fertilizer Law

Caption title.Digitized 2006 AES MoU