Stereo and motion parallax cues in human 3D vision: can they vanish without a trace?

In an immersive virtual reality environment, subjects fail to notice when a scene expands or contracts around them, despite correct and consistent information from binocular stereopsis and motion parallax, resulting in gross failures of size constancy (A. Glennerster, L. Tcheang, S. J. Gilson, A. W. Fitzgibbon, & A. J. Parker, 2006). We determined whether the integration of stereopsis/motion parallax cues with texture-based cues could be modified through feedback. Subjects compared the size of two objects, each visible when the room was of a different size. As the subject walked, the room expanded or contracted, although subjects failed to notice any change. Subjects were given feedback about the accuracy of their size judgments, where the “correct” size setting was defined either by texture-based cues or (in a separate experiment) by stereo/motion parallax cues. Because of feedback, observers were able to adjust responses such that fewer errors were made. For texture-based feedback, the pattern of responses was consistent with observers weighting texture cues more heavily. However, for stereo/motion parallax feedback, performance in many conditions became worse such that, paradoxically, biases moved away from the point reinforced by the feedback. This can be explained by assuming that subjects remap the relationship between stereo/motion parallax cues and perceived size or that they develop strategies to change their criterion for a size match on different trials. In either case, subjects appear not to have direct access to stereo/motion parallax cues

NETRC Regional Conference: “Integrating Telehealth”

The Northeast Telehealth Resource Center (NETRC) invites participation in the second annual NETRC conference, "Integrating Telehealth in an Evolving Landscape" to be held September 23-24, 2015 in Burlington, Vermont. This fall, stakeholders from across an eight-state region will gather to learn about telehealth best practice and innovation, network with colleagues, and identify opportunities to advance their telehealth programs

VIP: Finding Important People in Images

People preserve memories of events such as birthdays, weddings, or vacations by capturing photos, often depicting groups of people. Invariably, some individuals in the image are more important than others given the context of the event. This paper analyzes the concept of the importance of individuals in group photographs. We address two specific questions -- Given an image, who are the most important individuals in it? Given multiple images of a person, which image depicts the person in the most important role? We introduce a measure of importance of people in images and investigate the correlation between importance and visual saliency. We find that not only can we automatically predict the importance of people from purely visual cues, incorporating this predicted importance results in significant improvement in applications such as im2text (generating sentences that describe images of groups of people)

Preventing Recurrences of the Cover-Ups at Penn State & Baylor (and now Michigan State): Where Does It End?

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The Physical Chemistry Underlying the Assembly and Midpoint Potential Control in a Series of Designed Protein-Maquettes

In nature, oxidoreductase proteins are responsible for many enzymatic processes critical to life. These proteins often rely on the presence of non-proteinaceous cofactors to take part in the enzymatic function.  The most common, central to my thesis, is heme B.  Depending on the protein environment, this cofactor can take part in functions as diverse as electron transfer (cytochromes), oxygen transport (hemoglobins), oxygen reduction (oxidases), carbon-hydroxylation (oxygenases), and superoxide production (NADH oxidase). In natural oxidoreductases, determination of the course and rates of heme-protein association, what barriers are encountered, what affinity is achieved, and what are the oxidation-reduction potentials, is critical for understanding the rules of assembly and function of the different activities performed. In the growing field of research attempting to make man-made oxidoreductases, the same understanding is required for progress to be made toward construction of novel enzymes. However, this understanding is still out of reach in natural oxidoreductases because of the immense complexity of natural proteins, while for man-made designs progress has only recently reached a point where an in-depth systematic study can be contemplated. My thesis states: Simple non-natural proteins (maquettes) designed from first principles to ligate heme, can be used to uncover the factors derived from the oligomeric and structural state of related maquette and also derived from porphyrin variants of heme B, that govern rates of  incorporation and ligation of heme B into a maquette. Maquettes are ideal platforms to demonstrate what aspects of a protein govern heme redox potentials, a key parameter underlying the diversity of hemoprotein functions.  The findings from my work provide the first views of heme and maquette assembly: spontaneous, rapid and with high affinity association. They also provide a foundation for understanding what controls redox potentials of the heme and perspective on this control. The work offers insight into similar processes in natural oxidoreductases, but the concepts and principles uncovered in this thesis will be vital in the development of novel functions applied in man-made applications in vitro and in vivo

Characterization And Perturbation Of Functional Networks That Support Human Memory

Episodic memory is essential to our daily lives, as it attaches meaning to the constant stream of sensory inputs to the brain. However, episodic memory often fails in a number of common neurocognitive disorders. Effective therapies remain elusive, owing to the complexity of brain networks and neural processes that support episodic encoding and retrieval. In particular, it is not understood how inter-regional communication within the brain supports memory function, though such communication may be critical to the highly integrative nature of episodic memory. To uncover the patterns of memory-related functional connectivity, we asked a large cohort of neurosurgical patients with indwelling electrodes to perform a verbal free-recall task, in which patients viewed lists of simple nouns and recalled them a short time later. As patients performed this task, we collected intracranial EEG (iEEG) from electrodes placed on the cortical surface and within the medial temporal lobe (MTL). First, we examined whole-brain functional networks that emerged during the encoding and retrieval phases of this task, using spectral methods to correlate frequency-specific signals between brain regions. We identified a dynamic network of regions that exhibited enhanced theta (3-8 Hz) connectivity during successful memory processing, whereas regions tended to desynchronize at high frequencies (30-100 Hz). Next, using only electrodes placed within the MTL, we asked whether functional coupling was also observed among this mesoscale subnetwork of highly specialized regions that play an outsize role in memory. Recapitulating our earlier findings, we noted broadly enhanced theta connectivity within the MTL, centering on the left entorhinal cortex during successful encoding operations. Finally, to determine whether such low-frequency functional connections reflect correlative or causal relations in the brain, we applied direct electrical stimulation via electrodes placed within the MTL. We found that low-frequency connections (5-13 Hz) predicted the emergence of theta activity at distant regions in the brain – particularly when stimulation occurred near white matter – indicating the potential causal relevance of iEEG-based functional connections. Taken together, these studies underscore the importance of low-frequency functional coupling to memory across spatial scales, and suggest this form of coupling indicates a causal relation between brain regions

Algebraic symmetries of generic (m+1)(m+1) dimensional periodic Costas arrays

In this work we present two generators for the group of symmetries of the generic $(m+1)$ dimensional periodic Costas arrays over elementary abelian $(\mathbb{Z}_p)^m$ groups: one that is defined by multiplication on $m$ dimensions and the other by shear (addition) on $m$ dimensions. Through exhaustive search we observe that these two generators characterize the group of symmetries for the examples we were able to compute. Following the results, we conjecture that these generators characterize the group of symmetries of the generic $(m+1)$ dimensional periodic Costas arrays over elementary abelian $(\mathbb{Z}_p)^m$ groups