Graham Foundation

The sensitivity of the human visual system is thought to be shaped by environmental statistics. A major endeavor in vision science, therefore, is to uncover the image statistics that predict perceptual and cognitive function. When searching for targets in natural images, for example, it has recently been proposed that target detection is inversely related to the spatial similarity of the target to its local background. We tested this hypothesis by measuring observers’ sensitivity to targets that were blended with natural image backgrounds. Targets were designed to have a spatial structure that was either similar or dissimilar to the background. Contrary to masking from similarity, we found that observers were most sensitive to targets that were most similar to their backgrounds. We hypothesized that a coincidence of phase alignment between target and background results in a local contrast signal that facilitates detection when target-background similarity is high. We confirmed this prediction in a second experiment. Indeed, we show that, by solely manipulating the phase of a target relative to its background, the target can be rendered easily visible or undetectable. Our study thus reveals that, in addition to its structural similarity, the phase of the target relative to the background must be considered when predicting detection sensitivity in natural images.

Visual motion perception underpins behaviors ranging from navigation to depth perception and grasping. Our limited access to biological systems constrains our understanding of how motion is processed within the brain. Here we explore properties of motion perception in biological systems by training a neural network to estimate the velocity of image sequences. The network recapitulates key characteristics of motion processing in biological brains, and we use our access to its structure to explore and understand motion (mis)perception. We find that the network captures the biological response to reverse-phi motion in terms of direction. We further find that it overestimates and underestimates the speed of slow and fast reverse-phi motion, respectively, because of the correlation between reverse-phi motion and the spatiotemporal receptive fields tuned to motion in opposite directions. Second, we find that the distribution of spatiotemporal tuning properties in the V1 and middle temporal (MT) layers of the network are similar to those observed in biological systems. We then show that, in comparison to MT units tuned to fast speeds, those tuned to slow speeds primarily receive input from V1 units tuned to high spatial frequency and low temporal frequency. Next, we find that there is a positive correlation between the pattern-motion and speed selectivity of MT units. Finally, we show that the network captures human underestimation of low coherence motion stimuli, and that this is due to pooling of noise and signal motion. These findings provide biologically plausible explanations for well-known phenomena and produce concrete predictions for future psychophysical and neurophysiological experiments.

Chondrolipoma, a rare variant of a lipoma, is a benign mesenchymal neoplasm characterised by mature adipocytes with neoplastic hyaline cartilage formation. We describe the first case of a gastric chondrolipoma. The tumour was completely excised via laparoscopic gastric wedge resection with uneventful postoperative recovery. Histology of the tumour demonstrates mature adipose tissue and benign cartilage with patchy calcification.

Many experts believe that new supplies of natural gas and oil from shale and other unconventional formations have the potential to decrease our energy costs, boost our economies, enhance our national security, and reduce our greenhouse gas emissions. These new natural gas and oil supplies are being unlocked through the application of hydraulic fracturing and horizontal drilling, which are dramatically increasing energy production across the United States and creating opportunities for similar development in other countries like Australia. But expanding oil and gas production is also stimulating global concerns about potential adverse impacts to water, air, and other resources, which are the subject of proliferating study and regulatory attention. This presentation will summarise the wide range of benefits and concerns associated with shale development in the United States. It will suggest emerging regulatory trends at the state and national levels, which may help to shape the approach of other countries, such as seeking incremental improvement, better balancing prescription and performance, and improving interagency coordination. It will describe the experience of states like Colorado, which are producing more of the energy we need while doing a better job of protecting the environment we treasure. And it will explore how responsible regulation can help us bridge the widening gap between the pivotal promise and the perceived peril of unconventional oil and gas development.

Background: The 5-lipoxygenase inhibitor VIA-2291 effectively lowers production of leukotriene metabolites. This study investigates the relations between inflammation, coronary plaque characteristics and left ventricular function in response to treatment with VIA-2291 (Atreleuton) in patients after an acute coronary syndrome (ACS). Methods: Fifty six post-ACS patients who participated in a randomized trial evaluating the effects of VIA-2291 vs. placebo and underwent cardiac computed tomography angiography were studied. Leukotriene E4 (LTE4), high-sensitivity C-reactive protein (hs-CRP), coronary plaque volume (PV) with vulnerable characteristics (Necrotic Core) and left ventricular ejection fraction (LVEF) were measured at baseline and at 6-month follow-up. The relation of changes in LTE4, hs-CRP, PV and LVEF in response to VIA-2291 was analyzed using conditional logistic regression analyses. Results: From baseline to 6 months, after adjustment for risk factors, significant reductions in LTE4, hs-CRP and VP, and an increase in LVEF with VIA-2991 as compared to placebo were noted (p<0.05, Table).After adjustment for risk factors, there were strong associations between the decrease in LTE4, the decrease in necrotic core PV and the increase in LVEF (Table); 71% and 79% of the variance in PV and LVEF was explained by the decrease in LTE4 in response to VIA-2991 (p<0.05). The maximum improvement in LVEF was noted with maximum decrease in LTE4 and PV. Conclusion: This study documented a strong relation between decreases in LTE4, decreases in necrotic core coronary plaque volume and improved LV function in response to VIA-2291.

Previous articleNext article No AccessBook ReviewThe Market and the City: Square, Street, and Architecture in Early Modern Europe. By Donatella Calabi. Translated by Marlene Klein. Historical Urban Studies. Edited by Richard Rodger and Jean‐Luc Pinol. Burlington, VT: Ashgate, 2004. Pp. xxvii+217. $109.95.Stephanie WhitlockStephanie WhitlockGraham Foundation for Advanced Studies in the Fine Arts Search for more articles by this author Graham Foundation for Advanced Studies in the Fine ArtsPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Journal of Modern History Volume 79, Number 3September 2007 Article DOIhttps://doi.org/10.1086/523218 Views: 62Total views on this site Citations: 1Citations are reported from Crossref Permission to reprint a book review printed in this section may be obtained only from the author.PDF download Crossref reports the following articles citing this article:Qi Meng, Tingting Zhao, Jian Kang , Frontiers in Psychology 9 ( 2018).https://doi.org/10.3389/fpsyg.2018.00596

ABSTRACT This paper presents a summary of the key observations and conclusions from the Gas Research Institute's (GRI's) Comprehensive Study Well (CSW) research program conducted in the Devonian Shales of the Appalachian Basin. Initiated in 1987, the CSW program was a series of highly instrumented study wells drilled in cooperation with industry partners. Seven wells were drilled as part of the program. Extensive data sets were collected and special experiments were run on the CSW's in addition to the operator's normal operations, with the objectives of identifying geologic production controls, refining formation evaluation tools, and improving reservoir description and stimulation practices in the Devonian Shales. This paper highlights the key results from the research conducted in the CSW program in the areas of geologic production controls, formation evaluation, stimulation and reservoir engineering, and field operations. The development of geologic, log analysis, and reservoir models for the Shales from the data gathered and analyzed during the research is discussed. In addition, on the basis of what was learned in the CSW program, GRI's plans for new research in the Devonian Shales are described.