Contour Integration Across Polarities and Spatial Gaps: From Local Contrast Filtering to Global Grouping

This article introduces an experimental paradigm to selectively probe the multiple levels of visual processing that influence the formation of object contours, perceptual boundaries, and illusory contours. The experiments test the assumption that, to integrate contour information across space and contrast sign, a spatially short-range filtering process that is sensitive to contrast polarity inputs to a spatially long-range grouping process that pools signals from opposite contrast polarities. The stimuli consisted of thin subthreshold lines, flashed upon gaps between collinear inducers which potentially enable the formation of illusory contours. The subthreshold lines were composed of one or more segments with opposite contrast polarities. The polarity nearest to the inducers was varied to differentially excite the short-range filtering process. The experimental results are consistent with neurophysiological evidence for cortical mechanisms of contour processing and with the Boundary Contour System model, which identifies the short-range filtering process with cortical simple cells, and the long-range grouping process with cortical bipole cells.Office of Naval Research (N00014-95-1-0409, N00014-95-1-0657); Centre National de la Recherche Scientifique (France) URA (1939

Socio-Economic Impact of Artisanal Mining of Blue Sapphire on the Mambilla Plateau

Blue sapphire gemstone has been mined on the Mambilla plateau and traded in different parts of the world including Thailand and Sri Lanka over the years. However, the new Mambilla blue sapphire discovered recently has generated a lot of excitement in the global community because of its high quality. This discovery has led to a general rush by the people in the area mostly youths into artisanal mining of the blue gemstone. This study examines the process of artisanal mining of blue sapphire and the socio-economic impact of the mining on the environment. Data were generated through interviews with key stakeholders. Ethnographic observation of the mining site was conducted during the fieldwork. Information was also collected from relevant secondary sources including reports, books and journal articles. The Information obtained from the individual interviews and focus group discussions was content-analyzed and subjected to descriptive analysis. The finding of the study shows that the artisanal mining of the blue sapphire has created employment opportunity to the teaming jobless youths in the area. This has attracted many people from within and outside the country to the area. Although the mining of the sapphire has created wealth to the people, the negative impacts of the mining is also a major concern as large tract of forest cover and scarce agricultural land in the area are loss in the process of sapphire hunt. This study therefore recommend for the need to put in place framework that integrates the artisanal miners fully into the productive sector of the national economy and advocacy campaign to enlighten artisanal miners on the direct link between their operations and environmental degradation and the need for adoption of sustainable method of mining. Keywords: Artisanal, Blue sapphire, Impact, Mambilla and Socio-economic

Additional Evidence of Post-Kansan Glaciation in Johnson County, Iowa

Johnson County offers a field of phenomena that are strikingly applicable to the theme of our late Pleistocene controversy, namely. “Has the northeast quarter of Iowa, except the Driftless Area, been invaded by an ice-sheet later than the Kansan?

Scholarly Program Notes of Recital Repertoire

This document introduces Jacques Offenbach\u27s Pardieu! C\u27est une aimable charge from La Jolie Parfumeuse, Giacomo Meyerbeer\u27s Ecoutez! Adamastor roi des vagues profondes from L\u27Africaine, Robert Franz\u27s 6 Gesänge, op. 30, Gioachino Rossini\u27s Largo al factotum from Il barbiere di Siviglia, Peter Warlock\u27s The First Mercy, As ever I saw, and Jillian of Berry and J.S. Bach\u27s Ich habe genug, BWV 82. Each of these works is presented with a brief history of its composer as well as relevant historical context and information regarding the origins of their texts. A short analysis of both text and music is included in each chapter

The RING-CH ligase K5 antagonizes restriction of KSHV and HIV-1 particle release by mediating ubiquitin-dependent endosomal degradation of tetherin

Tetherin (CD317/BST2) is an interferon-induced membrane protein that inhibits the release of diverse enveloped viral particles. Several mammalian viruses have evolved countermeasures that inactivate tetherin, with the prototype being the HIV-1 Vpu protein. Here we show that the human herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) is sensitive to tetherin restriction and its activity is counteracted by the KSHV encoded RING-CH E3 ubiquitin ligase K5. Tetherin expression in KSHV-infected cells inhibits viral particle release, as does depletion of K5 protein using RNA interference. K5 induces a species-specific downregulation of human tetherin from the cell surface followed by its endosomal degradation. We show that K5 targets a single lysine (K18) in the cytoplasmic tail of tetherin for ubiquitination, leading to relocalization of tetherin to CD63-positive endosomal compartments. Tetherin degradation is dependent on ESCRT-mediated endosomal sorting, but does not require a tyrosine-based sorting signal in the tetherin cytoplasmic tail. Importantly, we also show that the ability of K5 to substitute for Vpu in HIV-1 release is entirely dependent on K18 and the RING-CH domain of K5. By contrast, while Vpu induces ubiquitination of tetherin cytoplasmic tail lysine residues, mutation of these positions has no effect on its antagonism of tetherin function, and residual tetherin is associated with the trans-Golgi network (TGN) in Vpu-expressing cells. Taken together our results demonstrate that K5 is a mechanistically distinct viral countermeasure to tetherin-mediated restriction, and that herpesvirus particle release is sensitive to this mode of antiviral inhibition

RADICALIZATION IN MOZAMBIQUE: THE RISE OF THE ISLAMIC STATE IN CABO DELGADO

In 2017 Cabo Delgado, Mozambique, saw the rapid rise of a violent Islamist movement that would declare its allegiance to the Islamic State (IS) just one year later. This thesis seeks to establish what factors led to the rise of IS-Mozambique to help recommend a balanced U.S. policy to best address the situation. It compiles economic and environmental data and compares the data with public opinions to determine impacts on the population of Cabo Delgado. Additionally, the thesis utilizes literature relating to the political structure of Mozambique and the interactions of its Muslim population. Findings suggest that Mozambique’s political structure, not economical or environmental issues, best explains the rise of IS-Mozambique. Autocratization by Mozambique Liberation Front has destabilized democratic institutions, leading to increases in violence. It is recommended that the U.S. not provide military support to counter this insurgency, with Mozambique receiving aid from regional countries and the EU.Major, United States Marine CorpsApproved for public release. Distribution is unlimited

Vpu and BST2: Still Not There Yet?

Extensive investigations have identified two cellular proteins in humans that potently inhibit HIV type 1 (HIV-1) replication and are widely accepted as “restriction factors.” APOBEC3G was identified as a restriction factor that diminishes HIV-1 replication by inducing G-to-A hypermutation in the viral genome, while BST2 has been identified as another restriction factor that impairs the release of nascent virions by tethering them on the surface of infected cells. To counter these restriction factors, HIV-1 has equipped itself with its own weapons: viral infectivity factor (Vif) degrades APOBEC3G, while viral protein U (Vpu) antagonizes BST2. These findings have allowed us to further our understanding of virus–host interaction, namely, the interplay between viral factors versus host restriction factors. In the first case, the interplay between APOBEC3G and Vif is clear: vif-deficient HIV-1 is incapable of replicating in APOBEC3G-expressing cells. This insight directly indicates that APOBEC3G is a bona fide restriction factor and has intrinsic immunity against HIV-1, and that Vif is a prerequisite for HIV-1 infection. In other words, the relationship between Vif and APOBEC3G has already “matured,” and Vif has highly evolved to overcome APOBEC3G. On the other hand, although BST2 drastically impairs the release of vpu-deficient HIV-1 virions, it is puzzling that vpu-deficient HIV-1 is still able to replicate in BST2-expressing cells. These insights imply that BST2-mediated anti-HIV-1 activity is vulnerable, and that Vpu is dispensable for HIV-1 infection. If so, why has Vpu acquired the counteracting potential against BST2? Was it necessary or important for HIV-1? Or is the relationship between Vpu and BST2 still “immature”? In this review, we particularly focus on the interplay between Vpu and BST2. We discuss the possibility that Vpu has evolved as a potent antagonist against BST2, and finally, propose a hypothesis that Vpu has evolved as a promoter of human-to-human HIV-1 transmission. Since the first report of acquired immunodeficiency syndrome patients in 1981, HIV-1 has spread explosively worldwide and is currently a pandemic. This review proposes a concept suggesting that the current HIV-1 pandemic may be partly attributed by Vpu

Clermont-Ferrand – Rue Patrick-Depailler, zone de la Pardieu

Le projet d’aménagement situé rue Patrick-Depailler à Clermont-Ferrand (îlot Pardieu) a nécessité la réalisation d’un diagnostic archéologique sur une emprise de 45 630 m2 dont 29 600 m2 étaient accessibles. La zone d’étude se situe à l’altitude moyenne de 346 m NGF sur un terrain plat situé au sud du puy de Crouel. Dans ce secteur, le substrat oligocène est surmonté par une terrasse alluviale de l’Artière et des limons bruns. Les 19 sondages réalisés ont livré les traces de deux grandes..