Variations in retinal photoreceptor topography and the organization of the rod-free zone reflect behavioral diversity in Australian passerines

2015 ◽  
Vol 523 (7) ◽  
pp. 1073-1094 ◽  
Author(s):  
João Paulo Coimbra ◽  
Shaun P. Collin ◽  
Nathan S. Hart
Author(s):  
W. Krebs ◽  
I. Krebs

Various inclusion bodies occur in vertebrate retinal photoreceptor cells. Most of them are membrane bound and associated with phagocytosis or they are age related residual bodies. We found an additional inclusion body in foveal cone cells of the baboon (Papio anubis) retina.The eyes of a 15 year old baboon were fixed by immersion in cacodylate buffered glutaraldehyde (2%)/formaldehyde (2%) as described in detail elsewhere . Pieces of retina from various locations, including the fovea, were embedded in epoxy resin such that radial or tangential sections could be cut.Spindle shaped inclusion bodies were found in the cytoplasm of only foveal cones. They were abundant in the inner segments, close to the external limiting membrane (Fig. 1). But they also occurred in the outer fibers, the perikarya, and the inner fibers (Henle’s fibers) of the cone cells. The bodies were between 0.5 and 2 μm long. Their central diameter was 0.2 to 0. 3 μm. They always were oriented parallel to the long axis of the cone cells. In longitudinal sections (Figs. 2,3) they seemed to have a fibrous skeleton that, in cross sections, turned out to consist of plate-like (Fig.4) and tubular profiles (Fig. 5).


Author(s):  
Diane M. Vanderwalker

There is a widespread interest in understanding the properties of Al-base alloys so that progress can be made toward extending their present applications in the aircraft industry. Al-Zn-Mg is precipitation hardened to gain its high strength; however, during aging the formation of heterogeneous precipitates on the grain boundaries creates a precipitate-free zone in the adjacent region. Since high angle grain boundaries are not easily characterized, it is difficult to establish a relationship between the precipitate and the boundary structure. Therefore, this study involves precipitation on low angle grain boundaries where the boundary and the precipitate can be fully analyzed.


2017 ◽  
Vol 12 (2) ◽  
pp. 297-315 ◽  
Author(s):  
Julian Hanna

Aside from the familiar story of Vorticists and Imagists before the war, no detailed analysis of manifestos in Britain (or Ireland) exists. It is true that, by 1914, there had been such an upsurge in manifesto writing that a review of BLAST in The Times (1 July 1914) began: ‘The art of the present day seems to be exhausting its energies in “manifestoes.”’ But after the brief fire ignited by the arrival of Italian Futurism died out, Britain again became a manifesto-free zone. Or did it? While a mania for the militant genre did not take hold in Britain and Ireland the same way it did in France, Italy, Germany, or Russia, the manifesto did enjoy a small but dedicated following that included Whistler, Wilde, and Yeats; Patrick Geddes and Hugh MacDiarmid; Wyndham Lewis and Ezra Pound; Dora Marsden and Virginia Woolf; and Auden, MacNeice, and Spender. Through these and other figures it is possible to trace the development of a manifesto tradition specific to Britain and Ireland.


Author(s):  
Deirdre Curtin
Keyword(s):  
The Uk ◽  

UK involvement in the EU Area of Freedom, Security, and Justice (AFSJ) has been patchy. It never joined the Schengen border-free zone, and when in 2014 it exercised a block exit from all AFSJ measures, it selectively rejoined a substantial number. Even if partially outside, the UK has been a leader inside. Advanced intelligence capabilities meant it provided important support to the functioning of agencies such as Europol and UK laws inspired EU laws, for example, on data retention. The need to preserve some pragmatic forms of cooperation between the UK and the EU is obvious and shared by the UK security establishment. There is a partial institutional precedent . When Denmark rejected participation in Europol in a popular referendum, the Danish government obtained a deal from the EU institutions which allows it to remain associated to Europol as a ‘third country’ (and a Member State). The bespoke Brexit reality may prove even more complex.


Author(s):  
Yong Wang ◽  
Andrey Karasev ◽  
Joo Hyun Park ◽  
Wangzhong Mu ◽  
Pär G. Jönsson

AbstractChromium is normally added to liquid alloy in the form of different grades of ferrochromium (FeCr) alloys for the requirement of different alloy grades, such as stainless steels, high Cr cast iron, etc.. In this work, inclusions in two commercially produced alloys, i.e., high-carbon ferrochromium (HCFeCr) and low-carbon ferrochromium (LCFeCr) alloys, were investigated. The FeCr alloy/liquid iron interactions at an early stage were investigated by inserting solid alloy piece into contact with the liquid iron for a predetermined time using the liquid-metal-suction method. After quenching these samples, a diffusion zone between the alloys and the liquid Fe was studied based on the microstructural characterizations. It was observed that Cr-O-(Fe) inclusions were formed in the diffusion zone, FeOx inclusions were formed in the bulk Fe, and an “inclusion-free” zone was detected between them. Moreover, it was found that the HCFeCr was slowly dissolved, but LCFeCr alloy was rapidly melted during the experiment. The dissolution and melting behaviors of these two FeCr alloys were compared and the mechanism of the early-stage dissolution process of FeCr alloys in the liquid Fe was proposed.


2006 ◽  
Vol 54 (12) ◽  
pp. 4141-4147 ◽  
Author(s):  
Alejandro Hernández ◽  
Alberto Martín ◽  
Emilio Aranda ◽  
Teresa Bartolomé ◽  
María de Guía Córdoba

1987 ◽  
Vol 33 (115) ◽  
pp. 300-310 ◽  
Author(s):  
T.J.H. Chinn ◽  
A. Dillon

Abstract“Whisky Glacier” on James Ross Island, Antarctic Peninsula, comprises anévéand clean ice trunk surrounded by an extensive area of debris-covered ice resembling a rock glacier. The debris-free trunk of the glacier abuts abruptly against the broad, totally debris-covered tongue at a number of concentric zones where debris-laden beds crop out at the surface in a manner similar to the “inner moraine” formations of many polar glaciers.Ice structures and foliation suggest that “Whisky Glacier” is a polythermal glacier which is wet-based under the debris-free zone, and dry-based under the debris-covered zone. It is surmised that the glacier sole crosses the freezing front close to where the basal debris beds are upwarped towards the surface. Here, basal water is confined, and freezes to the under side of the glacier in thick beds of regelation ice which are uplifted to the surface along with the debris-laden beds. Ablation losses effectively cease beneath the blanket of debris covering the tongue.The transition from wet-based to dry-based conditions at the glacier sole is a powerful mechanism for entraining debris into a glacier and, in the case of “Whisky Glacier”, for lifting debris to the surface. It is suggested that this may be a mechanism for forming some polar rock glaciers.


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