959 resultados para Military vessels.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

“Red coats and wild birds: military culture and ornithology across the nineteenth-century British Empire” investigates the intersections between British military culture and the practices and ideas of ornithology, with a particular focus on the British Mediterranean. Considering that British officers often occupied several imperial sites over the course of their military careers, to what extent did their movements shape their ornithological knowledge and identities at “home” and abroad? How did British military naturalists perceive different local cultures (with different attitudes to hunting, birds, field science, etc.) and different local natures (different sets of birds and environments)? How can trans-imperial careers be written using not only textual sources (for example, biographies and personal correspondence) but also traces of material culture? In answering these questions, I centre my work on the Mediterranean region as a “colonial sea” in the production of hybrid identities and cultural practices, and the mingling of people, ideas, commodities, and migratory birds. I focus on the life geographies of four military officers: Thomas Wright Blakiston, Andrew Leith Adams, L. Howard Lloyd Irby, and Philip Savile Grey Reid. By the mid-nineteenth century, the Mediterranean region emerged as a crucial site for the security of the British “empire route” to India and South Asia, especially with the opening of the Suez Canal in 1869. Military stations served as trans-imperial sites, connecting Britain to India through the flow of military manpower, commodities, information, and bodily experiences across the empire. By using a “critical historical geopolitics of empire” to examine the material remnants of the “avian imperial archive,” I demonstrate how the practices and performances of British military field ornithology helped to: materialize the British Mediterranean as a moral “semi-tropical” place for the physical and cultural acclimatization of British officers en route to and from India; reinforce imperial presence in the region; and make “visible in new ways” the connectivity of North Africa to Europe through the geographical distribution of birds. I also highlight the ways in which the production of ornithological knowledge by army officers was entwined with forms of temperate martial masculinity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Recent electrophysiological studies have suggested that there is a subpopulation of cells in lymphatic vessels which act as pacemakers controlling the characteristic spontaneous contractile activity in this tissue. In this study, electron microscopy and immunohistochemical techniques were used on sheep mesenteric lymphatic vessels to investigate the morphology of the cells comprising the lymphatic wall. The smooth muscle cells were not orientated in circular and longitudinal layers as is seen in the gastrointestinal tract, but were arranged in bundles which interlock and cross over in a basket-weave fashion. Antibodies to Kit and vimentin, which are widely used to label specialised pacemaking cells in the gastrointestinal tract (known as interstitial cells of Cajal), demonstrated the existence of an axially orientated subpopulation of cells lying between the endothelium and the bulk of the smooth muscle. Examination of this area using electron microscopy showed cells which were electron dense compared to the underlying smooth muscle and contained caveolae, Golgi complexes, mitochondria, 10-nm filaments, a well-developed endoplasmic reticulum and a basal lamina. The smooth muscle cells typically contained caveolae, dense bodies, mitochondria, abundant filaments, sER and basal laminae. Cells dispersed for patch-clamp studies were also stained for vimentin and myosin. Myosin-staining cells had the typical spindle appearance of smooth muscle cells whereas the vimentin-positive cells could either be branched or more closely resemble the smooth muscle cells. The present study provides the first morphological evidence that specialised cells exist within the vascular system which have the ultrastructural characteristics of pacemaker cells in other tissues and are vimentin and Kit positive.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador: