 | Archaeologists excavating Santa Ana Cave (Cáceres, Extremadura, Spain), searching for new archaeological levels and the end of the sediment deposits. "Excavation" usually refers to the exposure, processing and recording of archaeological remains. Photo credit: Mario Modesto MataRecently featured: Yellow-faced Honeyeater – Louis Armstrong – Metriorrhynchus rhipidius |
August 6: Feast of the Transfiguration in Christianity; Independence Day in Bolivia (1825) and Jamaica (1962)
From Wikipedia's newest articles:
Phagocytes are the white blood cells that protect the body by ingesting (phagocytosing) harmful foreign particles, bacteria and dead or dying cells. They are essential for fighting infections, and for subsequent immunity. Phagocytes are important throughout the animal kingdom, and are highly developed in vertebrates. One liter of human blood contains about six billion phagocytes. Phagocytes were first discovered in 1882 by Ilya Ilyich Mechnikov while he was studying starfish larvae. Phagocytes of humans and other animals are called professional or non-professional, depending on how effective they are at phagocytosis. The professional phagocytes include cells called neutrophils, monocytes, macrophages, dendritic cells, and mast cells. The main difference between professional and non-professional phagocytes is that the professional phagocytes have molecules called receptors on their surfaces that can detect harmful objects, such as bacteria, that are not normally found in the body. Phagocytes are therefore crucial in fighting infections, as well as in maintaining healthy tissues by removing dead and dying cells that have reached the end of their life-span. During an infection, chemical signals attract phagocytes to places where the pathogen has invaded the body. (more...)
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The Red River Trails were a network of ox cart routes connecting the Red River Colony and Fort Garry in British North America, with the head of navigation on the Mississippi River in the United States. These trade routes ran from the location of present-day Winnipeg in the Canadian province of Manitoba across the international border and by a variety of routes across what is now the eastern part of North Dakota and western and central Minnesota to Mendota and Saint Paul, Minnesota on the Mississippi. Travellers began to use the trails by the 1820s, with the heaviest use from the 1840s to the early 1870s, when they were superseded by railways. They gave the Selkirk colonists and their neighbours, the Métis people, an outlet for their furs and a source of supplies other than the Hudson's Bay Company, which was unable to enforce its monopoly in the face of the competition that used the trails. Free traders, independent of the Hudson's Bay Company and outside its jurisdiction, developed extensive commerce with the United States, making Saint Paul the principal entrepôt and link to the outside world for the Selkirk Settlement. That corridor has now seen a resurgence of traffic, carried by more modern means of transport than the crude ox carts that once travelled the Red River Trails. (more...)
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