منابع مشابه
A Siphon Hypothesis Goes Down the Tube
So-called neurovascular coupling reflects local blood flow changes that accompany neuronal activity. Not only is this a homeostatic metabolic mechanism, but it also serves as the basis for functional brain imaging. The theory goes that glia cells siphon activity-generated extracellular potassium ions to glial endfeet abutting small blood vessels, leading to vessel relaxation. Not so, say Metea ...
متن کاملCorrigendum: The height limit of a siphon
We wish to acknowledge a related 1995 experiment performed by Andrew K Fletcher (http://inclinedbedtherapy. com), in which a 48 m length of 6 mm bore tubing, filled with degassed water was lifted 24 m vertical against Brixham Cliffs. A 50 ml bolus of coloured saline solution in the middle of the 48 m tubing was introduced prior to the tubing being raised to 24 metres vertical by its centre as a...
متن کاملThe height limit of a siphon
The maximum height of a siphon is generally assumed to be dependent on barometric pressure-about 10 m at sea level. This limit arises because the pressure in a siphon above the upper reservoir level is below the ambient pressure, and when the height of a siphon approaches 10 m, the pressure at the crown of the siphon falls below the vapour pressure of water causing water to boil breaking the co...
متن کاملLocation as a Poverty Trap
In this paper, we ask “Can proximity to towns reduces poverty in rural areas?” For this study we have mapped all the villages in Orissa. The study is based on small area poverty estimation methodology as well as the secondary data covering 47,395 villages and 109 towns. Our main findings are (i) there is a relationship between the distance to nearest town and rural poverty and (ii) poverty leve...
متن کاملCalcification of the carotid siphon.
CALCIFICATION of the internal carotid artery in the region of the cavernous sinus is an extremely common radiologic finding.' Although it is the only readily available laboratory criterion of cerebrovascular disease its significance has never been determined by combined clinical, radiologic, and pathologic studies. Whether the arterial changes in this region, which we shall refer to as the siph...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1887
ISSN: 0036-8733
DOI: 10.1038/scientificamerican10011887-9796asupp