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Topic: Root pressure

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	Plant Transport Lecture
		Root pressure is observable at night when evaporation is low and excess water collects in droplets around special openings near the tip of grass blades.
		The gradient is highest in the water surrounding the roots and lowest in the air space within the spongy parenchyma of the leaf.
		Sugar stored in roots may be mobilized to become a source of food in the early spring when the buds of trees, the sink, need energy for growth and development of the photosynthetic apparatus.
	home.earthlink.net /~dayvdanls/plant_transport.html (2016 words)

	Biology 2402 Lecture Notes - Water Transport
		Root pressure is created by the osmotic pressure of xylem sap which is, in turn, created by dissolved minerals and sugars that have been actively transported into the apoplast of the stele.
		Although root pressure plays a role in the transport of water in the xylem in some plants and in some seasons, it does not account for most water transport.
		The volume of fluid transported by root pressure is not enough to account for the measured movement of water in the xylem of most trees and vines.
	www.ualr.edu /botany/transpiration.html (1580 words)

	Water and Mineral Transport
		Seawater is markedly hypertonic to the cytoplasm in the roots of the coastal mangrove, and we might expect water to leave the cells resulting in a loss in turgor and wilting.
		Root pressure is created by the osmotic pressure of xylem sap which is, in turn, created by dissolved
		The highest root pressures occur in the spring when the sap is strongly hypertonic to soil water, but the rate of transpiration is low.
	home.comcast.net /~john.kimball1/BiologyPages/X/Xylem.html (1631 words)

	Introduction to Decibels: Science of Sound in the Sea
		The root-mean-square pressure is most often used to characterize a sound wave because it is directly related to the energy carried by the sound wave, which is called the intensity.
		Finally, the square root of the average of the squared pressures is taken to give the rms pressure of the sound signal.
		When other methods for characterizing the pressure of the sound wave, such as peak pressure or peak-to-peak pressure, are used, the result is not the relative intensity of the signal, but the relative pressure.
	www.dosits.org /science/adv/sig-levels.htm (1198 words)

	Section 8 Chapter 26 Cardiovascular Monitoring
		The diastolic pressure in the periphery is usually close to the mean pressure distally, which is almost identical to the mean aortic root pressure.
		The cuff is inflated to a pressure that is sufficient to eliminate flow in the underlying artery (e.g., as determined by obliteration of a distal palpable pulse), then gradually deflated while one listens with a stethoscope over the artery at the distal edge of the cuff.
		Pressure in a cuff around the finger is regulated to maintain a constant blood volume in the finger; the pressure waveform required to accomplish this reflects the finger arterial pressure waveform.
	www.acssurgery.com /acsonline/chapters/ch0826.htm (10742 words)

	Biology 2402 Lecture Notes - Water and Mineral Transport
		Root pressure can move water over short distances but does not account for water movement to the top of tall trees.
		Although root pressure plays a role in the transport of water in the xylem in some plants and in some seasons, it does not account for the majority of water transport.
		So although root pressure may play a significant role in water transport in certain species or at certain times, most plants meet their needs by transpiration-pull.
	www.ualr.edu /botany/xylem.html (2542 words)

	Botany online: Growth - Differentiation - Translocation - Ions - Assimilates - Effectors
		The root pressure works especially efficient at night but efficiency decreases during the day since the root pressure becomes much smaller than the rate of transpiration.
		The active transport causes an osmotic pressure within the sieve tube elements that is about twice as high as that of the surrounding cells of the vascular bundle's sheath.
		The drop in the osmotic pressure that becomes lower than that of the xylem leads to an efflux of water and consequently to a decrease of the turgor pressure within the sieve elements of the sink.
	www.biologie.uni-hamburg.de /b-online/e28/28d.htm (1060 words)

	Water Potential including biologically relevant properties of water
		A solution under pressure may have a negative or a positive water potential, depending on the magnitude of the pressure (how far it differs from the reference state of one atmosphere) and the solute content, this last which can be calculated from the van't Hoff equation.
		Study the 3-D aspects of the root, and recall that there is an "inner skin" that forms a tube around the vascular tissue, wherein lies the xylem, which is in apoplastic continuity with the remainder of the plant.
		Pressure is applied, which squeezes the shoot until the tracheary-water column is driven to the cut surface.
	www.bio.fsu.edu /courses/bot-4503/water-potential.htm (9327 words)

	Water movement through a plant
		We know from a very early age that plants obtain water through their roots, though it is not perhaps until our school biology lessons that we learn of the important role that water plays in the process of photosynthesis.
		Just behind the growing tip of a young root is the piliferous region, made up of hundreds of projections of the epidermal tissue, the root hairs.
		Root hairs can be seen very clearly in newly germinated seeds, such as the radish (Raphanus sativus) shown here in the photograph.
	www.microscopy-uk.org.uk /mag/artmar00/watermvt.html (276 words)

	Existing Duct Sizing Methods
		At this time, the pressure loss in junctions can be ignored; a constant pressure loss can be assumed for any junction, or the same cross sections can be used in branches as in trunk ducts.
		This pressure is called the "root pressure." At this step the root pressure is the same as the fan pressure.
		This pressure loss should be larger than the initial pressure loss per unit length assumed for the main critical path in Step 2.
	ateam.lbl.gov /Design-Guide/DGHtm/existingductsizingmethods.htm (1065 words)

	Chapter 26: Nutrition and Transport in Plants (Site not responding. Last check: 2007-10-12)
		Root pressure (primarily at night) tends to push xylem sap upward in plant.
		Root pressure is not a sufficient mechanism for water to rise to the tops of trees.
		Pressure exists from leaves to roots; at roots, sucrose is transported out and water follows.
	www.sirinet.net /~jgjohnso/apbio26.html (2274 words)

	Root pressure - Wikipedia, the free encyclopedia
		When transpiration is high, xylem sap is usually under tension, rather than under pressure, due to transpirational pull.
		If a pressure gauge is attached to the cut stem, the root pressure can be measured.
		Without transpiration to carry the ions up the stem, they accumulate in the root xylem and lower the water potential.
	en.wikipedia.org /wiki/Root_pressure (772 words)

	[No title]
		Roots have many solutes dissolved in their cells, which lowers their water potential in relation to the soil in which they grow.
		Unless the soil is extremely dry, roots have a lower water potential (very negative) than the soil and water tends to move by osmosis from the soil into the roots.
		This theory postulates that sugar moves in the phloem by means of a pressure gradient that exists between the source, where sugar is loaded into the sieve tube members, and the sink, where sugar is removed from the phloem.
	www.cbu.edu /~esalgado/BIOL112/Campbell/ch36.doc (2597 words)

	Root pressure and specific conductivity in temperate lianas: exotic Celastrus orbiculatus (Celastraceae) vs. native ...
		Root pressure and specific conductivity in temperate lianas: exotic Celastrus orbiculatus (Celastraceae) vs. native Vitis riparia (Vitaceae) -- Tibbetts and Ewers 87 (9): 1272 -- American Journal of Botany
		Root pressure and specific conductivity in temperate lianas: exotic Celastrus orbiculatus (Celastraceae) vs. native Vitis riparia (Vitaceae)
		that root pressure is not a prerequisite for weedy proliferation
	www.amjbot.org /cgi/content/full/87/9/1272 (3312 words)

	Transpiration (Site not responding. Last check: 2007-10-12)
		As you can see from this sketch, a gradient of ψs is maintained across the root by delivery of sugar down from the leaves, diffusion out into the cells, and either use or storage of sugar in the form of osmotically almost-inert polysaccharide.
		This gradient is essential for the survival of the root.
		To be honest, the influx of water into roots is not uniform along the length of a root.
	plantphys.info /Plant_Physiology/transpiralec.html (2421 words)

	Dissection of the aorta: a new approach -- Mikich 89 (1): 6 -- Heart
		pressure is 90 mm Hg, and the length of the aorta is 45 cm,
		Forces from blood pressure acting on the flap from the false channel and the true channel are equal and cancel each other, and therefore they are not shown.
		Fp, forces from blood pressure in the aorta; Ff, forces with which the flap pulls the aortic wall.
	heart.bmj.com /cgi/content/full/89/1/6 (1977 words)

	Guttation - Wikipedia, the free encyclopedia
		When there is a high soil moisture level, water will enter plant roots at night because the water potential of the roots is lower than in the soil solution.
		The root pressure forces some water to exude through special leaf tip or edge structures, hydathodes, forming drops.
		Root pressure provides the impetus for this flow, rather than transpirational pull.
	en.wikipedia.org /wiki/Guttation (203 words)

	Direct Measurement of Xylem Pressure in Leaves of Intact Maize Plants. A Test of the Cohesion-Tension Theory Taking ...
		be augmented by a hydrodynamic pressure gradient (dP
		Pressures at which a fracture of the liquid phase occurred were recorded.
		Pressure was a function of the temperature of the sealed microcapillary.
	www.plantphysiol.org /cgi/content/full/121/4/1191 (8222 words)

	root mean square definition - Dictionary - MSN Encarta
		root mean square definition - Dictionary - MSN Encarta
		square root of average: the square root of the mean of the squares of a set of numbers.
		Sometimes the root mean square is a more useful measure of central tendency than the mean or the median.
	encarta.msn.com /dictionary_1861706024/root_mean_square.html (94 words)

	Rapid accumulation of hydrogen peroxide in cucumber roots due to exposure to low temperature appears to mediate ...
		in root tissue by the oxidation of cerium (III) chloride.
		Once stable, root pressure developed at 25 °C, the temperature of the solution bathing the root system was gradually decreased to 8 °C for about 30 min.
		The excised root (n=12) was placed in a chamber and, once a stationary P was obtained after puncturing the cell, the nutrient solution, with different temperatures, was circulated.
	jxb.oxfordjournals.org /cgi/content/full/55/403/1733 (4182 words)

	Chiropractic Research :: Sito Chiropractic
		It is worth noting that Dr. Suh, the first American college professor willing to stick his neck out for chiropractic research, grew up in Korea, where he had not been subjected to the same life-long anti-chiropractic bias as his American colleagues.
		In undertaking this research, he had to withstand intense pressure from powerful forces within the American medical and academic establishments.
		The AMA and cohorts condemned chiropractic for lack of scientific underpinning, while at the same time doing everything in their considerable power to prevent chiropractors from ever obtaining the funding and university connections necessary for the development of such a research base.
	www.sitochiropractic.com /nrp.html (360 words)

	Validation of Nasal Pressure for the Identification of Apneas/Hypopneas during Sleep -- Heitman et al. 166 (3): 386 -- ...
		nasal pressure, and 0.47 and 0.76 for respiratory inductance
		Nasal pressure was measured with respect to mask pressure (E).
		Bland and Altman plots of difference in pressure against mean pressure for the standard laboratory and ambulatory transducers.
	ajrccm.atsjournals.org /cgi/content/full/166/3/386 (3949 words)

	CHAPTER 26, NUTRITION AND TRANSPORT IN PLANTS (Site not responding. Last check: 2007-10-12)
		The point at which water present in the soil is not available to roots because it is too tightly held by
		c) Pressure is created in the phloem by the buildup of water and sugar.
		c) Root pressure is a significant force in driving water up a stem.
	www.sirinet.net /~jgjohnso/apbio26quiz.html (1679 words)

	post root canal pressure/pain - Dentistry.com Message Board
		posted 09-22-2006 02:23 AM I have had many root canals, and have had mild pain that was gone in a few days with all.
		I just recently had a root canal done, and since have gone back once because of the severe pain.
		The dentist thought he may have missed a root, and took extra xrays, and preped the tooth for a crown saying that he could see if he missed a root easier that way.
	www.dentistry.com /ubb/Forum15/HTML/000751.html (213 words)

	Leg Cramps and Nerve Root Pressure - DrDonnica.com - The First Name in Women's Health
		You've described a syndrome called nerve root pressure, which probably has its origins in some sort of back strain, especially if the pain extends below the knee.
		(It could be "sciatica" if the sciatic nerves are affected, but there are many other nerve root possibilities.) With nerve root pressure, the pain is generally worsened by sitting, prolonged standing, forward bending, coughing, sneezing, lifting or straining (as in a bowel movement).
		The pain may be temporarily relieved by walking, lying down, and extending (straightening) the spine.
	www.drdonnica.com /display.asp?article=8774 (382 words)

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