Sentences with phrase «hdyroxide ion concentrations»

This allowed them to track changes in calcium ion concentrations in the cells around wounds in living tissue (as opposed to the cell cultures used in many previous wound response studies) and to do so with an unprecedented, millisecond precision.

When elevating calcium ion concentration directly at the presynaptic terminal with the use of caged calcium, cleavage of SNAP - 25 by botulinum toxin A (BoNT / A) produced a strong reduction in the calcium sensitivity for release, whereas cleavage of syntaxin using BoNT / C1 and synaptobrevin using tetanus toxin (TeNT) produced an all - or - nothing block without changing the kinetics of remaining vesicles.

Further experiments revealed that injured cells initiate a wave of elevated calcium ion concentration that travels through the brain, and that the microglia only begin migrating when the wave reaches them.

Excess carbon dioxide enters the ocean, reacts with water, decreases ocean pH and lowers carbonate ion concentrations, making waters more corrosive to marine species that need carbonate ions and dissolved calcium to build and maintain healthy shells and skeletons.

Continuous measurement and imaging of the intracellular free calcium ion concentration -LRB-[Ca2 +] i) of mitotic and interphase PtK1 cells was accomplished with the new fluorescent Ca2 + indicator fura - 2.

However, Bressloff explains, a calcium - ion concentration shift happens too quickly to create a memory — because of the fast equilibration, it will be resolved within a minute.

The uptake of fossil fuel carbon dioxide (CO2) by the ocean increases seawater acidity and causes a decline in carbonate ion concentrations.

Known as gustducin, the protein triggers a cascade of chemical reactions that lead to changes in ion concentrations within the cell.

«Periods of very intense North Atlantic circulation and higher Northern Hemisphere temperatures increased the preservation of microfossils in the sediment cores, whereas those with slower circulation, when the study site was primarily influenced from the south, were linked with decreased carbonate ion concentrations at our core site which led to partial dissolution,» said co-author Dr Luke Skinner, also from Cambridge's Department of Earth Sciences.

Since reef - building corals need carbonate to build their skeletons, decreasing carbonate ion concentrations will likely lead to weaker, more brittle coral skeletons and slower coral growth rates.

Atmospheric CO2 is absorbed by the ocean and results in a decrease in carbonate ion concentration, making carbonate ions unavailable to corals and other marine calcifiers.

Changes in the carbonate ion concentration in seawater can affect the saturation state (and hence biological availability) of several types of calcium carbonate (e.g., calcite, aragonite, or high - magnesian calcite.

In turn, this could indicate that the carbonate ion concentration of the (western) Pacific at depths shallower than the sill to the SCS (ca. 2,400 m) has not changed appreciably between the last glacial period and the present interglacial.

This task can be achieved by providing proxy - based reconstructions of seawater pH, carbonate ion concentrations, and pCO2 along with the response of the marine calcifiers during key intervals of the Late Quaternary.

(from 370 to 470 ppm) would decrease carbonate ion concentration by 40 % more than would have been the case if carbon dioxide concentrations were raised from the pre-industrial 280 to 380 ppm.

Places like waterfalls and beaches where negative ions are naturally produced can have a negative ion concentration of up to 10,000 negative ions per cubic centimeter whereas busy cities can have negative ion levels as low as 100 ions per cubic centimeter.

The rationale is simple: Increases in potassium ion concentration stimulate the secretion of insulin (Desirable in terms of treatment objectives).

Learners will answer questions about: • Acid - base definitions • Hydrogen ions and acidity • pH calculations • hydrogen ion and hdyroxide ion concentrations • acid and base strength • acid dissociation constant • neutralisation reactions • salts in solution • titration calculations This resource is meant to be used by teachers in the US.

pH is an indicator of acidity by measuring the hydrogen ion concentration.

«Addition of carbon dioxide to the ocean reduces the carbonate ion concentration and thereby reduces the solubility of carbon dioxide in seawater.

(from 370 to 470 ppm) would decrease carbonate ion concentration by 40 % more than would have been the case if carbon dioxide concentrations were raised from the pre-industrial 280 to 380 ppm.

If the surface ocean pCO2 concentrations continue to increase in proportion with the atmospheric CO2 increase, a doubling of atmospheric CO2 from preindustrial levels will result in a 30 % decrease in carbonate ion concentration and a 60 % increase in hydrogen ion concentration.

If we raise the CO2 concentration in the atmosphere to Cretaceous levels and hold it there for 10,000 years or so, the CaCO3 cycle in the ocean will restore the carbonate ion concentration back toward CaCO3 saturation.

If the surface ocean PCO2 concentrations continue to increase in proportion with the atmospheric CO2 increase, a doubling of atmospheric CO2 from preindustrial levels will result in a 30 % decrease in carbonate ion concentration and a 60 % increase in hydrogen ion concentration.

Natural seasonal variations in carbonate ion concentrations could either hasten or dampen the future onset of this undersaturation of calcium carbonate.

Acidity is a measure of hydrgen ion concentration.

From preindustrial levels, contemporary surface ocean pH is estimated to have dropped on average from 8.2 to 8.1, or by about 0.1 pH units (a 26 % increase in hydrogen ion concentration), and further decreases of 0.22 to 0.35 pH units are projected over this century unless carbon dioxide emissions are significantly reduced (Orr et al., 2005; Bopp et al., 2013).

Many organisms require supersaturated conditions to form sufficient calcium carbonate shells or skeletons, and biological calcification rates tend to decrease in response to lower carbonate ion concentrations, even when the ambient seawater is still supersaturated.

In that respect, what I find more interesting is the lack of (un) certainty discussion in the text I quoted, although describing «a 26 % increase in hydrogen ion concentration» as «almost 30 % more acidic» is telling.

From preindustrial levels, contemporary surface ocean pH is estimated to have dropped on average from 8.2 to 8.1, or by about 0.1 pH units (a 26 % increase in hydrogen ion concentration), and further decreases of 0.22 to 0.35 pH units are projected over this century unless carbon dioxide emissions are significantly reduced.

This second reaction is important because reduced seawater carbonate ion concentrations decrease the saturation levels of calcium carbonate (CaCO3), a hard mineral used by many marine microbes, plants and animals to form shells and skeletons.

and as Judith notes, adding CO2 has thus far increased the hydrogen ion concentration in the oceans by 26 % thus rendering them more acidic.

Local researchers and fishermen have also been raising the alarm about ocean acidification, which is when carbon dioxide goes into the ocean and creates corrosive carbonic acid, reducing the pH and the carbonate ion concentration in the sea water.

My guess is that the oceans are about pH 7.6 (+ / - 0.2 pH) so this means that the hydrogen ion concentration has to increase by a factor of 4 before the oceans become acidic.

Holds that for most open - ocean surface waters, aragonite undersaturation occurs when carbonate ion concentrations drop below approximately 66 µmol kg - 1

Ion concentration is determined by adding the number of ions counted at the molecular ion's mass - to - charge ratio to the number of air molecules in the reaction chamber, which can be identified according to the pressure levels in the reaction chamber.

Recently, laboratory experiments with live foraminifera have demonstrated that the photosynthetic activity of algal symbionts and the carbonate ion concentration -LRB-[CO32 --RSB--RRB- of seawater also affect shell d18O values.

Finds that for calcite, undersaturation occurs when carbonate ion concentration drops below 42 µmol kg - 1

If that is too hard for you to comprehend, ask your doctor to play around with your bloodstream's elemental ion concentrations and see what happens.

The decreases in calcification and PIC occur simultaneously with decreases in the observed carbonate ion concentration, suggesting a possible link between acidification and decreasing calcification in this vulnerable region.

This acidification occurs in a region with a naturally low carbonate ion concentration, and studies suggest that the surface of the Southern Ocean will become undersaturated with respect to calcium carbonate minerals aragonite and calcite by the end of the century.

If carbonate ion concentrations are lower, calcium carbonate minerals are more likely to dissolve.

Effect of carbonate ion concentration and irradiance on calcification in planktonic foraminifera

Past hypotheses arguing calcification was dependent on carbonate ion concentration, or aragonite and calcite saturation levels, were most likely misled by the fact that higher carbonate ion concentrations are a daily «side effect» of photosynthesis.

The pH scale is logarithmic, so a change of 1 unit corresponds to a 10-fold change in hydrogen ion concentration.

Here is another post I did on this topic http://chriscolose.wordpress.com/2007/12/22/corals-in-peril/ Increasing H3O ^ + obviously does raise the acidity, as the anonymous poster mentioned... the slight change in pH can have a remarkable effect on the change in Hydrogen ion concentration.

This study projects contrasting seasonal changes of the hydrogen ion concentration, pH, and carbonate saturation state, which will exacerbate and ameliorate ocean acidification impacts.

The ion concentration in SKY was estimated based on the energy provided by the electron beam, and the sulphuric acid concentration was estimated based on production and loss rates.

The decrease in surface carbonate ion concentrations is found to be largest at low and mid-latitudes, although undersaturation is projected to occur at high southern latitudes first (Figure 10.24).

The CLOUD experiment measured the sulphuric acid vapour concentration using a Chemical Ion Mass Spectrometer, the ion concentration using a Gerdien counter, and the formation rate of particles at different sizes were measured using multiple instruments described in the Methods section of Kirkby et al. (2011), with 50 % cutoff diameters between 1.3 nm and 12 nm.