Isotope

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Synopsis: Chemistry & chemical compounds: Chemical compounds: Isotope:

Another tool, isotope ratio analysis, can determine subtle differences between food whether a fish was farmed or wild, for example,

Carbon isotope dating revealed the cave had been used in the Mesolithic period between 9210 and 8340 B c

Separately the researchers also analyzed carbon and nitrogen isotopes or variants of the same elements with different molecular weights.

Because different foods contain different ratios of heavy and light isotopes the team was able to pinpoint the diets of the ancient people.

Isotope analysis also revealed the latter group subsisted on a diet of mainly freshwater fish while the farmers ate more domesticated animals.

Cesium isotopes have longer half-lives (cesium-137 has a half-life of 30 years) and are a concern for years after their release into the environment.

what the animal was eating by adding data from stable carbon isotopes. Potential uses Samuel Wasser a conservation biologist at the University of Washington who did not participate in the study said the new study is a very important development

The new results published in several studies today (June 3) in the journal Proceedings of the National Academy of Sciences (PNAS) were found by analyzing the fraction of different carbon isotopes or atoms of the same chemical with different molecular weights

The 10 Biggest Mysteries of the First Humans Diet insight Because plants using different methods of photosynthesis to grow absorb different amounts of carbon isotopes the ratio of those isotopes in dental enamel can reveal insights

For instance so called C3 plants absorb more of the heavy isotope carbon-13 into tissue than do C4 or CAM plants.

To analyze what the ancient human ancestors were eating the team analyzed the fraction of different carbon isotopes in teeth from every early human fossil that could be sampled:

Now thanks to stable-isotope analyses we no longer have to guess and the broad pattern of early hominin dietary evolution is established.

 Based on levels of radioactive isotopes or atoms of the same elements with different molecular weights the team estimated that the site was occupied almost continuously between 9800 and 12000 years ago.

There are 17 known isotopes of potassium. Ordinary potassium is composed of three isotopes. One 40â°K (0. 0118 percent) is radioactive with a half-life of 1. 28 x 109â years.

Despite its radioactivity potassium presents no significant hazard when handled. Sources of Potassium Potassium is the seventh most abundant metal in the world.

He measured the ratio of carbon isotopes (atoms of the same element with a different number of neutrons)

which changes as the radioactive carbon-14 isotope breaks down over time while the stable carbon-12 does not.

A laser isotope ratio-meter was developed to search for methane gas on Mars according to Wired UK.

Honey is an ideal application for the laser isotope ratio-meter because it's an expensive product to buy

but you can create a counterfeit product that looks very similar using sugar instead of bees David Bell director of Protium (manufacturer of the isotope ratio-meter) told Wired UK.

By looking at the levels of this carbon isotope known as carbon-14 in elephant tusks and ivory researchers can find out how old they are.

Isotopes are versions of elements that have differing numbers of neutrons in their nuclei. Knowing the age of elephant tusks is important

and fellow researchers looked for signatures of corn in the carbon isotopes (carbon atoms with different molecular weights) of 185 soil cores.

Roman locavores To determine diets from the Roman skeletons the researchers analyzed the bones for isotopes of carbon and nitrogen.

Isotopes are atoms of an element with different numbers of neutrons and are incorporated into the body from food.

Such isotopes of carbon can tell researchers which types of plants people consumed. Grasses such as wheat and barley are called C3 plants;

The differences in photosynthesis create different ratios of carbon isotopes preserved in the bones of the people who ate the plants.

Nitrogen isotopes on the other hand give insight into the kinds of protein sources people ate. We found that people were eating very different things Killgrove said.

One man whose isotope ratios showed him to be a major millet consumer was likely an immigrant later research revealed.

Carbon isotopes (atoms of the same element that have revealed different molecular weights that the trees were about 52000 years old.

and the change in isotopes in the early 1980s the research went into a different direction...

sulfur isotopes (variations of an element with a different number of neutrons) pointed to pollution

and carbon isotopes showed that the trees'stomata (the pores that are opened and closed to regulate the exchange of carbon dioxide

Meanwhile sulfur isotopes in the wood of tree rings approached levels not seen since the preindustrial age.

The team then dated the structure using levels of radioactivity in minerals and the ratio of carbon isotopes or molecules of carbon with different numbers of neutrons from charcoal and grains of sand.

Research on stable isotope ratios has seen already a number of interesting results. In one case understanding the stable isotope ratios of hair led to the identification of a murder victim by determining her travel history.

It turns out that stable isotope ratios of oxygen and hydrogen in water vary with geography on a continental scale

and so because the stable isotope ratios in drinking water get incorporated into hair a record of travel history is revealed by looking at the isotope composition of scalp hair.

Another example of the usefulness of stable isotope ratios can be found in the tropics where woody plants and grasses

which use different types of photosynthesis have very different carbon isotope ratios. We have used stable isotopes to quantify African elephant diet over time as it relates to rainfall history

which is useful information for elephant conservation. Typically after rainfall grasses become more abundant and constitute a greater portion of an elephant's diet.

Using carbon isotopes in hair we can see exactly how much grass these animals are eating

and how their diet changes with changes in rainfall. Similarly we have used carbon isotopes in fossil soils to determine the fraction of woody cover sites that bear hominin fossils a problem that has implications for the history of our species

. Because woody plants and grasses have very different carbon isotope ratios there is a strong relationship between carbon isotope ratios of soil

and fraction of woody cover. In other research my work on acetaminophen overdose will hopefully have a direct impact in how medical doctors view acetaminophen overdose patients.

History's Most Mysterious Extinctions Carbon signatures The scientists focused on isotopes of carbon in plant waxes found in ancient soils and sediments.

Carbon isotopes differ in how many neutrons they possess in their atomic nuclei carbon-12 has six neutrons

and mostly practice a kind of photosynthesis known as C4 which uses both carbon-12 and the heavier carbon-13 isotope.

By analyzing the ratios of these different carbon isotopes within plant waxes the researchers could infer what plants dominated the region at different times in the past.

The sixth-lightest element on the periodic table carbon exists in nature as two stable isotopes:

Isotopes of the same element behave the same in chemical reactions but have slightly different atomic masses with the carbon-13 being slightly heavier than the carbon-12.

The common C3 plants take in less of the heavier isotope carbon-13 while the C4 plants take in more.

If you eat a lot of C3 plants the concentration of carbon-13 isotopes in your body will be lower than

They measured carbon-13 to carbon-12 ratios (and also some other isotope ratios) in bone enamel and hair in these remains and compared them to similar measurements performed on pigs that had received controlled diets consisting of different proportions

As pigs have a similar metabolism to humans their carbon isotope ratios could be compared to

or teeth and the isotope ratios in hair of the mummies corresponded to that found in hair of modern European vegetarians confirming that the ancient Egyptians were also mainly vegetarians.

All this makes it a bit surprising that the isotopes should suggest that fish was consumed not widely.

When these rocks are analyzed they are found to contain higher than normal levels of carbon-12 isotopes compared to carbon-13 isotopes

Johnson counted isotopes of beryllium-10 in the rocks to determine their time at the surface.

Isotopes are atoms of the same element with different numbers of neutrons. Rocks On earth's surface are bombarded by cosmic rays from outer space that create beryllium-10 isotopes at a steady rate.

The rate of thinning that we detected from our rock samples is comparable to the contemporary rate detected by satellites Johnson said.

Deuterium is an isotope of hydrogen its atoms each possess a single proton like regular hydrogen

the team analysed the hydrogen isotope ratios of fat residue in pottery shards and found two distinct signatures that seemed to correspond to horse carcass fat and mare's milk.

Wheat and maize have different ratios of these carbon isotopes. After only two weeks, Agashe found, the beetles'diet shifted to almost 30%maize flour.

producing electricity and a range of nuclear isotopes, including plutonium. Iran denies that the reactor has a military purpose.

Isotope shortage: A nuclear reactor in Petten, The netherlands, that supplies radioactive isotopes for use in medical imaging reopened last week after a month's scheduled maintenance partly alleviating a global shortage of the isotopes (see Nature 460,312-313;

2009). ) But the reactor is due to shut down again next March for six months of repairs.

Canada's Chalk River, Ontario, reactor whose closure precipitated the isotope crisis will not reopen until 2010.

Yeakel analysed the ratios of carbon isotopes in the lions'tissues, which should reflect the isotope ratios of their prey.

Browsing animals, such as giraffes and antelopes, have different ratios of carbon isotopes to grazers because their food shrubs and trees versus grasses carries out different types of photosynthesis. The team characterized the humans'isotope ratios by taking advantage of a fluke of history,

says team leader Nathaniel Dominy, also at the University of California, Santa cruz. In the early twentieth century,

an archaeologist took more than 100 Taita skulls from Kenyan shrines and shipped them to England.

and found that the Taita's ratio of nitrogen isotopes was distinct from the herbivores.

which prey combinations were most likely to produce the lions'isotope ratios. The results show that for most of their lives,

Extrapolating from their isotope ratios, the authors conclude that, over the 9 month period, the lions probably consumed around 10.5 and 24. 2 humans, respectively,

The different prey possibilities have similar isotope ratios, he says. As a result, a wide range of proportions of available prey items could account for the lions'isotope ratios,

including many or no people, even during the period before they became maneaters. Yeakel acknowledges that there are many possible combinations the model shows that humans could have made up 4-56%of the dominant maneater's diet

Nature Newsthe burning of fossil fuels such as coal and oil releases carbon dioxide that alters the balance of carbon isotopes naturally found in the environment an effect that is now being found in food,

Modern methods for tracking the origins of processed foods use isotopes atoms of the same element that have different numbers of neutrons.

Of the most common naturally occurring isotopes of carbon carbon-12, with six neutrons, and carbon-13, with seven the heavier carbon-13 isotope is rarer.

In many plants, 108 out of 10,000 carbon atoms are carbon-13. However in plants such as sugar cane and maize (corn),

the carbon isotope ratio of the final product will be skewed. As part of an undergraduate project intended to show how isotope analysis works,

geochemist William Peck at Colgate university in Hamilton, New york, got his students to analyse maple syrup from different parts of the northeastern United states. Our intent was really just to see

if isotope values varied by geography or if anyone was putting in sweeteners, says Peck.

All of the isotope values that the class collected were much the same, but when the group compared their values to isotope values of maple syrup in papers from the late 1970s and early 1980s,

they noted that there were significant differences. Their analysis revealed that the relative amount of carbon-13 in maple syrup seemed to have gone down since the 1970s.

if it was possible that baseline isotope ratios might be shifting because of environmental changes. To work this out Peck

if the mould might change the isotope ratio of the syrup, recalls Peck. Fortunately, it did not.

and Food Chemistry1 that maple syrup isotope ratios have shifted over the years. Samples of 1970s syrup had 108.7 carbon-13 isotopes per 10,000 carbon atoms

whereas the 2006 average was 108.5 carbon-13 isotopes per 10,000 carbon atoms. So syrup carbon-13 values are approaching the average 108 value that maple trees

and most plants should have, explains Peck. The reason, he suggests, is released that carbon from the burning of oil or coal,

is shifting environmental carbon isotope ratios accordingly. Atmospheric data show that isotope ratio changes correlate directly with the changes in the maple syrup isotopes over the course of the 36 years studied

Peck says. We've known that atmospheric carbon isotope values were changing, but nobody was applying this to food science,

says geochemist John Valley at the University of Wisconsin-Madison. Clearly, food-monitoring studies need to start taking atmospheric isotope data into account.

The findings raise the possibility that producers of foods that are monitored for carbon isotope ratios might be able to add cheap sweeteners without being caught.

Yet Peck doubts this is the case. The producers that could cheat have not had the necessary information do so effectively,

Isotope analysis of human tissue is being considered in some countries to help determine where immigrants have come from.

If we are making serious decisions about peoples'lives with isotope analysis, we must remember that there are numerous effects that determine the final values,

As for whether isotope ratios change the taste of maple syrup, for the moment, that remains a mystery.

Nature Newsoxygen isotopes in clamshells may provide the most detailed record yet of global climate change,

says William Patterson, an isotope chemist at the University of Saskatchewan in Saskatoon, Canada, and lead author of the study1.

and the levels of different oxygen isotopes in their shells vary with the temperature of the water in

The colder the water, the higher the proportion of the heavy oxygen isotope oxygen-18.

isotope ratios in each of these shells provided a two-to-nine-year window onto the environmental conditions in

which measured the isotopes in each layer. From those, the scientists could calculate the conditions under which each layer formed.

They base this interpretation on an analysis of stable carbon isotopes in preserved soil or'palaeosol',at the site;

oxygen and carbon isotopes in the enamel of mammalian teeth; the small-mammal fossils present;

One technique relies on the radioactive isotope carbon-14, which occurs in trace amounts in atmospheric carbon dioxide.

This isotope is released taken up and by plants, but fossil fuels have no carbon-14 because it has a relatively short half-life

where the land is unlikely to be contaminated with à Â-particle-emitting isotopes potentially the most damaging if inhaled.

Dahl's team looked at the concentration of molybdenum and the ratios of its isotopes atoms of the same element with different numbers of neutrons and different masses in oceanic rocks for clues to the concentration of oxygen in the seas

In oxygenated water, the lighter of the two main molybdenum isotopes 95mo and 98mo is absorbed into the seabed

leaving the heavier isotope in solution. Sea water gets lighter and heavier as a measure of the balance between oxic

Dahl's study uncovered two periods when heavy molybdenum isotopes show up in the shale records

They performed carbon-isotope analyses on soil layers and studied fossilized plant materials to work out how the land was used.

The study takes advantage of the fact that plants preferentially take up the isotope carbon-12,

That number would have to be offset by terrestrial emissions to maintain the atmospheric carbon isotope ratio.

Radioecologists with The french Institute of Radioprotection and Nuclear Safety (ISRN) in Cadarache converted concentrations of radioisotopes measured in the soil and seawater into the actual doses that various groups of wildlife were likely

The french team reckons that about 50 radioisotopes have been released, with iodine-131 and caesium-137 being the most abundant (see'Radiation release will hit marine life').

which organisms absorb radioisotopes, such as a species'cellular characteristics and metabolism. The dose rate (measured in milligrays per day) specifies how much radiation is absorbed per kilogram of organic tissue per day

Their first results, to appear in the Japanese journal Radioisotopes in August, paint a surprisingly optimistic picture.

and potatoes that were planted a few weeks after rains showered the field with radioisotopes from Fukushima.

and could be washed off, suggesting that the plants were not absorbing dangerous levels of radioisotopes directly from the soil.

Despite this good news, the team's data also show that the radioisotopes seem to be stuck firmly to the soil,

This might prevent the radioisotopes from entering groundwater, but suggests that cleaning up the more radioactive public spaces in Fukushima prefecture will not be easy.

arguing that such phyto  remediation would absorb only small amounts of radioisotopes. Chihiro Inoue

and using the relative levels of carbon isotopes to pick out more exactly the origin of those fats in 29 of the samples.

Carbon isotopes from milk fat can also point to the sorts of food the dairy animals ate

Tracing of the radioisotope calcium-45, for example allows sensitive measurements of calcium carbonate uptake in the skeletons of marine organisms,

MÃ lanie Salque, a chemist at the University of Bristol, UK, used gas chromatography and carbon-isotope ratios to analyse molecules preserved in the pores of the ancient clay

ratios of oxygen and nitrogen isotopes in the core show that some 6, 000 Â years after the onset of the Eemian,

That isotope was relatively easy to work with because it is long-lived. Other putatively pear-shaped peers are highly unstable and difficult to handle.

and his colleagues fired a high-energy proton beam at a piece of uranium carbide in the ISOLDE isotope mass separator facility at CERN, Europe's particle-physics laboratory near Geneva, Switzerland."

"A whole cauldron of isotopes is made when you splat protons onto the target, says Butler.

and predicts that the lighter isotopes of radium should be more strongly pear shaped than the heavier ones.

The latest result confirms that radium isotopes should be a good place to look for for electric dipoles,

and that some isotopes of thorium and uranium might be even better.""I believe that this will eventually lead to results of much broader impact than this experiment alone,

the researchers analysed the nitrogen isotopes found in bone collagen, which reflect the main source of protein in the diet.

and geologists from the U s. Kenya and the U k. use mass spectrometry to determine the amount of carbon-14 a rare radioactive isotope of carbon appears in an animal tissue.

By contrast coal-fired power plants release higher quantities of radioactive isotopes directly into the atmosphere than even the oldest nuclear reactors ever did.

and the nuke plants that create those isotopes or the ones that were built specifically for safer power generation

Carbon's key radioactive isotope carbon-14 forms when energetic particles enter Earth's atmosphere

So the formation of radioactive isotopes isn't a steady process? This could cause us to change our assumptions about dating methods.

tree ring studies and sedimentary cores can often be used to identify variations in the atmospheric concentrations of whichever isotope is being used

They were measuring the relative change in the isotope from one year to the next. As a side note that may interest@Bagpipes100:

Carbon isotopes indicate that rodents domestic dogs and pigs from the ancient village were eating millet

Carbon and nitrogen isotopes show that cats were preying on animals that lived on farmed millet probably rodents.

For this purpose they initially marked the pesticide to be examined with the nonradioactive heavy carbon isotope 13c

Isotope data show that they ate these species and the dog may have been derived from a wolf similar to these ancient wolves in the late Pleistocene of Europe.

but a small percentage of oxygen is the heavier O-18 isotope. When seawater evaporates off the ocean to form clouds some drops fall as rain over the ocean

Mayer is recognized an internationally expert in the use of stable isotopes to track contaminants in the environment.

The french-U of C study is the first that tracks using stable isotope fingerprinting the fate of fertilizer N remaining in the soil zone over several decades.

The research team used a stable isotope of nitrogen N-15 as a tracer to track fertilizer nitrogen applied in 1982 to sugar beet and winter wheat crops on a pair of two-metre-square plots

#First long temperature reconstruction for the eastern Mediterranean based on tree ringsfor the first time a long temperature reconstruction on the basis of stable carbon isotopes in tree rings has been achieved for the eastern Mediterranean.

The analysis of carbon isotope ratios (13c/12c) in tree rings aims to close this research gap.

The carbon isotope ratios measured in individual tree rings largely depends on the environmental conditions; thus the varying tree-ring isotope values are good indicators for changes in the environment.

The carbon isotope ratios in the trees from Turkey indicate a temperature sensitivity of the trees during late winter to early spring.

In cold winters the cambium and the leaves are damaged more than usual and the following recovery in spring takes longer.

The researchers analyzed the stable carbon isotopes within each tree ring as a recorder of physiological changes through time.

Nippert's Stable Isotope Mass Spectrometry Laboratory at Kansas State university analyzed the samples. Researchers analyzed tree rings back to the early 1900s when sulfur dioxide deposition throughout the Ohio river Valley began to increase.

However this new research shows that enriched levels of nitrogen-15 a stable isotope abundant in manure have been found in the charred cereal grains

and nitrogen isotope analysis of 124 crop samples of barley wheat lentil and peas totalling around 2500 grains or seeds.

Archaeologists rely on the stable isotope analysis of the skeletal remains to establish a signature which provides information about what people once ate.

The heavier stable isotope of nitrogen-15 found in manure mimics the isotopic effect of a diet rich in meat and milk.

The crop nitrogen isotope analysis suggests that early farmers in Europe used their manure strategically as a resource that was limited by the number of animals they owned

and count when the isotope decays radioactively. In the study the researchers used accelerator mass spectrometry or AMS which requires 1000 times less material for analysis--a big advantage

what prehistoric and modern animals ate over time especially when combined with existing isotope analysis of ratios of carbon-13 to carbon-12 in teeth--data that reveal

and Alpine Research Stable Isotope Laboratory and Radiocarbon Laboratory in Boulder for analyses to determine the carbon's sources

In four new studies of carbon isotopes in fossilized tooth enamel from scores of human ancestors and baboons in Africa from 4 million to 10000 years ago a team of two dozen researchers found a surprise

The isotope method cannot distinguish what parts of grasses and sedges human ancestors ate--leaves stems seeds and-or underground storage organs such as roots or rhizomes.

What You Eatthe new studies analyze carbon isotope results from 173 teeth from 11 species of hominins.

but the new studies include new carbon-isotope results for 104 teeth from 91 individuals of eight hominin species. Those teeth are in African museums

The method of determining ancient creatures'diets from carbon isotope data is less than 20 years old

The powder was placed in a mass spectrometer to learn ratios of carbon isotopes incorporated into tooth enamel via diet.

To take the temperature of the past we rely on indirect evidence like oxygen isotope ratios in the fossil shells of marine organisms

and radon atoms at CERN's Isotope Separator facility ISOLDE The atom beams were accelerated and smashed into targets of nickel cadmium

and Europe where new techniques are being developed to exploit the special properties of radon and radium isotopes.

'By studying the levels of isotopes in the bones we can for example find out where the animals were raised

and wheat were farmed at the site they point to elevated levels of the isotope N15 (nitrogen 15).

Isotopes are different atoms of the same chemical element that have a slightly different mass. Different stars produce different proportions of isotopes.

But the material from which our solar system was fashioned was mixed and homogenized before the solar system formed.

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