Sentences with phrase «chemical evidence»

Rather than ordinary spot - testing approaches, which look for unnatural ratios between biological constituents in a single sample or for direct chemical evidence of known doping agents, the passport allows investigators to see the big picture — any deviations from the rider's test - established norm that might result from doping, even if the specific drug or tactic remains unknown.

They contain chemical evidence for nitrogen fixation by microbes.

The one we worked on is at least 3.02 billion years old, and it shows chemical evidence that weathering took place in an atmosphere with elevated O2 levels.»

Although sheep were domesticated by ≈ 11000 before present (BP)(25) and goats and cows by ≈ 10000 BP (26,27), early direct chemical evidence for dairying dates to 6100 to 5500 BP from residues of dairy fats found on pottery in Britain (28).

Over the last 10,000 years, snow and rain dripped into the depths of Scărișoara, where they froze into thin layers of ice containing chemical evidence of past winter temperature changes.

Curiosity is climbing a layered Martian mountain and finding chemical evidence of how ancient lakes and wet underground environments changed, billions of years ago, in ways that affected their potential favorability for microbial life.

The work traces violence and hardship so intense that they left a vivid record in people's bones: skull fractures indicating a surge of nonfatal and fatal head injuries and chemical evidence suggesting widespread starvation.

«The tug - of - war comes from life pulling in the other direction, and we can see chemical evidence of that.

That vinicultural honor still belongs to the Yellow Valley of China, where researchers uncovered chemical evidence of grape wine — fortified with fruit wine, rice beer, and honey mead — dating back to 7000 B.C.E.

In May, his team identified the first chemical evidence for ancient Egyptian medicines in vessels from the 5,000 - year - old tomb of Pharaoh Scorpion I — and they were spiked with grape wine imported from the Jordan River valley.

The available chemical evidence points to the action of silicates in rocks: The compounds somehow turn carbon into bicarbonate and pull it out of the biosphere.

«Yang and his team are the first to provide detailed chemical evidence of bacterial degradation» of polyethylene, says Kenneth H. Nealson, an environmental microbiologist at the University of Southern California.

Biologists have arrived at educated guesses and rough answers from indirect chemical evidence.

The ambiguity of chemical evidence leaves geologists hungry for a well - defined, and ideally photogenic, fossil or two.

Even the oldest samples, 3.2 billion years old — three - quarters of the way back to the birth of the planet — showed chemical evidence that life was pulling nitrogen out of the air.

Now, an international team of researchers has found chemical evidence of melanosome preservation in fossilized dinosaur feathers, using evidence from a specimen of Anchiornis huxleyi.

Looking forward, the researchers are now hoping to examine other Ediacaran sediments from around the globe to verify the rapid reversals» signal, along with hunting for biological or chemical evidence for high doses of UV radiation in the fossil record.

To date, most missions to Mars have been trained on its surface, seeking geological and chemical evidence of habitability.

From e1 (physical and chemical evidence) the prediction e2 (the explosion) was warranted to the scientist's mind because of the mediation of nuclear theory.

The chemical evidence for hydrated minerals at Gale Crater and elsewhere means water is definitely the top contender — although one team member likes to joke that, for all we know, the liquid could have been beer.

Scientific rifts The new data fit in well with what many researchers have come to think about the shifting dynamics of the Earth's mid-history based on other rock and chemical evidence: there was a major shift some 3 billion years ago.

That chemical evidence is compelling, but circumstantial.

One way to look for such clues is to search for chemical evidence, particularly in light passing through the atmospheres of the planets, Rein says.

«Portable NIST kit can recover traces of chemical evidence.»

Next, in search of chemical evidence to back up their idea, the researchers took sand samples from several beaches in Mauritius, another African island nation located about 1700 kilometers southeast of the Seychelles.

The study examines anatomical, paleoenvironmental and chemical evidence, as well as the feeding behavior of living animals.

The chemical evidence, much of it based on degradation, thermochemical, and spectroscopic studies, supported the β - lactam structure, but Robinson's prominence and persuasiveness kept the controversy going.

We know the increase is due to human activities like burning fossil fuels because we can analyze the chemical evidence for that.

The last main category of evidence in a DUI case is one that can be very complicated — chemical evidence.