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Q is for Quaternary #AtoZChallenge

Q is for Quaternary

The Quaternary is a period of geologic time which includes the last approximately 2.6 million years of Earth’s history, including the present.

The advantage of working with materials from the Quaternary Period is that materials are so new that organic molecules are often preserved. With techniques of organic chemistry, it is possible to find fossilized leaves and isolate certain molecules, such as leaf waxes. Continue reading “Q is for Quaternary #AtoZChallenge”

N is for Nitrogen #AtoZChallenge

N is for Nitrogen

Nitrogen is the most abundant gas in the Earth’s atmosphere. It is also an important component of the amino acids that make up proteins in the bodies of living organisms.

Isotopes of nitrogen fractionate according to trophic level, that is, where the organism lies on the food chain (more properly, the food web). This is the origin of the common saying in isotope geochemistry, “You are what you eat, plus a few permil.” For nitrogen, on average a consumer’s δ15N is 3‰ more positive than the organism that is being eaten (whether it be a plant or another animal).

This relationship of nitrogen isotopes in proteins can be used to determine predator-prey relationships between extinct animals, presuming that proteins are preserved.

M is for Magnet #AtoZChallenge

M is for Magnet

A common feature of mass spectrometers is a magnet. A strong magnetic field is necessary to separate the molecules of slightly different mass for measurement.

Not all mass spectrometers work in the exact same way, but all use powerful magnets to select atoms and molecules of specific masses so that it’s possible to measure the amount of the different isotopes of specific elements. The configuration of these magnets differs depending on the isotopes being measured.

Mass spectrometers such as the DeltaPlus XP here at SIREAL have a single magnet that splits a beam of ionized gas into two or three beams of different masses that are measured simultaneously. This makes it possible to calculate the ratios necessary for the delta values (see D is for delta).

L is for LIMS #AtoZChallenge

L is for LIMS

LIMS is an acronym that means “Laboratory Inventory Management System.” Because of the amount of data that laboratories such as ours must keep track of, using LIMS is necessary.

At SIREAL, we use LIMS for light stable isotopes that was developed at the Reston Stable Isotope Laboratory, part of the United States Geological Survey.

LIMS for light stable isotopes does more than just organize and store your data, it also contains all the necessary algorithms and does the necessary calculations to convert raw data from the mass spectrometer into usable isotopic results that can be compared among laboratories internationally.

K is for Cretaceous #AtoZChallenge

K is for Cretaceous

Cretaceous starts with a ‘C,’ so why is it K for Cretaceous? All the divisions of the Earth’s geological time scale have one- or two-letter designations, kind of like all the elements of the periodic table have a symbol (like C for carbon or Au for gold). The abbreviation for Cretaceous is K, from the German for chalk (kreide) and also because ‘C’ is also already used for Carboniferous.

For today’s installment, we’ll look a paper that utilizes stable oxygen isotopes from the teeth of a dinosaur to determine how fast the teeth grown.

Suarez, You, Suarez, Li, and Treischmann, 2017, Stable isotopes reveal rapid enamel elongation (amelogenesis) rates for the early Cretaceous iguanodontial dinosaur Lanzhousaruus magnidens, Nature Scientific Reports, v. 7: 15319 | DOI:10.1038/s41598-017-15653-6

Iguanodontians were herbivorous dinosaurs with tightly packed teeth optimized for chewing vegetation. These dinosaurs replaced their teeth continuously though life so that their chewing mechanism was always ready to go. Continue reading “K is for Cretaceous #AtoZChallenge”