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LOS ANGELES Cheap Giacomo Bonaventura Jersey , Sept. 11 (Xinhua) -- An international research team led by Chinese astronomers revealed an evidence of dynamical dark energy.
The discovery, recently published on Nature Astronomy, with a News & Views article written by a world expert on cosmology, found that the nature of dark energy may not be the cosmological constant introduced by Albert Einstein 100 years ago, which is crucial for the study of dark energy.
The new study was supported by the National Natural Science Foundation of China (NSFC), Chinese Academy of Sciences, and a Royal Society Newton Advanced Fellowship.
Revealing the nature of dark energy is one of key goals of modern sciences. The physical property of dark energy is represented by its Equation of State (EoS) Cheap Gerard Deulofeu Jersey , which is the ratio of pressure and energy density of dark energy.
In the traditional Lambda-Cold Dark Matter (LCDM) model, dark energy is essentially the cosmological constant, i.e., the vacuum energy, with a constant EoS of -1. In this model, dark energy has no dynamical features.
In 2016, a team within the SDSS-III (BOSS) collaboration led by Prof. Gong-Bo Zhao of National Astronomical Observatories of China (NAOC) performed a successful measurement of the Baryonic Acoustic Oscillations (BAO) at multiple cosmic epochs with a high precision.
Based on this measurement and a method developed by Zhao for dark energy studies Cheap Gabriel Paletta Jersey , the Zhao team found an evidence of dynamical dark energy at a significance level of 3.5 sigma. This suggests that the nature of dark energy may not be the vacuum energy, but some kind of dynamical field, especially for the quintom model whose EoS varies with time and crosses the -1 boundary during evolution, according to NAOC.
"As the Zhao team reported in this work, a dynamical dark energy model is able to naturally reconcile tensions between local and primordial measurements of cosmological parameters in the LCDM model," Prof. Xinmin Zhang at the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences (CAS) told Xinhua.
"Which makes a crucial step towards understanding the nature of dark energy," he added.
The dynamics of dark energy needs to be confirmed by next-generation astronomical surveys. The team points to the upcoming Dark Energy Spectroscopic Instrument (DESI) survey Cheap Gabriel Jersey , which aims to begin creating a 3D cosmic map in 2018.
In the next five to ten years, the world largest galaxy surveys will provide observables which may be key to unveil the mystery of dark energy, according to a news release of NAOC.
WELLINGTON, Oct. 12 (Xinhua) -- A New Zealand-led study has opened the way to a global approach to tackling one of the major sources of greenhouse gases, scientists at the government's AgResearch institute said Monday.
The Global Rumen Census project analyzed the microbes responsible for methane emissions from a wide range of ruminant animals around the world and found they were all similar.
Collaborating with 140 researchers from 73 institutions worldwide, the AgResearch-led project found similar bacteria and methanogens dominated in almost all rumens (the foregut of ruminant animals) across a wide variety of species and animal diets.
The study team analyzed the DNA of 742 samples collected over two years, said an AgResearch statement.
As well as the expected samples from sheep Cheap Franck Kessie Jersey , cattle, deer and goats, they also studied some from buffalo and giraffes.
Feed is fermented by the microbes in the rumen, allowing the animal to extract energy from feed such as grasses that otherwise could not be digested, so the microbes are therefore essential for ruminant productivity.
However, a by-product of the fermentation is the greenhouse gas, methane Cheap Fabio Borini Jersey , which is produced by microbes called methanogens.
"The rumen methanogens turned out to be highly similar species in all rumens across the world," AgResearch scientist Dr Peter Janssen said in the statement.
"So, only a few species appear to be responsible for all the methane produced by ruminants everywhere, which means mitigation strategies can be developed to target the few dominant methanogens, " he said.
"That's interesting from a methane mitigation stand point because that means the technology that's developed in one place will be applicable everywhere."
Iowa State University is well known for their technology programs and research, producing some of the world?s leading theorists, writers Cheap Davide Calabria Jersey , and even astronauts, but what of their sports programs? The Cyclones of Iowa State compete in the Big 12 Conference of the NCAA?s 1st Division, a conference generally recognized to be one of the weaker ones in the NCAA, and it?s safe to say their sports program doesn?t have quite the lustre that their academic pursuits do. In fact their men?s baseball and swimming teams recently got shelved due to budget constraints, leaving the school with just 6 men?s teams, while still fielding 10 women?s teams. Many other team sports do still exist at a club sport level, including men?s baseball Cheap Cristian Zapata Jersey , hockey, and swimming, though they don?t enjoy the benefit of NCAA Division 1 competition or exposure.
The Cyclones nickname first came about in 1895, after Iowa State routed Northwestern 36 0, to which a Chicago Tribune reporter remarked that Northwestern would?ve had more success playing against a tornado. Iowa State immediately adopted the name, which was also fitting given the area?s propensity for tornadoes, and created Cy the Cardinal to be their mascot. Their logo has undergone several revisions Cheap Carlos Bacca Jersey , with the most recent version of a graphically intensive and busy logo of a half cardinal, half tornado, a style of logo popular in the 1990?s, being scrapped in favour of a more distinguished logo featuring a capital I superimposed over the word State, in a new font type the school is calling cyclone.
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