2010. május 23., vasárnap
2010. május 21., péntek
Antimatter particles are sub-atomic particles with properties opposite those of normal matter particles. For example, a positron is the antiparticle equivalent of the electron and has a positive charge. When a particle and its antiparticle meet, they annihilate, releasing massive amounts of energy, according to Einstein's famous equation E=mc^2, where E is equal to energy, m is equal to mass, and c is the speed of light.
Antimatter particles are created in ultra high-speed collisions. In the first moments after the Big Bang, only energy existed. As the universe cooled and expanded, particles of both matter and antimatter were produced in equal amounts.
Antimatter particles are created in ultra high-speed collisions. In the first moments after the Big Bang, only energy existed. As the universe cooled and expanded, particles of both matter and antimatter were produced in equal amounts.
2010. május 16., vasárnap
Scientists who study the brain have found that different thoughts and feelings create specific chemical reactions in the brain, and that the more these reactions happen the more the brain becomes "wired" to think and feel that way.
Do something with the thoughts rather than just thinking them. Write in a journal, talk to a friend.
Do something that will help you feel amused, relaxed, loved, energized or accomplished - all of which will create positive chemistry in your brain.
Do something with the thoughts rather than just thinking them. Write in a journal, talk to a friend.
Do something that will help you feel amused, relaxed, loved, energized or accomplished - all of which will create positive chemistry in your brain.
2010. május 10., hétfő
Without Nickel, Life on Earth Could Finally Breathe
Written by Anne Minard
Caption: Banded iron formations like this from northern Michigan contain evidence of a drop in dissolved nickel in ancient oceans. Credit: Carnegie Institution for Science
Caption: Banded iron formations like this from northern Michigan contain evidence of a drop in dissolved nickel in ancient oceans. Credit: Carnegie Institution for Science
Researchers have long puzzled over why oxygen flourished in Earth's atmosphere starting around 2.4 billion years.
Called the "Great Oxidation Event," the transition "irreversibly changed surface environments on Earth and ultimately made advanced life possible," said Dominic Papineau of the Carnegie Institution's Geophysical Laboratory.
Now, Papineau has co-authored a new study in the journal Nature, which reveals new clues to the mystery in ancient sedimentary rocks.
The research team, led by Kurt Konhauser of the University of Alberta in Edmonton, analyzed the trace element composition of sedimentary rocks known as banded-iron formations, or BIFs, from dozens of different localities around the world, ranging in age from 3,800 to 550 million years. Banded iron formations are unique, water-laid deposits often found in extremely old rock strata that formed before the atmosphere or oceans contained abundant oxygen. As their name implies, they are made of alternating bands of iron and silicate minerals.
They also contain minor amounts of nickel and other trace elements. And the history of nickel, the researchers think, may reveal a secret to the origin of modern life.
Nickel exists in today's oceans in trace amounts, but was up to 400 times more abundant in the Earth's primordial oceans. Methane-producing microorganisms, called methanogens, thrive in such environments, and the methane they released to the atmosphere might have prevented the buildup of oxygen gas, which would have reacted with the methane to produce carbon dioxide and water.
A drop in nickel concentration would have led to a "nickel famine" for the methanogens, who rely on nickel-based enzymes for key metabolic processes. Algae and other organisms that release oxygen during photosynthesis use different enzymes, and so would have been less affected by the nickel famine. As a result, atmospheric methane would have declined, and the conditions for the rise of oxygen would have been set in place.
The researchers found that nickel levels in the BIFs began dropping around 2.7 billion years ago and by 2.5 billion years ago was about half its earlier value.
"The timing fits very well. The drop in nickel could have set the stage for the Great Oxidation Event," Papineau said. "And from what we know about living methanogens, lower levels of nickel would have severely cut back methane production."
As for why nickel dropped in the first place, the researchers point to geology. During earlier phases of the Earth's history, while its mantle was extremely hot, lavas from volcanic eruptions would have been relatively high in nickel. Erosion would have washed the nickel into the sea, keeping levels high. But as the mantle cooled, and the chemistry of lavas changed, volcanoes spewed out less nickel, and less would have found its way to the sea.
"The nickel connection was not something anyone had considered before," Papineau said. "It's just a trace element in seawater, but our study indicates that it may have had a huge impact on the Earth's environment and on the history of life."
Source: Carnegie Institution for Science, via Eurekalert.
Written by Anne Minard
Caption: Banded iron formations like this from northern Michigan contain evidence of a drop in dissolved nickel in ancient oceans. Credit: Carnegie Institution for Science
Caption: Banded iron formations like this from northern Michigan contain evidence of a drop in dissolved nickel in ancient oceans. Credit: Carnegie Institution for Science
Researchers have long puzzled over why oxygen flourished in Earth's atmosphere starting around 2.4 billion years.
Called the "Great Oxidation Event," the transition "irreversibly changed surface environments on Earth and ultimately made advanced life possible," said Dominic Papineau of the Carnegie Institution's Geophysical Laboratory.
Now, Papineau has co-authored a new study in the journal Nature, which reveals new clues to the mystery in ancient sedimentary rocks.
The research team, led by Kurt Konhauser of the University of Alberta in Edmonton, analyzed the trace element composition of sedimentary rocks known as banded-iron formations, or BIFs, from dozens of different localities around the world, ranging in age from 3,800 to 550 million years. Banded iron formations are unique, water-laid deposits often found in extremely old rock strata that formed before the atmosphere or oceans contained abundant oxygen. As their name implies, they are made of alternating bands of iron and silicate minerals.
They also contain minor amounts of nickel and other trace elements. And the history of nickel, the researchers think, may reveal a secret to the origin of modern life.
Nickel exists in today's oceans in trace amounts, but was up to 400 times more abundant in the Earth's primordial oceans. Methane-producing microorganisms, called methanogens, thrive in such environments, and the methane they released to the atmosphere might have prevented the buildup of oxygen gas, which would have reacted with the methane to produce carbon dioxide and water.
A drop in nickel concentration would have led to a "nickel famine" for the methanogens, who rely on nickel-based enzymes for key metabolic processes. Algae and other organisms that release oxygen during photosynthesis use different enzymes, and so would have been less affected by the nickel famine. As a result, atmospheric methane would have declined, and the conditions for the rise of oxygen would have been set in place.
The researchers found that nickel levels in the BIFs began dropping around 2.7 billion years ago and by 2.5 billion years ago was about half its earlier value.
"The timing fits very well. The drop in nickel could have set the stage for the Great Oxidation Event," Papineau said. "And from what we know about living methanogens, lower levels of nickel would have severely cut back methane production."
As for why nickel dropped in the first place, the researchers point to geology. During earlier phases of the Earth's history, while its mantle was extremely hot, lavas from volcanic eruptions would have been relatively high in nickel. Erosion would have washed the nickel into the sea, keeping levels high. But as the mantle cooled, and the chemistry of lavas changed, volcanoes spewed out less nickel, and less would have found its way to the sea.
"The nickel connection was not something anyone had considered before," Papineau said. "It's just a trace element in seawater, but our study indicates that it may have had a huge impact on the Earth's environment and on the history of life."
Source: Carnegie Institution for Science, via Eurekalert.
2010. május 7., péntek
próbálkozzak egy sajáttal.. van annak jó ideje, hogy késztetést éreztem bármit is létrehozni.. ágyam mellett ott a napló, nem kívánok írni bele.. szekrénykémben ott a festék, nem kívánok mázolgatni vele.. sötöbö, sötöbö, depresszió előjelei, hintázok már néhány hete
mamánál jó volt, feladatokat adott nekem, elvégeztem, kifáradtam, hasznosnak éreztem magam.. itthon ugyanazokat a dolgokat megtehetném, inkább alszom.. mikor egyedül voltam, szívesen jöttem haza, szívesen végeztem az itthoni teendőimet
höm.. nem hiába kerülöm az írást, cseppet se tetszik ami kijön belőlem (rock on H.P.P.)
joy to the world
mamánál jó volt, feladatokat adott nekem, elvégeztem, kifáradtam, hasznosnak éreztem magam.. itthon ugyanazokat a dolgokat megtehetném, inkább alszom.. mikor egyedül voltam, szívesen jöttem haza, szívesen végeztem az itthoni teendőimet
höm.. nem hiába kerülöm az írást, cseppet se tetszik ami kijön belőlem (rock on H.P.P.)
joy to the world
2010. május 6., csütörtök
In ultima sedinta de Guvern, Cabinetul Boc a „rascolit" prin pusculita goala a bugetului si a mai gasit niste zeci de milioane de lei pentru achitarea datoriilor politice. Datorii facute in campania pentru prezidentiale sau, ulterior, in contextul negocierilor cu partenerii de guvernare. Mai intai, Cabinetul Boc a suplimentat bugetul Secretariatului General al Guvernului cu 18,5 milioane lei, pentru a putea apoi, la pasul doi, sa repartizeze nu mai putin de 54,5 milioane lei catre 1.334 de unitati de cult. Sumele acordate variaza intre 1.000 de lei si 1,2 milioane lei (cazul Catedralei Episcopale „Invierea Domnului" din Municipiul Caransebes). Odata rezolvata „sustinerea cultelor", Guvernul s-a „ingrijit" de scoli si unitati sanitare. Doar ca sumele sunt mult mai mici in aceste cazuri: 31,3 milione lei pentru 348 de unitati de invatamant si, respectiv, 6,3 milioane lei pentru 40 de unitati sanitare.
http://www.romanialibera.ro/actualitate/politica/boc-ia-de-la-scoli-da-la-biserici-185474.html
http://www.romanialibera.ro/actualitate/politica/boc-ia-de-la-scoli-da-la-biserici-185474.html
2010. május 4., kedd
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