マーチソンからのヒボニット粒子の短命なヌクリド:太陽系進化の証拠
K K Marhas1, J N Goswami, A M Davis
1Physical Research Laboratory, Ahmedabad 380009, India.
まとめ
短命のベリリウム-10 (10Be) は,マーチソン隕石のヒボニット粒に検出され,その起源は太陽の星雲の中のエネルギー粒子放射から生じたことを示している. この発見は,初期の太陽系固体への恒星核合成の貢献を区別するのに役立ちます.
科学分野:
- 宇宙化学 (コスモケミストリー)
- 核天体物理学 核天体物理学とは
- 惑星科学は惑星科学である.
背景:
- 隕石の短命な核酸は,太陽系形成の洞察を与えてくれます.
- ヒボニット粒は,太陽系の初期状態を研究するための重要なミネラルフェーズです.
研究 の 目的:
- 初期の太陽系固体における短命なヌクリドの存在と起源を調査する.
- 核合成プロセスを制限するために隕石の同位体異常を利用する.
主な方法:
- マーチソン隕石からのヒボニット粒子の分析.
- 同位体組成の測定,特にベリリウム10 (10Be) 腐敗に起因するボロン10 (10B) 過剰に焦点を当てた.
- アルミニウム-26 (26Al) とカルシウム-41 (41Ca) の予想される豊富さの比較.
主要な成果:
- 過剰な10Bはヒボナイトの粒に検出され,10Beの腐敗と一致しました.
- 研究した穀物には26Alまたは41Caの分解の証拠は見つかりませんでした.
- 観測された10Beの豊富さは,エネルギー粒子放射によって説明できる.
結論:
- エネルギー粒子放射は,初期の太陽星雲における10Beの妥当な源である.
- 26Alと41Caの分解産物の欠如は,これらの核酸が粒子の放射線ではなく,恒星の源から発生した可能性が高いことを示唆しています.
- この研究は,初期の太陽系の元素の核合成起源を区別するのに役立ちます.
さらに関連する動画
09:32An Array-based Comparative Genomic Hybridization Platform for Efficient Detection of Copy Number Variations in Fast Neutron-induced Medicago truncatula Mutants
Published on: November 8, 2017
10:08Surveying Low-Cost Methods to Measure Lifespan and Healthspan in Caenorhabditis elegans
Published on: May 18, 2022
関連する概念動画
In-vitro Mutagenesis
To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes.
Non-vascular Seedless Plants
The diverse plant life on Earth—consisting of nearly 400,000 species—can be divided into three broad categories based on biological characteristics: nonvascular, seedless vascular, and seed plants.
The Evidence for Evolution
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.
Export of Mitochondrial and Chloroplast Genes
A eukaryotic cell can have up to three different types of genetic systems: nuclear, mitochondrial, and chloroplast. During evolution, organelles have exported many genes to the nucleus; this transfer is still ongoing in some plant species. Approximately 18% of the Arabidopsis thaliana nuclear genome is thought to be derived from the chloroplast’s cyanobacterial ancestor, and around 75% of the yeast genome derived from the mitochondria’s bacterial ancestor. This export has occurred irrespective...
Mutations
Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations can be characterized in a number of different ways: whether and how they alter the amino acid sequence of the protein, whether they occur over a small or large area of DNA, and whether they occur in somatic cells or germline cells.
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Genome Size and the Evolution of New Genes
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
