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Journal articles on the topic 'Primitive Earth'

Author: Grafiati

Published: 8 June 2024

Last updated: 31 July 2025

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1

Otalora, Fermin, and Juan Manuel García Ruiz. "Investigating the primitive Earth through crystals." Acta Crystallographica Section A Foundations and Advances 74, a2 (2018): e251-e251. http://dx.doi.org/10.1107/s2053273318091398.

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2

Orò, Juan, and Cristiano B. Cosmovici. "Comets and Life on the Primitive Earth." International Astronomical Union Colloquium 161 (January 1997): 97–120. http://dx.doi.org/10.1017/s0252921100014639.

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AbstractComets may have contributed substantial amounts of water, volatiles and organic precursors such as HCN for the synthesis of biochemical compounds on the primitive Earth. This suggestion followed closely the prebiotic synthesis of adenine, purines and amino acids from HCN. Recent studies on the terrestrial heavy noble gases provide evidence that comets are the principal external source of Earth’s volatiles. During the encounter of comet Halley strong jets of CN, C2, C3and NH2were measured from Earth observatories, and by spacecraft mass spectrometry HCN, formaldehyde, adenine and many o

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3

Guo, Dong, Ziyue Zhang, Jichao Sun, Hui Zhao, Wanguo Hou, and Na Du. "A Fusion–Growth Protocell Model Based on Vesicle Interactions with Pyrite Particles." Molecules 29, no. 11 (2024): 2664. http://dx.doi.org/10.3390/molecules29112664.

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Protocell models play a pivotal role in the exploration of the origin of life. Vesicles are one type of protocell model that have attracted much attention. Simple single-chain amphiphiles (SACs) and organic small molecules (OSMs) possess primitive relevance and were most likely the building blocks of protocells on the early Earth. OSM@SAC vesicles have been considered to be plausible protocell models. Pyrite (FeS2), a mineral with primitive relevance, is ubiquitous in nature and plays a crucial role in the exploration of the origin of life in the mineral–water interface scenario. “How do proto

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4

Rao, M., J. Eichberg, and J. Oró. "Synthesis of phosphatidylethanolamine under possible primitive earth conditions." Journal of Molecular Evolution 25, no. 1 (1987): 1–6. http://dx.doi.org/10.1007/bf02100033.

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5

Wong, Carlos, J. Carlos Santiago, Lorena Rodriguez-Paez, Miguel Ibánez, Isabel Baeza, and J. Oró. "Synthesis of putrescine under possible primitive earth conditions." Origins of Life and Evolution of the Biosphere 21, no. 3 (1991): 145–56. http://dx.doi.org/10.1007/bf01809443.

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6

von Bloh, W., C. Bounama, M. Cuntz, and S. Franck. "Habitability of super-Earths: Gliese 581c & 581d." Proceedings of the International Astronomical Union 3, S249 (2007): 503–6. http://dx.doi.org/10.1017/s1743921308017031.

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AbstractThe unexpected diversity of exoplanets includes a growing number of super-Earth planets, i.e., exoplanets with masses smaller than 10 Earth masses. Unlike the larger exoplanets previously found, these smaller planets are more likely to have similar chemical and mineralogical composition to the Earth. We present a thermal evolution model for super-Earth planets to identify the sources and sinks of atmospheric carbon dioxide. The photosynthesis-sustaining habitable zone (pHZ) is determined by the limits of biological productivity on the planetary surface. We apply our model to calculate

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7

Imai, Takashi. "Development of Next-Generation Vaccines." Vaccines 10, no. 2 (2022): 274. http://dx.doi.org/10.3390/vaccines10020274.

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8

Jia, Tony Z., Melina Caudan, and Irena Mamajanov. "Origin of Species before Origin of Life: The Role of Speciation in Chemical Evolution." Life 11, no. 2 (2021): 154. http://dx.doi.org/10.3390/life11020154.

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Speciation, an evolutionary process by which new species form, is ultimately responsible for the incredible biodiversity that we observe on Earth every day. Such biodiversity is one of the critical features which contributes to the survivability of biospheres and modern life. While speciation and biodiversity have been amply studied in organismic evolution and modern life, it has not yet been applied to a great extent to understanding the evolutionary dynamics of primitive life. In particular, one unanswered question is at what point in the history of life did speciation as a phenomenon emerge

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9

YANAGAWA, Hiroshi, Yoko OGAWA, and Masahiko ITO. "Construction of protocellular structures under simulated primitive earth conditions." NIPPON KAGAKU KAISHI, no. 11 (1987): 2186–93. http://dx.doi.org/10.1246/nikkashi.1987.2186.

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10

Chyba, Christopher F. "The cometary contribution to the oceans of primitive Earth." Nature 330, no. 6149 (1987): 632–35. http://dx.doi.org/10.1038/330632a0.

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11

Yanagawa, Hiroshi, Yoko Ogawa, Kiyotsugu Kojima, and Masahiko Ito. "Construction of protocellular structures under simulated primitive earth conditions." Origins of Life and Evolution of the Biosphere 18, no. 3 (1988): 179–207. http://dx.doi.org/10.1007/bf01804670.

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12

Tsuji, Toru, and Kensei Kobayashi. "Abiotic formation of uracil from simulted primitive Earth atmosphere." Origins of Life and Evolution of the Biosphere 26, no. 3-5 (1996): 347–48. http://dx.doi.org/10.1007/bf02459801.

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13

Bhandari, N. "Primitive Matter in Meteorites." Symposium - International Astronomical Union 120 (1987): 485–91. http://dx.doi.org/10.1017/s0074180900154506.

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A large number of elements in certain meteorites have isotopic composition different from that existing in rocks of the earth or the moon. Excess amounts of some isotopes, which are radiogenic daughters, are attributed to the in situ decay of their parent nuclide. Material containing radioactive parents is believed to have been injected into the condensing solar nebula, from astrophysical sites of their production shortly before formation of these grains. Other isotopic anomalies do not show mass dependent pattern which is characteristic of chemical fractionation. They must be primary isotopic

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14

Samulewski, Rafael Block, Josué Martins Gonçalves, Alexandre Urbano, et al. "Magnetite Synthesis in the Presence of Cyanide or Thiocyanate under Prebiotic Chemistry Conditions." Life 10, no. 4 (2020): 34. http://dx.doi.org/10.3390/life10040034.

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Magnetite is an iron oxide mineral component of primitive Earth. It is naturally synthesized in different ways, such as magma cooling as well as olivine decomposition under hydrothermal conditions. It is probable magnetite played a significant role in biogenesis. The seawater used in the current work contained high Mg2+, Ca2+ and SO42− concentrations, unlike the seawater of today that has high Na+ and Cl− concentrations. It is likely that this seawater better resembled the ion composition of the seas of the Earth from 4 billion years ago. Cyanide and thiocyanate were common molecules in prebio

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15

Furukawa, Yoshihiro, Yoshito Chikaraishi, Naohiko Ohkouchi, et al. "Extraterrestrial ribose and other sugars in primitive meteorites." Proceedings of the National Academy of Sciences 116, no. 49 (2019): 24440–45. http://dx.doi.org/10.1073/pnas.1907169116.

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Sugars are essential molecules for all terrestrial biota working in many biological processes. Ribose is particularly essential as a building block of RNA, which could have both stored information and catalyzed reactions in primitive life on Earth. Meteorites contain a number of organic compounds including key building blocks of life, i.e., amino acids, nucleobases, and phosphate. An amino acid has also been identified in a cometary sample. However, the presence of extraterrestrial bioimportant sugars remains unclear. We analyzed sugars in 3 carbonaceous chondrites and show evidence of extrate

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16

Rossi, Riikka. "Transgression, Nostalgia, Order: Representation of the Primitive in Émile Zola's La Terre and Knut Hamsun's Markens grøde <\i>." Nordlit 15, no. 2 (2012): 257. http://dx.doi.org/10.7557/13.2282.

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This article examines the representation of the primitive in two peasant novels, Émile Zola's La Terre (1887, trans. as The Earth) and Knut Hamsun's Markens grøde (1917, trans. as Growth of the Soil). The concept of the primitive crosses a wide range of issues that were central to naturalist and decadent literature at the turn of the twentieth century, from unconscious instincts to the fascination with exotic cultures. It thus offers a fruitful medium for the comparative reading of French and Nordic fiction of the era. I especially focus on analysing the diverse, representative practices of Zo

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17

Hui, Zhenyang, Zhaochen Cai, Bo Liu, Dajun Li, Hua Liu, and Zhuoxuan Li. "A Self-Adaptive Optimization Individual Tree Modeling Method for Terrestrial LiDAR Point Clouds." Remote Sensing 14, no. 11 (2022): 2545. http://dx.doi.org/10.3390/rs14112545.

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Individual tree modeling for terrestrial LiDAR point clouds always involves heavy computation burden and low accuracy toward a complex tree structure. To solve these problems, this paper proposed a self-adaptive optimization individual tree modeling method. In this paper, we first proposed a joint neighboring growing method to segment wood points into object primitives. Subsequently, local object primitives were optimized to alleviate the computation burden. To build the topology relation among branches, branches were separated based on spatial connectivity analysis. And then the nodes corresp

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18

Barbier, Bernard, Marylène Bertrand, François Boillot, et al. "Delivery of extraterrestrial amino acids to the primitive Earth. Exposure experiments in Earth orbit." Biological Sciences in Space 12, no. 2 (1998): 92–95. http://dx.doi.org/10.2187/bss.12.92.

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19

Harisman, Yulyanti, Difa Aziza, Muchamad Subali Noto, Lukman Harun, and Marwia Tamrin Bakar. "“BAGAIMANA ORANG-ORANG DI ZAMAN PRIMITIF BERHITUNG?“ STUDI KASUS PADA MAHASISWA CALON GURU." Teorema: Teori dan Riset Matematika 8, no. 1 (2023): 128. http://dx.doi.org/10.25157/teorema.v8i1.9154.

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Pada zaman primitif perhitungan sudah digunakan dengan cara sederhana. Penelitian ini akan memaparkan bagaimana proses berpikir cara berhitung pada zaman primitif. Selanjutnya proses berpikir yang dilakukan dieksternalisasikan dengan proses berpikir cara berhitung pada siswa zaman sekarang, dan mengetahui sejauh mana pengetahuan mahasiswa calon guru tentang bagaimana orang primitif berhitung. Jenis penelitian ini ialah penelitian kualitatif dengan metode meta analisis dan studi kasus. Meta analisis menggunakan beberapa jurnal dan buku, selanjutnya kurikulum pada sekolah di analisis dan dicari

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20

Demongeot, Jacques, and Michel Thellier. "Primitive Oligomeric RNAs at the Origins of Life on Earth." International Journal of Molecular Sciences 24, no. 3 (2023): 2274. http://dx.doi.org/10.3390/ijms24032274.

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There are several theories on the origin of life, which differ by choosing the preponderant factor of emergence: main function (autocatalysis versus replication), initial location (black smokers versus ponds) or first molecule (RNA versus DNA). Among the two last ones, the first assumes that an RNA world involving a collaboration of small RNAs with amino-acids pre-existed and the second that DNA–enzyme–lipid complexes existed first. The debate between these classic theories is not closed and the arguments for one or the other of these theories have recently fueled a debate in which the two hav

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21

Bhakuni, D. S. "Prebiotic organic chemistry and the origin of life." Journal of Palaeosciences 41 (December 31, 1992): 9–17. http://dx.doi.org/10.54991/jop.1992.1100.

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Prebiotic synthesis of organic compounds such as amino, hydroxyl and aliphatic acids, urea, imidazoles and synthesis of amino acids, co-enzymes, nucleosides under primitive earth conditions have been reviewed.

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22

Michel, Patrick. "MarcoPolo-R: Near Earth Asteroid Sample Return Mission candidate as ESA-M3 class mission." Proceedings of the International Astronomical Union 10, H16 (2012): 483. http://dx.doi.org/10.1017/s1743921314011879.

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AbstractMarcoPolo-R is a sample return mission to a primitive Near-Earth Asteroid (NEA) selected in 2011 for the Assessment Study Phase of M3-class missions in the framework of ESAs Cosmic Vision (CV) 2015-2025 programme. The phase A study started at the end of 2012 and will proceed throughout 2013. The final selection by ESA will occur in February 2014. MarcoPolo-R is a European-led mission with a possible contribution from other agencies. MarcoPolo-R will rendez-vous with the primitive NEA 2008 EV5. Before returning a unique sample to Earth, the asteroid will be scientifically characterized

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Michel, Patrick, Luisa-M. Lara, Bernard Marty, et al. "MarcoPolo-R: Near Earth Asteroid Sample Return Mission candidate as ESA-M3 class mission." Proceedings of the International Astronomical Union 10, H16 (2012): 163. http://dx.doi.org/10.1017/s1743921314005183.

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AbstractMarcoPolo-R is a sample return mission to a primitive Near-Earth Asteroid (NEA) selected in February 2011 for the Assessment Study Phase at ESA in the framework of ESAfs Cosmic Vision 2 program. MarcoPolo-R is a European-led mission with a proposed NASA contribution. MarcoPolo-R takes advantage of three industrial studies completed as part of the previous Marco Polo mission (see ESA/SRE (2009)3). The aim of the new Assessment Study is to reduce the cost of the mission while maintaining its high science level, on the basis of advanced studies and technologies, as well as optimization of

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24

Towe, Kenneth M. "Biochemical Innovations, Oxygen and Earth History." Short Courses in Paleontology 1 (1988): 114–29. http://dx.doi.org/10.1017/s2475263000000714.

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It is conventional to view the origin and early evolution of life as having taken place beneath an atmosphere devoid of free oxygen. Of primary concern is the fact that experiments designed to produce simple prebiotic compounds as precursor “building-blocks” for life are generally successful only if free oxygen is lacking from the starting mixture of gases. Clearly, life could hardly have evolved in the absence of suitable starting materials. Secondly, organic compounds are thermodynamically susceptible to oxygen and, given enough time, will become oxidized, ultimately to carbon dioxide. A cen

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25

Ishigami, Masahiro, Hideshi Ihara, and Hiroyuki Shinoda. "Molecular Evolution of Aminoacyl tRNA Synthetases and Origin of Universal Genetic Code." International Astronomical Union Colloquium 161 (January 1997): 483–89. http://dx.doi.org/10.1017/s0252921100015013.

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AbstractIt is thought that living things first appeared on the primitive earth 35 hundred million years ago. At that time, a primitive protein synthesis mechanism was thought to have been established, a genetic code system evolved, and a universal genetic code system developed. Aminoacyl tRNA synthetase must have evolved with the genetic code system. The aim of the present study is to clarify the evolution of aminoacyl tRNA synthetase and the process and era of the establishment of the universal genetic code system.

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26

Pettitt, Paul B., and Mark J. White. "Cave men: Stone tools, Victorian science, and the ‘primitive mind’ of deep time." Notes and Records of the Royal Society 65, no. 1 (2010): 25–42. http://dx.doi.org/10.1098/rsnr.2010.0100.

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Palaeoanthropology, the study of the evolution of humanity, arose in the nineteenth century. Excavations in Europe uncovered a series of archaeological sediments which provided proof that the antiquity of human life on Earth was far longer than the biblical six thousand years, and by the 1880s authors had constructed a basic paradigm of what ‘primitive’ human life was like. Here we examine the development of Victorian palaeoanthropology for what it reveals of the development of notions of cognitive evolution. It seems that Victorian specialists rarely addressed cognitive evolution explicitly,

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27

Hanczyc, Martin M. "Metabolism and motility in prebiotic structures." Philosophical Transactions of the Royal Society B: Biological Sciences 366, no. 1580 (2011): 2885–93. http://dx.doi.org/10.1098/rstb.2011.0141.

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Easily accessible, primitive chemical structures produced by self-assembly of hydrophobic substances into oil droplets may result in self-moving agents able to sense their environment and move to avoid equilibrium. These structures would constitute very primitive examples of life on the Earth, even more primitive than simple bilayer vesicle structures. A few examples of simple chemical systems are presented that self-organize to produce oil droplets capable of movement, environment remodelling and primitive chemotaxis. These chemical agents are powered by an internal chemical reaction based on

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28

Ringwood, A. E. "The Earth-Moon Connection." Zeitschrift für Naturforschung A 44, no. 10 (1989): 891–923. http://dx.doi.org/10.1515/zna-1989-1004.

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Abstract The early thermal state of the Earth provides important constraints on hypotheses relating to its origin and its connection with the Moon. The currently popular giant impact hypothesis of lunar origin requires the Earth’s mantle to have been completely melted during the impact. Differentiation of a molten mantle would have produced strong chemical and mineralogical stratification, causing the mantle to become gravitationally stable and resistant to convective rehomogenization. The resulting composition and mineralogy of the upper mantle and primitive crust would have been dramatically

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Arai, Noriyoshi, Yusei Kobayashi, and Kenji Yasuoka. "A biointerface effect on the self-assembly of ribonucleic acids: a possible mechanism of RNA polymerisation in the self-replication cycle." Nanoscale 12, no. 12 (2020): 6691–98. http://dx.doi.org/10.1039/c9nr09537c.

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The self-assembly was found to be more favoured in a vesicle-cell membrane, rather than in the bulk system. The result will contribute to a better understanding of the origin of life on the primitive Earth.

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30

Gururani, Kavita. "Acetonitrile: A Plausible Source of Amino Acids on the Primitive Earth." IOSR Journal of Applied Chemistry 2, no. 2 (2012): 43–48. http://dx.doi.org/10.9790/5736-0224348.

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31

Wade, Jon, Brendan Dyck, Richard M. Palin, James D. P. Moore, and Andrew J. Smye. "The divergent fates of primitive hydrospheric water on Earth and Mars." Nature 552, no. 7685 (2017): 391–94. http://dx.doi.org/10.1038/nature25031.

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32

KOBAYASHI, Tetsuo. "Metabolic Properties of Marine Hyperthermophiles, The Most Primitive Organisms on Earth." Kagaku To Seibutsu 33, no. 12 (1995): 796–802. http://dx.doi.org/10.1271/kagakutoseibutsu1962.33.796.

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33

Shimizu, Mikio. "Violent Primitive Earth Might have Harmonized with the Origin of Life." International Astronomical Union Colloquium 161 (January 1997): 431–36. http://dx.doi.org/10.1017/s0252921100014949.

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AbstractAt the end of the planetesimal infall on the surface of the primitive earth, hot dry beaches might have been useful for the formation of various activated monomers and oligomers (peptides and small RNAs). We discuss the possibility that a small system composed of small RNAs (∼ 10 mers) and dipeptides might have mimicked the contemporary biosystem, based on experimental results suggesting the presence of previously overlooked weak but specific interactions between three bases and one amino acid (of genetic code type) and also those between a dipeptide and a biosubstrate (of ligase, tran

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KAWAKATSU, Yasuhiro, Masanao ABE, and Jun'ichiro KAWAGUCHI. "Mission Analysis for Sample Retrieval from a Primitive Near-Earth Asteroid." TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN 7 (2009): 33–41. http://dx.doi.org/10.2322/tstj.7.33.

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35

Coustenis, A. "Titan's atmosphere and surface: Parallels and differences with the primitive Earth." Earth, Moon, and Planets 67, no. 1-3 (1994): 95–100. http://dx.doi.org/10.1007/bf00613295.

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36

Estévez, Carles. "Alkyl chlorides in the primitive Earth: Implications for prebiotic chemical evolution." Origins of Life and Evolution of the Biosphere 26, no. 3-5 (1996): 338–39. http://dx.doi.org/10.1007/bf02459795.

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37

Chisholm, Michael, and Richard Hodges. "Primitive and Peasant Markets." Geographical Journal 155, no. 2 (1989): 270. http://dx.doi.org/10.2307/635097.

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38

Huang, Liu, Wang, Zheng, Wang, and Ming. "Change Detection of High Spatial Resolution Images Based on Region-Line Primitive Association Analysis and Evidence Fusion." Remote Sensing 11, no. 21 (2019): 2484. http://dx.doi.org/10.3390/rs11212484.

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Change detection (CD) remains an important issue in remote sensing applications, especially for high spatial resolution (HSR) images, but it has yet to be fully resolved. This work proposes a novel object-based change detection (OBCD) method for HSR images that is based on region–line primitive association analysis and evidence fusion. In the proposed method, bitemporal images are separately segmented, and the segmentation results are overlapped to obtain the temporal region primitives (TRPs). The temporal line primitives (TLPs) are obtained by straight line detection on bitemporal images. In

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Mulder, Thomas E., Heiko Goelzer, Fred W. Wubs, and Henk A. Dijkstra. "Snowball Earth Bifurcations in a Fully-Implicit Earth System Model." International Journal of Bifurcation and Chaos 31, no. 06 (2021): 2130017. http://dx.doi.org/10.1142/s0218127421300172.

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There is now much geological evidence that the Earth was fully glaciated during several periods in the geological past (about 700[Formula: see text]Myr ago) and attained a so-called Snowball Earth (SBE) state. Additional support for this idea has come from climate models of varying complexity that show transitions to SBE states and undergo hysteresis under changes in solar radiation. In this paper, we apply large-scale bifurcation analyses to a novel, fully-implicit Earth System Model of Intermediate Complexity (I-EMIC) to study SBE transitions. The I-EMIC contains a primitive equation ocean m

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Cary, Francesca C. A., David W. Deamer, Bruce F. Damer, Sarah A. Fagents, Kathleen C. Ruttenberg, and Stuart P. Donachie. "Could Life Have Started on Mars? Planetary Conditions That Assemble and Destroy Protocells." Life 14, no. 3 (2024): 415. http://dx.doi.org/10.3390/life14030415.

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Early Mars was likely habitable, but could life actually have started there? While cellular life emerged from prebiotic chemistry through a pre-Darwinian selection process relevant to both Earth and Mars, each planet posed unique selection ‘hurdles’ to this process. We focus on drivers of selection in prebiotic chemistry generic to Earth-like worlds and specific to Mars, such as an iron-rich surface. Iron, calcium, and magnesium cations are abundant in hydrothermal settings on Earth and Mars, a promising environment for an origin of life. We investigated the impact of cations on the stability

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Ge, Xuming, Bo Wu, Yuan Li, and Han Hu. "A Multi-Primitive-Based Hierarchical Optimal Approach for Semantic Labeling of ALS Point Clouds." Remote Sensing 11, no. 10 (2019): 1243. http://dx.doi.org/10.3390/rs11101243.

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There are normally three main steps to carrying out the labeling of airborne laser scanning (ALS) point clouds. The first step is to use appropriate primitives to represent the scanning scenes, the second is to calculate the discriminative features of each primitive, and the third is to introduce a classifier to label the point clouds. This paper investigates multiple primitives to effectively represent scenes and exploit their geometric relationships. Relationships are graded according to the properties of related primitives. Then, based on initial labeling results, a novel, hierarchical, and

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Gregory, C. A., and Richard Hodges. "Primitive and Peasant Markets." Man 24, no. 2 (1989): 358. http://dx.doi.org/10.2307/2803326.

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43

Banerjee, Ruma. "The Earth through time, the key of biological diversity." International Journal of Advanced Research Trends in Science 2, no. 1 (2023): i. http://dx.doi.org/10.70035/ijarts.2023.21i.

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Controversy arises with the passage of time by the development of intellect and critical thoughts on the discovery of the theories of the Earth’s origin from primitive to modern hypotheses. The scientists explore the geological history of the Earth by chronostatigraphy or time based monitoring of rock record through geological time scale. Since the evidence is currently insufficient, scientists will need to make more advancement in the study of the origin and evolution of early life. The primitive unicellular organisms existed in an atmosphere made up of gases like methane and ammonia that was

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Nicholls, Elizabeth L., and Donald Brinkman. "A new specimen of Utatsusaurus (Reptilia: Ichthyosauria) from the Lower Triassic Sulphur Mountain Formation of British Columbia." Canadian Journal of Earth Sciences 30, no. 3 (1993): 486–90. http://dx.doi.org/10.1139/e93-037.

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An incomplete skull and mandible of the primitive ichthyosaur Utatsusaurus is described from the Lower Triassic Vega Phroso Member of the Sulphur Mountain Formation of British Columbia. The specimen contributes to our knowledge of the cranial anatomy of the genus, which was previously known primarily from postcranial material, and extends its geographic range to Canada. The presence of an isodont dentition in this primitive genus suggests that isodonty rather than heterodonty may be the primitive character state for the Ichthyosauria.

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Saha, Arpita, Ruiqin Yi, Albert C. Fahrenbach, Anna Wang, and Tony Z. Jia. "A Physicochemical Consideration of Prebiotic Microenvironments for Self-Assembly and Prebiotic Chemistry." Life 12, no. 10 (2022): 1595. http://dx.doi.org/10.3390/life12101595.

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The origin of life on Earth required myriads of chemical and physical processes. These include the formation of the planet and its geological structures, the formation of the first primitive chemicals, reaction, and assembly of these primitive chemicals to form more complex or functional products and assemblies, and finally the formation of the first cells (or protocells) on early Earth, which eventually evolved into modern cells. Each of these processes presumably occurred within specific prebiotic reaction environments, which could have been diverse in physical and chemical properties. While

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Martins, Zita, and Matthew A. Pasek. "Delivery of Organic Matter to the Early Earth." Elements 20, no. 1 (2024): 19–23. http://dx.doi.org/10.2138/gselements.20.1.19.

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The inner Solar System—including the planet Earth—was heavily bombarded by comets, asteroids, and their fragments (i.e., meteorites, micrometeorites, and interplanetary dust particles) from 4.56 to about 3.5 billion years ago. This bombardment resulted in a rich assortment of organics delivered to the Earth, as comets and many asteroids contain carbonaceous material. These organic compounds were likely further processed on the early Earth (e.g., by impact-shock reactions), providing a feedstock of prebiotic molecules to the crust and oceans. In this chapter, we review the mechanisms of organic

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Tazaki, Kazue, and W. S. Fyfe. "Primitive clay precursors formed on feldspar." Canadian Journal of Earth Sciences 24, no. 3 (1987): 506–27. http://dx.doi.org/10.1139/e87-051.

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High-resolution transmission electron microscopy of clay formation on K-feldspar has revealed the existence of intermediate states between feldspar and crystalline clay products. During the earliest weathering stages of K-feldspar, a primitive clay precursor forms on the feldspar surface that is spotted by ion oxides. This reactive iron is incorporated into the primitive clay precursors, which have an ultrathin 150–200 Å (1 Å = 0.1 nm) circular form and 14–20 Å lattice images or long, curled fiber forms with varied lattice image spacings. The electron diffraction patterns of primitive clay pre

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Morate, David, Julia de León, Mário De Prá, et al. "Visible spectroscopy of the Sulamitis and Clarissa primitive families: a possible link to Erigone and Polana." Astronomy & Astrophysics 610 (February 2018): A25. http://dx.doi.org/10.1051/0004-6361/201731407.

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The low-inclination (i< 8∘) primitive asteroid families in the inner main belt, that is, Polana-Eulalia, Erigone, Sulamitis, and Clarissa, are considered to be the most likely sources of near-Earth asteroids (101955) Bennu and (162173) Ryugu. These two primitive NEAs will be visited by NASA OSIRIS-REx and JAXA Hayabusa 2 missions, respectively, with the aim of collecting samples of material from their surfaces and returning them back to Earth. In this context, the PRIMitive Asteroid Spectroscopic Survey (PRIMASS) was born, with the main aim to characterize the possible origins of these NEAs

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Brazeau, Martin D. "A new genus of rhizodontid (Sarcopterygii, Tetrapodomorpha) from the Lower Carboniferous Horton Bluff Formation of Nova Scotia, and the evolution of the lower jaws in this group." Canadian Journal of Earth Sciences 42, no. 8 (2005): 1481–99. http://dx.doi.org/10.1139/e05-041.

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Letognathus gen. nov. is described from the Lower Carboniferous (Tournaisian) Horton Bluff Formation. Included in this genus is the species Letognathus hardingi (Dawson 1868), which was originally assigned toRhizodus and later toStrepsodus, but it is distinct from these genera in tooth morphology and the presence of several more primitive rhizodontid characters. By contrast with these latter more derived genera, the parasymphysial plate contacts the first coronoid; the first coronoid bears a row of lingually deflected teeth, the tooth striations occur around the entire circumference of the cro

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Zhou, Hao, Zheng Ji, Xiangyu You, et al. "Geometric Primitive-Guided UAV Path Planning for High-Quality Image-Based Reconstruction." Remote Sensing 15, no. 10 (2023): 2632. http://dx.doi.org/10.3390/rs15102632.

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Image-based refined 3D reconstruction relies on high-resolution and multi-angle images of scenes. The assistance of multi-rotor drones and gimbal provides great convenience for image acquisition. However, capturing images with manual control generally takes a long time. It could easily lead to redundant or insufficient local area coverage, resulting in poor quality of the reconstructed model. We propose a surface geometric primitive-guided UAV path planning method (SGP-G) that aims to automatically and quickly plan a collision-free path to capture fewer images, based on which high-quality mode

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