Evolution of Protein Molecules

介绍了Kirk—Othmer Encyclopedia of Chemical Technology（化工技术百科全书）（第五版）电子图书网络版数据库，并对该数据库使用方法和检索途径作出了说明，且结合实例简单地介绍了该数据库的检索方法。

Kirk-Othmer Encyclopedia of Chemical Technology数据库介绍及实例

▪ Abstract This review surveys the observed properties of interstellar dust grains: the wavelength-dependent extinction of starlight, including absorption features, from UV to infrared; optical lum...

https://www.ifa.hawaii.edu/users/reipurth/reviews/draine.pdf

Interstellar dust grains

Gene families are growing rapidly, but standard methods for inferring phylogenies do not scale to alignments with over 10,000 sequences. We present FastTree, a method for constructing large phylogenies and for estimating their reliability. Instead of storing a distance matrix, FastTree stores sequence profiles of internal nodes in the tree. FastTree uses these profiles to implement neighbor-joining and uses heuristics to quickly identify candidate joins. FastTree then uses nearest-neighbor interchanges to reduce the length of the tree. For an alignment with N sequences, L sites, and a different characters, a distance matrix requires O(N^2) space and O(N^2 L) time, but FastTree requires just O( NLa + N sqrt(N) ) memory and O( N sqrt(N) log(N) L a ) time. To estimate the tree's reliability, FastTree uses local bootstrapping, which gives another 100-fold speedup over a distance matrix. For example, FastTree computed a tree and support values for 158,022 distinct 16S ribosomal RNAs in 17 hours and 2.4 gigabytes of memory. Just computing pairwise Jukes-Cantor distances and storing them, without inferring a tree or bootstrapping, would require 17 hours and 50 gigabytes of memory. In simulations, FastTree was slightly more accurate than neighbor joining, BIONJ, or FastME; on genuine alignments, FastTree's topologies had higher likelihoods. FastTree is available at http://microbesonline.org/fasttree.

/pdf/fast-tree-computing-large-minimum-evolution-trees-with-4grq0gwfpy.pdf

Fast Tree: Computing Large Minimum-Evolution Trees with Profiles instead of a Distance Matrix

This is a comprehensive and richly illustrated textbook on the astrophysics of the interstellar and intergalactic medium--the gas and dust, as well as the electromagnetic radiation, cosmic rays, and magnetic and gravitational fields, present between the stars in a galaxy and also between galaxies themselves. Topics include radiative processes across the electromagnetic spectrum; radiative transfer; ionization; heating and cooling; astrochemistry; interstellar dust; fluid dynamics, including ionization fronts and shock waves; cosmic rays; distribution and evolution of the interstellar medium; and star formation. While it is assumed that the reader has a background in undergraduate-level physics, including some prior exposure to atomic and molecular physics, statistical mechanics, and electromagnetism, the first six chapters of the book include a review of the basic physics that is used in later chapters. This graduate-level textbook includes references for further reading, and serves as an invaluable resource for working astrophysicists. * Essential textbook on the physics of the interstellar and intergalactic medium * Based on a course taught by the author for more than twenty years at Princeton University * Covers radiative processes, fluid dynamics, cosmic rays, astrochemistry, interstellar dust, and more * Discusses the physical state and distribution of the ionized, atomic, and molecular phases of the interstellar medium * Reviews diagnostics using emission and absorption lines * Features color illustrations and detailed reference materials in appendices * Instructor's manual with problems and solutions (available only to teachers)

Physics of the Interstellar and Intergalactic Medium

ISO Observations of Gas and Dust Chemistry in Star-Forming Regions

/pdf/radiation-dosimetry-from-a-nanosat-lander-system-for-mars-au3ttg41xm.pdf

Radiation Dosimetry From a Nanosat Lander System for Mars. Orlando Santos 1 , Eric Benton 2 , Lawrence Pin-

We will present the results from the exposure of the metalloporphyrin iron tetraphenylporphyrin chloride (FeTPPCI), anthraufin (C(sub 14)H(sub 8)(O sub 4) (Anth) and Isoviolanthrene (C(sub 34H sub 18) (IVA) to the outher space environment, measured in situ aboard the Organism/Organic Exposure to Orbital Stresses nanosatellite. The compounds were exposed for a period of 17 months (3700 hours of direct solar exposure) including broad-spectrum solar radiation (approx. 122 nm to the near infrared). The organic films are enclosed in hermetically sealed sample cells that contain one of four astrobiologically relevant microenvironments. Transmission spectra (200-1000 nm) were recorded for each film, at first daily and subsequently every 15 days, along with a solar spectrum and the dark response of the detector array. In addition to analysis via UV-Vis spectroscopy, the laboratory controls were also monitored via infrared and far-UV spectroscopy. The results presented will include the finding that the FeTPPCI and IVA organic films in contact with a humid headspace gas (0.8-2.3%) exhibit faster degradation times, upon irradiation, in comparison with identical films under dry headspaces gases, whereas the Anth thin film exhibited a higher degree of photostability. In the companion laboratory experiments, simulated solar exposure of FeTPI films in contact with either Ar or CO(sub -2):O(sub -2):Ar (10:0.01:1000) headspace gas results in growth of a band in the films infrared spectra at 1961 cm(sup 1). Our assignment of this new spectral feature and the corresponding rational will be presented. The relevance of O/OREOS findings to planetary science, biomarker research, and the photostability of organic materials in astrobiologically relevant environments will also be discussed.

https://ntrs.nasa.gov/api/citations/20140006934/downloads/20140006934.pdf

Organism/Organic Exposure to Orbital Stresses (OOREOS) Satellite: Radiation Exposure in LEO and Supporting Laboratory Studies

Resolved profiles of diffuse interstellar bands : evidence for rotational contours of gas-phase molecules

We give an update on the data analysis relevant to Mars geology at multiple scales from a series of field research campaigns (ILEWG EuroMoonMars) in the extreme environment of the Utah desert and in order to help in the interpretation of Mars missions measurements from orbit (Mars Express, MRO) or from the surface (MSL Curiosity) at Gale crater. ILEWG EuroMoonMars campaigns The goal of this ILEWG EuroMoonMars project (February 23rd March 9th, 2013) was to conduct field studies in order to identify and study environments that are analogous to those that Curiosity has studied and will study at Gale crater. Several field campaigns (EuroGeoMars2009 and DOMMEX/ILEWG EuroMoonMars from November 2009 to March 2010) had been conducted at the Mars Desert Research Station (MDRS) [1-5] near Hanksville, Utah, in the vicinity of the San Rafael swell.. Geology traverse planning using sub-m imagery Most of the information we have from Moon and Mars surface, comes from satellite observations. During the selection of landing sites and planning of traverses on unfamiliar planetary sites, satellite images of high resolution is crucial. But what information are we missing from these images? We used remote sensing images and multispectral data to recognize areas of intrest (Figs 1-2). During ILEWG EuroMoonMars 2013 campaign at MDRS Utah we made a comparative study where we looked at satellite images with a spatial resolution of 50-60 cm per pixel, something that is comparable to the resolution of MRO HiRise on Mars. We then planned traverses at MDRS that were as similar to geomorphological features seen at the Gale crater as possible. Following this, we explored these traverses with a rover, drone and walked them in a Mars EVA simulation mode, before taking rocks and soil samples. We also tested the usability of a drone for imaging reconnaissance, and assessed experiences and lessons learnt concerning geological traverse planning based on high resolution satellite images. Figure 1: Map of geological features and inverted riverbeds around MDRS, Utah showing areas explored by traverses and EVAs, and through samples. Figure 2 : Landsat multispectral data show the presence of calcite (pink color) along the inverted channels. 1462.pdf Eighth International Conference on Mars (2014)

Gale Crater Analogue Geology Studies at Multiple Scales

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