875 research outputs found

    Letter from R. B. Marshal to John Muir, 1913 Jul 19.

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    PersonalWashington, D. C., July 19, 1913.Mr. John Muir,Martinez, California.My dear Mr. Muir: Mrs. Marshall has just written of the great joy yougave them all by your visit to Inverness--her only complaintwas that you could not stay longer. I know full well thegenuine pleasure you gave all, and especially the threeMarshall girls who love and admire you to the full measureof their lovable selves. I envied them to the limit – Iwas lonesome. John Muir is nine; for with all of his numerousfriends and admirers, I am positive no one in the world has or ever will feel the same deep bond of sympathetic affection foryou that I do.With this absolutely honest statement, you can imaginemy feeling of pain when Mrs. Marshall informed me that youeven for a moment questioned my loyalty regarding the HetchHetchy matter. I did not appear before the Committee. Ihave taken no action whatever, for to do so would, no doubt,cost me my position, which I can\u27t afford to give up; I must05497 John Muir -- 2,control my feelings and actions for the sake of my threegirls. If I could afford to do so, I would give up myposition and fight to retain Hetch Hetchy Valley as a parkto an extent that would startle even you. and I honestly believe I would win, hut as I said above my mouth is gagged under present conditions.Therefore, for all time, please know that Marshallwill stand fire now and forever; he is honored by being onthe side with his good friend Muir, and even if Muir himselfShould agree to destroy the wonderfully beautiful HetchHetchy Valley by creating a lake for supplying power to San Francisco, Marshall would cross swords with him, his dearestfriend, and would fight to the last ounce of his ability. Can I state my position stronger or clearer?This letter is personal to you, Mr. Muir, and Iask you, please, to never again suspect my loyalty to thecause, no matter how or from whom you may get your information.I regret more than I can say that I can not, for financialreasons, remove the gag that my official position compelsme to respect. It is one of the greatest trials I have had inlife to keep still when the battle is on; under cover of05497 John Muir -- 3.darkness when if the enemy were forced into the light theywould he routed for all time by the first charge.Again assuring you of my utmost loyalty and desireto save Hetch Hetchy Valley as nature gave it to us, and ofmy love and respect for you, I remainMost sincerely yours,[illegible]0549

    "Daños remotos", "Peligro abstracto" y los "Dos Principios del Daño"

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    Los debates sobre la aplicación, las implicancias y la utilidad del "Principio del Daño" están generalmente viciadas por el hecho de no dar cuenta de que en realidad hay dos Principios del Daño distintos, o así argumentaremos. Después de distinguir ambos principios en la Sección 1, y de mostrar cómo generan diferentes resultados, en virtud de sus diferentes estructuras lógicas, mostramos en la Sección 2 una de estas formulaciones hace problemática la criminalización de los "daños remotos" y del llamado "peligro abstracto". Sin embargo, con base en el otro Principio del Daño, podemos resolver (en realidad, disolver) estos problemas, como veremos en la sección 3

    Regulated Formation of an Amyloid-like Translational Repressor Governs Gametogenesis

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    Message-specific translational control is required for gametogenesis. In yeast, the RNA-binding protein Rim4 mediates translational repression of numerous mRNAs, including the B-type cyclin CLB3, which is essential for establishing the meiotic chromosome segregation pattern. Here, we show that Rim4 forms amyloid-like aggregates and that it is the amyloid-like form of Rim4 that is the active, translationally repressive form of the protein. Our data further show that Rim4 aggregation is a developmentally regulated process. Starvation induces the conversion of monomeric Rim4 into amyloid-like aggregates, thereby activating the protein to bring about repression of translation. At the onset of meiosis II, Rim4 aggregates are abruptly degraded allowing translation to commence. Although amyloids are best known for their role in the etiology of diseases such as Alzheimer’s, Parkinson’s, and diabetes by forming toxic protein aggregates, our findings show that cells can utilize amyloid-like protein aggregates to function as central regulators of gametogenesis.Charles A. King Trust (Postdoctoral Fellowship)American Cancer Society (Fellowship)National Institutes of Health (U.S.) (Grants GM62207, GM77537, and GM094303

    Lanthanum staining of coronary microvascular endothelium: Effects of ischemia reperfusion, propranolol, and atenolol

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    Cat isolated hearts were perfused via the aorta with normothermic arterial blood from donor cats. After 1 hr of equilibration, dl-propranolol (1.9 mg/kg), atenolol (1.65 mg/kg), or physiological saline solution was infused via the aortic cannula. The hearts were made globally ischemic for 1 hr and reperfused for 1 hr. Hearts given saline but not made ischemic, and hearts from blood-donor cats served as controls. The hearts were flushed with physiological saline for 2 min, then perfused with cacodylate-buffered glutaraldehyde containing 1% LaCl3. Samples of left ventricle were postfixed in osmium and prepared for electron microscopy. Microvessels in nonischemic tissues had heavy La3+ staining on luminal surfaces of endothelial cells. Many plasmalemmal vesicles along luminal surfaces of endothelial cells were filled with La3+. Several vesicles appeared to open onto both surfaces thus forming channels through the endothelium. Lanthanum penetrated into, and occasionally through, interendothelial junctions. Endothelial cells lining vessels in ischemic myocardium were swollen, had pale cytoplasm, and showed little La3+ on the luminal surfaces. Few plasmalemmal vesicles were present and the mitochondria contained deposits of La3+. Extravascular spaces were distended but interendothelial junctions seemed to be intact. Lanthanum staining and morphology of endothelial cells in hearts treated with propranolol or atenolol were very similar to nonischemic myocardium. The data suggest that the [beta]-blocking agents, propranolol and atenolol, maintain the integrity of coronary vascular endothelium during ischemia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24387/1/0000657.pd

    Time-dependent changes in canine cardiac mitochondrial function and ultrastructure resulting from coronary occlusion and reperfusion

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    Time-dependent changes in mitochondrial function and structure resulting from 1 hr of left circumflex coronary artery occlusion followed by 2 to 24 hrs of reperfusion were examined. These changes were correlated with changes in myocardial ultrastructure, tissue water content, infarct size and mitochondrial calcium content. The heart was removed after different periods of reperfusion, and mitochondria were isolated from ischemic and nonischemic regions of the left ventricle. Tissue samples from ischemic and nonischemic myocardium also were taken for electron microscopy and tissue water content determinations. Infarct size was measured by the nitroblue tetrazolium staining method. Oxygen consumption by mitochondria isolated from ischemic and nonischemic myocardium was measured in vitro . Mitochondria from ischemic myocardium showed time-dependent decreases in rates of oxygen consumption and tightness of coupling. Electron microscopy revealed progressive ultrastructural deterioration in ischemic myocardium, including accumulation of calcium deposits within mitochondria, a finding corroborated by elevated concentrations of calcium in mitochondria isolated from the same area. Tissue wet-to-dry weight ratios were increased significantly in ischemic myocardium. A small, but significant, decrease in respiratory function was observed in mitochondria isolated from nonischemic myocardium several hrs after reperfusion; however, nomal respiration was observed 24 hrs after release of occlusion. This latter observation indicates that the nonischemic zone also is affected by regional ischemia. The results obtained indicate that temporary left circumflex artery occlusion and reperfusion result in progressively decreasing mitochondrial function and structure within the ischemic myocardium, and that these changes are accompanied by cellular electrolyte alterations. Untersucht wurden zeitabhängige Veränderungen in Struktur und Funktion der Mitochondrien, die durch einstündigen Verschluß und 2- bis 24stündige Reperfusion des Ramus circumflexus der linken Koronararterie erzeugt wurden. Diese Veränderungen wurden mit Veränderungen der myokardialen Ultrastruktur, dem Wassergehalt des Gewebes, der Infarktgröße und dem mitochondrialen Calciumgehalt korreliert. Das Herz wurde nach verschiedenen Reperfusionszeiten entnommen und die Mitochondrien aus ischämischen und nichtischämischen Gebieten des linken Ventrikels isoliert. Ebenso wurden Gewebeproben von ischämischem und nichtischämischem Myokard für Elektronenmikroskopie und Bestimmung des Wassergehaltes des Gewebes entnommen. Die Infarktgröße wurde durch die Anfärbung mit Nitroblau-Tetrazolium bestimmt. Der Sauerstoffverbrauch der Mitochondrien aus ischämischem und nichtischämischem Myokard wurde in vitro gemessen. Mitochondrien aus ischämischem Myokard zeigten eine zeitabhängige Abnahme des Sauerstoffverbrauchs und seiner Bindung an die Phosphorylierung von ADP. Die Elektronenmikroskopie zeigte eine fortschreitende Zerstörung der Ultrastruktur im ischämischen Myokard, einschließlich einer Zunahme der Calciumablagerungen in Mitochondrien, was mit erhöhten Calciumkonzentrationen in Mitochondrien aus dem gleichen Gebiet übereinstimmte. Im ischämischen Myokard war die Relation Feuchtgewicht/Trockengewicht signifikant erhöht. Eine geringe, aber signifikante Abnahme der Atmung wurde in Mitochondrien, die nach einigen Stunden Reperfusion aus nichtischämischem Myokard isoliert worden waren, beobachtet; aber nach 24 h Reperfusion fand sich normale Atmung. Letzteres weist darauf hin, daß auch das nichtischämische Gebiet von der regionalen Ischämie betroffen ist. Die Ergebnisse zeigen, daß vorübergehender Verschluß des Ramus circumflexus der linken Koronararterie und Reperfusion zu fortschreitender Zerstörung mitochondrialer Funktion und Struktur führen und daß diese Veränderungen von Änderungen des Electrolytstatus der Zelle begleitet werden.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41744/1/395_2005_Article_BF01907837.pd

    Coping Skills and Parent Support Mediate the Association Between Childhood Attention-Deficit/Hyperactivity Disorder and Adolescent Cigarette Use

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    To examine mediators of the association between childhood attention-deficit/hyperactivity disorder (ADHD) and adolescent cigarette use

    Mapping recent shoreline changes spanning the lateral collapse of Anak Krakatau Volcano, Indonesia

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    We use satellite imagery to investigate the shoreline changes associated with volcanic activity in 2018–2019 at Anak Krakatau, Indonesia, spanning a major lateral collapse and period of regrowth through explosive activity. The shoreline changes have been analyzed and validated through the adaptation of an existing methodology based on Sentinel-2 multispectral imagery and developed on Google Earth Engine. This work tests the results of this method in a highly dynamic volcanic environment and validates them with manually digitized shorelines. The analysis shows that the size of the Anak Krakatau Island increased from 2.84 km2 to 3.19 km2 during 15 May 2018–1 November 2019 despite the loss of area in the 22 December 2018 lateral collapse. The lateral collapse reduced the island area to ~1.5 km2 but this was followed by a rapid increase in area in the first two months of 2019, reaching up to 3.27 km2. This was followed by a period of little change as volcanic activity declined and then by a net decrease from May 2019 to 1 November 2019 that resulted from erosion on the SW side of the island. This history of post-collapse eruptive regrowth and coastal erosion derived from the shoreline changes illuminates the potential for satellite-based automated shoreline mapping to provide databases for monitoring remote island volcanoes

    The Nearby Evolved Stars Survey I. JCMT/SCUBA-2 Submillimeter Detection of the Detached Shell of U Antliae

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    We present the highest resolution single-dish submillimetre observations of the detached shell source U Antliae to date. The observations were obtained at 450 and 850m with SCUBA-2 instrument on the James Clerk Maxwell Telescope as part of the Nearby Evolved Stars Survey. The emission at 850m peaks at 40 arcsec with hints of a second peak seen at 20 arcsec. The emission can be traced out to a radius of 56 arcsec at a 3 level. The outer peak observed at 850m aligns well with the peak observed at Herschel/PACS wavelengths. With the help of spectral energy distribution fitting and radiative transfer calculations of multiple-shell models for the circumstellar envelope, we explore the various shell structures and the variation of grain sizes along the in the circumstellar envelope. We determine a total shell dust mass of (2.0 0.3) 105 M and established that the thermal pulse that gave rise to the detached shell occurred 3500 500 yr ago
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