748 research outputs found

    Martian seismicity through time from surface faulting

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    An objective of future Mars missions involves emplacing a seismic network on Mars to determine the internal structure of the planet. An argument based on the relative geologic histories of the terrestrial planets suggests that Mars should be seismically more active than the Moon, but less active than the Earth. The seismicity is estimated which is expected on Mars through time from slip on faults visible on the planets surface. These estimates of martian seismicity must be considered a lower limit as only structures produced by shear faulting visible at the surface today are included (i.e., no provision is made for buried structures or non-shear structures); in addition, the estimate does not include seismic events that do not produce surface displacement (e.g., activity associated with hidden faults, deep lithospheric processes or volcanism) or events produced by tidal triggering or meteorite impacts. Calibration of these estimates suggests that Mars may be many times more seismically active than the Moon

    An Optical Study of 3C 31, 3C 66B, 3C 120, and Their Jets

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    Paper freely available at http://cdsads.u-strasbg.fr/cgi-bin/nph-iarticle_query?1991AJ....102..562F&data_type=PDF_HIGH&type=PRINTERWe present the results of BVRI CCD photometry of the radiogalaxies 3C 31, 3C 66B, and 3C 120, and V polarimetry of 3C 120. The photometry of the jet of 3C 66B definitively establishes the synchrotron nature of the optical emission. No optical counterpart of the radio counterjet in 3C 66B and of the radio jets in 3C 31 and 3C 120 is found. A rotating ring and an ionized region are present respectively in 3C 31 (NGC 383) and its companion galaxy NGC 382, but we find no isophotal distortions which could have revealed a gravitational interaction between the two galaxies as it is the case in 3C 66B. The elliptical isophotes of 3C 120 shows a slight off-centering, roughly in the direction of the radio jet, very much like 3C 66B. We find an upper limit of 20% for the polarization level of the condensations in 3C 120

    Present-day Mars' seismicity predicted from 3-D thermal evolution models of interior dynamics

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    ©2018. American Geophysical UnionThe Interior Exploration using Seismic Investigations, Geodesy and Heat Transport mission, to be launched in 2018, will perform a comprehensive geophysical investigation of Mars in situ. The Seismic Experiment for Interior Structure package aims to detect global and regional seismic events and in turn offer constraints on core size, crustal thickness, and core, mantle, and crustal composition. In this study, we estimate the present‐day amount and distribution of seismicity using 3‐D numerical thermal evolution models of Mars, taking into account contributions from convective stresses as well as from stresses associated with cooling and planetary contraction. Defining the seismogenic lithosphere by an isotherm and assuming two end‐member cases of 573 K and the 1073 K, we determine the seismogenic lithosphere thickness. Assuming a seismic efficiency between 0.025 and 1, this thickness is used to estimate the total annual seismic moment budget, and our models show values between 5.7 × 1016 and 3.9 × 1019 Nm

    Effect of soil temperature on vegetative and reproductive growth and development in three spanish genotypes of peanut (Arachis hypogaea L.)

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    Extremes of soil temperature limit yield development of peanut. To obtain information relevant to improving yield by agronomic management and breeding, the influence of the soil temperature regimes (day/night) of 20/14 (Tl), 26/20 (T2), 32/26 (T3), and 38/32 C (T4) imposed from the time of peg penetration into the soil until maturity on growth and development of three Spanish genotypes of peanut (Arachis hypogaea L.) was investigated in a greenhouse..

    Effect of separate pod and root zone temperatures on yield and seed composition of three Spanish cultivars of groundnut (Arachis hypogaea L)

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    The effect of separate pod and root temperature regimes (all four combinations of 28/22 and 40/34 °C day/night temperature), imposed from the time of peg penetration until harvest, on yield and seed composition of three Spanish genotypes of groundnut (Arachis hypogaea L) was investigated. A decrease in pod temperature from 40/34 to 28/22 °C increased yield and oil, starch and protein mass per plant irrespective of root temperature. Additionally, a reduction in pod temperature decreased protein concentration and increased the sum of oil and starch concentration at a root temperature of 28/22 °C, whereas at a root temperature of 40/34 °C a decrease in pod temperature increased protein concentration. Root temperature reduction diminished oil concentration of genotypes AH 6179 and TMV 2 at a pod temperature of 40/34 °C. A decline in pod temperature affected fatty acid composition through a decrease in palmitic acid irrespective of root temperature and an increase in linoleic acid at a root temperature of 28/22 °C. A root temperature effect on fatty acid composition was not detected. It is concluded that field management practices and choice of genotype can influence groundnut yield and seed composition through effects on pod and root temperatur

    Sleep diplomacy: an approach to boosting global brain health

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    Sleep diplomacy highlights the urgent need to address the widespread issue of sleep deprivation and its detrimental effects on overall health, particularly brain health and healthy ageing. By providing practical advice on sleep hygiene, healthy schedules, and light exposure, sleep diplomacy aims to promote a comprehensive approach to well-being. Despite the well-established importance of sleep for optimal cognitive function, emotional regulation, and physical abilities, it is often neglected in public and medical recommendations.Our proposed concept of sleep diplomacy also offers practical recommendations to address sleep issues in various settings and populations.Fil: Golombek, Diego Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de San Andrés; ArgentinaFil: Booi, Laura. Leeds Beckett University; Reino Unido. Trinity College; IrlandaFil: Campbell, Dominic. Trinity College; IrlandaFil: Dawson, Walter D. Trinity College; Irlanda. University of California; Estados Unidos. Global Brain Health Institute; Estados Unidos. Oregon Health and Science University; Estados Unidos. Portland State University; Estados UnidosFil: Eyre, Harris. Rice University; Estados Unidos. University of California; Estados UnidosFil: Lawlor, Brian. Trinity College; IrlandaFil: Ibañez, Agustin Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de San Andrés; Argentina. Trinity College; Irlanda. University of California; Estados Unidos. Global Brain Health Institute; Estados Unidos. Universidad Adolfo Ibañez; Chil

    A Technique for Imposing Separate Temperature Regimes on Pods and Roots of Peanut (Arachis hypogaea L.)

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    Recent studies have shown marked effects of soil temperature on growth, development, and seed composition of peanut. Knowledge about how soil temperature affects pods and roots separately could provide useful information for field management and genetic manipulation. To facilitate such investigations, a technique was developed which allows imposition of different temperature regimes to the pods and the roots separately. Pods and roots were grown in different compartments that have soil temperature controlled by separate water baths. Day/night temperature regimes of 28/22 and 40/34 C with a 12-hr ‘day’ and 12-hr ‘night’ period were imposed to the pod and root compartments separately in all four possible combinations of these temperature regimes. The temperature change between the ‘day’ and ‘night’ period occured mainly within the first 2 brand the transition to tbe final temperature required up to 5 hr. After adjustment to the ‘day’ or ‘night’ temperatures, the temperatures ranged in the 40/34 C treatment between the programmed temperature and 0.6 C less (root compartments) or 0.8 C less (pod compartments); and the maximal fluctuation in the 28/22 C treatment is ± 0.3 C (root compartments) or ± 0.6 C (pod compartments

    Geology of McLaughlin Crater, Mars: A Unique Lacustrine Setting with Implications for Astrobiology

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    McLaughlin crater is a 92-kmdiameter Martian impact crater that contained an ancient carbonate- and clay mineral-bearing lake in the Late Noachian. Detailed analysis of the geology within this crater reveals a complex history with important implications for astrobiology [1]. The basin contains evidence for, among other deposits, hydrothermally altered rocks, delta deposits, deep water (>400 m) sediments, and potentially turbidites. The geology of this basin stands in stark contrast to that of some ancient basins that contain evidence for transient aqueous processes and airfall sediments (e.g. Gale Crater [2-3])
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