scholarly journals Determining Mean and Standard Deviation of the Strong Gravity Prior through Simulations

2020 ◽  
Author(s):  
Björn Jörges ◽  
Joan López-Moliner
Keyword(s):  
Standard Deviation ◽  
Moving Objects ◽  
Sensory Information ◽  
Published Data ◽  
Timing Errors ◽  
Earth Gravity ◽  
The Earth ◽  
Timing Task ◽  
Best Fit ◽  
Different Sources

Humans expect downwards moving objects to accelerate and upwards moving objects to decelerate. These results have been interpreted as humans maintaining an internal model of gravity. We have previously suggested an interpretation of these results within a Bayesian framework of perception: earth gravity could be represented as a Strong Prior that overrules noisy sensory information (Likelihood) and therefore attracts the final percept (Posterior) very strongly. Based on this framework, we use published data from a timing task involving gravitational motion to determine the mean and the standard deviation of the Strong Earth Gravity Prior. To get its mean, we refine a model of mean timing errors we proposed in a previous paper (Björn Jörges & López-Moliner, 2019), while expands the range of conditions under which it yields adequate predictions of performance. This underscores our previous conclusion that the gravity prior is likely to be very close to 9.81 m/s². To obtain the standard deviation, we identify different sources of sensory and motor variability reflected in timing errors. We then model timing responses based on quantitative assumptions about these sensory and motor errors for a range of standard deviations of the earth gravity prior, and find that a standard deviation of around 2 m/s² makes for the best fit. This value is likely to represent an upper bound, as there are strong theoretical reasons along with support empirical evidence for the standard deviation of the earth gravity being lower than this value.

scholarly journals Sequential modelling of the Earth’s core magnetic field

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Guillaume Ropp ◽  
Vincent Lesur ◽  
Julien Baerenzung ◽  
Matthias Holschneider
Keyword(s):  
Magnetic Field ◽  
Prior Information ◽  
Spatial Scales ◽  
Model Parameters ◽  
International Geomagnetic Reference Field ◽  
The Earth ◽  
Temporal And Spatial ◽  
Different Sources ◽  
Original Approach ◽  
Modelling Approach

Abstract We describe a new, original approach to the modelling of the Earth’s magnetic field. The overall objective of this study is to reliably render fast variations of the core field and its secular variation. This method combines a sequential modelling approach, a Kalman filter, and a correlation-based modelling step. Sources that most significantly contribute to the field measured at the surface of the Earth are modelled. Their separation is based on strong prior information on their spatial and temporal behaviours. We obtain a time series of model distributions which display behaviours similar to those of recent models based on more classic approaches, particularly at large temporal and spatial scales. Interesting new features and periodicities are visible in our models at smaller time and spatial scales. An important aspect of our method is to yield reliable error bars for all model parameters. These errors, however, are only as reliable as the description of the different sources and the prior information used are realistic. Finally, we used a slightly different version of our method to produce candidate models for the thirteenth edition of the International Geomagnetic Reference Field.

scholarly journals I. On a simple mode of eliminating errors of adjustment in delicate observations of compared spectra

1881 ◽  
Vol 31 (206-211) ◽  
pp. 470-473
Keyword(s):  
Radial Component ◽  
Simple Mode ◽  
The Earth ◽  
Different Sources

When the identity or difference of position of two lines, bright or dark, in the spectra of two lights from different sources has to be compared with the utmost degree of accuracy, they are admitted simultaneously into different but adjacent parts of the slit of a spectroscope and viewed together. It was thus, for instance, that Dr. Huggins proceeded in determining the radial component of the velocity of the heavenly bodies relatively to the earth. It is requisite that the two lights that are to be compared should fall in a perfectly similar manner on the s lit: and it will be seen, from a perusal of his paper, how careful Dr. Huggins was in this respect.

scholarly journals Radioactive and Non-Radioactive Element Analysis of Dorado Gas Discovery of Sri Lanka and Their Influence on Natural Environment

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
S.S.N. Gamage ◽  
R.M.T.S. Ratnayake ◽  
A.M.A.D.M. Senadhira ◽  
D.A. Weerasinghe ◽  
V.A. Waduge
Keyword(s):  
Sri Lanka ◽  
Gas Production ◽  
Gamma Ray Spectrometry ◽  
Published Data ◽  
Depth Range ◽  
Drilling Mud ◽  
Radioactive Elements ◽  
Drill Cuttings ◽  
The Earth ◽  
Oil Gas

Naturally-occurring radionuclides deposited beneath the earth, which are referred to as "NORM" and other toxicnon-radioactive elements transported to the earth surface with the oil and gas production. Hence, knowledge of the prevailing background levels of these elements in the subsurface reservoir formations is valuable to all stakeholders, most notably to regulatory authorities of the country. The drill cuttings obtained within depth range 3025m to 3095m of reservoir sand section in the deep water exploratory well (CLPL- Dorado 91 H/1z) drilled in the Mannar Basin offshore Sri Lanka were subjected to high-resolution Gamma-ray spectrometry and X-ray fluorescence (XRF) spectrometry.As test results revealed activity concentration of 40K varies from 0.338 Bq/g to 0.514 Bq/g, 210Pb from 0.007 Bq/g to 0.015 Bq/g, 226Ra from 0.012 Bq/g to 0.0145 Bq/g while 232Th levels are between 0.030 Bq/g to 0.040 Bq/g. According to the XRF testing levels of significantly hazardous non-radioactive elements are considerably lower, except for the level of the Barium. The Pb level varies between the 48 ppm to 22 ppm. The Thorium level varies between 9.6 ppm to 10.1 ppm. Manganese has a range of 5,173ppm to 653ppm.The barium levels are between 118,666 ppm to 24,400 ppm. NORM concentration of the tested section were on the lower side when results matched with the IAEA published data on NORM concentration in oil, gas and there byproducts and therefore there will be low level of NORM contaminations when the Dorado gas discovery proceeds to the production stage. Further there is no harmful public exposure from NORM by disposing these drill cuttings to environment or storing at any site location. But the disposal of the drilling mud and handling of the drilling mud should be conducted with cautious since extremely high Ba levels can potentially cause health problems.Keywords: NORM, drill-cuttings, oil, gas, Sri Lanka, XRF

‘Quit while you are ahead – and smell the roses!’ A survey of retired Fellows of the Australian and New Zealand College of Anaesthetists

2021 ◽  
pp. 0310057X2110057
Author(s):  
Diana Strange Khursandi ◽  
Victoria Eley
Keyword(s):  
Clinical Practice ◽  
New Zealand ◽  
Standard Deviation ◽  
Response Rate ◽  
Common Factors ◽  
Published Data ◽  
Factors Affecting ◽  
Retirement Decisions ◽  
Zealand College ◽  
The Mean

There are no published data on the age of retirement of anaesthetists in Australia and New Zealand. We surveyed 622 retired Fellows of the Australian and New Zealand College of Anaesthetists to determine their ages of complete retirement from clinical practice, demographics, and whether they had retired at the age they had intended to retire. We also aimed to explore factors affecting the decision to retire, the practice of ‘winding down’, common post-retirement activities, and the arrangement of personal and professional affairs. Responses were received from 371 specialists (response rate 60%). The mean (standard deviation) age of retirement was 65.2 (6.9) years. The mean (standard deviation) retirement ages ranged from 62.0 (7.1) years (those who retired earlier than planned) to 68.0 (4.3) years (those who retired later than they had intended). The mean (standard deviation) age of retirement of the male respondents was 66.0 (6.5) years, and for female respondents was 62.7 (7.7) years. Two hundred and thirty-three respondents (63%) reported winding down their practice prior to retirement, and 360 (97%) had made a will. Poor health and loss of confidence were the two most common factors in the retirement decisions of those who retired earlier than they had planned. Our results may assist current practitioners plan for retirement, and suggest strategies to help health services, departments and private groups accommodate individuals in winding down their practice.

scholarly journals Amplitude of Sunspot-Dependent Radiocarbon Variations: Data from Corals and Wine

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 111-115
Author(s):  
Mordeckai Magaritz ◽  
Israel Carmi ◽  
Ziv Sirkes
Keyword(s):  
Theoretical Analysis ◽  
Theoretical Calculation ◽  
Production Rate ◽  
Sunspot Cycle ◽  
Published Data ◽  
Earth Surface ◽  
The Earth ◽  
Surface System ◽  
Experimental Values

It has been suggested that the sunspot cycle modulates the production rate of radionuclides in the atmosphere and that these modulations can be traced in various parts of the earth surface system. On the basis of a theoretical analysis, Damon, Sternberg, and Radnell (1983) have concluded that the effects of the 11-yr cycle of sunspots should be observable in 14C data provided the measurements are done at a 2 permil (sd) level. This conclusion is based on calculations using models discussed by Lingenfelter and Ramaty (1970) and by O'Brien (1979) and on the 14C inventory modified from Damon, Lerman, and Long (1978). In this note we compare the amplitude estimate of Damon, Sternberg, and Radnell (1983), who calculated a representative peak-to-peak variation of 1.7‰ in 14C for the sunspot cycle between 1848 and 1856, with experimental values derived from recently published data. We find the experimental value to be larger by a significant factor from the theoretical calculation.

scholarly journals Space Debris – The Short Term Orbital Evolution in the Earth Gravity Field

1997 ◽  
Vol 165 ◽  
pp. 71-78
Author(s):  
Edwin Wnuk
Keyword(s):  
Space Debris ◽  
Orbital Evolution ◽  
Gravity Potential ◽  
Short Term ◽  
Near Earth Space ◽  
Earth Gravity ◽  
The Earth ◽  
Geopotential Models ◽  
Theory Of Motion

AbstractTwo aspects of the orbital evolution of space debris – the long-term evolution and the short-term one – are of interest for an exploration of the near- Earth space. The paper presents some results concerning the estimation of the accuracy of predicted positions of Earth-orbiting objects for the short-term: a few revolutions or a time-span interval of a few days. Calculations of predicted positions take into account the influence of an arbitrary number of spherical coefficients of the Earth gravity potential. Differences in predicted positions due to differences in the best contemporary geopotential models (JGM-2, JGM-3 and GRIM4-S4) are estimated with the use of an analytical theory of motion and a numerical integration.

scholarly journals The Antennal Pathway of Dragonfly Nymphs, from Sensilla to the Brain

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 886
Author(s):  
Silvana Piersanti ◽  
Manuela Rebora ◽  
Gianandrea Salerno ◽  
Sylvia Anton
Keyword(s):  
Brain Structure ◽  
Antennal Lobe ◽  
Sensory Information ◽  
Brain Structures ◽  
Brain Regions ◽  
Adult Brain ◽  
Published Data ◽  
Antennal Sensilla ◽  
Aquatic Life ◽  
The Brain

Dragonflies are hemimetabolous insects, switching from an aquatic life style as nymphs to aerial life as adults, confronted to different environmental cues. How sensory structures on the antennae and the brain regions processing the incoming information are adapted to the reception of fundamentally different sensory cues has not been investigated in hemimetabolous insects. Here we describe the antennal sensilla, the general brain structure, and the antennal sensory pathways in the last six nymphal instars of Libellula depressa, in comparison with earlier published data from adults, using scanning electron microscopy, and antennal receptor neuron and antennal lobe output neuron mass-tracing with tetramethylrhodamin. Brain structure was visualized with an anti-synapsin antibody. Differently from adults, the nymphal antennal flagellum harbors many mechanoreceptive sensilla, one olfactory, and two thermo-hygroreceptive sensilla at all investigated instars. The nymphal brain is very similar to the adult brain throughout development, despite the considerable differences in antennal sensilla and habitat. Like in adults, nymphal brains contain mushroom bodies lacking calyces and small aglomerular antennal lobes. Antennal fibers innervate the antennal lobe similar to adult brains and the gnathal ganglion more prominently than in adults. Similar brain structures are thus used in L. depressa nymphs and adults to process diverging sensory information.

MOCASS: A Satellite Mission Concept Using Cold Atom Interferometry for Measuring the Earth Gravity Field

2019 ◽  
Vol 40 (5) ◽  
pp. 1029-1053 ◽  
Author(s):  
Federica Migliaccio ◽  
Mirko Reguzzoni ◽  
Khulan Batsukh ◽  
Guglielmo Maria Tino ◽  
Gabriele Rosi ◽  
...  
Keyword(s):  
Gravity Field ◽  
Cold Atom ◽  
Atom Interferometry ◽  
Satellite Mission ◽  
Earth Gravity Field ◽  
Earth Gravity ◽  
The Earth

scholarly journals Athanasius Kircher and Terrestrial Magnetism: The Magnetic Map

2020 ◽  
Vol 7 (2) ◽  
pp. 166-184
Author(s):  
Agustín Udías, S.J.
Keyword(s):  
Magnetic Field ◽  
Terrestrial Magnetism ◽  
The Earth ◽  
Magnetic Declination ◽  
Athanasius Kircher ◽  
Different Sources ◽  
The Magnetic Field

Athanasius Kircher paid special attention to magnetism, more specifically terrestrial one, in his work Magnes sive de arte magnetica. Other Jesuits of his time, such as Garzoni and Cabeo, also wrote on this subject. Kircher studied in particular magnetic declination and its possible use to determine geographical longitudes. At his time, this was an important subject for long sea journeys. First, he collected a large number of observations of magnetic declination from different sources in three tables and two lists with a total of 518 values, among them forty-three made by Jesuits. Kircher proposed that a magnetic map could be made based on these observations, but he did not do it. From Kircher’s observations a map of magnetic declination has been drawn and it is presented here. Kircher discussed the causes of declination and presented a model for the origin of the magnetic field of the Earth, which differed from that proposed by Gilbert. Kircher finally considered magnetism as a cosmic force with its origin in God.

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