scholarly journals Effects of Vertical Nonlinearity on the Superconducting Gravimeter CT #036 at Ishigakijima, Japan

2021 ◽  
Author(s):  
Yuichi Imanishi ◽  
Kazunari Nawa ◽  
Yoshiaki Tamura ◽  
Hiroshi Ikeda
Keyword(s):  
Vertical Component ◽  
Superconducting Gravimeter ◽  
Slow Slip Events ◽  
High Background ◽  
Gravity Sensor ◽  
High Background Noise ◽  
Experimental Approaches ◽  
Characteristic Features ◽  
The Times

Abstract One of the characteristic features of the gravity recordings produced by the superconducting gravimeter CT #036 at Ishigakijima, Japan, is that it indicates gravity increase when a typhoon (hurricane) approaches the island. Since we are trying to detect small gravity signals associated with the long-term slow slip events in this region, it is very important in the interpretation of the observed data whether such gravity changes are of natural or instrumental origin. In this paper, we investigate whether or not nonlinearity in the sensor of the superconducting gravimeter is responsible for this phenomenon. Here we take the same theoretical approach as taken by Imanishi et al. (2018) which investigated the effect of coupling between horizontal and vertical components of the gravity sensor in order to understand the noise caused by the movements of a nearby VLBI antenna. From theoretical and experimental approaches, we prove that the gravity increase observed by CT #036 at the times of high background noise level can not be explained by instrumental effects such as the nonlinearity in the vertical component or the coupling between horizontal and vertical components of the gravity sensor. This implies that the observed gravity increases are real gravity signals of natural origin.

scholarly journals Hydrological Signals in Tilt and Gravity Residuals at Conrad Observatory (Austria)

2020 ◽  
Author(s):  
Bruno Meurers ◽  
Gábor Papp ◽  
Hannu Ruotsalainen ◽  
Judit Benedek ◽  
Roman Leonhardt
Keyword(s):  
Vertical Component ◽  
Gravitational Effect ◽  
Heavy Rain ◽  
Superconducting Gravimeter ◽  
Gravity Potential ◽  
Hydrological Process ◽  
Wide Range ◽  
Site Water ◽  
Set Up

Abstract. The Superconducting Gravimeter GWR C025 monitors the vertical component of the gravity vector at the Conrad Observatory (Austria) since autumn 2007. Two tilt meters operate continuously since spring 2016: a 5.5 m long interferometric water level tilt meter and a Lippmann-type 2D pendulum tilt sensor. The co-located and co-oriented set up enables a wide range of investigations because tilts are sensitive both to geometrical solid Earth deformations and to gravity potential changes. The tide free residuals of the SG and both tilt meters clearly reflect the gravity/deformation effects associated with short- and long-term environmental processes and reveal a complex water transport process at the observatory site. Water accumulation on the terrain surface causes short-term (a few hours) effects which are clearly imaged by the SG gravity and N-S tilt residuals. Long-term (> a few days/weeks) tilt and gravity variations occur frequently after long-lasting rain, heavy rain or rapid snowmelt. Gravity and tilt residuals are associated to the same hydrological process but have different physical causes. SG gravity residuals reveal the gravitational effect of water mass transport, while modelling results exclude a purely gravitational source of the observed tilts. Tilt residuals show the response on surface loading instead. N-S tilt signals are much stronger than those of the E-W component most probably due to the well-known cavity effect of the 150 m long tunnel oriented in E-W direction.

Effects of Classroom Noise on Students and Teachers in Greece

2003 ◽  
Vol 96 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Dimitris Skarlatos ◽  
Manolis Manatakis
Keyword(s):  
High School ◽  
Background Noise ◽  
Reverberation Time ◽  
Noise Levels ◽  
High Background ◽  
High Noise ◽  
Significant Percentage ◽  
Time Period ◽  
High Background Noise

Measurements inside 32 occupied high-school classrooms during the courses showed that the measured long-term equivalent noise levels are high. A significant percentage of students and teachers found these levels unacceptable. The observed noise levels depend on the time period of the course, the age, and the number of the students in each classroom. The large reverberation time and the high background noise are responsible for the measured high noise level.

scholarly journals Hair Cortisol Concentration as a Biomarker of Sleep Quality and Related Disorders

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 81
Author(s):  
Nisrin El Mlili ◽  
Hanan Ahabrach ◽  
Omar Cauli
Keyword(s):  
Sleep Disorders ◽  
Reference Ranges ◽  
Hair Cortisol ◽  
Neuropsychiatric Diseases ◽  
Close Relationship ◽  
Adults And Children ◽  
Experimental Approaches ◽  
Common Manifestation ◽  
Functional Alteration

Cortisol is the end product of the hypothalamic-pituitary-adrenal (HPA) axis, and its production is increased mainly in stressful situations or in chronic disorders accompanied by stress enhancement. Altered cortisol concentrations have been reported in a number of neuropsychiatric diseases and sleep disorders. Cortisol concentrations have been measured using several methods, and in several matrixes, such as blood, saliva, and urine. However, lately, hair cortisol, for several reasons, has emerged as a promising biomarker of long-term retrospective HPA activation. Several experimental approaches for cortisol measurement with the corresponding concentration reference ranges and a summary of findings from scientific literature on this field are presented. There is evidence of a close relationship between HPA functional alteration and the development of neuropsychiatric disorders. Sleep disorders are the most common manifestation in several neuropsychiatric conditions, and have also been associated to cortisol alterations in both adults and children. Many studies indicate that hair cortisol constitutes a valuable tool for further contributing to existing data on salivary, plasma, or urinary cortisol concentrations in patients with sleep disorders.

scholarly journals CCD Observations and Analysis of the W UMA Type Binary SS Arietis

1998 ◽  
Vol 11 (1) ◽  
pp. 382-382
Author(s):  
Wonyong Han ◽  
Chun-Hwey Kim ◽  
Jae Woo Lee ◽  
Ho-Il Kim ◽  
Woo-Baik Lee
Keyword(s):  
Period Change ◽  
Light Curves ◽  
Period Variation ◽  
Light Elements ◽  
Astronomy Observatory ◽  
Third Body ◽  
Convective Envelope ◽  
Ccd Observations ◽  
The Times

The BVR CCD observations of W UMa-type eclipsing binary SS Arietis were made for ten nights from November 1996 to December 1996 at the Sobaeksan Astronomy Observatory. From the observed light curves, nine new times of minimum lights were derived from the Kwee and van Woerden’s method. Improved light elements for this system were determined from these minimum lights with all the published minima. The analysis of the times of minima of SS Ari confirms that the orbital period of SS Ari has been suffering from a sinusoidal variation as the suggestions of other previous investigators (Kaluzny & Pojmanski 1984, Demircan & Selam 1993). The calculation shows that the cyclic period change has a period of about 56.3yrs with an amplitude of about 0.d052. The period variation has been discussed in terms of two potential mechanisms: 1) the light-time effect due to a hypothetical third body and 2) deformations in the convective envelope of a magnetically active component. The BVR light curves of SS Ari observed for about one month showed the existence of cycle to cycle light variations. Long-term light changes of SS Ari are discussed in terms of the period variation of the binary system.

Pleistocene–Holocene environmental change in the Canary Archipelago as inferred from the stable isotope composition of land snail shells

2011 ◽  
Vol 75 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Yurena Yanes ◽  
Crayton J. Yapp ◽  
Miguel Ibáñez ◽  
María R. Alonso ◽  
Julio De-la-Nuez ◽  
...  
Keyword(s):  
Environmental Change ◽  
Canary Islands ◽  
Environmental Changes ◽  
Isotope Composition ◽  
Moving Average ◽  
Land Snail ◽  
Balance Model ◽  
Low Latitude ◽  
The Times

AbstractThe isotopic composition of land snail shells was analyzed to investigate environmental changes in the eastern Canary Islands (28–29°N) over the last ~ 50 ka. Shell δ13C values range from −8.9‰ to 3.8‰. At various times during the glacial interval (~ 15 to ~ 50 ka), moving average shell δ13C values were 3‰ higher than today, suggesting a larger proportion of C4 plants at those periods. Shell δ18O values range from −1.9‰ to 4.5‰, with moving average δ18O values exhibiting a noisy but long-term increase from 0.1‰ at ~ 50 ka to 1.6–1.8‰ during the LGM (~ 15–22 ka). Subsequently, the moving average δ18O values range from 0.0‰ at ~ 12 ka to 0.9‰ at present. Calculations using a published snail flux balance model for δ18O, constrained by regional temperatures and ocean δ18O values, suggest that relative humidity at the times of snail activity fluctuated but exhibited a long-term decline over the last ~ 50 ka, eventually resulting in the current semiarid conditions of the eastern Canary Islands (consistent with the aridification process in the nearby Sahara). Thus, low-latitude oceanic island land snail shells may be isotopic archives of glacial to interglacial and tropical/subtropical environmental change.

scholarly journals Automatic synchronisation of the cell cycle in budding yeast through closed-loop feedback control

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Giansimone Perrino ◽  
Sara Napolitano ◽  
Francesca Galdi ◽  
Antonella La Regina ◽  
Davide Fiore ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Autonomous Vehicles ◽  
Genetic System ◽  
Yeast Cells ◽  
Control Engineering ◽  
Loop Feedback ◽  
Experimental Approaches ◽  
Closed Loop Feedback ◽  
Theoretical Foundations

AbstractThe cell cycle is the process by which eukaryotic cells replicate. Yeast cells cycle asynchronously with each cell in the population budding at a different time. Although there are several experimental approaches to synchronise cells, these usually work only in the short-term. Here, we build a cyber-genetic system to achieve long-term synchronisation of the cell population, by interfacing genetically modified yeast cells with a computer by means of microfluidics to dynamically change medium, and a microscope to estimate cell cycle phases of individual cells. The computer implements a controller algorithm to decide when, and for how long, to change the growth medium to synchronise the cell-cycle across the population. Our work builds upon solid theoretical foundations provided by Control Engineering. In addition to providing an avenue for yeast cell cycle synchronisation, our work shows that control engineering can be used to automatically steer complex biological processes towards desired behaviours similarly to what is currently done with robots and autonomous vehicles.

One-year long common view measurements with continuous gravimeters

2021 ◽  
Author(s):  
Franck Pereira Dos Santos ◽  
Pierre Vermeulen ◽  
Sylvain Bonvalot ◽  
Germinal Gabalda ◽  
Nicolas Le Moigne ◽  
...  
Keyword(s):  
Geodetic Network ◽  
Cold Atom ◽  
Superconducting Gravimeter ◽  
Common View ◽  
Long Term Stability ◽  
Earth Gravity ◽  
Measurement Session ◽  
One Year ◽  
Metrological Evaluation

<p>Since a few years, several laboratories, institutes or organizations through the world have acquired marketed quantum absolute gravimeters AQG developed by Muquans. Among their potentialities, these new generations of instruments are expected to complement the existing capabilities of long term monitoring of the Earth gravity field. A metrological evaluation of their performances for long-term measurements is thus a first step.</p><p>The LNE-SYRTE gravimetry laboratory in the suburb of Paris, has been designed to accommodate other gravimeters for metrological comparisons, tests and calibrations. Instruments of different classes operate in this well characterized laboratory: a laboratory-based absolute cold atom gravimeter (CAG) and a relative superconducting gravimeter iGrav. Both instruments allow for continuous measurements, Accuracy is guaranteed by the CAG and long-term stability by the iGrav.</p><p>We there have performed a more than one-year long measurement session with the initial version of the marketed quantum gravimeter AQG (AQG-A01).</p><p>An improved version of this AQG (AQG-B01) designed for outdoor measurement and recently acquired by RESIF (the French Seismologic and Geodetic Network) has been also implemented to close this session with a last month of simultaneous data recording involving all the instruments. Finally, we also performed supplementary accuracy tests, in particular to evaluate the Coriolis bias of the two AQG commercial sensors.</p><p>The talk will briefly present the different instruments to rapidly focus on the performances of the AQGs and results of the comparisons.</p>

scholarly journals Dedifferentiated liposarcoma of the retroperitoneum with osteosarcomatous component

2012 ◽  
Vol 2 (2) ◽  
pp. 33 ◽  
Author(s):  
Wenbin Sun ◽  
Xiaoyan Sun ◽  
Dianbo Cao
Keyword(s):  
Adipose Tissue ◽  
Soft Tissue Sarcomas ◽  
Dedifferentiated Liposarcoma ◽  
Pathological Findings ◽  
Specific Tumor ◽  
Complete Surgical Resection ◽  
Calcified Tissue ◽  
Term Evaluation ◽  
Characteristic Features

Liposarcoma is one of the most common soft-tissue sarcomas and classified as five groups. Dedifferentiated liposarcoma includes multiple elements such as solid tissue, adipose tissue and calcified tissue, which is different from common liposarcoma in tissue constitue. Dedifferentiation to osteosarcoma is rarely described in the literature. We reported the radiological and pathological findings in a case of dedifferentiated liposarcoma with osteo-sarcomatous dedifferentiation in the retroperitoneum and discussed the characteristic features of this specific tumor. Complete surgical resection of the neoplasm is the only curative means, but establishing a prognosis remains a challenge for long-term evaluation.

scholarly journals Cyber-yeast: Automatic synchronisation of the cell cycle in budding yeast through closed-loop feedback control

2020 ◽  
Author(s):  
Giansimone Perrino ◽  
Sara Napolitano ◽  
Francesca Galdi ◽  
Antonella La Regina ◽  
Davide Fiore ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Autonomous Vehicles ◽  
Genetic System ◽  
Yeast Cells ◽  
Control Engineering ◽  
Loop Feedback ◽  
Experimental Approaches ◽  
Closed Loop Feedback ◽  
Theoretical Foundations

ABSTRACTThe cell cycle is the process by which eukaryotic cells replicate. Yeast cells cycle asynchronously with each cell in the population budding at a different time. Although there are several experimental approaches to “synchronise” cells, these work only in the short-term. Here, we built a cyber-genetic system to achieve long-term synchronisation of the cell population, by interfacing genetically modified yeast cells with a computer by means of microfluidics to dynamically change medium, and a microscope to estimate cell cycle phases of individual cells. The computer implements a “controller” algorithm to decide when, and for how long, to change the growth medium to synchronise the cell-cycle across the population. Our work builds upon solid theoretical foundations provided by Control Engineering. In addition to providing a new avenue for yeast cell cycle synchronisation, our work shows that computers can automatically steer complex biological processes towards desired behaviours similarly to what is currently done with robots and autonomous vehicles.

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