scholarly journals Estimation of free core resonance parameters based on long-term strain observations in the diurnal frequency band

2019 ◽  
pp. 41-50
Author(s):  
V. K. Milyukov ◽  
A. Amoruso ◽  
L. Crescentini ◽  
A. P. Mironov ◽  
A. V. Myasnikov ◽  
...  
Keyword(s):  
Laser Interferometer ◽  
Liquid Core ◽  
Resonant Mode ◽  
Parameter Estimates ◽  
Retrograde Motion ◽  
Tidal Waves ◽  
Superconducting Gravimeters ◽  
Fixed Reference ◽  
Free Core Resonance

The free core nutation (FCN) is one of the Earth’s rotational eigenmodes, which is caused by the retrograde motion of the liquid core relative to the mantle. The FCN period and Q-factor are determined by the elastic properties of the core/mantle boundary (CMB) and their electromagnetic interaction. In the celestial coordinate system, the FCN period is about 430 days; in the Earth-fixed reference frame this effect manifests itself in the form of the free core resonance (FCR) whose frequency falls in the diurnal tidal band. FCR observation requires highly accurate measurement of the amplitudes and phases of the near-diurnal tidal waves. In particular, the parameter estimates for minor waves K1, P1, Ψ1, and Φ1 are critically important for evaluating the FCR effect, i.e., the period and decay of this resonant mode. The progress in the experimental study of FCR is mainly due to the accumulation of the data from superconducting gravimeters and VLBI; at the same time, also the data of the precision laser strainmeters were used. In this work, the FCR effect is studied based on the long-term strain precision records by two European stations: Baksan, Russia (laser interferometer–strainmeter with a measuring armlength of 75 m [Milyukov et al., 2005; 2007] and Gran Sasso, Italy (two perpendicular laser interferometer–strainmeters, BA and BC, each with a measuring armlength of 90 m [Amoruso and Crescentini, 2009]).

Abstract P161: Variation in Five-Year Weight Loss Patterns Following Bariatric Surgery by Insurance Status

Circulation ◽  
2017 ◽  
Vol 135 (suppl_1) ◽  
Author(s):  
Erin Takemoto ◽  
Bruce Wolfe ◽  
Corey Nagel ◽  
Janne Boone-Heinonen
Keyword(s):  
Bariatric Surgery ◽  
Weight Loss ◽  
Parameter Estimates ◽  
Similar Amount ◽  
Group Model ◽  
Specific Patient ◽  
Group 6 ◽  
Medicaid Beneficiaries ◽  
Trajectory Models

In the general population, bariatric surgery facilitates sustained weight loss and remission of comorbidities (e.g., CVD). The effectiveness among Medicaid beneficiaries, a population with a disproportionately high burden of obesity, remains unclear. We sought to determine if patterns of weight change following bariatric surgery differed in patients with Medicaid compared to commercial insurance. Data were obtained from the Longitudinal Assessment of Bariatric Surgery, an observational cohort study of adults undergoing bariatric surgery (2006-2009) at one of 6 geographically diverse centers. We used group-based trajectory models (PROC TRAJ, SAS) to identify discrete groups of individuals with similar weight trajectories over 5-years; we considered cubic trajectory models with between 1 and 6 groups. We selected the 6-group model based on Bayesian Information Criteria, visual fit and statistical significance of parameter estimates. We tested demographic predictors against trajectory group membership; Medicaid (n=174) vs. Commercial (n=991) was our primary predictor of interest. Medicaid participants had higher mean weight at baseline compared to the commercially insured (307.9 vs. 291.2 lbs), but lost a similar amount of weight over time (74.8 vs 85.0 lbs). All groups experienced the most weight loss in year 1 (Figure). Group 6 was the heaviest at baseline and began to regain weight after year 1; groups 1-5 continued to lose weight through year 2. Group’s 1 & 2 weight remained stable over 5 years while groups 3-6 began to slowly regain weight. Medicaid beneficiaries were more likely to be in group 4 (OR 3.2, 95% CI: 1.2, 8.6), group 5 (OR 5.7, 95% CI: 2.0, 16.1) and group 6 (OR 7.9, 95% CI: 2.5, 25.1) compared to group 1. Medicaid beneficiaries experience substantial long term weight loss. However, they had higher baseline weight and tended to be in groups with less long-term weight loss compared to the commercially insured. Focusing on tailored interventions to specific patient groups could help maintain weight loss.

scholarly journals MicroGal Gravity Measurements with MGS-6 Micro-g LaCoste Gravimeter

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2592 ◽  
Author(s):  
Marek Przyborski ◽  
Jerzy Pyrchla ◽  
Krzysztof Pyrchla ◽  
Jakub Szulwic
Keyword(s):  
Temporal Stability ◽  
Low Noise ◽  
Reference Source ◽  
Time Stability ◽  
Superconducting Gravimeters ◽  
Gravity Measurements ◽  
Gravity Sensor ◽  
The Impact ◽  
Micro Gravity

The article discusses the registration of micro-gravity changes with the MGS-6 Micro-g LaCoste gravity sensor during static measurements. An experiment was carried out to determine how small changes in gravity can be registered using the MGS-6 system sensor. The tides of the Earth’s crust were chosen as the source of disturbance of the field with small amplitude and long-term changes. The tested sensor was placed in a geophysical observatory on a specially designed tripod. Simultaneously on the nearby concrete pillar, the registration of changes in gravity was carried out using the superconducting iGrav gravimeter. The high temporal stability of the superconducting gravimeters and the low noise combined with leading sensitivity of its reading allow it to be considered as a reliable reference source for MGS-6. The article discusses the impact of non-leveling changes of the MGS-6 gravimetry on the reading and determines the size of its non-linear drift. The obtained differences in indications between devices did not exceed 50 μ Gal for 68% of data. The measurements also showed excellent time stability of the MGS-6 measurement system. The data collected during the experiment allowed determining the level of accuracy that can be sought during real measurements using the MGS-6 system on research vessels. They also give an overview of the dynamics of the drift phenomenon of the analyzed research system.

Modeling Population Dynamics of Kochia (Bassia scoparia) in Response to Diverse Weed Control Options

Weed Science ◽  
2019 ◽  
Vol 67 (1) ◽  
pp. 57-67 ◽  
Author(s):  
O. Adewale Osipitan ◽  
J. Anita Dille ◽  
Muthukumar V. Bagavathiannan ◽  
Stevan Z. Knezevic
Keyword(s):  
Population Dynamics ◽  
Population Growth ◽  
Weed Control ◽  
Seed Production ◽  
Seedling Recruitment ◽  
Control Strategies ◽  
Effective Control ◽  
Parameter Estimates ◽  
Herbicide Resistant

AbstractKochia [Bassia scoparia(L.) A. J. Scott] is a problematic weed species across the Great Plains, as it is spreading fast and has developed herbicide-resistant biotypes. It is imperative to understand key life-history stages that promote population expansion ofB. scopariaand control strategies that would provide effective control of these key stages, thereby reducing population growth. Diversifying weed control strategies has been widely recommended for the management of herbicide-resistant weeds. Therefore, the objectives of this study were to develop a simulation model to assess the population dynamics ofB. scopariaand to evaluate the effectiveness of diverse weed control strategies on long-term growth rates ofB. scopariapopulations. The model assumed the existence of a glyphosate-resistant (GR) biotype in theB. scopariapopulation, but at a very low proportion in a crop rotation that included glyphosate-tolerant corn (Zea maysL.) and soybean [Glycine max(L.) Merr.]. The parameter estimates used in the model were obtained from various ecological and management studies onB. scoparia. Model simulations indicated that seedling recruitment and survival to seed production were more important than seedbank persistence forB. scopariapopulation growth rate. Results showed that a diversified management program, including glyphosate, could provide excellent control ofB. scopariapopulations and potentially eliminate already evolved GRB. scopariabiotypes within a given location. The most successful scenario was a diverse control strategy that included one or two preplant tillage operations followed by preplant or PRE application of herbicides with residual activities and POST application of glyphosate; this strategy reduced seedling recruitment, survival, and seed production during the growing season, with tremendous negative impacts on long-term population growth and resistance risk inB. scoparia.

scholarly journals Quantitative investigations of different vaccination policies for the control of congenital rubella syndrome (CRS) in the United Kingdom

1986 ◽  
Vol 96 (2) ◽  
pp. 305-333 ◽  
Author(s):  
R. M. Anderson ◽  
B. T. Grenfell
Keyword(s):  
Young Male ◽  
Parameter Estimates ◽  
Male And Female ◽  
Teenage Girls ◽  
Congenital Rubella ◽  
The United Kingdom ◽  
Age Related ◽  
Model Predictions ◽  
Female Children

SUMMARYThe paper examines predictions of the impact of various one-, two- and three-stage vaccination policies on the incidence of congenital rubella syndrome (CRS) in the United Kingdom with the aid of a mathematical model of the transmission dynamics of rubella virus. Parameter estimates for the model are derived from either serological data or case notifications, and special attention is given to the significance of age-related changes in the rate of exposure to rubella infection and heterogeneous mixing between age groups. Where possible, model predictions are compared with observed epidemiological trends.The principal conclusion of the analyses is that benefit is to be gained in the UK, both in the short and long term, by the introduction of a multiple-stage vaccination policy involving high levels of vaccination coverage of young male and female children (at around two years of age) and teenage girls (between the ages of 10–15 years), plus continued surveillance and vaccination of adult women in the child-bearing age classes. Model predictions suggest that to reduce the incidence of CRS in future years, below the level generated by a continuation of the current UK policy (the vaccination of teenage girls), would require high rates of vaccination > 60%) of both boys and girls at around two years of age. Numerical studies also suggest that uniform vaccination coverage levels of greater than 80–85% of young male and female children could, in the long term (40 years or more), eradicate rubella virus from the population. The robustness of these conclusions with respect to the accuracy of parameter estimates and various assumptions concerning the pattern of age-related change in exposure to infections and ‘who acquires infection from whom’ is discussed.

scholarly journals Semidiurnal Baroclinic Tides on the Central Oregon Inner Shelf

2015 ◽  
Vol 45 (10) ◽  
pp. 2640-2659 ◽  
Author(s):  
Sutara H. Suanda ◽  
John A. Barth
Keyword(s):  
Three Dimensional ◽  
Circulation Model ◽  
Inner Shelf ◽  
Oregon Coast ◽  
Tidal Waves ◽  
Linearly Polarized ◽  
Long Term Observation ◽  
Inner Continental Shelf ◽  
Baroclinic Current

AbstractSemidiurnal velocity and density oscillations are examined over the mid- and inner continental shelf near Heceta Bank on the Oregon coast. Measurements from two long-term observation networks with sites on and off the submarine bank reveal that both baroclinic velocities and displacements are dominated by the first mode, with larger velocities on the midshelf and northern parts of the bank. Midshelf sites have current ellipses that are near the theoretical value for single, progressive internal tidal waves compared to more linearly polarized currents over the inner shelf. Baroclinic current variability is not correlated to the spring–neap cycle and is uncorrelated between mooring locations. An idealized model of two internal waves propagating from different directions reproduces some of the observed variability in semidiurnal ellipse parameters. At times, the phasing between moorings along a cross-shelf transect are consistent with onshelf wave propagation, a characteristic also present in the output of a three-dimensional regional circulation model. Regional wind-driven upwelling/downwelling influences stratification at all shelf moorings. At locations north of the bank, stronger baroclinic velocities were found during periods of higher background stratification.

The regulation of malaria parasitaemia: parameter estimates for a population model

Parasitology ◽  
1995 ◽  
Vol 110 (2) ◽  
pp. 115-122 ◽  
Author(s):  
M. B. Gravenor ◽  
A. R. Mclean ◽  
D. Kwiatkowski
Keyword(s):  
Clinical Observation ◽  
Natural Infection ◽  
Growth Potential ◽  
Parameter Estimates ◽  
Classical Studies ◽  
Parasite Replication ◽  
Population Interaction ◽  
High Degree

SUMMARYClassical studies of non-immune individuals infected with Plasmodium falciparum reveal that the infection may be regulated for long periods at a relatively stable parasite density, despite the enormous growth potential of a parasite that continually replicates within host erythrocytes. This suggests that the parasite population may be controlled by density-dependent mechanisms, and in theory the most obvious of these is competition between parasites for host erythrocytes. Here we evaluate the role of this mechanism in the regulation of parasitaemia, by modelling the basic population interaction between parasites and erythrocytes in a form that allows all the essential parameters to be estimated from clinical data. Our results show that competition cannot account for the total regulation of P. falciparum, but when combined with immune mechanisms it may play a more important role than is generally supposed. Further analysis of the model indicates that in the long term, parasite replication at low parasite densities can contribute significantly to the high degree of anaemia observed in natural infection, a conclusion which is not obvious from simple clinical observation.

Estimation of Free Core Resonance Parameters Based on Long-Term Strain Observations in the Diurnal Frequency Band

2019 ◽  
Vol 55 (3) ◽  
pp. 389-396 ◽  
Author(s):  
V. K. Milyukov ◽  
A. Amoruso ◽  
L. Crescentini ◽  
A. P. Mironov ◽  
A. V. Myasnikov ◽  
...  
Keyword(s):  
Frequency Band ◽  
Resonance Parameters ◽  
Free Core Resonance

Long-term observations at the Geodynamic Observatory Moxa: Can we identify evidence for climate change?

2020 ◽  
Author(s):  
Cornelius Schwarze ◽  
Thomas Jahr ◽  
Andreas Goepel ◽  
Valentin Kasburg ◽  
Nina Kukowski
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Optical Fibre ◽  
Temperature Fluctuations ◽  
Subsurface Temperature ◽  
Loading Effect ◽  
Tidal Waves ◽  
The Earth

<p>Longterm geophysical recordings of natural Earth’s parameters besides other signals also may contain past and ongoing temperature fluctuations, as they are occurring e.g. when groundwater moves or when climate changes. Similarly, repeated logs or continuous recordings reveal the amount of ongoing climate fluctuations. However, such thermal signals in the subsurface also may have other causes, e.g. groundwater motion or fluid infiltration after strong rainfall events. The Geodynamic Observatory Moxa of the Friedrich-Schiller University Jena, Germany, is an ideal test site for long-term monitoring of the subsurface temperature distribution in boreholes using optical fibre temperature-sensing, as it is equipped with a variety of complementary sensors.</p><p>A 100 m deep borehole on the ground of the Observatory, is equipped with an optical fibre and a water level gauge. Clearly shown in the records of the first five years of continuous recordings are seasonal temperature fluctuations. Seasonal fluctuations could be identified down to a depth of about 20 m and diurnal temperature signals down to 1.2 m. Precipitation events may influence subsurface temperature still in a depth as deep as 15 m. Besides these, temperature anomalies were detected at two depths, 20 m and 77 m below the surface. These anomalies most probably result from enhanced groundwater flow in aquifers. Recordings of deformation from laser strain meter systems installed in a gallery at Moxa, which are highly sensitive to pore pressure fluctuations, and measuring the physical properties during drilling the borehole, help to identify and quantify the causes of the observed  temperature fluctuations.</p><p>For more than 20 years variations of the Earth’s gravity field have been observed at the Observatory Moxa employing the superconducting gravimeter CD-034. Besides the free oscillations of the Earth and hydrological effects, the tides of the solid Earth are the strongest signals found in the time series. Tidal analysis of the main constituents leads to obtaining the indirect effect for all tidal waves which is mainly controlled by the loading effect of the oceans. Satellite altimetry revealed a mean global sea level rise of about 3.3 mm/a which may be caused amongst others mainly by ice melting processes in the polar regions. However, more detailed analyses and resulting global maps show that the sea level rise is not uniformly distributed over all oceans. This means that actual and future tidal water mass movements could vary regionally and even locally.  As a consequence, the tidal parameter controlled by the ocean loading effect could change over long-term observation periods and it should possibly be detectable as a trend or temporal variation of the tidal gravity parameters locally. Actually, a long-term change of the tidal parameters is observed for the main tidal waves like K1 and O1 in the diurnal and for M2 and K2 in the semi-diurnal frequency band. However, it is not clear if these changes can be correlated with sea level changes as observed from satellite data. On the other hand, surface and subsurface temperature fluctuations directly reveal the size of the thermal signal inherent to climate change.</p>

scholarly journals Protective effects of health insurance against disasters: an insight from the Great East Japan Earthquake

2021 ◽  
pp. 1-17
Author(s):  
Michio Yuda ◽  
Jinkook Lee
Keyword(s):  
Negative Impact ◽  
Great East Japan Earthquake ◽  
Care Utilization ◽  
Protective Effects ◽  
Term Care ◽  
Tidal Waves ◽  
The Pacific ◽  
Significant Negative Impact ◽  
Health Deterioration

Abstract The Great East Japan Earthquake of March 2011 and it's massive tidal waves wreaked devastating damage on residences and communities along 400 km of the Pacific coast in Japan. Using the panel data from the Japanese Study of Aging and Retirement, we estimate the effects of this disaster on individual health, finding a significant negative impact on the health of those in the area. In addition, we exploit a discontinuous decrease in copayments for medical care at the age of 70 years and find that the reduction in copayment increased medical and long-term care utilization and significantly reduced health deterioration after the earthquake.

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