scholarly journals Effects of Homeopathic Preparations of Mercurius corrosivus on the Growth Rate of Severely Mercury-Stressed Duckweed Lemna gibba L.

Homeopathy ◽  
2019 ◽  
Vol 108 (02) ◽  
pp. 128-138 ◽  
Author(s):  
Tim Jäger ◽  
Sandra Würtenberger ◽  
Stephan Baumgartner
Keyword(s):  
Growth Rate ◽  
Stress Intensity ◽  
Growth Rates ◽  
Statistical Power ◽  
Test System ◽  
Lemna Gibba ◽  
Image Analysis System ◽  
Water Control ◽  
Time Period ◽  
The Stability

Background We developed a bioassay with mercury-stressed duckweed (Lemna gibba L.) to study potential effects of homeopathically potentised mercury(II) chloride (Mercurius corrosivus [Merc-c.]). The response of this bioassay to homeopathic treatments as a function of stress intensity was also of interest. Methods Duckweed was severely stressed with mercury(II) chloride for 48 hours. Afterwards plants grew in either Merc-c. (seven different potency levels, 24x to 30x) or water controls (unsuccussed and succussed water) for 7 days. Growth rates of the frond (leaf) area were determined using a computerised image analysis system for different time intervals between the measurements on days 0, 3 and 7. Three independent experiments with potentised Merc-c. each were evaluated. Additionally, three water control experiments were analysed to investigate the stability of the experimental set-up (systematic negative control [SNC] experiments). All experiments were randomised and blinded. Results Unsuccussed and succussed water did not significantly differ in terms of duckweed growth rate. The SNC experiments did not yield any significant effects, providing evidence for the stability of the experimental system. Data from the two control groups and the seven treatment groups (Merc-c. 24x–30x) were each pooled to increase the statistical power. Duckweed growth rates for day 0 to 3 were reduced (p < 0.05) after application of Merc-c. compared with the controls. Growth rates for day 3 to 7 were not influenced by the homeopathic preparations. Conclusions The present test system with Lemna gibba L. that was severely stressed by mercury yielded evidence for specific effects of Merc-c. 24x to 30x, namely a growth reduction in the first time period (day 0–3). This is in contrast to former experiments with slightly arsenic-stressed duckweed, where a growth increase was observed in the second time period (day 2–6). We hypothesise that the differing results are associated with the level of stress intensity (severe versus slight).

scholarly journals Effects of Homeopathic Arsenicum Album, Nosode, and Gibberellic Acid Preparations on the Growth Rate of Arsenic-Impaired Duckweed (Lemna gibbaL.)

2010 ◽  
Vol 10 ◽  
pp. 2112-2129 ◽  
Author(s):  
Tim Jäger ◽  
Claudia Scherr ◽  
Meinhard Simon ◽  
Peter Heusser ◽  
Stephan Baumgartner
Keyword(s):  
Growth Rate ◽  
Gibberellic Acid ◽  
Growth Rates ◽  
Statistical Power ◽  
Test System ◽  
Negative Control ◽  
Test Substance ◽  
Image Analysis System ◽  
Water Control ◽  
Analysis System

This study evaluated the effects of homeopathically potentized Arsenicum album, nosode, and gibberellic acid in a bioassay with arsenic-stressed duckweed (Lemna gibbaL.). The test substances were applied in nine potency levels (17x, 18x, 21x–24x, 28x, 30x, 33x) and compared with controls (unsuccussed and succussed water) regarding their influence on the plant’s growth rate. Duckweed was stressed with arsenic(V) for 48 h. Afterwards, plants grew in either potentized substances or water controls for 6 days. Growth rates of frond (leaf) area and frond number were determined with a computerized image analysis system for different time intervals (days 0–2, 2–6, 0–6). Five independent experiments were evaluated for each test substance. Additionally, five water control experiments were analyzed to investigate the stability of the experimental setup (systematic negative control experiments). All experiments were randomized and blinded. The test system exhibited a low coefficient of variation (≈1%). Unsuccussed and succussed water did not result in any significant differences in duckweed growth rate. Data from the control and treatment groups were pooled to increase statistical power. Growth rates for days 0–2 were not influenced by any homeopathic preparation. Growth rates for days 2–6 increased after application of potentized Arsenicum album regarding both frond area (p< 0.001) and frond number (p< 0.001), and by application of potentized nosode (frond area growth rate only,p< 0.01). Potencies of gibberellic acid did not influence duckweed growth rate. The systematic negative control experiments did not yield any significant effects. Thus, false-positive results can be excluded with high certainty. To conclude, the test system withL. gibbaimpaired by arsenic(V) was stable and reliable. It yielded evidence for specific effects of homeopathic Arsenicum album preparations and it will provide a valuable tool for future experiments that aim at revealing the mode of action of homeopathic preparations. It may also be useful to investigate the influence of external factors (e.g., heat, electromagnetic radiation) on the effects of homeopathic preparations.

scholarly journals Effects of Homeopathic Preparations of Mercurius corrosivus on the Growth Rate of Moderately Mercury-Stressed Duckweed Lemna gibba L

Homeopathy ◽  
2021 ◽  
Author(s):  
Tim Jäger ◽  
Sandra Würtenberger ◽  
Stephan Baumgartner
Keyword(s):  
Growth Rate ◽  
Stress Level ◽  
Growth Rates ◽  
Statistical Power ◽  
Experimental System ◽  
Negative Control ◽  
Lemna Gibba ◽  
Image Analysis System ◽  
Analysis System ◽  
Observation Period

Abstract Background A bioassay with severely mercury-stressed duckweed (Lemna gibba L.) had revealed growth-inhibiting effects of homeopathically potentised mercury(II) chloride (Mercurius corrosivus, Merc-c.). We hypothesised that effects of potentised preparations are dependent on the stress level of the organisms used in the bioassay. The aim of the present investigation was to examine the response of duckweed to potentised Merc-c. at a lower stress level. Methods Duckweed was moderately stressed with 2.5 mg/L mercury(II) chloride for 48 hours. Afterwards plants grew in either Merc-c. (seven different potency levels, 24x–30x) or water controls (unsuccussed or succussed water) for 7 days. Growth rates of the frond (leaf) area were determined using a computerised image-analysis system for day 0–3 and 3–7. Three independent experiments with potentised Merc-c. and three systematic negative control experiments were performed. All experiments were randomised and blinded. Results Unsuccussed and succussed water did not significantly differ in their effects on duckweed growth rate. The systematic negative control experiments did not yield any significant effects, thus providing evidence for the stability of the experimental system. Data from the two control groups and the seven treatment groups (Merc-c. 24x–30x) were each pooled to increase statistical power. Duckweed growth rates for day 3–7 were enhanced (p < 0.05) after application of Merc-c. compared with the controls. Growth rates for day 0–3 were not influenced by the homeopathic preparations. Conclusions Moderately mercury-stressed Lemna gibba L. yielded evidence of growth-enhancing specific effects of Merc-c. 24x–30x in the second observation period (day 3–7). This observation is complementary to previous experiments with severely mercury-stressed duckweed, in which a decrease in growth was observed in the first observation period (day 0–3). We hypothesise that the differing results are associated with the level of stress intensity (moderate vs. severe).

scholarly journals Reproducibility of effects of the homeopathic dilutions 14x - 30x of gibberellic acid on growth of Lemna gibba L.

2021 ◽  
Vol 11 (40) ◽  
pp. 196-197
Author(s):  
Vera Majewsky ◽  
Claudia Scherr ◽  
Sebastian Arlt ◽  
Peter Klocke ◽  
Stephan Baumgartner
Keyword(s):  
Gibberellic Acid ◽  
Test Organism ◽  
Test System ◽  
Negative Control ◽  
Control Area ◽  
System Stability ◽  
Lemna Gibba ◽  
Test Substance ◽  
Image Analysis System ◽  
Water Control

Background: Reproducibility of investigations in homeopathy is still challenging. Duckweed (Lemna gibba L.), a monocotyledonous waterplant which mostly reproduces vegetatively and therefore builds genetically identical clones, may be a suitable test system for standardised trials. Aims: This study investigated if formerly observed effects of gibberellic acid 14x – 30x on growth of Lemna gibba were reproducible. Methododology: Duckweed was grown in dilutions of gibberellic acid (14x–30x) as well as once succussed (c1) and unsuccussed (c0) water control. Area-related growth rate for day 0–7 was determined by a computerised image analysis system. Three series including five independent blinded and randomised experiments each were carried out in the same way as in the original study. Only time and conductor of experiments were modified. System stability was controled by three series of systematic negative control (SNC) experiments with the same set-up, but distilled and autoclaved water was used as the only test substance. According to the series with gibberellic acid, each serie of SNC experiments included five experiments. Full two-way ANOVA (α = 5%) was used for statistical analysis. Independent variables were treatment and experiment number, dependent variable was r(area) for day 0–7. Data of each experiment was normalised to its mean value to allow a better comparison between experiments. Only if the global ANOVA F-test was significant (p < 0.05) we compared the investigated groups with Fisher`s LSD test (protected Fisher`s LSD). Results: No specific effects of agitated dilutions of gibberellic acid were found in the first two replication series (p=0.263 and p=0.062). In the third serie with gibbous Lemna gibba L. we observed a significant effect (p=0.009) of the homeopathic treatment, however growth was increased in contrast to decreasing in the former study. Variability in experiments with gibberellic acid 14x – 30x was lower than in SNC experiments. The stability of the experimental system was verified by the SNC experiments. Conclusions: When designing new studies to investigate reproducibility, different physiological states of the test organism must be considered. Variability might be an interesting parameter to investigate effects of homeopathic remedies in basic research.

scholarly journals Instability Through Anisotropy in Spherical Stellar Systems

1987 ◽  
Vol 127 ◽  
pp. 515-516
Author(s):  
P.L. Palmer ◽  
J. Papaloizou
Keyword(s):  
Growth Rate ◽  
Eigenvalue Problem ◽  
Growth Rates ◽  
Stellar Systems ◽  
Matrix Eigenvalue Problem ◽  
Simple Method ◽  
Anisotropic Models ◽  
Poisson Equations ◽  
Degree Of Anisotropy ◽  
The Stability

We consider the linear stability of spherical stellar systems by solving the Vlasov and Poisson equations which yield a matrix eigenvalue problem to determine the growth rate. We consider this for purely growing modes in the limit of vanishing growth rate. We show that a large class of anisotropic models are unstable and derive growth rates for the particular example of generalized polytropic models. We present a simple method for testing the stability of general anisotropic models. Our anlysis shows that instability occurs even when the degree of anisotropy is very slight.

On Estimates for Growth Rates of Unstable Azimuthal Disturbances in the Stability Problem of Swirling Flows with Radius- Dependent Density

2017 ◽  
Vol 13 (3) ◽  
pp. 1-12
Author(s):  
Halle Dattu Malai Subbiah
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Stability Problem ◽  
Variable Density ◽  
Swirling Flows ◽  
Wave Number ◽  
Two Dimensional ◽  
Azimuthal Wave Number ◽  
The Stability ◽  
Dependent Density

Estimates for the growth rate of unstable two-dimensional disturbances to swirling flows with variable density are obtained and as a consequence it is proved that the growth rate tends to zero as the azimuthal wave number tends to infinity for two classes of basic flows.

Reproducibility of the effects of homeopathically potentised Argentum nitricum on the growth of Lemna gibba L. in a randomised and blinded bioassay

Homeopathy ◽  
2017 ◽  
Vol 106 (03) ◽  
pp. 145-154 ◽  
Author(s):  
Claudia Scherr ◽  
Claudia Schneider ◽  
Sebastian Patrick Arlt ◽  
Stephan Baumgartner ◽  
Vera Majewsky
Keyword(s):  
Growth Rate ◽  
Treatment Effect ◽  
Significant Interaction ◽  
Test System ◽  
Negative Control ◽  
Original Study ◽  
System Stability ◽  
Lemna Gibba ◽  
Growth State ◽  
Successful Reproduction

Background: A previous study reported a significant statistical interaction between experiment date and treatment effect of Argentum nitricum 14x–30x on the growth rate of duckweed (Lemna gibba L.). The aim of the present study was to investigate the stability of the test system and intra-laboratory reproducibility of the effects found. Methods: Duckweed was treated with A. nitricum potencies (14x–30x) as well as succussed and unsuccussed water controls. The outcome parameter area-related growth rate for day 0–7 was determined by a computerised image analysis system in two series of independent randomised and blinded experiments. Systematic negative control (SNC) experiments were carried out to investigate test system stability. Statistical analysis was performed with full two-way analysis of variance (ANOVA) and protected Fisher's Least Significant Difference (LSD) test. Results: In the first repetition series we found a significant treatment effect (p = 0.016), while in the second series no effect was observed. The negative control experiments showed that the experimental system was stable. An a posteriori subgroup analysis concerning gibbosity revealed the importance of this growth state of L. gibba for successful reproduction of the statistically significant interaction in the original study; flat: no interaction (p = 0.762); slight gibbosity: no interaction (p = 0.356); medium gibbosity: significant interaction (p = 0.031), high gibbosity: highly significant interaction (p = 0.005). Conclusions: With the original study design (disregarding gibbosity status of L. gibba) results of the original study could not be reproduced sensu stricto. We conclude that the growth state gibbosity is crucial for successful reproduction of the original study. Different physiological states of the test organisms used for bioassays for homeopathic basic research must carefully be considered.

scholarly journals Computation and analysis of atmospheric carbon dioxide annual mean growth rates from satellite observations during 2003–2016

2018 ◽  
Vol 18 (23) ◽  
pp. 17355-17370 ◽  
Author(s):  
Michael Buchwitz ◽  
Maximilian Reuter ◽  
Oliver Schneising ◽  
Stefan Noël ◽  
Bettina Gier ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Growth Rates ◽  
El Niño ◽  
Atmospheric Carbon Dioxide ◽  
Fossil Fuel ◽  
El Nino ◽  
Time Period ◽  
Atmospheric Carbon ◽  
The Impact

Abstract. The growth rate of atmospheric carbon dioxide (CO2) reflects the net effect of emissions and uptake resulting from anthropogenic and natural carbon sources and sinks. Annual mean CO2 growth rates have been determined from satellite retrievals of column-averaged dry-air mole fractions of CO2, i.e. XCO2, for the years 2003 to 2016. The XCO2 growth rates agree with National Oceanic and Atmospheric Administration (NOAA) growth rates from CO2 surface observations within the uncertainty of the satellite-derived growth rates (mean difference ± standard deviation: 0.0±0.3 ppm year−1; R: 0.82). This new and independent data set confirms record-large growth rates of around 3 ppm year−1 in 2015 and 2016, which are attributed to the 2015–2016 El Niño. Based on a comparison of the satellite-derived growth rates with human CO2 emissions from fossil fuel combustion and with El Niño Southern Oscillation (ENSO) indices, we estimate by how much the impact of ENSO dominates the impact of fossil-fuel-burning-related emissions in explaining the variance of the atmospheric CO2 growth rate. Our analysis shows that the ENSO impact on CO2 growth rate variations dominates that of human emissions throughout the period 2003–2016 but in particular during the period 2010–2016 due to strong La Niña and El Niño events. Using the derived growth rates and their uncertainties, we estimate the probability that the impact of ENSO on the variability is larger than the impact of human emissions to be 63 % for the time period 2003–2016. If the time period is restricted to 2010–2016, this probability increases to 94 %.

Thermoacoustic Instability Model With Porous Media: Linear Stability Analysis and the Impact of Porous Media

2018 ◽  
Author(s):  
Cody S. Dowd ◽  
Joseph W. Meadows
Keyword(s):  
Growth Rate ◽  
Porous Media ◽  
Stability Analysis ◽  
Frequency Shift ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Growth Rates ◽  
Thermoacoustic Instability ◽  
The Stability ◽  
The Impact

Lean premixed (LPM) combustion systems are susceptible to thermoacoustic instability, which occurs when acoustic pressure oscillations are in phase with the unsteady heat release rates. Porous media has inherent acoustic damping properties, and has been shown to mitigate thermoacoustic instability; however, theoretical models for predicting thermoacoustic instability with porous media do not exist. In the present study, a 1-D model has been developed for the linear stability analysis of the longitudinal modes for a series of constant cross-sectional area ducts with porous media using a n-Tau flame transfer function. By studying the linear regime, the prediction of acoustic growth rates and subsequently the stability of the system is possible. A transfer matrix approach is used to solve for acoustic perturbations of pressure and velocity, stability growth rate, and frequency shift without and with porous media. The Galerkin approximation is used to approximate the stability growth rate and frequency shift, and it is compared to the numerical solution of the governing equations. Porous media is modeled using the following properties: porosity, flow resistivity, effective bulk modulus, and structure factor. The properties of porous media are systematically varied to determine the impact on the eigenfrequencies and stability growth rates. Porous media is shown to increase the stability domain for a range of time delays (Tau) compared to similar cases without porous media.

Thermoacoustic Instability Model With Porous Media: Linear Stability Analysis and the Impact of Porous Media

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Cody S. Dowd ◽  
Joseph W. Meadows
Keyword(s):  
Growth Rate ◽  
Porous Media ◽  
Stability Analysis ◽  
Frequency Shift ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Growth Rates ◽  
Thermoacoustic Instability ◽  
The Stability ◽  
The Impact

Lean premixed (LPM) combustion systems are susceptible to thermoacoustic instability, which occurs when acoustic pressure oscillations are in phase with the unsteady heat release rates. Porous media has inherent acoustic damping properties and has been shown to mitigate thermoacoustic instability; however, theoretical models for predicting thermoacoustic instability with porous media do not exist. In the present study, a one-dimensional (1D) model has been developed for the linear stability analysis of the longitudinal modes for a series of constant cross-sectional area ducts with porous media using a n-Tau flame transfer function (FTF). By studying the linear regime, the prediction of acoustic growth rates and subsequently the stability of the system is possible. A transfer matrix approach is used to solve for acoustic perturbations of pressure and velocity, stability growth rate, and frequency shift without and with porous media. The Galerkin approximation is used to approximate the stability growth rate and frequency shift, and it is compared to the numerical solution of the governing equations. Porous media is modeled using the following properties: porosity, flow resistivity, effective bulk modulus, and structure factor. The properties of porous media are systematically varied to determine the impact on the eigenfrequencies and stability growth rates. Porous media is shown to increase the stability domain for a range of time delays (Tau) compared to similar cases without porous media.

Numerical parameter study of stability against resistive axisymmetric modes for doublets

1978 ◽  
Vol 20 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Torkil H. Jensen ◽  
F. W. McClain
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Vertical Direction ◽  
Parameter Study ◽  
Numerical Parameter ◽  
Numerical Examples ◽  
Conducting Wall ◽  
The Stability ◽  
The Many

Stability and growth rates of resistive axisymmetric modes for doublets have been studied numerically. Because of the many parameters entering the problem this study has the form of a survey of features that are believed to be most important for stability. In general it is found that the most dangerous mode is one that either elongates or contracts the plasma in the vertical direction. Stability, and in the case of instability, the growth rate, depends on the proximity of a conducting wall surrounding the plasma. Numerical examples of this are given both for cases of a rectangular wall shape and an indented wall shape. Examples are also given that indicate the sensitivity to parameters characterizing the equilibrium. Finally, an example is given for the case of a wall with a finite resistivity. It is shown that such a wall does not affect the stability, but decreases the growth rate relative to a case where the wall is absent.

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