scholarly journals Publisher Correction: Mechanisms for log normal concentration distributions in the environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
August Andersson
Keyword(s):  
Normal Concentration ◽  
Log Normal

scholarly journals Mechanisms for log normal concentration distributions in the environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
August Andersson
Keyword(s):  
Data Analysis ◽  
Normal Concentration ◽  
First Order ◽  
Log Normal ◽  
Frequent Observation ◽  
Source And Sink

AbstractLog normal-like concentration distributions are ubiquitously observed in the environment. However, the mechanistic origins are not well understood. In this paper, we show that first order exponential kinetics onsets log-normal concentration distributions, under certain assumptions. Given the ubiquity of exponential kinetics, e.g., source and sink processes, this model suggests an explanation for the frequent observation in the environment, and elsewhere. We compare this model to other mechanisms affecting concentration distributions, e.g., source mixing. Finally, we discuss possible implications for data analysis and modelling, e.g., log-normal rates and fluxes.

Increased Serum Concentration of Free L-Triiodothyronine in Patients Treated with L-Thyroxine

1983 ◽  
Vol 22 (05) ◽  
pp. 251-254
Author(s):  
R. Schmitz ◽  
H. Bongers ◽  
A. Löw ◽  
J. Mahlstedt ◽  
K. Joseph ◽  
...  
Keyword(s):  
Oral Dose ◽  
Serum Concentration ◽  
Normal Level ◽  
Binding Sites ◽  
Carrier Proteins ◽  
Normal Range ◽  
Free T4 ◽  
Normal Concentration ◽  
Free T3 ◽  
High Doses

This study demonstrates that in spite of measured normal concentrations of carrier proteins one cannot deduce in all cases a normal fT3 from a normal level of TT3 when 1-thyroxine given for diagnostic or therapeutic purposes is present in excess. The displacement of 1-triiodothyronine from its binding sites is shown in 35 patients with non-toxic goitre who received an oral dose of 200 μg 1-thyroxine/die for two weeks. Apart from a significant increase of TT4 (from 7.85 to 14.21 μg/dl ≙ + 81 %) and of fT4 (from 1.58 to 3.7 ng/dl ≙ + 134%) there is only a slight increase in TT3 from 148 to 158 ng/dl (≙ + 10%) after 14 days of treatment. By contrast fT3 rises clearly from 4.97 to 8.07 pg/ml ≙ + 63% (normal range: 2.8-5.6 pg/ml). Compared with the increase of TT3 (+ 10%) the free T3 rises by a factor of 6.3 (63 %/10%). On account of higher affinity of 1-thyroxine to binding proteins the free T4 is influenced to a lesser degree. Compared with the increase of TT4 (+ 81 %) free T4 rises by a factor of 1.6 (134%/81 %). It is supposed that the serum concentration of free T3 can be increased despite a normal concentration of TT3 when 1-thyroxine is present in excess. Therefore, for laboratory work fT3 should be assigned a higher validity than TT3 when patients are treated with comparatively high doses of 1-thyroxine.

Prediction of Haemoglobin Level by Some Probability Distribution

2020 ◽  
Vol 9 (1) ◽  
pp. 84-88
Author(s):  
Govinda Prasad Dhungana ◽  
Laxmi Prasad Sapkota
Keyword(s):  
Probability Distribution ◽  
Normal Distribution ◽  
Goodness Of Fit ◽  
Continuous Variable ◽  
Hemoglobin Level ◽  
Chi Square ◽  
Chi Square Test ◽  
Log Normal ◽  
Two Parameters ◽  
Best Fit

 Hemoglobin level is a continuous variable. So, it follows some theoretical probability distribution Normal, Log-normal, Gamma and Weibull distribution having two parameters. There is low variation in observed and expected frequency of Normal distribution in bar diagram. Similarly, calculated value of chi-square test (goodness of fit) is observed which is lower in Normal distribution. Furthermore, plot of PDFof Normal distribution covers larger area of histogram than all of other distribution. Hence Normal distribution is the best fit to predict the hemoglobin level in future.

Comparison and Evaluation of Different Microbiological Quality Criteria for Shellfish and Shellfish-Growing Waters

1993 ◽  
Vol 27 (3-4) ◽  
pp. 31-34 ◽  
Author(s):  
E. Martinez-Manzanares ◽  
M. A. Moriñigo ◽  
D. Castro ◽  
M. C. Balebona ◽  
J. J. Borrego
Keyword(s):  
Sea Water ◽  
Microbiological Quality ◽  
Quality Criteria ◽  
Human Consumption ◽  
Faecal Coliforms ◽  
Mediterranean Countries ◽  
Four Seasons ◽  
Microbiological Criteria ◽  
Chamelea Gallina ◽  
Log Normal

The objective of this study is to compare different microbiological criteria based on the control of shellfish-growing waters and shellfish flesh, to assess the microbiological quality of the shellfish harvested in a marine zone affected by discharges of a moderately polluted river. Two species of shellfish grown in Mediterranean countries, cockles (Cardium edule) and striped venus (Chamelea gallina) were chosen to carry out this study. A total of 55 samples of diellfish and sea water were collected over the four seasons of the year. According to the results obtained, the US, EEC and Spanish criteria, based on the level of faecal coliforms in shellfish flesh, guaranteed appropriately their safety for human consumption, but among the criteria based on the level of Escherichia coli, only the Australian criterion has been shown to be totally safe, this microorganism being the best indicator of the presence of Vibrio parahaemolyticus and Salmonella. For the criteria based on the analysis of indicators in seawater, the indicators which relate to the age of faecal pollution, such as spores of clostridium sulfite reducer and faecal streptococci are the best indexes of the presence of pathogens in shellfish. Furthermore, criteria that establish the percentage of water samples that fulfill the microbiological level specified, or log-normal distributions of indicators such as total coliforms, faecal coliforms and E. coli, are better than mean counts.

Bacterial die-away rates in red sea waters

1995 ◽  
Vol 32 (2) ◽  
pp. 45-52 ◽  
Author(s):  
H. Z. Sarikaya ◽  
A. M. Saatçi
Keyword(s):  
Solar Radiation ◽  
Decay Rate ◽  
Sea Water ◽  
Membrane Filter ◽  
Linear Regression Analysis ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Decay Rate Constant ◽  
Solar Intensity ◽  
Log Normal

Total coliform bacteria have been chosen as the indicator organism. Coliform die-away experiments have been carried out in unpolluted sea water samples collected at about 100 m off the coastline and under controlled environmental conditions. The samples were transformed into one litre clean glass beakers which were kept at constant temperature and were exposed to the solar radiation. The membrane filter technique was used for the coliform analysis. The temperature ranged from 20 to 40° C and the dilution ratios ranged from 1/50 to 1/200. Coliform decay rate in the light has been expressed as the summation of the coliform decay rate in the dark and the decay rate due to solar radiation. The solar radiation required for 90 percent coliform removal has been found to range from 17 cal/cm2 to 40 cal/cm2 within the temperature range of 25 to 30° C. Applying the linear regression analysis two different equations have been given for the high (I>10 cal/cm2.hour) and low solar intensity ranges in order to determine the coliform decay rate constant as a function of the solar intensity. T-90 values in the light have been found to follow log-normal distribution with a median T-90 value of 32 minutes. The corresponding T-90 values in the dark were found to be 70-80 times longer. Coliform decay rate in the dark has been correlated with the temperature.

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