scholarly journals An empirical method for absolute calibration of coccolith thickness

2017 ◽  
Author(s):  
Saúl González-Lemos ◽  
José Guitián ◽  
Miguel-Ángel Fuertes ◽  
José-Abel Flores ◽  
Heather M. Stoll
Keyword(s):  
Laboratory Data ◽  
Polarized Light ◽  
Empirical Method ◽  
Absolute Calibration ◽  
Light Spectra ◽  
Independent Determination ◽  
Data Comparability ◽  
Calibration Materials ◽  
Constant Slope

Abstract. As major calcifiers in the open ocean, coccolithophores play a key role in the marine carbon cycle. Because they may be sensitive to changing CO2 and ocean acidification, there is significant interest in quantifying past and present variations in their cellular calcification by quantifying the thickness of the coccoliths or calcite plates that cover their cells. Polarized light microscopy has emerged as a key tool for quantifying the thickness of these calcite plates, but the reproducibility and accuracy of such determinations has been limited by the absence of suitable calibration materials in the thickness range of coccoliths (0–4 microns). Here, we describe the fabrication of a calcite wedge with a constant slope over 15 this thickness range, and the independent determination of calcite thickness along the wedge profile. We show how the calcite wedge provides more robust calibrations in the 0 to 1.55 μm range than previous approaches using rhabdoliths. We show the particular advantages of the calcite wedge approach for developing equations to relate thickness to the interference colors that arise in calcite in the thickness range between 1.55 and 4 μm. The calcite wedge approach can be applied to develop equations relevant to the particular light spectra and intensity of any polarized light microscope system and could significantly improve within and inter-laboratory data comparability.

scholarly journals Technical note: An empirical method for absolute calibration of coccolith thickness

2018 ◽  
Vol 15 (4) ◽  
pp. 1079-1091 ◽  
Author(s):  
Saúl González-Lemos ◽  
José Guitián ◽  
Miguel-Ángel Fuertes ◽  
José-Abel Flores ◽  
Heather M. Stoll
Keyword(s):  
Laboratory Data ◽  
Polarized Light ◽  
Empirical Method ◽  
Technical Note ◽  
Absolute Calibration ◽  
Light Spectra ◽  
Data Comparability ◽  
Calibration Materials ◽  
Constant Slope

Abstract. As major calcifiers in the open ocean, coccolithophores play a key role in the marine carbon cycle. Because they may be sensitive to changing CO2 and ocean acidification, there is significant interest in quantifying past and present variations in their cellular calcification by quantifying the thickness of the coccoliths or calcite plates that cover their cells. Polarized light microscopy has emerged as a key tool for quantifying the thickness of these calcite plates, but the reproducibility and accuracy of such determinations has been limited by the absence of suitable calibration materials in the thickness range of coccoliths (0–4 µm). Here, we describe the fabrication of a calcite wedge with a constant slope over this thickness range, and the independent determination of calcite thickness along the wedge profile. We show how the calcite wedge provides more robust calibrations in the 0 to 1.55 µm range than previous approaches using rhabdoliths. We show the particular advantages of the calcite wedge approach for developing equations to relate thickness to the interference colors that arise in calcite in the thickness range between 1.55 and 4 µm. The calcite wedge approach can be applied to develop equations relevant to the particular light spectra and intensity of any polarized light microscope system and could significantly improve inter-laboratory data comparability.

scholarly journals Model-Independent Determination of the Spin of the Ω− and Its Polarization Alignment in ψ(3686)→Ω−Ω¯+

2021 ◽  
Vol 126 (9) ◽  
Author(s):  
M. Ablikim ◽  
M. N. Achasov ◽  
P. Adlarson ◽  
S. Ahmed ◽  
M. Albrecht ◽  
...  
Keyword(s):  
Independent Determination ◽  
Model Independent

scholarly journals A METHOD FOR THE INDEPENDENT DETERMINATION OF CYSTEINE AND CYSTINE IN PROTEINS

1954 ◽  
Vol 207 (2) ◽  
pp. 903-910
Author(s):  
R.D. Strickland ◽  
E.L. Martin ◽  
J.L. Riebsomer
Keyword(s):  
Independent Determination

On the three-dimensional structure and catalytic mechanism of triose phosphate isomerase

1981 ◽  
Vol 293 (1063) ◽  
pp. 159-171 ◽  
Keyword(s):  
Catalytic Mechanism ◽  
Polypeptide Chain ◽  
Three Dimensional ◽  
Triose Phosphate Isomerase ◽  
Dimensional Structure ◽  
Dihydroxyacetone Phosphate ◽  
Triose Phosphate ◽  
Independent Determination ◽  
Chicken Muscle

Triose phosphate isomerase is a dimeric enzyme of molecular mass 56000 which catalyses the interconversion of dihydroxyacetone phosphate (DHAP) and D-glyceraldehyde-3-phosphate. The crystal structure of the enzyme from chicken muscle has been determined at a resolution of 2.5 A, and an independent determination of the structure of the yeast enzyme has just been completed at 3 A resolution. The conformation of the polypeptide chain is essentially identical in the two structures, and consists of an inner cylinder of eight strands of parallel |3-pleated sheet, with mostly helical segments connecting each strand. The active site is a pocket containing glutamic acid 165, which is believed to act as a base in the reaction. Crystallographic studies of the binding of DHAP to both the chicken and the yeast enzymes reveal a common mode of binding and suggest a mechanism for catalysis involving polarization of the substrate carbonyl group.

scholarly journals The Empirical and Theoretical Miscible Characterization Method in Gas-Enhanced Oil Recovery

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Wang Chengjun ◽  
Li Xiaorui
Keyword(s):  
Oil Recovery ◽  
Research Result ◽  
Empirical Method ◽  
Reservoir Engineering ◽  
Forecasting Accuracy ◽  
Factors Affecting ◽  
Development Scheme ◽  
Gas Flooding ◽  
New Ideas

The determination of miscible characteristic is one of the key technologies for enhancing oil recovery of gas flooding. If the miscible characteristic at each development period of gas flooding can be known in real time, it will be helpful to guide gas flooding development scheme. The minimum miscible pressure (MMP) is mostly used to describe miscible characteristic. Currently, the MMP forecasting methods can be classified into two categories—the empirical method and theoretical calculation method. In this paper, the main controlling factors affecting MMP are analyzed combined with reservoir engineering method, phase equilibrium theory, reservoir numerical simulation technology, and so on. Based on this, new empirical and theoretical MMP forecasting model was built. Meanwhile, new ideas for improving forecasting accuracy through modifying miscible criterion were proposed. The calculation accuracies of the two MMP forecasting models can be improved to over 90% that is more accurate and adapted than other methods. This research result can supply new ideas for gas flooding MMP forecasting.

scholarly journals Use of the Accusport semi-automated analyser to determine blood lactate as an aid in the clinical assessment of horses with colic

2001 ◽  
Vol 72 (1) ◽  
Author(s):  
M.L. Schulman ◽  
J.P. Nurton ◽  
A.J. Guthrie
Keyword(s):  
Blood Lactate ◽  
Laboratory Data ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Tissue Perfusion ◽  
Diagnostic Methods ◽  
Initial Assessment ◽  
Clinically Normal ◽  
Case Outcome

The most useful diagnostic methods in the initial evaluation of horses with colic assess the morphological and functional status of the gastrointestinal tract and cardiovascular status. This evaluation is best achieved using a combination of clinical and laboratory data. Blood lactate concentration (BL) is one of these variables. BL rises mainly due to poor tissue perfusion and anaerobic glycolysis associated with shock, providing an indicator of both the severity of disease and its prognosis. A hand-held lactate meter, Accusport, provides a rapid (60 seconds), inexpensive dry-chemical-based determination of BL. This trial evaluated the Accusport's ability to provide BL data as an adjunct to the initial clinical evaluation of horses with colic. The accuracy of the Accusport was tested by evaluation of its interchangeability with the benchmark enzymatic kit evaluation of BL in a trial using data collected firstly from 10 clinically normal control horses and subsequently from 48 horses presented with signs of colic. The BL values were recorded together with the clinical variables of heart rate (HR), capillary refill time (CRT), haematocrit (Hct), and pain character and severity on the initial assessment of the colic horses. Information regarding choice of therapeutic management (medical or surgical) and eventual case outcome (full recovery or died/euthanased) was recorded. The Accusport was found to be interchangeable with the enzymatic kit for recording BL values in colic horses with BL <10 mmol/ , which is within the BL range associated with survival. The interchangeability of an additional, laboratory-based wet chemical assay for BL, the Stat 7 was simultaneously evaluated for the colic and control horses. The Stat 7 was found to be interchangeable with the enzymatic kit for BL determination of colic horses. No linear associations between BL values with HR, CRT, Hct or pain assessment were observed. No relationship with either selection of therapeutic method or eventual case outcome was observed. All horses with BL >8 mmol/ died or were euthanased.

Model independent determination of GEn from the reaction

1988 ◽  
Vol 206 (2) ◽  
pp. 187-189 ◽  
Author(s):  
E.L. Tomusiak ◽  
H. Arenhövel
Keyword(s):  
Independent Determination ◽  
Model Independent

scholarly journals A simplified empirical method for determination of aerosol hygroscopicity and composition

2010 ◽  
Vol 10 (10) ◽  
pp. 23627-23656
Author(s):  
C. H. Chan ◽  
A. Y. S. Cheng ◽  
A. Viseu
Keyword(s):  
Atmospheric Aerosols ◽  
Climate Model ◽  
Empirical Method ◽  
Radiation Budget ◽  
Cloud Formation ◽  
Monthly Variation ◽  
Aerosol Composition ◽  
Remote System ◽  
Aerosol Hygroscopicity

Abstract. Atmospheric aerosols have substantial influence on the Earth's radiation budget, visibility, cloud formation and precipitation. The aerosol hygroscopicity and the composition of aerosols are of vital importance for solar radiation budget calculation, cloud formation mechanism, and measurement of aerosol spatiotemporal distribution through remote sensing, such as Lidar, MODIS and sun/star photometer. In this paper, hourly averaged records of humidity, visibility and aerosol concentration, conducted in Macao, P.R.C. from 1 February 2006 to 31 December 2008 (LT), are used to estimate aerosol hygroscopicity and composition with a simplified empirical method. The result of monthly variation of aerosol hygroscopicity indicates the important role of aerosol composition on optical properties, which is in agreement with the previous study. This aerosol composition pattern is also consistent with the Asiatic Monsoon pattern and vicinity, such as Hong Kong. The monthly variation of aerosol hygroscopicity and composition also shows the necessity to consider such a factor for the aerosols monitoring by remote system and aerosols forcing simulated by climate model.

scholarly journals Determination of high sensitive cardiac troponin I 99th percentile upper reference limits in a healthy Pakistani population

2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Kulsoom Bahadur ◽  
Aamir Ijaz ◽  
Momin Salahuddin ◽  
Aftab Alam
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Laboratory Data ◽  
Cardiac Troponin I ◽  
Medical Institute ◽  
Pakistani Population ◽  
Reference Limits ◽  
Males And Females ◽  
Gender Specific

Objective: This study aims to establish the 99th percentile upper reference limits of high sensitive cardiac troponin I in a healthy Pakistani population. Methods: It was an Observational cohort study carried out in Department of Chemical Pathology and Endocrinology Rehman Medical Institute Peshawar, over the period of one year (January 2019- December 2019). Total 299 cardio-healthy males and females were interviewed and taken past medical history. Based on history, clinical examination, echocardiogram and laboratory data including results of estimated glomerular filtration rate (eGFR) and N-terminal pro-B-type natriureteric peptide (NT-proBNP), subjects with possible subclinical diseases were excluded. High Sensitive Cardiac Troponin I (hs-cTtrop I) was analysed on Abbot ARCHITECT STAT ci8200 using chemiluminescent immunoassay technique. The 99th percentile upper reference limit (URL) of hs-cTtrop I was determined using a non-parametric statistic, while gender specific results were compared. Results: In this study, 178 males (59.5%) and 121 females (40.5%) were included. The median Interquartile ranges (IQR) of age was 57 (11.6) for males and 56 (13) for females. The 99th percentile URL hs-cTtrop I was found to be 33.9 ng/L, while gender specific values were 38.41ng/L and 15.73ng/L for males and females, respectively (p= 0.0045). Conclusion: High sensitivity cardiac troponin I 99th percentile URL in our study population was found to be 33.9 ng/L with gender specific values being 38.41 ng/L and 15.73ng/L for males and females respectively. Troponin I in males was substantially high in comparison with females. doi: https://doi.org/10.12669/pjms.36.6.2328 How to cite this:Bahadur K, Ijaz A, Salahuddin M, Alam A. Determination of high sensitive cardiac troponin I 99th percentile upper reference limits in a healthy Pakistani population. Pak J Med Sci. 2020;36(6):---------. doi: https://doi.org/10.12669/pjms.36.6.2328 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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