The effect of transection of the duck blastoderm on the orientation of the embryo

Development ◽  
1968 ◽  
Vol 20 (3) ◽  
pp. 237-245
Author(s):  
Teresa Rogulska
Keyword(s):  
Large Percentage ◽  
Control Material ◽  
Extensive Information

Von Baer (1828) formulated a rule according to which the cephalo-caudal axis is perpendicular to the long axis of the shell, and the head of the embryo is directed forwards when the egg is placed with the blunt end to the left. This law has been checked in several species of bird: hen, duck, pigeon, goose, turkey (see Clavert, 1960, for references) and quail (Fargeix, 1963, 1964). Embryos obeying von Baer's rule were found to constitute the most numerous class, but considerable interspecific as well as intraspecific differences were observed. The studies by Lutz (1949) supply extensive information on the regulative capacities of the duck blastoderm, but do not provide any data concerning the determination of the presumptive axis of the blastoderm. The control material of this author revealed a large percentage of embryos obeying von Baer's rule. In consequence Lutz defines transections perpendicular to the long axis of the shell as ‘parallel to the presumptive axis’, and transections parallel to the long axis as ‘perpendicular to the presumptive axis’.

scholarly journals Comparison of Amerlex, NML, and Ames Total Thyroxine and Triiodothyronine Radioimmunoassay Kits

1982 ◽  
Vol 19 (2) ◽  
pp. 104-107 ◽  
Author(s):  
Timothy J Wilke ◽  
Patricia A Turnbull
Keyword(s):  
Quality Control ◽  
Good Accuracy ◽  
Clinical Decision ◽  
Quality Control Material ◽  
Control Material ◽  
Total Triiodothyronine ◽  
Total Thyroxine ◽  
Precision And Accuracy

An evaluation of the Amerlex system for determination of total thyroxine (T4) and total triiodothyronine (T3) is described. The within- and between-batch precisions were acceptable, and analyses of quality control material and linearity studies demonstrated good accuracy at the clinical decision levels. The correlations obtained with NML and Ames T4 and T3 kit methods were highly significant. The Amerlex T4 and T3 methods are rapid, technically simple, and, coupled with excellent precision and accuracy, present significant advantages.

Feasibility of rat hair as a quality control material for the determination of methamphetamine and amphetamine in human hair

2011 ◽  
Vol 34 (4) ◽  
pp. 593-598 ◽  
Author(s):  
Sooyeun Lee ◽  
Yonghoon Park ◽  
Jihyun Kim ◽  
Sanghwan In ◽  
Hwakyung Choi ◽  
...  
Keyword(s):  
Quality Control ◽  
Human Hair ◽  
Quality Control Material ◽  
Control Material

scholarly journals The method of pneumoperitoneum in the diagnosis and determination of the operability of cancer of the upper stomach

2021 ◽  
Vol 43 (2) ◽  
pp. 18-24
Author(s):  
E. G. Kucherkov
Keyword(s):  
Large Percentage ◽  
Surrounding Tissue

Although radical operations for cancer of the upper part of the stomach have become widespread, a large percentage of operations for such lesions ends with a trial laparotomy due to the extensive spread of the tumor to the surrounding tissue organs, which has not been clarified before the operation.

Investigation of the Thermal Conductivity of Rubber

1938 ◽  
Vol 11 (2) ◽  
pp. 359-371 ◽  
Author(s):  
L. Frumkin ◽  
Yu Dubinker
Keyword(s):  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Natural Rubber ◽  
Considerable Increase ◽  
Large Percentage ◽  
K Value ◽  
Synthetic Rubber ◽  
Coefficient Of Thermal Conductivity

Abstract 1. The apparatus for the determination of the coefficients of thermal conductivity which is described is satisfactory for the investigation of rubber mixtures. 2. A review of the results of the determinations of K values of various mixtures leads to the following conclusions: (a) The thermal conductivity of rubber mixtures containing synthetic rubber is greater than that of mixtures containing natural rubber. (b) The addition of zinc oxide even in considerable quantities to rubber mixtures containing a large percentage (55 per cent) of carbon black does not substantially increase thermal conductivity. (c) In the case of carcass mixtures a considerable increase in the coefficient of thermal conductivity is observed when the content of zinc oxide is increased from 7.5 to 15 per cent by weight; on further increase in the zinc oxide K increases but little. (d) The K value of carcass mixtures before vulcanization is smaller than that of the same mixtures after vulcanization by an average of 23 per cent. (e) The thermal conductivity of uncured tread mixtures is the same as that of vulcanized mixtures. (f) The coefficient of vulcanization has no effect on the K value of unloaded mixtures and mixtures containing fillers. (g) The K value of rubber mixtures increases sharply with addition up to 60 per cent by volume of fillers with good thermal conductivity (zinc oxide and graphite), but only slowly with the addition of fillers of medium thermal conductivity (carbon black). In other words, the curve of the relation between the coefficient of thermal conductivity and the percentage by volume of graphite and of zinc oxide is convex to the filler axis and is concave in the case of carbon black.

Lyophilized bovine hemoglobin as a possible reference material for the determination of hemoglobin derivatives in human blood

1998 ◽  
Vol 44 (11) ◽  
pp. 2331-2339 ◽  
Author(s):  
Bart H A Maas ◽  
Anneke Buursma ◽  
Rob A J Ernst ◽  
Anton H J Maas ◽  
Willem G Zijlstra
Keyword(s):  
Quality Control ◽  
Bovine Hemoglobin ◽  
Wavelength Selection ◽  
Quality Control Material ◽  
Hemoglobin Solution ◽  
Control Material ◽  
Hemoglobin Derivatives ◽  
Target Values ◽  
Specific Factors

Abstract We investigated the suitability of a lyophilized bovine hemoglobin (LBH) preparation containing various fractions of oxyhemoglobin (O2Hb), carboxyhemoglobin (COHb), and methemoglobin (MetHb) for quality assessment in multicomponent analysis (MCA) of hemoglobin derivatives. It was demonstrated that a stable preparation of these components after reconstitution yields a hemoglobin solution that is spectrophotometrically equivalent with a fresh bovine hemoglobin solution. The preparation was found to be stable for at least 1 year when it is kept at 2–8 °C and for 1 h after reconstitution. We determined the fractions of O2Hb, COHb, and MetHb of several LBH preparations, using the complete spectra of 480–650 nm with 2-nm intervals and absorptivities as determined for pure LBH solutions. A field trial involving various types of multiwavelength hemoglobin photometers showed the suitability of LBH as a quality-control material. Computer models of the various common multiwavelength hemoglobin photometers may be useful for establishing more accurate target values of LBH preparations for each type of photometer and for studying the importance of the influence of specific factors such as wavelength selection, absorptivity values, and interfering dyes.

Joint petrophysical inversion of electromagnetic and full-waveform seismic data

Geophysics ◽  
2012 ◽  
Vol 77 (3) ◽  
pp. WA3-WA18 ◽  
Author(s):  
Guozhong Gao ◽  
Aria Abubakar ◽  
Tarek M. Habashy
Keyword(s):  
Bulk Modulus ◽  
Seismic Data ◽  
Joint Inversion ◽  
Large Percentage ◽  
Rock Matrix ◽  
Petrophysical Parameters ◽  
Electromagnetic Data ◽  
Full Waveform ◽  
Fluid Saturation

Accurate determination of reservoir petrophysical parameters is of great importance for reservoir monitoring and characterization. We developed a joint inversion approach for the direct estimation of in situ reservoir petrophysical parameters such as porosity and fluid saturations by jointly inverting electromagnetic and full-waveform seismic measurements. Full-waveform seismic inversions allow the exploitation of the full content of the data so that a more accurate geophysical model can be inferred. Electromagnetic data are linked to porosity and fluid saturations through Archie’s equations, whereas seismic data are linked to them through rock-physics fluid-substitution equations. For seismic modeling, we used an acoustic approximation. Sensitivity studies combined with inversion tests show that seismic data are mainly sensitive to porosity distribution, whereas electromagnetic data are more sensitive to fluid-saturation distribution. The separate inversion of electromagnetic or seismic data is highly nonunique and thus leads to great ambiguity in the determination of porosity and fluid saturations. In our approach, we used a Gauss-Newton algorithm equipped with the multiplicative regularization and proper data-weighting scheme. We tested the implemented joint petrophysical inversion method using various synthetic models for surface and crosswell measurements. We found that the joint inversion approach provides substantial advantage for an improved estimation of porosity and fluid-saturation distributions over the one obtained from the separate inversion of electromagnetic and seismic data. This advantage is achieved by significantly reducing the ambiguity on the determination of porosity and fluid saturations using multiphysics measurements. We also carried out a study on the effects of using inaccurate petrophysical transform parameters on the inversion results. Our study demonstrated that up to 20% errors in the saturation and porosity exponents in Archie’s equations do not cause significant errors in the inversion results. On the other hand, if the bulk modulus and density of the rock matrix have a large percentage of errors (i.e., more than 5%), the inversion results will be significantly degraded. However, if the density of the rock matrix has an error of less than 2%, the joint inversion can tolerate a large percentage of errors in the bulk modulus of the rock matrix.

scholarly journals DNA-based determination of suitable pollinating cultivars for the pear cultivar 'Carola' (Pyrus communis)

2007 ◽  
Vol 13 (1) ◽  
Author(s):  
H. Nybom ◽  
J. Sehic ◽  
H. Mattisson
Keyword(s):  
Fruit Set ◽  
Large Percentage ◽  
Maximum Distance ◽  
Pollen Transfer ◽  
Long Distance ◽  
Maternal Parent ◽  
Pear Cultivar ◽  
Pear Orchard ◽  
S Allele

Pollen-limited fruit set has long been suspected in some relatively low-yielding orchards with the Swedish pear cultivar 'Carola'. Fruit was therefore harvested on 23 'Carola' trees in a commercial pear orchard. The seeds were germinated and five seedlings from each tree were sampled to determine which of the surrounding cultivars had been the most successful pollinators. Leaves of 'Carola', the 7 putative pollinating cultivars and the 115 seedlings were analysed with 6 RAPD primers. By comparison of the band patterns, paternity could be ascertained for 74 seedlings. The by far most successful pollinator was 'Clara Frijs' which had sired approx. half of the seedlings, followed by 'Herzogin Elsa', `Skanskt Sockerpiiron', 'Alexandre Lucas', 'Coloree de Juillet' and 'Doyenne du Cornice'. The latter is the maternal parent of 'Carola', and these two cultivars must therefore share one S-allele and hence can only be semi-compatible. In addition, 6% of the seedlings were in all likelihood derived from selling_ since they showed no bands that did not occur also in 'Carola'. Maximum distance between 'Carola' trees and suitable pollinators should not exceed 15-20 tn. Longer distances may produce a serious dearth of compatible pol­len as evidenced by the large percentage of seedlings derived either from selling. (25%) or from long-distance (> 40 m) pollen transfer (25%) when 'Carola' trees were surrounded by non-preferred pollinators.

Microwave-Assisted Extraction and Quantitative LC/ID-MS Measurement of Total Choline and Free Carnitine in Food Standard Reference Materials

2012 ◽  
Vol 95 (5) ◽  
pp. 1479-1486 ◽  
Author(s):  
Melissa M Phillips ◽  
Lane C Sander
Keyword(s):  
Infant Formula ◽  
Reference Materials ◽  
Free Carnitine ◽  
Soy Flour ◽  
Standard Reference Materials ◽  
Control Material ◽  
Microwave Assisted ◽  
Food Standard ◽  
Egg Powder

Abstract The Stakeholder Panel on Infant Formula and Adult Nutritionals of AOAC INTERNATIONAL has declared both choline and carnitine to be priority nutrients in infant formulas, and ongoing efforts exist to develop or improve Official Methods of AnalysisSM for these nutrients. As a result, matrix-based certified reference materials are needed with assigned values for these compounds. In this work, traditional acid and enzymatic hydrolysis procedures were compared to microwave-assisted acid hydrolysis, and conditions optimized to provide complete sample hydrolysis and recovery of total choline from four food standard reference materials (SRMs): whole milk powder, whole egg powder, infant formula, and soy flour. The extracts were analyzed using LC on a mixed-mode column (simultaneous RP and ion exchange) with isotope dilution-MS detection to achieve simultaneous quantification of total choline and free carnitine. Total choline has been determined in these four food matrixes with excellent precision (0.65 to 2.60%) and accuracy, as confirmed by use of SRM 1849 Infant/Adult Nutritional Formula as a control material. Free carnitine has been determined in two of these food matrixes with excellent precision (0.69 to 2.19%) and accuracy, as confirmed by use of SRM 1849 Infant/Adult Nutritional Formula as a control material. Limitations in simultaneous determination of total choline and free carnitine resulted from extreme differences in concentration of the two components in egg powder and soy flour (at least three orders of magnitude). Samples required dilution to prevent poor LC peak shape, which caused decreased precision in the determination of low concentrations of free carnitine. Despite this limitation, the described method yields results comparable to current AOAC Official Method 999.14 Choline in Infant Formula, with a decrease of more than 2 h in sample preparation time.

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