Estimation of the composition of broiler carcasses from their specific gravity

An experiment was conducted to quantify the relationships between broiler carcass specific gravity and chemical composition (percentage moisture, percentage lipid, percentage protein). Carcasses of widely varying compositions were produced by feeding several dietary protein and energy combinations (52 to 64% moisture, 0.6 to 2.5% ash, 1.6 to 11.7% lipid, and 4.9 to 8.0% nitrogen). Very strong relationships were found between percentage moisture and percentage lipid (r = -0.969) and percentage moisture and percentage N (r = 0.968). Strong relationships were found between specific gravity and percentage lipid (r = -0.872) and specific gravity and percentage N (r = 0.857). Specific gravity is recommended as a means to estimate carcass fat in broiler chickens.     

Some pitfalls in curve-fitting and how to avoid them: a case in point

When curve-fitting is used to support a complex nonlinear model containing several exponential terms, some of which have closely-spaced time constants, a particular burden of proof must be assumed. Most important, the uniqueness of the solution must be explored and discussed. Statistical tests for the degree of error and independence of the parameters should be provided, as well as information relating to the steps actually used in the fitting procedures. As an example of the need for the procedures we recommend in this communication, we have chosen an important case in point that has been published recently, and which deals with the kinetics of electron transfer from fully-reduced cytochrome oxidase to O2, analyzed by the method of SVD-based least squares. The problems we deal with in this case are applicable to a wide variety of other cases that involve curve-fitting to mathematical models.     

Untersuchungen über die Bestimmung der Zähigkeit von Bauteilen im Apparatebau durch Messungen an Modellbehältern von praxisähnlicher Größe. Theoretische Überlegungen und Vervollständigung der Auswertungen der Meßergebnisse

Research into the Determination of the ductility of structural Elements in plant construction by Measurements on model Vessels of near industrial Size — Theoretical studies and completion of the exploitation of test results The deformation of pressure vessels with nozzles is investigated at various temperatures. For this purpose, the surface strains at the interesting spots, the increase of volume, and other quantities are measured in dependence on the internal pressure. The stresses are calculated — by means of the stress-strain relations for the elastic or plastic strain — from the surface strains and the yield strength, and they are shown in diagrams together with the effective strain. Setting the internal pressure and the radii of curvature in the membrane equation yields a linear dependence of the two average normal stresses on each other. By comparison to the calculated stresses it is possible to conclude to the bending moments in the wall. The results coincide with the experimentally observed origins of the cracks. Moreover at various temperatures the deformation of the pressure vessels is compared to the results of uniaxial tensile tests, and the expediency of other tests is discussed.     

Relationship between the catalytic sites of human bifunctional IMP synthase

A two-compartment system for approximating five successive steady-state levels of gadopentetate dimeglumine (Gd-DTPA) concentration in pigs was developed. The method of calculating Gd-DTPA concentration was based on a simultaneous reference determination of 99mTc-DTPA. Experimental and theoretical results showed a steady state after 25 min. The nuclear magnetic resonance (NMR) relaxivities of Gd-DTPA were determined in vivo in pig kidneys during steady-state levels. T1 relaxivity (R1) and T2 relaxivity (R2) in the kidney cortex were found to be 1.1+/-0.03 and 2.0+/-0.2 (s(-1) mM(-1)), respectively. R1 and R2, in in vitro human plasma solutions at 25 degrees C were 5.3+/-0.02 and 5.8+/-0.06 s-1 mM-1 and at 37 degrees C 4.3+/-0.04 and 4.9+/-0.01 s(-1) mM(-1). Thus, the in vivo relaxivities were reduced 3.9 and 2.5 times for R1 and R2, respectively, compared to the in vitro relaxivities. This marked difference in relaxivities between tissue and plasma may be the result of the difference in steric relations. In plasma, the mobility and distribution of the Gd-DTPA complex are unrestricted, whereas they may be reduced in the tissues because of the close proximity to the cell wall, to the proteins and to other extracellular elements and compartments.     

The significance of p53 autoantibodies in the serum of patients with breast cancer

Serum p53 autoantibodies were studied in 82 patients with Stage 1 or 2 breast cancer using an ELISA assay. Tissue expression of p53 in these patients was also examined. High levels of serum p53 autoantibodies were detected in 48% (39/82) patients, while 23% (19/82) were tissue positive. Patients with high serum p53 autoantibodies levels were not significantly different to those with low levels with respect to, tissue p53, tumour grade, size, stage or oestrogen receptor status. Tissue immunoreactivity for p53 was significantly associated with tumour grade and negative oestrogen receptor status. Patients in both groups were followed for a median of over five years but the presence of p53 autoantibodies in serum was not prognostic with respect to disease free interval or survival. In this study detection of p53 autoantibodies in serum does not correlate with any of the usual tumour related prognostic factors, nor does it correlate with clinical outcome.