Incomplete determination of a measure of quality in a series of experiments

1956 ◽  
Vol 48 (1) ◽  
pp. 124-128
Author(s):  
D. J. Finney ◽  
Ø. Nissen
Keyword(s):  
Field Experiment ◽  
Quality Factor ◽  
Experimental Error ◽  
Dry Matter ◽  
Total Expenditure ◽  
Series Of Experiments ◽  
Measure Of Performance

Often the ultimate measure of performance in a field experiment is the product of a gross weight and a factor relating to quality, as when yield of dry matter is determined from gross yield and percentage dry matter. Since the factor is usually much less variable than the gross yield, yet relatively troublesome and expensive to determine, the practice of making independent estimates of it in every experiment involves diversion of an appreciable part of the total expenditure to a measurement whose inaccuracy will affect only slightly the final experimental error.Proposals are made for determining the quality factor on only a fraction of all the experiments of one series and applying the averages to the gross yields of others in the same series; formulae and tables relating to the most economic ratio of incompletely to completely recorded experiments are presented.

The Effect of Stress and Warfarin on the Adrenal Gland in Relation to Spontaneous Hemorrhage, as Judged by Measurement of Adrenal Ascorbic Acid and Serum Corticosterone

1971 ◽  
Vol 26 (02) ◽  
pp. 275-288 ◽  
Author(s):  
S Chattopadhyay ◽  
D. D Johnson ◽  
G. J Millar ◽  
L. B Jaques
Keyword(s):  
Ascorbic Acid ◽  
Acid Concentration ◽  
Ascorbic Acid Concentration ◽  
Corticosterone Concentration ◽  
Serum Corticosterone ◽  
Spontaneous Hemorrhage ◽  
Combined Action ◽  
Series Of Experiments ◽  
Pituitary Adrenal Axis

SummaryRats were subjected to the following procedures: No treatment, Stressor (10% NaCl i.p.), Warfarin for 7 days, Stressor followed by Warfarin; and groups were sacrificed at intervals for assessment of spontaneous hemorrhage and of adrenal ascorbic acid concentration. There was no hemorrhage in the no treatment and stressor groups; some hemorrhage in the warfarin group; profound hemorrhage with Warfarin + Stressor. The adrenal ascorbic acid concentration was found to be lower, 8 h and again 5 days after stress, and remained lower in the warfarin + stress animals. Warfarin had no effect on adrenal ascorbic acid level.In another series of experiments in which the stress consisted of an electric current to the cage floor for 6 sec over 15 min, rats were sacrificed daily for determination of serum corticosterone concentration and occurrence of spontaneous hemorrhage. There was a statistically significant increase of serum corticosterone concentration with stress, warfarin and combined warfarin and stress treatments (P< 0.001 for all three variables). There was a significant correlation (r = 0.96 and 0.89, P< 0.01) for serum corticosterone concentration with hemorrhage score and incidence of hemorrhage in stressed rats receiving warfarin, but not in those receiving only warfarin. The results indicate an activation, rather than an exhaustion, of the pituitary-adrenal axis during the combined action of anticoagulant and stress, which results in the development of spontaneous hemorrhage.

Stoichiometric Determination of Graphite Intercalation Compounds Using Rutherford Backscatiering Spectrometry

1983 ◽  
Vol 27 ◽  
Author(s):  
L. Salamanca-Riba ◽  
B.S. Elman ◽  
M.S. Dresselhaus ◽  
T. Venkatesan
Keyword(s):  
Experimental Error ◽  
Rutherford Backscattering Spectrometry ◽  
Rutherford Backscattering ◽  
Intercalation Compounds ◽  
Graphite Intercalation Compounds ◽  
X Ray ◽  
Donor And Acceptor ◽  
Graphite Intercalation ◽  
Non Destructive

ABSTRACTRutherford backscattering spectrometry (RBS) is used to characterize the stoichiometry of graphite intercalation compounds (GIC). Specific application is made to several stages of different donor and acceptor compounds and to commensurate and incommensurate intercalants. A deviation from the theoretical stoichiometry is measured for most of the compounds using this non-destructive method. Within experimental error, the RBS results agree with those obtained from analysis of the (00ℓ) x-ray diffractograms and weight uptake measurements on the same samples.

High phosphorus concentrations in seed of wheat and annual medic are related to higher rates of dry matter production of seedlings and plants

1988 ◽  
Vol 28 (6) ◽  
pp. 765 ◽  
Author(s):  
MDA Bolland ◽  
MJ Baker
Keyword(s):  
Triticum Aestivum ◽  
Field Experiment ◽  
Western Australia ◽  
Dry Matter ◽  
Field Experiments ◽  
Medicago Polymorpha ◽  
P Concentration ◽  
Pot Experiments ◽  
Matter Production ◽  
Burr Medic

Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.

W. T. Astbury and Ross G. Harrison: the search for the molecular determination of form in the developing embryo

1980 ◽  
Vol 35 (2) ◽  
pp. 195-219 ◽  
Keyword(s):  
Royal Society ◽  
Limb Bud ◽  
Amphibian Embryo ◽  
X Ray ◽  
Biological Phenomena ◽  
Biology I ◽  
Series Of Experiments ◽  
Molecular Patterns ◽  
Molecular Determination

Amongst the Fellows elected to the Royal Society in 1941 were W. T. Astbury for his studies using X-ray analysis to study the structures of natural fibres, and amongst the Foreign Members elected that year was Ross G. Harrison for his contributions to embryology. Astbury and Harrison were very different in temperament, and worked in very different fields on either side of the Atlantic, yet they were united in their approach to the study of biological phenomena. Both Astbury and Harrison believed that the organization and form of biological materials whether wool fibres or the limb-bud in an amphibian embryo depended on molecular structure and pattern. Moreover both were concerned with dynamic aspects of form; Astbury’s greatest achievement was to demonstrate the dynamic, reversible folding and stretching of proteins in the k-m-e-f group, and Harrison looked to changing molecular patterns to account for changing symmetries in the developing embryo. It was this common approach that brought them together and led to Harrison spending a brief month in Leeds where they and K. M. Rudall performed what have been described as ‘truly progressive experiments in molecular biology’. I believe this short series of experiments illuminates the character and work of both Harrison and Astbury and illustrates the difficulties, practical and conceptual, in carrying out ‘progressive experiments’. I shall begin by reviewing briefly the embryological background of the time before going on to discuss in detail the approaches of Harrison and Astbury to their work and the outcome of their collaboration.

IV. On the determination of the scale value of a Thomson’s quadrant electrometer used for registering the variations in atmospheric electricity at the Kew Observatory

1878 ◽  
Vol 27 (185-189) ◽  
pp. 356-361 ◽  
Keyword(s):  
Atmospheric Electricity ◽  
Series Of Experiments

The Meteorological Council, being desirous of discussing the photographic traces produced by their electrograph at the Kew Observatory some time since, requested the Kew Committee to institute a series of experiments, with the view of determining the scale value of the instrument, in order to prepare a suitable scale for measuring the curves. The Kew Committee, at their meeting in November, entrusted the matter to me, and accordingly, having obtained the loan of a battery of 300 Bunsen cells, some preliminary experiments were made, which showed that the greatest potential which could be obtained with them was very inadequate for the purpose.

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