Statistical Methods—Applied to Experiments in Agriculture and Biology
07 Apr 1939-Science (American Association for the Advancement of Science)-Vol. 89, Iss: 2310, pp 317-318
About: This article is published in Science.The article was published on 1939-04-07. It has received 222 citations till now.
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TL;DR: The present paper is an account of some of the investigations on the biology of the perch in Windermere, which are being conducted in connexion with a trap-fishery experiment, which revealed the relative complexity of the interrelationships of length, weight and condition.
Abstract: The present paper is an account of some of the investigations on the biology of the perch (Perca fluviatilis Linn.) in Windermere, which are being conducted in connexion with a trap-fishery experiment (Worthington, 1950). This experiment is mainly a study of populations, but it has been necessary simultaneously to investigate the general biology of the perch, particularly the growth and related aspects. The computation of a formula to express the length,weight relationship and provide a means of interconverting measurements of length and weight, revealed the relative complexity of the interrelationships of length, weight and condition. Condition in turn was found to be correlated with the seasonal changes in gonad development and growth, and the importance of the effect of stomach contents on weight had also to be assessed. It was decided, therefore, to combine these separate but interrelated aspects in one paper. The main part of the paper is devoted to the questions of length-weight relationship and condition. A brief review of the fundamental bases for the concepts of length-weight relationship and condition and of some of the methods of analysis of length-weight data precedes an account of the application of the chosen methods to the present material and its results. This is followed by an account of seasonal changes in gonad weights. A brief account is then given of the rather scanty data available on the weight of stomach contents. The seasonal changes in condition are then described and, finally, some of the results are summarized, combined and discussed as a picture of the seasonal cycle in the Windermere perch. In the statistical analysis of the length-weight relationship the data for only one group of fish are given in full (Tables i and 2) as an example of the method of computation used for all the groups. Again, in the section on seasonal changes in gonad weight and condition Figs. 2-7 are based partly on tables of data which are not published. The full tables have been deposited with the Freshwater Biological Association, from whom copies can be obtained.
3,332 citations
01 Jan 1971
TL;DR: A B S T R A C T Heterologous antiserum was prepared in rabbits against highly purified human antihemophilic factor (AHF, factor VIII) as mentioned in this paper.
Abstract: A B S T R A C T Heterologous antiserum was prepared in rabbits against highly purified human antihemophilic factor (AHF, factor VIII). This antiserum blocked the clot-promoting properties of AHF and, when suitably absorbed, formed a single precipitin line against AHF upon immunoelectrophoresis. Material antigenically similar to normal AHF was detected in normal amounts in plasma concentrates in each of 22 patients with classic hemophilia, in a patient with an acquired circulating anticoagulant against AHF, and in a patient with deficiencies both of AHF and proaccelerin (factor V). AHF-like antigen was present in normal human serum. In contrast, material antigenically related to AHF was found in decreased amounts in the concentrates prepared from the plasma of 11 patients with von Willebrand's disease. The experiments described suggest that von Willebrand's disease is a disorder in which a true deficiency of AHF exists. Whether the AHF-like material
555 citations
TL;DR: The hypocholesterolemic effect of polyunsaturated fat was associated with total fecal sterol excretion twice greater than the amount of cholesterol calculated to leave the plasma, which suggested possible loss of cholesterol from the tissues as well.
Abstract: Six normal men were fed formula diets containing either highly saturated fat (cocoa butter, iodine value 32) or polyunsaturated fat (corn oil, iodine value 125). The sterol balance technique was used to compare the changes in serum cholesterol concentration with the excretion of fecal steroids. The method used for the analysis of fecal steroids was chemical, with a final identification and quantification by gas-liquid chromatography. It was confirmed that the chemical method for fecal steroid analysis was accurate and reproducible. The three dietary periods were each 3 wk in length. In sequence, cocoa butter (period I), corn oil, and cocoa butter (period III) were fed at 40% of the total calories. All diets were cholesterol free, contained similar amounts of plant sterols, and were identical in other nutrients. Corn oil had a hypocholesterolemic effect. Mean serum cholesterol concentrations were 222 mg/100 ml (cocoa butter, period I), 177 during corn oil, and 225 after the return to cocoa butter. Individual fecal steroids were determined from stools pooled for 7 days. Both neutral steroids and bile acids were altered significantly by dietary polyunsaturated fat. The change in bile acid excretion was considerably greater than the change in neutral steroids. Corn oil caused a greater fecal excretion of both deoxycholic and lithocholic acids. The total mean excretion (milligrams per day) of fecal steroids was 709 for cocoa butter (period I), 915 for corn oil, and 629 for the second cocoa butter period. The enhanced total fecal steroid excretion by the polyunsaturated fat of corn oil created a negative cholesterol balance vis-a-vis the saturated fat of cocoa butter. The hypocholesterolemic effect of polyunsaturated fat was associated with total fecal sterol excretion twice greater than the amount of cholesterol calculated to leave the plasma. This finding suggested possible loss of cholesterol from the tissues as well.
259 citations
Cites methods from "Statistical Methods—Applied to Expe..."
...Statistical analyses were performed by standard methods (19)....
[...]
TL;DR: It is concluded that glucocorticoids increase plasma glucagon concentration in the basal state and in response to protein ingestion or aminogenic stimulation occurs in the face of obesity and persists in chronic hypercorticism.
Abstract: Plasma concentrations of glucagon, insulin, glucose, and individual plasma amino acids were measured in normal nonobese and obese subjects before and after 3 days of dexamethasone treatment (2 mg/day) and in patients with Cushing's syndrome. The subjects were studied in the basal postabsorptive state and following the infusion of alanine (0.15 g/kg) or ingestion of a protein meal. In nonobese subjects dexamethasone treatment resulted in a 55% increment in basal glucagon levels and in a 60-100% increase in the maximal glucagon response to alanine infusion or protein ingestion. In obese subjects, basal glucagon rose by 110% following dexamethasone, while the response to alanine increased fourfold. In patients with Cushing's syndrome basal glucagon levels were 100% higher and the glucagon response to alanine infusion was 170% greater than in normal controls.Dexamethasone treatment in normal subjects resulted in a 40% rise in plasma alanine concentration which was directly proportional to the rise in basal glucagon. The remaining 14 amino acids were unchanged. In the patients with Cushing's syndrome alanine levels were 40% higher than in normal controls and were directly proportional to basal glucagon concentrations. No other plasma amino acids were significantly altered in the group with Cushing's syndrome. It is concluded that (a) glucocorticoids increase plasma glucagon concentration in the basal state and in response to protein ingestion or aminogenic stimulation; (b) this effect of glucocorticoids occurs in the face of obesity and persists in chronic hypercorticism; (c) hyperalaninemia is a characteristic of acute and chronic glucocorticoid excess, and may in turn contribute to steroid-induced hyperglucagonemia; and (d) increased alpha cell secretion may be a contributory factor in the gluconeogenic and diabetogenic effects of glucocorticoids.
247 citations
Cites methods from "Statistical Methods—Applied to Expe..."
...In comparing the group with Cushing's syndrome to the healthy nonobese group, the unpaired t test was used (19)....
[...]
...For the statistical analyses, the paired t test (19) was employed in comparing observations pre- and post-dexamethasone treatment in the healthy nonobese and obese groups, each subject thus serving as his own control....
[...]
TL;DR: Sodium and soluble organic solutes accumulation in the roots as a result of salt stress appeared to play an important role in the acclimation to salt stress of the maize genotypes studied, suggesting that they could be used as physiological markers during the screening for salt tolerance.
Abstract: Seeds from eight different maize genotypes (BR3123, BR5004, BR5011, BR5026, BR5033, CMS50, D766 and ICI8447) were sown in vermiculite, and after germination they were transplanted into nutrient solution or nutrient solution containing 100 mmolL-1 of NaCl and placed in a greenhouse During the experimental period plant growth (dry matter, shoot to root dry mass ratio, leaf area, relative growth rate, and net assimilation rate), leaf temperature, stomatal conductance, transpiration, predawn water potential, sodium, potassium, soluble amino acids and soluble carbohydrate contents were determined in both control and salt stressed plants of all genotypes studied Salt stress reduced plant growth of all genotypes but the genotypes BR5033 and BR5011 were characterized as the most salt-tolerant and salt-sensitive, respectively Stomatal response of the salt-tolerant genotype was not affected by salinity Among the studied parameters, shoot to root dry mass ratio, leaf sodium content and leaf soluble organic solute content showed no relation with salt tolerance, ie, they could not be considered as good morpho-physiological markers for maize salt tolerance In contrast, sodium and soluble organic solutes accumulation in the roots as a result of salt stress appeared to play an important role in the acclimation to salt stress of the maize genotypes studied, suggesting that they could be used as physiological markers during the screening for salt tolerance
206 citations
Cites methods from "Statistical Methods—Applied to Expe..."
...The means and their standard deviations or the Tukey test were used for comparing different treatments, and the coefficient of correlation (r) and the F-test were used for studying correlation between variables (Snedecor, 1956)....
[...]
References
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TL;DR: The present paper is an account of some of the investigations on the biology of the perch in Windermere, which are being conducted in connexion with a trap-fishery experiment, which revealed the relative complexity of the interrelationships of length, weight and condition.
Abstract: The present paper is an account of some of the investigations on the biology of the perch (Perca fluviatilis Linn.) in Windermere, which are being conducted in connexion with a trap-fishery experiment (Worthington, 1950). This experiment is mainly a study of populations, but it has been necessary simultaneously to investigate the general biology of the perch, particularly the growth and related aspects. The computation of a formula to express the length,weight relationship and provide a means of interconverting measurements of length and weight, revealed the relative complexity of the interrelationships of length, weight and condition. Condition in turn was found to be correlated with the seasonal changes in gonad development and growth, and the importance of the effect of stomach contents on weight had also to be assessed. It was decided, therefore, to combine these separate but interrelated aspects in one paper. The main part of the paper is devoted to the questions of length-weight relationship and condition. A brief review of the fundamental bases for the concepts of length-weight relationship and condition and of some of the methods of analysis of length-weight data precedes an account of the application of the chosen methods to the present material and its results. This is followed by an account of seasonal changes in gonad weights. A brief account is then given of the rather scanty data available on the weight of stomach contents. The seasonal changes in condition are then described and, finally, some of the results are summarized, combined and discussed as a picture of the seasonal cycle in the Windermere perch. In the statistical analysis of the length-weight relationship the data for only one group of fish are given in full (Tables i and 2) as an example of the method of computation used for all the groups. Again, in the section on seasonal changes in gonad weight and condition Figs. 2-7 are based partly on tables of data which are not published. The full tables have been deposited with the Freshwater Biological Association, from whom copies can be obtained.
3,332 citations
01 Jan 1971
TL;DR: A B S T R A C T Heterologous antiserum was prepared in rabbits against highly purified human antihemophilic factor (AHF, factor VIII) as mentioned in this paper.
Abstract: A B S T R A C T Heterologous antiserum was prepared in rabbits against highly purified human antihemophilic factor (AHF, factor VIII). This antiserum blocked the clot-promoting properties of AHF and, when suitably absorbed, formed a single precipitin line against AHF upon immunoelectrophoresis. Material antigenically similar to normal AHF was detected in normal amounts in plasma concentrates in each of 22 patients with classic hemophilia, in a patient with an acquired circulating anticoagulant against AHF, and in a patient with deficiencies both of AHF and proaccelerin (factor V). AHF-like antigen was present in normal human serum. In contrast, material antigenically related to AHF was found in decreased amounts in the concentrates prepared from the plasma of 11 patients with von Willebrand's disease. The experiments described suggest that von Willebrand's disease is a disorder in which a true deficiency of AHF exists. Whether the AHF-like material
555 citations
TL;DR: The hypocholesterolemic effect of polyunsaturated fat was associated with total fecal sterol excretion twice greater than the amount of cholesterol calculated to leave the plasma, which suggested possible loss of cholesterol from the tissues as well.
Abstract: Six normal men were fed formula diets containing either highly saturated fat (cocoa butter, iodine value 32) or polyunsaturated fat (corn oil, iodine value 125). The sterol balance technique was used to compare the changes in serum cholesterol concentration with the excretion of fecal steroids. The method used for the analysis of fecal steroids was chemical, with a final identification and quantification by gas-liquid chromatography. It was confirmed that the chemical method for fecal steroid analysis was accurate and reproducible. The three dietary periods were each 3 wk in length. In sequence, cocoa butter (period I), corn oil, and cocoa butter (period III) were fed at 40% of the total calories. All diets were cholesterol free, contained similar amounts of plant sterols, and were identical in other nutrients. Corn oil had a hypocholesterolemic effect. Mean serum cholesterol concentrations were 222 mg/100 ml (cocoa butter, period I), 177 during corn oil, and 225 after the return to cocoa butter. Individual fecal steroids were determined from stools pooled for 7 days. Both neutral steroids and bile acids were altered significantly by dietary polyunsaturated fat. The change in bile acid excretion was considerably greater than the change in neutral steroids. Corn oil caused a greater fecal excretion of both deoxycholic and lithocholic acids. The total mean excretion (milligrams per day) of fecal steroids was 709 for cocoa butter (period I), 915 for corn oil, and 629 for the second cocoa butter period. The enhanced total fecal steroid excretion by the polyunsaturated fat of corn oil created a negative cholesterol balance vis-a-vis the saturated fat of cocoa butter. The hypocholesterolemic effect of polyunsaturated fat was associated with total fecal sterol excretion twice greater than the amount of cholesterol calculated to leave the plasma. This finding suggested possible loss of cholesterol from the tissues as well.
259 citations
TL;DR: It is concluded that glucocorticoids increase plasma glucagon concentration in the basal state and in response to protein ingestion or aminogenic stimulation occurs in the face of obesity and persists in chronic hypercorticism.
Abstract: Plasma concentrations of glucagon, insulin, glucose, and individual plasma amino acids were measured in normal nonobese and obese subjects before and after 3 days of dexamethasone treatment (2 mg/day) and in patients with Cushing's syndrome. The subjects were studied in the basal postabsorptive state and following the infusion of alanine (0.15 g/kg) or ingestion of a protein meal. In nonobese subjects dexamethasone treatment resulted in a 55% increment in basal glucagon levels and in a 60-100% increase in the maximal glucagon response to alanine infusion or protein ingestion. In obese subjects, basal glucagon rose by 110% following dexamethasone, while the response to alanine increased fourfold. In patients with Cushing's syndrome basal glucagon levels were 100% higher and the glucagon response to alanine infusion was 170% greater than in normal controls.Dexamethasone treatment in normal subjects resulted in a 40% rise in plasma alanine concentration which was directly proportional to the rise in basal glucagon. The remaining 14 amino acids were unchanged. In the patients with Cushing's syndrome alanine levels were 40% higher than in normal controls and were directly proportional to basal glucagon concentrations. No other plasma amino acids were significantly altered in the group with Cushing's syndrome. It is concluded that (a) glucocorticoids increase plasma glucagon concentration in the basal state and in response to protein ingestion or aminogenic stimulation; (b) this effect of glucocorticoids occurs in the face of obesity and persists in chronic hypercorticism; (c) hyperalaninemia is a characteristic of acute and chronic glucocorticoid excess, and may in turn contribute to steroid-induced hyperglucagonemia; and (d) increased alpha cell secretion may be a contributory factor in the gluconeogenic and diabetogenic effects of glucocorticoids.
247 citations
TL;DR: Sodium and soluble organic solutes accumulation in the roots as a result of salt stress appeared to play an important role in the acclimation to salt stress of the maize genotypes studied, suggesting that they could be used as physiological markers during the screening for salt tolerance.
Abstract: Seeds from eight different maize genotypes (BR3123, BR5004, BR5011, BR5026, BR5033, CMS50, D766 and ICI8447) were sown in vermiculite, and after germination they were transplanted into nutrient solution or nutrient solution containing 100 mmolL-1 of NaCl and placed in a greenhouse During the experimental period plant growth (dry matter, shoot to root dry mass ratio, leaf area, relative growth rate, and net assimilation rate), leaf temperature, stomatal conductance, transpiration, predawn water potential, sodium, potassium, soluble amino acids and soluble carbohydrate contents were determined in both control and salt stressed plants of all genotypes studied Salt stress reduced plant growth of all genotypes but the genotypes BR5033 and BR5011 were characterized as the most salt-tolerant and salt-sensitive, respectively Stomatal response of the salt-tolerant genotype was not affected by salinity Among the studied parameters, shoot to root dry mass ratio, leaf sodium content and leaf soluble organic solute content showed no relation with salt tolerance, ie, they could not be considered as good morpho-physiological markers for maize salt tolerance In contrast, sodium and soluble organic solutes accumulation in the roots as a result of salt stress appeared to play an important role in the acclimation to salt stress of the maize genotypes studied, suggesting that they could be used as physiological markers during the screening for salt tolerance
206 citations