scholarly journals The adjustment of biological assay results for variation in concomitant observations

1947 ◽  
Vol 45 (4) ◽  
pp. 397-406 ◽  
Author(s):  
D. J. Finney
Keyword(s):  
Statistical Tests ◽  
Covariance Analysis ◽  
The Body ◽  
Biological Assay ◽  
Gland Weight ◽  
Body Weights ◽  
The Mean ◽  
Measured Response ◽  
Considerable Doubt ◽  
Arbitrary Assumption

When individual responses in a biological assay show considerable variation associated with the values of a concomitant variate, covariance analysis may be used in order to adjust the mean responses and to improve the precision of the assay. Usually this is preferable to the choice of an adjustment which involves an arbitrary assumption about the effect of variations in the concomitant variate on the measured response. Published accounts of the process are open to certain theoretical objections, though they may be sufficiently exact for most practical purposes.The present paper describes a method of calculating the relative potency, and its precision, which may be a little more laborious, but which is in full accord with standard statistical practice. The computations are illustrated on data from a prolactin assay by the pigeon crop-gland technique, in which the final crop-gland weight showed a positive correlation with the body weight at the start of the assay. The results are compared with those obtained either from the unadjusted crop-gland weights or from these weights expressed as proportions of body weights. The covariance method leads to a more precise estimate of the potency of the test preparation than do either of the others; there is evidence, however, that the increase in precision will not necessarily be large unless the correlation between the response and the concomitant variate is very close.In a final section, the full statistical tests of assay validity in the covariance analysis are described; these are lengthy, and fortunately are required only when the validity is in considerable doubt.The methods of adjustment have been described in this paper with respect to an assay depending upon parallel regression lines of responses on the logarithms of doses. They may be adapted for use with ‘slope-ratio’ assays (Bliss, 1946; Finney, 1945; 1948; Wood & Finney, 1946), in which the regression of response on dose itself is linear. So far the need for adjusting for concomitant variation in these assays seems not to have arisen, and discussion of computational details may be postponed until the need is felt.

scholarly journals PREVALENCE OF HEPATIC STEATOSIS AMONG CHILDREN AND ADOLESCENTS WITH CYSTIC FIBROSIS AND ITS ASSOCIATION WITH NUTRITIONAL STATUS

2019 ◽  
Vol 37 (4) ◽  
pp. 435-441
Author(s):  
Amanda Oliva Gobato ◽  
Ana Carolina Junqueira Vasques ◽  
Antonio Fernando Ribeiro ◽  
Roberto Massao Yamada ◽  
Gabriel Hessel
Keyword(s):  
Cystic Fibrosis ◽  
Nutritional Status ◽  
Children And Adolescents ◽  
Hepatic Steatosis ◽  
Statistical Tests ◽  
The Body ◽  
Significant Difference ◽  
Group A ◽  
The Mean ◽  
Group B

ABSTRACT Objective: To determine the prevalence of hepatic steatosis (HS) in children and adolescents with cystic fibrosis (CF) and associate it with nutritional status. Methods: Cross-sectional study with children and adolescents with CF diagnosis. Weight and height were used to calculate the body mass index (BMI) and subsequent classification of the nutritional status. The midarm circumference (MAC), triceps skinfold thickness (TSF) and midarm muscle circumference (MAMC) were used to evaluate body composition. Abdominal ultrasonography was performed for diagnosis of HS. The statistical tests used were Student’s t test, Mann-Whitney test and chi-square test with significance level of 5%. Results: 50 patients with CF were evaluated, 18 (36%) were diagnosed with HS (Group A) and 32 (64%) without HS (Group B). The mean age of Group A was 13,2±4,9 years old and Group B 11,7±4,9; for BMI, the value for Group A was 18,0±4,1 and Group B was 15,7±3,8; the TSF of Group A was 8,4±3,5 mm and Group B was 7,0±2,5 mm. For these variables, there was no significant difference between the groups. The mean of MAC and MAMC differed significantly between the groups, being higher in the HS group, with p values of 0,047 and 0,043. Conclusions: The frequency of HS in patients with CF is high and it is not related to malnutrition, according to the parameters of BMI, TSF and MAMC. The values of MAC and MAMC indicated a greater reserve of muscle mass in patients with HS.

Maintenance rations for Merino sheep. IV. The performance of adult Merino ewes fed daily and weekly at three levels of energy intake

1957 ◽  
Vol 8 (1) ◽  
pp. 75 ◽  
Author(s):  
PK Briggs ◽  
MC Franklin ◽  
GL McClymont
Keyword(s):  
Body Weight ◽  
Sodium Chloride ◽  
Energy Intake ◽  
Survival Rates ◽  
Experimental Period ◽  
The Body ◽  
Merino Sheep ◽  
Wool Production ◽  
Body Weights ◽  
The Mean

Dry adult Merino ewes were fed at daily or weekly intervals on oat grain at levels which provided 4.0, 3.0, or 2.0 lb starch equivalent (S.E.) per sheep per week. The experimental periods were 223, 223, and 181 days respectively. Differences between the mean body weights of the ewes a t the three levels of feeding were highly significant (P < 0.001). Body weight varied only slightly and no losses occurred in ewes fed weekly at the rate of 4.0 lb S.E. per head. Ewes fed daily a t this level had a significantly greater mean body weight (P < 0.001) a t the conclusion of the 223-day experimental period. The addition of a sodium chloride supplement did not improve the body weight or wool production of ewes fed weekly a t the level of 4.0 lb S.E. The mean body weight of ewes fed at the levels of 3.0 or 2.0 lb S.E. per head declined over the first 12 and 18 respectively and thereafter remained relatively constant. There were no significant differences at these levels of feeding between groups fed daily and weekly in respect of body weight, wool production, or survival rates. Ewes fed a t the level of 4.0 lb S.E. grew significantly more wool than those given 3.0 lb S.E. (P < 0.001). Losses were negligible in all groups except those fed a t the level of 2.0 lb S.E. In these groups there were few deaths in the first 16 weeks, but in the subsequent 10 weeks losses totalled 17.1 per cent. Ewes fed a t the level of 2.0 lb S.E. consumed their rations at a significantly slower rate (P < 0.01) than did those fed a t the level of 4.0 lb S.E.

AUTOMATIC WEIGHING OF POULTRY REARED ON A LITTER FLOOR

1989 ◽  
Vol 69 (4) ◽  
pp. 1075-1081 ◽  
Author(s):  
IRENE DOYLE ◽  
STEVE LEESON
Keyword(s):  
Key Words ◽  
Broiler Chickens ◽  
The Body ◽  
Body Weights ◽  
Plate Size ◽  
The Mean

Four trials were conducted to test the accuracy of an automatic weighing system with broiler chickens and turkeys. Body weights were recorded manually and automatically and compared statistically. The body weights obtained automatically were similar to body weights recorded manually (P > 0.05) with broilers weighing up to 2 kg and turkeys up to 2.5 kg. A larger plate size would be required to weigh heavier birds. The number of weights recorded per day varied according to age of bird. The sex of the bird, however, did not influence the number of weights recorded (P > 0.05). The automatic weighing system was shown to record a daily mean comparable to the mean obtained manually. Key words: Poultry, weighing, automation

Comparative nitrogen digestibility in Brahman, Brahman × Shorthorn, Africander × Hereford, and Hereford Steers

1962 ◽  
Vol 58 (3) ◽  
pp. 333-342 ◽  
Author(s):  
G. C. Ashton
Keyword(s):  
Body Weight ◽  
Nitrogen Metabolism ◽  
The Body ◽  
Dry Matter Digestibility ◽  
Natural Pasture ◽  
Breed Difference ◽  
Body Weights ◽  
Faecal Nitrogen ◽  
The Mean ◽  
The Relationship

1. Eight nitrogen metabolism experiments, each with sixteen steers representing grade Brahman, Brahman x Shorthorn, Africander x Hereford and Herefords, were carried out. The steers were fed according to body weight to the power 0·73, on rations consisting of natural pasture hay alone or in combination with lucerne hay.2. These experiments showed that the steers with zebu blood were significantly superior to the Herefords with regard to dry-matter digestibility and apparent nitrogen digestibility. The breed difference disappeared when nitrogen digestibility was calculated from the relationship feed nitrogen minus undigested faecal residue nitrogen, divided by feed nitrogen.3. Two further nitrogen metabolism experiments with six Africander x Hereford and four Hereford steers fed natural pasture hay plus lucerne hay, and one experiment with two Brahman x Shorthorn, two Africander x Hereford and two Hereford steers fed chaffed wheat straw were carried out. The steers were fed an equal amount of ration, irrespective of body weight.4. In these three experiments faecal nitrogen was fractionated into undigested residue nitrogen, non-dialysable centrifugable nitrogen, non-dialysable non-centrifugable nitrogen, and dialysable nitrogen. The breed groups differed significantly in the amount of dialysable faecal nitrogen excreted but not in any other component.5. The amount of dialysable faecal nitrogen excreted on equal intake was very significantly negatively correlated with body weight (r = −0·807, P < 0·01).6. It was found that in two experiments the mean difference between Africander x Herefords and Hereford steers, mean body weights 863 and 686 lb., respectively, was 1·81 ± 0·51 g. nitrogen per day. It was calculated that this would represent about 70 ± 20% of the body-weight difference between the breeds if the lost nitrogen was fully utilizable. This agreed well with the estimate of 65% derived from the square of the correlation coefficient.

Effects of Chronic Exposure to Sublethal pH on Growth, Egg Production, and Ovulation in Brook Trout, Salvelinus fontinalis

1986 ◽  
Vol 43 (2) ◽  
pp. 275-280 ◽  
Author(s):  
W. H. Tam ◽  
P. D. Payson
Keyword(s):  
Brook Trout ◽  
Egg Production ◽  
Salvelinus Fontinalis ◽  
Experimental Period ◽  
The Body ◽  
Oocyte Development ◽  
Control Fish ◽  
Ph Values ◽  
Body Weights ◽  
The Mean

Hatchery-reared brook trout (Salvelinus fontinalis) were maintained in the laboratory at mean pH values of 7.34, 5.56, 5.16, and 4.48 from early February to early December. At pH 4.48, the mean growth rates of males were uniformly lowered during the entire experimental period. Among females, growth was inhibited during the first 5 mo, but their rate of weight gain recovered during the period of rapid oocyte development. At the end of the experiment, the body weights of both male and female fish in pH 5.16 and 4.48 were only 70.70–77.34% of the control fish at pH 7.34. Growth was not affected by exposure to pH 5.56. Rapid oocyte development occurred simultaneously over all pH groups in June, suggesting that the initiation of gametogenesis was not affected over the range of pH tested, the number of eggs produced was significantly correlated to body weight; consequently the number of eggs produced by the smaller pH 5.16–4.48 females was reduced. Ovulation was also significantly delayed in the acidic groups.

scholarly journals Relationship between birth weight and body growth characteristics of lambs

2014 ◽  
Vol 30 (2) ◽  
pp. 193-201
Author(s):  
M.P. Petrovic ◽  
V.C. Petrovic ◽  
Z. Ilic ◽  
D. Ruzic-Muslic ◽  
M.M. Petrovic ◽  
...  
Keyword(s):  
Body Weight ◽  
Correlation Coefficients ◽  
The Body ◽  
Group Differences ◽  
Maximum Weight ◽  
The Third ◽  
Body Weights ◽  
The Mean ◽  
Average Body ◽  
Average Body Weight

Research was carried out in population of R2 generation Pirot pramenka x Pirot improved sheep during period of three years. Lambs were divided into three groups: I from 2.5 kg to 3.5 kg; II from 3.6 kg to 4.5 kg; III from 4.6 kg to 5.5 kg. Weight of lambs was controlled at birth, with 30, 60 and 90 days of age. Average body weight at birth of the tested lambs was 3.35 kg in the first group, 4.30 kg in the second group and 5.06 kg in the third group. At 30 days of age, the body weight of the lambs was 10.19 kg in the first group, 11.39 kg in the second and 12.49 kg in the third group. All these differences in body weight of lambs at birth were statistically highly significant (P_ 0.01). With 60 days of age, average body weight was 16.48 kg in the first group, 19.01 kg in the second and 20.49 kg in the third group. Differences between groups of lambs at this age were statistically very significant (P_0.01).On the end of experiment at 90 days of lambs age, we have found the following values of the body weight of lambs: 26.35 kg in the first group, when the second 30.49 kg and 28.93 kg in the third group. Differences between groups of lambs at this age were statistically very significant (P_0.01). At the age of 90 days maximum weight of the body was in the second group of lambs, or a group which body weight at birth occupied the mean of the population. Correlations between body weights of lambs vary from weak to midsized values. The highest values of correlation coefficients were found between body weight at birth and weight of lambs at 30 days of age.

scholarly journals Hubungan Berat Induk dan Berat Sapi Anak Sapi

2016 ◽  
Vol 7 (1) ◽  
pp. 18-21
Author(s):  
Sulaiman Ibrahim
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Artificial Insemination ◽  
The Body ◽  
Frozen Semen ◽  
Body Weights ◽  
The Mean ◽  
Mating Method

ABSTRACT. A survey conducted to study a relationship between a dam body weight and a calf birth weight of cattle. There were six dams of Brahman Cross (B.C), six females calves of B.C dam, eleven local cattle dams and her eleven females calves, and another seven dams of local cattle and her seven male calves. The mean birth weight were local cattle and her seven male calves. The mean birth weight were 20.67 ±13.47 Kg for the female calf of B.C dam, and 19.27 ± 4.41 Kg for thr female calf of local cattle dam, and 18 ± 2.33 Kg for the male calf of local cattle dam. The mating method used was an artificial insemination and Brahman Cross frozen semen. The birth weight between the two groups of these female calves were not significantly different, and berween the two groubs of these female calves and the male calves were not significantly different. The body weights of B.C dams were not significantly correlated with their female calves ( r= + 0.7166, P0.05), and the local dam body weights were not significantly correlated with their female calves (r=+0.7450, P0.05), and with their male calves (r=+ 0.1948, P0.05). The equation of the regression lines were Y = 5.38 + 0.07 X for female calves and Y = 16.21 + 0.01 X for male calves. X dam body wight, and Y = calf birth weight.

scholarly journals Comparative morphometry of the brainstem of the male and female Helmeted Guinea Fowl (Numida meleagris)

2018 ◽  
Vol 51 (3) ◽  
pp. 121-124
Author(s):  
Mohammed Adam ◽  
Barth Izuchukwu Onyeanusi ◽  
Joseph Olusegun Hambolu ◽  
Suleiman Folorunsho Ambali ◽  
Chikera Samuel Ibe
Keyword(s):  
Medulla Oblongata ◽  
Guinea Fowl ◽  
The Body ◽  
Base Line ◽  
Male And Female ◽  
Numida Meleagris ◽  
Body Weights ◽  
The Mean ◽  
The Difference ◽  
The Brain

Abstract The aim of this study was to obtain base-line morphometric data on the whole brain and brainstem in the adult male and female helmeted guinea fowl (Numida meleagris), and compare the result in the two sexes. Brain samples of seventy adult helmeted guinea fowls, comprising 35 males and 35 females, intended for slaughter, were extracted for the study. The body weights for both male and female helmeted guinea fowls were 1247 ± 5.51 g and 1230 ± 4.85 g, respectively. The mean brain weights were 3.39 ± 0.02 g and 3.47 ± 0.18 g for male and female, respectively, and the difference in the values was not significant (P > 0.05). The lengths of the brain and medulla oblongata, as well as the lengths of the midbrain and mesencephalic tectum, did not differ between the two sexes. Neither the mean weights nor lengths of the pons differed between the two sexes. In conclusion, the results of this study showed that there was no sex dimorphism observed in the morphometry of the midbrain, medulla oblongata and pons in the helmeted guinea fowl.

scholarly journals Comparative morphometry of the brainstem of the male and female Helmeted Guinea Fowl (Numida meleagris)

2018 ◽  
Vol 51 (3) ◽  
pp. 121-124
Author(s):  
Mohammed Adam ◽  
Barth Izuchukwu Onyeanusi ◽  
Joseph Olusegun Hambolu ◽  
Suleiman Folorunsho Ambali ◽  
Chikera Samuel Ibe
Keyword(s):  
Medulla Oblongata ◽  
Guinea Fowl ◽  
The Body ◽  
Base Line ◽  
Male And Female ◽  
Numida Meleagris ◽  
Body Weights ◽  
The Mean ◽  
The Difference ◽  
The Brain

Abstract The aim of this study was to obtain base-line morphometric data on the whole brain and brainstem in the adult male and female helmeted guinea fowl (Numida meleagris), and compare the result in the two sexes. Brain samples of seventy adult helmeted guinea fowls, comprising 35 males and 35 females, intended for slaughter, were extracted for the study. The body weights for both male and female helmeted guinea fowls were 1247 ± 5.51 g and 1230 ± 4.85 g, respectively. The mean brain weights were 3.39 ± 0.02 g and 3.47 ± 0.18 g for male and female, respectively, and the difference in the values was not significant (P > 0.05). The lengths of the brain and medulla oblongata, as well as the lengths of the midbrain and mesencephalic tectum, did not differ between the two sexes. Neither the mean weights nor lengths of the pons differed between the two sexes. In conclusion, the results of this study showed that there was no sex dimorphism observed in the morphometry of the midbrain, medulla oblongata and pons in the helmeted guinea fowl.

L-Ascorbic Acid Addition to Chitosan Reduces Body Weight in Overweight Women

2014 ◽  
Vol 84 (1-2) ◽  
pp. 5-11 ◽  
Author(s):  
Eun Y. Jung ◽  
Sung C. Jun ◽  
Un J. Chang ◽  
Hyung J. Suh
Keyword(s):  
Ascorbic Acid ◽  
Body Weight ◽  
Fat Body ◽  
Body Weight Gain ◽  
Skinfold Thickness ◽  
The Body ◽  
Control Group ◽  
Percentage Body Fat ◽  
Overweight Women ◽  
Body Weights

Previously, we have found that the addition of L-ascorbic acid to chitosan enhanced the reduction in body weight gain in guinea pigs fed a high-fat diet. We hypothesized that the addition of L-ascorbic acid to chitosan would accelerate the reduction of body weight in humans, similar to the animal model. Overweight subjects administered chitosan with or without L-ascorbic acid for 8 weeks, were assigned to three groups: Control group (N = 26, placebo, vehicle only), Chito group (N = 27, 3 g/day chitosan), and Chito-vita group (N = 27, 3 g/day chitosan plus 2 g/day L-ascorbic acid). The body weights and body mass index (BMI) of the Chito and Chito-vita groups decreased significantly (p < 0.05) compared to the Control group. The BMI of the Chito-vita group decreased significantly compared to the Chito group (Chito: -1.0 kg/m2 vs. Chito-vita: -1.6 kg/m2, p < 0.05). The results showed that the chitosan enhanced reduction of body weight and BMI was accentuated by the addition of L-ascorbic acid. The fat mass, percentage body fat, body circumference, and skinfold thickness in the Chito and Chito-vita groups decreased more than the Control group; however, these parameters were not significantly different between the three groups. Chitosan combined with L-ascorbic acid may be useful for controlling body weight.

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