Milk production from a naturalized pasture at Wollongbar and its relation to rainfall

1971 ◽  
Vol 11 (53) ◽  
pp. 604
Author(s):  
H Jeffery ◽  
RL Colman ◽  
FG Swain

The 4 per cent fat corrected milk (FCM) production obtained from cows grazing a 9.7 ha farmlet of naturalized pasture at Wollongbar was measured over the ten-year period to 1968. FCM per cow varied between 1538 kg and 2765 kg and per hectare between 1678 kg and 2847 kg. The factors most likely to have affected production appeared to be climatic effects. It is suggested that soil fertility was unlikely to have affected production markedly and the relation between FCM production per hectare, and several rainfall parameters were established. The most important factor affecting production appeared to be rainfall in early to mid-lactation. Knowledge of rainfall during this period accounted for 93 per cent of the total variation in FCM per hectare between years. The residual standard deviation of the regression was 5 per cent of the mean production per hectare.

1991 ◽  
Vol 52 (2) ◽  
pp. 263-269 ◽  
Author(s):  
G. A. J. Fursey ◽  
C. A. Miles ◽  
S. J. Page ◽  
A. V. Fisher

ABSTRACTMeasurements were made of the speed of ultrasound transmission through sites in the hind limbs of 125 pedigree Hereford bulls. Twenty-five of these were measured twice at weekly intervals on three occasions prior to slaughter to assess the short-term repeatability of the measurement and the magnitude of long-term changes. Analyses of variance of the means of the measurements at two sites showed that the residual standard deviation (within animal and occasion), was 0·01 (μs/cm. There was a decrease of 0·01 (μs/cm in the group mean over the 2-week period and a significant time × animal interaction. This showed that lipid concentration at the measurement sites decreased as the bulls adjusted to their new surroundings following delivery to the Institute's farm. When a separate group of 64 bulls was measured at the farm at which they were being reared an increase in the group mean of 0·006 iμs/cm was recorded over a 30·day period, indicating an increase in lipid concentration. The residual standard deviation for that group was 0·007 μs/cm, similar to that recorded above.The mean of the reciprocal speeds at the two sites, when used in a multiple regression with live mass, yielded a residual standard deviation in predicted proportion of lean in the side of 20·0 g/kg and in total fat proportion of 22·1 g/kg. These corresponded to population standard deviations, adjusted for live mass, of 29·7 and 34·1 g/kg respectively. It was concluded that the measurement of ultrasound speed in the hind limbs of Hereford bulls could be used to predict lean proportion in the carcass. The method does not require subjective interpretation and responds equally to subcutaneous and interand intra-muscular fat.


1986 ◽  
Vol 42 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Susan Brotherstone ◽  
W. G. Hill

ABSTRACTEstimates were obtained of the variability among herds of dairy cattle of the standard deviation (s.d.) and coefficient of variation (CV) of milk, fat and protein yield. For fat yield, for example, the mean s.d. within herds for heifers was about 30 kg, the s.d. among herds was 5·2 kg and the mean and s.d. of CV were 0·15 and 0·026, respectively. Correlations of both s.d. and CV were high between both heifers and cows in the same herd and year and between heifers or cows in the same herd in successive years, showing that variability was consistent over time and over age groups.Ways of correcting for the heterogeneity of variance for use in cow index calculations are suggested; because CVs are heterogeneous, simple log transformation is not sufficient.


1969 ◽  
Vol 14 (9) ◽  
pp. 470-471
Author(s):  
M. DAVID MERRILL
Keyword(s):  

1972 ◽  
Vol 28 (03) ◽  
pp. 447-456 ◽  
Author(s):  
E. A Murphy ◽  
M. E Francis ◽  
J. F Mustard

SummaryThe characteristics of experimental error in measurement of platelet radioactivity have been explored by blind replicate determinations on specimens taken on several days on each of three Walker hounds.Analysis suggests that it is not unreasonable to suppose that error for each sample is normally distributed ; and while there is evidence that the variance is heterogeneous, no systematic relationship has been discovered between the mean and the standard deviation of the determinations on individual samples. Thus, since it would be impracticable for investigators to do replicate determinations as a routine, no improvement over simple unweighted least squares estimation on untransformed data suggests itself.


2017 ◽  
Vol 4 (2) ◽  
pp. 87-91
Author(s):  
Ekamaida Ekamaida

The soil fertility aspect is characterized by the good biological properties of the soil. One important element of the soil biological properties is the bacterial population present in it. This research was conducted in the laboratory of Microbiology University of Malikussaleh in the May until June 2016. This study aims to determine the number of bacterial populations in soil organic and inorganic so that can be used as an indicator to know the level of soil fertility. Data analysis was done by T-Test that is by comparing the mean of observation parameter to each soil sample. The sampling method used is a composite method, which combines 9 of soil samples taken from 9 sample points on the same plot diagonally both on organic soil and inorganic soil. The results showed the highest bacterial population was found in total organic soil cfu 180500000 and total inorganic soil cfu 62.500.000


2020 ◽  
Vol 1 (2) ◽  
pp. 56-66
Author(s):  
Irma Linda

Background: Early marriages are at high risk of marital failure, poor family quality, young pregnancies at risk of maternal death, and the risk of being mentally ill to foster marriage and be responsible parents. Objective: To determine the effect of reproductive health education on peer groups (peers) on the knowledge and perceptions of adolescents about marriage age maturity. Method: This research uses the Quasi experimental method with One group pre and post test design, conducted from May to September 2018. The statistical analysis used in this study is a paired T test with a confidence level of 95% (α = 0, 05). Results: There is an average difference in the mean value of adolescent knowledge between the first and second measurements is 0.50 with a standard deviation of 1.922. The mean difference in mean scores of adolescent perceptions between the first and second measurements was 4.42 with a standard deviation of 9.611. Conclusion: There is a significant difference between adolescent knowledge on the pretest and posttest measurements with a value of P = 0.002, and there is a significant difference between adolescent perceptions on the pretest and posttest measurements with a value of p = 0.001. Increasing the number of facilities and facilities related to reproductive health education by peer groups (peers) in adolescents is carried out on an ongoing basis at school, in collaboration with local health workers as prevention of risky pregnancy.


1988 ◽  
Vol 60 (1) ◽  
pp. 1-29 ◽  
Author(s):  
E. D. Young ◽  
J. M. Robert ◽  
W. P. Shofner

1. The responses of neurons in the ventral cochlear nucleus (VCN) of decerebrate cats are described with regard to their regularity of discharge and latency. Regularity is measured by estimating the mean and standard deviation of interspike intervals as a function of time during responses to short tone bursts (25 ms). This method extends the usual interspike-interval analysis based on interval histograms by allowing the study of temporal changes in regularity during transient responses. The coefficient of variation (CV), equal to the ratio of standard deviation to mean interspike interval, is used as a measure of irregularity. Latency is measured as the mean and standard deviation of the latency of the first spike in response to short tone bursts, with 1.6-ms rise times. 2. The regularity and latency properties of the usual PST histogram response types are shown. Five major PST response type classes are used: chopper, primary-like, onset, onset-C, and unusual. The presence of a prepotential in a unit's action potentials is also noted; a prepotential implies that the unit is recorded from a bushy cell. 3. Units with chopper PST histograms give the most regular discharge. Three varieties of choppers are found. Chop-S units (regular choppers) have CVs less than 0.35 that are approximately constant during the response; chop-S units show no adaptation of instantaneous rate, as measured by the inverse of the mean interspike interval. Chop-T units have CVs greater than 0.35, show an increase in irregularity during the response and show substantial rate adaptation. Chop-U units have CVs greater than 0.35, show a decrease in irregularity during the response, and show a variety of rate adaptation behaviors, including negative adaptation (an increase in rate during a short-tone response). Irregular choppers (chop-T and chop-U units) rarely have CVs greater than 0.5. Choppers have the longest latencies of VCN units; all three groups have mean latencies at least 1 ms longer than the shortest auditory nerve (AN) fiber mean latencies. 4. Chopper units are recorded from stellate cells in VCN (35, 42). Our results for chopper units suggest a model for stellate cells in which a regularly firing action potential generator is driven by the summation of the AN inputs to the cell, where the summation is low-pass filtered by the membrane capacitance of the cell.(ABSTRACT TRUNCATED AT 400 WORDS)


Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2421
Author(s):  
Roberta Fusco ◽  
Vincenza Granata ◽  
Mauro Mattace Raso ◽  
Paolo Vallone ◽  
Alessandro Pasquale De Rosa ◽  
...  

Purpose. To combine blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), dynamic contrast enhanced MRI (DCE-MRI), and diffusion weighted MRI (DW-MRI) in differentiation of benign and malignant breast lesions. Methods. Thirty-seven breast lesions (11 benign and 21 malignant lesions) pathologically proven were included in this retrospective preliminary study. Pharmaco-kinetic parameters including Ktrans, kep, ve, and vp were extracted by DCE-MRI; BOLD parameters were estimated by basal signal S0 and the relaxation rate R2*; and diffusion and perfusion parameters were derived by DW-MRI (pseudo-diffusion coefficient (Dp), perfusion fraction (fp), and tissue diffusivity (Dt)). The correlation coefficient, Wilcoxon-Mann-Whitney U-test, and receiver operating characteristic (ROC) analysis were calculated and area under the ROC curve (AUC) was obtained. Moreover, pattern recognition approaches (linear discrimination analysis and decision tree) with balancing technique and leave one out cross validation approach were considered. Results. R2* and D had a significant negative correlation (−0.57). The mean value, standard deviation, Skewness and Kurtosis values of R2* did not show a statistical significance between benign and malignant lesions (p > 0.05) confirmed by the ‘poor’ diagnostic value of ROC analysis. For DW-MRI derived parameters, the univariate analysis, standard deviation of D, Skewness and Kurtosis values of D* had a significant result to discriminate benign and malignant lesions and the best result at the univariate analysis in the discrimination of benign and malignant lesions was obtained by the Skewness of D* with an AUC of 82.9% (p-value = 0.02). Significant results for the mean value of Ktrans, mean value, standard deviation value and Skewness of kep, mean value, Skewness and Kurtosis of ve were obtained and the best AUC among DCE-MRI extracted parameters was reached by the mean value of kep and was equal to 80.0%. The best diagnostic performance in the discrimination of benign and malignant lesions was obtained at the multivariate analysis considering the DCE-MRI parameters alone with an AUC = 0.91 when the balancing technique was considered. Conclusions. Our results suggest that the combined use of DCE-MRI, DW-MRI and/or BOLD-MRI does not provide a dramatic improvement compared to the use of DCE-MRI features alone, in the classification of breast lesions. However, an interesting result was the negative correlation between R2* and D.


2021 ◽  
Vol 9 (6) ◽  
pp. 585
Author(s):  
Minghao Wu ◽  
Leen De Vos ◽  
Carlos Emilio Arboleda Chavez ◽  
Vasiliki Stratigaki ◽  
Maximilian Streicher ◽  
...  

The present work introduces an analysis of the measurement and model effects that exist in monopile scour protection experiments with repeated small scale tests. The damage erosion is calculated using the three dimensional global damage number S3D and subarea damage number S3D,i. Results show that the standard deviation of the global damage number σ(S3D)=0.257 and is approximately 20% of the mean S3D, and the standard deviation of the subarea damage number σ(S3D,i)=0.42 which can be up to 33% of the mean S3D. The irreproducible maximum wave height, chaotic flow field and non-repeatable armour layer construction are regarded as the main reasons for the occurrence of strong model effects. The measurement effects are limited to σ(S3D)=0.039 and σ(S3D,i)=0.083, which are minor compared to the model effects.


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