methods for chlorophyll a analysis

... situations. Although the data can be used for various analyses throughout the book, the reader is asked here only to describe in detail how the data can be analyzed. The data appear in examples and ... of all the variables are needed; missing data are a problem. In this example, complete data are available on most of the patients. This may not always be the case. Although there are methods of ... younger at baseline. The deceased patients were significantly older (mean 57 years) than the survivors who participated in the follow-up examination (mean 48 years). 42 EXAMPLES OF SURVIVAL DATA ANALYSIS

Ngày tải lên: 14/08/2014, 05:20

... approach to large-scale survival data is the calculation of the relative survival rate or annual survival ratio. The relative survival rate evaluates the survival experience of patients in terms ... is called standardization and the rate obtained after standardization is called the standardized rate. The most frequently used methods for standardization are the direct method and the indirect ... Assume that survival time t (year) from each of 2418 males with angina pectoris in Example 4.4 has the same format as the data file ‘‘C:!D4d2.DAT’’ defined in Example 4.2 and is saved in

Ngày tải lên: 14/08/2014, 05:20

... increases to a peak at t : ( 9 1)? ?A/ ? ?A, and then declines, which is similar to the lognormal hazard. When  : 1, the hazard starts at ? ?A and then declines monotonically. When :1, the hazard ... that failure or death takes place in n stages or as soon as n subfailures have happened. At the end of the first stage, after time T  , the first subfailure occurs; after that the second stage ... theory and life processes. A natural generalization of the Erlangian distribution is to replace the parameter n restricted to the integers 1, 2, . . . by a parameter  taking any real positive value.

Ngày tải lên: 14/08/2014, 05:20

... lognormal or gamma distribution. The advantages of graphical methods can be summarized as follows: 1. They are fast and simple to use, in contrast with numerical methods, which may be computationally ... tedious and require considerable analyti- cal sophistication. The additional accuracy of numerical methods is usually not great enough in practice to warrant the effort involved. 2. Probability and ... an adequate fit to the data. 4. Peculiar appearance of a plot or points in a plot can provide insight into the data when the reasons for the peculiarities are determined. 5. A graph provides a

Ngày tải lên: 14/08/2014, 05:20

... medical practice Before a physician can make a prognosis and decide on the treatment, a medical history as well as pathologic, clinical, and laboratory data are often needed Therefore, many medical ... quantitatively measured variables (e.g., age), the mean of the values available can be used for a missing value This principle can also be applied to nominal data It does not mean that the mean ... before a multivariate analysis is attempted is to examine the relationship between each individual factor and the dependent variable (e.g., survival time) From the univariate analysis, factors that

Ngày tải lên: 14/08/2014, 05:20

... risk for each variable was calculated by considering favorable or unfavorable values of that variable, assuming that other variables were at their average value. Note that the risk of relapse ... labora- tory data are collected from an interview and physical examination of 200 participants in a study of cardiovascular disease (CVD). These participants, aged 50—79 years and free of CVD at ... years from baseline examination to the first time that a participant was diagnosed as having CVD or confirmed as a CVD death. CVD includes coronary heart disease (CHD) and stroke. The covariates

Ngày tải lên: 14/08/2014, 05:21

... are named TRT, N, and S for the six patients, and coefficients common to all strata can be estimated. Data sets that have been so rearranged are ready for SAS and other software. To use SAS and ... 575... the data are arranged in a certain format The following example illustrates the terms in (13.4.6) and the data format required by SAS Example 13.7 We use again the data in Table 13.6 ... TR—TL. Replacing TR and TL in Tables 13.8 and 13.9 by GT, the data are ready for SAS and other software. Table 13.11 is the corresponding table for the same six patients in Table 13.9 using gap times.

Ngày tải lên: 14/08/2014, 05:21

... that is, an exponentiated coefficient for a continuous covariate is the odds ratio of a 1-unit increase in the covariate assuming that other covariates are the same. Example 14.11 We use the data ... only the data from the normal and CHD participants are used. Similarly, exp(b  ) obtained from the second model can be interpreted as an estimate of the ratio of the odds of a male having STROKE ... clarified. Let us consider modeling the relationship between gender and cardiovascular disease status, NORMAL, STROKE, and CHD (coronary heart disease). Let the outcome variable Y be defined as

Ngày tải lên: 14/08/2014, 05:21

... (1993) Statistical. .. 131—140 Aitkin, M., Laird, N., and Francis, B (1983) A Reanalysis of the Stanford Heart Transplant Data (with discussion) Journal of the American Statistical Association, ... (1952) An Analysis of Some Failure Data Journal of the American Statistical Association, 47, 113—150 Davis, H T., and Feldstein, M L (1979) The Generalized Pareto Law as a Model for Progressively ... (2001) Bayesian Survival Analysis Springer-Verlag, New York Ingram,... Models for Ordinal Data: A Review of Methods and Application International Journal of Epidemiology, 26, 1323—1333 Andersen,

Ngày tải lên: 14/08/2014, 05:21

... program uses the false-discovery rate [33,34] Microarray datasets Nilsson et al R74.11 Additional data files Additional data are available online with this paper Additional data file is a figure representing ... (a) Spearman and (b) Jaccard similarities (Additional data file 3) Proximate methods can be expected to yield similar category rankings (Spearman case) and sets of significant categories (Jaccard ... comparisons (Additional data file 4) based on seven publicly available microarray datasets (see Materials and methods) While a detailed description of the vast amount of resulting data is beyond

Ngày tải lên: 14/08/2014, 07:21

... situations. Although the data can be used for various analyses throughout the book, the reader is asked here only to describe in detail how the data can be analyzed. The data appear in examples and ... of all the variables are needed; missing data are a problem. In this example, complete data are available on most of the patients. This may not always be the case. Although there are methods of ... younger at baseline. The deceased patients were significantly older (mean 57 years) than the survivors who participated in the follow-up examination (mean 48 years). 42 EXAMPLES OF SURVIVAL DATA ANALYSIS

Ngày tải lên: 14/08/2014, 09:22

... is called standardization and the rate obtained after standardization is called the standardized rate. The most frequently used methods for standardization are the direct method and the indirect ... Total 1,000,000 9.37 17.84 (R  )(R  ) 100 Table 4.11 Standardized Death Rates by Indirect Method for Oklahoma and Arizona, 1960 Oklahoma Arizona Standard Population (U.S. Population, ... noncancer deaths and if we find that five-year survival rate of the general population is 0.9, the corrected survival rate is 0.5/0.9, or 0.56. 4.4 STANDARDIZED RATES AND RATIOS Rates and ratios are often

Ngày tải lên: 14/08/2014, 09:22

... exponential distribution. Both describe survival patterns that have a constant initial hazard rate. The hazard rate varies as a linear function of time or age in the linear-exponential model and as an ... increases to a peak at t :( 9 1)? ?A/ ? ?A, and then declines, which is similar to the lognormal hazard. When : 1, the hazard starts at ? ?A and then declines monotonically. When :1, the hazard ... We then obtain the gamma distribution. The gamma distribution is characterized by two parameters,  and . When 0 ::1, there is negative aging and the hazard rate decreases monotonically from

Ngày tải lên: 14/08/2014, 09:22

... that length of time and then failed. It is an observed conditional failure probability for an uncensored observation. Step 4. For each uncensored observation, calculate the cumulative hazard value. ... the data in Example 8.2. corresponding to log+1/[1 9F(t)], : 1 is an estimate of the mean 1/ and its reciprocal is an estimate of the hazard rate . Example 8.2 Suppose that 21 patients with acute ... the hazard values of the uncensored observation and of all preceding uncensored observations. For tied uncensored observations, the cumulative hazard is evaluated only at the smallest K among

Ngày tải lên: 14/08/2014, 09:22

... file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been ... initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to APPENDIX A TO PART 136 METHODS FOR ORGANIC CHEMICAL ... precision and accuracy, respectively, found in Table 5. If s and for all parameters of interest meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can...

Ngày tải lên: 05/03/2014, 21:20

... analytical system and glassware are under control. Each time a set of samples is extracted or reagents are changed a reagent water blank must be processed as a safeguard against laboratory contamination. 8.1.4 ... recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4. 8.4 If any parameter fails ... calibration standard according to Section 11 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors (RF) for each compound...

Ngày tải lên: 05/03/2014, 21:20

... processed as a safeguard against laboratory contamination. 8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. ... recovery, that parameter has failed the acceptance criteria. A check standard containing each parameter that failed the criteria must be analyzed as described in Section 8.4. 8.4 If any parameter fails ... this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records...

Ngày tải lên: 14/03/2014, 20:20

... processed as a safeguard against laboratory contamination. 8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples to monitor and evaluate laboratory data quality. ... file of material data handling sheets should also be made available to all personnel involved in the chemical analysis. Additional references to laboratory safety are available and have been ... of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records to document the quality of data that is generated....

Ngày tải lên: 14/03/2014, 20:20

... extracted or reagents are changed, a reagent water blank must be processed as a safeguard against laboratory contamination. 8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum ... µL, analyze each calibration standard according to Section 12 and tabulate peak height or area responses against concentration for each compound and internal standard. Calculate response factors ... this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records...

Ngày tải lên: 22/03/2014, 14:20

... this program consist of an initial demonstration of laboratory capability and an ongoing analysis of spiked samples to evaluate and document data quality. The laboratory must maintain records ... acceptance criteria for precision and accuracy, respectively, found in Table 2. If s and meet the acceptance criteria, the system performance is acceptable and analysis of actual samples can begin. ... processed as a safeguard against laboratory contamination. 8.1.4 The laboratory must, on an ongoing basis, spike and analyze a minimum of 10% of all samples with native 2,3,7,8-TCDD to monitor and evaluate...

Ngày tải lên: 28/03/2014, 20:20