This document discusses standard deviation and related statistical concepts. It defines standard deviation as a measure of variability around the mean and explains how to calculate it from both ungrouped and grouped data. It also defines related terms like variance, standard error of the mean, and confidence limits of the mean. Standard deviation is calculated using the formula that sums the squared deviations from the mean, divided by n-1. Standard error is the standard deviation divided by the square root of the sample size, and confidence limits refer to ranges around the mean within which we can be certain the population mean falls.
Standard error is used in the place of deviation. it shows the variations among sample is correlate to sampling error. list of formula used for standard error for different statistics and applications of tests of significance in biological sciences
A brief description of F Test and ANOVA for Msc Life Science students. I have taken the example slides from youtube where an excellent explanation is available.
Here is the link : https://www.youtube.com/watch?v=-yQb_ZJnFXw
Standard error is used in the place of deviation. it shows the variations among sample is correlate to sampling error. list of formula used for standard error for different statistics and applications of tests of significance in biological sciences
A brief description of F Test and ANOVA for Msc Life Science students. I have taken the example slides from youtube where an excellent explanation is available.
Here is the link : https://www.youtube.com/watch?v=-yQb_ZJnFXw
Today’s overwhelming number of techniques applicable to data analysis makes it extremely difficult to define the most beneficial approach while considering all the significant variables.
The analysis of variance has been studied from several approaches, the most common of which uses a linear model that relates the response to the treatments and blocks. Note that the model is linear in parameters but may be nonlinear across factor levels. Interpretation is easy when data is balanced across factors but much deeper understanding is needed for unbalanced data.
Analysis of variance (ANOVA) is a collection of statistical models and their associated estimation procedures (such as the "variation" among and between groups) used to analyze the differences among means. ANOVA was developed by the statistician Ronald Fisher. ANOVA is based on the law of total variance, where the observed variance in a particular variable is partitioned into components attributable to different sources of variation. In its simplest form, ANOVA provides a statistical test of whether two or more population means are equal, and therefore generalizes the t-test beyond two means. In other words, the ANOVA is used to test the difference between two or more means.Analysis of variance (ANOVA) is an analysis tool used in statistics that splits an observed aggregate variability found inside a data set into two parts: systematic factors and random factors. The systematic factors have a statistical influence on the given data set, while the random factors do not. Analysts use the ANOVA test to determine the influence that independent variables have on the dependent variable in a regression study.
Sir Ronald Fisher pioneered the development of ANOVA for analyzing results of agricultural experiments.1 Today, ANOVA is included in almost every statistical package, which makes it accessible to investigators in all experimental sciences. It is easy to input a data set and run a simple ANOVA, but it is challenging to choose the appropriate ANOVA for different experimental designs, to examine whether data adhere to the modeling assumptions, and to interpret the results correctly. The purpose of this report, together with the next 2 articles in the Statistical Primer for Cardiovascular Research series, is to enhance understanding of ANVOA and to promote its successful use in experimental cardiovascular research. My colleagues and I attempt to accomplish those goals through examples and explanation, while keeping within reason the burden of notation, technical jargon, and mathematical equations.
Statistical tests of significance and Student`s T-TestVasundhraKakkar
Statistical tests of significance is explained along with steps involve in Statistical tests of significance and types of significance test are also mentioned. Student`s T-Test is explained
The ppt cover General Introduction to the topic,
Description of CHI-SQUARE TEST, Contingency table, Degree of Freedom, Determination of Chi – square test, Assumption for validity of chi - square test, Characteristics , Applications, Limitations
Measures of dispersion
Absolute measure, relative measures
Range of Coe. of Range
Mean deviation and coe. of mean deviation
Quartile deviation IQR, coefficient of QD
Standard deviation and coefficient of variation
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdfRavinandan A P
Biostatistics, Unit-I, Measures of Dispersion, Dispersion
Range
variation of mean
standard deviation
Variance
coefficient of variation
standard error of the mean
Today’s overwhelming number of techniques applicable to data analysis makes it extremely difficult to define the most beneficial approach while considering all the significant variables.
The analysis of variance has been studied from several approaches, the most common of which uses a linear model that relates the response to the treatments and blocks. Note that the model is linear in parameters but may be nonlinear across factor levels. Interpretation is easy when data is balanced across factors but much deeper understanding is needed for unbalanced data.
Analysis of variance (ANOVA) is a collection of statistical models and their associated estimation procedures (such as the "variation" among and between groups) used to analyze the differences among means. ANOVA was developed by the statistician Ronald Fisher. ANOVA is based on the law of total variance, where the observed variance in a particular variable is partitioned into components attributable to different sources of variation. In its simplest form, ANOVA provides a statistical test of whether two or more population means are equal, and therefore generalizes the t-test beyond two means. In other words, the ANOVA is used to test the difference between two or more means.Analysis of variance (ANOVA) is an analysis tool used in statistics that splits an observed aggregate variability found inside a data set into two parts: systematic factors and random factors. The systematic factors have a statistical influence on the given data set, while the random factors do not. Analysts use the ANOVA test to determine the influence that independent variables have on the dependent variable in a regression study.
Sir Ronald Fisher pioneered the development of ANOVA for analyzing results of agricultural experiments.1 Today, ANOVA is included in almost every statistical package, which makes it accessible to investigators in all experimental sciences. It is easy to input a data set and run a simple ANOVA, but it is challenging to choose the appropriate ANOVA for different experimental designs, to examine whether data adhere to the modeling assumptions, and to interpret the results correctly. The purpose of this report, together with the next 2 articles in the Statistical Primer for Cardiovascular Research series, is to enhance understanding of ANVOA and to promote its successful use in experimental cardiovascular research. My colleagues and I attempt to accomplish those goals through examples and explanation, while keeping within reason the burden of notation, technical jargon, and mathematical equations.
Statistical tests of significance and Student`s T-TestVasundhraKakkar
Statistical tests of significance is explained along with steps involve in Statistical tests of significance and types of significance test are also mentioned. Student`s T-Test is explained
The ppt cover General Introduction to the topic,
Description of CHI-SQUARE TEST, Contingency table, Degree of Freedom, Determination of Chi – square test, Assumption for validity of chi - square test, Characteristics , Applications, Limitations
Measures of dispersion
Absolute measure, relative measures
Range of Coe. of Range
Mean deviation and coe. of mean deviation
Quartile deviation IQR, coefficient of QD
Standard deviation and coefficient of variation
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdfRavinandan A P
Biostatistics, Unit-I, Measures of Dispersion, Dispersion
Range
variation of mean
standard deviation
Variance
coefficient of variation
standard error of the mean
Abstract: This PDSG workshop introduces basic concepts of statistics. Concepts covered are mean (average), median, mode, standard deviation discrete vs. continuous, normal distribution, sampling distribution, Z-scores and boxplots.
Level: Fundamental
Requirements: No prior programming or statistics knowledge required.
Chapter 4
Summarizing Data Collected in the Sample
Learning Objectives (1 of 3)Distinguish between dichotomous, ordinal, categorical, and continuous variablesIdentify appropriate numerical and graphical summaries for each variable typeCompute a mean, median, standard deviation, quartiles and range for a continuous variable
Learning Objectives (2 of 3)Construct a frequency distribution table for dichotomous, categorical, and ordinal variablesProvide an example of when the mean is a better measure of location than the medianInterpret the standard deviation of a continuous variable
Learning Objectives (3 of 3)Generate and interpret a box plot for a continuous variableProduce and interpret side-by-side box plotsDifferentiate between a histogram and a bar chart
Variable TypesDichotomous variables have two possible responses (e.g., yes/no).Ordinal and categorical variables have more than two responses, and responses are ordered and unordered, respectively.Continuous (or measurement) variables assume in theory any values between a theoretical minimum and maximum.
BiostatisticsTwo areas of applied biostatisticsDescriptive statistics—summarize a sample selected from a population Inferential statistics—make inferences about population parameters based on sample statistics.
VocabularyData elements/data points Subjects/units of measurementPopulation versus sample
Sample vs. Population Any summary measure computed on a sample is a statistic.Any summary measure computed on a population is a parameter.
n = Sample Size
N = Population Size
Example 4.1.
Dichotomous Variable
Frequency Distribution Table
Relative Frequency Bar Chart for Dichotomous Variable
Sample: n = 50
Population: Patients at health center
Variable: Marital status
Categorical Outcome (1 of 2)Marital StatusNumber of PatientsMarried24Separated5Divorced8Widowed2Never married11Total50
Categorical Outcome (2 of 2)
Frequency Distribution Table Marital StatusNumber of
Patients (f)Relative Frequency
(f/n)Married240.48Separated50.10Divorced80.16Widowed20.04Never married110.22Total501.00
Frequency Bar Chart
Sample: n =50
Population: Patients at health center
Variable: Self-reported current health status
Ordinal Outcome (1 of 2)Health StatusNumber of PatientsExcellent19Very good12Good9Fair6Poor4Total50
Ordinal Outcome (2 of 2)
Frequency Distribution Table Heath StatusFreq.Rel. Freq.Cumulative Freq.Cumulative Rel. Freq.Excellent1938%1938%Very good1224%3162%Good918%4080%Fair612%4692%Poor48%50100%50100%
Relative Frequency Histogram
Example 4.2.
Ordinal Variable
Frequency Distribution Table
Relative Frequency Histogram
for Ordinal Variable
Assume, in theory, any value between a theoretical minimum and maximumQuantitative, measurement variables
Continuous Variable (1 of 9)
Population: Patients 50 years of age with coronary artery diseaseSample: n = 7 patientsOutcome: Systol ...
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
2. Learning objectives
The students will learn about :
• Range and variability
• Standard deviation
• Calculation of standard deviation from
ungrouped and grouped data
• Variance
• Standard error of mean
• Confidence limits of the mean
3. Range and variability
• Variation occurs in the populations, so the samples
(e.g measurement of height, weight, length etc)
collected from the population shows variability.
• Simplest measure of variability in a sample is called
range.
• Range takes into account only the two most extreme
observations of the sample. So it can be used where
measurements are few. Its use is limited.
• e. g. height of girls (n=10) in the ranges from 4ft to
5.5ft
4. Standard deviation
• First introduced by Karl Pearson in 1893
• Standard deviation is a fundamental property of Normal
probability curve, 68.26% of the observations is included by one
standard deviation on either side of the axis of symmetry
(=mean).
• Therefore, standard deviation is a very useful comparative
measure of variation about a mean value of sample.
• If sample includes the entire population, the symbol of standard
deviation is σ (sigma). It is calculated by the formula
σ = √ ∑ (x- μ )2/N
• Where, x = value of observation
μ = population mean
∑ = the sum of
N = number of sampling units in the population
5. Standard deviation
• It is rare to collect sample from the entire population. So
samples are collected from a portion of a population. In this
case, symbol σ is replaced by ‘s’. The formula for calculating s
becomes
• s = √ ∑ (x- x̅)2 /n-1
• Where x̅ = sample mean
• n = number of sampling units in the sample.
• (x- x̅ ) = deviation from the mean
6. Calculation of standard deviation of
ungrouped data
1. Calculate the mean (simple average of the
numbers).
2. For each number: subtract the mean. Square the
result.
3. Add up all of the squared results.
4. Divide this sum by one less than the number of data
points (n - 1).
5. Take the square root of this value to obtain the
sample standard deviation .
7. Calculation of standard deviation
• Following is the wing length measurements (mm)
• 81,79,82,83,80,78,80,87, 82,82
1. Mean x̅ = ∑ x/n =814/10 =81.40 mm
2. (81-81.4)2 = 0.16
(79-81.4)2 = 5.76
(82-81.4)2 = 0.36
(83-81.4)2 = 2.56
(80-81.4)2 = 1.96
(78-81.4)2 = 11.56
(80-81.4)2 = 1.96
(87-81.4)2 = 31.36
(82-81.4)2 = 0.36
(82-81.4)2 = 0.36
3. ∑ (x- x̅)2 = sum of squares of deviations = 56.4
8. Calculation of standard deviation of
ungrouped data
4. Sum of squares/n-1 = ∑ (x- x̅)2 /n-1 =56.4/9 = 6.27
5. Standard deviation s = √6.27 = 2.50 mm
9. Calculation of standard deviation from
grouped data
• Formula for standard deviation of grouped data is
• s = √ ∑ f (x- x̅)2 /n-1
• Wing length measurements:
• Calculation continued on next slide…..
10. Calculation of standard deviation from
grouped data
Class (x)
mm
Frequency f (x- x̅)2 f (x- x̅)2
68 1 36 36
69 2 25 50
70 4 16 64
71 7 9 63
72 11 4 44
73 15 1 15
74 20 0 0
75 15 1 15
76 11 4 44
77 7 9 63
78 4 16 64
79 2 25 50
80 1 36 36
∑ f (x- x̅)2 = 544
n = 100
s = √ ∑ f (x- x̅)2 /n-1
= √544/99
= √5.49 =2.34 mm
11. Variance
• Variance is the square of standard deviation
• Conversely, standard deviation is the square root of
variance
• s = √s2, and
• s2 = ∑ (x- x̅)2 /n-1
12. Standard Error of Mean
• Standard error of the mean (SEM) measures how far a sample
mean deviates from the actual mean of a population
• S.E. = sample standard deviation/√number of sampling units
• S.E. calculated from previous data of wing length=2.34/√100 =
2.34/10 = 0.234
13. Confidence limits of the mean
• The standard error of the mean shows how good is the estimate
that the sample mean is close to population mean.
• Referring to the normal distribution curve, We are 68% confident
that population mean lies within ± 1 S.E. of sample mean.
• We want to be more sure, so 95% or 99% limits are generally
used. These can be obtained by multiplying S.E. (standard error)
by z score (of Normal probability curve)
• 95% of observations fall within ± 1.96 S.E (z= ± 1.96).
• 99% of observations fall within ± 2.58 S.E (z= ± 2.58).
• The intervals ± 1.96 S.E and ± 2.58 S.E are called 95% and 99%
confidence limits respectively.
• 95% confidence limits of wing lengths are 74± (1.96X0.234)
=74.00±0.459