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# AGR 306 Final Review

### Review of Epidemiology Terms and Questions for Final Exam

Question | Answer |
---|---|

______ has traditionally been applied to human diseases | Epidemiology |

In the causal pie model, the _______ is depicted by the entire pie | Sufficient Cause |

The study of ecosystems is known as ______ | Ecology |

______ is the indirect method of gaining insight into natural processes | Induction |

______ investigations are the component of the epidemiological process which contain the natural history of disease and the causal hypothesis testing | Qualitative |

_____ is the type of study where one group is exposed to risk factors compared to a group which is not exposed to risk factors | Cohort |

_____ is a component of the causal pie model which is not a biologically stable characteristic | Strength |

____ are diseases shared by lower animals and man | Zoonoses |

What are necessary pieces of information for a disease control or eradication program? | - Amount in population - Facilities needed to control disease - Natural history of disease - Factors associated with its occurrence - Cost/benefits to control |

What are Hill's causal criteria? | 1 - Strength; 2 - Consistency; 3 - Specificity; 4 - Temporality; 5 - Biological gradient; 6 - Plausibility; 7 - Coherence; 8 - Experimental evidence; 9 - Analogy |

What is causation and why is it important to epidemiology? | Affect something has on other things; Certain conditions/events bring about other conditions/events; Realizing the cause of disease will help prevent an epidemic in both human and animal species |

Bonus: In what state was the BSE case found over the summer? | Alabama |

The first step in formulating a causal hypothesis is gaining ____ information | Descriptive |

The key part of defining epidemiology is describing disease occurrences in a _____ | Population |

_____ traditionally referred to disease outbreaks in poultry | Epornitics |

A disease which can be shared by lower animals and man is ____ | Zoonosis |

The study of ecosystems is known as _____ | Ecology |

The entire pie of the causal model 1 is known as a ____ cause | Sufficient |

_____ is not a biologically stable characteristic | Strength |

The goal of epidemiology is to effectively ____diseases | Control |

A(n) ____ is an examination of aggregate units | Survey |

_____ is identifying that certain actions bring about other actions | Causation |

_____ is the indirect method of gaining insight into natural processes | Induction |

_____ is the aggregate of all facts relating to animals & plants in an environment | Natural History |

_____ are variables which increase the likelihood of a disease | Risk Factors |

_____ is the quantitative process of making routine observations | Monitoring |

_____ is the association of variables whereby one variable impacts another without opposition | Direct |

_____ is produced in casual model #2 in order to show the levels of causal factors | Web of causality |

_____ is the time between a component cause occurring and the completion of the sufficient causation model | Induction time |

_____ is the effect of an extraneous variable which can wholly or partially explain an apparent association | Confounding |

_____ are defined as observable events which can vary | Variables |

[Method of deriving a hypothesis] A single causal factor found in 1 of 2 different circumstances | Difference |

[Method of deriving a hypothesis] Comparison of unknown disease to an understood disease | Analogy |

[Method of deriving a hypothesis] A single causal factor similar among many circumstances | Agreement |

[Method of deriving a hypothesis] Frequency of a factor varies continuously with a disease | Concomitant variation |

[Type of study] Compare a group of heathy to a group of sick individuals | Case-Control |

[Type of study] Compare a group which is exposed to one which is not | Cohort |

[Type of study] Investigator can randomly allocate animals to groups | Experimental |

[Type of study] Investigates relationships between disease and possible cause | Cross-Sectional |

What are the four types of surveys? | Cross-Sectional; Longitudinal; Retrospective; Screening |

What are Koch's Postulates? | 1 - Must be in every case; 2 - Transmissible; 3 - Cannot be in a different disease |

Name the sub-disciplines of epidemiology. | Clinical; Computational; Genetic; Field; Participatory; Molecular |

What are the three methods diseases of known origin can be diagnosed? | Signs exhibited; Lab testing; Other diagnostic tests |

What are the four methods by which hypotheses can be accepted? | Tenacity; Authority; Intuition; Scientific inquiry |

Name and briefly describe the types of epidemiological investigation. | Experimental: observe and analyze data from groups that can be controlled; Descriptive: observe and record; Cross-Sectional: investigate relationship between disease and possible cause; ... |

Name and briefly describe the types of epidemiological investigation (cont.) | Analytical: Analysis using diagnostic and statistical measures; Theoretical: Use math simulation models |

What are the five objectives of epidemiology? | Determine origin of disease with known cause; Investigate/control disease with unknown cause; Acquire information on ecology and natural history; Plan, monitor, assess; Assess economic benefit |

What are the necessary pieces of information for a disease control or eradication program? | Amount in population; Factors associated; Facilities needed; Costs and benefits |

What are 4 of Evan's rules? | Higher disease rate in exposed vs. not; Response rate increases if exposure increases (1 sting vs. 100); Higher exposure rate in infected vs. not; Modification decreases the amount of disease in the population |

When were Koch's Postulates published? | 1892 |

Bonus: Where did Dr. Harrelson complete his PhD? | New Mexico State University |

____ is the probability of individuals with a disease remaining alive for a length of time | Survival |

A(n) ____________ is the term utilized when the period of risk for a disease is brief | Attack Rate |

A _________ is a population with no movement into or out of it | Closed population |

_____ is the total mortality rate for all diseases within a population | Death rate |

_____ is the basic term for the amount of a disease in a population | Morbidity |

_____ is when a disease is continuously present at high levels | Hyperendemic |

Usual frequency of occurrence of a disease in a population | Endemic |

Number of disease cases at a given time | Prevalence |

Occurrence of a disease to higher than expected levels | Epidemic |

Number of new cases occurring over a given time | Incidence |

What are the common methods utilized to display demographic, morbidity, or mortality data? | Bar chart; Circle chart; Time trend graph; Time line graph; Table |

What are methods which can be utilized to assess the population size of contiguous animal populations? | Aerial count; Ground count; Counting tracks; Dung sampling; Catch-release-recatch (tagging); Distance sampling |

What are common types of maps utilized to display health data? | Proportional circle map; Base map; Point map; Distribution map; Chorophelethic map; Isophethic map; GIS |

Geographical formations and vegetation which can impact spatial animal distribution is known as a _____ effect | Location |

A(n) ______ infection is when clinical signs are not exhibited by a host | Subclinical/Invisible |

A ____ factor is one which exerts a major influence on disease causation | Primary |

The __________ is the total mortality rate for all diseases in a population | Mortality (Death) rate |

When a population is at risk for a brief amount of time, it is known as a(n) _________ | Attack rate |

A disease outbreak which is irregular and haphazard is _____ | Sporadic |

______ are often used to depict age | Population pyramids |

A(n) ______ is the term for any noxious stimuli | Stressor |

A(n) ____ population has no movement into or out of it | Closed |

The basic term to describe the amount of a disease is _____ | Morbidity |

____ is the stage of infection where animals shed disease but do not readily exhibit clinical signs | Carrier |

_____ is the type of climate which occurs in a small, confined space | Microclimate |

_____ is the general term for any characteristic which affects the health of a population | Determinant |

_____ is a widespread epidemic which usually affects large populations | Pandemic |

_____ is the amount of a disease in a population at a given time | Point Prevalence |

_____ is an alteration of the nucleic acid sequence of a cell or virus | Mutation |

_____ is the interdependent operation of factors to produce (or prevent) an effect | Interaction |

_____ is when a disease is constantly present in a population | Endemic |

_____ is the ability of an infectious agent to cause a disease | Virulence |

_____ is the re-assortment of genome segments during genetic exchange between organisms | Recombination |

Determinants which are external to the host | Extrensic |

Release of DNA from one bacteria to another | Transformation |

Transmission of genetics via conjugal methods | Conjugation |

Transfer of genetic material due to bacteriophages | Transduction |

Determinants which are internal to the host | Intrinsic |

(# of new cases - # of deaths) / # of new cases | Survival |

# of deaths due to disease / sum of time at-risk of dying | Mortality rate |

# of new cases in a time period / sum of at-risk time | Incidence rate |

# of deaths / # of diseased animals | Case fatality |

# of individuals affected / # of at-risk individuals | Prevalence |

What are the types of genotypic changes to virulence? | Mutation; Recombination; Conjugation; Transduction; Transformation |

What are the three parts of the general adaptive syndrome model? | 1 - General alarm reaction, 2 - Phase of resistance, 3 - Phase of reactions |

Name and briefly describe the four methods in which sex of the animal can be a disease determinant. | Hormonal - predispose animals to disease; Occupational - pasture vs working; Social/Ethological - behavior pattern; Genetic - sex-linked disorders |

What are the 3 basic types of rates or proportions? | Crude measures; Specific measures; Standardized/Adjusted measures |

What are the three classifications of infections? | Opportunistic pathogens; Common virus; Specific infectious diseases |

What are three ways in which husbandry can be a disease determinant? | Diet; Housing; Management |

What are the three categories of genetic disorders? | Mendelian (simply inherited); Chromosomal; Multifactorial |

What are the three determinants which make up the "triad" of disease occurrence? | Host; Agent; Environment |

Bonus: What disease did we discuss as an example of a Mendelian genetic disorder? | Spider Lamb |

A(n) _____ is the most widely used statistical measure | Average |

A ________ is also known as the root-mean-square | Standard deviation |

Typically, raw data is collected in _____ order | Random |

______ is the representativeness or validity of an average | Dispersion |

A(n) ______ is used to reorder data from the smallest to the largest value | Array |

_____ is a systematic error in the design, conduct, or analysis of an experiment which renders the results invalid | Bias |

Average value identifying the most common observation | Mode |

Average of the smallest and largest value in a data set | Midrange |

Most widely used measure of central tendency | Mean |

Value which is a place average; middle value of a data set | Median |

What are the four major types of bias? | Bias based on confounding; Interviewer bias; Measurement bias; Selection bias |

What are the two methods of presenting a frequency distribution we discussed in class? | Histogram; Frequency polygon |

What are the three measures of data dispersion discussed in class? | Standard deviation; Range; Quartile deviation |

_____ is generally used to draw conclusions about the composition of a sample from the population | Probability |

The _____ interval is a range of values around a sample estimate | Confidence |

_____ events means all outcomes of an experiment are equally likely to occur | Equiprobable |

_____ is a systematic error in the design, conduct, or analysis of a study | Bias |

The _____ frequency provides a numerical estimate of the probability of an event | Relative |

A _____ measures the association between 2 random variables | Correlation |

_____ is a place average | Median |

A(n) ____ is used to summarize data from the smallest to largest value | Array |

The _____ distribution describes the number of events over a set time frame | Poisson |

Bias _____ be corrected if it occurs | Can |

_____ is the term used when one outcome occurs which precludes any other event | Mutually exclusive |

_____ is the most widely used measure of central tendency | Arithmetic mean |

_____ is the measure of dispersion which is also known as the root-mean-square | Standard Deviation |

_____ is the statistical hypothesis of no effect or no difference | Null hypothesis |

_____ is the typical order in which data is collected | Random |

_____ is any object that can take on a range of values | Variable |

_____ is the type of distribution based on only 2 discrete outcomes | Binomial |

_____ is the type of experimental error represented by alpha | Type I |

_____ is the measure of dispersion which is used only with the median | Quartile Deviation |

_____ is any ordered sequence of a group or set of things which can be calculated by the multiplication rule | Permutation |

Any process of observing or obtaining data | Experiment |

Estimate of a population variable | Parameter |

Representative subset of a population | Sample |

Elementary units which comprise a population | Observations |

Basic unit to which treatments are applied | Experimental unit |

Estimate of sample variables | Statistic |

What are the five steps to testing a hypothesis? | 1 - State the null and alternative hypotheses; 2 - Determine sample distribution; 3 - State alpha and determine critical value (significance); 4 - Compute value of the test statistic using sample data; 5 - Make decision about hypothesis |

What are the three kinds of problems suggested by studying probability? | Defining and interpreting what probability is; Utilizing known probabilities to calculate others; Obtaining numerical probabilities |

[Type of bias] When ignoring a single/few factors drastically changes analysis | Bias due to confounding |

[Type of bias] Where an interviewer's opinion(s) may affect reporting of data; Especially with surveys and similar types of data collection procedures | Interviewer bias |

[Type of bias] Involving inaccurate measurements or the misclassification of animals as diseased or non-diseased | Measurement bias |

[Type of bias] Where animals selected for study have systematically different characteristics from those that are not selected for study | Selection bias |

What are the five types of sampling methods? | Random; Systematic; Clustered; Stratified; Sequential |

What are the characteristics of the normal distribution? | Bell shaped curve; 68% of data between mean and one standard deviation; 95% of data between mean and two standard deviations; 99.7% of data between mean and three standard deviations |

What are the three basic properties of probability? | Falls between zero and one; Sum of all probabilities is equal to one; Probability of compound events is equal to the sum of all events that are not A |

What two methods, other than a table, can be utilized to express a frequency distribution? For each method, what is the advantage to using it? | Histogram - see shape of data; Frequency polygon - compare two or more distributions |

In terms of hypotheses, what is our goal in research? | Reject the null hypothesis and determine alternative hypotheses as true |

How does calculation of the mean differ when we have grouped data as opposed to ungrouped data? | Easier to find the biggest and smallest value; No raw data points in grouped data; Use the group mean as a proxy |

[Type of experiment] Design where experimental units are randomly assigned to treatments without blocking; Simplest experimental design | Completely randomized design |

[Type of experiment] Create blocks which represent time, location, or experimental material; Randomly apply treatments to blocks and repeat in multiple blocks; Blocks may be similar units which allow for unbiased data | Randomized block design |

[Type of experiment] Uses few experimental units which receive all treatments in random order; Have a break between treatments | Latin square |

Bonus: The coefficient of determination is represented by what? | r^2 |