midterm II cambell population structures and distributions

Question 1

what is the trend of the us population distribution?

Answer 1

there is a large aging population

Question 2

what is the trend of practitioner numbers in alberta?

Answer 2

increase

Question 3

what is the trend of vet practitioners female vs male?

Answer 3

many more females entering

Question 4

what has been the shift of the urban/rural population shift in canada

Answer 4

it has gone from 80% rural to 80% urban and the remaining 20% in rural regions –most don’t live on farms

Question 5

what is the population distribution of cow-calf operators?

Answer 5

the vast majority are older males; there are very few young operators

Question 6

what is the difference in appearance of the more developed regions vs the less developed regions in terms of population structure?

Answer 6

the less developed regions have a much large young population and a small older population whereas the developed countries have a a much smaller young population

Question 7

who was the man who talked in the video about populations and distributions?

Answer 7

hans rosling

Question 8

what is the epidemiological triad?

Answer 8

it is interaction between the host, the agent and the environment

Question 9

can population structure and social organization affect parasite transmission and prevalence?

Answer 9

yes

Question 10

at the individual level, what gives structure to the social systems?

Answer 10

age, sex, reproduction rate, relatedness, position in dominance hierarchy, social interactions , patterns of space use

Question 11

at the group level, what determines the social systems of animal populations?

Answer 11

group sizes, whether the animals are solitary and only interact during mating, whether they have monogamous pairs, whether they have social complex groups, whether huge aggregations of individuals occurs, and in food systems: the economics and structure of the agricultural industry or the urban environment may affect group sizes and populations distributions (e.g movement of large groups of cattle, movement of animals to different farms

Question 12

within a group: what gives structure to the social systems?

Answer 12

sex, age and social status, season

Question 13

do social system affect the pathogens/parasites and animal experiences?

Answer 13

yes

Question 14

how does a social system affect the pathogens/parasites an animal experiences?

Answer 14

it affects the number and types of contacts by affecting exposure and transmission rates

Question 15

the transmission of a parasite among groups depends on

Answer 15

group size, composition, territoriality, levels of inter-group movement and contact

Question 16

what are within group factors that influence the transmission of a parasite?

Answer 16

gender, age, dominance, the presence of superspreaders

Question 17

what are examples of disease that show a bias toward a particular gender?

Answer 17

bovine tuberculosis and chronic wasting disease show a higher prevalence in males

Question 18

why do bovine tuberculosis and CWD show a higher prevalence in males?

Answer 18

larger animals are more susceptible to vectors, there are sex related differences in home ranges, there are sex related differences in physiology/behavior, such as during breeding seasons, when males have higher stress levels as well as the fact that hormones can have an effect on the immune system

Question 19

generally, what are reasons why disease show different prevalences in male vs female?

Answer 19

1) mating behaviour can have important implications for disease exposure
2) polygamy is a common mating system among mammals
3) variance in mating success (socially dominant males mate with more females)
4) polygamy–more likely to spread STD’s such as trichomoniasis

Question 20

generally, what are reasons why disease show different pre valances in different age groups?

Answer 20

1) if the pathogen does not kill the host, the prevalence will often increase with age (e.g tuberculosis, CWD, maedi-visna virus in sheep, john’s disease in cows)
2) if antibody titers persist, seroprevalence is also likely to increase with age
3) if hosts recover from infection and become immune, juveniles may have a higher prevalence than adults
4) many adults may hav already been exposed and recovered (parvo virus, many parasites, calici-virus in cats)
5) infants may be initially protected by maternal immunity and become susceptible when passive immunity wanes (many disease occur when maternal-derived immunity in calves is starting to drop and they are still developing their own immunity

Question 21

generally, what are reasons that social dominance can result in different prevalences in different groups?

Answer 21

it can affect exposure rates and stress levels and chronic stress can impair the immune system
however, these can be complicated by breeding behaviour, rank stability and coping mechanisms for subordinates

Question 22

how might super spreaders be identified

Answer 22

identification of social networks, other diagnostic tools to identify highly infectious individuals

Question 23

what is the mechanism of being a “super-spreader”?

Answer 23

it can be physiological with higher levels of secretion of a pathogen (true of johns disease) but can also get super spreaders because of their behaviour (e.g sharing of drugs or sexual behaviour)

Question 24

what are intergroup factors that effect the spread of disease?

Answer 24

territoriality (esp wildlife species)
group size and population density
economic organization of the agricultural industry

Question 25

how can territoriality alter the likelihood of disease occurrence?

Answer 25

1) aggressive encounters may increase exposure to disease
2) defensive behaviours are energetically costly and may increase stress
3) biting and scratching are potential transmission mechanisms
4) may reduce transmission by reducing contact between individuals and groups

Question 26

how does group size and population density affect the prevalence of disease?

Answer 26

1) it directly affects contact rate
2) disease maintenance and transmission
3) function of industry economics and structure
4) urban habitats
5) size of home ranges
6) movements and distances travelled
7) barriers to dispersal
8) habitat requirements

Question 27

how does economic organization of industry impact the rates of contact and disease transmission?

Answer 27

1) herd sizes
2) herd densities and inter-herd contact
3) animal movement
4) inter-species mixing and within-species mixing
5) cross border movement of animals

Question 28

what is an example of how the beef cow farming has changed and how this impacts rate of contact and disease transmission

Answer 28

the beef farm numbers have been decreasing, but cow numbers have been increasing and the so the animals per farm has been increasing, which likely means that there is a higher density of animals and a higher contact rate

Question 29

what is an example of how the structure of the beef industry means that there is a high rate of contact of animals?

Answer 29

there are a number of farms but fewer feedlots and even fewer slaughter houses
there are 70 000 cow calf producers, 200 feedlots and 2 major beef processors

Question 30

what is the link between making diagnoses on individual animals and population distribution?

Answer 30

the question we ask in a history and physical exam are trying to sort out what population the animal belongs to. these risk factors help us narrow down our diagnosis

Question 31

what is the definition of a clinical diagnosis?

Answer 31

an effort to recognize a class or group to which a patient’s illness belongs so that based on our prior experience with that class, the subsequent clinical acts we can afford to carry out and the patient is willing to follow will maximize the patient’s health

Question 32

what are the three elements of disease

Answer 32

the disease or target disorder
the illness
the predicament

Question 33

what is the disease or target disorder? (element of disease)

Answer 33

what is read about in medical textbooks and is the objective of the diagnosis

Question 34

what is the illness of the animal? (element of disease)

Answer 34

the cluster of signs and symptoms

Question 35

what is the predicament (element of disease)

Answer 35

the environment, client limitations etc in which the animal is situated

Question 36

the act of a clinical diagnosis___________

Answer 36

focuses on the second element in order to identify the first, while keeping an eye on the third

Question 37

why are most medical textbooks backwards?

Answer 37

because they start with the target disorders and go backward to the illnesses (the exact reverse of a diagnostic process)

Question 38

what is the strategy of clinical diagnosis called pattern recognition?

Answer 38

it is the realization that the patient’s presentation conforms to a previously learned picture or pattern of disease; it is usually visual but can be auditory or by door
the diagnosis conclusion is made quickly
it is reflexive not reflective
it’s use increases with experience
it could be said to be the start of the diagnostic process
it results in several possible diagnoses, rather than a single one

Question 39

what is the strategy of clinical diagnosis called the arborization strategy?

Answer 39

it is a flow chart of a large number of potential preset pathways of diagnostic inquiries
it must be logical and include all relevant causes
used when diagnosis is delegated to others
may help to triage cases
best for conditions with discrete and accurate date
promotes careful methodical workup
excellent tool for uncommon conditions
can be cumbersome and inefficient
may be poor at handling atypical case presentations

Question 40

what is the strategy of clinical diagnosis called the exhaustive method

Answer 40

it is the method where a complete history and physical is taken; it is a painstaking invariant search for all medical facts about the patient; it is followed by sifting through data; many students are taught that this is the right way to diagnose; it is the method of the novice, abandoned by experience; it may be useful in very complex cases and avoids the failure to look for the problem but it is usually very inefficient and not all history questions are relevant in all situations; this is not the method that most clinicians use; it has a laboratory counterpart

Question 41

when randomized patients received 50 tests as soon as they arrived did this improve any factors?

Answer 41

no it did not improve mortality, morbidity, duration of monitoring, disability, medical opinions of the patient’s progress or length of stay

Question 42

what is the hypothetico-deductive strategy?

Answer 42

it is the strategy used virtually by all clinicians all the time and it involves the formulation of a short list of potential diagnoses or actions based on early clues; it then uses other diagnostic strategies to reduce the length of the list

Question 43

where do the hypotheses for the hypothetico-deductive strategy come from?

Answer 43

they come from pattern recognition; they are the explanatory ideas that tie our understanding of biology to signs and symptoms; this list is usually formed within the first minute of work up; as clinicians generate the list, they are performing history taking or a physical exam that reduces the length of the list

Question 44

what other diagnostic methods are used to shorten the list of hypotheses?

Answer 44

history and physical examination; x-rays, laboratory tests, etc

Question 45

what did barrows et. al find in his study about hypotheticodeductive strategy?

Answer 45

that clinicians generate first hypothesis within 28 sec; correct hypothesis within 6 min; clinicians right 75% of time; average 5.5 hypotheses per case

Question 46

what are some limitations of the hypotheticodeductive strategy?

Answer 46

clinicians subconsciously keep list to 3 or 4
most clinicians seek evidence rather than rule out
may not be most efficient technique

Question 47

how do we improve the hypotheticodeductive strategy?

Answer 47

master basic sciences; master directed unbiased selection acquisition and interpretation of clinical data and paraclinical data that will best shorten list; complete physical exam is really an all encompassing set of sub-routines