Transcript Hantavirus- Yosemite

Hantavirus- Yosemite
K Coleman
Starting Question
• Have you been outside of the U.S.? What
would you worry about when touring outside
of the country?
Yosemite National Park Tourism
• Which biome is this?
Yosemite and the dreaded Hantavirus!
• 4 min videos
•
•
http://www.youtube.com/watch?v=iUimXBxOn90
http://www.youtube.com/watch?v=QymvUoPHmas&feature=related
• How could it affect tourism?
• How could it affect local species?
Disease Transmission Cycle
• What happens if you take out a chain?
Hantavirus
• Humans may become infected when they
inhale airborne virus or come into direct
contact with infected rodents or their urine,
feces, or nests
• Other mammal species (cats, dogs, coyotes)
may be infected through contact with rodent
hosts, but they are not known to transmit the
virus.
Transmission of Hantavirus
We could stop the spread of
hantavirus by:
a. Adding an agent
b. Providing a place of entry
c. Putting mice closer together
d. Removing the method of transmission
Hantaviral disease per year
Temperature
Temperature
Which would affect growth of the rodent population?
Wind
Nutrients
Soil
Which would affect growth of the rodent population?
All of the following are abiotic factors
EXCEPT:
a.
b.
c.
d.
Microorganisms
pH
Temperature
Hantavirus
Which of the following levels of biological
organization refers to both abiotic and biotic
factors?
a.
b.
c.
d.
Species
Population
Community
Biome
Disease Transmission Lab
• Grab one cup, write the number (1-6) on a separate
piece of paper
• One number in particular is infected
• Chose an eyedropper and place a small amount in
your cup with the matching number of a beaker’s
liquid
• Walk around the room and talk to a person
• When I say “Exchange!” squirt 4 eyedrops full into
that person’s cup. Record their number, do not
exchange with them again. Repeat twice.
• Then sit at the lab tables. Add the indicator to your
cup. Are you infected?
Disease Transmission Lab
Lab Questions for HW:
• Were you infected? How could you tell?
• Compare and contrast the results of this lab to
the disease transmission cycle.
• Provide a chart to determine the origins of the
disease. Who do you believe was responsible?
How could you test your hypothesis?
Growth Cycles of Rodents- Histograms
We’re interested in how populations of rodents
change. Population growth is dependent on the
number of births, the number of deaths, and the
number of individuals who enter or leave the
population.
Populations can follow two main patterns of growth:
exponential growth and limited growth. What would
these represent with rodents? What kinds of
conditions?
Hantavirus Enzootic Cycle
• single primary
host
• Sin Nombre virus,
hosted by the
deer mouse
• Low transmission
with unfavorable
environmental
conditions
• Exponential or
limited growth?
Logistic or Limited population
growth occurs when a
population's growth slows or
stops following a period of
exponential growth.
The limited availability of
resources, as well as
predation and disease all
limit the size of a population.
The maximum number of
individuals an environment
can support is called its
carrying capacity.
Epizootic Cycle
• virus is
maintained
and
transmitted
by host
reservoir
rodents by
aggressive
behavior,
biting
• Exponential
or limited
growth?
Exponential Growth
• Favorable mild winters and summer rainfall
may cause dramatic increases in rodent
populations
• Why would more rodents become infected?
• Where would they go?
• Exponential growth occurs when
a population reproduces at a
constant rate in the absence of
predation and disease as long as
resources are unlimited.
• Bacteria reproduce by binary
fission, as previously mentioned.
A bacterial population that
reproduces every 20 minutes
can grow to a population size of
4.27 x 1020 bacteria in one day.
http://www.ryancshaw.com/Files/micro/Animations/BacterialGrowth/PLAY_bacterial_growth.html
A population can grow exponentially under ideal
conditions. Which of the following would prevent
exponential growth from continuing?
a.
b.
c.
d.
The population is protected from predators.
The population is protected from disease.
The population runs out of food.
Reproduction occurs at a constant rate.
Exponential growth does not occur for long in nature,
and eventually all population growth slows down. A
population's maximum size is referred to as its
a.
b.
c.
d.
Limiting growth factor
Carrying capacity
Logistic growth
Exponential capacity
Pathogenesis
Affects on Population Density
Affects on Carrying Capacity
Density Dependent Factors
Density Independent Factors
The term habitat describes the specific area
- including biotic and abiotic factors - where an
organism lives within an ecosystem.
An organism's niche is the way it
lives and the role it plays in its
habitat. A niche includes all
aspects of where and how an
organism lives including:
the type of food it eats
how it obtains food
where it lives in its environment
example: tree, nest, hive, dam,
etc.
when and how it reproduces
If two populations have similar niches, they may
have to compete with each other for food or other
resources.
You and the student next to you cannot sit in the same seat
in this classroom, no two species can occupy the same niche
in the same environment at the same time.
The figure below shows three different species of warblers
feeding in different areas of the tree. Each species has its
own niche to avoid competition for food.
If an organism's habitat is like its home, an organism's
niche is most like which of the following?
a.
b.
c.
d.
Its address
Its community
Its job
Its structure
Communities interact in a
variety of different ways
that enable the organisms
within them to establish a
niche and shape the
ecosystem in which they
live.
The following are types of
interactions within
communities:
When organisms try to obtain food, water, space, sunlight, and other
resources in the same place at the same time, competition occurs.
Competition in nature drives biological evolution. The ability to
compete for resources is dependent upon whether an organism has
adaptations that enable it to thrive in its environment.
Trees in this forest are in competition for light. The tall, broad-leafed
trees outcompete the smaller trees for sunlight.
When organisms try to obtain food, water, space,
sunlight, and other resources in the same place at the
same time, competition occurs.
Competition in nature drives biological evolution. The
ability to compete for resources is dependent upon
whether an organism has adaptations that enable it to
thrive in its environment.
Predation occurs when one organism captures and
feeds on another organisms. The organism doing the
eating is the predator and the organism being eaten
is the prey.
Predation is a driving factor in co-evolution.
The prey evolves to better escape the
predator.
In turn the predator evolves to better
capture the prey.
Treatment and Prevention