Habitat destruction is when a natural habitat is altered or destroyed so that it can no longer support the species that lives there. A habitat is commonly defined as the environment where a particular species lives and habitat destruction can cause the migration or extinction of a species. Causes of habitat destruction include things like human activity, climate change, natural disasters and geological processes. (02:36)
How to Study for a Math Test
This 2:30 minute long video is about how to study for a math test, review as much homework as possible, be familiar with
the terminology and do a self test out of a text book to practice
solving math problems. This is a college level video, but useful for most all grade levels.
Biodiversity is the amount of variety of organisms in a particular area and is typically used to measure the "health" of an ecosystem. Biodiversity usually encompasses genetic diversity (variations within individual populations), ecosystem diversity (within ecosystems) and landscape diversity (range of differing ecosystems within an area). (03:46)
Natural Resource Depletion
Natural resource depletion is loosely defined as when resources are used up in an area. Non-renewable resources (things like oil and trees) will eventually be depleted while renewable resources (things like wind and sun) typically are not entirely depleted. (01:23)
How a Nuclear Reactor Works
In this short video you will learn how a nuclear reactor works. The narrator tells the sequence of events that are involved. (00:50)
Population density is loosely defined as the number of organisms in an area divided by the amount of area. Population density is typically measured in kilometers squared. High population density can cause increased competition for resources while low population density can cause problems with finding mates and inbreeding. (01:37)
Dispersion is the spreading of a population or organism away from its parents and happens when organisms are looking for additional resources or as an adaptation to environmental changes. Dispersion is influenced by various environmental factors such as temperature or terrain. Animals disperse by moving, while plants have seed dispersal.
Population growth is loosely defined as the change in the amount of individuals of a specials in an area over time. To find the growth rate of a population, we take the number of individuals moving into an area and subtract the number of individuals moving out of an area by taking the birth rate, adding the immigration rate and subtracting the death rate and emigration rate. Two types of population growth are exponential and logistic growth.
The atmosphere is the layer of air that surrounds the Earth and is comprised mainly of Nitrogen and Oxygen. The atmosphere also contains traces of gases like carbon dioxide, neon, helium, etc. There are 5 main layers of the atmosphere: the troposphere, the stratosphere, the mesosphere, the thermosphere and the exosphere. (04:10)
Japan - The 'Despised' Ainu People
An insightful report on racial discrimination in Japan. "A small boy denies his Ainu ancestry for fear of being bullied in a society where conformity is valued above all else. The Ainu people of the northern island of Hokkaido are despised by the rest of Japan. Different in appearance and language they have suffered more than a century of discrimination." (12:52)
Endangered species are defined as a species that is in immediate danger of going extinct. Species become endangered through a number of factors including disease, human activities and competition with other species. Examples of endangered species include the mountain gorilla and the black rhino. Another category is something called a threatened or vulnerable species. These are species that are in danger in the near-term. (03:01)
Behavioral ecology is the study of ecological and evolutionary causes of behavior in organisms. Behavior is influenced by genetics and the environment and should increase the reproductive fitness of a species. Common behaviors studied including things like learning, communication, foraging, reproductive strategies and social behaviors. (04:38)
Population ecology is the study of populations and their interactions with the environment. A population is a group of individuals of a species in a particular area. Population ecology studies things like population growth, selection strategies, population distribution, demographics and how populations evolve and adapt. (02:26)
"Our Little Ghost" by Louisa May Alcott (poetry reading)
Maybe this is a poem about a living child expressed in a somewhat macabre way, but on close examination that seems less likely. Louisa May Alcott is better known for her novel Little Women, published in 1865, one of the first novels of the movement called Literary Realism. When reality is harsh, literature and art tend to be idealised. Little Women is about a family of four sisters. Beth, the youngest, becomes ill and she actually dies. http://en.wikipedia.org/wiki/Louisa_May_Alcott http:/
Rescue operation in Sendai
Parts of Sendai burns as rescue workers search for survivors amidst the rubble and debris in Japan.
Protesters clash with police in Bahrain
Riot police face off against protesters near Pearl Roundabout as they attempt to block a main thoroughfare to the financial district.
Cleanup begins in Japan after quake
Residents in Japan are returning to their shattered neighborhoods and taking stock of the damage from Friday's devastating 9.0 magnitude earthquake
Libyan rebels face heavy air assault
Rebels are pushed back after being outgunned at Ras Lanuf and Uqaylah but fight to hold Ajdabiyah.
Clashes turn violent in Yemen
At least one person is dead and several injured as Yemen police open fire on protesters in Sanaa. Deborah Lutterbeck reports.
Prayers for Japan
The Pope calls on the faithful to pray for the victims of Japan's earthquake as citizens of Germany and Russia offer condolences. Deborah Lutterbeck reports