Showing posts with label NOVA. Show all posts
Showing posts with label NOVA. Show all posts

Wednesday, October 10, 2012

Nutrition - Nova (Dying to be Thin)

Why do we eat? How do our bodies use the foods we eat? What organ or system in your body may not be getting enough of what it needs? This interactive feature from NOVA "Dying to Be Thin" Web site will fill you in. Just click on a body part or on the name of a nutrient to find out what you need to eat to stay healthy.
NOVA Body Needs
VIEW
  • Media Type: Interactive
  • Size: 121.0 KB
  • Level: Grades 3-8

  • Log in to Teachers' Domain to download, share, rate, save, and match to state standards.
Source: NOVA: "Dying to Be Thin" Web site
This resource can be found on the NOVA: "Dying to Be Thin" Web site.

Background

Standards of beauty have changed over the years. In the late 1800s, advertisers regularly used models who would be considered overweight by today's standards. Times have changed dramatically. Most Americans are exposed to thousands of media messages every day -- in magazines and newspapers, on television, on outdoor billboards, and over the Internet. These messages promote bodies that are thin and, in some cases, unrealistically proportioned, and they are creating a culture of young people who are obsessed with losing weight.

As a result of this obsession, many people have sworn off fat. They avoid eating fat in any form and, instead, obtain most of their calories from carbohydrates, like bread and pasta. For decades, doctors and health experts supported this fat-free nutritional strategy. Fat was the enemy, they said; it was the cause of obesity and heart disease. Carbohydrates were your friends and could be consumed, many thought, in mass quantities with few concerns about health consequences. Recent studies, however, have begun to reveal the flaws in this thinking.

A nutritional plan that shuns fat ignores this food's important role in the body. While fat's main purpose is to store energy, it serves many other functions as well. Either in its whole form or broken down into small molecules, fat does the following: provides insulation, builds membranes, aids digestion, promotes proper nervous system function, regulates hormones, keeps the skin healthy, and aids the chemical communication between cells. And these are just a few of the important things that fat does for us. Still, many people continue on a fat-free path.

Somewhat surprisingly, fat-free diets often result in the accumulation of excess body fat. Carbohydrates, including sugars and starchy foods, provide the body's most efficient form of energy. They are broken down quickly into glucose, the sugar that cells need in order to function. This is why energy bars used by athletes are made up primarily of carbohydrates: They are quickly broken down in the stomach, and the resulting sugars are easily transported throughout the body via the bloodstream.

When the body is active at high intensity for long periods of time, carbohydrates must be eaten regularly to provide the cells with the energy they need. Carbohydrates that are consumed when the body is at rest, however, are stored. Relatively small amounts of carbohydrates can be stored in the muscles and the liver as a complex sugar called glycogen. When glycogen stores are full, however, and there is no further demand for sugar, carbohydrates are stored as fat.

Although most doctors and nutritionists still recommend that people get the majority of their calories from carbohydrates, they also suggest that many people would benefit from increasing their fat intake. According to most nutritionists, the ratio of carbohydrate, fat, and protein calories should, in fact, be much closer to equal -- at 40, 30, and 30 percent respectively. They stress that exercising and eating moderately from all of the food groups is the proper path to better health.

Questions for Discussion

  • Could you stay healthy eating three or fewer of the foods shown here? Explain your answer, using information from the site.
  • Why do you think 75 percent of the U.S. population doesn't meet daily recommended dietary needs? What ideas do you have about changing the nutritional habits of people in this country?
SOURCE: http://www.pbs.org/wgbh/nova/education/body/body-needs.html?elq=0937217e29c949998c57be7bcd65db11&elqCampaignId=431

DNA - Nova

NOVA
 VIEW


DNA. It's what makes you unique. Unless you have an identical twin, your DNA is different from that of every other person in the world. And that’s what makes DNA fingerprinting possible. Experts can use DNA fingerprints for everything from determining a biological mother or father to identifying the suspect of a crime. What, then, is a DNA fingerprint and how is it made? Here, you'll find out by solving a mystery—a crime of sorts. First, you’ll create a DNA fingerprint (we'll supply the lab and all necessary materials). Then you’ll compare this DNA fingerprint to those of all seven suspects to nab the perpetrator. Ready? Let's get to work!

VIEW
  • Media Type: Interactive
  • Size: 283.0 KB
  • Level: Grades 6-12
  • Log in to Teachers' Domain to download, share, rate, save, and match to state standards.
Source: NOVA: "The Killer's Trail" Web site
This feature originally appeared, in a different design, on the site for the NOVA program .

Background

In the last 15 years, DNA has played an increasingly important role in our legal system. Tissue evidence is now routinely collected during criminal investigations in hopes that it will provide genetic clues linking suspected criminals to crimes.

DNA profiles help forensic investigators determine whether two tissue samples -- one from the crime scene and one from a suspect -- came from the same individual. Fortunately, the genetic comparison doesn't require that investigators look at all of the DNA found in the tissue samples. That would take months or even years. Instead, by marking a small number of segments of DNA in one sample and then checking for the presence or absence of those segments in the other sample, investigators can say with some assurance whether the samples are from the same person.

How do they do it? Investigators use chemicals to cut the long strands of DNA into much smaller segments. Each segment has a specific length, but all of them share the same repeating sequence of bases (or nucleotides). The chemicals cut the segments at the beginning and at the end of the repeating string of nucleotides, so one segment might be ATCATCATCATCATC, for example, while another might be ATCATC. (The DNA segments used in forensic investigations are, of course, much longer than this.)

Investigators use a process called gel electrophoresis to separate these repeating segments according to length. Next, they introduce a small set of radioactive "markers" to the sample. These markers are segments of DNA of known length, with bases that complement the code of, and bind to, sample segments of the same length. The sample segment above (ATCATCATCATCATC), for example, would be tagged by a marker with the complementary code TAGTAGTAGTAGTAG.

Markers that do not bind to sample segments are then rinsed away, leaving in place only those markers that bound to complementary sample segments. Photographic film, which darkens when exposed to the radioactive markers, identifies the location of all marked sample segments. This film, then, becomes the DNA "fingerprint" that forensic investigators analyze.

The final step is a relatively simple matter of lining up the sample profiles side by side and comparing them for the presence or absence of segments with particular lengths. The more segments the two samples have in common, the more likely it is that the samples came from the same person.

Questions for Discussion

  • Describe the process of DNA fingerprinting.
  • In what ways is it like actual fingerprinting and in what ways is it different?
  • How conclusive is the evidence of DNA fingerprinting?
  • Where is there possibility for error?

SOURCE: http://www.pbs.org/wgbh/nova/education/body/create-dna-fingerprint.html?elq=0937217e29c949998c57be7bcd65db11&elqCampaignId=431

Wednesday, August 31, 2011

Engineering Ground Zero (NOVA)

Building Green
The new season of NOVA kicks off with Engineering Ground Zero. This month, SPARK explores green energy as it relates to sustainable building. From defining alternative energy to understanding the influence of Mother Nature in building construction, these resources shed light on the direction and future of building innovation.
Join us on Facebook and Twitter, or visit the NOVA Teachers and Teachers' Domain websites to tap a wealth of great STEM-related video clips, animations, interactives, and activities.


Keep investigating!
Rachel Connolly, Director of Education, NOVA
future_cities
Designing Future Cities: Alternative Energy
Can you design the green city of the future? 
Take on the role of city planner and work out design solutions that incorporate innovative energy alternatives.
Video (2m 11s), Grades 3-8
stone_arches
Physics of Stone Arches  
How do arches stay standing? 
Try your hand at constructing a cathedral arch and learn more about the physics behind the arch.
Interactive, Grades 7-12
green_technology
Green Technology: Sustaining the Earth
How can technology move us toward a greener future?
Explore areas of research and innovation in green technology: renewable energy and conservation; green building; transportation; manufacturing; and pollution and waste management. 
Interactive, Grades 6-12
structureofmetal.jpg
The Structure of MetalWhat makes metal special?
Explore metal at the atomic level and find out what makes it such a versatile material.
Interactive, Grades 6-12
super_materials
Nature's Super Materials
How is Mother Nature inspiring the next generation of strong materials?
See some of the amazing structures and properties that animals and plants have evolved, and learn about new human-made super-materials they are giving rise to.
Interactive, Grades 6-12

It's Elemental (with example worksheet)

Whether they are created by nature or in the lab, chemical substances are all made of some combination of just 118 pure elements.

These elements come together to produce an amazing diversity of materials. In this interactive, discover which elements are most abundant in the universe, the sun, and the Earth as well as in the human body and in that flashiest of human creations—fireworks.

Also, learn which elements have the most extreme properties on the periodic table.
 
 
  In this interactive periodic table, explore the elements and their properties and abundances.

A previous version of this feature originally appeared on the site for the NOVA program Kaboom!.




EXAMPLE WORKSHEET (with answers)

Elements of the SUN

 Pablo Cortez  IHM

8-31-11 Wednesday

1st most abundant element of the SUN: Hydrogen
Symbol: H
Family: Alkali metals

2nd most abundant element of the SUN: Helium
Symbol: He
Family: Noble gasses

3rd most abundant element of the SUN: Oxygen
Symbol: O
Family: Nonmetals

4th most abundant element of the SUN: Carbon
Symbol: C
Family: Nonmetals

5th most abundant element of the SUN:  Nitrogen
Symbol: N
Family: Nonmetals

6th most abundant element of the SUN: Neon
Symbol: Ne
Family: Noble gasses

7th most abundant element of the SUN: Iron
Symbol: Fe
Family: Transition metals

8th most abundant element of the SUN: Silicon
Symbol: Si
Family: Nonmetals

9th most abundant element of the SUN: Magnesium
Symbol:  Mg
Family: Alkaline earth metals

10th most abundant element of the SUN: Sulfer
Symbol: S
Family: Nonmetals

 

Sources:

NOVA:  http://www.pbs.org/wgbh/nova/physics/periodic-table.html 

Data provided by PeriodicTable.com. Melting point, boiling point, and density data apply to elements at standard atmospheric pressure. 
 

 

Physics of the Stone Arches (NOVA interactive)


Arches

Medieval architects were masters at building with stone. But as cathedral design evolved, some medieval architects began to push beyond the boundaries of known structural design and into unknown territory.

With the pursuit of taller and taller cathedrals, any errors could lead to catastrophic collapses. In this interactive, try your hand (safely) at constructing a cathedral arch and learn more about the physics behind the arch.

  See if you can build a cathedral arch without it collapsing, and learn more about the forces at work.

Editor's Note: The arch diagrams and thrust lines are simplified for illustrative purposes. Our interactive arch exists in a virtual world that does not completely reflect real-world physics.

Wednesday, June 1, 2011

NOVA Spave Videos


spacesuits
Next-Generation Space Suits
How have giraffes inspired revolutionary changes in space suit design?
Today's suits are notoriously bulky. MIT's Dava Newman is out to change that with a radical, and sleek, new design.

Video (10m 45s), Grades 6-12
spacefood
Space Food  
How do you keep food fresh on a three-year round-trip to Mars? 
NASA scientist-chefs are devising new ways to keep space food tasting fresh and healthy.
Video (6m 51s), Grades 6-12
plasmarocket
Plasma Rockets
Why does it take so long to get to Mars and how can we speed up the trip?
With a "small sun” for an engine, a new rocket might be able to zip us to Mars and back in under three months.
Video (6m 38s), Grades 6-12
spacetools
How Would You Turn a Bolt in Space?How does gravity help a person on Earth who is using a power drill?
Watch and astronaut explain the challenges of using of tools in space.
Video (0m 47s), Grades 3-8
zoomweightlessness
What is "Weightlessness?"
How can you experience "weightlessness" on Earth?
See how dropping a cup of water can create a condition of "weightlessness."

Video (1m 17s), Grades K-8