Serving sizes on food labels are designed to make it easier to compare the calorie and nutritional content of similar products and to identify nutrients present in a food. At a minimum, food labels contain information about serving sizes; calories; calories from fat (dietitians generally recommend that no more than 30% of calories come from fat over the course of the day); percent daily values of major nutrients; total fat; saturated and trans fat (these unhealthy fats are listed under total fat—saturated fat and trans fat raise cholesterol and increase a person's risk for developing heart disease); unsaturated fats (liquid at room temperature, these are the healthy fats); cholesterol; sodium; total carbohydrates (which includes dietary fibers, sugars, and other carbohydrates); protein; vitamins A and C; calcium and iron.

Carbohydrates are the most abundant source of calories in most people’s diets. Carbohydrates are either simple (called sugars) or complex (called starches). Cereals, rice, potatoes, breads, pastas, fruits, and vegetables all contain high amounts of carbohydrates. Not all sugar in food is added. Lactose, or milk sugar, is a natural ingredient in milk. Fruit also has high amounts of naturally occurring sugar.

When reading a food label, it is important to pay attention to the number of servings contained within a package and the amount of saturated fat. Saturated fat contributes to heart disease—the number one killer of adults in the US. Most saturated fats are solid at room temperature. The words, "hydrogenated," "partially hydrogenated," or "shortening,” also are used to describe saturated fats.  With true “low-fat” foods, fewer than 30%  of the total calories come from fat.

Water is by far the most commonly used solvent in biology because it is the major component of all living organisms. Most known biochemical reactions take place in an aqueous environment, and water is frequently a reactant in, or a product of, biochemical reactions. Biologically important macromolecules, organelles, cells, and organs all are designed to function in an aqueous environment.

Water quality is highly variable, and for any task an appropriate grade of water must be chosen. For example, tap water is fine for washing dishes, but it is not recommended for making solutions because the quality of such water is unknown. Tap water typically contains sediments (suspended particles), metal and other ions, deliberately added chemicals such as chlorine or fluoride, and/or traces of organic solvents. Although tap water is generally safe for drinking and other personal uses, materials in tap water can be toxic to some cells or may interfere with assays or biochemical reactions. Therefore, tap water is inappropriate for making solutions. Also, it is recommended that glassware that has been washed and rinsed in tap water be thoroughly rinsed with a higher quality water before use in the laboratory.

Distilled water, obtained from the condensation of steam, is of better quality because distillation eliminates all the sediment and most of the inorganic solutes. Organic contaminants and some of the inorganic contaminants remain.

Deionized water is produced by running tap water through a resin cartridge, or series of cartridges. A home deionizing system might simply replace divalent cations with sodium ions, producing what is commonly known as "soft" water. Laboratory deionized water is usually treated to remove both cations and anions, which are exchanged for hydrogen and hydroxyl ions, respectively. Deionized water often is of better quality than distilled water. However, on the downside, the resins used in the cartridges may release organic contaminants into the water.

The highest grade of water is called 18 megohm water. Eighteen megohms is 18 million ohms, which are units representing resistance to the flow of electricity. Eighteen meghoms is more than a million times the electrical resistance of a typical household electric circuit. Very pure water does not conduct electricity as well as contaminated water because it contains no inorganic ions with which to carry electric current. Eighteen megohm water is usually produced in multiple steps, including reverse osmosis and the passage of product through ion exchange resins, activated carbon beds and filters.

Pure water is somewhat acidic, with pH close to 5. It is also what we call an aggressive reagent, meaning that it will leech ions from plastic or glass containers. It does so because of the polar nature of water molecules. Ions dissolve most readily in 18 megohm water because the system (water plus dissolved ions) is more stable than when pure water is separated from soluble materials. Because very pure water accumulates contaminants during storage, it should be freshly prepared. Avoid use of plastic tubing, funnels, and especially metal containers.

 

Four issues will be discussed in this presentation. First, we will address the importance of nutrition to manned spaceflight. Next, we will focus on two key areas of concern that can be impacted positively by nutritional countermeasures: muscle wasting and radiation-enhanced cancer. When nutrients are consumed they affect the entire body, not just one physiological system. So we must consider the effect of any nutritional or exercise countermeasure on the whole person. That topic will be emphasized in section three of this presentation. Finally, we will see how countermeasures developed for use in space apply equally well to health challenges here on earth.

The amount of energy stored in food usually is measured in calories. One calorie is defined as the amount of energy needed to raise the temperature of one gram of pure water (equivalent to one milliliter of water) one degree Celsius. The calories shown on most food labels actually are kilocalories (=1,000 calories). The word “Calorie,” when written with an upper case “C,” also denotes kilocalories.

When a carbon-containing molecule is burned (combustion), it consumes oxygen, produces carbon dioxide and water, and liberates energy (which can be felt as heat).

Since this activity involves an open flame, teachers may prefer to conduct it as a demonstration for the class. If students are performing the investigation in groups, the following safety guidelines from the Council of State Science Supervisors should be followed.

1. Demonstrate the procedure before allowing students to replicate the activity. Look for possible hazards in the classroom. Alert students to potential dangers.

2. Constant surveillance and supervision of student activities are essential.

3. Smoke, carbon monoxide, and heat detectors are recommended in every laboratory. Units should be placed in the laboratory and related areas (storerooms, preparation rooms, closets, and offices).

4. A positive student attitude toward safety is imperative. Students should not fear doing experiments, using reagents, or equipment, but should respect them for potential hazards. Students should read lab materials in advance, noting all cautions (written and oral).

5. Teachers must set good safety examples when conducting demonstrations and experiments. They should model good lab safety techniques, such as wearing aprons and goggles.

6. Rough play or mischief should not be permitted in science classrooms or labs.

7. Closed-toe shoes are required for labs involving liquids, or heated or heavy items that may injure the feet.

8. Confine long hair and loose clothing. Laboratory aprons should be worn.

9. Proper eye protection devices must be worn by all persons engaged in supervising or observing science activities involving potential hazards to the eye.

10. Give consideration to the National Science Teachers Association's recommendation to limit science classes to 24 students or less for safety.

The complete Food and Fitness Activities Guide for Teachers may be downloaded as a PDF file from the Teacher Resources menu on BioEd Online: http://www.bioedonline.org/resources/nsbri.cfm

Influenza, commonly known as flu, is a contagious disease caused by the influenza type A, B, and C viruses. Type A, the most common and severe form in humans, also infects other animals, such as ducks, chickens, pigs, whales, horses, and seals. Type B circulates only among humans. Type C is believed to cause only mild respiratory illness and never has been associated with a large epidemic. Influenza type A is believed to be responsible for global flu outbreaks in 1918, 1957 and 1968.

In humans, influenza virus attacks the respiratory tract (nose, throat and lungs). Most people who contract influenza recover within a couple of weeks. However, life threatening conditions develop in some people. Annually, approximately 200,000 persons are hospitalized in the US due to flu (Thompson, et al., 2004; CDC, 2004). In addition, flu causes an average of 36,000 deaths per year.  As reported by Thompson, et al. (2004), people 85 years or older had the highest rates of influenza-associated respiratory and circulatory hospitalizations over the past ten years. Children under the age of five had hospitalization rates similar to those of adults aged 50-64 years. Other groups at risk include pregnant women and persons with underlying health conditions.

Like all viruses, influenza viruses consist of genetic material surrounded by a protective coat. Viruses reproduce by entering a living host cell and hijacking the cell's machinery to manufacture new viruses. Flu viruses evolve very rapidly. Their genetic material consists of segments of single-stranded RNA that can be shuffled and exchanged whenever multiple viruses infect a single cell. In addition, flu virus RNA mutates at a very high rate (Smolinski, et al., 2003).

Human influenza viruses are divided into two main groups, type A and type B. Type A viruses are found in ducks, chickens, pigs, whales, and humans, among other animals. Type B viruses are known to circulate only among humans. An additional form of the virus, Type C influenza, has been identified in humans, pigs and dogs, but has not yet caused serious disease or epidemics in humans.

Influenza Type B viruses are not divided into subgroups, but A viruses are categorized into subtypes based on two important proteins present on the surface of the virus. In general, influenza type A virus is round (although it can be elongated or irregularly shaped). It is surrounded by a protein layer and a two-layered lipid envelope from which different kinds of protein spikes protrude. Two of these proteins-hemagglutinin (H), a protein that helps the virus attach to host cells in the respiratory tract) and neuraminidase (N), which releases the newly created influenza virus from host cells-are variable. Types of Influenza A virus are based on variations in the hemagglutinin (H), of which there are 15 subgroups, and neuraminidase (N), of which there are 9 subgroups. Most of these subgroups are found only in bird populations. At this time, only three of the 15 H subtypes have infected humans. Currently, subtypes H1N1 and H3N2 are the active forms of human Type A influenza virus. The H3N2 subtype was responsible for the epidemic of "Hong-Kong" flu in 1968. The outbreak of "Bird" flu in Hong Kong was attributed to H5N1, however, this subtype was not shown to be transmissible form person to person (only from birds to humans).

Immunity is based on the body's ability to identify the viral surface proteins, hemagglutinin and neuraminidase. Antibodies produced by the immune system that fight one type or subtype of influenza confer very limited or no protection against other types. Since the viruses mutate rapidly, vaccines must be reformulated from year to year to be effective.

Flu spreads through the air, in droplets and small particles emitted when infected individuals cough or sneeze. Flu also can be spread when someone touches respiratory droplets on another person or an object and then touches his or her own mouth or nose. Symptoms include high fever (102-104°F), headache, sore throat, non-productive and dry cough, muscle aches, some gastrointestinal problems, and extreme tiredness.

A person can spread the flu one day before he or she feels any symptoms, and remains contagious for three to seven days after symptoms begin.

Most people recover from flu within one to two weeks. However, others may develop life threatening complications, such as bacterial pneumonia, dehydration, and worsening of chronic medical conditions.

The influenza vaccine is the single best preventative measure. Currently there are two types of vaccines available. The "flu shot" contains an inactivated virus and usually is administered to people older than 6 months. About 55 million flu shots will be available in the United States this season. The second vaccine is a nasal spray made with live but weakened flu viruses. This vaccine is approved for healthy people aged 5 to 49, not including pregnant woman. Vaccinations are not recommended for individuals who are allergic to chicken eggs, have had a severe reaction to an influenza vaccination in the past, have developed Guillain-Barre syndrome within six weeks of a previous vaccination, are less than six months of age, or have a fever.

Because of a shortfall in flu vaccine production this season, the Centers for Disease Control and Prevention (CDC) is recommending that certain people be given priority for getting a flu shot. People in the following groups should seek vaccination this season: all children aged 6-23 months; adults aged 65 years and older;   persons aged 2-64 years with underlying chronic medical conditions; all women who will be pregnant during the influenza season;  residents of nursing homes and long-term care facilities; children aged 6 months-18 years on chronic aspirin therapy; health-care workers involved in direct patient care; and  out-of-home caregivers and household contacts of children aged <6 months. These are people who are at high risk for serious flu complications or are in contact with people at high risk for serious flu complications.

The CDC requests that people who are not included in one of the priority groups forego or defer vaccination because of the vaccine supply situation. This means that preventive measures-covering one's mouth when coughing or sneezing, staying home if infected with flu, avoiding touching of the mouth and nose, and washing hands frequently-will be even more important this flu season.

Due to genetic changes in the virus, flu vaccines are adjusted each year. Changes are based on international surveillance of the virus and scientists' predictions about which types viruses will be circulating during the coming year. The vaccination begins to take effect about two weeks after administration, because it takes the body this long to develop antibodies against the influenza virus.

Many primary and secondary schools have web sites where you can learn more about the topics introduced on the previous slide. In addition to a school’s website, be sure to visit the school district web site to learn more about the district’s goals, core values, and leadership. Some teachers also have their own websites. If you know the names of teachers at the school, it can be helpful to review their sites as well.

The U.S. Department of Education hosts a site that may help you to locate individual state education agencies. To find detailed information on a Texas school’s performance, visit the Texas Education Agency’s web site. Here, you will find information about a school’s student demographics, performance on theTexas Assessment of Knowledge and Skills (TAKS), standardized test scores on the SAT/ACT, graduation and dropout rates, staff, programs, and financial standing. This site provides access to information about a school’s performance over multiple years, which may reveal upward or downward trends in specific areas.

Other resources for data on schools include the following:
National Center for Education Statistics: http//nces.ed.gov/
National Education Association http://www.nea.org/index.html
Council of Chief State School Officers http://www.ccsso.org/

In addition to these resources, consult with your educational advisors, or other teachers/administrators you may know, prior to an interview. They may be able to provide additional “inside” information about a school’s leadership, culture, and challenges–information that is not widely publicized. Remember, however, that unless a person’s opinion is confirmed by other sources, it is the opinion of only one person and may not be widely held. Finally, it never can hurt to call a school directly to speak with administrators or teachers about specific issues that may help you to prepare for your interview.

Before you interview, develop a concise, informative description of your background, teaching-related interests, and reasons for wanting to teach. These central issues are certain to be part of your interview, and it will be important to have solid responses immediately at hand when needed.

Also, reflect on your personal strengths and weaknesses as they relate to the job. It is important to be honest with yourself and with your interviewer(s), and to demonstrate realistic awareness of both your strong points and areas in which you need to improve. For example, you may have considerable knowledge of biology based on your undergraduate education and experience as a laboratory technician, but you may not have much teaching experience. You may have a lot of energy and enthusiasm, but those strengths may get taxed to the limit because you have a hard time saying “no” when someone asks you to do something. You may communicate well in small groups and in one-on-one situations, but struggle to present material in front of larger groups.

Think of specific, concrete examples of how your strengths have enabled you to accomplish your goals in the past, and how you are addressing/will address any perceived weaknesses. Be prepared to discuss these issues. Let’s say you’re excited about teaching but don’t have much experience. You might acknowledge that you do not have first-hand experience managing a classroom, but you have interacted with children, and you have realistic expectations of what it will be like when you are given the opportunity to teach. Then you need to provide as much evidence as possible to support your claim.

Think carefully about how to make the most of whatever teaching-related experiences you have had. Be prepared to discuss any past experiences, especially those that involved children(e.g., private tutoring, coaching, leading a troop of Boy/Girl Scouts, Sunday school, training new employees in your department, etc.). In addition, describe any classroom observations that you completed as part of your teacher training and how those have shaped your own teaching philosophy and classroom management style. Be sure to explain how your educational background has prepared you for the classroom. You may even want to mention influential teachers who have shaped your vision of yourself as an educator.