12 Food Additives to Avoid

Including something new in a food isn’t always a good idea, especially when it comes to your health. Here are 12 additives to subtract from your diet:

1. Sodium Nitrate (also called Sodium Nitrite)

This is a preservative, coloring, and flavoring commonly added to bacon, ham, hot dogs, luncheon meats, smoked fish, and corned beef. Studies have linked eating it to various types of cancer.

2. BHA and BHT

Butylated hydroxyanisole and butylated hydrozyttoluene are used to preserve common household foods. They are found in cereals, chewing gum, potato chips, and vegetable oils. They are oxidants, which form potentially cancer-causing reactive compounds in your body.

3. Propyl Gallate

Another preservative, often used in conjunction with BHA and BHT. It is sometimes found in meat products, chicken soup base, and chewing gum. Animals studies have suggested that it could be linked to cancer.

4. Monosodium Glutamate (MSG)

MSG is an amino acid used as a flavor enhancer in soups, salad dressings, chips, frozen entrees, and restaurant food. It can cause headaches and nausea, and animal studies link it to damaged nerve cells in the brains of infant mice.

5. Trans Fats

Trans fats are proven to cause heart disease. Restaurant food, especially fast food chains, often serve foods laden with trans fats.

6. Aspartame

Aspartame, also known by the brand names Nutrasweet and Equal, is a sweetener found in so-called diet foods such as low-calorie desserts, gelatins, drink mixes, and soft drinks. It may cause cancer or neurological problems, such as dizziness or hallucinations.

7. Acesulfame-K

This is a relatively new artificial sweetener found in baked goods, chewing gum, and gelatin desserts. There is a general concern that testing on this product has been scant, and some studies show the additive may cause cancer in rats.

8. Food Colorings: Blue 1, 2; Red 3; Green 3; Yellow 6

Five food colorings still on the market are linked with cancer in animal testing. Blue 1 and 2, found in beverages, candy, baked goods and pet food, have been linked to cancer in mice. Red 3, used to dye cherries, fruit cocktail, candy, and baked goods, has been shown to cause thyroid tumors in rats. Green 3, added to candy and beverages, has been linked to bladder cancer. The widely used yellow 6, added to beverages, sausage, gelatin, baked goods, and candy, has been linked to tumors of the adrenal gland and kidney.

9. Olestra

Olestra, a synthetic fat found in some potato chip brands, can cause severe diarrhea, abdominal cramps, and gas. Olestra also inhibits healthy vitamin absorption from fat-soluble carotenoids that are found in fruits and vegetables.

10. Potassium Bromate

Potassium bromate is used as an additive to increase volume in some white flour, breads, and rolls. It is known to cause cancer in animals, and even small amounts in bread can create a risk for humans.

11. White Sugar

Watch out for foods with added sugars, such as baked goods, cereals, crackers, sauces and many other processed foods. It is unsafe for your health, and promotes bad nutrition.

12. Sodium Chloride

A dash of sodium chloride, more commonly known as salt, can bring flavor to your meal. But too much salt can be dangerous for your health, leading to high blood pressure, heart attack, stroke, and kidney failure.

Article source:http://articles.mercola.com/sites/articles/archive/2008/06/24/12-food-additives-to-avoid.aspx

Telescope

A telescope is perhaps the most important astronomical tool; such technology gathers (and focuses) electromagnetic radiation. Telescopes increase the apparent angular size of objects, as well as their apparent brightness. Galileo is credited with being the first to use a telescope for astronomical purposes. Telescopes used for non-astronomical purposes are often referred to as transits, spotting scopes, monoculars, binoculars, camera lenses, or spyglasses.

The word "telescope" usually refers to optical telescopes, but there are telescopes for most of the spectrum of electromagnetic radiation.

Radio telescopes are focused radio antennas, usually shaped like large dishes. The dish is sometimes constructed of a conductive wire mesh whose openings are smaller than a wavelength. Radio telescopes are often operated in pairs, or larger groups to synthesize large "virtual" apertures that are similar in size to the separation between the telescopes: see aperture synthesis. The current record is nearly the width of the Earth. Aperture synthesis is now also being applied to optical telescopes.

X-ray and gamma-ray telescopes have a problem because the rays go through most metals and glasses. They use ring-shaped "glancing" mirrors made of heavy metals, that reflect the rays just a few degrees. The mirrors are usually a section of a rotated parabola.

Telescope mountings

The simpliest telescope mounting is an altazimuth mount. It is similar to that of a surveying transit. A fork rotates in azimuth, and bearings on the tips of the fork allow the telescope to vary in altitude.

The major problem with using an altazimuth for astronomy is that both axes must be continuously adjusted to compensate for the Earth's rotation. Even if this is done, by computer control, the image rotates at a rate that varies depending on the angle of the star from the celestial pole. The last effect especially makes an altazimuth mount impractical for long-exposure photography with small telescopes.

The preferred solution for many small telescopes is to tip the altazimuth so that the azimuth axis is parallel with the axis of the Earth's rotation, this is known as equatorial mount.

Very large telescopes typically use a computer-controlled altazimuth mount, and for long exposures, they have (usually computer-controlled) variable-rate rotating erector prisms at the focus.

Research Telescopes

Most large research telescopes can operate as either a cassegrainian (longer focal length, and a narrower field with higher magnification) or newtonian (brighter field). They have a pierced primary, a newtonian focus, and a spider to mount a variety of replaceable secondaries.

A new era of telescope making was inaugurated by the MMT, a synthetic aperture composed of six segments synthesizing a mirror of 4.5 meters diameter. Its example was followed by the Keck telescopes, a synthetic-aperture 10 meter telescope.

The current generation of telescopes being constructed have a primary mirror of between 6 and 8 meters in diameter (for ground-based telescopes). In this generation of telescopes, the mirror is usually very thin, and is kept in an optimal shape by an array of actuators (see active optics). This technology has driven new designs for future telescopes with diameters of 30, 50 and even 100 meters.

Initially the detector used in telescopes was the human eye. Later, the sensitized photographic plate took its place, and the spectrograph was introduced, allowing the gathering of spectral information. After the photographic plate, successive generations of electronic detectors, such as CCDs, have been perfected, each with more sensitivity and resolution.

Current research telescopes have several instruments to choose from: imagers, of different spectral responses; spectrographs, useful in different regions of the spectrum; polarimeters, that detect light polarization, etc.

In recent years, some technologies to overcome the bad effect of atmosphere on ground-based telescopes were developed, with good results. See tip-tilt mirror and adaptive optics.

The phenomenon of optical diffraction sets a limit to the resolution and image quality that a telescope can achieve, which is the effective area of the Airy disc, which limits how close we may place two such discs. This absolute limit is called Sparrow's resolution limit. This limit depends on the wavelength of the studied light (so that the limit for red light comes much earlier than the limit for blue light) and on the diameter of the telescope mirror. This means that a telescope with a certain mirror diameter can resolve up to a certain limit at a certain wavelength, so if you want more resolution at that very wavelength, you have to build a wider mirror.

Famous Telescopes

• The Hubble space telescope is in orbit outside of the Earth's atmosphere to allow for observations not distorted by refraction, in this way they can be diffraction limited, and used for coverage in the ultraviolet (UV) and infrared.
• The Very Large Telescope (VLT) is currently (2002) the record holder in size, with four telescopes each 8 meters in diameter. The four telescopes, belonging to ESO and located in the Atacama desert in Chile, can operate independently or together.
• There are many plans for even larger telescopes, one of them is the Overwhelmingly Large Telescope or OWL, which is intended to have a single aperture of 100 meters in diameter.
• The 200 inch Hale telescope at Mt. Palomar is a conventional research telescope that was the largest for many years. It has a single borosilicate (Pyrex (TM)) mirror that was famously difficult to construct. The mounting is also unique, an equatorial mount that is not a fork, yet permits the telescope to image near the north celestial pole.
• The 100 inch Mt. Wilson telescope was used by Edwin Hubble to discover galaxies, and the redshift. It is now part of a synthetic aperture array with several other Mt. Wilson telescopes, and is still useful for advanced research.
• The 0.91m Yerkes Telescope (in Wisconsin) is the largest aimable refractor in use.
• The largest refractor ever constructed was French. It was on display at the 1900 Paris Exposition. Its lens was stationary, prefigured so as to sag into the correct shape. The telescope was aimed by by the aid of a Foucault sid�rostat, which is a movable plane mirror of diameter 6.56 feet, mounted in a large cast-iron frame. The horizontal tube was 197 feet long and the objective had 4.1 feet in diameter. It was a failure.

Article source:http://www.encyclopedia4u.com/t/telescope-1.html

Five Smart Strategies to Lower Your Blood Pressure Naturally

What is High Blood Pressure?

You are generally diagnosed with pre-hypertension if your blood pressure is between 120/80 and 140/80, and anything above 140/80 is generally diagnosed as hypertension.

The first number is your systolic pressure, which should typically be below 120. The second number is your diastolic pressure, which should typically be below 80. If either your systolic or diastolic number is higher than the typical 120/80, you may get a diagnosis of hypertension, or pre-hypertension.

If you’ve been diagnosed with high blood pressure, you should know that a common risk factor for high blood pressure is weight. So if you’re obese that is going to increase your risk for developing high blood pressure.

However, it’s important to realize that your blood pressure reading may be inaccurate if you’re getting your pressure measured with an ill-fitting blood pressure cuff. Your blood pressure is measured by placing a cuff around your arm, and these cuffs are available in different sizes. So, if you are large, you will require a larger cuff in order to get an accurate reading. Likewise, a child’s blood pressure should be measured using a pediatric cuff.

What Causes High Blood Pressure?

For the most part, high blood pressure is related to your body producing too much insulin. As your insulin levels rise, it causes your blood pressure to increase. Research published in 1998 in the journal Diabetes reported that nearly two-thirds of the test subjects who were insulin resistant also had high blood pressure.

This crucial connection between insulin resistance and hypertension is yet another example of how wide-ranging the debilitating effects of high insulin, leptin and blood glucose levels can have on your body.

I highly recommend you get a fasting insulin level test done by your doctor. The level you want to strive for is about 2 or 3. If it’s 5, or over 10, you have a problem and you definitely need to lower your insulin levels to lower your risk of high blood pressure and other cardiovascular problems.

Fortunately, there are a few very simple techniques that will lower your insulin levels. And if your hypertension is the direct result of an out-of-control blood sugar level, then normalizing your blood sugar levels will also bring your blood pressure readings into the healthy range.

How to Effectively Treat High Blood Pressure Without Drugs

A vast majority of people can normalize their blood pressure by implementing a few simple techniques that address the underlying cause, namely high insulin levels.

Exercise – One of the most effective ways to lower your insulin levels is through exercise. A regular, effective exercise program consisting of aerobics, sprint-burst type exercises, and strength training, can go a long way toward reducing your insulin levels and your blood pressure.

Ideally, you’ll want someone to supervise your program and monitor your progress. To reap the optimal effects from your exercise program, you’ll need about an hour a day. Just remember to start slowly and work your way up to that level.

Avoid foods that boost insulin levels – Another effective method is to avoid foods that will raise your insulin, such as sugar-type foods and grains. Even whole, organic grains will rapidly break down to sugars, so they too should be avoided.

If you have high blood pressure, high cholesterol, or obesity, you’ll want to avoid foods like:

• Breads
• Pasta
• Rice
• Cereal
• Potatoes

While vitamin C may be helpful, you'll also want to avoid eating too many fruits; the types and amounts being adjusted based on your nutritional type.

One food that can be helpful for reducing your blood pressure is crushed, raw garlic. Many people swear by it, and it's something you can easily add to your diet.

Reduce your stress – You’ll also want to take steps to reduce your stress, as that is a factor for some people. Prayer, meditation, or the Emotional Freedom Technique are all useful techniques.

Normalize your vitamin D levels – It has recently become clear that normalizing your vitamin D levels can have a powerful effect on normalizing your blood pressure. Lower Vitamin D levels is also unquestionably associated with an increased risk for heart disease.

Additionally, previous research has revealed that if your blood pressure doesn’t drop notably overnight, you run an increased risk of having cardiovascular problems. Here, the connection is also elevated blood sugar (glucose) levels as elevated blood sugars can result in diabetes and other diseases which increase cardiovascular problems.

And likewise, vitamin D has been shown to have a positive impact on diabetes, so it’s all linked together.

Balance your omega-6 to omega-3 fat ratio – Most Americans eating a standard American diet have a ratio of 25:1, which is highly unbalanced. The ideal ratio of omega-6 to omega-3 fats is 1:1. Therefore, you’ll want to lower the amount of vegetable oils in your diet, and make sure you have a high quality, animal-based source of omega-3s.

A Warning if You have Very High Blood Pressure, or are Currently on Medication for Hypertension

As most of you already know, I’m opposed to taking medications and drugs, and clearly the long term goal is to get off all your medications. However, if you are on a medication, you certainly want to wean yourself off it under the guidance of a healthcare professional.

Additionally, although I hardly ever recommend the use of drugs, it’s VITAL that you do go on a medication to lower your blood pressure if your blood pressure is very high! Otherwise you are putting yourself at serious risk of a stroke, and the brain damage that occurs during a stroke tends to be permanent and irreversible.

Article source :http://articles.mercola.com/sites/articles/archive/2009/02/03/five-smart-strategies-to-lower-your-blood-pressure-naturally.aspx

star formation

Star formation is the process by which gas in molecular clouds gets transformed into stars.

In the current paradigm of star formation, cores of molecular clouds (regions of especially high density) become gravitationally unstable, and start to collapse. Part of the gravitational energy lost in this collapse is radiated in the infrared, with the remainder increasing the temperature of the core. The accretion of material happens partially though a circumstellar disc. When the density and temperature are high enough, deuterium ignites, undergoing fusion, and the outward pressure of the resultant radiation slows (but does not stop) the collapse. After it is exhausted, material from the cloud continues to "rain" onto the protostar. In this stage bipolar flows are produced, probably to eliminate part of the angular momentum of the falling material. Finally, hydrogen ignites in the core of the star, and the rest of the enveloping material is cleared away.

The stages of the process are well defined stars with masses around one solar mass or less. In high mass stars, the length of the star formation process is comparable to the other timescales of their evolution and the process is not so well defined. The later evolution of stars are studied in stellar evolution.

Observations

Key elements of star formation are only available by observing in wavelengths other than the optical. The structure of the molecular cloud and the effects of the protostar are best observed in rotational transitions of CO and other molecules; these are observed in the millimeter and submillimeter range. The radiation from the protostar and early star has to be observed in infrared astronomy wavelengths, the extinction caused by the rest of the cloud where it is being formed is usually too big to allow us to observe it in the visual part of the spectrum.

The formation of individual stars, can only be directly observed in our Galaxy, but in distant galaxies star formation has been detected through its unique spectral signature.

Article source :http://www.encyclopedia4u.com/s/star-formation-1.html

weather tools

Article source:www.nebo.edu/misc/learning_resources/ppt/k-5/weathertrools.ppt

Plant pigments

What is a plant pigment ?

In biology, a pigment is any material resulting in color of plant or animal cells.

Among the most important molecules for plant function are the pigments .

Plant pigments include a variety of different kinds of molecules.

All biological pigments selectively absorb certain wavelengths of light while reflecting others. the light that is absorbed may be used by the plant to power chemical reactions , while the reflected wavelengths of light determine the color the pigment will appear to the eye. Pigments also play important role in plant metabolism and attracting pollinators

Classification of plant pigments

Plant pigments are classified according to its location in the plant cell into two types:

1- pigments of cell sap

2- pigments of plastids

Pigments of cell sap (vacuole)

The cell vacuole:

a large, membrane-bound space within a plant cell that is filled with fluid. Most plant cells have a single vacuole that takes up much of the cell. It helps maintain the shape of the cell.

The vacuole contains pigments dissolving in water and these pigments are responsible for the color of fruits and the flower petals.

They have no relations with the metabolism.

These pigments can act as pH indicators and they can be extracted by using a diluted acidic medium.

Examples of these pigments are anthocyanin and tannins.

Anthocyanins

It may appear red, purple or blue according to the pH.

Anthocyanins belong to a parent class of molecules called flavonoids

Anthocyanins occur in all tissues of higher plants specially in flowers and fruits.

About 100 different anthocyanins are known

In flowers, bright reds and purples are adaptive for attracting pollinators. In fruits, the colorful skins also attract the attention of animals, which may eat the fruits and disperse the seeds.

Anthocyanins are more abundant in blueberry, cranberry, rubus, cherry &concord grape.

Anthocyanins are less abundant in banana , pear &potato.

Tannins

Tannins are astringent, bitter plant polyphenols that shrink proteins. Plant usually use them as Defensive tastes.

Tannins are found in leaf tissues, bud tissues, seed tissues, root tissues and stem tissues. They don't interfere with the metabolism process in plant but they are described as interfering with digestive processes, and until more effective synthetics were found, were used to tan animal hides and turn them into leather .

The tea plant is an example of a plant said to have a naturally high tannin content.

The sensation of astringency is caused by the ‘tanning’ of the proteins in the saliva and mucous membranes of the mouth; lubrication is reduced and the surface tissues actually contract .

But if you add milk to your tea, the tannins attack the proteins in the milk rather than those in your mouth, and the taste is much less astringent .

Many fruits have a tannin pigment such as

Pomegranates

Persimmon

Tannin is also found in chocolate. The usual concentration is around 10mg per ml in the liquid form.

Tannins are usually divided chemically into hydrolyzable tannins and condensed tannins.

Condensed tannins are polymers of 2 to 50 (or more) flavonoid units that are joined by carbon-carbon bonds, which are not susceptible to being cleaved by hydrolysis

.

Hydrolyzable tannins (decomposable in water, with which they react to form other substances), yield various water-soluble products, such as gallic acid and protocatechuic acid and sugars. Gallotannin, or common tannic acid, is the best known of the hydrolyzable tannins.

Pigments of plastids(photosynthetic pigments)

Plastids are the major organelles found in plants and algae. Plastids often contain pigments used in photosynthesis.

Photosynthetic pigments are the means by which the energy of sunlight is captured for photosynthesis. However, since each pigment reacts with only a narrow range of the spectrum, there is usually a need to produce several kinds of pigments, each of a different color, to capture more of the sun's energy.

photosynthetic pigments

1-Soluble in organic solvents(Chlorophylls

Carotenoids )

2-Soluble in water (phycobilins)

Chlorophylls

Chlorophyll is the most common pigment present in every plant that performs photosynthesis.

There are various types of chlorophyll but the most common are:

chlorophyll a chlorophyll c

chlorophyll b

Chlorophyll a absorbs well at a wavelength of about 400-450 nm and at 650-700 nm; chlorophyll b at 450-500 nm and at 600-650 nm.

Chemically chlorophylls are pigments which contain a porphyrin ring, a magnesium atom and a hydrocarbon tail .

This is a stable ring-shaped molecule around which electrons are free to migrate. Because the electrons move freely, the ring has the potential to gain or lose electrons easily, and thus the potential to provide energized electrons to other molecules. This is the fundamental process by which chlorophyll "captures" the energy of sunlight.

Chlorophyll a

It is a blue-green pigment. This is the molecule which makes photosynthesis possible, by passing its energized electrons on to molecules which will manufacture sugars

Chlorophyll b

It is a yellow-green pigment.

It has the shown structure.

It occurs only in green algae.

Chlorophyll c

found only in photosynthetic kind of organisms found in aquatic ecosystem

e.g. Chromista and dinoflagellates.

There are 2 types of chlorophyll c:

chlorophyll c1

chlorophyll c2

Carotenoids

They are usually red, orange, or yellow pigments, and include the familiar compound carotene, which gives carrots their color. These compounds are composed of two small six-carbon rings connected by a "chain" of carbon atoms. As a result, they do not dissolve in water, and must be attached to membranes within the cell. Carotenoids cannot transfer sunlight energy directly to the photosynthetic pathway, but must pass their absorbed energy to chlorophyll. For this reason, they are called accessory pigments.

Phycobilins

are water-soluble pigments, and are therefore found in the cytoplasm, or in the stroma of the chloroplast. They occur only in Cyanobacteria and Rhodophyta.

Phycobilins are not only useful to the organisms which use them for soaking up light energy; they have also found use as research tools. Both pycocyanin and phycoerythrin fluoresce at a particular wavelength. This means that when the strong light falls on phycobilins they absorb light energy and release this energy by emitting light of shorter wave length, giving a fluorescent effect.

They are unique among the photosynthetic pigments in that they are bonded to certain water-soluble proteins, known as phycobiliproteins. Phycobiliproteins then pass the light energy to chlorophylls for photosynthesis. The phycobilins are especially efficient at absorbing red, orange, yellow and green light, wavelengths which are not well absorbed by chlorophyll a

Phycobilins may chemically considered as a class of light-sensitive ligands bound to phycobiliproteins and used as accessory light-gathering pigments in algae. The mechanism is described in the entries for phycobiliprotein and phycobilisome. The phycobilins are, like chlorophyll, tetrapyrrole structures. However, unlike chlorophyll, the pyrrole rings are laid out linearly. The detailed structure of four phycobilins commonly found in algae are shown in the next figure

Phycobiliproteins

water soluble fluorescent proteins derived from cyanobacteria and eukaryotic algae. In these organisms, they are used as accessory pigments for photosynthetic light collection. They absorb energy in portions of the visible spectrum that are poorly utilized by chlorophyll and, through fluorescence energy transfer, convey the energy to chlorophyll at the photosynthetic reaction center. ... The phycobiliproteins are composed of a number of subunits, each having a protein backbone to which linear tetrapyrrole chromophores are covalently bound. All phycobiliproteins contain either phycocyanobilin or phycoerythrobilin chromophores, and may also contain one of three minor bilins; phycourobilin, cryptoviolin or the 697-nm bilin

phycobilisome

The phycobiliproteins in many algae are arranged in subcellular structures called phycobilisome.