ScienceIQ.com

Why Is Blood Pressure Two Numbers?

Blood pressure might better be called heart pressure, for the heart's pumping action creates it. To measure blood pressure, health workers determine how hard the blood is pushing at two different times: when the heart contracts, called systole; and when the heart relaxes, called diastole. The contraction of the ventricles during systole gives the ...

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WhyIsBloodPressureTwoNumbers
Engineering

What Are Composite Materials?

A composite material is one in which two or more separate materials have been combined to make a single construct having more desirable properties. What many people don't realize is that composites ... Continue reading

CompositeMaterials
Medicine

What Is Sickle Cell Anemia?

Sickle cell anemia is an inherited blood disease. That means you are born with it and it lasts a lifetime. Sickle cell anemia affects the red blood cells. Normal red blood cells are smooth and round ... Continue reading

WhatIsSickleCellAnemia
Astronomy

A Satellite Of Our Own

The regular daily and monthly rhythms of Earth's only natural satellite, the Moon, have guided timekeepers for thousands of years. Its influence on Earth's cycles, notably tides, has also been charted ... Continue reading

ASatelliteOfOurOwn
Biology

Microarrays: Chipping Away At The Mysteries Of Science And Medicine

With only a few exceptions, every cell of the body contains a full set of chromosomes and identical genes. Only a fraction of these genes are turned on, however, and it is the subset that is ... Continue reading

Microarrays

Food Irradiation: A Safe Measure

FoodIrradiationASafeMeasureFood safety is a subject of growing importance to consumers. One reason is the emergence of new types of harmful bacteria or evolving forms of older ones that can cause serious illness. A relatively new strain of E. coli, for example, has caused severe, and in some cases life-threatening, outbreaks of food-borne illness through contaminated products such as ground beef and unpasteurized fruit juices. Scientists, regulators and lawmakers, working to determine how best to combat food-borne illness, are encouraging the use of technologies that can enhance the safety of the nation's food supply. Many health experts agree that using a process called irradiation can be an effective way to help reduce food-borne hazards and ensure that harmful organisms are not in the foods we buy. During irradiation, foods are exposed briefly to a radiant energy source such as gamma rays or electron beams within a shielded facility.

Irradiation is not a substitute for proper food manufacturing and handling procedures. But the process, especially when used to treat meat and poultry products, can kill harmful bacteria, greatly reducing potential hazards. The Food and Drug Administration has approved irradiation of meat and poultry and allows its use for a variety of other foods, including fresh fruits and vegetables, and spices. The agency determined that the process is safe and effective in decreasing or eliminating harmful bacteria. Irradiation also reduces spoilage bacteria, insects and parasites, and in certain fruits and vegetables it inhibits sprouting and delays ripening. For example, irradiated strawberries stay unspoiled up to three weeks, versus three to five days for untreated berries. Food irradiation is allowed in nearly 40 countries and is endorsed by the World Health Organization, the American Medical Association and many other organizations.

Irradiation does not make foods radioactive, just as an airport luggage scanner does not make luggage radioactive. Nor does it cause harmful chemical changes. The process may cause a small loss of nutrients but no more so than with other processing methods such as cooking, canning, or heat pasteurization. Federal rules require irradiated foods to be labeled as such to distinguish them from non-irradiated foods.