Near-Earth Supernovas

Supernovas near Earth are rare today, but during the Pliocene era of Australopithecus supernovas happened more often. Their source was an interstellar cloud called 'Sco-Cen' that was slowly gliding by the solar system. Within it, dense knots coalesced to form short-lived massive stars, which exploded like popcorn. ...

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If You're Bringing Cows, Bring Your Own Decomposers

Living organisms create a lot of waste products. Every year they deposit millions of tons of dead plant and animal matter on almost every corner of the earth - and they make dung, lots of dung. Where ... Continue reading


Leaning Wonder of Engineering

Most everyone is familiar with the famous Leaning Tower of Pisa. It's known not so much for its engineering, as for the fact that it hasn't fallen yet. From an engineering standpoint, it is a study in ... Continue reading


X-Ray Astronomy vs. Medical X-Rays

It's natural to associate the X-rays from cosmic objects with an X-ray from the doctor's office, but the comparison is a bit tricky. A doctor's X-ray machine consists of two parts: an X-ray source at ... Continue reading


Big Boom

They sound like thunder, but they're not. They're sonic booms, concentrated blasts of sound waves created as vehicles travel faster than the speed of sound. To understand how the booms are created, ... Continue reading


What Is Sickle Cell Anemia?

WhatIsSickleCellAnemiaSickle 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 like doughnuts. They move easily through blood vessels to carry oxygen to all parts of the body. In sickle cell anemia, the red blood cells become hard, sticky, and shaped like sickles or crescents. When these hard and pointed red cells go through the small blood vessels, they tend to get stuck and block the flow of blood. This can cause pain, damage, and a low blood count or anemia.

Anemia is a shortage of red blood cells in your blood. In sickle cell anemia, this shortage of red blood cells occurs because sickle cells do not last very long. It is hard for your body to make new red blood cells fast enough to keep up. Normal red blood cells last about 120 days in the bloodstream. Sickle cells die after only about 10 to 20 days. Sickle cell trait is different from sickle cell anemia. A person with sickle cell trait does not have the disease but carries the gene that causes the disease. Persons with sickle cell trait can pass the gene to their children.

Sickle cell anemia is a serious disease and there is no universal cure. Bone marrow transplantation offers a cure, but very few patients have matched donors. Some patients also do not want bone marrow transplants because of the risks involved. Over the past 30 years, doctors have learned a great deal about the disease. They know what causes it, what it does to your body, and how to treat many of the complications. Today, with good health care, many people with the disease are in reasonably good health much of the time, live fairly normal lives and live 40 to 50 years and longer.