Friday, November 15, 2013

Is the Sahara on the move?

The southern fringe of the Sahara, known as the Sahel, is believed by some scientists to be advancing by as much as 9 miles (15km) a year. Horrifying reports of drought, starvation and death in Ethiopia, Somalia and Sudan have shocked the world. But is the Sahara really moving southwards or are the devastating crop failures being caused by politics and by bad management of land?
Global warming caused by increased carbon dioxide in the atmosphere from human activities is often blamed for the Sahel famines, but there is little proof. There is, however, plenty of evidence that the climate has fluctuated in log cycles over the past 2 million years. Stone Age paintings depict antelopes, elephants and lions at Tassili N’Ajjer in the Algerian Sahara. And roman cities all over North Africa, such as Leptis Magna in Libya, once ruled over the granaries of the Roman Empire where fields grew grain – without any need for irrigation – to be exported to Rome. Now the former farms are dusty plains of semi-desert. This is part of the natural climatic cycle – each cycle taking thousands of years – that is brought about by changes in the Earth’s orbit around the Sun. it is the same cycle that caused the Ice Ages, and could now be at work to cause the Sahara to march in the Sahel.
However, the growth of deserts can also be blamed on man’s treatment of the land. Cutting down trees and scrub to open up land for farming can expose soil to the ravages of erosion. Bad management of land on slopes, such as ploughing furrows up and down a hill instead of around it, can cause soil to be washed down or blown away. Bad farming practice in the American Midwest during the 1930s reduced an area of farm land nearly the size of England to a dust bowl. This type of soil erosion happens on the edges of the Sahara when grassland with poor oil is ploughed up to grow crops.
 ‘Over-grazing’ by farm animals is also alleged to cause erosion, but the evidence is inconclusive. Animals can actually encourage plant growth by fertilizing the soil with their manure. Nomadic farmers, who have roamed and flourished in the deserts for thousands of years, never stay in one place for long. They move their flocks frequently, giving grass time to grow again. Only if they are stopped from moving on will their animals over-graze the land.
In the short term, politics are probably as strong a factor as climate change in causing the Sahel famines. Wars in Ethiopia and Somalia have forced refugees to migrate into semi-arid land that cannot support them. Social and economic pressures, such as government settlement policies, have also forced people to give up traditional nomadic farming and change to static Western farming methods that are not suited to the land and climate, and so lead to ‘dust bowls’.

Climatic change is an easy scapegoat for countries suffering from famine, but the case has not yet been proved.

Saturday, March 10, 2012

What does the brain have to do with temperature?

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In order for the 100 trillion or so cells in the human body to work efficiently, they need a constant environment. For most persons, this is a temperature of 98.6 degree F (37 degree C) or so. When the body temperature deviates even a little, the person is likely to feel ill.

Apart of the brain, the hypothalamus, acts as the body's thermostat, maintaining this steady temperature no matter how hot or cold the weather. Though the extremities may be chilled, the body's core - and the brain - are protected.

Neurons in the hypothalamus constantly monitor blood flowing through it. When blood temperature rises, the hypothalamus promptly sends out messages through the autonomic nervous system, producing sweat and dilating the blood vessels in the skin.

Low body temperatures, picked up by sensors in the skin, signal the blood vessels in the skin to constrict. The muscles begin to produce heat-generating shivers. Your teeth start to chatter, and goose bumps appear as the fine hairs on the skin stand on end. In addition, the hypothalamus causes the release of the hormones epinephrine and norepinephrine into into the blood. These hormones temporarily increase the body's metabolic rate and produce heat.

Monday, March 05, 2012

Does Amnesia Erase Memories?

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During the 1940's and 1950's, when severe epileptic disorders were treated by surgically removing part of the brain, doctors found that electrical stimulation of the hippocampus provoked a flood of memories in their patients. Removal of or damage to the hippocampus made it impossible for patients to learn anything new, and at the same time erased memories of events within the past three years. Only older memories were left intact. This kind of amnesia (loss of memory) has proved to be permanent.

Progressive loss of memory is the dire result of Alzheimer's disease, a degeneration of the brain that generally strikes in old age. This, too, is an irreversible loss.

A head injury can also cause amnesia, but often the effect is temporary. For example, the victim of a car crash may lose memories of events just prior to the accident. Scientists call this retrograde amnesia.

Severe emotional stress is another cause of amnesia. Victims of crime and battle-scarred soldiers may protect themselves from the horrors they have experienced by blotting out the memory.. Such a mechanism may seem merciful, but can result in deeper emotional trouble, for, it seems, these memories are not lost. Unless the past is retrieved and faced, the stress may fester.

Friday, March 02, 2012

Amazing Bible Facts and Statistics

The system of chapters was introduced in A.D. 1238 by Cardinal Hugo de S. Caro, while the verse notations were added in 1551 by Robertus Stephanus, after the advent of printing.

A Bible in the University of Gottingen is written on 2,470 palm leaves.

According to statistics from Wycliffe International, the Society of Gideons, and the International Bible Society, the number of new Bibles that are sold, given away, or otherwise distributed in the United States is about 168,000 per day.

The Bible can be read aloud in 70 hours.

There are 8,674 different Hebrew words in the Bible, 5,624 different Greek words, and 12,143 different English words in the King James Version.

A number of verses in the Bible (KJV) contain all but 1 letter of the alphabet: Ezra 7:21 contains all but the letter j; Joshua 7:24, 1st Kings 1:9, 1st Chronicles 12:40, 2nd Chronicles 36:10, Ezekiel 28:13, Daniel 4:37, and Haggai 1:1 contain all but q; 2 Kings 16:15 and 1st Chronicles 4:10 contain all but z; and Galatians 1:14 contains all but k.


Number of books in the Bible: 66
Chapters: 1,189
Verses: 31,101
Words: 783,137
Letters: 3,566,480
Number of promises given in the Bible: 1,260
Commands: 6,468
Predictions: over 8,000
Fulfilled prophecy: 3,268 verses
Unfulfilled prophecy: 3,140
Number of questions: 3,294
Longest name: Mahershalalhashbaz (Isaiah 8:1)
Longest verse: Esther 8:9 (78 words)
Shortest verse: John 11:35 (2 words: "Jesus wept").
Middle books: Micah and Nahum
Middle verse: Psalm 118:8
Middle chapter: Psalm 117
Shortest chapter (by number of words): Psalm 117 (by number of words)
Longest book: Psalms (150 chapters)
Shortest book (by number of words): 3 John
Longest chapter: Psalm 119 (176 verses)
Number of times the word "God" appears: 3,358
Number of times the word "Lord" appears: 7,736
Number of different authors: 40
Number of languages the Bible has been translated into: over 1,200


Number of books: 39
Chapters: 929
Verses: 23,114
Words: 602,585
Letters: 2,278,100
Middle book: Proverbs
Middle chapter: Job 20
Middle verses: 2 Chronicles 20:17,18
Smallest book: Obadiah
Shortest verse: 1 Chronicles 1:25
Longest verse: Esther 8:9
Longest chapter: Psalms 119
Largest book: Psalms


Number of books: 27
Chapters: 260
Verses: 7,957
Words: 180,552
Letters: 838,380
Middle book: 2 Thessalonians
Middle chapters: Romans 8, 9
Middle verse: Acts 27:17
Smallest book: 3 John
Shortest verse: John 11:35
Longest verse: Revelation 20:4
Longest chapter: Luke 1
Largest book: Luke


What causes giantism and dwarfism?

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Being very tall or short does not constitute either giantism or dwarfism. Men and women can range in height from 4 feet 7 inches (140 centimeters to 6 feet 7 inches (201 cm) and still be considered normal.

Giantism and dwarfism are specific growth disorders that can usually be traced to something that has gone awry in the pituitary, but sometimes dwarfism can be caused by malnutrition or by diseases of the kidney, heart, or liver. As a rule, too much GH (growth hormone) leads to giantism and too little to dwarfism, but the timing of the secretions is also important.

If the pituitary overproduces GH before the end of adolescence, the outcome is likely to be excessive growth. But if the oversecretion comes after adolescence, the hormone acts unevenly. Because growth in stature has essentially ceased, and because GH acts only on the parts of the skeleton still not completely hardened by mineralization, the excess hormone may cause large extremities or, in rare instances, a condition called acromegaly, marked by enlargement of the face, feet, and hands.