Bloogg - Anything and Everything

Paralysis

Riaan — Sat, 20 Oct 2007 08:49:50 +0000

Definition

Paralysis is defined as complete loss of strength in an affected limb or muscle group.

Description

The chain of nerve cells that runs from the brain through the spinal cord out to the muscle is called the motor pathway. Normal muscle function requires intact connections all along this motor pathway. Damage at any point reduces the brain’s ability to control the muscle’s movements. This reduced efficiency causes weakness, also called paresis. Complete loss of communication prevents any willed movement at all. This lack of control is called paralysis. Certain inherited abnormalities in muscle cause periodic paralysis, in which the weakness comes and goes. (more…)

Microsoft mind reader

Riaan — Sat, 20 Oct 2007 07:38:14 +0000

Not content with running your computer, Microsoft now wants to read your mind too.

The company says that it is hard to properly evaluate the way people interact with computers since questioning them at the time is distracting and asking questions later may not produce reliable answers. “Human beings are often poor reporters of their own actions,” the company says.

Instead, Microsoft wants to read the data straight from the user’s brain as he or she works away. They plan to do this using electroencephalograms (EEGs) to record electrical signals within the brain. The trouble is that EEG data is filled with artefacts caused, for example, by blinking or involuntary actions, and this is hard to tease apart from the cognitive data that Microsoft would like to study. (more…)

New Gadget: Drive with poor vision

Riaan — Sat, 20 Oct 2007 07:31:57 +0000

Everyone knows it is not safe to drive around if you have poor vision, but Spanish researchers hope to overcome that problem by successfully developing and testing a computer simulator that actually enables the visually impaired to drive. This system is known as SERBA (short for ‘Sistema Electro-óptico Reconfigurable de ayuda para Baja Visión’), when translation to English means ‘Reconfigurable Electric-Optical System for Low Vision’. It uses an innovative system that is based on a reconfigurable device known as FPGA (or Field Programmable Gate Array). In layman’s terms, the SERBA system can be reprogrammed easily under different and changing circumstances. Whenever a user’s vision declines, all they need to do is download a new version of the software that has been adapted to cater for this new environment without the need to purchase a new device. Guess this is a high tech version of changing the lens in your glasses without picking up a new frame.

Any driver using the SERBA system will have to use the transparent viewfinder that makes him/her look like part of the Borg collective. Using a real-time video processing system that stores a number of image processing algorithms, it is capable of adapting to the user’s needs and to the evolution of their disease. To date, eight patients who are suffering from Retinitis Pigmentosa (a visual impairment that reduces the field of vision) were involved in the device’s assessment, along with half a dozen others suffering from different pathologies that generate a loss of sharpness of vision, with rather encouraging results.

The software itself can be updated via an Internet connection, where the program will then be stored in the internal memory of the prototype board while the selection of the dump algorithm in the FPGA is carried out automatically. The images shown in the transparent viewfinder are no different than those used in the army, but I guess there is a limit to this technology if the disease gets progressively worse (touch wood). Still, it is great to know that such technology provides a greater degree of mobility for older folks as well as those suffering from visual impairment of some sort.

How Great is the Amazon River?

Riaan — Fri, 19 Oct 2007 07:27:03 +0000

The Amazon is the greatest river in the world by so many measures; the volume of water it carries to the sea (approximately 20% of all the freshwater discharge into the oceans), the area of land that drains into it, and its length and width. It is one of the longest rivers in the world and, depending upon who you talk to, is anywhere between 6,259km/3,903mi and 6,712km/4,195mi long.

At its widest point the Amazon River can be 11km/6.8 mi wide during the dry season. The area covered by the Amazon River and its tributaries more than triples over the course of a year. In an average dry season 110,000 square km of land are water-covered, while in the wet season the flooded area of the Amazon Basin rises to 350,000 square km. When the flood plains and the Amazon River Basin flood during the rainy season the Amazon River can be up to 40km/24.8 mi wide. Where the Amazon opens at its estuary the river is over 325km/202 mi wide!

Because the Amazon drains the entire Northern half of the South American continent (approx. 40% landmass), including all the torrential tropical rains that deluge the rainforests, it carries an enormous amount of water. The mouth of the Amazon River, where it meets the sea, is so wide and deep that ocean-going ships have navigated its waters and traveled as far inland as two-thirds the way up the entire length of the river.

The Amazon - Home of Extremes

The Amazon River is not only the greatest in the world, it is home to many other “Extremes” of the natural world. Have you ever seen a catfish? They’re usually found in warm, slow moving waters of lakes and streams, and some people keep them as pets in aquariums. Catfish are pretty creepy looking fish with big flat heads and “whiskers” on either side of their heads (hence the name, catfish). Most catfish that we’re familiar with here in the U.S. are anywhere from eight inches long to about five feet, weighing in at up to 60 pounds. But the catfish that live in the world’s greatest river have all the room in the world to grow as big as nature will allow - they have been captured weighing over 200 pounds! One of the largest freshwater fish in the world is found living in the waters of the Amazon River. Arapaima, also known locally as Pirarucu, Arapaima gigas are the largest, exclusively fresh water fish in the world. They have been found to reach a length of 15 ft/4m and can weigh up to 440lbs/200kg. And yes, for you smartypants out there, sturgeon are even larger than this, but they are not exclusively freshwater fish. Sturgeon spend most of their lives at sea, or in brackish water, and only swim into freshwater rivers to spawn. (Read about the biggest freshwater fish in the world.)

The Amazon is also home to some other extreme creatures, featured here in “Extreme Science”; the Anaconda (biggest snake), and Piranha (most ferocious). Check it out!

Amazon River Facts

So, how did the Amazon get to be so big? The first reason has to do with its location - right at the equator. Around the “belt line” of the earth lies a warm, tropical zone where over 400 in/1016cm of rain fall every year. That averages out to more than an inch (3cm) of rain, everyday! A lot of water falls onto the land surrounding the river, what is called the “Amazon River drainage basin”. A good way to understand what a drainage basin is to think of the whole northern half of the continent of South America as a shallow dish, or saucer. Whenever rain falls and lands anywhere in the river basin it all runs into the lowest place in the pan, which happens to be the Amazon River. The sheer volume of rain in the Amazon jungle, as well as the slope of the surrounding land, combine to create the enormous river known as the Amazon.

Mount Everest

Riaan — Fri, 19 Oct 2007 07:16:59 +0000

Mount Everest is so famous for being so high that you’ve probably heard of it before. It has been known the world over since the early 1950s when Sir Edmund Hillary and Tenzig Norgay first climbed to its awesome summit. Hillary surveyed Everest at the time and determined that it was 29,000 ft/8840m high - a figure amazingly close to the current reading of 29,035 ft/8850m, which was confirmed using radar and global positioning satellite (GPS) technology. (more…)

Diamond cutting process

Riaan — Fri, 19 Oct 2007 07:12:57 +0000

Planning

Diamond manufacturers analyse diamond rough from an economic perspective, with two objectives steering decisions made about how a faceted diamond will be cut. The first objective is that of maximum return on investment for the piece of diamond rough. The second is how quickly the finished diamond can be sold. Scanning devices are used to get 3-dimensional computer model of the rough stone. Also, inclusions are photographed and placed on the 3D model, which is then used to find an optimal way to cut the stone. (more…)

Huge crowds greet Bhutto return

Riaan — Thu, 18 Oct 2007 07:12:02 +0000

Benazir Bhutto has begun a triumphant open-top bus procession from Karachi airport to the city centre, after her dramatic return to Pakistan.

Hundreds of thousands of people are packing the streets, hoping to glimpse the ex-prime minister, who has returned from eight years of self-imposed exile.

She is set to hold power-sharing talks with President Pervez Musharraf, which could see her becoming PM again.

There is a huge security presence amid Islamist assassination threats.

Ms Bhutto was accompanied on the flight from Dubai by about 100 members of her Pakistan People’s Party (PPP). (more…)

South Africa unchanged for final

Riaan — Thu, 18 Oct 2007 07:09:21 +0000

South Africa have named an unchanged starting XV from the side which beat Argentina to face champions England in the World Cup final on Saturday. Coach Jake White has made one change to the replacements bench, with flanker Wikus van Heerden returning at the expense of ex-skipper Bob Skinstad.

The starting XV has 668 caps and will be their most experienced side ever.

England have already met the Boks in France, with South Africa romping to a 36-0 victory in the group stages. –>

Our First Lunar Program: What did we get From Apollo?

Riaan — Thu, 18 Oct 2007 07:06:19 +0000

American plans now call for a return of humans to the Moon by around 2020. What can we hope to gain from such a program? It will be helpful to look back at our first lunar program, Apollo, and ask what we got from it, beside some 850 pounds of rock and soil – fascinating to geologists, but perhaps not to all taxpayers. I will try to summarize highlights of the payoff from Apollo.

What was the “Apollo Program”? There was much more to it than Neil Armstrong’s “one small step,” and even more than the following five lunar landings – any one of which would have been a gigantic accomplishment. First, Apollo began with the Gemini Program, which was solely a technological warm-up for Apollo. Gemini was the first true American spaceship, with propulsion, radar, on-board computers, and extravehicular activity (“space walk”) capability. Ten manned Gemini missions were flown, developing the technological and operational capability needed for the following lunar program. However, the Gemini astronauts carried out many scientific experiments, in addition to practicing various space-flight techniques such as orbital rendezvous. (more…)

The Combustion Engine

Riaan — Mon, 15 Oct 2007 09:14:32 +0000

An internal combustion engine is any engine that operates by burning its fuel inside the engine. In contrast a steam engine burns its fuel outside the engine. The most common internal combustion engine type is gasoline powered. Others include those fueled by diesel, hydrogen, methane, propane, etc. Engines typically can only run on one type of fuel and require adaptations to adjust the air/fuel ratio or mix to use other fuels.

In a gasoline engine, a mixture of gasoline and air is sprayed into a cylinder. This is compressed by a piston and at optimal point in the compression stroke, a spark plug creates an electrical spark that ignites the fuel. The combustion of the fuel results in the generation of heat, and the hot gases that are in the cylinder are then at a higher pressure than the fuel-air mixture and so drive the piston back down. These combustion gases are vented and the fuel-air mixture reintroduced to run a second stroke. The outward linear motion of the piston is ordinarily harnessed by a crankshaft to produce circular motion. Valves control the intake of air-fuel mixture and allow exhaust gasses to exit at the appropriate times. (more…)