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Friday 24 June 2011
The Neck
The neck is an upward extension of the spine beyond the body, designed to support and serve the needs of the head. It is amazingly designed and highly engineered so its underlying very complex function goes on in the background without us having to think about it. We can move and stop the motion of our heads very quickly, placing it very precisely within its very large range of motion, despite its weight and the leverage of its position. The head bears most of our very important sensory organs so the neck's job is to put the head where it can perform its sensory function best.The structure of the neck region consists of discs, muscles, joints, bones and ligaments but it is worth ensuring that we do not forget the nervous components which are so important up here close to the brain. The comprehensive nervous control of the area facilitates movement, accepts incoming information for movement planning and controls circulatory responses. The function of the cervical spine is a compromise between the subtle control mechanisms needed and the requirement to provide as much range of joint movement as possible.Mechanical symptoms are the initial and obvious symptoms from the neck, with postures and activities causing the pain to vary in severity. Loss of range of motion and pain symptoms of various kinds are typical complaints but other problems related to the neck can be difficulties with balance, disturbed vision, dizziness, headaches, mental stresses and muscle weakness. If the physiotherapist can settle the muscle and joint dysfunctions in the neck then all the other symptoms can be positively affected also.Large degrees of joint mobility are present in the cervical spinal region and this is partly made possible by the greater thickness of the intervertebral discs in the cervical region compared to the other spinal areas. Larger ranges of movement are possible with thicker discs, and the facet joints are structurally larger than similar joints in any other spinal areas. The large gliding motions which are possible in the neck allow its high levels of mobility in the compromise between mobility and stability in the spine.The vertebrae in the upper neck, particularly the two upper ones called the atlas and axis, are of a very different shape to the remaining neck vertebrae. These bones are specially designed to work with the movements and stability of the skull and the C1 and C2 articulation is a structure well suited to rotatory movements and makes up much of the neck's rotatory ability. The neck has a very great range of motion with the typical movements of side flexions, flexion, extension and rotations, enabling us to position our faces in a varied combination of positions and angles to allow us to do what we need to do.The neck is helped in its mobility and stability by the thoracic spine beneath it, which allows an increased range of the neck and without which the neck would have to cope with much increased loads at each end of its span where it meets different structures such as the thorax and the skull. The head sits on top of the long tower of the cervical spine with the stabilising guy ropes of the muscles allowing the head to be placed in space accurately without shifting repeatedly. The head is a weighty object and is placed anterior to the centre of gravity, forcing the muscular stabilisers to require endurance and strength to keep the head still so our sense organs can function.The flexor muscles of the neck are at the front and do not have a very difficult job, only working hard when we get up from lying on the back. The extensor muscles, however, are designed to hold our heads up and have to do it for many hours a day, frequently for the whole day. They only go off line when we lie down or start to nod off in a train for example, as our heads fall forward without the support of the extensors. Looking at the neck muscles it can be seen that although they may balance the neck there is significant downward compressive forces produced on the neck structures.
The neck is an upward extension of the spine beyond the body, designed to support and serve the needs of the head. It is amazingly designed and highly engineered so its underlying very complex function goes on in the background without us having to think about it. We can move and stop the motion of our heads very quickly, placing it very precisely within its very large range of motion, despite its weight and the leverage of its position. The head bears most of our very important sensory organs so the neck's job is to put the head where it can perform its sensory function best.The structure of the neck region consists of discs, muscles, joints, bones and ligaments but it is worth ensuring that we do not forget the nervous components which are so important up here close to the brain. The comprehensive nervous control of the area facilitates movement, accepts incoming information for movement planning and controls circulatory responses. The function of the cervical spine is a compromise between the subtle control mechanisms needed and the requirement to provide as much range of joint movement as possible.Mechanical symptoms are the initial and obvious symptoms from the neck, with postures and activities causing the pain to vary in severity. Loss of range of motion and pain symptoms of various kinds are typical complaints but other problems related to the neck can be difficulties with balance, disturbed vision, dizziness, headaches, mental stresses and muscle weakness. If the physiotherapist can settle the muscle and joint dysfunctions in the neck then all the other symptoms can be positively affected also.Large degrees of joint mobility are present in the cervical spinal region and this is partly made possible by the greater thickness of the intervertebral discs in the cervical region compared to the other spinal areas. Larger ranges of movement are possible with thicker discs, and the facet joints are structurally larger than similar joints in any other spinal areas. The large gliding motions which are possible in the neck allow its high levels of mobility in the compromise between mobility and stability in the spine.The vertebrae in the upper neck, particularly the two upper ones called the atlas and axis, are of a very different shape to the remaining neck vertebrae. These bones are specially designed to work with the movements and stability of the skull and the C1 and C2 articulation is a structure well suited to rotatory movements and makes up much of the neck's rotatory ability. The neck has a very great range of motion with the typical movements of side flexions, flexion, extension and rotations, enabling us to position our faces in a varied combination of positions and angles to allow us to do what we need to do.The neck is helped in its mobility and stability by the thoracic spine beneath it, which allows an increased range of the neck and without which the neck would have to cope with much increased loads at each end of its span where it meets different structures such as the thorax and the skull. The head sits on top of the long tower of the cervical spine with the stabilising guy ropes of the muscles allowing the head to be placed in space accurately without shifting repeatedly. The head is a weighty object and is placed anterior to the centre of gravity, forcing the muscular stabilisers to require endurance and strength to keep the head still so our sense organs can function.The flexor muscles of the neck are at the front and do not have a very difficult job, only working hard when we get up from lying on the back. The extensor muscles, however, are designed to hold our heads up and have to do it for many hours a day, frequently for the whole day. They only go off line when we lie down or start to nod off in a train for example, as our heads fall forward without the support of the extensors. Looking at the neck muscles it can be seen that although they may balance the neck there is significant downward compressive forces produced on the neck structures.
Watering the Air The average temperature around the world is rising. People living in the U.S. Midwest might find this fact hard to believe, though. Two new studies show that in America’s heartland, summers are now cooler and wetter than they were in years past. The scientists suggest that the change in the Midwest climate may have happened because of farming. The first study was led by David Changnon, a climatologist at Northern Illinois University in DeKalb. He presented one of the studies in January during a meeting of scientists who study weather and climate. A climatologist studies the climate of an area, which includes measuring rainfall, temperature and wind. Climatologists want to know how these factors have changed in the past, and how they’ll change in the future. [Image] Crops of soybean and corn (pictured) are the main type planted in the Midwest. Purdue9394/iStockphoto Changnon and his team studied temperature records from Chicago and 13 other sites in the Midwest. They found that since 1970, the average temperature in Illinois and Iowa during July and August has gone down — by up to one degree Fahrenheit — from what it was during the years between 1930 and 1969. Their investigation also showed that the average rainfall in those two states during those two months has increased. Between 1970 and 2009, about 0.33 inches more rain fell than between 1930 and 1969. These two changes — lower temperatures and more rainfall — may be connected by humidity, Changnon says. Humidity is the measure of how much moisture is in the air. Humid air, which contains a lot of moisture, takes longer to heat up than dry air, Changnon notes. And humid air often releases its moisture through rainfall. So where did the extra moisture in the air come from? Changnon points to farms in the region. As plants grow, they pull moisture from the ground and release it into the air. And among plants, soybean and corn plants release a lot of moisture. Midwestern farms now plant more soybeans and corn than in the past, with 97 percent of farmland today planted with these two crops. In the 1930s, corn and soybeans covered only about 57 percent, Changnon says. He also notes that the plants are planted closer together now than they used to be, so there are more plants per acre than in the past. The second study, like Changnon’s, also found an increase in rainfall in the same area. But it points to another possible source for the increased moisture. Alan Robock of the Center for Environmental Prediction at Rutgers University in New Brunswick, N.J., was part of the team that produced the second study and presented the group’s findings at the same meeting as Changnon. The group includes Ying Fan, who led the study, and Anthony DeAngelis, M. D. Kustu and D. A. Robinson, all from Rutgers University. The team found that irrigation practices in the Great Plains have changed over the years. (Irrigation is how farmers get water to crops, especially crops far from a river or other body of water. Irrigation is a way of bringing water to those crops all the time.) The researchers studied a vast area of the United States that stretches from South Dakota to Oklahoma and the Texas panhandle. They found that in 1930, farmers in that region irrigated only about 1.8 million acres of farmland, an amount roughly half the size of Connecticut. In 1980, however, farmers irrigated nearly 15 million acres — more land than Vermont and New Hampshire combined. Much of this irrigation uses water from natural reservoirs, such as those that are underground. Plants use the water and then release it into the air, so irrigating more and more plants means that more and more water makes it into the air. Robock suspects that as farms in the Great Plains received more irrigation, they released more moisture into the air — which then was carried downwind to the Midwest, where it caused more rain. These results by Changnon and Robock and his colleagues are the first step toward understanding a change in the weather. But it will take more studies before crop irrigation can definitely be blamed for changes in temperature and rainfall. |
Changes in 'Good' Fatty Acid Concentration of Inner Organs Might Be Largely Independent of Diet Animal cell membranes are a bilayer of phospholipids (charged fat molecules) made up to various degrees of fatty acids that must be acquired from the diet. The essential polyunsaturated fatty acids have been shown to be important in resistance to a variety of diseases and in coping with changes in body temperature. It is generally believed that mammals are unable to alter the proportions of essential fatty acids in their cell membranes except by changing their diets. Furthermore, mammals are unlikely candidates for extensive temperature-induced alteration, known to occur in fish or reptiles, because they typically maintain high and rather constant body temperatures.Arnold and colleagues at the Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna have investigated changes in the fatty-acid composition of cell membranes in an exceptional model, wild-living alpine marmots. As typical hibernators, alpine marmots lower their body temperatures to close to the ambient temperature throughout most of the winter. Even during the regular interruptions of hibernation their body temperature remains a few degrees below typical summer levels. Amazingly, the amount of so-called "n-6" polyunsaturated fatty acids (those with the final double bond at the sixth position) in the membranes was found to increase dramatically before the start of hibernation, apparently to prepare the body, and particularly the heart, for operation at very low temperatures. Consistent with this idea, the transition to a higher content of n-6 fatty acids in membranes takes place extremely rapidly just before the animals enter their hibernation chambers. The changes are reversed, again over a short time, around the termination of hibernation in spring, when the animals return to a life at high body temperatures.A selective process for membrane remodellingThe fatty acids incorporated in the membranes probably stem from the marmots' white adipose tissue. Surprisingly, however, fatty acids are not simply taken from the fat stores at random but n-6 polyunsaturated fatty acids are transported preferentially, although the mechanism remains a mystery.These new and unexpected findings show that mammals can make highly significant and rapid seasonal changes to the lipid composition of their cell membranes. But the results go far beyond this. During and immediately after hibernation marmots are unable to eat anything -- their food is under a thick layer of snow -- so the changes cannot be related to immediate dietary influences. Instead, the work of Arnold's group strongly implies that animals have specific ways of transporting individual (groups of) fatty acids in the body. And because the animals hibernate underground, isolated from any external signals, the changes are probably controlled by an endogenous clock as part of an annual cycle.It seems unlikely that the mechanisms are specific to animals that hibernate. All mammals -- including humans -- reduce their body temperature to some extent during winter, so the results are directly applicable to us. As Arnold says, "the humble marmot could revolutionize our way of thinking about fatty acid metabolism. The idea that changes in the essential fatty acid content of membranes can only be made via the diet is clearly too simple." To illustrate the importance of the subject, Arnold notes further that "the incidence of heart attacks in humans, well known to increase when membranes contain a high n-6 to n-3 ratio, peaks at the end of winter." Could this relate to a conserved seasonal peak of n-6 polyunsaturated fatty acid concentrations in heart muscle |
Laser Science article When the buzz on lasers as an anti-aging tool first started in the early 1990s, people didn’t know what to make of it. To most people, lasers were symbols of the kind of high-tech wizardry associated with the characters in Star Wars. Faster than the speed of light, however, lasers went from being a novel idea of the future to a much-improved alternative to the cosmetic procedures that already existed.Almost five years later, laser technology has evolved into a mighty presence in cosmetic improvements. In the past, lasers were limited to the treatment of certain cosmetic conditions, such as birthmarks, that affected only a small group of people.All this changed with the introduction of the carbon dioxide (C02) laser, the first of its kind to actually resurface the skin. Before the C02 laser, the only other procedure that could regenerate the superficial and deep layers of skin was a deep phenol peel and dermabrasion. Not long afterward, it seemed as if new cosmetic lasers were being introduced every day.A lot of patients say that they’re afraid of lasers— usually because they assume that there’s only one type of (scary) laser—but they are reassured after knowing that “lasers” is just an umbrella term encompassing different treatments. This situation is comparable to airplanes and cars, which are different forms of transportation with similar engineering characteristics.So, how does a laser work? It works by focusing a beam of light amplified into the skin; when the beam hits the skin, it then attracts to certain components; ie, a laser for brown spots is attracted to melanin, or pigment, and a vascular laser attracts to the red blood vessels. Since the subject of lasers is vast enough to fill an entire book, we will limit our discussion to the cosmetic lasers that are indispensable for bringing out your beauty. Some skin problems with Leaser * warts* port wine stains and birthmarks* remove tattoo | 18/04/2011 | by Technology |
Technical Information INFORMATION TECHNOLOGY In today's expanding and growing environment everything is available within a short moment of time. Every scalable knowledge is available at no time. Be one in the thick jungles of Amazon or in the uninhabited Moore's Island, information is readily available. One should only know how to access such information . After Industrial Revolution, it is now time for Information Revolution. Information Techology (IT) has revolutionised society with miniaturisation of machines of industrial revolution with silicon chips. Silicon Valley situated in the US shows to the world how the technology ca be tapered to better needs of humans. Now most youngsters dream to be part of the Silicon Valley. India, at present, is an important juncture in its history, having completed the transition from an agrarian economy to a full-fledged, first-world economy, operating at he leading edge of contemporary technology. A key element in taking the country forward and maintaining its growth momentum, wil be the provision of a highly skilled and competent global workforce. This is possible with the current lead India has in Information Technology. The IT sector is one of the most promising sectors. It is growing at an unprecedented rate. Developing nations like India, the Philippines, and China are leading the undercurrent and spurt in the IT revolution. The steady growth of IT sector in India is definitely a bonus opportunityfor fresh graduates and young professionals. The number of job opportunities for these young professionals are growing at an unprecedented rate. Gone are the days when M.Tech., Ph.D's in computer streams used to lead the way. Now young energetic professionals with a high aptitude and with degrees like B.Tech. or MCAs or like simple Diploma course from different institutes with expertise in one particular domain hold the nerve of the market. According to recent NASSCOM estimate, the Indian Information, Communication and Tele-communication (ICT) industry will contribute 7 percent to the country's GDP by 2009, providing direct employment to more than 2.2 million people and indirect employment nearly twice that number. The hardware sector grew at a significant 34 percent during 2003-04, raising the revenues from US$ 3.6 billion in 2002-03 to US$ 4.8 billion. The 2004-05 revenues of this sector grew to US$ 6 billion . Domestic demand for IT hardware components grew from US$ 3.3 billion in 2003-04, with hardware systems accounting for more than half of the segment revenues during this period. Skill Sets Required :The field of computers is an applied field where one needs to have a lot of analytical skills and aptitude for problem solving. The first step towards problem solving is interaction with the client to know the nature of the problem. For this one should have oral as well as written communication skills. One should also have better negotiation skills. IT domain needs a collabrative teamwork where each individual has equal importance and is vital to the project execution and implementation. Therefore, team spirit, collabrative nature are prerequisite for the job. The pace of the project selection and execution is so much that one should be able to adapt and transform him vis-a-vis the changing surroundings. A faster response time is envisaged from individuals. At the same time one should adhere to quality standards. Analytical bent of mind Aptitude for problem solving Comprehensive communication ability, both written and oral Negotiation skills Team spirit Collaborative nature Quality conscious Hardware have additional responsibilities of not only softwares and programmes work but also make computers efficient, faster and network-oriented for better transfer of data. For a successful career in hardware should Be trained and certified to work on leading Operating Systems, like UNIX, Windows 2000, etc. Be eager to know and adopt different networking patterns. Have refined interpersonal skills. Be able to handle emergencies and unexpected situations clamly and efficiently. Courses:The domain of computers and Information Technology is so vast that it is not possible for an individual to have an indepth knowledge of all such domains. It is for this purpose that computer education is broadly divided into two streams : (i) Software (ii) Hardware India is one of the leading gaints in software development. At the same time, in recent times, it is also becoming one of the international hubs in hardware too. A number of courses are available across different universities and institutions in both the domains. Courses vary from short-term certificate course to long-term degree and post-degree courses. The short-term courses are usually of three months to one year duration and they help in the basic understanding of the computer fundamentals. Courses specialised in some particular programming language or some particular domain of computers are also offered by various institutions. Most of the courses are job-oriented and are recognised by the Industry but not by Government or AICTE. (All India Council of Technical Education). The course offered by universities and Government institutions such as C-DAC are recognised not only by the industry but also by Government bodies for the purpose of sutiable public jobs. Long-term professional courses like B.Tech. course is of four years duration; MCA of three years and PGDCA (Post Graduate Diploma in Computer Applications) is of one year duration. Eligibility :The minimum eligibility for courses vary from course to course. For short-term certificate course the minimum eligibility is 10 +2 with Mathematics at least in Standard 10. For Diploma courses of six months to one-year duration you should be either graduate or pursuing graduation course. Long term Diploma course like Post-graduate Diplomas or Advanced Diploma courses require Graduates in any discipline. For PGDCA or MCA one needs to be graduate apart from qualifying the entrance test. For M.Tech. one should be either B.Tech or MCA from recognised institution or university. One also needs to clear entrance test and or have a valid GATE score. Spheres of Study :Computer Technology is such a vast field that an individual can hardly understand or master all such technologies. Therefore, they are divided into many different subfields and domains. Web Technologies :In the application developement two web technologies lead the field. They are Java/J2EE and Microsoft. NET technologies. The Java has been in existence for ten years. And since then it has become more popular. It has remained one of the topmost web technologies. The ease of development and fast runaround time have made. NET very popular. Afterthe release of Windows Longhorn in 2006-07, .NET is set to gather further momentum. Scripting Languages : In programming domain scripting languages play a very important role. A number of scripting languages capable enough to scale down the traditional programming languages. Some of the scripting languages like Linux, Apache, MySQL, Pearl/PHP/Python, LAMP are getting more popular and as a result more number of vacancies are opening up. | dr |
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