It’s shocking, but it’s true: Being a woman who’s more than 20 pounds overweight may actually hike your risk of getting poor medical treatment. In fact, weighing too much can have surprising — and devastating — health repercussions beyond the usual diabetes and heart-health concerns you’ve heard about for years.

Recent studies have found, if you are an overweight woman you:

• May have a harder time getting health insurance or have to pay higher premiums

• Are at higher risk of being misdiagnosed or receiving inaccurate dosages of drugs

• Are less likely to find a fertility doctor who will help you get pregnant

• Are less likely to have cancer detected early and get effective treatment for it What’s going on here?

Fat discrimination is part of the problem. A recent Yale study suggested that weight bias can start when a woman is as little as 13 pounds over her highest healthy weight. Our culture has enormous negativity toward overweight people, and doctors aren’t immune. –Dr. Jerome Groopman, Harvard Medical School professor and author “Our culture has enormous negativity toward overweight people, and doctors aren’t immune,” says Harvard Medical School professor Dr. Jerome Groopman, M.D., author of “How Doctors Think.” “If doctors have negative feelings toward patients, they’re more dismissive, they’re less patient, and it can cloud their judgment, making them prone to diagnostic errors.

” With nearly 70 million American women who are considered overweight, the implications of this new information is disturbing, to say the least. Here, what you need to know to get the top-quality health care you deserve — no matter what you weigh. When Jen Seelaus, from Danbury, Connecticut, went to her doc’s office because she was wheezing, she expected to get her asthma medication tweaked. Instead, she was told she’d feel better if she’d just lose some weight. “I didn’t go to be lectured about my weight. I was there because I couldn’t breathe,” says the 5-foot-3, 195-pound woman. “Asthma can be dangerous if it gets out of control, and the nurse practitioner totally ignored that because of my weight.” Health.com: 25 diet-busting foods you should never eat Seelaus’s nurse made a classic diagnostic error, according to Groopman.

“It’s called attribution, because your thinking is colored by a stereotype and you attribute the entire clinical picture to that stereo­type. Because obesity can cause so many health problems, it’s very easy to blame a variety of complaints, from knee pain to breathing troubles, on a patient’s weight. That’s why doctors — and patients — need to constantly ask, ‘What else could this be?’ ”

There aren’t statistics on how many diagnostic errors are due to weight, but the data for the general population is disturbing enough.

“Doctors make mistakes in diagnosing 10 to 15 percent of all patients, and in half of those cases it causes real harm,” Groopman says. Based on anecdotal evidence — patients who’ve told her that their doctors are often too quick to blame symptoms on weight — Rebecca Puhl, Ph.D., director of Research and Weight Stigma Initiatives at the Rudd Center for Food Policy and Obesity at Yale University, suspects that being heavy could further increase the odds of being misdiagnosed.

Health.com: 50 ways to cut 500 calories a day Even if doctors are aware of the potential traps they can fall into when diagnosing an overweight patient, extra body fat can literally obscure some illnesses, including heart disease and different types of cancer.

“It’s more difficult to hear heart and lung sounds in heavy people,” says Dr. Mary Margaret Huizinga, M.D., M.P.H., director of the Johns Hopkins Digestive Weight Loss Center. “I use an electronic stethoscope, which works well, but I’m very aware of the issues that can crop up in overweight patients. Not all doctors have these stethoscopes — or are aware they need one.

” Dr. Jeffrey C. King, M.D., professor and director of maternal-and-fetal medicine at the University of Louisville School of Medicine, says that “the more tissue between the palpating hand and what you’re trying to feel, the harder it is to detect a mass.” That may be what happened to Karen Tang [not her real name], a 5-foot-8, 280-pound woman who went to the doctor for pelvic pain. Her doctor palpated her uterus but didn’t feel anything. “By the time I was referred to a gynecologist, I had a fibroid the size of a melon — so large it was putting pressure on my bladder,” she recalls. Even a routine pelvic exam can be tricky, especially if you’ve had children.

“The vaginal walls become lax and collapse into the middle, obscuring the cervix,” King says. Larger or modified speculums can help, but not all docs have them and they can make the exam more uncomfortable, says Dr. Lynda Wolf, M.D., a reproductive endocrinologist at Reproductive Medicine Associates of Michigan.

Health.com: 20 meals that won’t kill your cholesterol That may explain the disturbing finding that obese women are less likely to get Pap smears than normal-weight women. But doctors may be partly to blame for the screening lapse, too. A University of Connecticut study of more than 1,300 physicians found that 17 percent were reluctant to do pelvic exams on obese women and that 83 percent were hesitant if the patient herself seemed reluctant.

 Why diagnostic tests are difficult Ultrasound is the approach that’s the most limited by body fat, because the beams can’t penetrate the tissue if you have more than 8 centimeters of subcutaneous fat. –Dr. Raul Uppot, radiologist Physical exams aren’t the only things hampered by obesity. Large patients may not fit into diagnostic scanning machines — computed tomography (CT) and magnetic resonance imaging (MRI), for instance — and X-rays and ultrasounds may not be as effective, says Dr. Raul N. Uppot, M.D., a radiologist in the Division of Abdominal Imaging and Intervention at Massachusetts General Hospital in Boston.

“Ultrasound is the approach that’s the most limited by body fat, because the beams can’t penetrate the tissue if you have more than 8 centimeters of subcutaneous fat,” he says. This affects women, in particular, because ultrasound is used to diagnose uterine tumors and ovarian cysts and to evaluate the mother’s and baby’s health during pregnancy. Just last May, researchers at the University of Texas Southwestern Medical Center at Dallas reported a 20 percent decrease in the ability to detect problems in fetuses of obese women with ultrasound. In another study, obese women were 20 percent more likely to have false-positive results from mammograms — readings that can lead to unnecessary biopsies and anxiety.

While CT scans are less affected by body fat, getting clear images in heavy patients typically requires a lot more radiation than with normal-weight patients, making it riskier, especially if numerous CT scans are required. But trying to diagnose a health problem without proper imaging is like driving blindfolded. Doctors are sometimes left with little to go on except symptoms and intuition, especially in the emergency room, where physicians make life-and-death decisions in minutes.

“If we can’t get the imaging because of a patient’s weight, and we are concerned about a pulmonary embolism or appendicitis, for example, we have to go ahead and treat based on our clinical impression,” says Dr. Archana Reddy, M.D., a Chicago-area ER physician. Being overweight can get in the way of effective cancer treatment, too, experts say. The problem: underdosing. “Oncologists usually base chemo on patients’ ideal weight rather than their true weight, partly because chemo is so toxic and partly because drug trials typically include only average women, so we don’t know the correct dose for bigger women,” says Dr. Kellie Schneider, M.D., a gynecologic oncologist at the University of Alabama at Birmingham. “But underdosing can mean the difference between life and death.”

Health.com: America’s top 10 healthiest diets Doctors have long known that obese women are more likely to die of ovarian and breast cancers, but when Schneider and her colleagues recently gave a group of overweight ovarian cancer patients chemotherapy based on their actual weights, they found that the women were as likely to survive the illness as thinner patients. “Doctors aren’t intentionally under-treating overweight women,” Schneider says. “We’re just working with limited information.” Why heavy patients can’t find help There are no studies on how often doctors refuse to treat patients because of their weight. But Sondra Solovay, an Oakland, California, attorney and author of Tipping the Scales of Justice: Fighting Weight-Based Discrimination, says she hears enough anecdotes to believe it’s commonplace.

Because of recent studies about various complications, Dr. A.J. Yates Jr., M.D., associate professor in the Department of Orthopaedic Surgery at the University of Pittsburgh Medical Center, says there are legitimate concerns about operating on patients with a very high body mass index (BMI). But Yates also notes that some surgeons are reluctant to offer surgery to very overweight patients because the operations are more difficult and time-consuming. And because data on surgical-complication rates is often calculated without accounting for the higher risk of an obese patient, even a few patients with complications can make the surgeon or hospital look bad to insurance companies. “If hospitals feel they’re not looking good they could put subtle pressure on surgeons to avoid risky patients,” Yates says. His concern is that overweight people could be increasingly discriminated against because of this.

Health.com: How to quit smoking without gaining weight Suzy Smith, a 5-foot-3, 400-pound woman from Colonial Beach, Virginia, believes she was one of those people. When her doctor found a large tumor on her kidney, she struggled to find a surgeon who would treat her. Her urologist said that the hospital where he practiced didn’t have a table sturdy enough to hold her, and he referred her to a surgeon several hours away. I was so shocked. He was basically telling me he wouldn’t do the thing that was the most likely to save my life. –

Suzy Smith, kidney cancer patient RELATED TOPICS Obesity Infertility Cancer “As soon as that doctor walked in the room, I could tell something was wrong by the look on his face,” she says. “He told me he wouldn’t operate. He wouldn’t risk it,” she says. Instead, he offered her cryoablation — a technique that freezes and removes tissue but is less effective than surgery for large tumors. “I was so shocked,” Smith says. “He was basically telling me he wouldn’t do the thing that was the most likely to save my life.” Finally, in early-December 2008 a doctor removed the tumor. The surgery, after all the preceding drama, was anticlimactic. “It went fantastically well,” Smith says. “My doctors were really pleased.” But the overall experience, she says, was degrading and disheartening. “Here I was trying to deal with a diagnosis of cancer, worrying that the cancer might spread with every day that went by, and the medical field was closing doors on me left and right.”

reference: http://www.cnn.com/2010/HEALTH/01/21/obesity.discrimination/index.html

 

         

From the composition of just two human genomes, geneticists have computed the size of the human population 1.2 million years ago from which everyone in the world is descended.

They put the number at 18,500 people, but this refers only to breeding individuals, the “effective” population. The actual population would have been about three times as large, or 55,500.

Comparable estimates for other primates then are 21,000 for chimpanzees and 25,000 for gorillas. In biological terms, it seems, humans were not a very successful species, and the strategy of investing in larger brains than those of their fellow apes had not yet produced any big payoff. Human population numbers did not reach high levels until after the advent of agriculture.

Geneticists have long known that the ancestors of modern humans numbered as few as 10,000 at some time in the last 100,000 years. The critically low number suggested that some catastrophe, like disease or climate change induced by a volcano, had brought humans close to the brink of extinction.

If the new estimate is correct, however, human population size has been small and fairly constant throughout most of the last million years, ruling out the need to look for a catastrophe.

The estimate, reported in the issue on Tuesday of The Proceedings of the National Academy of Sciences, was made by a team of population geneticists at the University of Utah led by Chad D. Huff and Lynn B. Jorde.

The human population a million years ago was represented by archaic species like Homo ergaster in Africa and Homo erectus in East Asia. The Utah team says its estimate of 18,500 implies “an unusually small population for a species spread across the entire Old World.”

But that estimate would apply to the worldwide population only if there were inbreeding between the humans on the different continents. If not, and if modern humans are descended from just one of these populations, like Homo ergaster in Africa, then the estimate would apply only to that.

Richard G. Klein, a paleoanthropologist at Stanford, said it was hard to believe the population from which modern humans are descended was as small as 18,500 “unless they were geographically restricted to Africa or a small part of it.”

There is no independent way of assessing a genetics-based estimate of population size at this period, Dr. Klein said, although archaeologists have developed ways of assessing ancient populations of more recent times.

The Utah team based its estimate on the genetic variation present in two complete human genomes, one prepared by the government’s human genome project and the other by J. Craig Venter, the genome sequencing pioneer. The government decoded a single copy of a mosaic genome derived from a medley of people, apparently of European and Asian origin. Dr. Venter decoded both copies of his own genome, the one inherited from his father and the one from his mother.

The Utah team thus had three genomes to work with and looked at ancient elements known as Alu insertions, the youngest class of which appeared in the human genome around a million years ago. The amount of variation seen in the DNA immediately surrounding the Alu insertions gave a measure of the size of human population at that time.

Their estimate agrees almost exactly with an earlier one, also based on Alu insertions but with sparser data. The insertions tag ancient regions of the genome that are unaffected by the recent growth in population, Dr. Huff said.

REFERENCE: http://www.nytimes.com/2010/01/19/science/19human.html?ref=health

A version of this article appeared in print on January 19, 2010, on page D4 of the New York edition.

But there is another factor. In some cases, women are being found to have oral cancer caused by HPV, or the human papillomavirus (version 16). Different versions of HPV are present in most cases of cervical cancer. Like cervical cancer, in oral cancer cases, the virus is transferred through sexual activity.

Based on recent data, the Oral Cancer Foundation believes in people under the age of 50, HPV may even be replacing tobacco as the primary cause of the spread of oral cancer.

Folsom was shocked when she heard her cancer contained HPV cells.

“I said, ‘What? How is that possible?’ ” she exclaimed. “But doctors told me that it might have been caused by something I did, years and years ago. It could actually show up later and cause the cancer.”

MayoClinic.com: Mouth cancer

HPV causes irregular cells to multiply, The virus thrives in a moist, dark environment, said Dr. Youssef Obeid, a prosthodontist and director of Obeid Dental in Bethesda, Maryland. Prosthodontists specialize in tooth replacement, jaw restructuring, disease and injuries to the mouth. “The mouth is a perfect place for it to grow.” By transferring the virus during oral sex, it stays in the mouth and causes lesions. Many eventually turn cancerous. “It’s something we are very much aware of and look for, especially in women,” he said.

Folsom was lucky. Her dentist caught the cancer before it spread, a fact that Folsom attributes to her biannual checkups. When found early, oral cancer patients have an 80 to 90 percent survival rate. A good dentist will look for possible signs of oral cancer by checking the cheeks, the tongue, the tonsils and the larynx for possible lesions, says the American Dental Association.

“That’s why we ask the patients simple things, to move your tongue, move it sideways, stick your tongue out, say ahhh,” Obeid said. ‘”We want to get a good view of the mouth.”

MayoClinic.com: HPV infection

Since Folsom’s cancer was diagnosed in March 2008, she’s undergone surgery and has had about four months of radiation. She is still in rehabilitation to help her chew and open her mouth wider. She uses a mouth exerciser that helps her stretch the muscles that were affected by her operation. She also went through rehab when she broke her collarbone after her radiation treatments, because her bones had become so brittle. “It just snapped one day,” she said with a shrug. “That’s part of the side effects from the radiation. It affects your bones.”

Her other side effects are minor. She constantly has dry mouth and carries water with her everywhere. She avoids anything spicy or acidic, because it can sting the area where the cancer was removed. She lost almost 50 pounds after the surgery because she couldn’t eat. In some ways she considers the weight loss a good thing because it also reduced her high blood pressure and she was able to drop that medication. “For everything, there is a blessing,” she said.

Although Folsom is cancer free now, she said she is considering enrolling in a trial that uses a form of the HPV vaccine to prevent patient’s oral cancer from recurring.

MayoClinic.com: Chewing tobacco: Not a safe alternative to cigarettes.

“It’s been a long road to recovery. But I am very fortunate. I’ve had great treatment and great care,” she said. “But the most important thing is I want women to be aware of oral cancer and make sure they don’t ignore a sore in their mouth, or pain. It could be something,” Folsom said. “And it needs to be checked out. That checkup can save your life.”

Reference:http://www.cnn.com/2009/HEALTH/11/30/oral.cancer.women/index.html

The Cat Ba leopard gecko is found exclusively in Cat Ba Island National Park in northern Vietnam.

The discovery of 100 new plants, 28 fish, 18 reptiles, 14 amphibians, two mammals and one bird species highlights the extent of the biodiversity in the region, said Barney Long, head of the WWF’s Asian Species Conservation program.

“It’s a melting pot of diverse habitats. It has some of the wettest forests on the planet, high mountains, and a diverse array of terrestrial and marine habitats, including the Mekong River,” he said.

“We continue to find new species of fish, primates and mammals, and nowhere else compares to the amount of large mammals that have been discovered in the region. It shows how little we know about species in the region,” he said. “From a biodiversity perspective, there are still huge amounts to discover about region.”

The Greater Mekong consists of the countries through which the Mekong River flows: Cambodia, Laos, Myanmar, Thailand, Vietnam and Yunnan Province of China.

With 16 global ecoregions — areas defined by their shared ecological features and animal communities — the Greater Mekong has more protected spaces than anywhere else on mainland Asia, according to the WWF.

The colorful Cat Ba leopard gecko of northern Vietnam has large, orange-brown “catlike eyes” and a body of leopard stripes, according to a report released Friday.

Its name refers to its place of origin, Cat Ba Island, the largest of 366 islands in Cat Ba Archipelago and home to many rare species that can only be found on the island. Scientists believe the high number of species unique to the island might be due to the long separation of the island from continental Vietnam, the report says.

Limnonectes megastomias — a fanged frog with an appetite for other frogs, insects and birds — has only been found in three remote areas of medium-to-high altitudes in eastern Thailand.

Globally, new species of mammals are rare finds, but in 2008 alone, new species of the mouselike musk shrew and a tube-nosed bat emerged from the region.

War and political unrest have kept large parts of the region, particularly Vietnam, Laos and Myanmar, off-limits to scientific exploration up until the past two decades, Long said.

Since 1997, nearly 1,200 new species have been discovered, many that cannot be found anywhere else, said Dekila Chungyalpa, director of WWF’s Greater Mekong Program.

But the rapid pace of development in the Mekong region, coupled with the effects of climate change, are threatening to drive the species into extinction, Chungyalpa said.

“As we become familiar with more species in the region, our understanding of climate change and how it impacts these new species is changing,” she said.

Chungyalpa said conservative estimates by the WWF project a 1-meter rise in sea level on the delta’s coastline over the next decade, which will affect not only marine life, but also people who rely on the delta as a source of sustenance and employment, she said.

In 2007, the United Nations Intergovernmental Panel on Climate Change released its Fourth Assessment Report, which projected that global sea levels could rise from 18 to 59 centimeters (7 to 23 inches) over the next century based on six possible scenarios.

Already, Chungyalpa said, the area has been affected by an increase in tropical storms off the coast, which brings in more seawater and changes the flooding patterns in the delta. Some researchers, however, have questioned the link between climate change and more intense tropical storms. Apart from climate change, construction of dams and hydropower plants along the delta could further disrupt its waters, potentially displacing millions, destroying sources of drinkable water and disrupting the production of rice, Chungyalpa said.

“The delta is the rice bowl of the region. What will happen to people who depend on it if it’s no longer there?” she said.

The WWF says it supports the idea of an agreement among the Mekong countries on how to respond to infrastructure development and climate change in terms of protecting its natural resources and people.

“Climate change is making it obvious that we can’t treat development like it’s a separate issue,” she said. “We need to be addressing this issue now. It’s such an immediate issue for us and it’s going to change everything in this region if we don’t address it.”

REFERENCE:http://edition.cnn.com/2009/TECH/science/09/26/mekong.species/index.html

The oldest-known hominid skeleton was a 4-foot-tall female who walked upright more than 4 million years ago and offers new clues to how humans may have evolved, scientists say.

This sketch shows what a 4 million-year-old hominid, nicknamed Ardi, may have looked like.

Scientists believe that the fossilized remains, which were discovered in 1994 in Ethiopia and studied for years by an international team of researchers, support beliefs that humans and chimpanzees evolved separately from a common ancestor.

“This is not an ordinary fossil. It’s not a chimp. It’s not a human. It shows us what we used to be,” said project co-director Tim White, a paleontologist at the University of California, Berkeley.

Ardipithecus ramidus, nicknamed “Ardi,” is a hominid species that lived 4.4 million years ago in what is now Aramis, Ethiopia. That makes Ardi more than a million years older than the celebrated Lucy, the partial ape-human skeleton found in Africa in 1974.

Ardi’s 125-piece skeleton includes the skull, teeth, pelvis, hands and feet bones. Scientists say the data collected from Ardi’s bone fragments over the past 17 years push back the story of human evolution further than previously believed.

“In fact, what Ardipithecus tells us is that we as humans have been evolving to what we are today for at least 6 million years,” C. Owen Lovejoy, an evolutionary biologist at Kent State University and project anatomist, said Thursday.

Analysis of Ardi’s skeleton reveals that she weighed about 110 pounds, had very long arms and fingers, and possessed an opposable big toe that would have helped her grasp branches while moving through trees.

Ardi’s brain was believed to be the size of a chimp’s, but she also had many human-like features, such as the ability to walk upright on two legs. Her “all-purpose type” teeth indicate that she probably ate a combination of plants, fruits and small mammals, scientists say.

“The anatomy behind this behavioral combination is very unexpected and is certain to cause considerable rethinking of not only our evolutionary past, but also that of our living relatives: the great apes,” said Alan Walker, professor of biological anthropology at Pennsylvania State University.

Many scientists hypothesize that humans took a different evolutionary trajectory from those of chimpanzees, bonobos and gorillas. Ardi’s findings help challenge earlier beliefs that humans evolved from chimpanzees, their closest genetic relatives, scientists say.

Researchers are still trying to pinpoint when the two lineages — chimps and humans — split from their common ancestor.

Digging up the past has not been easy.

Scientists stumbled upon the Ardipithecus fossil in 1994 when a graduate student found a single upper molar tooth. The rest of Ardi’s fossilized bones, sandwiched between layers of volcanic rock, took three years to be recovered and many more to be analyzed.

“In many ways, the discovery of Ardipithecus has been like a marathon,” White said.

“Ardipithecus ramidus and its prevailing anatomy revolutionize the way most of us understood the earlier part of our evolutionary history,” said team member Yohannes Haile-Selassie, paleontologist at the Cleveland Museum of Natural History.

The Ardi findings are the work of 47 paleontologists and geologists representing 10 countries. The results will be published Friday in 11 articles in a special edition of the journal Science.

Until now, Australopithecus, nicknamed “Lucy,” was the oldest fossil studied by scientists seeking to explain human evolution. Lucy is believed to have lived about 3.2 million years ago in what is now Ethiopia.

Many scientists credit Ethiopia with taking the lead in helping the world better understand the origins of humans.

“This finding points to a deeper sense of our [humans'] interconnectedness,” Samuel Assefa, Ethiopian ambassador to the United States, said Thursday. “We are all Ethiopians at heart.”

Ardi’s skeleton resides in the National Museum of Ethiopia in Addis Ababa.

 REFERENCE:http://edition.cnn.com/2009/TECH/science/10/01/oldest.human.skeleton/index.html

Wave motion

     Waves

 A wave is an organized traveling disturbance in medium, such as air. The medium itself dose not flow because of the wave; rather, a disturbance in the medium travels through the medium. Waves transmit energy without transmitting matter.

 A mechanical wave is a disturbance which is created by a vibrating object and subsequently travels through a medium from one location to another, transporting energy as it moves. The mechanism by which a mechanical wave propagates itself through a medium involves particle interaction; one particle applies a push or pull on its adjacent neighbor, causing a displacement of that neighbor from the equilibrium or rest position. As a wave is observed traveling through a medium, a crest is seen moving along from particle to particle.

  Sine Waves

    Sine and Sinusoid

 Music from Fractal Music:

There are many interesting connections between music and mathematics, though these are rarely used when teaching mathematics in school. In this section we will see one example which involves using musical motivations to introduce some mathematical ideas. The aim is to develop a random method for making music which produces pleasant results.

 Random Music:

This activity should start with some discussion and brainstorming about how music could be created randomly and kind of properties that such music should have. There may also be some discussion about how mathematics might help in this work. We will describe three methods for creating music. Each is based on some kind of noise, a random process in time.

   Standing and Travelling Waves

 A crest is seen to move or progress a cross a medium.

This crest is followed by a trough which is in turn followed by the next crest. In fact, one would observe a distinct wave pattern (in the form of a sine wave) traveling through the medium. This sine wave pattern continues to move in uninterrupted fashion until it encounters another wave along the medium or until it encounters a boundary with another medium. This type of wave pattern which is seen traveling through a medium is sometimes referred to as a traveling wave.

Traveling waves are observed when a wave is not confined to a given space along the medium. The most commonly observed traveling wave is an ocean wave. If a wave is introduced into an elastic cord with its ends held 3 meters apart, it becomes confined in a small region. Such a wave has only 3 meters along which to travel. The wave will quickly reach the end of the cord, reflect and travel back in the opposite direction. Any reflected portion of the wave will then interfere with the portion of the wave incident towards the fixed end.

This interference produces a new shape in the medium which seldom resembles the shape of a sine wave. Subsequently, a traveling wave (a repeating pattern which is observed to move through a medium in uninterrupted fashion) is not observed in the cord. Indeed there are traveling waves in the cord, it is just that they are not easily detectable because of their interference with each other. In such instances, rather than observing the pure shape of a sine wave pattern, a rather irregular and non-repeating pattern is produced in the cord which tends to change appearance over time. This irregular looking shape is the result of the interference of an incident sine wave pattern with a reflected sine wave pattern in a rather non-sequenced and untimely manner. Both the incident and reflected wave patterns continue their motion through the medium, meeting up with one another at different locations in different ways. For example, the middle of the cord might experience a crest meeting a half crest; then moments later, a crest meeting a quarter trough; then moments later, a three-quarters crest meeting a one-fifth trough, etc. This interference leads to a very irregular and non-repeating motion of the medium. The appearance of an actual wave pattern is difficult to detect amidst the irregular motions of the individual particles.

It is however possible to have a wave confined to a given space in a medium and still produces a regular wave pattern which is readily discernible amidst the motion of the medium. For instance, if an elastic rope is held end to end and vibrated at just the right frequency, a wave pattern would be produced which assumes the shape of a sine wave and is seen to change over time. The wave pattern is only produced when one end of the rope is vibrated at just the right frequency. When the proper frequency is used, the interference of the incident wave and the reflected wave occur in such a manner that there are specific points along the medium which appear to be standing still. Because the observed wave pattern is characterized by points which appear to be standing still, the pattern is often called a standing wave pattern. There are other points along the medium whose displacement changes over time, but in a regular manner. These points vibrate back and forth from a positive displacement to a negative displacement; the vibrations occur at regular time intervals such that the motion of the medium is regular and repeating. A pattern is readily observable.

The diagram at the right depicts a standing wave pattern in a medium. A snapshot of the medium over time is depicted using various colors. Note that point A on the medium moves from a maximum positive to a maximum negative displacement over time. The diagram only shows one-half cycle of the motion of the standing wave pattern. The motion would continue and persist, with point A returning to the same maximum positive displacement and then continuing its back-and-forth vibration between the up to the down position. Note that point B on the medium is a point which never moves. Point B is a point of no displacement.

Vibration of standing wave.

The modes of vibration associated with resonance in extended objects like strings and air columns have characteristic patterns called standing waves. These standing wave modes arise from the combination of reflection and interference such that the reflected waves interfere constructively with the incident waves. An important part of the condition for this constructive interference for stretched strings is the fact that the waves change phase upon reflection from a fixed end. Under these conditions, the medium appears to vibrate in segments or regions and the fact that these vibrations are made up of traveling waves is not apparent – hence the term “standing wave”.

Standing wave. 

The behavior of the waves at the points of minimum and maximum vibrations (nodes and antinodes) contributes to the constructive interference which forms the resonant standing waves. Standing waves in air columns also form nodes and antinodes, but the phase changes involved must be separately examined for the case of air columns.

 The resonant standing waves.

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• G. W. Wornell and A. V. Oppenheim. Estimation of fractal signals from noisy measurements using wavelets. IEEE Trans. On Signal Processing, March 1992.
• Shahrokh David Yadegari. Using self-similarity for sound/music synthesis. Proceedings of 1991 International Computer Music Conference, 1991.
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 I WANT TO EXPRESS MY THANKS FOR  TO  MISS   MİNE  SARIDAĞ  FROM  DEPARTMENT OF MATHEMATICS  YEDİTEPE UNIVERSITY  HER EXPERTISE AND KINDNESS IN HANDLING EVERYTHING WAS  INVALUABLE  AND  ADVISER  PROF. DR. AVADİS HACINLIYAN…

          Scientists have been studying the power of smells for many years. They have learned that more than any of our other four senses , our sense of smell can change our mood and help us remember things. For example , if you are told to think  about popcorn , you would probably remember its smell. And then you might remember a movie  you saw while eating  it . Our sense of smell warns us of fire. And smells can make you feel hungry , from just one whiff of food.

                               The Power Of  Smell

         Because  the sense of smell is so powerful , store owners use smells to sell products . Businesses spend thousands of dollars to scent their stores. They hope the odors will get people inside the store and put them in the mood to buy.They also hope the smell will help customers remember the store later, so they will come back again. Suppose you re  in a grocery store looking for your favorite kind of cereal to buy. Suddenly ,you smell chocolate chip cookies. They smell scrumptious.You forget all about buying cereal and go to the bakery section. Guess what! you were  being led by nose. You walked into a trap -an odor trap! The smell was fake . The odor was cooked up by scientists in a lab. Then, it was spread by the store’s owners to entice you to come to the bakery section.

        Using smells to sell products isnt new. In 1966 , one company added the smell of lemon to its  dish detergent. They wanted people to think the soap contained ”natural” cleaners. It worked!

                                              Spreading  Smells

       Store desinger J’ Amy Owens uses ”fragrance planning” as part of her store design. She believes each store should have its own special smell. For example , for a children’s clothing store , Owens used the smell of cinnamon and apples. She hopes shoppers will think the children’s  clothes are as American as apple pie. Owens spreads the store scents secretly. She soaks little balls in fragrance and  hides them in light fixtures and heating pipes. She also puts some in a small heater to warm up the fragrance. A fan in the heater spreads the smell throughout the store. Sometimes she uses computer-controllled machines to spread the smell. However , getting the right amount of odor in the air  can be tricky. When one store owner first started using peach fragrance  in his store , the whole store ended up smelling like a peach farm.

                                              Is  There  Proof?

        Do the smells really work? Dr. Alan Hirsch is an expert on smell. He thinks using smells works. Hirsch says that it doesnt take a lot of  smell to affect you. Store owners can lure you to the candy aisle-even if you dont realize you re smelling candy. Dr. Hirsch has done some interesting  experiments to test the effects of smell on customers. In one experiment , he took thirty-one people to a sneaker store that smelled slightly like flowers. Later , he took another group of volunteers  to the same store , but with no flower odor. Dr. Hirsch found that 84 percent of the shoppers were more likely  to buy sneakers when the store was scented. He also found that it didnt matter if the people liked the smell or not.

     ”Whether the volunteers  liked the flower scent or not didnt matter,” Hirsch says. 

    ”Some reported that they  hated the smell. However,  they still were more likely to buy the shoes in scented room.”

    That’s pretty good proof  that smells influence purchasing behaviour.

     A  sign of health…or a sign of wealth?

 Build:Nowadays, a woman who wants to make a career in the world of fashion has to watch her weight.However,during most of our history,being plump was considered more attractive for women:it showed that they didnt have to work and could afford  good food.However, the story is a little different for men.In Greek or Roman society,people thought that a muscular physique was the most attractive symbol of masculinity and this idea has continued through the centuries with a few small changes.For example, in the Middle Ages,men wore tights or stockings so it was fashionable to have muscular legs and thighs.Today,in the age of the T-shirt,men worry more about arm and chest muscles.It is still fashionable for men to look fit as it suggests you take your health seriously.

Hair:Queen Elizabeth The First  started going bald at an early age.She started a fashion for wigs in England.The fashion spread and eventually wigs were popular with both sexes for the next three hundred years.Wigs became a status symbol-the bigger the wig ,the more important  you were. However, there was another reason that wigs were an advantage. In those days ,even rich people rarely washed and the unhygienic conditions attracted fleas and other pests. Shaving off your hair and wearing a wig was often the only answer.People used animal fat to keep the wigs in place- the smell must have been terrible!            

Skin:  During the Renaissance in Europe  it was unfashionable to have a dark complexion because it was  a sign that you worked  outside. Because of this , men and women did everything they could to keep their skin pale-often women used dangerous chemicals to paint their faces, which sometimes resulted in a painful death. This did not change until the 1920 s when Coco Chanel, a famous fashion designer,accidentally fell asleep in the sun. The suntan was born and remained popular for the rest of the 20th century-an easy way to show that  you were rich enough to spend your holidays in exotic, sunny places.     

The showerheads, which work by pressure of water and don’t need battery or electricity, changes their color via heat of water.

Owing to sensors which are on the edges of the sticks, the sticks are opening that you can pass. These are really good at heat isolation.

Lustration faucet with photocell gives water for 10 seconds when you every show your hands. It provides maximum hygiene and water saving.

         Hygiene is the problem of our era. Therefore, the “use and throw products” are so suitable nowadays. One of them is a herbal soap which is 18 meter long. Crop 3-4 cm and use it. That’s easy..!

An invention that is candidate to be helpful for housewifes…! We hope that taste of meals increases. You can see the weight of the material that you cut on the chopping board.

While the beautiful lady is breathing, the vane is producing electricity by turning around and the led is lightening by the intensity of electricity.