One of the Internet's most comprehensive lists of foods with their glycemic index. We all know that milk is a great source of calcium, but you may be surprised by all the different foods you can work into your diet to reach your daily recommended amount of calcium. The best options are to the left. While the glycemic index calculates the relative blood sugar rise induced by given foods, the insulin index evaluates the insulin response generated by 38 different foods. Results: Among the … Whenever you eat foods that provokes a substantial insulin release from your pancreas, your body is signaled to build either fat, muscle or both. One high-protein, low-carb website, emphasizes that carbohydrates are the "root of all evil" when it comes to weight loss and health. Andrews and McMeel, 1997. Half your plate should be vegetables and fruits each meal. The glycemic index , or GI index is the measurement of how foods raise our blood glucose after eating them. Continue reading >>, Reader Pete asked for some thoughts on the “Insulin Index,” a measurement chart similar to the glycemic index. We had to wait until 2011 for the index to grow to about 120 foods in “Prediction of postprandial glycemia and insulinemia in lean, young, healthy adults.” I reviewed that study here at “Manage Your Blood Sugar Better with the Insulin Index.” Now, a much more extensive study of the food insulin index is available, and it is further expanded to include 26 more tested foods. They also conclude that insulin indices may be useful for dietary management and avoidance of non-insulin-dependent diabetes mellitus and hyperlipidemia. The research on the insulin index of foods is intriguing but limited. Or maybe someone told you that you have to give up all your f... D.D. 172. His system became known as the glycemic index (GI). The Insulin Index can be more useful than either the Glycemic Index or the Glycemic Load because certain foods (e.g., lean meats and proteins) cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load. This website was created by a kidney stone patient to make oxalate content data more easily accessible and searchable. Carb Counting Doesn’t Help One of the most significant findings to come out of Bell’s work is that carbohydrate counting simply doesn’t work well enough. bananas, potatoes) Protein rich foods are the second most insulinogenic (i.e. Plummeting blood glucose levels due to the mega doses of insulin don’t feel good either. By comparison, 244 peer-reviewed articles mention the glycemic index. 2. The good carbs on the list of carbohydrate foods can provide your body with energy, optimum nutrition, proper brain and organ function and a healthy, attractive appearance. Try to avoid or limit these foods as much as possible: refined carbohydrates, such as white bread and pastries. 100% whole grain breads* - The more whole grains and seeds in the bread the lower the index. Relative effectiveness of insulin pump treatment over multiple daily injections and structured education during flexible intensive insulin treatment for type 1 diabetes: cluster randomised trial (REPOSE), How to Eat a Low Glycemic, Plant-Based Diet. Insulinogenic Effects of Milk- and Other Dietary Proteins, Mechanisms and metabolic implications Nilsson, Mikael LU () . Should I be concerned about that omelet I ate for breakfast? Then in early 2014, I came across Jason Fung’s Aetiology of Obesity series on YouTube where he discussed the food insulin index research that had been carried out at the University of Sydney which seemed to provide more insight into our insulin response to food. The Insulin Index can be more useful than either the Glycemic Index or the Glycemic Load because certain foods (e.g., lean meats and proteins) cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load. To evaluate early-phase insulin metabolism, we calculated the insulinogenic index after 15 (II 15 min) and 30 min. Two tbsp. The complete list of the glycemic index and glycemic load for more than 1,000 foods can be found in the article "International tables of glycemic index and glycemic load values: 2008" by Fiona S. Atkinson, Kaye Foster-Powell, and Jennie C. Brand-Miller in the December 2008 issue of Diabetes Care, Vol. Cabbage also ranks a 10 on the GI. Foods raise glucose to varying levels (carbs increase blood sugar the most, fats and protein second). As I pointed out in that post, among insulin’s many roles is that it serves as a pro-storage hormone that promotes the formation of new tissue. English EN. The standardized Glycemic Index ranges from 0 to 100. Bell peppers are available in a rainbow of colors, including red, green, yellow, orange and purple. Foods that cause inflammation. Therefore, high levels of insulin, known as hyperinsulinism, would be expected to promote obesity." First off, let’s remember that the protein-rich foods didn’t result in the physical stress of blood sugar spikes. The lower a food is on the GI, the lower the effect on your blood sugar. "Carbohydrate is not the only stimulus for insulin secretion." foods you eat. Holt et al. How To Use Diet To Maintain Blood Sugar Levels. High blood glucose levels make her feel “yucky”. Understanding the factors that our requirement for insulin is critical to good managing and avoiding diabetes and maintaining good metabolic health. Dietary choices may help people manage their symptoms. A (27 items found) Acorn Squash: Legal: Click on the food items below for more information. butter, bacon) … "In fact meat protein causes as much insulin release as pure sugar." Close. Continue reading >>, The new food insulin index can work much better than carbohydrate counting, which for years has been considered to be the gold standard for improving glycemic control. This low-fat food regimen is designed for women and uses the glycemic index to increase serotonin levels. all canned fruit, jams, jellies containing high fructose corn syrup and other high glycemic additives, most commercial brands peanut butter (use ones that contain only nuts,) soft drinks, box drinks and other commercial fruit drinks, sports drinks, gatorade and fruit juices. ; or beef, chicken, liver etc. of key foods each day, chosen from a list of 16 to 21 key foods per diet and provided free of charge. Insulin is the hormone that regulates blood sugar levels and allows for the absorption of glucose, which provides energy. Just because a food is not on our list doesn't mean we don't think it can be included in a diet geared towards the Healthiest Way of Eating as long as it is a whole, natural, nutrient-rich food. Only 16 peer-reviewed articles in MEDLINE even mention the term "insulin index," and only one of them actually reports the results of food comparisons. … Here Is A List Of 92 Alkaline Foods That Can Fight Cancer, Inflammation, Diabetes and Heart Disease! Sadly, the common eating pattern in North America is to eat insulin producing foods without much foresight, which is part of the reason we battle the bulge. Most other people by and large probably aren’t chowing down on grass-fed lamb leg, roast chicken, sockeye salmon, canned sardines, and whey protein shakes. Legionella Testing Lab - High Quality Lab Results CDC ELITE & NYSDOH ELAP Certified - Fast Results North America Lab Locations Hope that makes sense. The following is a list of foods that are allowed (legal) and foods that are not allowed (illegal) while following the Specific Carbohydrate Diet™, as outlined in the book Breaking the Vicious Cycle. My goal is to create a list of the amount of insulin released from various food groups in general, and within that, the amount of insulin released by each type, ie. Broccoli. Living a diabetic life is a challenge. Search this website Search. Let the printable list of low glycemic foods guide your way of eating. Of course, this comes as less of a surprise.) 254 pages. Lipetz, Philip, and Monika Pichler. Oxalate (oxalic acid) content of 750+ foods with numbers from university and government sources. When most people think of “diabetes,” they think of Type 2 Diabetes – that’s the kind that you (usually) get as ... Metformin is a medicine used to treat type 2 diabetes and sometimes polycystic ovary syndrome (PCOS). (Baked goods, with their high levels of refined carbs, elicited a very high rise in insulin as well. Additional foods: 1. In fact, the GI was such a popular and powerful idea that it spawned an entire series of diet books and programs, books that still can be found in bookstores today. Understanding the GI values of specific foods can help reduce harmful spikes in blood sugar, as sugars and carbohydrates are broken down and your metabolism releases insulin to aid in digestion. Iron is an essential mineral that is a part of hemoglobin which helps maintain your strength and energy. If you are following the GI or South Beach diet you should aim to include more foods with a low glycemic index in your diet. 31, number 12, pages 2281-2283. The Glycemic Index is a commonly used tool for determining the effect of carbohydrate-containing foods on blood glucose levels. The time course for changes in food intake, body weight, plasma glucose and insulin concentrations and HOMA index was monitored over a period of 8 weeks in rats exposed from the 8th week after birth to diets containing either starch or fructose and sunflower oil. A dietitian advised participants how to incorporate the key foods into their diets to avoid weight gain. ó Continue reading >>, A printable glycemic index list of foods for weight management can guide your food choices and menu planning. The glycemic index (GI) is a measure of the effect carbohydrates have on blood glucose levels. The entire 282-page dissertation plus a dozen appendices is free online. FoodData Central takes the analysis, compilation, and presentation of nutrient and food component data to a new level. The other 6 grams in the 28 grams ounces of butter is made up mostly of water, along with a small amount of milk solids. Jan 19, 2017 - Posts about insulinogenic foods written by Marty Kendall Diabetes Research: Groundbreaking Diabetes News of 2017 | Reader's Digest, Caffeinated and Decaffeinated Coffee Consumption and Risk of Type 2 Diabetes: A Systematic Review and a Dose-Response Meta-analysis, Chelsea warns of ‘horrifying’ report on diabetes & global warming; response is NOT what she’d hoped for, Trumps OMB Director Wasnt Alone in Denigrating Diabetes, Carb counting for diabetes: Meal planning to manage blood sugar, New Theory About the Cause of Type 1 Diabetes, The Diabetes Exchange Diet's List of Free Foods, Diabetes Diet: Eight Foods To Put On Your Shopping List. Everyone knows that vegetables are healthier than cookies. In other words, while the meat and eggs didn’t cause a spike in blood sugar the way most carbohydrates do, they did result in an unexpectedly significant rise in insulin. It has been established that a diet characterized by carbohydrate-containing foods, which induce low glycemic responses after the consumption of a meal, has advantageous effects on the risk factors for type 2 diabetes and cardiovascular disease (1– 4).In 1998, the FAO/WHO recommended that the bulk of carbohydrate-containing foods in the diet be those with a low glycemic index … In reality, we typically eat mix-meals which throws Beets have a moderate index. The index is similar to the Glycemic Index (GI) and Glycemic Load (GL), but rather than relying on blood glucose levels, the Insulin Index is based upon blood insulin levels. When you learn a few principles of low glycemic eating you will find that you can easily follow the low glycemic way of eating. The Insulinogenic Index Is a Valid Marker of Beta Cell Function in Different Metabolic Categories Oral glucose test (OGTT) is la Oral glucose test (OGTT) is largely used as diagnostic test and to evaluate metabolic status. Insulin indexes are scaled relative to white b 3. Protein rich foods are the second most insulinogenic (i.e. However, some nutritionists also divide foods into a dried way: Then the low GI ends at about 30, the middle one at about 70 and everything above it has a high GI. 2. Additional foods: 1. Foods with a high glycemic index (GI) raise blood sugar quickly and may cause health issues if someone eats too many of them. But there’s more to the story here. white potatoes, potato chips, white rice, processed foods in boxes, any foods with added sugar, any foods with high fructose corn syrup, frozen desserts, ice cream, candy, sugary snacks. Foods on the glycemic index diet are scored on a scale of 0 to 100 based on how much they raise your blood sugar level. Skip to main content. the amount of insulin released in response to glucose, fructose, lactose, etc. Video of the Day Olive Oil and Other Plant-Derived Oils Oil is pure plant-source fat, whether it is olive, canola, sunflower, sesame, peanut, coconut, soy or corn. The Insulin Index can be more useful than either the Glycemic Index or the Glycemic Load because certain foods (e.g., lean meats and proteins) cause an insulin response despite there being no carbohydrates present, and some foods cause a disproportionate insulin response relative to their carbohydrate load. That’s where Professor Jennie Brand-Miller was Bell’s supervisor has led much of the world’s research of both the insulin and glycemic indexes for more than two decades. Unfortunately, subsequent research has shown us that are several major problems with basing food choices solely off the glycemic index. The creation of the glycemic index was a quantum leap forward in highlighting how seemingly similar foods can have wildly different biochemical properties in our bodies. Browse the BBC Food recipe archive by ingredients and learn more about the storage, preparation and purchasing of your foods. Why? Wild swings in insulin also tend to provoke increased hunger, which is not good if you are trying to control intake and by extension, body weight. Learn which foods are high in iron. Here, learn which foods to eat and avoid on an anti-inflammatory diet. Living with someone who has Type 1 Diabetes for fifteen years I’ve gained an intimate understanding of how different foods will take your blood glucose levels on a wild ride. The food insulin index is measured as the amount of insulin in the blood of test subjects during the two hours after consuming 1000 kJ (239 kCal) of food. They are not GI values. Low blood glucose levels drive you to eat until you feel good again. French fries and other fried foods. Dieters and people with diabetes use the Glycemic Index because blood sugar levels can impact fat storage and the progression of diabetes. chicken, fish) Fatty foods are the least insulinogenic (i.e. She led a systematic review and meta-analysis of the “Efficacy of carbohydrate counting in type 1 di Protein-rich foods can also stimulate insulin secretion without increasing blood glucose concentrations. As well as identifying nutrient dense diabetic friendly foods, we can use the food insulin index to highlight more insulinogenic nutrient dense higher energy density foods for use by athletes or people wanting gain weight. But there are also best choices within each food group. It promotes the storage of nutrients after all. Continue reading >>, Does anyone have any good lists or references to the different levels of insulin released from various types of food? Dialog. Explanation of Index[edit] The Insulin Index is not the same as a glycemic index (GI), which is based exclusively on the digestible carbohydrate content of a food, and represents a comparison of foods in amounts with equal digestible carbohydrate content (typically 50 g). It makes no difference to this equation whether the fat is saturated or unsaturated. What Are The Effects Of Too Much Metformin? Food Food Type Glycemic index Insulin index Satiety score All-Bran: Breakfast cereal: 40 ± 7: 32 ± 4: 151: Porridge: Breakfast cereal: 60 ± 12: 40 ± 4: 209: Muesli: Breakfast cereal: 43 ± 7: 46 ± 5: 100: Special K: Breakfast cereal: 70 ± 9: 66 ± 5: 116: Honeysmacks: Breakfast cereal: 60 ± 7: 67 ± 6: 132: Sustain: Breakfast cereal: 66 ± 6: 71 ± 6: 112: Cornflakes: Breakfast cereal: 76 ± 11: 75 ± 8: 118: Average: But what about that rise in insulin? It's important to eat low glycemic carbs that are high in fiber and nutrients and avoid the starchy, more processed high glycemic carbohydrate foods. "In fact meat … Some foods have a mixed content of carbohydrate, protein, and fat. Glycemic index (GI) is a measure of how quickly a food can make your blood sugar (glucose) rise. Type 2 diabetes is... Duromine is kind of phentermine is the better option, or zoloft. An appendix lists the glycemic index of about 137 foods. hì@D¾‹ÔÏ(àå�fíùÕyÛŠº�MM¿+õ›è¶"ÌDÙ¹ÿØü¸’¾—Êö&$Úê­‡C׊m×Uƒ(‹VÜ+üql+Øã^o½Èî¦�zŸ7İ£:Ü«^È. insulinogenic index: The ratio of insulin to glucose, a measure of the effect of meals on prediabetics As stated by Dr. John McDougall, "Advocates of high-protein diets explain the reason people are fat is not because of the fat they eat, but because of hyperinsulinism and insulin resistance. How Many Carbs Per Meal Should A Diabetic Have? Continue reading >>, Due to rising obesity and insulin resistance rates, low-carb and Paleo diets have become a popular approach to the growing population of overweight Americans. Serving size Fiber (grams per serving) Pumpkin, canned ½ cup 5.0 Spinach, boiled ½ cup 2.2 Spinach, raw ½ cup 0.8 Squash, winter ½ cup 3.0 Sweet potato, baked 1 medium 3.0 Tomato, raw 1 medium 1.0 Cereal Serving size Fiber (grams per serving) All … In a healthy person that has fasted for more than 10-12 hours overnight, cheese and steak can cause a small rise in blood glucose in the second hour of our 2 hour test periods due to gluconeogenesis. Plan your meals around fresh vegetables and fruits. A simple way is the insulinogenic index (IGI): ratio of insulin concentration at 30 min minus fasting insulin to the difference of glucose at same time. A best choice is a food that is better for you than other foods in the same group. Carb rich foods are the most insulinogenic (i.e. Commission and its priorities; Policies, information and services; Home - European Commission. Only foods that contain carbohydrates have a GI. Zero-glycemic foods—those without carbohydrates—include items like meats, fish, and oils.Pure sugar has a glycemic index of 100. soda and other sugar-sweetened beverages. So, the key is to use GI in the context of balanced eating. FIBER IN FOODS CHART Vegetables (cont.) In other words, while the meat and eggs didn’t cause a spike in blood sugar the way most carbohydrates do, they did result in an unexpectedly significant rise in insulin. These are the foods most recently tested for their food insulin index: It’s no coincidence that Kirstine Bell’s Ph.D. comes from the University of Sydney. Meat raised insulin levels higher than a large apple, a cup of oatmeal, a cup and a half of white flour pasta. 3. On the basis of weekly changes in body weight, the AN participants were divided into good (≥0.5 kg) and poor (<0.5 kg) responders. beets, carrots, corn, parsnips. List: Foods with a low GI. Actual (sugar) has a glycemic index of 100 and other foods measured are ranked as low, moderate and high GI foods. Continue reading. butter, bacon) How is it calculated? Check out our visual guide. "In the insulin index study, we measured glycemic scores and insulin scores for 1000 kJ portions of foods. High protein, virtually no-carb foods like meat and eggs, while low on the glycemic index, measured high on the insulin index. Carbohydrates Food List - 4 - Disclaimer: This document contains information and/or instructional materials developed by Michigan Medicine for the typical patient with your condition. A major disadvantage in this connection is the shortage of low-GI foods, and many common starchy staple foods, such as bread products, breakfast cereals and potato products, have a high GI. Novel food catalogue. For those of us who have diabetes, this index is also a more comprehensive guide to blood sugar control than the glycemic index. The development of heart disease, high blood pressure, and cancer are all thought to have this anabolic or insulinogenic response. butter, about 1 ounce, contain 22 grams of fat and no carbohydrates or protein. Continue reading >>. It is probably more helpful, and certainly more accurate, to think of oil as being fat, rather than containing fat. chicken, fish) Fatty foods are the least insulinogenic (i.e. Insulin encourages fat cells to store fat and prevents the release of fat from these cells. Your body needs iron to make new blood cells, replacing the ones lost through blood donations. Use the guide below to get ideas of additional calcium-rich foods to add to your weekly shopping list. Nutrient dense insulinogenic foods for bodybuilding. Protein also stimulates insulin release. While Holt and her co-authors found a high correlation between glycemic index and insulin index measurements, they stumbled upon an intriguing exception. When we decided we wanted to have kids, we found a great doctor who helped us to understand how to match insulin with carbs, but moderating the input of carbohydrate that necessitates insulin was never mentioned by physicians, endocrinologists or diabetes educators. INTRODUCTION. Since she was ten, my wife Monica’s had to manually manage her blood sugars as they swing up with food and then drop again when she injects insulin. When it comes to buying foods in a box or jar you will have to be good at reading labels By the same logic, low carbohydrate diets are better for weight loss due to the low levels of insulin, which doesnt stop fat burning. all white foods including breads, pastries, muffins, doughnuts, bagels, biscuits, corn bread, croissants, baguettes, hamburger and hot dog buns, pancakes, most commercial breakfast cereals, refined flour crackers, cakes and refined tortillas. Carbohydrates with a low GI value (55 or less) are more slowly digested, absorbed and metabolised and cause a lower and slower rise in blood glucose and, therefore insulin levels. This list of carbohydrate foods will prove that all carbohydrates are not created equal. Continue reading >>, A short while ago, I did a post on insulin and body fat (Insulin, Body Fat and You). soda and other sugar-sweetened beverages. They are foods for diabetic diets as well as to lose fat! 2. [1] have noted that the glucose and insulin scores of most foods are highly correlated,[2] but high-protein foods and bakery products that are rich in fat and refined carbohydrates "elicit insulin responses that were disproportionately higher than their glycemic responses." The Insulin Index represents a comparison of food portions with equal overall caloric content (250 kcal or 1000 kJ), while GI represents a comparison of portions with equal digestible carbohydrate content (typically 50 g) and the GL represents portions of a typical serving size for various foods. Insulin Index (240 calorie portion, relative to white bread) Peanuts ++ 20 Special – K +++++| 66 Eggs +++ 31 Honey Smacks +++++| 67 All-Bran +++ 32 Sustain +++++ 71 Porridge ++++ 40 Doughnuts +++++ 74 High, Medium and Low GI Foods. How to use GI The GI value of a food is tested on the food when eaten on its own, and there are published lists of high, medium and low GI foods. The food insulin index chart from the original paper below shows jelly beans have the largest insulin response, while foods like eggs, butter, bacon and olive oil have a much smaller insulin response over the two hours of the test. Look at what's in season where you live if possible and let those foods dictate your menus for the week. In this article, I will share my insights from the latest food insulin index data and how we can apply it to optimise our insulin and blood glucose response to the food we eat. One ounce of macadamia nuts contains 21grams fat, with only 4 grams carbohydrate and 2 grams protei In ou The foods below all have a glycemic load between 11 and 19, which is considered a medium rating, so are foods that cause some increase of blood sugar but not to an extreme extent: Pearled barley: 1 … Interestingly, Holt, her supervisory co-authors, or other researchers haven’t chosen to conduct further research to update the “preliminary” results of their insulin index study since its creation eleven years ago now. The study, titled “Clinical Application of the Food Insulin Index to Diabetes Mellitus,” is Kirstine Bell’s Ph.D. dissertation from Australia’s University of Sydney. The insulin index compares foods in amounts with equal overall caloric content (250 kcal or 1000 kJ). Obviously, the index has some eyebrow-raising potential, especially in those of us who choose a high protein diet. What sweeteners are good on a low-carb diet? It's the carbohydrate foods that affect blood sugar. Note that this categorization does not apply to type I diabetics, who are not able to produce insulin at all. Insulin, in and of itself, is a good and necessary thing. High protein, virtually no-carb foods like meat and eggs, while low on the glycemic index, measured high on the insulin index. Lentil Soup (ready-made) Split Pea Soup (ready-made) Additional foods: 1. Try to avoid or limit these foods as much as possible: refined carbohydrates, such as white bread and pastries. Making sense of the Food Insulin Index (with recipes and food lists to stabilise insulin and blood sugars and help you to lose weight) A detailed look at the strengths and weaknesses of the food insulin index data to optimise your blood sugars, insulin and weight loss. The dietary advice she received over the past three decades living with Type 1 has been sketchy at best. Although carbs do make our insulin levels go up, Dr. Micheal Greger points out in the video above that scientists have known for over a half century that protein makes it go up as well. I think it goes without saying that teaching people how to avoid crazy swings in insulin is a good thing. Aim was to compare IGI with an index of BF (both in (pmol/l)/(mmol/l))obtained in the same subjects after an intravenous glucose bolus. This study and subsequent studies showed that any type of meat (beef, chicken, and pork) produced substantial insulin secretion. 3. However, scientists know that many factors influence the glycemic index. Consequently, the majority of calories from a low-carb diet come from meat, which contains protein and fat, but no carbs. Below we've highlighted a few points from the Insulin Index: "Some of the protein-rich foods (beef, cheese, eggs) had larger insulin responses per gram than did many of the foods consisting predominately of carbohydrate." FoodData Central: Can be used by, and has benefits for, a variety of users, including researchers, policy makers, academicians and educators, nutrition and health professionals, product developers, and others. I know that sugar and dairy have higher responses than say protein, but I am under the impression that different types of protein trigger different levels of insulin. That would mean that it stimulates little insulin release. When she was first diagnosed, Monica tells the story of being made to eat so much high carb food that she hid it in the pot plants in her hospital room. These foods stimulate fat-storage and cause food cravings. which are higher in fat and salt. Food in Every Country: Algeria to France, Germany to Japan, Kazakhstan to South Africa, and Spain to Zimbabwe, Cumulative Index List of Low Insulin Index Vegetables Bell Peppers. ; or butter, cream, CO, etc. For years the limitation of the food insulin index (also known as just the insulin index) was the few foods tested. Fats and protein do not. A low glycemic index is referred to when the value is below 50. Packed... Cabbage. Mark; Abstract The metabolic syndrome (type 2 diabetes, obesity, hypertension, atherosclerotic cardiovascular disease, dyslipidaemia, and hyperinsulinaemia), is … And all lower GI foods are not necessarily healthy – chocolate and ice cream have a low to medium GI rating. Fruit in its natural state provides fibre, nutrients with a lower energy density. Foods with a … The Glycemic Index (GI) is a relative ranking of carbohydrate in foods according to how they affect blood glucose levels. Obviously, the more structured resistance training you follow and the better you time your insulin spikes, the better able you are to use insulin’s mass building effects for muscle growth and not fat. Dietary fat by itself, including these foods, does not cause insulin release. sweetened almond, soy and coconut milks. $19.95. If you have diabetes, you are likely familiar with this feeling. You need to constantly monitor your diet and ensure that your blood sugar level i... A printable, colorful PDF version of this article can be found here.