Science Essays
Dvd vs
Dvd vs. vcr INTRODUCTIONThis report will strive to clearly discern the differences between the average home Video Cassette Recorder (VCR) and the recently developed Digital Video Disc (DVD) system. These two home entertainment components have very clear differences. It is important for consumers to carefully consider each of these concerns before deciding on the home entertainment component that is right for them.When considering the purchase of a home VCR or DVD system, consumers should car...
Dvd
Dvd Research on DVD A Brief Summary DVD is a new technology very similar to compact discs. A DVD looks just like an ordinary compact disc, however a DVD can hold up too 6 times as much as a CD! That's 4.7 gigabytes! This gives enough room to hold an entire movie at twice the quality of VHS with theatre quality sound (better than CD-quality). Since it is on a disc, you can jump to any scene instantly, and you never need to rewind. The Different types of DVD include: DVD-R...
Dyslexia
Dyslexia Growing, developing and learning are the facts of life for all children. Each day children are faced with many new concepts and various challenges. Can you imagine how it feels for a child to face not only new challenges life has, but to face these challenges while living with a learning disability? These challenges are met not just when they begin school either. Students suffer from learning disabilities from the moment they begin learning, not when they start school. Learning disa...
Dreams
Dreams Dreams: Could They Be All They Are Made Out To Be? �Over a seventy-year life span, you�ll devote at least fifty thousand hours to dreaming� (Segell 42). These dreams can be made up of many things. They can be a window into another world or �like a urgent fax from your subconscious� (Graves 97). Many things can affect what we dream about and they are not always our previous thoughts. Things such as gender, information gained during the course of time, or even sensa...
Drinking water contamination
Drinking water contamination Due to the Safe Drinking Water Act (SDWA), America's drinking water is safer than it has been in decades, and of better quality than that of many other countries. Accordingly, many Americans believe that while people elsewhere may have reason to be concerned about getting sick from contaminated tap water, we are safe. Yet, incidents in the United States � such as the outbreak of the microorganism cryptosporidium in Milwaukee's water supply in 1993 that killed m...
Droughts
Droughts Drought, condition of abnormally dry weather within a geographic region where some rain might usually be expected. A drought is thus quite different from a dry climate which designates a region that is normally, or at least seasonally, dry. Athough the quantity of the worlds freshwater resourses is more than adeguate to meet human needs, but uneven distribution from place to place can result in serious droughts. The word drought is applied to a time where an unusual shortage of ...
Drug identification with gas chromatography mass spectrometr
Drug identification with gas chromatography mass spectrometr Drugs are used everyday by people in many different ways for many different reasons. Drug testing has become a standard in pre-employment testing, because of the wide variety of drug use in today's society. Drugs tested for by a possible employer include Cocaine (crack), Amphetamines (crystal), Opiates (codeine, morphine, heroin), PCP (phencyclidine), and Marijuana. Gas chromatography/mass spectrometry is used to test hair and urin...
Down syndrome 3
Down syndrome 3 Down Syndrome Down Syndrome is a chromosomal disorder. It occurs in about 1 of every 800 births. People with Down syndrome may have mild to severe learning disabilities. Physical symptoms include a small skull, extra folds of skin under the eyes, and a protruding tongue. People with Down syndrome are subject to a variety of medical problems including heart abnormalities and thyroid gland dysfunction. Survival rates have been increased dramatically in recent years as proble...
Down syndrome 4
Down syndrome 4 Introduction Down syndrome is a chromosomal abnormality. It is the most frequent form of mental retardation and is characterised by well-defined, distinctive phenotypic features and natural history. An error in cell development results in forty-seven chromosomes rather than the usual forty-six. There are three major types of Down syndrome. About ninety-five percent of individuals with Down syndrome have Trisomy 21. There is also Translocation and Mosaicism. D...
Down syndrome
Down syndrome Down Syndrome Down syndrome is a combination of birth defects including some degree of mental retardation and characteristic facial features. It is also called trisomy 21. Down syndrome occurs when there is an abnormality in chromosome 21. It is found in approximately 1 out of 1000 all live births. Each year, 3,000 to 5,000 people are diagnosed with Down syndrome in the United States. The formal story began in 1866, when a physician named John Langdon Down ...
Dreams rem
Dreams rem Dreams are a form of cognitive activity that occur during sleep. Like vivid memories and daytime fantasies, dreams involve visual images in the absence of external visual stimulation. Some dreams are so realistic and well organized that we feel as though they must be real-- that we simply cannot be dreaming this time. Dreaming has always been the subject of controversy. Egyptian papyrus documents dating back to 2000 BC discuss dreams and their interpretations. In ancient Greec...
Dna
Dna DNA DNA, or Deoxyribonucleic Acid, is described, in Encarta Encyclopedia as a genetic material of all cellular organisms and most viruses. DNA carries the information needed to direct protein synthesis and replication. Protein synthesis is the production of the proteins needed by the cell or virus for its activities and development. Replication is the process by which DNA copies itself for each descendant cell or virus, passing on the information needed for protein synthesis. In mos...
Do science and technology provide a solid base for technocra
Do science and technology provide a solid base for technocra To answer this question one must first understand that every politico-economic ideology, like every religious belief, proclaims that it has the one true doctrine and that all others are entirely different or at opposite ends. In most instances individuals join in voluntary association to act upon those opinions, ideas or beliefs which they hold in common. These opinions, ideas or beliefs may or may not be based on facts and hence...
Dolphins 2
Dolphins 2 Contact A great philosopher by the name of Plutarch once wrote that the dolphin �is the only creature who loves man for his own sake. To the dolphin alone, nature has given what the best philosophers seek: friendship for no advantage.� The foundation to a relationship like this is based on communication. In this paper, evidence will be presented to show that it is possible for dolphins and humans to communicate in a significant and meaningful way. Throughout recorded ti...
Down syndrome 2
Down syndrome 2 Down syndrome is one of the most frequently occurring birth defects in the world. It is a chromosomal abnormality which results in 47 chromosomes, instead of 46, with an extra chromosome being 21. Because the majority of Down syndrome cases affect the twenty-first chromosome, it is commonly called "trisomy 21." Down syndrome is usually caused by a cell division error, which is known as non-disjunction. This occurs when an embryo develops with three number ...
Dna 4
Dna 4 The molecule responsible for the transformation of characteristics form one generation to the next is called DNA. The genetic material, located in the chromosomes is a combination of acid and histones. DNA is made up of units called nucleotides. Nucleotides are made up of 3 components, a five carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base. This base can be either adenine, guanine, thymine or cytosine. There are 2 strands of nucleotides in a double-helix - the...
Dna and forensics
Dna and forensics DNA and Forensics In my essay I will discuss the topic DNA and Forensics. This is an interesting topic because there have been great advances in the field of forensic science that have affected it's credibility and usage in solving crimes that would otherwise go unsolved. DNA can be found in almost any bodily fluid (semen, saliva, blood, etc.) and in less obvious places such as a strand of hair. It has become a crucial part of investigating crimes, and will continue t...
Dna chips and the pharmaceutical industry
Dna chips and the pharmaceutical industry DNA CHIPS AND THE PHARMACEUTICAL INDUSTRY INTRODUCTION When future historians look back on the greatest scientific advancements of the 20th century, they will without a doubt focus on only three events: the Apollo Moon landing, the invention of the microprocessor, and possibly the greatest scientific endeavor yet, genomics, the science of identifying genes and how they work in humans. It is possibly not a total coincidence then that two of ...
Dna replication
Dna replication DNA REPLICATION WHAT IS DNA? DNA is a molecule that has a repeating chain of identical five-carbon sugars (polymers) linked together from head to tail. It is composed of four ring shaped organic bases (nucleotides) which are Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). It has a double helix shape and contains the sugar component deoxyribose. THE PROCESS OF DNA REPLICATION How DNA replicates is quite a simple process. First, a DNA molecule is ...
Discussions on darwin
Discussions on darwin Man, due to a force unknown to him for millions of years, rose to the very top of the organic scale. Only in the past one hundred years have men finally put aside their Biblical and mythical tales about creation, and looked to the facts in order to piece together a logical explanation for the origin of mankind. In turn, men were now able to explain the enigma of their origin without the presence of a supernatural being responsible for their creation. At the head of a...
Disease in africa
Disease in africa Disease in Africa "The fact remains that lowland, tropical Africa may well have the most intractable disease environment in the world."(Bohannan & Curtin,35) In order to understand diseases in Africa, one must first be acquainted with its geology. Africa is a gigantic landmass that is over 5200 miles long and 4600 miles wide. The continent is a vast plateau with five different types of physical regions. The first type of physical region is called the Mediterranean -t...
Dna 2
Dna 2 In the last 10 years, there has been some scientific leaps concerning diabetes, and genetic engineering. The increasing incidence and diagnostic detection of diabetes worldwide coupled with changing trends in the food animal market stimulated people to seek alternative sources of insulin completely independent of an animal-gland source. (Ryan, 1986). The basic recombinant DNA process of formulating insulin was developed. DNA carries the genetic information that determines the fate of ...
Dna 3
Dna 3 DNA - Deoxyribonucleic Acid - the material that codes for amino acids which form proteins, which in turn carry out functions of the cell. DNA is responsible for building life. Our physical characteristics, susceptibility to some diseases and disorders (e.g. breast cancer, sickle cell anemia), and a few behavior characteristics are passed from generation to generation through DNA. DNA controls everything about the way we look, from the color of the eyes to how tall you are to the width ...
Dingo
Dingo Nobody is exactly sure where the dingo �Canis familiaris dingo� came from, it isn�t originally from Austrailia but arrived between 3,500 to 4,000 years ago. The oldest dingo fossil is dated at about 3,400 years old. It is thought that the dingo is from the same family as the Indian Wolf, like many domestic dogs (Canis familiaris), but it has enough of its ancestors charachteristics that it has its own variety. There are two theories about where the dingo came from. One ...
Dinosaur history
Dinosaur history When dinosaur bones were first found they thought that they belonged to giant lizards. The word "dinosaur" came from the Greek words deinos, meaning �marvelous� or �terrible,� and sauros, meaning �lizard.� The larger dinosaurs must have seemed to be terrible to the smaller animals. Some of the first dinosaurs were only about as big as a small dog. That is how big the horses of that time were. Over the years, as the dinosaurs aged, they grew to be much more lar...