Critical Period in Human Growth and Their Relationship Essay Example

Critical Period in Human Growth and Their Relationship Paper Critical Period in Human Growth and Their Relationship to Diseases of Aging Pr ©CICS Growing, developing and aging (GA) are characteristic of all living organisms and have a multifarious etiology. Three major intrinsic categories influence growth, development and aging in humans. These include genetics, hormones (endocrine system) and appearance. An extrinsic Influence Is the environment. These categories all Interact with each other to determine roles of Individual factors. Growth and development patterns are flexible (plastic) to a point depending on when and how significant the environmental perturbation. During growth, when certain environmental factors are compromised, the body slows its growth and can catch up to its genetic programming providing the perturbations are not too Intensive or prolonged. Diseases that involve high temperatures are the most stressful for causing growth disruption. Some tissues and systems are more readily thrown off their developmental pathway. The hypothesis that the body can get thrown off its programmed genetic growth by numerous Interacting factors Is called the concept of heritability. Knowledge of tissue growth is important primary information to understand what happens to us when we age. If we come to an understanding of growth, development and aging, including the processes involved, we will be able to identify early deviations that may precede disease in later life. There Is an association between a low weight at birth, rapid postnatal growth and childhood and adult obesity and glucose tolerance. We will write a custom essay sample on Critical Period in Human Growth and Their Relationship specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Critical Period in Human Growth and Their Relationship specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Critical Period in Human Growth and Their Relationship specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The rebound adversity timing during adolescence can also be a precursor to the development of obesity at a later life stage. Cameron and Democrat identify fetal life, infancy, childhood, and adolescence as the critical growth periods. Each of these stages involves different aspects of human growth and development. Environmental affects during these stages are necessary In order to allow for proper growth but can also have a deleterious effect on growth and development which can influence Complex Chronic Diseases (CDC). These key phases have been examined in many publications. According to Noel Cameron and Ellen W. Demarcate, a developing fetus uses a process called programming In order to counter Insults during the pre-natal period that may effectively deal with the immediate issue but that may result in long term disadvantages such as articulators disease, (hereafter referred to as C.V.), hypertension, Type II diabetes and the development of obesity later in life. One way in order to test for a pre-natal Insult Is through enamel hyperplasia. During enamel development, If there Is a major insult, the calcification of the enamel is affected leaving a permanent line on the 1 OFF genetic control, the timing of the insult can be determined by noting the position of the line(s) on the crown. There is much debate on whether after early childhood if adipose is post-mitotic; weight increase after childhood is a function of hypertrophied semantics. During the fetal stage of development, the brain grows multiplicatively up to the 6th prenatal month then has exponential ascetic growth in infancy. The skeleton has exponential growth in prenatal and into childhood at which point it follows a general growth curve until adolescence. Muscle, like the brain, is post- mitotic but multiplicative growth last to birth then it is ascetic. Adipose tissue is abundant at birth and constitutes 25% of babies weight. Babies lose the adipose tissue during childhood but it increases at adolescence, particularly in females where he menses will be delayed if there is not a threshold amount of adipose tissue. There is controversy over whether fetal environmental stresses are independent from genetic factors. Certain populations are more prone to obesity than others such as Meridians which has led to the Thrifty Gene Hypothesis. The concept is that there are plutocratic effects of specific genetic variants that take place in fetal development and in cardiovascular, metabolic and hormonal regulation later in life (2002:178). Certain groups of North American aboriginals have a high predilection to developing Type II diabetes. Infectious diseases are known to inhibit growth. The exact mechanisms are not known but definitely, those diseases that have fevers (febrile) disrupt growth. The fever disrupts normal cell division (reduced mitotic index). This slows psychogenesis but does not seem to influence stoninesss resulting in growth arrest lines on long bones. Infectious disease may reduce growth hormone because of an increase in corticosteroids from the adrenal cortex. During illness, malnutrition acts syntactically with disease to disrupt growth. Studies have shown an association between birth weight and the risk of diabetes ND glucose intolerance. The proximate mechanism behind the relationship between birth size and disease risk is that the fetus adapts to maternal under-nutrition by growth retardation which leaves the adult better equipped to cope in a deprived rather than an enriched postnatal environment. The key is the plasticity during the course of post-natal development. This is not necessarily low birth weight alone which may have resulted from energies being routed to the growth and development of the brain to the detriment of the development of other tissues. This environmental impoverishment is believed to result in permanently modified teal physiology and programming. The proposition is that once there is a modification in fetal programming, organ systems are then unable to act in response to a high-calorie, high-fat, and high-sodium diets leading to a higher incidence of adult disease (2002:163). Catch-up growth after an insult can result in changes to the timing of peak growth in certain organs. The hypothesis is that such things as the number of kidney cells at birth, (neoprene), is due to nutritional deficiencies during pre-natal life that will affect risk of hypertension in later life. Results from some tidies have proposed that malnutrition may retard the growth and development of the hypothalamus in such a way that appetite control and energy maintenance are increased risk of obesity in childhood. New associations have shown that small-for- gestational-age individuals are born with enhanced insulin sensitivity and the insulin resistance appears in later life which translates into a predisposition for diabetes. Childhood obesity tends to lead to a higher incidence of obesity during puberty. If the adversity rebound has taken place before the age of 6, obesity may be entrained during development (2002:169). Children with this early adversity rebound tend to have an advanced maturation of the skeleton that can also influence an earlier maturation of puberty which brings an increased risk of adult obesity. There is a lack of a clear correlation however as other factors such as parental and earlier obesity cannot be excluded from the analysis and are themselves risk factors for obesity. An increased rate of growth in childhood also means that there is an increased rate of cell turnover which can in turn lead to the risk of the duplication of malignant cells. Rapid growth is enabled by the protein GIF-I which encourages cell division and impedes apotheosis. Rapid growth also hastens reproductive development. The antecedents of this early onset of puberty, which include rapid growth and obesity, increase the risk of C.V. and diabetes. Obese children and those with high weight/ height ratios reach pubescent maturity much earlier according to Cameron and Demerits studies. Puberty results in many changes within the body. These can include such things as an increase in fat in female bodies (with a corresponding increase in lepton concentrations), and a decrease in fat in male bodies (with a corresponding decrease in lepton concentrations). In epidemiology, it is imperative that there is an understanding of the difference between association and cause. It is difficult to isolate lepton as a master regulatory hormone, orchestrating both the hormones of growth and maturation and weight-regulating mechanisms (2002:173) and more research is needed in this area according to Cameron and Demarcate. Older adults in western societies have numerous complex chronic diseases that include obesity, cardiovascular disease and diabetes that are concomitant of risks of lifestyle as well as their fetal and perennial environments known as the (Doodad) radium shift. The developmental origins of health and disease paradigm (Doodad) is a multi-disciplinary field that studies the way in which environmental factors acting during the phase of developmental plasticity interact with genotypes variation to change the capacity of the organism to cope with is environment in later life (2006:1). Life History Theory (LET) is a branch of evolutionary theory that attempts to account for ways in which the stages of the life cycle and the behaviors associated with them are organized and is the cornerstone of evolutionary medicine. The main concern today is the increasing potential for development of Complex Chronic Diseases such as cardiovascular disease and diabetes. CDC usually has multifarious causes that broadly involve genetics, infectious and non-infectious environmental agents and to look for a single cause is illogical. The molecular clock of aging are made up of a repeating series of six nucleotides (bases). A typical human telemeter may have more than 1500 repeats. As progressive cell divisions occur, the overall chromosomal length gets shorter. A cells age can be determined by examining telemeter length. This reduction of telemeter length impacts degenerative processes of aging through its impact on cellular destructs. Early growth deviation is generally reputed to have a causal link to Complex Chronic Diseases, (CDC). Key environmental factors are the synergistic actions of nutrition and disease. Some nutritional conditions can result in changes in the hormonal environment. Cameron and Demarcate conclude that additional research is required in this area in order to illuminate the evolution of senescence in the human species (2002:178). Cameron and Demarcate recognize that whether he deviation of growth specifically programs health in later years or whether it is only an indicator for the deviations is not known and also would benefit from future studies. References Cameron, Noel, and Ellen W. Demarcate. 2002. Critical periods in human growth and their relationship to diseases of aging. American Journal of Physical Anthropology 119 (ASS): 159-84. Glaucoma, Peter and Mark Hanson, des. 2006 The developmental origins of health and disease: and Overview, in Developmental Origins of Health and Disease. Peter Glaucoma and Mark Hanson, des. Up. 1-5. Cambridge: Cambridge University Press.

Combining Sentences

Combining Sentences Combining Sentences Combining Sentences By Mark Nichol One cure for flabby prose is greater attention to more lean, muscular writing by, whenever possible, creating a subordinate clause for one sentence by combining another sentence with it. Here are five examples of this approach. 1. Robert Gordon Sproul was a member of the University of California’s class of 1912. He was appointed to serve as comptroller of the university in 1914 and then served as president from 1930 to 1958. The two pieces of biographical information can be unified into one sentence by deleting was in the first sentence and making the rest of the statement a parenthetical, then deleting the subject of the second sentence and combining the subject and parenthesis of the first with the rest of the second: â€Å"Robert Gordon Sproul, a member of the University of California’s class of 1912, was appointed to serve as comptroller of the university in 1914 and then served as president from 1930 to 1958.† 2. â€Å"Senate Bill 7 had been written by the Water and Forest Association. It called for the creation of an unpaid three-member commission.† These sentences can be combined with the same procedure as used in the previous example, but the context may require the addition of which and the retention of â€Å"had been†: â€Å"Senate Bill 7, which had been written by the Water and Forest Association, called for the creation of an unpaid three-member commission.† 3. â€Å"The group meets once a week. During each meeting, students participate in a mini-lesson that explains specific conventions or spelling patterns.† Here, cannibalize the first sentence to insert modifying words or phrases based on the two nouns into the second one: â€Å"During each weekly meeting, students in the group participate in a mini-lesson that explains specific conventions or spelling patterns.† 4. He started work on a project he called Real Life/Reel Life. It was based on a book called Screen Test: How Movie Stars Separate Real Life and Reel Life. Alter the first few words of the second sentence to change it to an introductory subordinate clause, then attach the first sentence to it as the main clause: â€Å"Inspired by a book called Screen Test: How Movie Stars Separate Real Life and Reel Life, he started work on a project he called Real Life/Reel Life.† 5. â€Å"The documentary was based on Major Alexander De Severksy’s book Victory through Air Power, which was published in 1942. The book made the case that the nature of war was changing dramatically.† The easiest revision, â€Å"The documentary, based on Major Alexander De Severksy’s book Victory through Air Power (published in 1942), made the case that the nature of war was changing dramatically,† changes the meaning somewhat, attaching the thesis to the documentary rather than the book (which may be valid, as both the book and film may make the case). Here’s an alternative that preserves the intent of the original sentences: â€Å"The documentary was based on Major Alexander De Severksy’s book, Victory through Air Power, published in 1942, which made the case that the nature of war was changing dramatically.† Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Style category, check our popular posts, or choose a related post below:Avoid Beginning a Sentence with â€Å"With†Among vs. Amongst10 Types of Hyphenation Errors

Journalism - Communication Skills Essay Example | Topics and Well Written Essays - 1500 words

Journalism - Communication Skills - Essay Example To enable this relationship to flourish, a person has to communicate well with the partner and be able to understand each other properly, this will make the two partners to always know when there is an issue in the relationship between them and be able to solve the problem. The process of communication is a continuous process that never ends (Ferguson 56). There are three main components of communication that people use in their daily activities. People who work together usually have gotten remarkably different ideas and opinions about the work that they are doing, the values of the work that they do, the beliefs of the different cultures in the world differ from person to person, and the needs of the people change and vary with individuals. People have the ability to relate with each other and be able to exchange different ideas, they are able to understand each other despite the fact that we have different opinions about each other in life, people are able to understand the perspec tives of other people, they are able to sit down and solve issues among them successfully. They are able to use the processes that are outlined with the communication skills to be able do these things successfully without having hiccups. Getting to learn about the communication processes helps us to be able to have effective and efficient communications with other people. For example, in work places let us say a hospital, the doctors have to learn on how to use effective communication skills for them to communicate well and effectively with their patients. For students studying medicine, they have to learn a unit on communication skills that will enable them to be able to sharpen their communication skills and ensure that by the time they will be out to practice they will have grasped on the importance to communicate well with their patients. At the moment, students should learn on how to communicate among themselves as doctors to be. This is because when they will be practising, th ey will be required to communicate effectively and consult each other regarding a problem that a patient is facing. For them to be able to consult each other well without letting the patient know the problem the doctors have to learn how to communicate using the scientific terms that will help them to communicate better. For example, when discussing medication they will use terms like Etymology, and antispasmodics. They should be able to have mastery on the use of these scientific terms so that they are able to communicate amongst themselves without letting the patients know the truth on what they are talking about. The patients will be told the decisions of the doctors in a much simpler language (Ellis 45). The process of communication involves the Para verbal components, the nonverbal components, and the verbal components for a person to be able to pass messages better with other people. The Para verbal component of communication is the channel of communication that concentrates o n the use of the intonation, the volume that is used in communication, the cadence of the language that used in communication, and also the pace that a person is saying words. Non verbal communication is the use of body language, and the necessary paralinguistics to be able to communicate properly and effectively (Condrill, Bough 56). This type of communication has been a significant centre of interest for quite a lot of time in sectors such as doing

Issues in the natural environment created by business Essay

Issues in the natural environment created by business - Essay Example Unfortunately, as Mahatma Gandhi said, â€Å"This world has enough for everyone’s needs but not for everyone’ s greed.’ Fortunately now, the relation between economic growth and its adverse impact on natural environment has been widely recognized, and corrective steps are being taken. Our environment is a complete natural system evolved over the ages and held in fine balance that promoted life on this planet. Human beings are but one part of this intricate ecosystem. All species of life, with the marked exception of human beings, follow the natural process of evolution to the extent the environment permits. On the other hand, the same environment that promoted the human race, has also given it the genius to explore and exploit it for a variety of reasons. People have basic needs in food, shelter and clothing and once these basic needs are satisfied, they aspire for higher needs viz., a better standard of living, leisure and recreation. Businesses meet these demands by exploiting resources found in nature. With the world population rising continuously, the demand for goods and services is increasing faster than the can be sustained by the fragile ecosystem. While there is a limit to the exploitation of the natural resources, there appears to be no limit for the avarice. What started as a welcome industrial revolution in the 20th century, soon gave rise to the much-discussed environmental issues like pollution of air and water, ozone layer depletion, greenhouse gases, global warming, climate change etc. Every business impacts the environment in some way or the other; yet there is also no escaping from business growth. Here lies the dilemma of demand for goods and services from growing economies coupled with their lesser concern for environmental issues on the one hand, and, serious environmental concern from the developed countries, which is impacting their businesses! The all-encompassing word for environmental issues is ‘sustainability’, which is

Achilles' Rejection of Agamemnon's Offer Essay Example | Topics and Well Written Essays - 250 words

Achilles' Rejection of Agamemnon's Offer - Essay Example Greeks heroes were known to perform heroic deeds, and Achilles is an opposite of this. He could have used the opportunity to accept the offer and show his heroism. His action of refusing to participate in the battle stained his heroic code of honor as both his friends, and the Greeks questioned whether he was a patriot to his country (Homer & John, 345). Known by the public as a great fighter, Achilles act of refusing to participate in the battle is an irony. Therefore, all the happenings that took place in the war were blamed on him because, as a warrior, he had refused an honorable settlement and allowed his pride to destroy his nation (Homer & John, 350). In conclusion, the act of Achilles in refusing reconciliation was a wrong act since the result was the fall of Greek and death of other talented fighters. Pride is a healthy aspect for self-image, but when in-excess, it becomes a tool of

The Amelogenesis Imperfecta Health And Social Care Essay

The Amelogenesis Imperfecta Health And Social Care Essay Your sister has noticed that the teeth of her young son are discoloured and has taken him to the dentist. After a series of tests, the condition of X-linked amelogenesis imperfecta is diagnosed. She asks you, a dental student, to explain the reason for this condition. Particularly, she would like to understand why, in this condition, the enamel is malformed, how the enamel differs from normal and the reason her son, but not her, or her husband is affected. Learning outcomes 1. To explain and understand normal enamel formation. 2. To identify the different types of AI and their presentation. 3. To describe the genetic code and various types of genetic mutations that can be found. 4. To understand and describe the phrases; autosomal dominant inheritance, autosomal recessive inheritance and X-linked recessive inheritance. 5. To identify the genes associated with AI. Introduction Amelogenesis imperfecta is a hereditary disorder that affects tooth development and results in the abnormal formation of tooth enamel. In the above scenario our nephew has been diagnosed with X-linked amelogenesis imperfecta. Below I will explore the proposed learning outcomes and take a closer look at the inherited disease. Explain and understand normal enamel formation. The teeth are composed of three mineralised tissues; enamel, dentine and cementum, which surround the inner unmineralised dental pulp. [1] The dental pulp is the only living part of the tooth and is made up of connective tissue, odontoblasts and nerves. It supplies the outer mineralised layers with a supply of organic compounds and the odontoblasts help with the creation and repair old dentin. The nerves inside the pulp are also very sensitive and alert an individual of any injury or trauma that may occur. If the pulp is exposed to bacteria, infections are likely. [2] [3]http://www.dentalhealth.ie/common/images/legacy/dhp/pic_stuctureoftooth.gif Cementum can be found below the gum line covering the dentin and root of the tooth. It helps to anchor the tooth and protect the root. It is continuously formed through life by cementoblasts in the dental pulp as it prone to destruction. [4] [6] FIG.1 Basic tooth structureDentine is made up of tiny tubules and is the most abundant of the three mineralised tissues. It acts as support beneath the enamel covering and has a protective function to the dental pulp. Dental pulp, cementum and dentine are all derived from the mesencymal origin. [5] [7] FIG.2 Enamel structure The head is orientated superficially and the tail towards the tooth root http://www.kck.usm.my/ppsg/histology/e_2_0.jpg Lastly enamel which is derived from the ectoderm is made up of primarily crystalline calcium phosphate and is the outermost component of the tooth and covers the dental crown. The calcium hydroxyapatite enamel crystals are arranged as keyhole shaped rods that span the full thickness of the enamel layer (see fig.2). The enamel crystals have a parallel orientation and any gaps between the rods are filled with further crystals. Enamel is the hardest most mineralised structure found in the human body. [4] [8] Enamel is formed by the process of amelogenesis after dentine is formed in the process of dentinogenesis. There are four main stages to amelogenesis; Presecretory, secretory, maturation and post maturation. [1] [9] FIG.3 Basic tooth structureThe presecretory stage starts with proliferation of the oral epithelium to form the dental lamina, further proliferation with occur at the site of each future tooth and there will be an outgrowth of cells; this is called the bud stage. This bud of cells then enlarges and develops a cavity in the cap stage and further growth and development will lead to the development of four recognisable layers in the bell stage. Finally the internal enamel epithelium will cease to divide and the dental lamina will degenerate leaving being the early developing tooth. [1] In the secretory stage a partially mineralised enamel matrix is deposited directly on the surface of the previously formed dentin by adjacent secretory stage ameloblasts. [1] The organic partially mineralised matrix is produced as a result of the combined actions of the rough endoplasmic reticulum, Golgi apparatus and secretory granules. The ameloblasts will move away when the first layer of enamel is deposited on the dentine allowing the Tomess process to develop at the secretory pole of each ameloblasts. The Tomess process is responsible for the formation of enamel rods as it lays down the crystals of the enamel matrix. The ameloblasts lie adjacent to the stratum intermedium which contains alkaline phosphotase which is responsible for calcification of the tooth enamel. These ameloblasts continue to produce the enamel matrix until full thickness is reached. [4] Maturation of the partially mineralised enamel matrix involves the removal of organic material and the continuous influx of calcium and phosphate. [4] Maturation stage ameloblasts differentiate from secretory stage ameloblasts and they now contain high numbers of mitochondria to carry out their function as a transport epithelium moving substances into and out of the maturing enamel. The maturing enamel matrix contains four main types of protein; amelogenins, ameloblastins, enamelins and tuftelins. The amelogenins are important in maintaining the spaces between the enamel rods and the ameloblasts control the elongation of the enamel crystals, both of these proteins are removed from the mature enamel. Enamelins undergo cleavage as the enamel matures and will only be found on the surface of the crystals.Tuftelins are present in mature enamel and responsible for hypomineralisation. [1] [4] In the final stage of post maturation the enamel organ will degenerate and the tooth will erupt and become exposed to the oral environment. [1][4] Identify the different types of AI and their presentation. Amelogenesis imperfecta is a group of hereditary disease that affects both the primary and secondary dentition. It results in the enamel becoming hypoplastic, hypomineralised, discoloured and sensitive. [10] There are four main types of amelogenesis imperfecta (AI) that have been identified because of their differences in enamel defects that present in patients. In Hypoplastic AI (type1) the enamel is of normal colour but much thinner as the enamel has not formed to normal thickness, the enamel can also have pits and grooves due to the disturbance in differentiation of ameloblastins. In hypomaturation(type 2) AI the teeth are of normal shape but have a mottled, dark, opaque appearance and chip away easily from the underlying dentine because of a change to the rod structure. Hypocalcified AI (type 3) has poor enamel mineralisation and a defect in its matrix structure making it very soft and susceptible to abrasion; its appearance is dark and chips easily. [1] [11] (see fig.4).http://www.ojrd.com/content/figures/1750-1172-2-17-1-l.jpg Finally hypoplasia (type 4) AI is a combination of hypoplastic and hypomaturation AI. It is characterised by a reduction in enamel thickness and the enamel has a yellow brown mottled appearance. [13] [12] FIG.4 Phenotypic descriptions of amelogenesis imperfecta. hypoplastic (a, b, c, d), dysmineralised (e, f), hypocalcified (g, h) hypomineralised form (e and f) The hypomaturation forms (g, h) Describe the genetic code and various types of genetic mutations that can be found. [15] FIG.5 Genetic information is encoded in the base sequence of DNA molecules as a series of genes. The genetic code describes how base sequences are interpreted into amino acid sequences during protein synthesis via transcription and translation. [14] http://sjesci.wikispaces.com/file/view/DNA-to-codon.gif/155543209/DNA-to-codon.gif The DNA sequence of a gene is divided into a set of three bases called a codon (see fig.5). Each codon gives rise to a particular amino acid or a stop signal. The genetic code is referred to as degenerate because each amino acid is encoded by more than one codon; there are 64 possible combinations of codons from the 4 nucleotide bases (Adenine, guanine, cytosine and uracil or thymine) but only 20 different amino acids. (See fig.6)http://2.bp.blogspot.com/-i-CYqAFf61o/TZXYoBQmXrI/AAAAAAAAB5g/5PmMdfOP1PQ/s1600/genetic-code-1.jpg This degeneracy minimises the possible effects of mutations as alterations to the base sequence are less likely to change the amino acid so changes to the protein structure and function are avoided, this is known as a silent mutation. Protein synthesis always starts with the initiation codon AUG which encodes the amino acid methionine but this is later removed. Protein synthesis is terminated by the any of the three stop codons; UAG, UGA and UAA. [14][16] [17] FIG.6 DNA mutations can however cause genetic disorders and cancers. A gene mutation occurs when there is a change in the DNA sequence that makes up a gene; these can be classified as either point mutation which involves the alteration of a single base or gross mutations which often involve the alteration of longer DNA sequences. There are several types of point mutations. Missense mutations occur when a single base is altered or substituted and a different amino acid is produced. Nonsense mutations result in translation ending prematurely because a nucleotide base has been substituted for another resulting in a stop codon and frameshift mutations result after a single base is either deleted or inserted which causes the ribosome to read a new set of codons which will alter the complete amino acid chain produced.(see fig,7) All these changes to the DNA sequence will alter the amino acid chain and subsequently have a serious effect on the protein produced and effect how well it will work or how it will carry out a specific task. Gross mutations have the same implications and also experience insertion and deletion but this is of several bases at a time. [14][18] Figure 4: If the number of bases removed or inserted from a segment of DNA is not a multiple of three (a), a different sequence with a different set of reading frames is transcribed to mRNA (b). [19] FIG.7 Frameshift mutations If the number of bases removed or inserted from a segment of DNA is not a multiple of three (a), a different sequence with a different set of reading frames is transcribed to mRNA (b). Identify the genes associated with AI. Faulty alleles of the genes AMELX, MMP20, KLK-4 and ENAM cause the disease amelogenesis imperfecta. These genes usually provide the genetic instructions for the production of proteins that are essential for the healthy formation of enamel. The mutations of these genes have caused a change in the nucleotide base sequence and as a result the protein structure is altered making them work ineffectively or not at all, in turn this has a variety of effects on the enamel formation. [1] The AMELX gene is located on both of the sex chromosomes, X and Y and provides instructions for the protein amelogenin which is essential for normal tooth development as is separates and supports the hydroxyapatite  crystals as they mature. Mutations in AMELX have been found to cause X-linked amelogenesis imperfecta because of the change in structure to amelogenin. [20] The  ENAM  gene provides instructions for the production of the protein enamelin and mutations of this gene can be found in both patients with autosomal dominant AI and autosomal recessive AI.[21] (see below) MMP20  is responsible for the protein enamelysin mutations in this gene are inherited via the autosomal recessive pathway and KLK-4 mutations are responsible for hypomaturation AI. [22][23] Understand and describe the phrases; autosomal dominant inheritance, autosomal recessive inheritance and X-linked recessive inheritance. Humans have 22 pairs of autosomal homologous pairs of chromosomes and one pair of sex chromosomes; X and Y. Females have two X chromosomes where as males have one X and one Y chromosome. [18] There are three patterns of single gene disorders that allow faulty alleles (version) to be passed between generations. These include autosomal dominant, autosomal recessive and X-linked. [14]Autosomal dominant genes [24] FIG.8 Autosomal inheritance In autosomal dominant disorders only one faulty allele needs to be passed from the parents to the offspring for them to be affected by the disease. The affected child will also have one normal allele of the gene making them heterozygous. The affected childrens offspring will also have a 50% chance of inheriting the affected allele. (see fig.8)[14] In autosomal recessive disorders however the likeliness of being affected by the disease is only 25% and both parents must possess at least one of the mutated alleles. (See fig.9)This is because in recessive orders both inherited alleles must be mutants to show an effect in the offspring. There still is a 50% chance of being a carrier (if you have one healthy and one effected allele). [14]http://retinaaustraliansw.com.au/images/AutosomalRecessiveInheritance.gif [26] FIG.9 [26] FIG.10 X-linked inheritance Illustration showing X-linked recessive inheritance pattern with carrier mother In X-linked disorders the faulty allele is present on the X chromosome. As males only have one X chromosome they only need one copy of the allele to have the disease, they are hemizygous. Females however must have two copies of the faulty allele (homozygous) to be affected and so are in most case carriers. A female carrier has a 50% chance of their daughters being carriers and a 50% chance of their sons being affected by the disease. (See fig.10)[18] Amelogenesis imperfecta has different modes of inheritance. Hypoplastic  (Type I) and Hypomaturation (Type II) AI can be inherited by all three modes of the above inheritance patterns. Hypocalcified (Type III) AI is not inherited via the X-linked pathway and Hypoplasia (Type IV) AI is only passed between generations via the autosomal dominant pathway and only one faulty allele has to be passed to the offspring for them to be affected by amelogenesis imperfecta. [13] Conclusion Our nephew has been diagnosed with X-linked amelogenesis imperfecta. Taking in account the above information we can now conclude the reason why he but not his parents are affected by the disease is because our sister must be a carrier of the faulty allele of the gene AMELX. Males are hemizygous so the possibility of the father possesing the faulty allele has been ruled out or he would too be affected by the disease. One can also assume that he is suffering from either hypoplastic AI or hypomaturation AI as the other two types are not inherited via the X-linked pathway. The treatment of amelogenesis imperfecta will depend on the severity of the condition but it is usually to treat the aesthetic symptoms so crowns may be given to hide the displeasing characteristics of the malformed enamel.

The Story of Hala Sultan Tekke :: Cyprus

The Story of Hala Sultan Tekke As the last breath escaped her body and her lifeless gaze fell upon a bright sky, the battle for Cyprus raged on. The donkey, which, up until a moment ago, had been her seat of honor, snuffed at her rumpled hair and then lunged away from her body as the jarring sounds of approaching soldiers drew near. Umm Haram was dead. Umm Haram’s story began in 649 A.D., during the Arab raids for the Mediterranean Sea region in an effort to expand the Muslim empire. Arab Governor of Syria, Moawiya, launched a naval expedition against the Christian Byzantine people living in Cyprus. Under orders from Governor Moawiya and his military officers, Umm Haram was to accompany her husband on this military expedition. After the success of the campaign, they planned to settle and live in Cyprus to expand the Arabian empire. Cypriot legend holds that Umm Haram was an aunt or close friend of the prophet Mohammad. She had followed Mohammed in his Hegira (withdrawal) from Mecca to Medina in September of 622 A.D. Once during a short visit to Umm Haram’s home, Mohammed shared with her a vision from God that the Muslim believers would conquer the Mediterranean Sea region to spread their faith. He also promised her she would be among the first who would fight to conquer the islands. When the time came to join her husband onboard a battle ship bound for Cyprus, Umm Haram remembered the vision the prophet Mohammad had disclosed to her. She was eager to take part in this conquering expedition of Cyprus and to be included as part of a formidable navy. Under Moawaiya’s command, the Arab naval force attacked Cyprus with a massive fleet of 1700 ships. The Arab navy with its powerful ships successfully defeated the forces in Cyprus. Victorious, Umm Haram, with the other conquerors, came ashore and prepared a glorious celebration that included a victory parade, marching into the heart of Cyprus. Because of her assistance in the capture of Cyprus and her relationship to the prophet Mohammad, Umm Haram was given a position of honor and rode a donkey in the parade, while others walked. Unfortunately, as the victory parade progressed inland, the Arab forces were attacked by the Genoese, another marauding group of the Mediterranean region. As the Genoese proceeded with their attack, Umm Haram fell from the donkey she was riding. From the fall she sustained a broken neck and died on the spot from her injures. The Story of Hala Sultan Tekke :: Cyprus The Story of Hala Sultan Tekke As the last breath escaped her body and her lifeless gaze fell upon a bright sky, the battle for Cyprus raged on. The donkey, which, up until a moment ago, had been her seat of honor, snuffed at her rumpled hair and then lunged away from her body as the jarring sounds of approaching soldiers drew near. Umm Haram was dead. Umm Haram’s story began in 649 A.D., during the Arab raids for the Mediterranean Sea region in an effort to expand the Muslim empire. Arab Governor of Syria, Moawiya, launched a naval expedition against the Christian Byzantine people living in Cyprus. Under orders from Governor Moawiya and his military officers, Umm Haram was to accompany her husband on this military expedition. After the success of the campaign, they planned to settle and live in Cyprus to expand the Arabian empire. Cypriot legend holds that Umm Haram was an aunt or close friend of the prophet Mohammad. She had followed Mohammed in his Hegira (withdrawal) from Mecca to Medina in September of 622 A.D. Once during a short visit to Umm Haram’s home, Mohammed shared with her a vision from God that the Muslim believers would conquer the Mediterranean Sea region to spread their faith. He also promised her she would be among the first who would fight to conquer the islands. When the time came to join her husband onboard a battle ship bound for Cyprus, Umm Haram remembered the vision the prophet Mohammad had disclosed to her. She was eager to take part in this conquering expedition of Cyprus and to be included as part of a formidable navy. Under Moawaiya’s command, the Arab naval force attacked Cyprus with a massive fleet of 1700 ships. The Arab navy with its powerful ships successfully defeated the forces in Cyprus. Victorious, Umm Haram, with the other conquerors, came ashore and prepared a glorious celebration that included a victory parade, marching into the heart of Cyprus. Because of her assistance in the capture of Cyprus and her relationship to the prophet Mohammad, Umm Haram was given a position of honor and rode a donkey in the parade, while others walked. Unfortunately, as the victory parade progressed inland, the Arab forces were attacked by the Genoese, another marauding group of the Mediterranean region. As the Genoese proceeded with their attack, Umm Haram fell from the donkey she was riding. From the fall she sustained a broken neck and died on the spot from her injures.