Atomic Number 8 Element Facts

Atomic Number 8 Element Facts Oxygen, element symbol O, is the element that is atomic number 8 on the periodic table. This means every atom of oxygen has 8 protons. Varying the number of electrons forms ions, while altering the number of neutrons makes different isotopes of the element, but the number of protons remains constant. Here is a collection of interesting facts about atomic number 8. Atomic Number 8 Element Facts While oxygen is a colorless gas under ordinary conditions, element 8 is actually quite colorful! Liquid oxygen is blue, while the solid element may be blue, pink, orange, red, black, or even metallic.Oxygen is a nonmetal belonging to the chalcogen group. It is highly reactive and readily forms compounds with other elements. It is found as a pure element in nature as oxygen gas (O2) and ozone (O3). Tetraoxygen (O4) was discovered in 2001. Tetraoxygen is an even more potent oxidizer than dioxygen or trioxygen.Excited oxygen atoms produce the green and red colors of the aurora. Although air consists mainly of nitrogen, atomic number 8 is responsible for most of the colors that we see.Today, oxygen makes up about 21% of the Earths atmosphere. However, air was not always so highly oxygenated! A 2007 NASA-funded study determined oxygen has been present in air for about 2.3 billion to 2.4 billion years, with levels starting to rise 2.5 billion years ago. Photosynthetic organisms, such as pl ants and algae, are responsible for maintaining the high oxygen levels necessary for life. Without photosynthesis, oxygen levels in the atmosphere would fall. Although hydrogen atoms are the most numerous type of atom in the human body, oxygen accounts for about two-thirds of the mass of most living organisms, mainly because cells contain a lot of water. 88.9% of the weight of water comes from oxygen.Swedish pharmacist Carl Wilhelm Scheele, French chemist Antoine Laurent Lavoisier, and British scientists and clergyman Joseph Priestly researched and discovered oxygen between 1770 and 1780. Lavoisier first called element number 8 by the name oxygen in 1777.Oxygen is the third most abundant element in the universe. The element is made by stars around 5x more massive than the Sun when they reach the point where they burn carbon or a combination of helium in carbon in fusion reactions. Over time, the abundance of oxygen in the universe will increase.Until 1961, atomic number 8 was the standard for the atomic weight of the chemical elements. In 1961, the standard was switched over to carbon-12.Its a common misconception that hyperventilation is caused by breathing in too much oxygen. Actually, hyperventilating is caused by exhaling too much carbon dioxide. Although carbon dioxide can be toxic at high levels, its needed in the blood to prevent it from becoming too alkaline. Breathing too quickly causes blood pH to rise, which constricts blood vessels in the brain, leading to headache, slurred speech, dizziness, and other symptoms. Oxygen has many uses. It is used for oxygen therapy and life support systems. It is a common oxidizer and propellant for rockets, welding, cutting, and brazing. Oxygen is used in internal combustion engines. Ozone functions as a natural planetary radiation shield.Pure oxygen is not, in fact, flammable. It is an oxidizer, supporting combustion of flammable materials.Oxygen is paramagnetic. In order words, oxygen is only weakly attracted to a magnet and does not maintain permanent magnetism.Cold water can hold more dissolved oxygen than warm water. The polar oceans contain more dissolved oxygen than equatorial or mid-latitude oceans. Essential Element 8 Information Element Symbol: O State of Matter at Room Temperature: Gas Atomic Weight: 15.9994 Density: 0.001429 grams per cubic centimeter Isotopes: At least 11 isotopes of oxygen exist. 3 are stable. Most Common Isotope: Oxygen-16 (accounts for 99.757% of the natural abundance) Melting Point: -218.79  °C Boiling Point: -182.95  °C Triple Point:  54.361  K, ​0.1463  kPa Oxidation States: 2, 1, -1, 2 Electronegativity: 3.44 (Pauling scale) Ionization Energies: 1st:  1313.9  kJ/mol, 2nd:  3388.3  kJ/mol, 3rd:  5300.5  kJ/mol Covalent Radius: 66 /- 2 pm Van der Waals Radius: 152 pm Crystal Structure: Cubic Magnetic Ordering: Paramagnetic Discovery: Carl Wilhelm Scheele (1771) Named By: Antoine Lavoisier (1777) Further Reading Cacace, Fulvio; de Petris, Giulia; Troiani, Anna (2001). Experimental Detection of Tetraoxygen. Angewandte Chemie International Edition. 40 (21): 4062–65.Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann.Weast, Robert (1984).  CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing.

Gray Seal Facts (Halichoerus grypus)

Gray Seal Facts (Halichoerus grypus) The gray seal (Halichoerus grypus) is an earless or true seal found along North Atlantic coasts. It is called the gray seal in the United States and the grey seal elsewhere. It is also called the Atlantic seal or the horsehead seal, for the males distinctive arched nose. Fast Facts: Gray Seal Scientific Name: Halichoerus grypusCommon Names: Gray seal, grey seal, Atlantic seal, horsehead sealBasic Animal Group: MammalSize: 5 feet 3 inches - 8 feet 10 inchesWeight: 220-880 poundsLifespan: 25-35 yearsDiet: CarnivoreHabitat: North Atlantic coastal watersPopulation: 600,000Conservation Status: Least Concern Description Like other earless seals (family Phocidae), the gray seal has short flippers and lacks external ear flaps. Mature males are much larger than females and have a different coat color. Males average around 8 feet long, but may grow to over 10 feet in length. They weigh up to 880 pounds. Males are dark gray or brownish gray with silver spots. The species scientific name, Halichoerus grypus, means hook-nosed sea pig, and refers to the males long arched nose. Females range from around 5 feet 3 inches to 7 feet 6 inches in length and weigh between 220 and 550 pounds. They have silver-gray fur with dark scattered spots. Pups are born with white fur. The gray seal bull has a distinctive horsehead face. Noemi De La Ville / 500px / Getty Images Habitat and Distribution Gray seals live in the North Atlantic Ocean. There are three large gray seal populations and numerous smaller colonies. The species occurs in great numbers in the coastal waters of Canada south to Massachusetts (with sightings in Cape Hatteras, North Carolina), the Baltic Sea, and the United Kingdom and Ireland. The seals are most often seen when they haul out in winter. They frequent rocky coasts, icebergs, sandbars, and islands. Gray seal distribution. Darekk2 using IUCN Red List data /  Creative Commons Attribution-Share Alike 4.0 International license Diet Seals are carnivores. Gray seals eat fish, squid, octopuses, crustaceans, porpoises, harbor seals, and seabirds. Mature males (bulls) will kill and cannibalize pups of its own species. Gray seals can dive for as long as an hour at depths up to 1,560 feet. They use sight and sound to hunt their prey. Behavior For most of the year, gray seals are solitary or live in small groups. During this time, they rest in open water with only their head and neck exposed to air. They gather on land for mating, pupping, and molting. Reproduction and Offspring Males may breed with several females during the mating season. Gestation lasts 11 months, resulting in the birth of a single pup. Females give birth in March in the Baltic, from December to February in the western Atlantic, and from September to November in the eastern Atlantic. Newborn pups have white fur and weigh around 25 pounds. For 3 weeks, the female nurses her pup and does not hunt. Males do not participate in pup care but may defend females from threats. After this time, the pups molt into their adult coats and head to the sea to learn to hunt. Pup survival rate ranges from 50-85%, depending on weather conditions and prey availability. Females become sexually mature at 4 years of age. Gray seals live between 25 and 35 years. Conservation Status The IUCN classifies the gray seal conservation status as least concern. Although the species was nearly extirpated in the mid-20th century, it began to recover in the 1980s following the passage of the 1972 Marine Mammal Protection Act in the United States and the Conservation of Seals Act 1970 in the United Kingdom (which does not apply to Northern Ireland). Gray seal population size has continued to increase. As of 2016, the population was estimated to be 632,000 gray seals. Some fishermen have called for a cull, believing high seal numbers are at least partly responsible for low fish stocks. Threats Gray seals are legally hunted in Sweden, Finland, and the Baltic Sea. Risks to the seals include entanglement in fishing gear, by-catch, collision with ships, pollution (especially PCBs and DDT), and oil spills. Climate change and severe weather also affect the seals and their prey. Gray Seals and Humans Gray seals do well in captivity and are commonly seen in zoos. They were traditionally popular in circus acts. According to Scottish scholar David Thomson, they gray seal was the basis of the Celtic seal legend of the selchie, a creature that could assume human and seal form. While gray seals frequent inhabited areas, people are advised to avoid feeding or harassing them, as this alters seal behavior and ultimately endangers them. Sources Ailsa j, Hall; Bernie j, Mcconnell; Richard j, Barker. Factors affecting first-year survival in grey seals and their implications for life history strategy. Journal of Animal Ecology. 70: 138–149, 2008. doi:10.1111/j.1365-2656.2001.00468.xBjrvall, A. and S. Ullstrà ¶m. The Mammals of Britain and Europe. London: Croom Helm, 1986.Bowen, D. Halichoerus grypus. The IUCN Red List of Threatened Species 2016: e.T9660A45226042. doi:10.2305/IUCN.UK.2016-1.RLTS.T9660A45226042.enBowen, W.D. and D.B. Siniff. Distribution, population biology, and feeding ecology of marine mammals. In: J.E., Reynolds, III and S.A. Rommel (eds), Biology of Marine Mammals, pp. 423-484. Smithsonian Press, Washington, D.C.. 1999.Wozencraft, W.C. Order Carnivora. In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press, 2005. ISBN 978-0-8018-8221-0.

You are what you eat Research Paper Example | Topics and Well Written Essays - 500 words

You are what you eat - Research Paper Example Ecological footprint calculators ask things such as how much of each kind of meat you might eat in a given week and where do you purchase your food, whether it's at a natural foods store, a local farmer's market or a chain grocery store. Two types of food that can increase your ecological footprint are beef and prepackaged frozen meals. Beef comes from cows and cows hurt the earth in many ways including producing high amounts of methane, polluting freshwater with their excrement, ruining topsoil with their grazing, and requiring a lot of grain to produce the meat we eat. Prepackaged frozen food uses the original resources necessary to create that food to begin with - whether its fish or chicken or vegetables - and then compounds the problem by processing that food for transportation to a manufacturing plant where it is all put together in packages that use more resources and then frozen using more resources. Once everything is ready to be stored, more resources need to be used to kee p the frozen packages frozen as they are shipped to wherever they will be sold, to keep them frozen in the store, and then to keep them frozen in our homes until we're ready to eat them. Then we have to use electricity to heat them and usually end up throwing the packaging away instead of recycling it. To understand this concept better, I chose to analyze the ecological footprint of eating Fritos Bean Dip.

Human Resource Management And Why It Is Critical In Employment Law Essay

Human Resource Management And Why It Is Critical In Employment Law - Essay Example As such, the statute provides that an employee is entitled to a notice period, prior to dismissal. Such notice period is established on the basis of the length of service of the employee (National Employment Rights Authority, 2012). Application An employee has been defined at section 230(1) of the Employment Rights Act 1996, as an individual who works under a contract of employment. The Employment Act 2002 (Dispute Resolution) Regulations 2004 require employers to implement procedures for grievance and disciplinary actions. These statutory procedures have to be commenced in the first instance. This is essential for submitting employment issues before the employment tribunal. A dismissal will be deemed to be unfair, if the employer fails to adopt these procedures (Pothecary Witham Weld, 2012). Furthermore, the employer would be held liable by the court. Employees should have completed a one year of continuous service with the same company to avail the protection of dismissal rights. T his applies only to those employees who were appointed before 6 April 2012. The corresponding period is two years for employees appointed after this date. In our problem, Janice had worked for two years with the same company. Hence, she should have been provided with a dismissal notice, which was not done by the company. Consequently, the dismissal procedures conducted by the company cannot be deemed as fair. Furthermore, in instances, wherein the employer dismisses an employee via procedures that are unfair, the dismissal will be deemed to be unfair, regardless of the issues involved (emplaw, 2012). Although, Kelsey had not completed a year’s period of employment with the company, she can file a claim of wrongful dismissal against the company for not following fair procedures in her dismissal. In general, the circumstances of a particular case, will determine the action that is justified or reasonable, whenever there is a need for formal action. As such, the employment tribu nals will take into account, the size and resources of an employer, at the time of deciding on cases (Code of Practice 1 ACAS Disciplinary and Grievance Procedures, 2009). Under no circumstances, disciplinary or grievance issues should be dealt with in an unfair manner. Moreover, the ACAS has strongly recommended a thorough investigation of allegations by employers. Prior to a disciplinary hearing, particulars of the allegations have to be provided to the employee. In addition, the employee should be provided with an opportunity to explain what had transpired, and to draw attention to any extenuating circumstances (Birkinshaw & Fairclough, 2001). In our problem, Janice and Kelsey were suspected of having stolen a harddisk drive, since it was located in their jointly held locker. They were immediately suspended by the Warehouse Manager, and after two days a disciplinary meeting was conducted and they were dismissed. It is incumbent upon an employer to adhere to a fair process, while addressing a disciplinary or grievance issue. This holds good, even if the employee in question admits to the offense, as also to instances of gross misconduct. In general,

Strategic Decision Making in a Global Business Setting Case Study

Strategic Decision Making in a Global Business Setting - Case Study Example 2. A cultural audit is needed to evaluate these two firms. The audit would evaluate the demographics of the population, education, and experience of the staff. The demographic variables to be judged are age, gender, language and ethnic background. The AMI operation seems to have a deficiency in terms of balance of gender. Only 15% of the worker populations are women. Such an imbalance in gender composition is not healthy and could be used as evidence against the firm if the company ever got into litigation with female workers. AMI also suffer from glass ceiling symptoms since not enough women are part of the managerial staff. The cultural audit performed at UCTC demonstrated that the firm has great diversity within its staff. A good initiative for this firm would be to create seminars and trainings to discuss the importance of diversity and how it can be used as a competitive advantage in the business industry. 3. Due to the differences in culture between the two firms my consulting firm could serve as a valuable intermediary that can create a plan to achieve synergy among the two business entities in the long run. The organizational culture affects the ability of the change agent to incorporate changes (Recklies, 2011). My first action would be to meet with the managerial staff of each company independently.

Business Law Essay Example for Free

Business Law Essay Consideration is an essential element of a valid contract. The four main ingredient of a contract is the offer, the acceptance, the consideration and the intention to create legal relation. Consideration refers to what one party to an agreement is giving or promising in exchange for what is being given or promised by the other contracting party. There are certain rules that govern a valid contract.The issue in the case is whether the agreement was legally binding upon Dream Design or whether it failed for want of consideration. If the promise merely fulfils an existing contractual duty to the promisor, he does not provide consideration to buy the buy promisor’s promise. The baskets were to be delivered by A and a rate was agreed upon between the party. After the first delivery A demanded more money from K before making any further deliveries to W. K unwillingly agreed to pay the extra money and A continued with the delivery. Later on K refused to pay the extra money to A and A sued K. It was held that A had not given consideration to K to buy K’s promise of extra money. A could not say that making the delivery was the consideration, as A was contractually bound to make these deliveries under the original contract. With the case of Dream Design the consideration will not be sufficient where a contractually duty already exist. The fact is that Parma Steel and Dream Design agreed on a written contract dated October 22, 2009 for the supply of fabricated steel at a cost of $165 per ton for â€Å"Grade60,000 and $156 per ton for â€Å"Hard Grade. † In this case Parma Steel could not say that making the deliveries was the consideration, as Parma Steel was already contractually bound to make these deliveries under t he original contract. According to Tucker J. there was no consideration for the new agreement. The plaintiff was already obliged to deliver the defendant goods at the rates agreed under the terms of the original agreement. The facts constituted economic duress but the court has to refuse to enforce the new agreement for the increase in the prices or the higher charges as it lacked any fresh consideration from the purchaser, Dream Design. The supplier, Parma Steel claim for the outstanding balance has to be dismissed.

Prochaska and Di Clemente Stages of Change

Prochaska and Di Clemente Stages of Change The transtheoretical model of change is one of several models of health promotion used by health care professionals in an effort to recognise and foresee health behaviours. The model is supported by various authors as a successful tool and framework within health education. (Warner 2003) This assignment will introduce the model and briefly discuss its input to health promotion together with further developments since its beginning. A concise account of its use in present health education will be given and referred to where applicable. The assignment will go on to discuss the relevance of the transtheoretical model of change within nursing practice and provide an understanding of the model by explaining the main theories. In addition the assignment will discuss and provide further information on what areas impact on how the model is used and why. Further discussion will take account of the strength of the approach used by this model and include theories on why it is used giving consideration to the patient as well as the health care professional. It is recommended that successful health education models can be used to asses goals in order to engage in pre-emptive behaviour and consequently it is crucial that the model is explained in order to take full advantage of its use. (Downie et al. 1997, Ogden 2004) The approach will be investigated in order that the reader can form an opinion on its use and why it is needed within health education. It is acknowledged that nursing and health care practice should be established on the most current and reliable research available and nurses must practice in partnership with equally the patient and other health authorities (NMC 2008). The writer hopes to establish the reader with the necessary information that satisfies these requirements and gives further discussion on how the transtheoretical model of change can be applied to clinical practice. This will include criticisms and challenges against the model and look at how the model is included within broader professional health care such as current health promotion campaigns. Finally a conclusion will be provided which will summarise the findings of this assignment and emphasise any significant features that add to the validity of the model and its use within health care. The transtheoretical model of change was developed by Prochaska and Di Clemente (1983) and grew from systematic integration of more than 300 theories of psychotherapy, along with analysis of the leading theories of behaviour change (Prochaska and Velicer, 1997). Consequently following the inception of public- health programmes this model has been implemented and is used within current health promotion. (Wood 2008) Health promotion is defined by the World Health Organisation (WHO 1986) as the process of enabling people to increase control over, and to improve, their health. Health education is considered an approach of health promotion which also includes many theories, beliefs and concepts in regards to effective intervention. (Tones 2001) The transtheoretical model of change focuses on the decision-making abilities of the individual rather than the social and biological influences on behaviour as other approaches tried (Velicer, Prochaska, Fava, Norman, and Redding, 1998; Scholl, 2002). This model was developed to provide a framework for understanding how individuals change their behaviours and for considering how ready they are to change their substance use or other lifestyle behaviour. The stages and processes by which people change seem to be the same with or without treatment these include the individuals perceptions of susceptibility to illness, severity of illness, barriers to changing behaviour, benefits to changing behaviour and finally action and maintenance. Although the model has been adapted and modified to include further components for the purpose of this assignment it is necessary to explain the theory behind the original before discussing modifications. (Ogden 2004, Bennett and Murphy 1997, Naidoo and Wills 2000) In addition it is suggested that by using these concepts in the transtheoretical model of change it will predict the likelihood that behaviour will or will not change depending on the individuals perception. The idea of anticipating behaviour and therefore adjusting intervention is supported by various researchers who suggest that using cognitive models can assist in how individuals perceive health by conscious thought as to the behaviours and the cost of those behaviours. (Yarbrough and Braden 2001, Roden 2004a, Wood 2008) This supports healthcare professionals to allow the patient to change behaviours based on their own awareness as opposed to medical tactics to health promotion that have been used previously. Ewles and Simnett (2003) recommend that using a client centred approach empowers the patient to change behaviour and independently manage behaviour and as a result the health care professional becomes a facilitator instead of an instructor. Using a client centred approach does not discount the benefits of the medical approach as it may require various tactics depending at what stage of the model the individual is identified as being at. However by using an effective health promotion model, it encourages the patient to become an active participant and more responsible for their health related decisions. Ogden (2004) describes the concept of an individuals perception of control on their health as the Health locus of control which will be discussed later within this assignment. Based on the understanding of individual perceptions influencing behaviour it reinforces the use of the components previously discussed and by looking at these separately it is hoped that health care professionals will be able to detect the risks of behaviour and the probability of change. (Naidoo and Wills 2000, Ogden 2004) The previous mentioned components can be identified in the Transtheoretical model of change; these include pre-contemplation, contemplation, action, and maintenance. However the aspect that makes the transtheoretical model of change unique is the theory that change occurs over time, an aspect generally ignored by other models of change (Prochaska and Velicer, 1997; Velicer et al., 1998; Scholl, 2002). This temporal dimension of the theory suggests that an individual may progress through five stages of change when trying to adjust their behaviours (Prochaska and Di Clemente, 1983; Prochaska et al., 1992; Prochaska and Velicer, 1997). In the transtheoretical model of change, behaviour change is treated as dynamic, rather than an all or nothing phenomenon. This distinction is considered one of the theorys strengths (Marshall and Biddle, 2001). The first stage of change within the transtheoretical model of change is the precontemplation stage, where individuals have no intention of taking action within the next six months (Prochaska et al., 1992; Prochaska and Velicer, 1997; Scholl, 2002). Individuals at this stage may or may not be aware of the consequences of their behaviour (Prochaska et al., 1992;Scholl, 2002) or may have tried to modify/change their behaviour and failed several times and as a consequence are dejected and unwilling to have another attempt (Prochaska and Velicer, 1997). Prochaska et al (1992) propose that the main characteristic of someone in the precontemplation stage is that they struggle to accept that they have problem behaviour and as such they cannot move on from this particular stage of the model. In order for the individual to move on they must experience cognitive dissonance which is acknowledging that there are negative aspects to continuing with this behaviour (i.e. smoking and the possibility of contracting lung cancer as a result) (Scholl, 2002). Following on from precontemplation, contemplation is the individual trying to make significant changes within another six month period, this includes evaluating any benefits or disadvantages to the individual changing their behaviour (i.e. cost of smoking, as opposed to loss of social activity) as a consequence many people stay within this stage for longer (Patten et al., 2000; Prochaska et al., 1992; Prochaska Velicer, 1997; Velicer, 1997; Velicer et al., 1998). Therefore the behaviour may seem more attractive than the change needed to be made (Scholl, 2002). This is known as chronic contemplation or behavioural procrastination (Prochaska and Velicer, 1997). Whilst within this phase the individual will still continue with the risky behaviour despite being aware of the consequences that this behaviour could cause (Patten et al., 2000). However it is widely accepted that someone within the contemplation stage is genuinely trying to resolve their problem behaviour (Prochaska et al., 1992) and as a result will only move on to the next stage when the positive aspects of change outweigh the negative aspects of remaining the same (Scholl, 2002). Preparation proceeds contemplation and in this area of change the time scale for the individual to modify their behaviour reduces to within the next month (Patten et al., 2000; Prochaska et al., 1992; Prochaska and Velicer, 1997; Velicer et al., 1998). An individual in this stage has tried to change or adjust their behaviour within the last year and has been unsuccessful however this has not discouraged them from continuing to i.e. binge drinking, smoking, or misuse of drugs. As a result of this the individual is at a loss as to how to proceed with any changes and if they are ultimately able to make these changes given that they have up until now failed (Scholl 2002). In this instance a plan of action can be produced by the healthcare professional in order to identify how to reduce or eliminate the problem behaviour and therefore give the person the opportunity to choose between alternative solutions i.e. smoking 10 cigarettes as opposed to 40 cigarettes a day or to stop smoking with the help of nicotine patches (Prochaska et al., 1992; Prochaska and Velicer, 1997; Velicer et al., 1998). Consequently when an individual feels confident and in control of the situation and has identified a suitable plan of action they will naturally move on to the next stage of the model (Scholl, 2002). The action stage follows on from preparation and as a result efforts have been made to adjust the individuals, behaviours, experiences, or environments over the previous six months in order to conquer their predicament. This stage requires a considerable amount of time and energy and is the stage where the individual receives the most amount of attention from others because of their obvious hard work (Patten et al., 2000; Prochaska et al., 1992). However it should be noted that research has stated not to mistake trying to change with actual change, this only occurs when the criteria is reached for the individual and will reduce the risks associated with their particular problem behaviour (Prochaska et al., 1992; Prochaska and Velicer, 1997; Velicer et al., 1998). Prochaska, DiClemente, and Norcross (1992) suggest that the main ways of identifying a person within the action stage is by the individuals obvious lifestyle changes i.e. healthy eating and documented weight loss to a more acceptable criterion level. Progress into the final stage happens when the individual perceives positive changes to their lifestyle, health and as a result feels better whilst also receiving encouraging feedback from family, friends and health professionals (Scholl, 2002). Lastly the transtheoretical models maintenance stage is where people work to prevent a relapse and only after six months of being free of the problem behaviour can it be recognised as the criteria of an individual being within the maintenance phase. Research also recognises that maintenance is a continuation of change not an absence of it (Patten et al., 2000; Prochaska et al., 1992; Prochaska and Velicer, 1997; Velicer et al., 1998). Consequently individual perception is referred to the threat of illness and modifying factors can be referred to as behavioural response. In addition the likelihood of action is influenced by environmental cues. As a result the behaviour change occurs because of a threat to illness and therefore the behaviour changes or is adapted. Mc Clanahan et al. (2007), Warner (2003) and Clark (2000) all describe the threat as an individuals susceptibility to illness or disease. If an individual believes they are open to the illness or disease they may identify this as a danger to their health. This is only applicable if there is a significant risk factor such as smoking, diet, alcohol or drugs misuse. If an individual does not take into consideration their own vulnerability then it is unlikely that the transtheoretical model of change will be successful in predicting associated behaviour. Ogden (2004) suggests that perceived susceptibility can not be used as an effective predictor of behaviour change. Furthermore consideration must be applied to adolescents who are more likely to expose themselves to risks but be less aware of the consequences to their associated health. Naidoo and Wills (2000) suggest that health promotion can be challenging when dealing with young people in regards to risk behaviour as risk taking is essentially a part of adolescence. On the other hand it is usually accepted that if an individual perceives themselves to be vulnerable to a disease (i.e. lung disease from smoking) they will also consider the severity of that disease. (Daddario 2007, Simsekoglu and Lajunen 2007) The perception of severity or seriousness of a disease is subjective depending on the individuals understanding of the potential threat. Browes (2006) refers to the variance of perceived severity in relation to sexual health. The severity can vary from the belief that most diseases can be treated to the belief that sex can result in contracting potentially fatal diseases such as HIV. Therefore it may be necessary for the health care professional to encourage learning in relation to the severity of conditions in relation to the susceptibility. Finfgeld et al (2003) outline that to facilitate learning effectively it may be necessary for the health care professional to apply a more direct attitude which would involve the nurse addressing the increase of behaviour (susceptibility) as well as identifying potential risks (severity). However with this intervention the approach becomes nurse led as opposed to patient led which may compromise empowerment and likelihood that risk behaviour will return when the intervention is reduced. As a result the delivery of the necessary information to the patient may result in feeling of fear or guilt. Although it is suggested that fear and guilt can be effective in changing behaviours , it is criticised as it does not change behaviour long term and can contribute to feelings of denial and therefore affect the relationship between both patient and healthcare professional. (Naidoo and Wills 2000) Based on perceived susceptibility and severity the transtheoretical model of change believes that behaviour change will take place if the benefits outweigh the barriers to changing behaviours. However it is expected that potential benefits may be small compared to the barriers that prevent changes to behaviour. (Daddario 2007) Then again as previously discussed the transtheoretical model of change has had several modifications made to it in order to maximise its use within healthcare in order to apply it to other more complex health conditions. The psychologists who developed the stages of change theory in 1982 did so in order to compare smokers in therapy and self-changers along a behaviour change continuum. The idea behind this was to allow health care professionals to adapt a plan of action for each individual and as a result their therapy would be tailored to their particular needs. This process was then added to by a fifth component (preparation for action) as well as ten processes that help predict and motivate individual movement across the stages of the continuum. In addition, the stages are no longer considered to be linear; but are components of a cyclical process that varies for each individual (Diclemente and Norcross 1992). Used correctly and by incorporating the various modifications to the model, it is recognised that the transtheoretical model of change can assist health care professionals in health education. However as a psychological theory, the stages of change focuses on the individual without assessing the role those structural and environmental issues may have on an individuals ability to enact behaviour change. In addition, since the stages of change presents a descriptive rather than a causative explanation of behaviour, the relationship between stages is not always clear. Consequently each stage of change may not be appropriate for characterising every population. An example of this would be the study of sex workers in Bolivia which highlighted that very few of the participants were actually in the precontemplative, contemplative stages with regards to using condoms with their clients (Posner, 1995). However mass media campaigns can motivate individuals to change behaviours by highlighting the benefits of safer sex by the use of condoms. The use of positive messages as opposed to negative messages within mass media campaigns increases the likelihood of retaining the relevant information for longer. (Bennett and Murphy 1997) Naidoo and Wills (2000) also suggest individuals may have personal experiences of illness and disease within their family or friend network therefore this will influence how the benefits are perceived.These modifying factors will influence the likelihood of action and therefore determine if behaviour will change. As a result research conducted by Charron-Prochonwnik et al. (2001) found that changes to individual sexual behaviour correlated to the consideration of modifying factors such as social support, culture and positive attitudes resulting in safer behaviour. Additionally there are other features of the Transtheoretical Model of Change that are not easily applied to non-addiction type clinical problems. Howarth (1999) noted that the application of Transtheoretical Model of Change has promise in the field of eating behaviours but the translation is made difficult because the goal of smoking intervention is cessation whereas eating interventions is reducing intake of some foods and increasing the intake of others. Also in smoking interventions the main aim is to stop and is clearly understood by everyone. However in eating interventions the main aims are not so easily understood. Whereas in smoking research the outcome variables are reasonably simple compared to eating research where outcomes are more complex and the results variable. Ultimately smoking interventions target one behaviour whereas eating interventions focus on multiple behaviours. Furthermore there is the degree of difficulty in discontinuing smoking in the initial stages but as time progresses things get easier for the individual whereas eating more healthily can be easy at first but hard to maintain. Moreover when smoking discontinues it produces immediate physiological changes but eating interventions in the early stages only produce distant and subtle changes. As a result behaviour change will not only be on the basis of potential benefits but may also be subject to internal and external cues. As previously mentioned campaigns can promote changes to behaviour and this would be considered an external cue, the individual is motivated by the message that is projected. (Naidoo and Wills 2000) However internal cues may also influence behaviour, this may be a change in physical health or psychological wellbeing which encourages the individual to ask for help from health care professionals. Daddario (2007) suggest that internal cues are most likely to change behaviour in individuals that are over weight. Clarke et al, (2000) further suggest that with the incorporation of self-efficacy, health models can be more effective in predicting behaviours; this concept was developed by Bandura (1977) and can be described as an individuals confidence in their ability to complete a task. Finfgeld et al. (2003) also acknowledge that nurses can promote self-efficacy alongside models of health by reinforcing the importance of the contribution of individual capability in changing behaviours and can be used within educational and client centred approach to health education. In addition to self-efficacy Hughes (2004) considers the concept locus of control in order to maximise the use of various models of health. Locus of control refers to how the individual perceives control over their life and physical health. An individuals beliefs may be based on the idea that their health is subject to internal actions such as diet, lifestyle and as a result able to be changed. However in contrast others may believe that health is subject to external factors such as bad luck or fate. Just as important is the belief that religion and culture can contribute to the belief that health is predetermined and therefore cannot be influenced by behaviour changes. (Niven 1994, Naidoo and Wills 2000) Consequently Syx (2008) suggests effective questioning technique to establish where an individual places the locus of control, which should then determine how likely they are to engage in health education behaviours. In conclusion despite conflicting evidence for the transtheoretical model of change Macnee McCabe (2004) do not have conceptual concerns regarding this, but question the applicability of the model to specific populations. Sutton (2001) also suggests that there are some serious problems with the existing methods used to measure the stages of change. For example, stage criteria are not consistent across studies that use the approach. Some studies do not include questions about past attempts to change, and various time frames are used as reference points which alter distribution of people across stages (Lerner, 1990; Nigg et al., 1999; Stevens Estrada, 1996; Weinstein et al., 1998). Finally, Littell and Girvan (2002) suggest that a continuous model of readiness for change may be more integrated with related concepts from other theories. It is also documented that healthcare professionals be able to distinguish readiness for change from readiness to participate in particular treatments, and that change may come about quickly as a result of life events, or external pressures. Accordingly at this time there is an increase in the number of studies criticising the model over conceptual, methodological analytic concerns. On the other hand there is an equal amount of evidence supporting the model, verifying the constructs, and showing support for application to modifying health behaviour. Therefore the benefit of understanding this model and maximising it to its full potential can support nurses and other health care professionals to practice in accordance to guidelines set out by both clinical and academic bodies. 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