Essay --

Homeostasis in Zostera marina (Eelgrass) Homeostasis, what is it? Homeostasis is the balance between systems to keep living organisms alive and healthy. For an organism to maintain homeostasis its body systems must react and respond to changes in both its internal and external environments. Majority of body systems in organisms, like a respiratory or circulatory system in animals, are part of their internal environment. One body system that is very important for maintaining homeostasis and is common among many organisms is a respiratory system. The respiratory system is responsible for disposing of carbon dioxide and in taking oxygen (vice versa for plants). Some parts that make up a respiratory system are the lungs, windpipe, and cilia in animals. Another body system important to homeostasis and common among animals is a circulatory system, used for bringing nutrients like glucose and oxygen to body cells. Some parts that make up a circulatory system are a heart, blood, and tubes for the blood to travel through (veins, art eries, and capillaries) in animals. There are many more body systems important to homeostasis, but if one is disrupted it’s vital for it to be restored to normal. It is very important for organisms to maintain homeostasis because when it’s disrupted that could cause other systems to go out of balance, which may result in damage in the organism. Homeostasis can be disrupted in many ways like when a human is sick. When a human is sick it starts in the immune system and depending on the intensity of the sickness it can cause other things like water balance and body temperature to go awry which would affect other systems. Another scenario when homeostasis is disrupted is when a plants water level is low and it wilts... ...hroughout the Eelgrass. Excess water in the form of vapor is disposed of through stomata on the leaves. The gas exchange, root, and shoot systems are used in this exchange because the stomata release the excess water in the form of water vapor, which was first absorbed by the roots in the root system, then transported through the xylem in the shoot system throughout the eelgrass. Another exchange that goes on in Eelgrass is nutrients to plant cells. Again the gas exchange, root, and shoot systems are used. Nutrients are absorbed by the roots and made through photosynthesis; stomata take in carbon dioxide which is used along with light, water, and other nutrients previously stored to make more. Nutrients are carried throughout the plant to plant cells by the phloem. Homeostasis is the balance of systems in organisms and it’s very important to keep them in balance.

Life and works of John Steinnbeck Essay example -- biographies bio bio

John Steinbeck was probably the best author of all time. He was the winner of a Nobel Prize, and along with many other accomplishments, Steinbeck wrote twenty-five books, including sixteen novels, six non-fiction books and several collections of short stories during his lifetime. Seventeen of his works, including The Grapes of Wrath, Cannery Row, The Pearl, and East of Eden, went on to become Hollywood films, some appeared multiple times, as remakes. Steinbeck also had some success as a Hollywood writer, receiving an Academy Award nomination for Best Story in 1944 for Alfred Hitchcock's Lifeboat. Many of his life experiences are shown through his novels. Someone can tell, by reading one of Steinbeck’s novels that he had been through a lot, throughout his life. Also, Steinbeck worked hard to accomplish everything that he did, during his lifetime. Nothing came easy for him, and had to earn everything on his own, and this helped him in his works. He also had the ability to write about real people and real experiences. John Steinbeck got his inspiration from his life experiences such as people he knew, and places he had spent time at. Many of Steinbeck's views of the world are shown through his novels. Some of Steinbeck’s most influential works are included in this paper and are summarized, to show how many Americans living in poverty today can relate to some of Steinbeck’s works which are also set during a recession era. Growing up in Salinas Valley, Steinbeck had the chance to spend a lot of time outdoors. His uncle used to take him on fishing trips, and spent time visiting his mother’s grand-fathers' farm near King City, it gave him a large respect for nature. Later on he became a caretaker on a large piece of land at Lake Tahoe, ... ...life experiences, events, and people which makes it easier for the reader to connect if they too had the same experiences first-hand. Although John Steinbeck has been gone for awhile, his legacy continues to thrive on Americans today. Steinbeck’s influence not only flourishes across the United States but has also been all around the world. His influnces have also attracted the attention of film production studios in which the have created movies based upon stories from Steinbeck. His legacy is also continued through high school reading, a study by the Center for the Learning and Teaching of Literature in the United States found that Of Mice and Men was one of the ten most often read books in public high and independent schools. Steinbeck has been honored in many ways having, places dedicated to him and having his name inducted into the California Hall of Fame.

Character Building †Forgiveness Essay

Forgiveness; it’s not something people often think about. It’s also not something highly publicized. However, it is hugely important. Forgiving others and being forgiven, impacts our whole lives. Forgiveness can impact your health, your happiness, your relationships, and more. Forgiveness is something all parents need to be sure to take the time to teach their children. Parents are the first line of defense when it comes to children. They may not always listen or grow up remembering and abiding by the morals and ethics you tried to teach them, but a lot of the time they do. I define forgiveness as the letting go of anger, hurt, and hate towards a person (or people) who has wronged or harmed you physically, mentally, or emotionally. Refusing to forgive someone has several repercussions. To begin with, withholding forgiveness can actually harm you physically. By refusing to forgive someone, you are not allowing yourself to heal and move on. In response, you body turns that anger and resentment into stress, high blood pressure, lower immunity, anxiety, and even depression (Mayo Clinic staff, 2011). That same anger can also make you bitter. You will begin to be angry with everyone, you won’t be able to enjoy the present, you life could begin to lack meaning and purpose, make you at odds with your spiritual beliefs, and cause you to lose your connection with others (Mayo Clinic staff, 2011). You have to be careful with your anger so you don’t hurt others around you. You could be threatening your relationships with those you love. If you’re acting like a jerk to those around you, relational interdependence could decrease due to the way you treat them. Also, due to social exchange, they may treat you the way you are treating them. Creating more hate and hurt for you and just making your already bad situation worse. Not forgiving also makes you just as bad as the person who hurt you. The longer you hold onto your anger, the more you will desire revenge. Revenge makes you your worst self and puts you on the same level as that person you hate (Orloff, 2011). This could also be referred to as cognitive dissonance. You believe that it is wrong to hate or hurt someone, yet you are unwilling to forgive the person who has harmed you. The best place for forgiveness to start is with parents. Parents need to start teaching their children about forgiveness in a way they can understand at as young an age as possible. The sooner they are exposed to forgiveness, the more likely they are to retain it, even if they don’t fully understand it yet. A perfect way for parents to teach this to their children is through example. Children are very impressionable and want to be just like their parents when they are young. They will imitate what they have seen. The more the parent demonstrates forgiveness, the more likely the child will remember it as they get older. Being a good example is also a good way to prime your child to forgiveness. If they see it all the time, they are more likely to react in a similar fashion. In my opinion, you cannot talk to your children enough. Talk to them about everything, even if you have to take the time to put it into context that they can understand. Answer all their questions as best as you can. Children will remember. Even better, as they age, your child will continue to come to you to talk if you are always open and available to them. Being an example also applies to any other adult in a child’s life that has contact with them; teachers, coaches, relatives, etc. Forgiveness begins at home. It is very easy to think of a time when you needed to forgive someone. A good example is being out somewhere and having some stranger with whom you have contact who is rude, short, or angry with you. It is natural to feel angry at them for lashing out at your for no reason, but you must forgive them all the same. You have no idea what they are going through. You must remember to have compassion and empathy. They could be severely stressed out, or had someone lash out at them for no apparent reason; and since they did not forgive, they continued to harbor and pass along that anger. Do not allow yourself to be a conduit for negative energy. If you forgive them, which doesn’t mean you say it to them, but inwardly, you will be less stressed yourself and happier than if you had held on to something so menial. Another example, though not so insignificant, is that of childhood abuse. This is a topic I can speak on directly. I cannot stress it enough, you CANNOT hold on to your anger at the person who harmed you. The only person you will hurt is yourself (Creates Personal Growth, 2008). If you allow yourself to forgive them, you can start your healing process and be able to move forward with your life (Creates Personal Growth, 2008). You will also be more apt to have healthier relationships in your life. My abuse was of a sexual nature. I forgave the perpetrator many years ago, and thus far I have had no problems in relationships myself. If you, however, chose to not forgive, but harbor that hate, you will forever be a ‘victim’ in life. You will struggle in many things and build negativity in relationships throughout your lifetime (Wilner, 2011). Forgiving is not always easy, but it must be done. Forgiving does not mean forgetting, nor does it mean denying the other person’s responsibility for hurting you or justifying the wrong (Mayo Clinic staff, 2011). You can, however, forgive the person without excusing the act because forgiveness refers to the actor not the act (Orloff, 2011). You must forgive them for their conscious or unconscious suffering that motivates them to act the way they do. Forgiveness can be especially difficult if the person who hurt you doesn’t admit to their wrong or apologize (Mayo Clinic staff, 2011). Unfortunately, forgiving does not always make the person change their actions or behavior, but it does change your life. Forgiving will give you peace, joy, and healing, and remove any power the person who harmed you had over you. Additionally, if you believe in karma or reciprocity, it makes it easier to forgive. Knowing that even though they may still be doing wrong to you or others, but that you have forgiven them, it is no longer in your hands. It is up to the universe to decide how they and you will be rewarded or punished. Today’s society does not bode well for teaching forgiveness. I can personally think of no kids’ TV shows, cartoons, or movies that teach or display forgiveness. Also, the media tends to show bad examples more than good, reporting focuses more on the negative than the positive in most cases. In general, ‘victims’ get more attention than someone who has gone past the wrong and moved on with their life. By being the victim, they have no responsibility to uphold, and if they do chose to forgive, they become responsible for how they carry on afterwards. Forgiveness is considered weak, and justice strong. Everyone knows the old saying â€Å"an eye for an eye† but as well all know, that â€Å"only makes the whole world blind.† And yet, many religions preach the ‘eye for an eye’ view over unconditional love for others and forgiveness. There is also the old quote â€Å"don’t get mad, get even† that many people know. There are so many proverbs like these that come to mind so easily. Ones about forgiveness are much rarer. I would like to conclude with 7 simple steps for forgiveness and a thought. The steps spell out â€Å"forgive† and are easy to remember: Face the facts, Oust the anger, Remember the offenses, Give benefit of the doubt, Imagine what forgiveness feels like, Value the experience, and Embrace forgiveness (Bennett). Now for my thought, God gave us a great example of love and forgiveness when he put dogs on this earth. Dogs are one of the few creatures who know how to love unconditionally. People think they do/can, but they don’t. Dogs will continue to love their owners/masters even if they are neglected, misused, abused, and beaten. It takes a lot for a dog to start to hate their owners. Almost no matter what you do to them, they will still cower at your feet and try to show you how much they love you. I wish people could be more like dogs. â€Å"Scars remind us where we have been, they don’t have to dictate where we are going.† -Author Unknown References Bennett, C. (n.d.). 7 Simple Steps to Forgive Others & Yourself – Mind, Body, & Soul at Exploring Womanhood. Exploring Womanhood. Retrieved April 30, 2012, from http://www.exploringwomanhood.com/mindbodysoul/forgive.htm Creates Personal Growth. (2008, September 11). The Most Important Reason Why You Ought To Forgive | Creates Personal Growth.com. Creates Personal Growth. Retrieved April 30, 2012, from http://www.createspersonalgrowth.com/335/why-you-should-forgive/ Mayo Clinic staff. (2011, November 24). Forgiveness: Letting go of grudges and bitterness – MayoClinic.com. Mayo Clinic. Retrieved May 2, 2012, from http://www.mayoclinic.com/health/forgiveness/MH00131 Orloff, J. (2011, September 8). The Power of Forgiveness: Why Revenge Doesn’t Work | Psychology Today. Psychology Today: Health, Help, Happiness + Find a Therapist. Retrieved May 2, 2012, from http://www.psychologytoday.com/blog/emotional-freedom/201109/the-power-forgiveness-even-911 Wilner, J. (2011, August 21). Why Forgiveness is Major Key in Relationship Success | Adventures in Positive Psychology. Psych Central Blogs. Retrieved May 2, 2012, from http://blogs.psychcentral.com/positive-psychology/2011/08/why-forgiveness-is-major-key-in-relationship-success/

Home Video Game

1: Why the rapid growth of Atari? Why the 1982-85 collapse? How did Nintendo rebuild the industry? What was its strategy? After Bushnell settled on Atari, his first built was the simplest game, which people knew the rules immediately, and this game could be played with only one hand. Then, Bushnell talked his way into a $ 50000 line of credit from a local bank to start his business. By 1974, 100,000 Pong-like games were sold worldwide, and although Atari manufactured only 10 percent of the game, the company still made $3. 2 million that year. Atari had a rapid growth because it is a new industry, and Atari does not have any competitor at that time. So, Atari is the only company in this home video game industry, and it has a huge power of supplier with no competitors and substitutes. After 1976, about twenty different companies were crowding into the home videogame market, Atari still has more than 50% market share in the industry. Until 1978, Atari estimated that total demand would reach 2 million units. In 1982, Atari lost $500 in the first nine months of the year. Part of the blame for the collapse was laid at the feet of an enormous inventory overhang of unsold games. With more and more new games hit the market, the average price would goes down and the profits goes down as well. Nintendo established a commanding worldwide position by the end of the decade. The first step of Nintendo was to license video game technology from Magnavox. Then, Nintendo tried to develop its own video game machine (Famicom) that combined superior graphics processing capabilities and low cost. In the US, Nintendo established a subsidiary named as Nintendo of America (NOA) by 1980, and Nintendo repositioned the market in U. S. NOA spent about 2% of sales budget for advertising and also sought out promotion partner, and it practiced careful inventory management in releasing its new games. In conclusion, Nintendo made an innovative new game system which had some competitive advantages such as cheaper, superior image quality, faster hardware processing and a connector that can be used for future addition of a modem and keyboard. : How was Nintendo able to capture value from the home video game business? First of all, with the video game industry’s collapse, none of the company seems to have anything to do with the with the home video business except Nintendo. So, it was a big chance for Nintendo to monopolize the video game business, and it was a good chance to negotiate and license other companies to develop games for its system. Secondly, Nintendo has good market posi tion and distribution in United Stated. Thirdly, Nintendo has good game designing and technology, and it uses the regulation, contract and patent license to limit the market share of other game companies. 3: How was Sega able to gain market share from Nintendo? With Sega’s first game Periscope, Sega built up a respectable export business. Then, Sega realized that great games drove sales and more powerful technology gave game developers the tools to develop more appealing games. Sega also licensed other companies to develop games for the Genesis platform, but asked for lower royalty rates than Nintendo. Despite aggressive marketing in the 80s, it wasn't until the introduction of Sonic the Hedgehog in 1991 as a direct competitor to Nintendo's Mario character that Sega was able to capture a meaningful amount of the market with its Genesis console. The key point was Genesis does what Nintendo don’t, and Sega version out sold Nintendo’s two to one. 4: Evaluate the competitive strategy of 3DO. What flaws can you see in 3DO’s approach? The vision for 3DO was to shift the home video game business away from the existing cartridge-based format and toward a CD-ROM-based platform. The belief at 3DO is that the superior storage and graphics processing capabilities of the 3DO system would prove very attractive to game developers, allowing them to be far more creative. In turn, better games would attract customers away from Nintendo and Sega. The 3DO’s strategy was to license its hardware technology for free. However, only a few 3DO titles were available by the Christmas period where reports suggested 150 titles, and sales of the hardware were slow. As can be seen, 3DO did good at its software, but bad at its hardware. As a result, 3DO announced that it would either sell its hardware system or move into joint venture. 5: How come the Sony Play Station has succeeded where 3DO failed? Sony set up a retail channel separate from its consumer electronics sales force, and Sony has a good communication with retailers before the launch to find out how it could help them sell the play station. Sony targets its advertising for PlayStation at specific generation and age range. So, Sony focused on it retailers and customers, and it has a good market position. On the other side, 3DO only focused on its products but lack of the communication with its retailers and customers. 6: What drove Microsoft’s decision to enter the industry with its X-box offering? Because before Microsoft entered the home video game industry, it was no stranger to games. Microsoft had long participated in the PC gaming industry and was one of the largest publishers of PC games. X-box was based on Microsoft’s PC technology, and it would be much easier for software developers to write game for. Microsoft enter the industry because with annual revenues in excess of $20 billion worldwide, the home video game industry is huge and an important source of potential growth for Microsoft. 7: What lessons can be learned from the history of the home video game industry that has been used to help launch the Sony PlayStation II and Microsoft’s X-Box? Do Microsoft and Sony appear to have learned and applied these lessons? The lesson can be learned from the history of the home video industry was to focus on R&D, market positioning, cost leadership, innovation, technology and communications. Sony PlayStation II has consumed about 1. 3 billion in R&D, and Sony actually loses money on Sony PlayStation machine but gain from game CDs. On the other side, Microsoft’s X-Box cut X-box price over time but guaranteed a profit margin. There are three technical factors determined the quality of a video game: data width (in bits), clock speed (in MHz), and the amount of RAM (in bytes). Both Sony PlayStation II and Microsoft’s X-Box have their own competitive advantage in these technologies, and they also both are good game designers.

Technology Is Being Used Increasingly in the

Argumentative Essay Writing Tips Find your topic – From abortion to human trafficking, the sky is the limit when it comes to finding a heated topic to present an argument about. Think about your stance – Are you going to be for or against human trafficking? Logically, most people would be against human trafficking but either way you will need to be confident and comfortable in whatever stance you take. Additionally, you will need to be able to substantiate the facts and cleverly fuse them with your stance in order to arrive at a solid argumentative essay. This will require that you think about your stance on the issue essay writers world reviews.Think long and hard in order to better be able to discern where you are trying to take the topic argumentatively. Do your homework – There have undoubtedly been others who have argued for or against the topic that you chose who may have done it years prior to you even thinking about it. Take time out to research how your predecessors argued their stance. This is not to say that you should mirror that stance, but it might give you a heads up and/or better tips on what direction you should be moving towards when it comes to the ebb and the flow of the argument.Know your opposition – Every argumentative topic has a pro side and an opposing side. The best possible strategy that you can employ when writing the article is to know your opponent’s stance on the issue. When you know how your opponent will think or what rebuttal he or she will try to use, then you will have an upper hand on how to out debate them. Knowing your opponent is essential in counter-attacking when it comes to your argumentative essay. Get the facts – What good is an argumentative essay if there are no facts? The bottom line is that you need facts in order to support your argument on your controversial topic.No one wants to look like an amateur, and in order to avoid doing such you will need to have cognitive and verifiable facts that will back up your argument completely. Without these facts your risk looking both unprofessional and unprepared. Pick a topic that you are passionate about – When there is no passion in an argumentative essay then there is nothing to capture the attention of the reader. In order to convey your argument it is imperative for you to be passionate about any topic that you pick. If you do not believe in it then no one else will either. Steps in writing your Essay INTRODUCTION 1.Paraphrase the question 2. State your position [totally/strongly/somewhat + agree/disagree] BODY 3. Write topic sentences for each body paragraph Sequencing word + topic + point The main reason why I believe teachers are necessary is because they are essential for disciplining and motivating students CONCLUSION 4. Summarise main points 5. Give your final opinion or recommendation/ restate your position A Sample of Argumentative Essay Technology is being used increasingly in the classr oom and some people believe that educators will become redundant. I somewhat disagree that teachers will be replaced by machines.The main reason why I think that teachers are essential is because they encourage and discipline students. Many people find it difficult to be interested in learning new things. Therefore educators are needed to make classes more interesting and stimulate students’ desires for learning. Also, in the case of young people, teachers often need to force students to learn through the use of punishments. Another reason why teachers are needed is because they can teach young people important skills and values. This is because educators serve as role models to their students and teach them how to appropriately interact with their peers.Therefore, if people only learn using machines they will lose the opportunity to learn important social skills and values. However, studying over the internet certainly offers a lot of convenience. First, we are able to study in the comfort of our own homes, without the need to commute to school. Second, we can choose to study at any time we like even in the middle of the night. In summary, I somewhat disagree that machines can replace teachers. This is because teachers can encourage students to learn and teach them how to interact with other people. Although, computers do offer the ability for people to learn anywhere at any time.

Application Of Driver State Monitoring Systems (Dms)

Application Of Driver State Monitoring Systems (Dms) The term ‘driver state’ has no specific universal definition and is loosely used in the fields of Psychology and Engineering. In general, driver state refers to a set of conditions that affect the driver in a specific instance. Drivers in an optimal state do not suffer from any condition. Vehicle control transition is very important for the success of Highly Automated Driving (HAD). In an ideal scenario, human driver will be attentive to the Driving scene during Take Over Request (TOR). Recent advancements, along with higher levels of automation has made it possible for the driver to be in distracted, inattentive, or even fatigued state. Under similar driving scenario and automation behavior, a driver with some sort of impairment will have poorer performance tackling the situation than when in ideal state. Researches showed that distracted drivers had higher difficulty to adjust speed to a critical event than attentive drivers. Driver State Monitoring Systems (DMS) monitors and collects observable information on the driver, which can be used to determine his/her driving state. It is used, among other things, for active safety, adaptive Human Machine Interface (HMI), and annoyance reduction for false positive notifications in HAD. Electrodermal Activity Electrodermal activity (EDA) is the autonomous changes in electrical properties of the skin, of which, skin conductance is the most widely used property. To measure skin conductance, an electrical potential is applied between two points on the skin, and the resulting current flow between them is measured. This includes both background tonic (Skin Conductance Level or SCL) and rapid phasic components (Skin Conductance Responses or SCRs) that result from sympathetic neuronal activity. It is useful in measuring sympathetic arousal that are tractable to emotional and cognitive states. It is associated with autonomic emotional and cognitive processing. Autonomous nervous system (ANS) generally controls the body’s unconscious actions. Sympathetic nervous system (SNS) prepares body for intense physical activity and is responsible for fight or flight responses whereas parasympathetic nervous system (PSNS) is generally associated with homeostasis and when the body is at rest, while being responsible for rest and digest functions. Some emotional responses may occur without conscious awareness or cognitive intend. EDA can be used to examine such responses (i.e., threat, anticipation, salience, novelty). Recent research has shown that EDA is also a useful indicator of attentional processing per-se, where salient stimuli and resource demanding tasks evoke increased EDA responses. There are two main components to EDA. The slower acting components the overall level, slow climbing, slow declinations over time) are known as general tonic EDA. Skin Conductance Level (SCL) is the most common measure for this and changes in the SCL are thought to reflect general changes in autonomic arousal. The faster changing elements of the signal correspond to the Phasic component, also known as Skin Conductance Response (SCR). SCRs are generally associated with startle reflex or startle response. Recent evidence suggests that both components are important and may rely on different neural mechanisms. Empatica E4 wrist band is the common device used in ITS Leeds for psychophysiological data collection, giving EDA.csv files with Unix timestamp and sampling frequency of 4 Hz. Post processing of the same is done using MATLAB R2016a and Ledalab v3.4.9. For the first study, no pre-filtering was implemented. Although it can be done to smoothen the raw signal, using EDA explorer or a low bypass filter like Butterworth filter. In EDA signal, there is generally a latency of 1-3 seconds (i.e. a delay of around 1-3 seconds from when the event occurs to when you see the change in SC levels). Continuous decomposition analysis (CDA) is generally used instead of Discrete Decomposition analysis. This method extracts the phasic (driver) information underlying EDA and aims at retrieving the signal characteristics of the underlying sudomotor nerve activity (SNA). SC data is deconvolved by the general response shape which results in a large increase of temporal precision. Then data is decomposed into continuous phasic and tonic components. It is the method generally recommended for the analysis of skin conductance data. It features the computation of several standard measures of phasic EDA. Moreover, straightforward measures such as the average (or integrated) phasic driver activity are provided. To find Event Related SCR (ER-SCR) and separate it from Non-Specific SCR (NS-SCR), the event files are loaded in and the Ev ent related SCR activity is exported. The most common minimum threshold amplitude is 0.01  µS. Peaks with amplitude below this value is not considered significant. Another key factor is to standardize the values so that it can be compared across participants. For SCL the standardization is done using the formula: ((SCL ã€â€" SCLã€â€"_min) )/((ã€â€"SCLã€â€"_max –ã€â€" SCLã€â€"_min)) equation 2.2 Where ã€â€" SCLã€â€"_min is the baseline SCL which is to be measured while keeping the participant at rest doing nothing for at least 10-15 mins and ã€â€"SCLã€â€"_max is the maximum value computed when the participant is aroused using loud noise/music for a short period of time. This is done to get the SCL range of the given participant. Since this was not done for the SM study, it can’t be implemented. This can be circumnavigated by finding the minimum non-zero SCL score and the max SCL score during the study for each participant and use this as a baseline. Some studies recommend transforming SCRs into Z-scores. This requires the mean and standard-deviation to be used instead of a hypothetical maximum (from the other methods above). This navigates around the problems associated with determining the maximum SCR response from range-corrected methods / maximal correction methods. Here each raw SCR, a mean SCR value and standard deviation of SCRs, are used to compute the Z-score which is normally distributed, has an average of 0 and a standard deviation of 1. From here one can transform these Z-scores into T-scores, which have a mean of 50 and standard deviation of 10 (thus removing minus scores). The advantage to this approach here is that the resultant z-scores are based on unambiguous mathematical factors that represent the participants typical response level and not on unwarranted assumptions about maximum SCRs. Researchers further suggested that another useful transformation might be to divide each raw SCR, by the participants mean SCR thus providing a kind of standardized ratio. Final output is to obtain the ER-SCR activity window’s average SCR in T-score format, so that it can be compared across all the participants. From this, it might be possible to deduce suggestions/reasons for certain behavior during failure. Shimomura, et al. (2008) showed in his study that frequency domain analysis enabled detection of small differences in mental workload that could not be detected by traditional amplitude domain analysis. Here the signal is transformed from amplitude domain to frequency domain using techniques such as Fast Fourier Transforms (FFT). This technique enables real-time automatic analysis. Motion artifacts can cause the EDA signal to be quite noisy. If 90% of EDA value is zero or close to zero within a 5s window (a lower bound threshold of 0.001 µS can be used, it is probably caused by the sensors losing contact with the skin during that period and they can be removed. Generally, EDA levels are found to be not changing by more than 20% while increasing and 10% while decreasing, within a 1 second time window. A moving one second median filter can be used for initial interpolation to even out the signal. The resultant acceleration from accelerometer sensor can be used to find points/periods of high movements, and the EDA signal during that same period can be checked for motion artifacts, which can be removed if necessary. A bi-cubic interpolation of the signal can be done after the filtering to account for missing data points from the removal of motion artifacts. To summarize, skin conductance generally increases with arousal, stress, salience, mental workload, anticipation and overall increase in body temperature or physical activity. But measurements from palm of the hand or feet are generally highly sensitive emotional responses and can be distinguished from skin conductance spikes due to body temperature or physical activity. Heart rate variability Heart rate (HR) is the number of times the heart beats in a minute or â€Å"bpm†, and resting heart rate is the heart rate measured while being relaxed, but awake. Amongst the general population a resting heart rate of 60-80bpm is considered pretty good. But heartbeat intervals are irregular and there is variation in time between each heartbeat. Heart rate variability (HRV) is simply the measurement of variation between heartbeats. In general, a healthy functioning body will display a greater variability between beats than a poorly functioning one. Heart period is the time interval between two successive heart beats. The Sinoatrial node (SAN) can be seen on the top left side of the figure and the Atrioventricular node (AVN) to the right of SAN. The depolarization of SAN and AVN provides the electrical driving force that triggers the contraction of the heart. SAN’s spontaneous depolarization speed is typically faster than that of AVN, which is why it’s called natural pacemaker. Electrical impulses generated by SAN stimulates each beat of the heart, thereby dictating its rhythm. Sympathetic (SNS) and Parasympathetic (PSNS) branches of the autonomic nervous system are what mainly influence SAN. Hormone and immunity can have a role as well. According to Berntson, et al. (1997) â€Å"sympathetic activity tends to increase HR and decrease HRV, whereas parasympathetic activities tends to decrease HR and increase HRV†. HRV is closely related to emotional arousal. In HRV spectrum, there are both high-frequency (HF) and low-frequency (LF) signals. HF activity generally decreases under pressure, stress, strain, focused attention etc. High stress can cause reduction in LF values as well. Individuals who worry more have shown reduction in HRV. In PTSD patients, HRV and its HF component is reduced whilst the low-frequency (LF) component is elevated. Decrease in PSNS activity or increase in SNS activity results in reduced HRV. HF activity (0.15 to 0.40 Hz), especially, has been linked to PSNS activity. LF activity (0.04 to 0.15 Hz), which is generally associated with a mixture of both SNS and PSNS. So, it’s safe to summarize that during rest periods, HF HRV tends to be higher than when the driver is engaged, stressed, focused or strained/tired. To analyze HRV, either time domain or frequency domain analysis can be implemented. Time domain methods include â€Å"measures of the variance among heart period, the variance of the differences among heart periods, and geometric methods based on the shape characteristics of heart period distributions†. The most common method used to compute heart rate variability amongst time domain methods is the square root of the mean squared successive heart period differences or the RMSSD (Root Mean Square Successive Difference) statistic. It is based on the differences between adjacent heart periods and is nominally independent of basal heart period, although heart period level and heart period variability are themselves physiologically correlated. Because of the differences between adjacent heart periods sample HRV over relatively short periods of time (the duration of a heart period), the RMSSD resolves the total variance by filtering out LF signals. Consequently, the RMSSD has been a pplied as a measure of HF based HRV. The properties of RMSSD, including its cut-off frequency and its frequency-dependent transfer function vary as a function of basal heart period. A more systematic parsing of heart period variance into specific frequency components can be achieved by frequency domain methods. There are mainly two ways to measure HRV and HR. They are Electrocardiogram (ECG) recordings and Photoplethysmogram (PPG) recordings. ECG recordings are collected by placing electrodes on the chest (near the heart), which measure electrical impulses for each cardiac cycle. QRS complex is the defining feature of ECG signal. QRS complex is the three graphical deflections seen on a typical ECG, which is Q wave (downward deflection right after P wave, which is IV.), R wave (upward deflection after Q wave) and S wave (downward deflection after R wave) which is represented by I., II. The heart’s electrical activation is measured directly by ECG recordings. It also generally shows a strong QRS complex presence in the resulting signal. Motion artifacts caused by sensor displacement due to participant movement is a common source of noise in ECG signals. These tend to fall in the same frequency range as the QRS-complexes, which can make it difficult to filter them without deforming the QRS complex. Photoplethysmogram (PPG) recordings are a less invasive method to study cardiac cycle. They generally measure the discoloration of the skin as blood perfuses through the arteries and capillaries with each heartbeat, using optical sensors. PPG is typically measured at the fingertip or at the wrist. The PPG Heart Rate Analysis generally consists of a systolic peak, a dicrotic notch, and a secondary peak called a diastolic peak (2.5b-III). In recordings with very low amplitude the diastolic peak may be absent. The main advantages of PPG over ECG are low cost, ease of setting up and non-invasive methods. Ways of obtaining the PPG signal contactless through cameras have been proposed, further reducing intrusiveness. There is generally more amplitude variation over short time-intervals, more variation in waveform morphology, as well as more noise from various sources as opposed to ECG measurements. This makes analysis of PPG more difficult. The heart signal is often split into heart rate (HR) and heart rate variability (HRV) measures. The distance between the detected heart beats (the RR-intervals, named because in the ECG, the largest amplitude peak is called the R-wave) are used to calculate them. The heart beats are represented by the peaks in both signals. Even though the measurement technique vary quite considerably between ECG and PPG, a high correlation (median 0.97) between RR-intervals extracted from ECG and PPG signals has been reported. This makes the PPG a valid alternative for human factors studies that require non-intrusive heart rate measurements, and hence will be the focus of this research. Researchers talked on how to remove motion artifacts and filter it out of EDA signal. This is explained in the last paragraph of the previous section. The same methodology can be applied to remove motion artifacts from the HR/HRV signal as well.

Effects of Medical Marijuana and Marijuana on the Brain System Research Paper

Effects of Medical Marijuana and Marijuana on the Brain System - Research Paper Example These compounds are called cannabinoids. The THC content varies according to the source of cannabis and its preparation (Ashton). Nonmedicinal effect of marijuana is the intoxication it can produce. Marijuana is rolled as cigarettes and smoked. The odor of the smoke is distinct, pungent, and sweet-and-sour. Marijuana is consumed along with food and its decoction is served as tea. All variants of marijuana produce initial excitement followed by depression (NIH). Marijuana is used in ayurveda for its medicinal properties. Its derivatives act as analgesic, anti-inflammatory, hallucinogenic, and sedative. Marijuana is recommended in cancer chemotherapy as an antiemetic and for treating glaucoma. Marijuana plant in ayurveda is used for its hallucinogenic, hypnotic, sedative, analgesic, and anti-inflammatory properties. (Rajasekar). Medical marijuana or medical cannabis is available as leaves and flowering tops. Medical marijuana is a schedule I drug. Derivatives of cannabis or marijuana are in use for their medicinal actions in United States and Canada for a long time. Such derivatives are dronabinol and nabilone that are schedule III and schedule II drugs respectively. Another derivative ‘nabiximol’ has not been approved by the USFDA (Borgelt, Franson and Nussbaum). The nature of formulation and patient’s character influence the pharmacological actions of cannabinoid compounds. The cannabinoid receptors CB1 and CB2 respond differently. The cannabinoid delta-9-tetrahydrocannabinol exerts primary psychoactive actions. Cannabinoid derivatives dronabinol and nabilone are used for treating nausea and vomiting during cancer chemotherapy. It is also given to patients suffering from anorexia due to acquired immune deficiency syndrome. Cannabis compounds are recommended for treating pain and muscle spasms (Borgelt, Franson and Nussbaum). More than 400 compounds are present in herbal cannabis. The plant genus cannabis contains more than 60