Teens with hiv taking more risks Essay Example For Students

Teens with hiv taking more risks Essay Teenagers infected with HIV are more likely to engage in risky sex and drug use since the introduction of powerful medicines that effectively keep AIDS at bay, a new study finds. The trend, which began surfacing after highly active antiretroviral therapies (HAART) were introduced in 1996, points to the need for targeted interventions to reduce risky behavior and improve quality of life for those in this group, the researchers noted. Roughly a quarter of the 40,000 new HIV infections in the United States each year occur in people under the age of 21, according to the federal Centers for Disease Control and Prevention. We will write a custom essay on Teens with hiv taking more risks specifically for you for only $16.38 $13.9/page Order now Young people, post-HAART, are engaging in more unprotected sex and engaging in more substance abuse, and are more emotionally distressed and have a lower quality of life, said lead researcher Marguerita Lightfoot, an assistant research psychologist at the University of California, Los Angeles Center for Community Health. This finding was surprising, Lightfoot added. ;I had a hypothesis that the young people who are taking HAART would be healthier, because they had more hope, they were living longer. And I was surprised that that wasnt the case. In the study, Lightfoot and her colleagues compared behaviors among 349 teens with HIV from Los Angeles, San Francisco, New York City and Miami from 1994 to 1996, with 175 teens with HIV in the same cities from 1999 to 2000. The two groups did not include the same people, but they were a similar mix of sex, age, race and ethnicity, as well as socioeconomic factors, according to the report in the March issue of the American Journal of Health Behavior. The researchers found the post-HAART group was almost two times more likely to have had unprotected sex. The post-HAART teens had almost twice the number of sex partners, compared with pre-HAART teens. And post-HAART teens were more likely to have a sexual partner who used injected drugs. In addition, the post-HAART group was diagnosed with HIV at a younger age and was in worse health than the pre-HAART group, Lightfoots team found. Lightfoot said there are a number of reasons for these findings. She noted the powerful drug regimen isnt perfect. There are increased expectations for HAART, Lightfoot said. But not everyone is successful on HAART. Lightfoot also noted that teens infected with HIV are more apt to be involved with the juvenile justice system and spend time in jail. Maybe it says something about the kind of young people who are more likely to be infected with HIV. These are the people who are most at risk, she said. In addition, because being on HAART makes people feel safer, they are more likely to engage in unprotected sex. People also feel that HAART makes HIV a disease that they can live with, Lightfoot said. This attitude is also found among HIV-positive adults, she noted. The ones who are getting infected are the ones who are not getting the prevention messages, Lightfoot said. We are seeing that as a trend among people of color, who are the fastest-growing population getting HIV. We need to be targeting these young people for interventions, not only to prevent them from transmitting the virus, but we need to be helping them with their emotional distress, Lightfoot said. We have a real opportunity to prevent the further spread of HIV if we focus on the young people who are actually living with it. Another expert found the study conclusions disturbing. It is distressing that things had gotten worse for the more recent group of teens living with HIV, said Freya Sonenstein, a professor and director of the Center for Adolescent Health at Johns Hopkins Bloomberg School of Public Health. .ud449adb3cb6b3485cc7059563bed3c0f , .ud449adb3cb6b3485cc7059563bed3c0f .postImageUrl , .ud449adb3cb6b3485cc7059563bed3c0f .centered-text-area { min-height: 80px; position: relative; } .ud449adb3cb6b3485cc7059563bed3c0f , .ud449adb3cb6b3485cc7059563bed3c0f:hover , .ud449adb3cb6b3485cc7059563bed3c0f:visited , .ud449adb3cb6b3485cc7059563bed3c0f:active { border:0!important; } .ud449adb3cb6b3485cc7059563bed3c0f .clearfix:after { content: ""; display: table; clear: both; } .ud449adb3cb6b3485cc7059563bed3c0f { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .ud449adb3cb6b3485cc7059563bed3c0f:active , .ud449adb3cb6b3485cc7059563bed3c0f:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .ud449adb3cb6b3485cc7059563bed3c0f .centered-text-area { width: 100%; position: relative ; } .ud449adb3cb6b3485cc7059563bed3c0f .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .ud449adb3cb6b3485cc7059563bed3c0f .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .ud449adb3cb6b3485cc7059563bed3c0f .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .ud449adb3cb6b3485cc7059563bed3c0f:hover .ctaButton { background-color: #34495E!important; } .ud449adb3cb6b3485cc7059563bed3c0f .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .ud449adb3cb6b3485cc7059563bed3c0f .ud449adb3cb6b3485cc7059563bed3c0f-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .ud449adb3cb6b3485cc7059563bed3c0f:after { content: ""; display: block; clear: both; } READ: Income inequality EssaySonenstein focuses on the type of teens who are most likely to become infected with HIV to explain the findings. An explanation for the study findings is that the teens living with HIV have become selectively more disadvantaged, she said. HIV transmission is now more likely among disadvantaged teens than it was in the earlier period. Still, I think that we should expect the care and support systems for this group to improve, and the call for improved programming is justified, Sonenstein added. In some good news, a report in the Feb. 28 issue of the Archives of Internal .

The Taiwan political status, the difficulty to be accepted i essays

The Taiwan political status, the difficulty to be accepted i essays The birth of a nation is always complicated. And when you belonged to one of the most powerful nation in the world, wanting to be on its own can ¡t be an easy way. Therefore, Taiwan is a model of self construction, but the emergence and the acceptation in the world order is not as easy as people thinks. A lot of interests are at stake, and the world equilibrium can ¡t be shacked easily. Historic reminder on the USA-PRC-ROC troubles In 1949, the Communist in China tried to take an overall control of the country. On October 1949, Mao Zedong proclaimed the People ¡s Republic of China. That obliged the Nationalist to escape from China and they decided to settle down on the Formosa Island 100 miles away from China. So they took the control of this island plus several offshore islands. It was a very strategic place to be because they could block some harbors in China. Thus, for the authorities in China a civil war to regain the control was inescapable. And at the beginning, the USA thought that the problem would be solved quickly. But one thing changed their mind, the communist wave trough the world (Russia, Iran, China, North Korea, and so...). They did not want another country becoming communist in this part of the world. At this period of Cold War, each victory was important. This change of policy has been influenced by John Dulles and his  ¡Domino Theory ¡. It means a chain reaction in the neighborhood of one state if this one becomes a communist state. Americans feared that if they lost Taiwan, then Japan and the Philippines would have followed the same way. So, the USA was in a hard situation, defending small islands without any resources or economic future, just in front of the Chinese coast. In December 1949 Republic Of China is created and Taipei is the capital. Hopefully for the USA, the Chinese were more concerned to keep control on their all territory and did not want to take a risk of war for small islands. During th...

Quotes From A Tale of Two Cities by Charles Dickens

Quotes From 'A Tale of Two Cities' by Charles Dickens A Tale of Two Cities is a dense classic, often studied in classrooms. Charles Dickens published the work late in his career as a popular novelist in Victorian England. The backdrop of A Tale of Two Cities is the French Revolution; and a whole myriad of colorful characters are in attendance (as is usual for the works of Charles Dickens). Here are a few quotes from the literary master. Quotes from Book 1 It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other wayin short, the period was so far like the present period, that some of its noisiest authorities insisted on its being received, for good or for evil, in the superlative degree of comparison only.- Charles Dickens, A Tale of Two Cities, Book 1, Chapter 1Jerry, say that my answer was, RECALLED TO LIFE.- Charles Dickens, A Tale of Two Cities, Book 1, Chapter 2Eighteen years! Gracious Creator of day! To be buried alive for eighteen years!- Charles Dickens, A Tale of Two Cities, Book 1, Chapter 3She had laid her head upon my shoulder, that night when I was summoned outshe had a fea r of my going, though I had noneand when I was brought to the North Tower they found these upon my sleeve. You will leave me them? They can never help me to escape in the body, though they may in the spirit. Those words I said. I remember them very well. - Charles Dickens, A Tale of Two Cities, Book 1, Chapter 6 If, when I tell you, dearest dear, that your agony is over, and that I have come here to take you from it, and that we go to England to be at peace and at rest, I cause you to think of your useful life laid waste, and of our native France so wicked to you, weep for it, weep for it! And if, when I shall tell you of my name, and of my father who is living, and of my mother who is dead, you learn that I have to kneel to my honoured father, and implore his pardon for never having for his sake striven all day and lain awake and wept all night, because the love of my poor mother hid his torture from me, weep for it, weep for it! Weep for her, then, and for me! Good gentlemen, thank God! I feel his sacred tears upon my face, and his sobs strike against my heart. O, see! Thank God for us, thank God! - Charles Dickens, A Tale of Two Cities, Book 1, Chapter 6All through the cold and restless interval, until, dawn, they once more whispered in the ears of Mr. Jarvis Lorrysitting opposite the bur ied man who had been dug out, and wondering what subtle powers were forever lost to him, and what were capable of restorationthe old inquiry: I hope you care to be recalled to life?- Charles Dickens, A Tale of Two Cities, Book 1, Chapter 6 Quotes from Book 2 But indeed, at that time, putting to death was a recipe much in vogue with all trades and professions, and not least of all with Tellsons. Death is Natures remedy for all things, and why not Legislations? Accordingly, the forger was put to Death; the utterer of a bad note was put to Death; the unlawful opener of a letter was put to Death; the purloiner of forty shillings and sixpence was put to death; the holder of a horse at Tellsons door, who made off with it, was put to Death; the coiner of a bad schilling was put to Death; the sounders of three-fourths of the notes in the whole gamut of Crime, were put to Death. Not that it did the least good in the way of preventionit might almost have been worth remarking that the fact was exactly the reversebut, it cleared off (as to this world) the trouble of each particular case, and left nothing else connected with it to be looked after.- Charles Dickens, A Tale of Two Cities, Book 2, Chapter 1I wont be gone again, in this manner. I am as r ickety as a hackney-coach, Im as sleepy as laudanum, my lines is strained to that degree that I shouldnt know, if it wasnt for the pain in em, which was me and which was somebody else, yet Im none the better for it in pocket; and its my suspicion that youve been at it from morning to night to prevent me from being better for it in the pocket, and I wont put up with it, Aggerawayter, and what do you say now! - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 1 Waste forces within him, and a desert all around, this man stood still on his way across a silent terrace, and saw for a moment, lying in the wilderness before him, a mirage of honorable ambition, self-denial, and perseverance. In the fair city of this vision, there were airy galleries from which the loves and graces looked upon him, gardens in which the fruits of life hung ripening, waters of Hope that sparkled in his sight. A moment, and it was gone. Climbing to a high chamber in a well of houses, he threw himself down in his clothes on a neglected bed, and its pillow was wet with wasted tears.- Charles Dickens, A Tale of Two Cities, Book 2, Chapter 5I have sometimes sat alone here of an evening, listening, until I have made the echoes out to be the echoes of all the footsteps that are coming by and by into our lives.- Charles Dickens, A Tale of Two Cities, Book 2, Chapter 6There is a great crowd coming one day into our lives, if that be so.- Charles Dickens, A Tale of Two Cities, Book 2, Chapter 6 What a night it has been! Almost a night, Jerry, to bring the dead out of their graves.- Charles Dickens, A Tale of Two Cities, Book 2, Chapter 6It is extraordinary to me that you people cannot take care of yourselves and your children. One or the other of you is forever in the way.- Charles Dickens, A Tale of Two Cities, Book 2, Chapter 7I know it all, I know it all. Be a brave man, my Gaspard! It is better for the poor plaything to die so, than to live. It has died in a moment without pain. Could it have lived an hour as happily? - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 7Repression is the only lasting philosophy. The dark deference of fear and slavery, my friend, will keep the dogs obedient to the whip, as long as this roof shuts out the sky, - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 9Good-night! I look to the pleasure of seeing you again in the morning. Good repose! Light Monsieur my nephew to his chamber there! And burn Monsieur my nephew in his bed , if you will. - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 9 There is no harm at all done. I have not proposed to the young lady, and, between ourselves, I am by no means certain, on reflection, that I ever should have committed myself to that extent. Mr. Lorry, you cannot control the mincing vanities and giddiness of empty-headed girls; you must not expect to do it, or you will always be disappointed. Now, pray say no more about it. I tell you, I regret it on account of others, but I am satisfied on my own account. And I am really very much obliged to you for allowing me to sound you, and for giving me your advice; you know the young lady better than I do; you were right, it never would have done. - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 12The time will come, the time will not be long in coming, when new ties will be formed about youties that will bind you yet more tenderly and strongly to the home you so adornthe dearest ties that will ever grace and gladden you. O Miss Manette, when the little picture of a happy fathers face looks up in yours, when you see your own bright beauty springing up anew at your feet, think now and then that there is a man who would give his life, to keep a life you love beside you! - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 13 But, there were other echoes, from a distance, that rumbled menacingly in the corner all through this space of time. And it was now, about little Lucies sixth birthday, that they began to have an awful sound, as of a great storm in France with a dreadful sea rising. - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 21Seven prisoners released, seven gory heads on pikes, the keys of the accursed fortress of the eight strong towers, some discovered letters and other memorials of prisoners of old time, long dead of broken heartssuch, and such-like, the loudly echoing footsteps of Saint Antoine escort through Paris streets in mid-July, one thousand seven hundred and eighty-nine. Now, Heaven defeat the fancy of Lucie Darnay, and keep these feet far out of her life! For, they are headlong, mad, and dangerous; and in the years so long after the breaking of the cask at Defarges wine-shop door, they are not easily purified when once stained red. - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 21 From such household occupations as their bare poverty yielded, from their children, from their aged and their sick crouching on the bare ground famished and naked, they ran out with streaming hair, urging one another, and themselves, to madness with the wildest cries and actions. Villain Foulon taken, my sister! Old Foulon taken, my mother! Miscreant Foulon taken, my daughter! Then, a score of others ran into the midst of these, beating their breasts, tearing their hair, and screaming, Foulon alive! Foulon who told the starving people they might eat grass! Foulon who told my old father that he might eat grass, when I had no bread to give him! Foulon who told my baby it might suck grass, when these breasts were dry with want! O mother of God, this Foulon! O Heaven, our suffering! Hear me, my dead baby and my withered father: I swear on my knees, on these stones, to avenge you on Foulon! - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 22For scores of years gone by, Monseigneur had squeezed and wrung it, and had seldom graced it with his presence except for the pleasures of the chasenow, found in hunting the people; now, found in hunting the beasts, for whose preservation Monseigneur made edifying spaces of barbarous and barren wilderness. No. The change consisted in the appearance of strange faces of low caste, rather than in the disappearance of the high-caste, chiseled, and otherwise beatified and beatifying features of Monseigneur. - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 23 For the love of Heaven, of justice, of generosity, of the honour of your noble name, I supplicate you, Monsieur heretofore the Marquis, to succour and release me. My fault is that I have been true to you. Oh, Monsieur heretofore the Marquis, I pray you be true to me! - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 24The Loadstone Rock was drawing him, and he must sail on, until he struck. He knew of no rock; he saw hardly any danger. The intention with which he had done what he had done, even although he had left it incomplete, presented it before him in an aspect that would be gratefully acknowledged in France on his presenting himself to assert it. Then, that glorious vision of doing good, which is so often the sanguine mirage of so many good minds, arose before him, and he even saw himself in the illusion with some influence to guide this raging Revolution that was running so fearfully wild. - Charles Dickens, A Tale of Two Cities, Book 2, Chapter 24 Quotes From Book 3 Five paces by four and a half, five paces by four and a half, five paces by four and a half. He made shoes, he made shoes, he made shoes. The ghosts that vanished when the wicket closed. There was one among them, the appearance of a lady dressed in black, who was leaning in the embrasure of a window, and she had a light shining upon her golden hair, and she looked like...Let us ride on again, for Gods sake, through the illuminated villages with the people all awake! - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 1The wives and mothers we have been used to see since we were as little as this child, and much less, have not been greatly considered? We have known their husbands and fathers laid in prison and kept from them, often enough? All our lives, we have seen our sister-women suffer, in themselves and in their children, poverty, nakedness, hunger, thirst, sickness, misery, oppression and neglect of all kinds? - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 3It wa s the popular theme for jests; it was the best cure for headache, it infallibly prevented the hair from turning grey, it imparted a particular delicacy to the complexion, it was the National Razor which shaved close: who kissed La Guillotine, looked through the little window and sneezed into the sack. It was the sign of the regeneration of the human race. It superseded the Cross. Models of it were worn on breasts from which the Cross was discarded, and it was bowed down to and believed in where the Cross was denied. - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 4 I call myself Samson of the firewood guillotine. See here again! Loo, loo, loo; Loo, loo, loo! And off her head comes! Now, a child. Tickle, tickle; Pickle, pickle! And off its head comes! All the family! - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 5I am the resurrection and the life, saith the Lord: he that believeth in me, though he were dead, yet shall he live: and whosoever liveth and believeth in me, shall never die. - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 9If it had pleased God to put it in the hard heart of either of the brothers, in all these frightful years, to grant me any tidings of my dearest wifeso much as to let me know by a word whether alive or deadmight have thought that He had not quite abandoned them. But, now I believe that the mark of the red cross is fatal to them, and that they have no part in His mercies. And them and their descendants, to the last of their race, I, Alexandre Manette, unhappy prisoner, do this last night of the ye ar 1767, in my unbearable agony, denounce to the times when all these things shall be answered for. I denounce them to Heaven and to earth. - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 10 Then tell the Wind and Fire where to stop, but dont tell me. - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 12If you remember the words that passed between us, long ago, you will readily comprehend this when you see it. You do remember them, I know. It is not in your nature to forget them. I am thankful that the time has come, when I can prove them. That I do so is no subject for regret or grief. If it had been otherwise, I never should have used the longer opportunity. If it had been otherwise - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 13It is a far, far better thing that I do, than I have ever done; it is a far, far better rest that I go to than I have ever known. - Charles Dickens, A Tale of Two Cities, Book 3, Chapter 15

The Monsanto Company Research Paper Example | Topics and Well Written Essays - 750 words

The Monsanto Company - Research Paper Example New technologies were also incorporated such as Roundup Ready Soybeans and Bollgard insect-protected cotton which offered farmers in-seed protection. The expansion continued through the years with acquisitions and which have seen the company become a world giant in seed technologies. The company won numerous awards in the year 2010 including being recognized among the ‘100 Best Companies to Work For’ by the Fortune Magazine. It has continued to develop farming solutions to weed and insect control and was named again in 2013 by CR Magazine among â€Å"100 Best Corporate Citizens. It also announced a $400 million to expand to allow more seed development as well as create more jobs. The company’s headquarter is in the United States but has locations across the world. These include plants for manufacturing, production facilities, and centers for research as well as learning centers all of which focus the farmers. Its locations are in all continents and its facilities have seeds for many almost all crops developed using the latest technology to ensure high yields. Their seeds range from vegetables, legumes, corn, sugar and many others. it growing popularity and expansion has seen the company acquire and own many companies such as Divergence, Inc., Chesterfield Village Rsearch Center, Aly Participacoes Ltda, CanaVialis S.A, Alellyx S.A, Semillas Cristiani Burkand, De Ruiter Seeds Group and many other companies. Monsanto Company expends over $2.6 million towards research every day. This is to ensure development and production of quality seeds to the benefit of farmer and the agricultural industry as a whole and for this reason it protects it seeds with patents. It also places patents so as to ensure farmer do not reuse seeds bought seeds and this goes towards ensuring their investment are paid for. Indeed without such protections there is no incentive for

The Acts of Remembering and Memorializing Assignment

The Acts of Remembering and Memorializing - Assignment Example The rhetoric significance of the artifact becomes the critical issue that invites fresh interpretations that affect the present and the future. According to Foss (1986), Vietnam Veterans Memorial successfully appeals to the visitors because it not only violates the conventional form and expectations but exploits visitors’ personal experience and evokes memories that are unique. Foss believes that aesthetic response and rhetoric response are different. Aesthetic response is designed towards providing visitors with pleasant sensory feelings, especially the visual aspects in terms of color, shape, design etc. But the rhetoric response tends to explore hidden meaning to the shape, color, and environment. The difference between the two is important because aesthetic and rhetoric responses together give credence to the success of the artifact. They ensure that it serves its basic purpose of remembering and memorialization of past which can be interpreted creatively to connect with the present. According to Blair and Michel (2000), the Civil Rights Memorial performs civil rights tactics because the artifact is able to engage visitors and goads them to delve deeper and connect. This is interesting because the artifact is strategically located at Montgomery, Alabama which is rich in civil rights history and on the open plaza which is near to the Church where Martin Luther King served as pastor and where the voting march rights had ended in 1965. Performance plays important role in the remembering and memorializing because the public memorials need to evoke images of the past which should instigate responses from the visitors and engage them in constructive dialogues. Blair and Michel’s ideas closely relate with that of Olson, Finnegan, and Hope because they all agree that public memorials impel rhetoric responses which make people interact not only with the artifacts but also with the historical past.

Development of Hard Water Sensor using Fluorescence

Development of Hard Water Sensor using Fluorescence Ph.D. Thesis: Dibyendu Dey Development of hard water sensor using fluorescence resonance energy transfer 7.1. Introduction â€Å"Hard water† has high mineral content in compare to â€Å"soft water†. Generally the hard water is not harmful to one’s health, but can cause serious problems in industrial settings, where water hardness should be monitored to avoid breakdowns of the costly equipments that handle water. The hardness of water is determined by the concentration of multivalent cations in water. The most common cations found in hard water include Ca2+ and Mg2+. The presence of dissolved carbonate minerals (CaCO3 and MgCO3) provide a temporary hardness in water, which can be reduced either by boiling the water or by addition of lime (calcium hydroxide) [1, 2]. On the other hand the dissolved chloride minerals (CaCl2 and MgCl2) cause the permanent hardness of water that can not be removed easily, as it becomes more soluble as the temperature increases [3]. In that sense it is very important to identify the permanent hardness of water before use. The FRET phenomenon may be very effective tool for the designing of hard water sensors. Based on the FRET between two laser dyes here we demonstrated a hard water sensor. To the best of our knowledge this could be the first attempt, where FRET process has been used for the detection of the hardness of water. FRET between two molecules is an important physical phenomenon, where transfer of energy from an excited fluorophore to a suitable acceptor fluorophore occurred [4, 5]. This technique is very important for the understanding of some biological systems and has potential applications in optoelectronic and thin film devices [6–10]. Combining FRET with optical microscopy, it is possible to determine the approach between two molecules within nanometers. The main requirements for the FRET to occur are (i) sufficient overlap between the absorption band of acceptor fluorophore and the fluorescence band of donor fluorophore and (ii) both the donor and acceptor molecule must be in cl ose proximity of the order of 1–10 nm [4, 5]. The intervening of solvent or other macromolecules has little effect on the FRET efficiency. If the distance between the donor and acceptor changes then FRET efficiency also changes. In this chapter of the present thesis we tried to investigate the effect of Mg2+ or Ca2+ or both on the FRET efficiency between two fluorophores, Acf and RhB in presence of nanoclay sheet laponite. Here we have chosen Mg2+ or Ca2+ because the presence of these two cations mainly determines the extent of hardness of the water. Our investigation showed that FRET efficiency decreases with increasing salt concentration. It has also been demonstrated that with proper calibration, FRET between Acf and RhB can be used to sense the hardness of water. 7.2. Experimental 7.2.1. Solution preparation Both the dyes Acf and RhB were used in our studies are cationic in nature. The clay mineral used in the present work was Laponite. Dye solutions were prepared in Milli-Q water. For spectroscopic measurement the solution concentration was optimized at 10−6M. In order to check the effect of hard water components (Ca2+ and Mg2+ ions) on spectral charecteristics, MgCl2 and CaCl2 were added to the dye solution. The clay dispersion was prepared using Millipore water and stirred for 24 h with a magnetic stirrer followed by 30 min ultrasonication before use. The concentration of clay was kept fixed at 2 ppm throughout the experiment. To check the effect of clay on the spectral characteristics the dye solutions (Acf and RhB) were prepared in the clay suspensions (2 ppm). In order to check the effect of salt on spectral characteristics in presence of clay, first of all the salts were added in the clay dispersion at different concentration. Then the dyes were added in the salt mixed clay dispersions. In all cases the clay concentration was 2 ppm and the dye concentration was 10−6M. 7. 3. Results and discussion 7.3.1. Sensing of Hard Water by FRET FRET between Acf and RhB has already been studied and the results are shown in details in chapter 5 of this thesis. Here in this chapter we have used this same FRET pair for the sensing of water hardness. Our main purpose is to detect CaCl2 and MgCl2 or their mixture as a permanent hard water component in aqueous solution by using the FRET process between Acf and RhB. Fluorescence spectra of aqueous solution of Acf-RhB mixture in presence of MgCl2, CaCl2 and their mixture (CaCl2+MgCl2) have been studied (figure 7.1). For all the cases, the concentration of CaCl2/MgCl2/their mixture was kept at 0.06 mg/ml, which is the initializing concentration of hard water known as moderately hard water. Fig. 7.1. Fluorescence spectra of Acf+RhB (1:1 volume ratio) in water solution (1), with MgCl2 (2), CaCl2 (3), and CaCl2+MgCl2 (4), pure Acf (5), pure RhB (6). Dye concentration was 10-6M and salt concentration was 0.06 mg/ml. It was observed that the transfer of energy from Acf to RhB decreased in presence of salt (shown in table 7.1). The FRET efficiencies are calculated by using the Fà ¶rster theory. The introduction of cationic Ca2+ and Mg2+ ions in the solution may cause an increase in the electrostatic repulsion between cationic Acf and RhB molecules which can result in a large intermolecular separation. Accordingly, the FRET efficiency decreases. Samples E% Acf+RhB 11.37 Acf+RhB+ CaCl2 1.7 Acf+RhB+ MgCl2 5.2 Acf+RhB+ MgCl2 +CaCl2 4.38 Acf+RhB+clay 78.17 Acf+RhB+ CaCl2 with clay 37.78 Acf+RhB+ MgCl2 with clay 51.59 Acf+RhB+ MgCl2 +CaCl2 with clay 48.18 Table 7.1 Values of energy transfer efficiency (E %) for Acf and RhB mixture (1:1 volume ratio) in different conditions. The salt concentration was 0.06 mg/ml (moderately hard water). Fig. 7.2. Fluorescence spectra of Acf+RhB (1:1 volume ratio) in clay suspension (1), with MgCl2 (2), CaCl2 (3), and CaCl2+MgCl2 (4) pure Acf with clay (5), pure RhB with clay (6). Dye concentration was 10-6M and clay concentration was 2 ppm and salt concentration was 0.06 mg/ml. In the present study our aim is to design a sensor which can sense the presence of Ca2+ or Mg2+ or both by observing the change in FRET efficiency. Accordingly it is very important to have large FRET efficiency between Acf and RhB as well as noticeable change in FRET efficiency between Acf and RhB due to the introduction of hard water components (Ca2+ or Mg2+), so that we can use it as a hard water sensor with minimum error level. Accordingly in order to enhance the FRET efficiency, we have incorporated nano clay laponite in Acf-RhB mixture (figure 7.2). It has been observed that the FRET efficiency increases in presence of laponite particle. The reason of increase in FRET efficiecy in presence of clay has been explained in details in chapter 5. It was also observed that the transfer of energy from Acf to RhB decreases quite remarkably due to the introduction of CaCl2/MgCl2/their mixture for the concentration of 0.06 mg/ml in presence of clay. It was observed that the transfer of ene rgy is much smaller due to the presence of CaCl2 in compare to MgCl2. (Table 7.1 summarize the calculated efficiencies). Fig. 7.3. Schematic representation of FRET between Acf and RhB in presence of clay and salt. The decrease in FRET between Acf and RhB in presence of hard water components, must involve the reaction of the cations (Ca2+ and Mg2+) present in hard water with the clay minerals through cation exchange reaction. In general, this bonding energy is of the order: Ca > Mg > K > H > Na. Thus the probability of adsorption of Ca2+ in clay suspension is more than Mg2+. The tendency of Ca2+ ion to interact with the negatively charged clay layers is more compared to Mg2+ ion of same concentration of both clay suspension and salt solution. Accordingly, most of the negative charges in the clay surfaces are neutralized by Ca2+ ion compared to Mg2+ ion and there exists very few unoccupied negative charges on the clay surface for the cationic dye molecules to be adsorbed. As a result the separation between the cationic dye molecules increases more in CaCl2 solution rather than MgCl2 leading to a less FRET in presence of CaCl2 compare to MgCl2 (shown schemetically in figure 7.3). 7.3.2. Variation of salt concentration In order to check the extent of hardness on the FRET efficiency, we have measured the fluorescence spectra of Acf+RhB mixture with different salt (MgCl2, CaCl2, and MgCl2+CaCl2 mixture) concentration in presence of clay laponite and the FRET efficiency have been calculated. It has been observed that the FRET efficiency decreases with increasing salt concentration of either MgCl2 or CaCl2, or their mixture (figure 7.4). This result suggests that it is possible to sense the hardness of water by observing the change in FRET efficiency with salt concentration. Fig. 7.4. The fluorescence spectra of Acf–RhB mixture in presence of clay with varying amount of salt (MgCl2+CaCl2 mixture) concentration viz. 0.05 mg/ml (1), 0.06 mg/ml (2) and 0.12 mg/ml (3). Inset shows the variation of FRET efficiency as a function of salt concentration of either MgCl2 or CaCl2, or CaCl2+ MgCl2 mixture from 0.03 mg/ml to 0.20 mg/ml. Salt concentration (mg/ml) FRET efficiency (E%) in presence of MgCl2 CaCl2 MgCl2+CaCl2 mixture 0.03 78.52 64.27 73.73 0.05 71.55 55.32 68.34 0.06 51.59 37.78 48.18 0.08 32.47 18.75 21.57 0.12 19.67 10.54 13.48 0.20 11.34 5.67 07.38 Table 7.2 Values of energy transfer efficiency (E %) for Acf-RhB mixture (1:1 volume ratio) at different salt (MgCl2, CaCl2, MgCl2+CaCl2 mixture) concentration in presence of clay. MgCl2 and CaCl2 mixture were prepared by adding 1:1 volume ratio of individual salts of same concentration. 7.3.3. Design of sensor In the process of hard water sensing first of all clay (laponite) dispersion will be prepared using the sample water followed by addition of dyes (Acf and RhB). By observing the FRET efficiency between Acf and RhB it would be possible to sense the hardness of the test water. Fig. 7.5. FRET efficiency of Acf-RhB mixture for the different concentration of CaCl2 + MgCl2 in presence of clay (values of FRET efficiencies were calculated from spectra of Fig. 7.4). From figure 7.5 it has been observed that the FRET efficiency for 0.06 mg/ml and 0.12 mg/ml concentration are 48.2% and 13.5% respectively. If the FRET efficiency is observed to be higher than 48.2%, then the water will be recognized as soft water whereas, if the efficiency lies in between 13.5% and 48.2% then the water will be recognized as moderately hard. On the other hand if the observed FRET efficiency is less than 13.5% then the water will be recognized as very hard. Therefore with proper calibration it is possible to design a hard water sensor which can sense hard water very easily. 7.4. Conclusion In order to demonstrate hard water sensor based on FRET, we have investigated the FRET between Acf and RhB in presence of salts CaCl2 or MgCl2 or both. It was observed that the presence of hard water components Ca2+ or Mg2+ or both affected the FRET efficiency to a large extent. In presence of CaCl2 or MgCl2 the FRET efficiency is decreased to 37.78% and 51.59%, respectively. With suitable calibration of these results it is possible to design a hard water sensor that can sense the water hardness within the range 0.03–0.2 mg/ml. Here the incorporation of clay platelate laponite enhances the sensing efficiency.

Obesity Is a Disease

Obesity Is A Disease Obesity is a disease that affects one in three members of the American population. The trend of obese Americans has continually increased since 1960, and is not showing signs of slowing down. More than half of the adults in America are considered overweight or obese, and about thirty-four percent of the total population in the U. S is either overweight or obese. One is considered â€Å"overweight† if the body mass index, or BMI, is twenty-five to twenty-nine kilograms. â€Å"Obese† is any number thirty or greater (Hateweight. com). Obesity is the cause of at least 300,000 deaths in the U. S every year, second only to smoking (American Obesity Association). There are many causes of obesity, some of which are environmentally related and others are geneticly related. Genetics from an obese relative can be passed from generation to another; this form of obesity is hard to control without proper treatment (Hateweight. com). The American culture has been the biggest cause of obesity. All of our surroundings and social environments have greatly influenced obesity. Most social events revolve around food or drinks, which are usually unhealthy for the body. Food itself has become a reward; young children are often rewarded for good behavior with a â€Å"treat† (American Obesity Association). This treat is often a child’s favorite candy or sweet. Adults also use food as a reward. Successful business transactions between companies are often celebrated with food and drinks. Employees often stop after work to have drinks and possibly dinner to celebrate. Alcoholic drinks are very high in fat and have no nutritional value. Also, most restaurant food is high in fat and calories. Another factor which is the cause of this disease is lifestyle. People are no as physically active as they should be. They have become more dependent on someone else to do their work for them. An example if this would be fast food restaurants. Why make dinner when you can go up the street and have someone else cook it for you? Most meals from fast food restaurants have almost fifty percent, if not more calories than a person needs for one day. Another cause of obesity would be a person’s mental state. People cope with life changing experiences differently, such as a death of a family member or the loss of a job. These types of events cause some people to over-eat and, over time, become overweight. Obesity has many effects on a person both psychologically and physically. Psychologically, obesity may cause a person to become depressed and even become suicidal. Not only that, but it can also cause low self esteem (Hateweight. com). Physically, obesity has a greater effect, because it is known to cause many other health related issues. Arthritis may occur in the hands, hips, back, and knees from the extra weight a person would be carrying around. Seventy-five percent of people with hypertension are obese. The risk of developing hypertension is five times greater in an obese person than compared to a non-obese individual. Obesity is also the leading cause of cardiovascular disease, carpal tunnel syndrome, chronic venous insufficiency, daytime fatigue, deep vein thrombosis, diabetes type 2, infections following wounds, infertility, liver disease, lower back pains, obstetric and gynecologic complications, sleep apnea, stroke, and surgical complications(American Obesity Association). Not only does obesity cause all of those diseases, but it also increases an individual’s chance of getting many different types of cancer. Breast cancer, esophagus and gastric cardial cancers, colorectal cancer, endometrial cancer, and renal cell cancer all have been linked to obesity in one way or another (American Obesity Association). Treatment for obesity comes in many forms. One form is called dietary therapy, were a doctor will devise, a diet which an individual should follow to lose weight. The diet usually consists of more healthy foods with low calories and smaller portions. Along with a diet plan the doctor recommends physical activity, which is another treatment. Physical activity could be anything from working out at a gym or playing sports to just moving around the house more. Behavior therapy is a combination of both dietary and physical therapy in which the doctor comes up with new diet and physical activity habits to promote weight loss (Hateweight. com). The treatment with the biggest risk is surgery. An individual may have their stomach stapled so they will eat smaller portions of food and, which causes the body to burn the fat cells faster because there are fewer calories coming in. Obesity is a serious matter because of all the risks that follow it. The only way to stop obesity is to become more informed and more knowledgeable of the foods we consume, and to become more physically active. Obesity is the second leading cause of unnecessary deaths in the U. S. Despite its death toll is has not received the attention it needs from the government. Bibliography www. hateweight. com www. obesity. org www. nlm. nih. gov/medlineplus/obesity. html http://www. obesity-online. com/ http://www. cdc. gov/nccdphp/dnpa/obesity/