Free Essay

Nothing

In: Business and Management

Submitted By donk1
Words 2627
Pages 11
Plant Defense Mechanisms
Constitutive plant defense responses

Are also called pre-existing or passive defense mechanism mediated by Cutin, waxes, Suberin hydrophobic materials that coat plant surfaces exposed to air prevents water loss and blocks pathogen entry and are high levels of toxic or feeding deterrent compounds. Always present and often species-specific and may exist as stored or conjugated compounds. Most secondary metabolites as defense are constitutive but some are also induced.

Pre-existing (passive or constitutive) structural defense mechanisms

Constitutive structural defense is achieved by constituents of cutin, waxes, and Suberin

• Cutin

o A macromolecule, a polymer consisting of many long-chain fatty acids (16:0 and 18:1 fatty acids with OH)

o Component of cuticle, increase resistance; however, its thickness is not always correlated with resistance

• Waxes

o Not macromolecules, but complex mixtures of long-chain acyl lipids.

o Forms a water-repellent surface and thereby prevent the formation of a film of water on which pathogens might be deposited and germinate (fungi) or multiply (bacteria).

• Suberin

o Polymer whose structure is poorly understood.

o A principle component of outer cell walls of all underground organs and is associated with the cork cells of the periderm, the tissue that forms the outer bark of stems and roots during secondary growth of woody plants.

o Suberin also forms at sites of leaf abscission and in areas damaged by disease or wounding.

Pre-existing (passive or constitutive) structural defense mechanisms is the first line of defence in plants is present in its surface. Several characters of the plants surface function as barriers to penetration which pathogen must breach to enter the host. The pathogens enter the plant host by penetrating the epidermis along with cuticle and cuticular wax and number of natural openings existing before the onset of the pathogenesis can obstruct penetration. If the pathogen succeeds in penetration; it encounters pre-existing internal structural barriers. The external and internal structural barriers existing before pathogen attack are also called pre-existing defence structures or passive/static or anit-infection structures.

Wax and cuticle

The cuticle covers the epidermal cells of plants and consists of pectin layer, a cutinized layer and a wax layer. Cutin is composed of fatty acids. Waxes are mixture of long chain aliphatic compounds which prevent the retention of water on plant surface essential for spore germination. A negative charge usually develops on leaf surfaces due to fatty acids. This condition repels air-bone spore / propogules. Only few pathogens are known to dissolve cutin enzymatically. Examples: Monilinia fructicola penetrates cuticle of cherry leaves but not of Gingko biloba leaves; the latter contains abundant cutin than the former. F. solani f sp. Pisi produces the enzyme cutinase production by specific antibodies and inhibitors.

Epidermal layer

Epidermis is the first layer of living host cells that comes in contact with attacking microbes. The toughness of epidermis is due to the polymers of cellulose, hemicelluloses, lignin mineral substances, polymerized organic compounds, suberin etc. Potato tubers resistant to Pythium debaryanum contain higher fibre. Silicon accumulation in epidemal walls provides resistance against fungal attack. Suberization of epidermis confers protection against plant Xanthomonas axonopodis pv. Citri because of broad cuticular lips covering the stomata. A functional defence mechanism has been observed in some varieties (cv-Hope) in which stomata open late in the day when moisture on leaf surface has dried and the infection tunes have become non-functional.

Hydathodes

Hydathodes are natural openings on the edges of leaves and serve to excrete excess water from the interior. They are easy entry pints of bacterial pathogens such as black rot of cabbage. Similar to hydathodes are the nectarthodes in inflorescence of many plants. They secrete sugary nectar and this serves as barrier to those organisms that cannot tolerate this condition and thus, can enter through nectarines. Leaf hairs on leaves and on nectarines also resist entry of pathogens. High hairlines of leaves and pods in chickpea is resistant character against Ascpchyta rabei. Groundnut varieties showing resistance to Cercospora leaf spots have thick epidemis-cum cuticle and compact paslisade layer, few and smaller stomata and high frequency or trochomes on the abaxial surface of leaf.

Lenticels

Lenticels are opening in outer walls involved in gaseous exchange. They are weak points in defence unless the cork cells within them are suberized. After suberizatoin and periderm formation, lenticels are more resistant to invasion by pathogens.

Pre-existing biochemical defence

Plants liberate different chemicals, which interfere with activities of the pathogen and pathogenesis, thereby preventing or reduce infection. These chemicals and the biochemical conditions that develop may act either directly through toxic or lytic effect on the invader or indirectly through stimulating antagonistic plant surface microflora. The compounds pre-existing in plants as constitutive antibiotics and those, which are formed in response to wounds as wounds antibiotics.

Release of anti-microbial compounds

Plants while growing and developing release gases as well as organic substances, from leaves and roots (leaf and root exudates), containing sugars, amino acid, organic acids, enzymes, glycoside etc. These materials have profound effect on the nature of surrounding environment, particularly the phyllosphere, rhiizosphere microflora and fauna.

Although these substances are ideal nutrients for microbes and help in germination and growth of several saprophytes and parasites number of inhibitory substances is also present in these exudates. Theses inhibitory substances directly affect the microorganism, or encourage certain groups to dominate the environment and function as antagonists of the pathogen.

Inhibitors present in the plant cells

In many host-parasite interactions, pre-existing toxic substances in the cells form the basis of resistance. In resistant variety these substances life in abundance while in susceptible variety they may be less or completely absent. Several phenollic compounds, tannins and some fatty acid like compounds such as dienes pre-exisitg in high concentrations in cells have been implicated for the resistance or young tissues to parasitic fungi such as Botrytis. Many such compounds are potent inhibitors of many hydrolytic enzymes. Several other types of preformed compounds such as saponins (glycosylaled steroidal or triterpenoid compound) tomatine in tomato and avenacin in oats, have antifungal membranolytic activity.

The fungal pathogens which lack enzymes (saponinases) that breakdown the saponins are prevented from infecting the host. Several preformed plant proteins have been reported to act as inhibitors of pathogen proteinases or of hydrolytic enzymes. Similarly lactins (proteins that bind to certain sugars) cause lyses and growth inhibition of many fungi. Plants surface cells also contain variable amounts of hydrolytic enzyymes such as glucanases and chitinases, which may cause breakdown of pathogen cell wall components.

Production of essential factors

Recognition factors

The first step in infection process is the cell-to-cell communication between host and pathogens. Plants of species or varieties may not be infected by pathogen if their surface cells lack specific recognition factors. If the pathogen does not recognize the plant as one of its hosts it may not adhere to the host surface or it may not produce infection substances such as enzymes, or structures (appresoria, haustoria). These recognition molecules are of various types ofoligosaccharides and polysaccharides and glycoproteins.

Host receptors and sites for toxins

In many host parasite interactions the pathogen produces host specific toxins, which are responsible for symptoms and disease development. The molecules of toxin are supposed to attach to specific sensitive sites or receptors in the cell. Only the plants that have such sensitive sites become diseased

Essential nutrients and growth factors

The fact that many facultative saprophytes and most of the obligate parasites are host specific and sometimes are so specialized that they can grow and reproduce only on certain varieties of those species suggests that for these pathogens the essential nutrients and growth factors are available only in these hosts. Absence of these nutrients and stimulus make the other varieties and species unsuitable hosts.

Induced or active Defence mechanism

Plants have to face the wide variety of pathogens standing at a place thus pre-existing (structural and biochemical) defence mechanism in plants exists which help plants in warding-off most of microbes as non-pathogens but it does not seems to be sufficient. The induced or active defence mechanism in plants may operate at different levels

o Biochemical defence

o Defence at cellular level

o Defences at tissue level

The activation or induction of defence mechanism may be both specific and non-specific. Several structural changes are induced by a range of biotic or abiotic elicitors. These defence mechanisms prevent further colonization or spread of pathogen. Active defence in plants involves cellular defences that rely upon preformed surveillance systems are encoded by resistance genes. The receptor-proteins are located in cell membrane to detect the pathogen or factor translocated by pathogens. The ability of plant to mount an active defence response is under genomic control. Disease occurs when

• Pre-exisiting defence mechanism are not enough to check the entry of pathogen

• A pathogen avoids timely eliciting active defence system in plant tissue or habits active defence response by secreting metabolic toxins.

Induced structural defence mechanisms

Induced histological defence which operates even after the establishment of infection in plant cells, the host defence system tries to create barriers for further colonization of tissues. This may be at various levels.

• Lignification

o Lignified cell wall provide effective barrier to hyphal penetration. They also act as impermeable barrier for free movement of nutrient causing starvation of pathogen.

o Following are examples; Radish: Peronospora parasitica, Alternaria japonica; Potato: Phytophtora infestans; Wheat: Septoria nodorum; Cucumber: Cladosporium cucumerium, Colletorichum lagenarium and Carrot: Botrytis cineria

• Suberization

o In several plants the infected cells are surrounded by suberized cells. Thus, isolating them from healthy tissue.

• Corky layer formation

o Corky layer formation is a part of natural healing system of plants e.g. common scab of potato and rot of sweet potato are good examples.

• Abscission layers

o It is a gap between host cell layers and devices for dropping off older leaves and mature fruits.

o Plant may use this for defence mechanism also i.e. to drop off infected or invaded plant tissue or parts, along with pathogen and shot holes in leaves of fruit trees is a common feature

• Tyloses

o The tyloses are formed by protrusion of xylem parachymatous cell walls, through pits, into xylem vessels.

o The size and number of tyloses physically block the vessel.

o The tyloses are inductively formed much ahead of infection, thus blocking the spread of pathogen.

o It suggests biochemical elicitors and movement of tyloses inducing factor (TIF) up the stem e.g. Sweet potato: Fusarium oxysporum

• Gum deposition

o The gums and vascular gels quickly accumulate and fill the intercellular spacis or within the cell surroundings the infection thread and haustoria, which may starve or die.

Induced cellular defence

Involves cellular defence structures, i.e. changes in cell walls and have only a limited role in defence and commonly observed examples include

o Carhohydrate apposition - synthesis of secondary wall and papillae formation

o Callose deposition - hyphal sheathing just outside plasma lemma around the haustorium which delays contact of pathogen Phytophythora infestans with host cells.

o Formation of structural proteins

o Induced cytoplasmic defence that present last line of host defence and may effective against slow growing pathogens, weak parasites or some symbiotic relationship.

Induced biochemical changes

The induced biochemical changes in host plants are the last line of host defence and may condition a plant or plant tissue from susceptible to resistant to immune status as per their genetic potential. The role of biochemical factor in host defence is based on the following four attributes

• The substance is associated with protection against disease at the site where protection occurs.

• The substance can be isolated from the host showing protection against the disease.

• Introduction of isolated substance to the appropriate susceptible host confers protection.

• The nature of protection so induced resembles that of the natural agents of a resistant plant.

The induced biochemical changes in host plants include

• Production of toxic substances

o Rapid production/suitable modifications and/or/ accumulation of chemicals toxic to pathogen upto effective concentrations is an important component of overall active defence strategy of plants.

o Slow production or accumulation or low levels of similar chemicals have reported in susceptible host plants also.

• Synthesis of phenolic compounds

o The phenolic compounds, chlorogenic acid caffeic acid and ixidation products of floretin, hydroquinone hydroxyquionones and phytoalexins are main toxi chemical produced to inhibit pathogen or its activities.

o Some of these are performed toxic chemicals while others may be de novo synthesized or modified to more toxic forms.

o The enzymes involved in chemical pathways are present in host cell which are pre-existing defense mechanisms.

• Synthesis of phytoalexins

o Most common response of plants to stress, biotic (phytoalexins/insects) or abiotic (wounding), is the production and accumulation of substrates that can inhibit the growth and activities of the biotic factors or may help in healing process.

o Phytoalexins are antibiotics produced in plant pathogens interactions or as result reposnse to injury or other psychological simulation.

• Synthesis of new proteins

o Post-infectional changes in host cells involve production and modification of large number of proteins both structural and enzymatic, which have important role in defence mechanism.

o The enzymes are required for various synthetic pathways, normal or modified for production of resistance related substances. In addition, phenol-oxidizing enzymes have vital role. The influence of these changes may be confined to infection site or nearby cells.

o Increased synthesis and activity of phenyl ammonia lyase (PAL) has been reported in several bacterial and viral pathogens in resistant reaction which plays key role in syntheses of phenols, phytoalexins and lignin.

o The effectiveness of resistance depends on speed and amount of synthesized products and their movements to neighboring healthy tissues to create defensive barriers.

• Inactivation of enzymes and toxins

o The necrotrophs and hemihiotrophs employ more of these substances from causing those tissue damage as compared to speacialized obligate parasites.

o The defence strategy of resistant plants, through activity of phenols, tannins and protein as enzymes inhibitors. The phenolics are not anti-fungal but make pathogen ineffective by neutralizing their enzymes.

o In immature grape fruits catechol-tannin is known to inhibit enzymes produced by Botrytis cinerea.

o Toxins are known to be involved in pathogenesis to various editents (pathotoxins/vivotoxins). The resistance to toxins, in host is resistance to pathogens achieved by detoxification or lack of receptor sites for these toxins

• Alteration of biosynthetic pathway

o The pose inflectional metabolism of host tissue is altered stress physiology to cope with the advancing activities of pathogen and new enzymes are produced in an effort to synthesize defence related substances.

o Most of these compounds are formed through Shikmic acid pathway and modified acetate pathway.

o Respiration in diseased tissue is invariably increased; a part of glycolysis is replaced by pentose pathway, which yields four carbon compounds are formed through Shikmic acid pathway and modified acetate pathway.

o It is possible that in early stages of infection the gene regulation of host cell is influenced and some specific genes.

Active defense to pathogens

Induction of host resistance, structural or biochemical seems to be universal in plants. Active defense responses against all classes of pathogens (fungi, bacteria, viruses and nematodes) exists. Active defense response may lead to incompatible host-pathogen interaction. The biochemical defense response are achieved by use of secondary metabolites and they differ from primary metabolites in distributions. Particular secondary metabolites are often found in only one plant species or related groups, whereas primary metabolites are found throughout the plant kingdom. They defend plants against herbivores and pathogens and have three ecological functions:

• Protect from against herbivores or pathogens • Attractants for pollinators and seed-dispersing animals • Agents of plant-plant competition and plant-microbe symbiosis…...

Similar Documents

Free Essay

Nothing

...be scary at first and that it probably won’t be perfect. Don’t be too hard on yourself. Simply resolve to learn from each attempt how to do it better next time. Becoming assertive may be one of the hardest things you have ever done (it was for me), but learning it and mastering it is one of the most rewarding. Even though I’m still working on mastering it, I now find it fun to come up with an effective assertive statement. 6. Celebrate each success. Give yourself a pat on the back for each time you are assertive. Each attempt will boost your confidence. One of best things about assertiveness is that when you master it, you are often able to be assertive in such a way that you leave people speechless with their jaws dropped. There is nothing left for them to say. It feels so good to do this! Sublimation Sublimation is simply the channeling of unacceptable impulses, thoughts and emotions into more acceptable ones. For instance, when a person has sexual impulses they would like not to act upon, they may instead focus on rigorous exercise. Refocusing such unacceptable or harmful impulses into productive use helps a person channel energy that otherwise would be lost or used in a manner that might cause the person more anxiety. Sublimation can also be done with humor or fantasy. Humor, when used as a defense mechanism, is the channeling of unacceptable impulses or thoughts into a light-hearted story or joke. Humor reduces the intensity of a situation, and places a cushion......

Words: 1234 - Pages: 5

Free Essay

Nothing

...------------------------------------------------- Philosophy Western philosophy Some would consider the study of "nothing" to be foolish, a typical response of this type is voiced by Giacomo Casanova (1725–1798) in conversation with his landlord, one Dr. Gozzi, who also happens to be a priest, “ | As everything, for him, was an article of faith, nothing, to his mind, was difficult to understand: the Great Flood had covered the entire world; before, men had the misfortune of living a thousand years; God conversed with them; Noah had taken one hundred years to build the ark; while the earth, suspended in air, stood firmly at the center of the universe that God had created out of nothingness. When I said to him, and proved to him, that the existence of nothingness was absurd, he cut me short, calling me silly.[3] | ” | However, "nothingness" has been treated as a serious subject worthy of research for a very long time. In philosophy, to avoid linguistic traps over the meaning of "nothing", a phrase such as not-being is oftenemployed to unambiguously make clear what is being discussed. Parmenides One of the earliest western philosophers to consider nothing as a concept was Parmenides (5th century BC) who was a Greek philosopher of the monist school. He argued that "nothing" cannot exist by the following line of reasoning: To speak of a thing, one has to speak of a thing that exists. Since we can speak of a thing in the past, it must still exist (in some sense) now and......

Words: 2165 - Pages: 9

Free Essay

Nothing

...so that the wheel somewhat resembles the inner half of a grapefruit. The clown and unicycle together stand about a foot high. As a cherished gift from my good friend Tran, this colorful figure greets me with a smile every time I enter my room. Here is the final version of the descriptive paragraph that appears in the exercise Practice in Supporting a Topic Sentence with Specific Details5. Compare this version with the earlier one to see which descriptions have been retained, what information has been omitted, and how sentences have been reworded and rearranged. 2) The Blond Guitar by Jeremy Burden My most valuable possession is an old, slightly warped blond guitar--the first instrument I taught myself how to play. It's nothing fancy, just a Madeira folk guitar, all scuffed and scratched and finger-printed. At the top is a bramble of copper-wound strings, each one hooked through the eye of a silver tuning key. The strings are stretched down a long, slim neck, its frets tarnished, the wood worn by years of fingers pressing chords and picking notes. The body of the Madeira is shaped like an enormous yellow pear, one that was slightly damaged in shipping. The blond wood has been chipped and gouged to gray, particularly where the pick guard fell off years ago. No, it's not a beautiful instrument, but it still lets me make music, and for that I will always treasure it. In the next descriptive paragraph, the student writer focuses less on the physical......

Words: 1004 - Pages: 5

Free Essay

Nothing

...M4 – Analyse the reasons why costs need to be controlled to budget. Introduction – for this assignment I will be analysing the advantage and disadvantage about the business that brad owns, which involves transporting business people to and from the airports using luxury cars. Furthermore I will also explain what the word budget, fixed, variable and total costs means. The main topic that I will cover is the fact that if brad does nothing to his costs than what effects will it have on the business as well as him. Explain: 1) If they are not monitored then: - Managers may not notice problems because he can’t take steps to correct the problems if he doesn’t know it exists, he won’t know if he made more adverse or more favourable. If Brad doesn’t know that he have made more adverse than he will not be able to know how much adverse he have made and on which item. If the costs are not controlled by him than he will go above his budget and he will make a loss. 2) Paste in the Eco Clothing variance analysis and explain why it may be overspent in each area of adverse variance (refer to your completed hand-out) 3) What problems might this create? - Reduced profits - problem because…. - The need to replace/better train staff - problem because…. - The need to source new material suppliers/renegotiate - problem because…. - Pressure to increase prices - problem because…. Conclusion – • Consider (and then explain) how without the budgeting process (the......

Words: 391 - Pages: 2

Premium Essay

Nothing

...Nothing – A mere seven characters long word but with such significance in our lives, which cannot be ignored. It has such diverse number of uses in our lives which we cannot even imagine. Everything, from us to the whole universe, started with this one word. It is the beginning of everything. As we can say, the step zero of all the processes is always ‘Nothing’. If something is already there then it cannot re-originate. Nothing existed before the Big Bang happened, which led to the creation of the universe. Now as the universe is already there, it cannot be re-created without it first being destroyed which will again lead it back to the step zero. It is also the most widely used word by us nowadays. ‘Nothing’ is what we do most of the times. It just may be the profession of a huge number of people in the world. Some love doing it and some are forced to it because of certain circumstances. To speak of it, at some point of time or the other all of us want to just sit back, relax and do nothing. This is what ultimately everyone’s goal is, this is what we work hard for all our lives. We all study hard to make a good career so that we can earn a lot of money and then just sit back and enjoy without having to do anything, which means being happily retired. It can also be used to hide our feelings and thoughts from the others. When we don’t want to discuss or talk about anything, we simply sum it all up in just this one word and the topic ends. Another form in which this word...

Words: 360 - Pages: 2

Free Essay

Nothing

...October 2013 If you are chasing your tail, you are busy doing a lot of different things but not achieving very much. Examples: I've been chasing my tail all day, but I haven't got anything done! What a waste of a day! Organising a meeting for next week has been impossible. I've been chasing my tail trying to sort out a date, venue and agenda... I'll try again tomorrow! * Putting out fires 15 October 2013 The phrase putting out fires means dealing with many small problems, usually at work. Though the problems might be small, they need to be solved quickly before they become bigger ones. Examples: Sorry I didn't have time to meet you for lunch today. I was busy at work all day putting out fires. Sometimes it feels like you get nothing done in the office – you need to spend the whole day putting out fires. * Ride a wave 10 October 2013 If you ride (on) a wave of something, you benefit from a period of success and/or popularity. Examples: The candidate is riding on a wave of popularity and is expected to win the election. British athletes rode a wave of patriotism during the London Olympics, winning more medals than the country ever had before. * Blow your own trumpet 8 October 2013 If you blow your own trumpet, you are boasting about your achievements and abilities. Examples: He's always blowing his own trumpet - it's so boring! Why can't he be more modest about his abilities? You've got to blow your own trumpet a bit more, otherwise you......

Words: 2045 - Pages: 9

Free Essay

Nothing

...nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in here nothing in......

Words: 360 - Pages: 2

Premium Essay

Nothing

...Edition I" b. Co-writer of a 1017 page book entitled "Human and Disaster" c. Writer, Al Qussie International Contracting Est. Administration Policy & Procedure Manual d. Writer, Al Qussie International Contracting Est. Human Resources Policy & Procedure Manual e. Writer, Al Qussie International Contracting Est. Technical Affairs Policy & Procedure Manual Despite the present condition he has acquired in which he was diagnosed with a neuromuscular disease, Amyotrophic Lateral Sclerosis also known as ALS for nearly six years now, it has not hindered him to stop what he has been used to do six years ago, but rather, he became more of a fighter in his own right and stronger to fight such disease. It only proved one thing that nothing can stop and put a good human being down. He is not only a man of conviction but also, a man of wisdom and virtue. Among other companies that he is a member of are the following: 1. Board Member, Mansur General Dynamics, Riyadh, The Kingdom of Saudi Arabia 2. Board Member, Saudi Export Company, Public Holdings Company, Riyadh, The Kingdom of Saudi Arabia 3. Board Member of Al-Ramleh Medical Company Olaya Medical Center (OMC) 4. One of the Founders of King 'Abdal-Aziz & His Companions Foundation for the Gifted 5. Member, International WHO'S WHO of Professional (The Ultimate Professional Directory)...

Words: 409 - Pages: 2

Free Essay

Nothing

...There's nothing to say about nothing. Still, some people make a fuss about it. Among spiritual seekers, there's a lot of talk about "becoming nothing". On this site about nothing, we're not going to talk about "nothing", because "nothing" can't be talked about. When people talk about "nothing", they're not really talking about nothing, they're talking about something. It's not a real nothing, it's a "nothing" they can hold in their mind. It's a nothing that feels like something, perhaps a black hole, perhaps a lonely place. They have words for it, perhaps "void", "emptiness", "nothingness". Nothingness is not nothing. It comes and it goes, so it's got to be something. You can look at it. You can hold it. You can throw it out. And when you throw it out, what's left?... ...And that's all we're going to say about that. This little introduction has nothing to do with the articles on the site. It's just here to confuse the philosophers and perhaps intrigue a few people with a genuine interest in nothing. This is a site about nothing. We hope you enjoy it. Perhaps you'd like to start with a 25-second playful video clip about a show about nothing? love numbers. And I have always loved computing. That's the whole reason computers have had such a strong pull on me since 1981, when my mom's boyfriend decided I should have my first computer: a Sinclair ZX 81. I would like this section to be about numbers, computing and computers. At the moment, it's all about computers...

Words: 272 - Pages: 2

Free Essay

Nothing

...Nothing In old American Western movies, black is the color worn by the antagonist while white represents the purity and goodness of the hero. While the scenarios and dialogue of Western films may be archaic, the symbolism of light and dark colors is still prevalent today; the connotations of a dim corner or a black cat contrast sharply against white images of angels or wedding brides. Evolutionally, humans view the sun, the most basic source of food and thus survival, as a crucial source of light, warmth, and protection. With darkness comes coldness and a fear of the unknown. In the dark, man is reminded of how alone and insignificant a life is in the vast universe. Ernest Hemingway often employs darkness in his works to convey the meaningless of existence that looms over man. Not totally void of optimism, his stories also present rays of hope that reach the reader often through literal descriptions of light. Such is the case in Hemingway’s short story, “A Clean, Well-lighted Place,” which focuses on two waiters at a café. The young waiter impatiently hurries along the last customer, an old man drinking alone, while the older waiter sympathizes with the perceptibly forlorn man. What appears to be a tale of despair and loneliness actually offers hope and strength through a quiet hero. Hemingway’s “A Clean, Well-lighted Place” focuses on the nothingness of existence and invokes in the reader a grim realization of the inevitable loneliness of life. However, hope......

Words: 2642 - Pages: 11

Free Essay

Nothing

...simply by my dad accepting a job in Pakistan. Resulting me being more close to my relatives, removing the prejudices about Pakistan and, gradually loving my motherland. In May 2004 my dad got a job from Karachi. Both my parents missed Pakistan very much, having all their brothers and sisters there and not having met them for ten years really made them homesick. My dad instantly accepted the job without even considering how I felt about it. Egypt was my home for ten years, the place where I had all my friends and spots where we hung out. The idea of moving to another country 5000 km away scared me. Starting from scratch, making new friends, learning a whole new language and the things I heard about of Karachi really frightened me. There was nothing that I could say or do that would change my parents mind. After a month we moved to Pakistan. It was the first time I was in Pakistan and was entirely different from what I had expected it to be. The first thing my parents wanted to do was visit all of their brothers and sisters. Most of my cousins are of my age, at first I wasn’t excited to meet my cousins but after having met them I realized that nice they were, we had many common interests. Over the short span of few months I and my cousins became very close. I never realized how essential cousins were until I met them Before moving to Pakistan I was curious to know more about it. I opened my computer and searched for Pakistan specially Karachi, the things I found on the net......

Words: 709 - Pages: 3

Free Essay

Nothing

...have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to give I have nothing to......

Words: 425 - Pages: 2

Premium Essay

Nothing

...Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to graduate Nothing is going on here I just want to view this paper so that I can do my own report that is due in about 6 hours and I really need this class in order to......

Words: 333 - Pages: 2

Free Essay

Nothing

...– rest 30 sec (for both side) * Do this for 2 rounds. Slowly increase to 3 rounds if you can. Hollow hold 30 sec followed by 30 sec rest, 5 rounds. Youtube has a lot of great core workout. Take a look at this one – LINK. Recon ron Pull-up Programme When you can do at least 6 proper pull up, start with this programme. The review of it is not bad. The website doesn't list the directions or specifically what you need to do however. At the top you'll notice it says WEEK 1, 2, 3, 4, etc. During each week you will perform 5 sets of the number of reps listed in the column, for example in week 1 you will do 6 reps on the first set, 5 on the second set, etc. You do this Monday through Saturday and on Sunday you take the day off and do nothing to allow yourself to recover from the previous week. Then you'll move on to week 2, however in MY (online author) personal experience I found that it moved a little too quickly, so I spent 2 weeks on week 1 before moving to week 2 where I spent another 2 weeks before moving on to week 3. If you're stuck on a certain week and you've been stuck there for more than 2 weeks without being able to improve to what's required on the next step, then take 5 days off and don't do a single pull-up. Pre-recon ron pull-up programme You can do this concurrently with the strength training workouts. Ask me if you have any questions....

Words: 830 - Pages: 4

Free Essay

Nothing

...Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here is nothing Here......

Words: 344 - Pages: 2