Role of Autotrophs and Heterotrophs

Role of Autotrophs and Heterotrophs Bacteria are unicellular micro-organisms that are found everywhere on earth. They are classified under prokaryotes. Prokaryotes are organisms which do not have a membrane bound nucleus unlike eukaryotes which possess a well formed nucleus. Though the bacteria do not possess the nucleus, they have genetic material in their DNA. The bacterial DNA is found in their cytoplasm. Though bacteria can cause diseases, only a small percentage of bacteria do so. The rest of the bacteria are harmless. The pathogenic bacteria are called parasitic bacteria and they thrive on the nutrition of other living matter for their survival. On the other hand, the saprophytic bacteria lead a symbiotic relationship with other living matter and do not cause any harm. Bacteria can be classified under various categories. They can be classified according to shape, nutritional and oxygen requirements, staining characteristics, motility, presence of cell wall and spore formation. Based on the nutritional requirements, they are classified in to: Heterotrophs Autotrophs Heterotrophic bacteria Heterotrophic bacteria grow on organic substances formed by animals and plants. They break down complex organic substances from these sources and derive carbon. Heterotrophic bacteria are divided in to Photosynthetic heterotrophs- These utilize the energy of light Chemotrophic heterotrophs These obtain energy from oxidation reduction reactions. The heterotrophic bacteria secrete enzymes which act on the complex organic substances and derive energy. Most of the heterotrophic bacteria are aerobic organisms and they need oxygen for their survival. Based on their relation with the energy sources they are again divided in to Saprotrophic bacteria- These bacteria derive nutrition from dead tissues. These are the common types of heterotrophs Saprophytic bacteria These bacteria live in close association with another species like plants and both of them get benefited. Most of the saprophytic bacteria live in association with the roots of the plants. The bacteria convert the atmospheric nitrogen in to nitrates which is utilized by the plants which in turn supply carbohydrates to the bacteria for their survival. Parasitic bacteria These bacteria live in close association with another species like plants and animals and derive their energy in expense of them. Heterotrophs exhibit two basic strategies for deriving energy from the organic substrates Fermentation In this process, the organic substrate acts as both electron acceptor and electron donor. There is no requirement of oxygen or other electron acceptor. Fermentation yields lesser energy (58 kcal/mole) Respiration This process requires external electron acceptor. The most common electron acceptor is molecular oxygen. When oxygen is used, the process is called aerobic respiration. If nitrates and sulphates are used, the process is called anaerobic respiration. Respiration yields more energy (686 Kcal/ mole). Most of the carbon in the atmosphere is derived by the process of respiration. 40%-80% of the respiration occurs under the soil. Autotrophs Autotrophic bacteria are organisms whose sole source of nutrition is carbon dioxide. They need only water, inorganic salts and carbon dioxide for growth. They are divided in to Photosynthetic autotrophs These bacteria utilize energy from light and are anaerobic organisms. This common among the two types and are quite diverse. These include cyanobacteria, green sulfur bacteria, purple sulfur bacteria, and purple non-sulfur bacteria. Suphur bacteria utilize hydrogen sulphide whereas others utilize water for nutritional process. Chemosynthetic autotrophs These derive energy from oxidation of inorganic materials like iron, sulphur, ammonia and nitrite. These organisms are anaerobic. These are usually found deep under the water and they are responsible for the food chain under the water. They derive the inorganic substrates from the volcanic vents. Soil biology Plants are terrestrial organisms and they obtain most of their nutrients from the soil. Animals derive energy indirectly from plants and other animals. This requires utilization of many elements such as inorganic compounds from the environment which are converted in to organic substances before they can be used as energy. The cycling of these elements is catalyzed by the bacteria present in the soil. Soil is the upper most layer of earth which varies in depth from a few inches to over twenty feet. The type of the soil depends on the four factors including the parent rock, the climate, the age and the biological factors like plants, bacteria and organic substances. Most of the biological activity occurs at the surface. Most of the organic substances are found in the upper layer or the upper horizon. Majority of the bacteria are found in the upper six to twelve inches of soil. Both autotrophic and heterotrophic bacteria are found in the soil. Among the two heterotrophic bacteria are more commonly found in the soil. The heterotrophic bacteria in soil belong to the order Eubacteriales and Actinomycetales. The Actinomycetales are represented by the genera Streptomyces, Nocardia and Micromonospora. These bacteria have an earthy odour. Maximum bacterial growth and activity in the soil are found around the roots of the plants. This region is called rhizosphere. Almost all the ecological interactions occur in this region. These interactions could be favorable, unfavorable, indispensable and sometimes lethal. The most important function of the soil microorganisms is to decompose various kinds of organic matter. As said earlier, cycling of elements is done by bacteria. This is done to make the elements available for reuse. The elements are usually found in the reduced state inside the cell. When they are mineralized, they are in an oxidized state. They serve three functions They form the basic components of the cell They provide energy They act as electron acceptors during oxidation reactions Bacteria are involved in three types of cycles in the cycling of the elements necessary for energy Carbon cycle Nitrogen cycle Sulphur cycle Carbon cycle About 50% of the dry weight of all living organisms is composed of carbon. The ultimate source of this organic carbon is the atmospheric carbon dioxide. Role of heterotrophs Reduce carbon dioxide by photosynthesis Fix carbon dioxide from preformed organic compounds Decompose the dead tissues of animals and plants and release the elements to be used again Role of autotrophs Reduce carbon dioxide by photosynthesis Utilize carbon dioxide from dissolution of carbonates and bicarbonates Nitrogen Cycle Nitrogen is the most important structural element of all living organisms. Though it is abundant in nature, it cannot be utilized by the plants and animals. The nitrogen cycle is concerned with incorporation of atmospheric nitrogen and organic nitrogen of dead plants and animals on to forms that are usable by higher organisms. Bacteria, both heterotrophs and autotrophs are involved in this cycle. There are five processes of nitrogen cycle: Ammonification The dead animals and plants are decomposed by the heterotrophs which release protein and other nitrogenous substances. These substances are broken down in to amino acids which are split to release ammonia. This release of ammonia from organic nitrogenous substance is called ammonification Nitrification The oxidation of ammonia in to nitrates is called nitrification. This takes place by two steps. The first step called nitrosification results in the formation of nitrites which are toxic to plants. The second step is oxidation in which the toxic nitrite is converted in to the non-toxic nitrates. Nitrate reduction The reversal process of nitrification is called nitrate reduction. The nitrate is converted in to nitrate which in turn is converted in to ammonia. Many organisms can assimilate cellular nitrogen from this ammonia. Denitrification -Certain microorganisms are capable of reducing nitrates in to nitrites and subsequently to gaseous nitrogen. This process is called denitrification. Nitrogen fixation Nitrogen fixation is a process by which the bacteria both autotrophs and heterotrophs fix atmospheric nitrogen. It is symbiotic of it is done by the bacteria living in the plant roots and non-symbiotic if it is done by bacteria independently. Role of heterotrophs in nitrogen cycle Primarily responsible for ammonification Cause nitrate reduction Involved in denitrification Involved in symbiotic nitrogen fixation Role of autotrophs Involved in ammonification under anaerobic conditions. The amine that is formed is oxidized to release ammonia Exclusively involved in nitrification. The family of autotrophs called Nitrobactericeaa is involved in this reaction Cause nitrate reduction Involved in denitrification Involved in non -symbiotic nitrogen fixation Sulphur cycle Sulphur is essential for all living organisms as sulphur containing amino acids are present in all proteins. It occurs in both organic and inorganic combinations. Cycling of sulphur is similar to nitrogen cycle. Transformation between organic and elemental states and between oxidized and reduced state are carried out by bacteria. Role of heterotrophs Heterotrophs in the soil degrade the proteins in the soil and liberate sulphur. Role of autotrophs Autotrophs oxidize various forms sulphur like hydrogen sulphide. The phototrophic autotrophs oxidize hydrogen sulphide in to elemental sulphur. The chemosynthetic autotrophs oxidize sulphur in to sulphates. Sulphate is the most suitable source of sulphur for plants. This sulphate is assimilated and converted in to proteins. Fresh water biology Fresh water is defined as water containing less than 1% of salt. The different fresh water zones include ponds and lakes and streams and rivers. Ponds and lakes Ponds and lakes consists of three zones: Uppermost littoral zone- This zone absorbs direct sunlight and contains algae, snails, insects, crustaceans and fishes. Middle limnetic zone This contains planktons Lower profundal zone- This zone contains heterotrophic bacteria. Very little enter this zone and hence it is very ideal for growth of the heterotrophs decompose the dead organisms by using oxygen through the process of respiration. Streams and rivers These are water bodies which move in one direction. The characters of these water bodies change during their course. There are three parts of these water bodies source, mid stream and mouth. The place where they reach and join another water source including ocean is called the mouth. The source of these water bodies contains high oxygen levels and hence the heterotrophs thrive here very well. Near the mouth, the light penetration and the oxygen content are very less and autotrophic bacteria are found in this region. Both heterotrophs and autotrophs exist and survive in the fresh water bodies. The processes are very similar to those that occur in the soil. In the fresh water bodies, these bacteria take care of the inorganic requirements of the algae which is similar to the plants on the soil. These organisms get in to these water bodies from air, soil, sewage, organic wastes, dead plants and animals. Climatic, geographical and biological conditions bring about great variation in the bacterial population. Rivers and stream show their highest count during rainy season. Dust blowing in to the rivers and streams also contributes to many bacteria. Animals contribute to the bacterial population by bathing and dropping their excreta. Among the various cycling of elements, the nitrogen cycle is most common one occurring in the water bodies. Role of heterotrophs They act on the dead animals and plants and other organic wastes and liberate nitrogen They can cause nitrate reduction resulting in the release of ammonia Role of autotrophs The nitrosomonas and nitrobacter species cause nitrification process Involved in ammonification under anaerobic conditions. The amine that is formed is oxidized to release ammonia

An analysis of why economic sanctions are good Essay

â€Å"A person may cause evil to others not only by his actions but by his inaction, and in either case he is justly accountable to them for the injury.† John Mills OR Senator John Kerry once said â€Å"We must retool our nation to prepare for the challenge we already face to maintain our position in the global economy. And this much is certain: America will not have national security without economic security.† Therefore, I negate the resolution that: Resolved: Economic sanctions ought not to be used to achieve foreign policy objectives Definitions: Economic Sanctions- Economic penalties, such as stoppage of trade and financial transactions, imposed upon a country to force compliance with another country’s or UN’s or WTO’s demands. (businessdictionary.com) Ought- used to express obligation. Foreign Policy- the policy of a sovereign state in its interaction with other sovereign states. Objectives- : an aim, goal, or end of action. (In case of argumentation relating to resolve not confined to U.S.A) Sovereign- one that exercises supreme authority within a limited sphere. All unspecified definitions are from Merriam Webster Core Value: Societal Welfare- What is best for most of society Value Criterion- The neg shall prevail if I can prove that economic sanctions are a worthwhile method to achieve foreign policy objectives. But the aff shall prevail if, and only if he can prove otherwise†¦Ã¢â‚¬ ¦ C1: Smart economic sanctions are needed to compel foreign leaders. The resolution calls for a general ban on economic sanctions in dealing with foreign policy objectives. One of the foremost arguments against sanctions is the harm they may potentially bring. But these potential harms are mostly caused the imposition of broad, wide-ranging sanctions. But not all sanctions are harmful- there are good sanctions. The sanctions in the 21st century are targeted and narrow, not general. One of the common criticisms of economic sanctions is that they have injured civilian populations in the past. The problem with this line of reasoning is that it assumes that there is only one type of sanction to use, and that this type of sanctioning must necessarily hurt civilians. Most countries now understand that wide, indiscriminate sanction use may be counterproductive, so they take a smarter, tailored approach to economic sanctions that make sanctions more likely to achieve their policy objectives. Many countries now tailor their sanctions to specific goods. For exa mple, many countries place specific sanctions on narcotics related items or on materials that could be used to make weapons. These tailored sanctions still allow civilians to meet their basic needs, but also make it so that rogue states are unable to use their material resources to cause further harm. Additionally, economic sanctions are now being used to freeze assets and limit the travel of high ranking state officials, which puts pressure only on them to change their country’s policies. These â€Å"smart sanctions† create an opportunity for change without the harms that occurred from past sanctions. Another line of argument for the Neg is the â€Å"toolbox† argument: that the Affirmative would remove critical tools, including targeted sanctions, from the government’s disposal. This would lead to a second dilemma, this time for the Affirmative: without the carrot and stick of economic sanctions, the government is left with a feather of non-economic sanctions and the bloody spike of war. C2: Economic sanctions are necessary foreign policy tools So what are the alternatives to sanctions? More diplomacy and military action. These have the problem of being two extremes meaning that there needs to be something in the middle. Diplomacy is the most obvious alternative. It would be lovely if all foreign policy objectives could be met simply by diplomacy but with contradictory interests, this is never going to happen in all cases. Many countries, particularly dictatorships but quite often also democracies such as the US, feel they can just ignore diplomacy if it is not backed up by anything more than a verbal lashing. Diplomacy needs something backing it up. At the moment this is the threat of some form of sanction (be it direct economic sanctions or more indirect be reducing the opportunities for that countries firms to operate in your market) or military action of some kind. Using military action as a threat can be extreme. How do you move between diplomacy and on to military action without something in the middle to show how serious your country is? If a country does not believe your threats, and you don’t really want to attack him you have to be the one to back down. Providing economic sanctions creates a way of hurting him without having to go to the worse stage†¦ which is military action. Military action is the obvious ‘hard’ alternative to sanctions. However it is not always possible. This could be because of domestic politics or because there is other significant actors in the international system who would react unfavorably to you engaging in military action, or else the consequences might be too severe. There are quite a few problems with military action apart from that it cant always be used due to politics. The most obvious is that it is an immense step up from diplomacy. The country you are going to attack needs to have done something serious to be able to justify an attack. Even if it is justifiable there are problems. Military action relies upon your country being powerful and being able to engage in military action – whereas anyone can implement some form of sanctions – and it is very costly. This is not only of course in terms of monetary cost to your country but also in lives lost and destroyed. There can also me many unintended consequences. You can intend the action to be a small police action but there is no guarantee that your opponent will see it that way so he may well strike back escalating towards full scale war. At the other extreme your actions my push a country towards falling apart and becoming a failed state. Yes it provides a very powerful tool for changing a state’s behavior- but most people would believe that it is not worth keeping the possibility of military action while getting rid of sanctions. Get rid of both and you essentially have no stick at all. States do not always respond to carrots – you need to provide a big enough carrot that they can forgo a national interest after all. In the case of two interests being diametrically opposed then this cost could be immense. C3: Violation of Human Rights Natural rights of citizens are selfishly violated by corrupt leaders of governments. This impacts not only the natural rights of citizens from other countries; it also affects the natural rights of their own citizens. a. Citizens of countries oppressed by economic sanctions suffer when intended relief efforts are suppressed by their own government intercepting supplies. The citizens are never the target, but rather the behaviors of corrupt leaders. Natural rights of citizens are denied when a corrupt leader interrupts the harmonious relations and it becomes necessary to impose sanctions. Further, I extend my VPC in that when the naturals rights of other nations are infringed upon by these corrupt leaders, political justification demands punishment in the least destructive manner after diplomacy has failed. b. Citizens are justified to demand their natural rights which are being denied to them by the very government which is supposed to protect them. When corrupt leaders give in to decency and cooperate, the sanctions go away. Sanctions are nothing more than a legitimate form of punishment to achieve a defined and acceptable code of behavior. Natural rights of citizens are denied when a corrupt leader interrupts the harmonious relations and it becomes necessary to impose sanctions. Further, I extend my VPC in that when the naturals rights of other nations are infringed upon by these corrupt leaders, political justification demands punishment in the least destructive manner after diplomacy has failed. Possible Rebuttal: Although careful studies of economic sanctions have cast doubt on their effectiveness, 1 anecdote can be powerful rhetorical tools. A single important case that demonstrates sanctions’ potential allows advocates to argue that their cause is more akin to the success than to the failures. Frequently, advocates point to the case of sanctions applied in the mid-1980s against the apartheid regime in South Africa as just such a case. On the face of it, South African sanctions appear to have been successful. In response to the outrages of apartheid, many countries adopted trade and financial sanctions and a significant amount of foreign investment was withdrawn from South Africa. After the adoption of sanctions, South Africa experienced economic difficulty and numerous domestic actors commented on how the economic situation was untenable and required political change. By 1994, Nelson Mandela had been elected President of South Africa. He and other black leaders attributed to economic sanctions a significant role in bringing about the democratic transition.

What Is The Estimation Of The Forest Femining Methods

With increase in the amount, quality and accessibility of the remote sensing data on one hand, and advancement, ease of use and capability of the open source machine learning and statistical tools, on the other hand, machine learning approaches have become very popular and powerful methods for estimation of the forest biomass in the recent years. \cite{Iftikhar} By far, linear regression is the most well understood algorithm in statistics and machine learning compared to any other machine learning tools. Table 2 summarizes the studies that has been done on estimation of the biomass using LiDAR techniques. Linear mixed effects (LME) regression is the extended version of the linear regression model and applicable for the cluster data†¦show more content†¦There are several ways to select the best features. \cite{Thomas}. Also, it has been shown that selection of the number of the features for classification, neighbors and the predictors are very deterministic in the quality of the classification \cite{NLi}. Random Forest (RF) and Support Vector Machine (SVM) are two machine learning approaches that has been successfully implemented in several studies and resulted in the significantly better results compared to KNN or other regression models. For example, in the study by Fassnacht et al.\cite{Fassnacht 2014} using LiDAR and Hyperspectral data, it has been shown that RF model produce a better forest aboveground biomass prediction compared to other tested methods. RF is the ensemble classification technique based on the many random decision trees classifiers. Decision tree is the classification approach that relate the target point to the predictor based on the simple decision criteria. Decision tree can easily become unstable and result in the very complex decision boundaries, therefore Random forests are used to improve the accuracy of the prediction and also controls the over-fitting \cite{Thomas}. It has been shown that a large number of features can be handled by RF \cite{Liai}. RF also, has been reported to have higher accuracy in predicting biomass compared to

Tips for Educators With Wheelchair-Bound Students

Dont assume that the student in the wheelchair requires assistance;Â  always ask the student if they would like your help before giving it. Its good to establish a method of how and when the student would like your assistance. Have this one-to-one conversation. Conversations When you engage with a student in a wheelchair and youre talking with them for more than a minute or two, kneel down to their level so that youre more face-to-face. Wheelchair users appreciate same-level dialogue. One student once said, When I started using a wheelchair after my accident, everything and everyone in my life got taller. Clear Paths Always assess the halls, cloakrooms, and classroom to ensure that there are clear paths. Indicate clearly how and where they access doors for recess, and identify any barriers that may be in their way. If alternate paths are required, make this clear to the student. Make sure desks in your classroom are organized in a way that will accommodate the wheelchair user. What to Avoid For some reason, many teachers will pat the wheelchair user on the head or shoulder. This is often demeaning, and the student may feel patronized by this movement. Treat the child in the wheelchair the same way you would treat all children in your classroom. Remember that the childs wheelchair is a part of him/her, dont lean or hang off a wheelchair. Freedom Dont assume that the child in the wheelchair is suffering or cant do things as a result of being in the wheelchair. The wheelchair is this childs freedom. Its an enabler, not a disabler. Mobility Students in wheelchairs will need transfers for washrooms and transportation. When transfers occur, dont move the wheelchair out of reach from the child. Keep it in close proximity. In Their Shoes What if you were to invite an individual who was in a wheelchair to your house for dinner? Think about what you would do ahead of time. Always plan to accommodate the wheelchair, and try to anticipate their needs in advance. Always beware of the barriers, and incorporate strategies around them. Understanding the Needs Students in wheelchairs attend public schools more and more regularly. Teachers and teacher/educational assistants need to understand the physical and emotional needs of students in wheelchairs. Its important to have the background information from parents and outside agencies if at all possible. The knowledge will better help you to understand the students needs. Teachers and teacher assistants will need to take on a very strong leadership modeling role. When one models appropriate ways to support students with special needs, other children in the class learn how to be helpful and they learn how to react with empathy versus pity. They learn too that the wheelchair is an enabler, not a disabler.