Endangered Species Essay Example for Free

Endangered Species Essay There are currently only 30 individual Amur leopards left in the world, the hawksbill turtle has been deemed â€Å"critically endangered†, the black-footed ferret who was once thought to be globally extinct has only a population of 1000, the black rhino was said to be â€Å"doomed to disappear from the face of the earth† in 1961, and the Saola deer has an estimated population of a few hundred at a maximum, or possibly only a few dozen at a minimum. There are many more animals who are endangered, some who are even worse off than the ones I mentioned. If we continue to abuse our power and ignore the plight of these endangered species, one day even common animals like cows or frogs will be hard to come by. These beautiful creatures are extremely important to our eco-system and food-chain and need desperately to be preserved. If we continue to refuse to acknowledge this and disregard the issue intentionally, our ecosystems will begin to collapse and we will no longer have the variety we currently do of food, medicine, animals and thousands of products will not be available to us because so many companies use materials that contain animal by-products. Also, I will give you more insight on what it means to be endangered as well as give some examples of animals who are. Firstly, we ask the question â€Å"How does the loss of animal species impact ecosystems?† There are several factors that play a role in this. All animal and plant life is part of a complex ecosystem that includes our lands and waters. Remove one or more of these parts and you damage the entire environment, sometimes beyond restoration. These ecosystems provide clean water, breathable air, fertile soils, climate control, food, medicine, energy, building materials, transportation, as well as recreational and spiritual uses. An example of an ecosystem that is suffering from a loss of biodiversity is the ocean ecosystem. It is predicted that by 2050, all species of wild seafood that are currently being fished could be collapsed, which is defined as 90% depleted. If these species collapse it would not only affect humans but other ocean species that depend on these fish as a food source. Ecological collapses like this are very serious and often cannot be fixed once destroyed without enormous amounts of effort, or not at  all. Destructive human activities have increased the rate of species extinction for 100 to 1000 times the natural rate studies done by the WWF show. According to the US fish and wildlife service, 415 species in the United States are endangered at the moment and 164 are threatened. As well, they tallied that 541 species in other countries are endangered and 50 are immediately threatened. These numbers are much too high. This loss of species will affect our ecosystem’s stability and put our entire way of life off balance, as the animals run out of resources, so will we. Moreover, this lack of biodiversity affects many aspects of our own lives, the four most affected areas are our food sources, our medicine supply, our diversity in animal species and the variety of available products. The effect on our food source is obvious. No more cows, no more BigMacs. More so than that though, even our fruits and vegetables are being affected, there are many things needed to have healthy crops, one thing is good soil for example. Worms are needed to enrich the soil and add essential nutrients to it that help plants grow. Worms are part of an intricate food-chain that is connected to humans. Even those junk foods that seem to have nothing natural in them actually do. Nearly everything at some point was a plant or an animal, it’s a cycle. Our medicines are also made from plants, especially in certain cultures. A few medicines created from plants are the bark of a white willow, which contains acetyl salicylic acid, commonly known as aspirin. It has been used for pain relief for 2,000 years. Galantamine hydrobromide, a compound derived from daffodil bulbs, is being used to treat Alzheimer’s disease. Digitalis has been used since the 16th century to treat heart disease and its derivatives are still used in modern medicine, this comes from foxglove. For the third point, even farm animal diversity is declining as accelerating species loss threatens humanity. â€Å"The accelerating disappearance of Earths species of both wild and domesticated plants and animals constitutes a fundamental threat to the well-being and even the survival of humankind†, warns the founding Chair of a new global organization created to narrow the gulf between leading international biodiversity scientists and national policy-makers. Dr. Zakri, a national of Malaysia who co-chaired 2005s landmark Millennium Ecosystem Assessment and serves also as science advisor to his countrys prime minister, cited  fast-growing evidence that we are hurtling towards irreversible environmental tipping points that, once passed, would reduce the ability of ecosystems to provide essential goods and services to humankind. Some scientists have termed this the sixth great extinction episode in Earths history, according to Dr. Zakri, noting that the loss of biodiversity is happening faster and everywhere, even among farm animals. Lastly, do you think your home is free of items that have been tested on animals and contain animal by-products? You would be surprised how many companies make their merchandise like this, using these harsh techniques. A few items I’ve found to use these techniques are Jell-O, Windex, Trojan condoms, post-it notes, mars candy bars, Band-Aids, Kleenex, Iams pet food and Vaseline. These animals can’t do a thing to better their situation. They are becoming more and more endangered, threatened and vulnerable each day, do you know what that means? To be endangered means to be threatened with a danger or by extinction. To threaten means to utter a threat against, to be a menace or source of danger to, to offer a punishment to by way of a threat, to give an ominous indication of, or indicate impending evil or mischief. Endanger is also a synonym of threaten. Lastly, the definition of vulnerable is; capable of or susceptible to being wounded or hurt, as by a weapon, open to moral attack, criticism, temptation, etcetera, open to assault; difficult to defend, or exposed to disease, disaster, or attack. We have placed hundreds of thousands of animals in a position where they are any one of those three things or worse, extinct. Meaning no longer in existence; that has ended or died out. Like the thylacine, the pig-footed bandicoot, the Steller’s sea cow, the tule shrew, the Malagasy hippopotamus, the Portuguese ibex, the Hokkaido wolf, the Syrian wild ass, as well as multitudes more. We, in a large part, are responsible for these disappearances, for the deaths of the innocent. We invade this pristine world, claiming it as our own simply by our presence. We slaughter innocent animals for their hides and their flesh. We devastate the landscape and gouge out the earth to build our monuments to vanity. Yet, still, we have the audacity to wake up in the morning and  complain about it all. Humans are a vain and horrendous species when it comes down to it, and some days, I’m ashamed to be a part of it. It’s time to clean up the mess we’ve made, time to stop ignoring everything, and time to start preserving the earth and its inhabitants, all of them, the way it should’ve been since the beginning.

Coincidence Counting With NAI Scintillation Detectors

Coincidence Counting With NAI Scintillation Detectors ABSTRACT Coincidence counting is a technique employed in nuclear medicine for PET imaging. This technique utilizes a positron emitting radionuclide that is injected into patients to track biochemical and physiological processes. The positron annihilates with an electron and emit two 0.511MeV gamma rays which are detected simultaneously by two scintillation detectors. In the experiment, two gamma ray sources, 60Co and 22Na were used with a NaI scintillation counter. A single channel analyzer (SCA) was used to count the number of voltage pulses whose height fell within the gate width. The absolute efficiency and intrinsic efficiency was obtained as a function of distance. Real and random coincidences were determined from the spectrum obtained with varying gate width and gate delay for each source. The optimum gate width obtained was 5 µsec for both sources with gate delays of 1.2 µsec and 0.2 µsec for 22Na and 60Co respectively. The real coincidences for 22Na and 60Co were found to be 200 .1  ± 2.3 and 76.5  ± 1.7 respectively. The random coincidences obtained were 25.1  ± 3.4 and 13.4  ± 2.6 for 22Na and 60Co respectively. This was determined by using the LINEST function. The percentage thus of random to real coincidences obtained in this experiment was 12.54  ± 1.85 % and 17.52  ± 3.81 % for 22Na and 60Co respectively. It was deduced that the uncertainty in determining a random coincidence was higher in 60Co than in 22Na. the magnitude of the uncertainty is as a result of fluctuations in the instrumentation. Hence the Na system is more efficient for coincidence counting and so it is useful in the PET system. INTRODUCTION Coincident counting is a radiological measuring technique that is utilised in the nuclear medicine in the PET scan whereby two photons emitted from an event are detected simultaneously by a ring of detectors. Sodium Fluoride (F18-NaF) is the positron-emitting radionuclide employed in PET for bone imaging [1]. Upon decay, the positron are emitted which travels for a short distance and under Compton’s scattering thereby loosing most of its energy. It then undergoes annihilation with an electron and emit two high energy 0.511MeV photons. The 0.511MeV photons are emitted 180 degrees apart and interact with the PET detector rings at opposite sites. [2] The detectors are made up of scintillation crystals coupled with photomultiplier tubes powered by a high voltage which produces a pulse with a height proportional to the gamma-ray energy. A SCA counts the number of voltage pulses whose height falls within a predetermined window of photon energies. Coincidence measurement is utilised when a single detector cannot produce all the information expected, as gamma rays are randomly produced, hence the need to set several detectors. Real coincidences occur when two photons are emitted in coincidence from the same annihilation event and are detected simultaneously within a certain time frame set by the gate width. Random coincidences occur when two photons emitted from different events are detected simultaneously within the time frame of the gate width. [3] The gate width determines the time window within which the simultaneous emission of the gammas are detected. The optimum gate width therefore will ensure that the maximum number of real coincidences are detected to minimise the events of random coincidences. In the ideal situation when the gate width is zero the real coincidences can be observed, and with an increase in gate width the random coincidences can be observed. In the PET scan, this will ensure efficiency of the coincidence system. The need for the gate delay is to enable the second pulse to be detected within the time frame of the gate width and this is usually a minute time frame. It takes into account the minute fluctuations that occur at time of pulses. By alternating the gate delay and gate width, the rate of coincidence can be determined. In this experiment the two sources used were 60Co and 22Na. 60Co emit two gamma rays upon beta decay at energies 1.3325Mev and 1.1732MeV with 60Ni daughter nuclide. The 22Na undergoes a beta decay and electron capture decay with the emission of a 1.275MeV gamma photons and two 0.511Mev upon interactions with the detector material. The positron from the beta decay of 22Na annihilates an electron of the detector and emit the two gammas at 0.511Mev energies at 1800. The coincidence counting system records just a certain portion of events depending on the solid angle as a function of distance. Coincidence counting as a function of distance is maximum in the middle and zero at the edge [4]. The photons can undergo several interactions in the detector before they are detected and that render the detector inefficient and so there is the need for its efficiency to be determined. The efficiency can be classed into two as absolute and intrinsic efficiencies and they are defined as Absolute efficiency ÃŽ µabs = Number of pulses recorded [3] Number of radiation quanta emitted by source Intrinsic efficiency ÃŽ µint = Number of pulses recorded [3] Number of radiation quanta incident on detector These efficiencies are related by ÃŽ µint = ÃŽ µabs * (4à ¯Ã¢â€š ¬Ã¢â‚¬  /à ¢Ã¢â‚¬Å¾Ã‚ ¦) [3] where à ¢Ã¢â‚¬Å¾Ã‚ ¦ is the solid angle of the between source and detector. The solid angle is dependent on the distance between source and detector (d) and the radius of the detector (r) and it is determined by the this equation, à ¢Ã¢â‚¬Å¾Ã‚ ¦ = 2à ¯Ã¢â€š ¬Ã¢â‚¬   1 d [3] √d2 + r2 To determine the efficiency of the coincidence system, the absolute efficiency for real and random coincidences were also determined for both sources based on the equations below. ÃŽ µabs for real coincidences for 22Na = ÃŽ µabs * ÃŽ µint ÃŽ µabs for random coincidences for 22Na = (ÃŽ µabs)2 * Activity * Intensity * Time ÃŽ µabs for real coincidences for 60Co = ÃŽ µabs * ÃŽ µabs ÃŽ µabs for random coincidences for 60Co = (ÃŽ µabs)2 * Activity * Intensity * Time METHOD Two NaI detectors coupled with photomultipliers with high voltages and preamplifiers were used for this experiment. The inputs were connected to spectroscopic and SCA amplifiers. Detector 1 was first corrected for background by counting for 5 minutes. The 22Na gamma ray source was varied with distance and the absolute efficiency of the detector was determined as a result. Detector 2 was introduced and set at a distance of 10cm apart from Detector 1. 22Na was positioned in the middle and the counting was set to 5 minutes. The gate width and gate delay were varied and their spectrum observed. The experiment was repeated for the second gamma ray source, 60Co. The optimum gate delay was determined and varied with the gate width to obtain the optimum gate width. A linear graph of count rate against gate width was obtained that showed the real and random coincidences based on the slope gradient obtained. The percentage ratio of the random to real coincidences were determined and the uncertainty associated with the experiment was also determined. RESULTS/DISCUSSION The background spectrum was corrected in the count reading for both sources. The background radiation is as a result of scattered radiation associated with the experiment. The absolute efficiency of the detector was determined for both sources as shown in Figure 1 and Figure 2 and Table 1a 1b and Table 2a 2b for 22Na and 60Co respectively. The absolute efficiency was obtained using the formula Absolute efficiency = Sum of count Intensity x Activity Figure 1: Absolute efficiency as a function of the distance between the 22Na source and detector Figure 2: Absolute efficiency as a function of distance between the 60Co source and detector The 22Na revealed a gradual decrease in efficiency with increasing distance, whereas 60Co revealed a rapid drop in efficiency as a function of distance. 60Co revealed lower absolute efficiencies since the measure of the number of pulses obtained by the 60Co was less than the number of photons emitted by the gamma ray source. This could have been due to Compton scattering reducing the number of photons actually detected as a pulse. The 22Na however revealed quite high absolute efficiencies and so can be confirmed that the detector was efficient in detecting the 22Na than the 60Co. The intrinsic efficiency was determined using the equation below. ÃŽ µint = ÃŽ µabs * (4à ¯Ã¢â€š ¬Ã¢â‚¬  /à ¢Ã¢â‚¬Å¾Ã‚ ¦) The solid angle was determined for the detector when the distance between both detectors was varied between 5cm to 20cm and the radius of the detector was measured as 10cm. This is shown in Tables 3 and 4 and Figures 3 and 4 for 22Na and 60Co respectively. Figure 3: Intrinsic efficiency as a function of distance between the 22Na source and detector Figure 4: Intrinsic efficiency as a function of distance between the 60Co source and detector The intrinsic efficiency for 60Co was lower than 22Na. It can be deduced that the number of 60Co photons incident on the detector was more than the number of pulses recorded. Hence signifying that the detector was not efficient in detecting the 60Co. The 22Na however displayed high intrinsic efficiency almost approximating the maximum value for intrinsic efficiency. The intrinsic efficiency were found to be fluctuating with the highest being 0.9898 and 0.3872 with a solid angle of 1.3029 at 13cm distance from detector for 22Na and 60Co respectively. This is as result of the detector’s geometry detecting the photons at different solid angles. The solid angle determines how much of the photons can be detected as a function of distance. The overlap of the error bars signifies the uniformity of the errors. The probability of a 0.511MeV gamma travelling in the direction of the detector and being absorbed by it, will imply that the second 0.511MeV will also travel in the correct direction. Both detectors detecting the two 0.511MeV gammas can be determined to yield the absolute efficiency for real coincidences. This can be deduced from the notion that photons travelling in the right direction will be absorbed in the right direction by both detectors. The results of absolute efficiencies for real and random coincidences for 22Na and 60Co is shown in Table 5 6 and Figure 5, 6, 7 8. The efficiencies for both sources decreased with distance and it was lower for 60Co. The absolute efficiency for random coincidences was however for both sources than the absolute efficiency for real coincidences. It can thus be inferred that the absolute efficiencies for real coincidences for both 22Na and 60Co yields less probability of detection of real coincidence with 60Co as compared to the 22Na. The abso lute efficiencies for random coincidences was however comparable for both sources as the probability of detecting the second event within the gate width is possible for both sources. Figure 5: Absolute efficiency for real coincidences as a function of distance for 22Na Figure 6: Absolute efficiency for random coincidences as a function of distance for 22Na Figure 7: Absolute efficiency for real coincidences as a function of distance for 60Co Figure 8: Absolute efficiency for random coincidences as a function of distance for 60Co The gate delay was varied with gate width to obtain the optimum values of delay and width. The optimum gate delay was obtained as 1.2 µsec and 0.2 µsec for both 22Na and 60Co respectively and was used for the experiment. A linear graph of count rate as a function of gate width was obtained and a fixed gate width was obtained as shown in Figure 5 and 6 and table 7 and 8 Figure 5: A linear graph of count rate as a function of gate width applying a 1.2 µsec gate delay for 22Na Figure 6: A linear graph of count rate as a function of gate width by applying a 0.2 µsec gate delay for 60Co Real coincidences occur on the intercept of the linear slope gradient, whereas random coincidences can be found with the slope. For 22Na the optimum gate width obtained was 5 µsec. The graph of count rate as a function of gate width yielded a slope gradient of y = 5.019x + 200.15. By applying the optimum gate width and correcting for the gate delay, the real and random coincidences were determined using the LINEST function. The real coincidences was found to be 200  ± 2.3 whereas the random coincidences was found to be 25.1  ± 3.4. The percentage thus of random to real coincidences obtained in this experiment was 12.54  ± 1.85 %. This gives the value of pure coincidences that are not dependent on gate width. For 60Co, the optimum gate width was 5 µsec. The graph of count rate as a function of gate width yielded a slope gradient of y = 2.6801x + 76.483. When the optimum gate width was applied whilst correcting for the minute gate delay, the real and random coincidences were determined using the LINEST function. The real coincidences was found to be 76.5  ± 1.7 whereas the random coincidences was found to be 13.4  ± 2.6. The percentage of random to real coincidences obtained in this experiment was 17.52  ± 3.81 %. The above results was compared with the measured values obtained from the graph. The intercept gave the real coincidences as 200.15 and 76.48 for 22Na and 60Co respectively. The point of data convergence on the straight line gave the optimum gate width and the count equivalent was found as 225.28 and 90.02 for 22Na and 60Co respectively. The difference between this value and the real coincidences yielded the random coincidences as 25.13 and 13.56 in 22Na and 60Co respectively. Hence the percentage ratio of the random and real coincidences was obtained as 12.49% and 17.73%. This is equivalent to the values obtained from the calculated coincidences with the differences being due to uncertainties. The uncertainties with this experiment were with the NaI detector which contributed to scatter around the cover. The count rates resulted in some uncertainties as well and has been sown in table 8 for both detectors. The solid angle presented an uncertainty as the measurements for the detector could incur a large margin of errors. From all the results synthesized for both sources it could be gathered that the 22Na was an efficient source for coincidence counting compared to the 60Co. This is as a result of the geometry of the detectors as the Co system does not show a coincidence system and so there is more likelihood of a random coincidence than a real coincidence as compared to the Na system. This concludes that the 22Na will be efficient in a PET system, hence the reason for positron emitting radioisotopes being used in the PET system to ensure the maximum number of coincidences are being detected CONCLUSION The experiment was performed to examine the coincidence counting in two gamma ray sources and to determine the real and random coincidences as a function of gate width. The optimum gate width obtained was 5 µsec for both sources with gate delays of 1.2 µsec and 0.2 µsec for 22Na and 60Co respectively. The real coincidences for 22Na and 60Co were found to be 200.1  ± 2.3 and 76.5  ± 1.7 respectively. The random coincidences obtained were 25.1  ± 3.4 and 13.4  ± 2.6 for 22Na and 60Co respectively. This was determined by using the LINEST function. The measured count rates was also determined from the graph and resulted in real coincidences for 22Na and 60Co respectively as 200.15 and 76. 48 and random coincidences of 25.13 and 13.56. The percentage thus of random to real coincidences obtained in this experiment was 12.54  ± 1.85 % and 17.52  ± 3.81 % for 22Na and 60Co respectively. This gave the quality of the uncertainty in the coincidence system. It was deduced that the uncertainties in determining a random was higher in 60Co than in 22Na hence the Na system is more efficient for coincidence counting and very useful in the PET system. REFERENCES [1] The detection of bone metastases in patients with high-risk prostate cancer:99mTc-MDP planar bone scintigraphy, single- and multi-field-of-view SPECT,18F-fluoride PET, and18F-fluoride PET/CT.Even-Sapir et al, J Nucl Med(2006)47:287–97 [2] The Physics of Medical Imaging, ed. S. Webb. IoP publishing [3] Radiation and Detection Measurement, Glen N Knoll, 3rd Edition [4] Coincidence Counting, E. K. A. Advanced Physics Laboratory, Physics 3081, 4051 APPENDIXES Table 1a: Counts rate as a function of distance between source and detector for 22Na Table 1b: Absolute efficiency as a function of distance between source and detector for 22Na Table 2a: Counts rate as a function of distance between source and detector for 60Co Table 2b: Absolute efficiency as a function of distance between source and detector for 60Co Table 3: Intrinsic efficiency as a function of distance between source and detector of 22Na Table 4: Intrinsic efficiency as a function of distance between source and detector for 60Co Table 5: ÃŽ µabs for real and random coincidences as a function of distance for 22Na Distance(cm) ÃŽ µabs à ¢Ã¢â‚¬Å¾Ã‚ ¦ 4à ¯Ã¢â€š ¬Ã¢â‚¬   ÃŽ µint ÃŽ µabs for real coincidences ÃŽ µabs for random coincidences 5 0.09940 3.473 12.57 0.35967 0.0994 48.7255 10 0.05091 1.8403 12.57 0.347637 0.0509 12.8015 13 0.04015 1.3029

Use of gis and remote sensing data

Use of gis and remote sensing data INTRODUCTION Studies have shown that only few landscape on earth surface remain unaltered or in their natural state and is due to immerse demographic pressure and anthropogenic activities (Zubair, 2006). Competition between species and human beings has been the leading cause of land cover change in the world. This factor is substantially verified by the conversion of forest land to other uses like farmlands for agriculture, industry urban development, infrastructure, recreation and others. (Brown, 2004) Forest plays an important role in the overall stability of carbon in the atmosphere mitigating or exacerbating the effects of global warming. Therefore, Forest carbon sequestration can help to minimise the raise of greenhouse gases in the atmosphere, (Juan and Louis, 2009) It is therefore important to note that forests are counted among the worlds chief carbon sinks contributors. They store more than 289 giga tonnes (Gt) of carbon in their litter, deadwoods and soil and these are more than the carbon found in the atmosphere. Globally, there was decrease in carbon stocks of forest biomes of 0.5 Gt a year between 2000 2010 and was mainly due to deforestation, (FAO, 2010) â€Å"Globally, about 13 million hectares of forests were changed to other uses an some were lost through natural causes each year, that is between 2000 and 2010 as when compared to almost 16 million hectares per year during the 1990s† (FAO, 2010). The biggest losses or the highest net annual loss of forests from 2000 to 2010, are in South America and Africa with four and 3.4 million hectares respectively. On the other hand, a recent study by the Food and Agriculture Organisation (FAO, 2010) reveal that generally, the destruction of tropical forest for agricultural activities has decreased over the last ten years, but the rate of deforestation for other activities continues to increase at an alarming high rate. The tropical rain forests are significant component of the climate system and play an important role in the total carbon-dioxide exchange balance of the earths plant cover. McGuffie et al. (1995) suggested that the existence of tropical rain forest has a great influence on regional climate and as such tropical deforestation has been seen to affect the climate of different parts of the world. Tropical forests make up the most diversified ecosystems in the world with the highest biomass per square metre especially in the lowland rain forest (McGuffie et al. 1995). But much of the forest areas have been subjected to continuous depletion as a result of artificial or natural factors. The annual rate of destruction to the rain forest seems to be increasing and could double in the next few decade (Myers, 1992). The tropical rain forest in Nigeria is also undergoing severe exploitation as a result of population growth, urban expansions, mismanagement and socio-economic development. The process of deforestation is mainly caused by clearing of forest land for agricultural activities, logging, fuel wood, mining and industrialization etc. Like most tropical regions of the world, deforestation remain a key issue on environmental, ecological and socio-economic challenge in Nigeria (Uneke and Ibeh, 2009) Nigeria has the highest deforestation rate of primary forests from the revised deforestation figures obtained from Food and Agriculture Organisation of the United Nations (FAO). Between 2000 and 2005 the country lost 55.5% of its primary forests and contributes 3.3% in the world therefore ranked the world highest rate deforested country. Since 1990 the country has lost a total of 6.1 million hectares or 35.7% of its forest covers and this has result in the lost of its primary or old forest at a faster rate. Since 2000 report have shown that Nigeria is losing at an average of 11% of this primary forest and which has double the rate of 1990s. Moreover, the Nigeria First National Biodiversity Report-NFNBR (2001) estimates the rate of deforestation at about 5% annually compared with 0.6% globally. The major causes of deforestation in Nigeria include corruption, overpopulation, urbanization, population growth, inequitable distribution of wealth, and poverty (Ayodele, 2010).The United Nations Framework Convention on Climate Change has stated that the overwhelming cause of deforestation is agriculture. It stated that subsistence agriculture accounts for 48% of deforestation, while 32% of deforestation results from commercial agriculture. Wood-fuel is said to account for 5%. Forest biomass has remained the most common source of household energy in Nigeria, meeting 80% of domestic energy requirements. In 1992, alone, forest wood and charcoal products were estimated at 55 million tons, suggesting that much forest woods are been used for domestic purposes. According to Choji (2005), more than half of 9.6 million ha of rain forests in the south of Nigeria have been used to meet the demand for fuel wood in rural and urban neighbourhoods. Compared with the costs of petroleum product, fuel wood is cheaper than any commercial fuel substitute and this has, over the years, increased forest depletion. He further noted that this appears to have propounded effect on the environment and the sustainability of the forest. Similarly,(Uyigue and Agho,2007) also noted Logging, urbanization, oil exploitation, subsistence agriculture, and the collection of fuel-wood among all are noted as foremost causes of deforestation in Nigeria. Therefore an attempt will be made in this study to map out the status of changes in the forest areas of Niger Delta Region of Nigeria between 1987 and 2002 using both remote sensing and GIS. Research Question: Is there change in forest cover in Niger Delta Region of Nigeria between 1987 and 2002? Aim: To identify and map out changes in forest cover of Niger Delta Region Nigeria and adopt suitable methods in detecting such changes using remote sensing data and GIS techniques Objectives: * To analyze the Spatio-Temporal change in forest cover using classification methods * To apply different change detection techniques and identify changes in forest cover * To map out areas of changes * To analyze the effects of land cover change in the region and to suggest some recommendations. THE STUDY AREA The study area is located in the Atlantic coastline of southern Nigeria 5 °30N 6 °30s. Niger Delta region falls within the tropical rain forest zone of the world. Its named as the second largest delta in the world occupying about 450 kilometres spanning coastline. The region is describes as largest wetland in Africa and covers over 2000 square kilometres that mainly consists of lakes, rivers and creeks. Ecosystem is diverse and highly supportive to numerous species both aquatic and terrestrial and human life, (Uyigue and Agho, 2007). The region is vegetation cover is mainly swamp forest which can be further divided into two classes; the Mangrove and the fresh water forest. The Mangrove spanning around 1900 square kilometres and the largest in Africa,(Uyigue and Agho,2007). The main features of its geography include extreme blocks of luxuriant high forest that occur in the region. It has the largest ply-wood and veneer plants in West Africa and has known as a centre for saw milling. The area consist of three types of forest strata of tree tall (120m high), moderate (50m 100m) and those below 50m.Some common trees found in the area are obeche, abura, sepele and mahogany. http://www.britannica.com/EBchecked/topic/523642/Sapele States found around the region include Niger Delta, Port Harcourt to south western states Oyo, Osun and Lagos state. The region has heavy precipitation of between 1824 millimetres and over 4000 millimetres along the coast. Rainfall falls throughout the year with a shorter break in August and longer one from December to January. Trade winds originated from Atlantic Ocean of the southern part of the country is responsible for Nigerian rainy seasons Nigeria. The region has an equatorial monsoon climate; temperature ranges between 28 °C (82.4 °F) and 26 °C (78.8 °F) (Wikipedia). Map showing the location of the study area LITERATURE REVIEW Landsat is an important component in the climate system, and plays a key role in monitoring global change and is primary source of medium spatial resolution earth observation used in decision making (Gyanesh Chandera et al., 2009). Remote sensed imagery provides accurate understanding and comprehensive way of modelling and projecting land change (Elvidge et al., 2004) With the introduction of landSat5 1984 and landSat7 ETM+ 2002, this has marked a significant advance in remote sensing through obtaining more sophisticated advance sensor; improve acquisition and transmission of data and more rapid processing at a highly processing facility (Gyanesh Chandera et al., 2009). Change Detection is one of the main applications of remote sensed data. A considerable amount of literatures has been published by the researchers in trying to quantify and assess land cover change detection Change detection is the process of identifying differences in the state on an object or phenomena by observing it at different times, over a certain period of time. (Singh, 1989) cited in (Lu et. al., 2004) A quite number of change detection techniques have been summarised by many authors in an attempt to find out land cover changes over time. Lu et al., (2004) categorizes these techniques into seven classes ranging from simple algebras to more complex and advance ones namely; Algebra which include image rationing, image differencing vegetation index differencing, Change vector analysis, others in the category includes transformations, classifications, Advance models, Biophysical parameter methods and those that involve the combination of both GIS and remote sensing data for analysis Change detection have gained wide range of application in the field land use land cover change; Peiju et al., (2010), reported to have used multi- temporal remote sensing Landsat TM to monitored urban land cover and vegetation change in Xuzhon city between 1987 2007, the result of the statistical analysis show that build up areas have obviously increase while farmland have seen in a continuous loss due to urban growth and human activities. Zubair (2006) detects changes in land use land cover in Kwara state Nigeria between 1972 1nd 2001 using change detection techniques of GIS and remote sensing data, the result of the analysis show that there was rapid growth in the built up areas and was a result of population pressure. He noted that there was steady reduction in forest cover in the study area and further predicts continues loss in subsequent years. Chen, 2002, noted the use of GIS and remote sensing techniques and monitors changes along the coastline zone of Korea, the result of t he study show that both human and natural factors are responsible for the change and this has on the other hand impacted the sustainable development of the region. Janifer et al., 2010, monitors forest change in the landscapes area of Chile between 1975 and 2008, the result of the study show an average rate Deforestation was -1.7% and shrub land -0.7%, however agriculture and timber plantations increased at annual rate of 1.1% and 3.3% respectively. The study concludes there is progressive lost of forest cover in the region. Moreover, in the field of Urban and environmental change; George et al., (2009), used Landsat imagery change detection methods in updating the 2001 national land cover database land cover classification to 2006, conservative thresholds based on Anderson level 1 classes were used to segregate the change vectors and determine areas of change and no change. An accuracy of 83.225% of the five selected areas achieved. Woodcock et al., (2001) noted Landsat in detecting environmental change over time, the study makes use of generalization method in monitoring large areas for forest change and conclude that method is state-of-the earth as other methods and consumes less time as other conventional methods Change detection in the field of forest or vegetation change includes the work of Chengquan et al., (2009), in the assessment of Paraguays forest cover change using Landsat observation of high resolution image showed that Atlantic forest ecosystem experienced the most loss with the 73.4% forest cover in the 1970s decreasing precipitously down to 40.4% by the 1990s and further down to 24.9% by the year 2000. Rasuly et al., 2010, noted the advantage of using GIS and remote sensing techniques to monitor the rate of forest alterations in the Arasbaran protected area using various methods, the result of the study show that about 6146.9 hectares of the area has being deforested over the past 18 years, in cooperating with the GIS also show that the lost was due to physiographic factors and they suggest to distant settlements from the protected area. Similarly Li et al., 2011, noted the advantage of Landsat Lider fusion for modelling the height of young forest. Schlerf and Atzberger (2005), estimates the structural canopy variables using hyper spectral remote sensing data INFORM â€Å"Invertible forest Reflectance Model†. Main advantage of this method is that it does not require previous calibration. Olthot el al., (2004) map out deciduous forest of ice storm damage using Landsat and environmental data in the east of Ontario, the study show a limitation in the difficulty of both remote sensing and environmental data to discriminate many levels of the deciduous ice damage, however it can be consider as a useful technique in differentiating areas of low to medium damage from the severe damage. An overall accuracy of 69% was achieved. Mapedza et al., 2003, investigate s land cover change of the forest reserve area of Mafungautsi Zimbabwe, the study show that whilst forest cover within the reserve remain the same, but however there is steadily decline outs its boundaries as a result of agricultural expansions, the collection of fuel wood and building materials demand 3.0 METHODOLOGY Pair of multi- temporal cloud free Landsat images was selected to classify the study area; 1987 and 2002, the image of image 1987 was Landsat 5 TM and the other Landsat 7 ETM+. The images were downloaded from GLCF websites in different layers and will be layer stack together using ERDAS Imagery 9.2. A subset will be collected and image enhancement is to apply using Histogram equalised to visualised features more clearly. The images were geo-reference to Universal transverse Mercator (WGS84 zone 32), and a common geo-link window covering the same geographical coordinates were then extracted from each image 3.1.1IMAGE PROCESSING TECHNIQUES: Digital image processing is classified into three classes which includes; pre-processing phase, processing phase and the post-processing phase. The pre-processing phase is the first stage in the processing technique, it involves correction of data through various means and techniques, different types of errors that are associated with any satellite images includes; geometrical error, atmospheric error and radiometric error. Geometric correction is a technique used to correct errors that are usually induced by sensor viewing, geometry and terrain variations, it involves correcting spatial distortion in an image due to earth curvature, atmosphere etc and thus giving it a real world coordinate system. The two images to be used in this study will not undergo the pre-processing phase because the two images obtained are ortho-rectified. The processing stages involve manipulation of images through the spatial enhancement and the spectral enhancement techniques. Image Enhancement; the procedure is applied in order to display effectively the tonal distinctions within various features display in the image. It normally involves techniques for increasing the visual distinctions between features to assists in visual interpretation and analysis. (lillesand et al., 2008 p482 ) Histogram -equalised stretch is going to apply to expand the DN values and also enhance the quality of the features in the image so that radiometric detail is enhanced. (Lillesand et al., 2008) 3.1.1 CLASSIFICATION ANALYSIS Supervised classification, using maximum likelihood algorithm is going to be used, supervised classification requires selection of sufficient training sample which are subsequently used to assign image pixels to the training samples that best fits the corresponding data, it separately classifies multi-temporal images, pixel by pixel. Supervised classification requires an immense amount of time and know-how in creating classified products. Moreover, the final accuracy depends upon on the value of the classified image of each date. Yueling and Xu (2010),reported to have used supervised classification technique in monitoring and driving force analysis of urban expansion in Guangzau City China and the result of the outcome shows an annual 19.7% growth rate. Post-classification comparison (PCC), is another important method that is recognized as the most effective and accurate method of detecting changes in mages with different dates and registry, the algorithm is capable of comparing the classified images pixel by pixel. The use of PCC is thus reduces the environmental and atmospheric effects associated with the temporal images and thus provide a complete change matrix (Lu et al., 2004). Accuracy assessment is the overall accuracy of the work done; it shows the proportion of ground sampling points that are correctly classified. The user accuracy shows the proportion of classified pixels in according with the actual ground types as taken from the ground truth testing data. Accuracy assessment allows you to evaluate a classified image file (Thematic raster layer). 3.1.2 CHANGE DETECTION TECHNIQUES: Change detection techniques is useful in a wide variety of applications such as; land use change analysis, monitoring shifting cultivation, assessment of deforestation etc. change detection techniques to be used for this studies will include; change vector analysis, image ratios and image differencing. These techniques have the ability to calculate area change, change rate as well as the spatial distribution changes. These techniques will involve computing the area covered by each of the two supervised classified images from the two data sources independently and compare between the two images for increase or decrease in changes that have occurred in terms of forest change cover (Lu et al., 2004). Change vector analysis is a technique that generates two outputs, the first output produced is on spectral change from the first to the second image and the second output will produce the total change magnitude per pixel, Change vector analysis is computed by determining the Euclidean distance between end points through n-dimensional change space (Lu et al., 2004). Its main advantage in terms of analyzing change detection is its ability to process any number of spectral bands desired by the analyst and capable of producing in detailed of change detection information as it defines threshold and identify change trajectories which is a good way to calculate percentage rate of change that has occurred in a particular studies. Moreover the direction of the spectral change is often relates to that type of change that had occurred (Lillesand et al., 2008). Method was used by Allen and Kupfer (2000) in conifer forest change detection. Image differencing is a change detection technique that will be used in this research to extract more information regarding the changes that have occurred in the study area; image differencing subtracts the first date image from the second date image, pixel by pixel to show the changes within the two dated images, it identifies suitable image bands and thresholds. Image differencing usually yields a better results when carried out on the intensity bands generated by transforming the RGB data sets into IHS color space. Singh (1986) applied this method in tropical forest change, similarly (Jha and Unni 1994) in forest conservation change detection. Image ratio is going to be applied because it is a simple way of trying to extract useful information from TM imagery. With image ratio technique, intensities of reflected energy recorded in one band for the pixel of a satellite images are divided by intensities in the same band for the other rectified images. Image ratios describe the color of an object, although the color only corresponds to human perception when the three visible bands of red, green and blue are considered. Image ratio is prepared by dividing the digital number in one band by the corresponding digital number in another band for each pixel, thus stretching the resulting values, and plotting the new values as an image rationing is an effective way of visualizing different types of soils because the main spectral differences in the visible and near infrared spectral regions are found in the slope of the reflectivity curves. It calculates the related quantity of registered images of different two dates pixel by pixel. Ratios for changed areas have higher values or lower ratio values whereas an area of no change tends to move towards one (1). An important advantage of this method is it tends s to normalize the impact of sun angle and shadow which has been caused as a result of external factors. (Lillesand et al., 2008 p596) Method has being used in land use mapping and change detection by Prakash and Gupta (1998) Finally, overlay operations would be made to see the changes that occur in the region. And Data is exported to GIS data base for map production. The above figure show a change detection procedure for the Landsat Images would undergo during the analysis.

Parole Should Be Abolished Essays -- Argumentative Persuasive Crime Es

Parole Should Be Abolished The procedure known as â€Å"parole† in the criminal justice system has been in practice in the United States since the late 1800’s when it was begun in a reformatory in Elmira, New York. It’s process provides for early conditional release from prison for convicted felons, after part of their prison sentence has been served, and they are found to be eligible for parole based on factors such as: conduct while incarcerated, rehabilitative efforts/progress, type of offense, and remorse for their crime. Its use has been expanded to many states, and today has become the primary way by which offenders are released from prisons and correctional institutions. Unfortunately, parole is not always rewarded to worthy inmates, thus putting society at risk for repeated crimes that often outweigh the benefits of parole, therefore, parole should be abolished and inmates should be made to complete their full sentences. Prison inmates are usually sentenced by the severity of their crimes, as well as their mental intention at the time of the act. For example: a person who commits murder intentionally expects to take the life of another in reckless disregard for human life, and knows that the act itself which he or she has decided to commit, will surely bring about death. However, in the case of manslaughter, which is also the taking of a human life, there is no actual intention to bring about death. The act that lead to someone’s death, is measured by the circumstances that made the person kill such as self-defense, or a crime of passion because the killer was provoked in such a way that a chain of events lead to violence which eventually resulted in peril. Because of the difference in how these crimes are carried out, inmates are sentenced differently; some are sentenced to life in prison, and others are sentenced to several years and will be eligible for parole after serving part of their sentence. In lieu of inmates completing their full sentences, parole tries to achieve releasing inmates early based on the idea that the inmate has been sufficiently punished, and should be given the opportunity to become a law abiding citizen, capable of functioning in our society with adequate supervision. Although parole attempts to carefully screen inmates prior to granting early release, their decisions often do not merit wise choices. As a social worker, I e... ...niors who brought us into this generation. We deserve to be protected as much as any other human race. Our tax dollars spent on housing inmates are a lot cheaper for us to pay when one considers the cost of irreparable pain and suffering, of a victim who falls prey to a parolee who had no intention of reversing his or her former lifestyle and recommitted their life to crime. One cannot put a price tag on scarred lives. It would be worth every penny to keep these criminals behind bars until they have completed their full sentences, if it meant even saving one innocent life, or sparing someone an unforgettable damaging experience. In conclusion, parole serves to benefit the inmate who is seeking his or her freedom, while society seldomly benefits from progress or efforts implemented by parolees in the community. We must understand that parole is a privilege, not a right. We must take into consideration that if almost half of the population that is released on parole returns to pris on; parole is not working and should be abolished. Law abiding citizens have earned their right to freedom, and criminals have earned their right to confinement, and should remain that way, as sentenced.

1015 Folsom Night :: essays research papers

There are many nightclubs in the city of San Francisco and throughout the Bay area. There is two different kind of nightclub. One is the high-class nightclub, which the cover charge is more expensive, tight security and the nightclub itself is more exclusive. The other one is the lower class club, which all people can enter and the security is not that tight. Nowadays, most nightclubs are the same. Nightclub used to be for people to meet their friends and having fun together but nowadays many people misuse nightclub as a place for using drug. I never like to go to nightclub because the place is very noisy, dark and lastly drugs are often involve in nightclub. It took me a few hours to decide which club to go. I am a person who likes to stay at home watching television, playing video games and surfing through the Internet. Well, it was very hard for me to go out, as my legs felt heavy to walk through the front door. After a long struggle, then I forced myself to go to a nightclub. My friend recommended me to go to 1015 Folsom nightclub because the songs are funkier. The club is located at Folsom street, downtown San Francisco. We arrived at 1015 Folsom around 11.45pm. Many people were still lining up to get into the discotheque. I didn't know why people like to go to such a dark and noisy place like that. Anyway, people who were there are mostly dressed up. Some of them looked interesting. My attention went to an old man about 50-60 years old man who were already dressed up and ready to rock his world. I wondered why would the old man go to a nightclub. May be he was lonely or may be he was just looking for fun and excitement. Well, I didn't really know. Ten minutes after lining up, I went inside the nightclub. From the door, I could hear the song and the beat of the bass so loud that my heart could feel it. Inside the nightclub, I saw people were dancing everywhere, on dancing floor, on their own seats, everywhere. They would dance and take a big gulp of their beer. Even the bartenders were dancing too, following the rhythm of the loud funky music. The rainbow rays of light moved through the club to make the mood even more exciting and funky.

Positive and Negative Reinforcement

Positive and Negative Reinforcement Reinforcement is an essential part in identifying and encouraging a certain behavior. In the most classic definition, positive reinforcement is a method of identifying to children which behaviors are acceptable and appropriate and which are not (Sigler, E. & Aamidor, S, 2005). Reinforcement is often given as praise for doing a certain task. As educators, saying â€Å"great job† or a simple word like â€Å"fantastic† are expressed towards students as praise. However, when a student is struggling and praise is given such as â€Å"you are doing so well†, the negative aspects of praise present themselves.The child is aware of the empty praise therefore it may work against the teacher if it is taken as a false praise. So, as educators, we must determine what reinforcements will work with each individual child through experimentation. Also, building a relationship with not just the child, but the parents and all those involved with t he child will be instrumental in developing the proper use of reinforcements and can be helpful in gaining knowledge of certain behaviors. The stronger reinforcements for most children are usually food, candy, or drinks.The durability and effectiveness of a reinforcer can usually be determined best by reinforcing the behavior intermittently or by providing a strong alternative which could interfere with the behavior in question (Ferster, C, 1961). Positive reinforcement is not just about the behaviors of the child but the reaction of the teacher and the adults to certain behaviors. Although a child may attempt to test the boundaries of one’s attention, positive attention does not make a child behave inappropriately (Sigler & Aamidor, 2005). The reinforcing comes from the teacher or adults actions and words.For example, Joshua is an eight-year-old autistic boy who begins to whine and cry every single time the teacher tries to get him to begin a task that he dislikes. Most of t he time Josh only wants to play on the computer, participate in gym, or eat. Each and every time Josh began to break down the staff usually asked him what he wanted or just gave in to what he wanted to do, not even trying to redirect him to the actual task at hand, which his classmates were doing. Joshua would get rewarded with chocolate, potato chips, and even some sympathy hugs from the staff.The behavior became more frequent and the result was the same. By now Joshua knew what he was going to get when he acted out, which was whatever he wanted. However, to change his behavior the staff began to ignore Josh and his outbursts. After a short time of whining and crying Josh threw himself on the floor but the staff still ignored the behavior. He then realized that he was not going to get the same results as he was getting by whining and crying when things didn’t go his way. The teacher then got his attention with another activity and Josh began to take part in the activity.A co uple weeks later, after the same lesson, Josh’s behavior was almost extinguished and slowly that behavior was no longer happening in the classroom. On the other hand, negative reinforcement is the removal of an aversive stimulus to increase a certain behavior. For example, when a student is distracted from his work due to loud music playing, however his work improves when the music is off, then the music being turned off is the reinforce. The difference between positive and negative can sometimes be difficult to acknowledge when there are several consequences and the need of the distinction is debated.The main purpose of giving punishments and rewards is to decrease or increase the behavior of the learner (Dad, Ali, Qadeer Janjua, Shazad, and Khan, 2010). Raul is a student with an emotional disorder and requires a great deal of support to help with his academic goals. Raul is extremely sensitive and becomes very overwhelmed when things don’t go his way. He whines, crie s, and loses control when he feels exhausted from taking instruction. Raul is very intelligent and needs to get verbal praise throughout his day to stay on task. His triggers are usually when he is asked to sit down within the circle during circle time.The behavior is him pulling away, crying, and hitting, trying to escape the actual activity. The maintaining consequence is that the adults let Raul leave the circle. There is not much fight with Raul because all those involved do not want the other students to become distracted. The first prevention is to give Raul some type of choice to coincide with circle time. A visual activity schedule could give him a more clear idea of what he should be doing and what the daily lessons and activities are. Raul will know exactly where he needs to be and what he needs to be doing at that particular time.Also, manipulatives and intermittent praise are other preventions that the teacher can use. Intermittent praise is praised use throughout the ac tivity but not regularly. This type of praise is given to become persistent. The new skills that can be developed are a part of the plan and may be implemented accordingly. Raul may have increased time of engagement, such as a longer duration of sitting within the circle. Raul will say â€Å"all done† when he has completed a task so praise can be given. This will help the adults notice him if he is not given the correct amount of attention.The responses to Raul for sitting longer will also be all positive praise toward Positive reinforcement is something that rewards the individual for an action taken. When students do or exhibit the correct or desired behaviors in school, then rewarding them for this action is what is known as positive reinforcement. There are many examples for these actions. Students that hand in homework on time may be given time near the end of class to put their books away and work on or do something they want to do within the rules of the school.Putting stickers on work well done so the student knows they did the right thing. Giving the class a free day or having fun activities planned for them to do instead of working on a certain day. Giving a weekly or reward to the student who has the best attendance or best behavior in the class. There are many ways to reward students or show them that by using good behavior, they can be rewarded for their actions and this will cause the student to want to do the right thing versus misbehaving in the classroom.References Dad, H. ; Ali, R. ; Qadeer Janjua, M. ; Shazad, S. ; Khan, M. (2010). Comparison of the Frequency and effectiveness of positive and negative reinforcement practices in schools. Contemporary Issues In Education Research. 3(1), 127-135. Ferster, C. B. (1961). Positive reinforcement and behavioral deficits of autistic children. Child Development. 32(2), 437. Sigler, E; Aamidor, S. (2005). From positive reinforcement to positive behaviors: an everyday guide for the practioner. Ea rly Childhood Education Journal. 32(4), 249-253.

Outline for the Good Earth Essay

One Man’s survival and triumph over the land and nature leads to a prosperous life. Thesis: Man’s triumph over the land and nature rewards with wealth and profit and respect from other. II. Introduction- How Wang Lang is connected to the earth and his strong relationship with it and how his good work ethics and moral judgments guide him on becoming one with his land. How Wang Lung tries to establish a connection with the land, the rewards and wealth from having a strong connection with the earth, and the respect from other while leading to a prosperous life. A. Establishing a connection- How Wang Lung attempts to have a strong connection with the earth. 1. Wang Lung starts connecting with the land a. Farms through own physical labor at first but O-Lan help his after they are together. b. He maintains his farm constantly through the changing seasons. 2. Wang Lung respect for nature guides him through his future success, How the nourishing power of the land comforts Wang Lung. b. The Earth producing for Wang Lung for his hard work and dedication B. Disasters for the land- How the nature damages Wang Lung connection with the Earth 1. Wang Lung and his family trying to survive against the elements of nature a. Wang Lung tries to survive from the famine that has struck the village because of the drought and is forced to move away from his land for a while. b. The flood affects Wang Lungs crops but because of his success from farming he is unaffected but becomes severed from his connection with the Earth. Wang Lung is forced to sever his connection with the earth because of nature a. When the famine struck Wang Lung is forced to move away from his land severing his connection and losing his strength to stay upon the land. b. Almost coming to the decision upon selling his daughter to return to the land corrupts Wang Lung moral judgments. C. Triumph over nature and the land- How Wang Lung connection with the land is restored and the wealth he is rewarded with. 1. Wang Lungs connection with the Earth is stronger than before. When returning from the city with money him able to purchase property and profit from his expanding land he has gained because of the Earth providing him with more resources. b. Through hard work he has become more profitable and wealthier than before and is able to provide for his family. 2. Wang Lung leading a prosperous lifestyle with the current wealth he has gained. a. He is able to become wealthier and afford many lavished items in his household and lead a good lavished life while he is now old. b. He becomes well respected within his village and is looked upon as one of the great family’s to the villagers.