Nurses' Use of Water-Filled Gloves in Preventing Heel Pressure Essay

Nurses' Use of Water-Filled Gloves in Preventing Heel Pressure Ulcer in the University college hospital, Ibadan, Nigeria - Essay Example The interpretations considers the limitations cited by the researcher. When pick samples data organization was considered. â€Å"†¦ two units and who met the inclusion criteria constitute the study participants† (Polit & Beck, 2014, p. 473) The evidence given was the numeric data collected from the pick sample. The participant in the sample provided a rigid support for the results.† †¦have never used it in spite of its availability and common use as submitted bya nurse in one of the wards† (Adejumo &Ingwu, 2010 P. 474) The findings from the study were explained in light of other previous studies. â€Å"This is in support of Watson (19), who maintained that unless a nurse learns from experience, the learning is not good (Adejumo &Ingwu, 2010 p.476) In some instances, the researchers made some indefensible spontaneous inferences. â€Å"†¦ which does not make it scientific and as such lacks basis for clinical decision making.† (Adejumo &Ingwu, 2010 p.476) The rationales for rejecting alternatives were defective in that research involves search of information from a variety of sources.† In hypothesis testing, researchers assume that the null hypothesis is true and then gather evidence to disprove it.† (Polit & Beck, 2014, P. 230) The interpretation accounted for precision of the results. â€Å"In our study, the probability of obtaining a value of 71.0% female by chance alone was less than 1 in 10,000.† (Polit & Beck, 2014, p.230) The researchers pointed out the differences between practical and statistical significance. â€Å"†¦they are not well-suited for testing actual research hypotheses about the absence of relationships between variables or about equivalence between groups.† (Polit & Beck, 2014, P. 258) Some unwarranted generalization was evident in the results of the research. â€Å"Although it is difficult to depend on the rating of nurses based simply on their perception, success or failure of WFGs in prevention of heel PUs is difficult to

Theories of Addiction Explanations for Continuing Drug Use and Relapse Essay Example for Free

Theories of Addiction Explanations for Continuing Drug Use and Relapse Essay Theories of addiction, many have been proposed and a variety of preclinical models have been constructed. several theories were utilized in this study to better understand the basis of addiction. The first theory, negative reinforcement, suggests that the continued use of the psychoactive substance is to avoid withdrawal dysphoria. The next theory subject to research during this study was positive reinforcement. The positive reinforcement theory of addiction suggests the subject continues use of the psychoactive substance simply because they enjoy it. These theories, positive reinforcement the more familiar of the preclinical models of addiction, stem from the associative learning theory. Either of these preclinical models are a perfect example of operant conditioning. Both subjects have associated their use of the psychoactive substance with consequences, reinforcing the behavior. Operant conditioning is the easiest form of associative learning and the hardest to correct once behavior is learned in this manner. There have been several studies done to understand operant conditioning. The most prominent was the operant chamber, a Skinner box. It was built in the mid sixties by B. F. Skinner and brought modern behaviorism to the forefront of psychology. Though a very controversial study much was learned in behavior control and was called the law of effect, stating that rewarding behavior is likely to recur. Another crucial model in understanding addiction is stimulus response learning. This model suggests, unlike that of associative learning where the response follows the stimulus, the stimulus itself creates a habitual response. This this occurs through classical conditioning and is a conditioned response. This conditioned response is developed through conditioned reinforcement. When the subject comes in to contact with paraphernalia, like the light in the skinner box, they know they are going to receive their primary reinforcer. This can easier be illustrated with Pavlovs studies on classical conditioning. Pavlov began to notice that dogs salivating whenever he w ould present the with a bowl of food. This is an example of an unconditioned stimulus eliciting an unconditioned response. When you introduce a neutral stimulus with an unconditioned stimulus. In this case the paraphernalia, you receive the unconditioned response. Eventually, if this is repeated over time the once neutral stimulus elicits the same response as the unconditioned stimulus. The once unconditioned response is now a conditioned response and can be controlled with exposure to the conditioned stimulus. When the subject is exposed to the paraphernalia the body begins adjusting for the use of the psychoactive substance and causes the cravings associated with addiction. The next model researched in the study was incentive salience. This is a motivational attribute given by the brain to reward predicting stimuli, causing the craving for the psychoactive substance. For example, if the subjects addictive behavior is extinguished and is then exposed to an illustration once associated with the stimulus, the craving can return. Cravings can also return through spontaneous recovery. This is when the subjects addictive behavior is extinguish and, without stimuli exposure, the subjects craving for the substance returns briefly. This is believed to be cause of relapse in some subjects battling this disorder. The final model to be discussed is the inhibitory control dysfunction model. Inhibitory control consists of neural impulses that act to dampen or stop a specific activity. The area of the brain that this function occurs is in\the pre-frontal cortex. This area of the brain is in control of personality, decision making, and other functions. If damage or a dysfunction is present in this area of the brain it could alter the subjects personality and decision making abilities. Other symptoms of this is impulsiveness and altered judgment. As a result if the subject has a dysfunction in this area they are more likely to begin, continue, and possibly relapse use of a psychoactive substance. The study was comprised of seventy-three non-treatment seeking Methamphetamine u sers both men and women. They were given a survey with questions of self perceived reasons why a methamphetamine user would continue use or relapse. They found that fifty-six percent of the participants use psychoactive substances due to positive reinforcement, forty-four percent would relapse for the same. This theory was rated the highest next was inhibitory control dysfunction at twenty- seven percent, stimulus response learning at twenty-five percent, negative reinforcement at twenty- three percent, and incentive salience at nineteen percent. Most of the participants that rated positive reinforcement high also had correlations in there answers. They rated incentive salience, stimulus response learning and inhibitory control dysfunction. This suggests that other concepts of theories of addiction are needed for a better understanding of addiction. This study also shows that not all methamphetamine users are alike, treatment should be further focused in subtypes. If treatment were focused and developed in subtypes it may be more effective. By issuing the survey to non-treatment seeking methamphetamine users they were able to identify possible patient subtypes. Thus bringing the treatment to the subject instead of the disorder.

Cause And Effects Of Soil Erosion

Cause And Effects Of Soil Erosion The Latin word erodere,meaning to gnaw away is the origin of the word erosion (Roose, 1996). Soil Erosion is the physical removal of topsoil by various agents, including falling raindrops, water flowing over the soil profile and gravitational pull (Lal 1990). The Soil Science Society of America defines erosion as the wearing away of the land surface by running water, wind, ice or other geological agents, including such processes as gravitational creep (SCSA, 1982). Physical erosion involves the detachment and transportation of insoluble soil particles (sand, silt and organic matter). Removal of soluble material as dissolved substances is called chemical erosion and this maybe caused by surface runoff or subsurface flow where the water moves from one layer to another within the soil profile (Lal 1990). According to ASCE, 1975, the physical processes in soil erosion include detachment of soil particles, their transportation and subsequent deposition of soil sediments downslope by raindrop impact and runoff over the soil surface. Rainfall is the most important detaching agent (Morgan and Davidson 1986; Lal, 1990) followed by overland flow in entraining soil particles (Lal 1990). The process of soil erosion occurs in three main steps, detachment of soil particles, transportation and deposition of soil particles downslope by raindrop impact and runoff over the soil surface (ASCE 1975; Morgan and Davidson, 1986, Lal 1990) followed by overland flow in entraining soil particles (Lal, 1990). Soil erosion reduces soil productivity by physical loss of topsoil, reduction in rooting depth and loss of water. In contrast soil, soil depletion means loss or decline of soil fertility due to crop removal or removal of nutrients by eluviations from water passing through the soil profile (Lal, 1990). Sedimentation however, causes off site effects like degradation of basins, accumulation of silts in water reservoirs and burial of low-lying productive areas and other problems (Lal, 1990). Sediments is the main cause of pollution and eutrophication (Lal, 1990). According to Lal 1990, soil degradation may be caused by accelerated soil erosion, depletion through intensive land use , deterioration in soil structure, changes in soil pH, leaching, salt accumulation, build up of toxic elelments such as aluminum or zinc, excessive inundation leading to reduced soil conditions and poor aeration. Soil Erosion is the most serious and least reversible form of land degradation (Lal, 1977; El-Swaify, Dangler and Amstrong, 1982). Soil erosion and soil loss , according to Lal (1990) have adverse effects on agriculture because they deplete the soils productivity and diminish the resourse base. 2.2 Soil Erosion Process Geologic erosion can be caused by a number of natural agents including rainfall, flowing water and ice, wind and the the mass movement of soil bodies under the action of gravity which cause the loosened or dissolved earthy and rock materials to be removed from a place and eventually deposited to a new location (Lal,1990; Morgan and Davidson, 1986). The Soil Science Society of America (SCSA, 1982) described geologic erosion as the normal or natural erosion caused by geologic processes acting over long periods and resulting in the wearing away of mountains, the building up of flood plains, coastal plains. Etc. The slow and constructive natural soil erosion process has been significantly accelerated by human activities of poor farming practices, overgrazing, ground clearing for construction, logging and mining (Lo, 1990). Accelerated erosion not only affects the soil but also the environment and is the primary cause of soil degradation (Lal, 1990). Agriculture has been identified as th e primary cause of accelerated soil erosion (Pimentel, 1976). 2.3 Soil Characteristics in the Tropics Extremes of climate and wide variety of parent materials cause great contrast of soil properties in the tropics from soils in other temperate regions. In the tropics soils are highly variable and diverse like the vegetation (Sanchez and Buoi, 1975; Van Wambeke, 1992). The main soil types are alfisols, oxisols, ultisols and inceptisols (El-Swaify, 1990). Tropical soils low in weatherable minerals and basic cations (sodium, calcium, magnesium, and potassium) resulted from continuous weathering of parent materials (Lo, 1990). The ability of these soils to keep plant nutrients is largely dependent on the humus content found in plant biomass and the organic matter (Rose,1993). The inactivity of soil mineral constituents (kaolin and sesquioxides) in these soils, causes deficiency in crop nutrients, lowers the capacity to retain basic cations, limits active relationship with organic matter and excessively immobilizes phosphates and related anions, a condition which are highly toxic to plant roots (Lo, 1990). Crop production in tropical soils are constrained by primarily aluminum- derived soil acidity and infertility but generally their physical properties are favourable (El-Swaify, 1990). Tropic soils have moderate to high permeability under natural conditions, but susceptible to slaking and development of impermeable crust upon action of raindrops and as a result runoff increases with continuous cultivation (Lal, 1982). This crusting cause insignificant reduction of filtration rate, increasing water runoff which leads to acceleration of soil erosion (Falayl and Lal, 1979). It is important to note however that heavy and intense rains cause severe erosion in the tropics (Morgan, 1974; Wilkinson 1975; Amezquita and Forsythe, 1975; Lal 1976; Aina, Lal and Taylor, 1977; Bois, 1978; Sheng 1982). 2.4 Soil Erosion on Steep Slope According to Lal 1990, Steeplands refer to lands with a slope gradient greater than 20%. It is important to note however that flat undulating lands have a great potential for crop production and agricultural development. Due to the possibility of soil erosion and the problem of mechanization, the steep areas are considered marginal for agriculture production (Lal, 1990). The difficult topography in steepland agriculture restricts mechanizations of operations thus, reducing all agricultural activities (land preparation, cultivation and harvesting), limiting the farmer in scale and efficiency. Inputs such as fertilizer and pesticides have to be carried manually by the farmer. As a resulted they are used scarcely. Observably any increase in the use of these agricultural inputs will result in decline in he farmers profits from the generally lower agricultural field (Benvenuti, 1988). For all these reasons steepland farmers tend to concentrate in high value crop production of limited scale (Ahmad, 1987; Ahmad 1990). It is important to note however that farmers prefer steepslopes due to cultural hand cultivation, planting and harvesting can be done in an upright fashion (Williams and Walter, 1988). Futher more subsistence farmers are found on steep slopes because of more favourable environmental conditions such as lower temperatures, reduced diseases and h igher reliability of rainfall. (Hurni, 1988). In the tropics, removal of forest vegetation causes excessive leaching and accelerated soil nutrient loss. Being highly weathered soil types , their contained minerals generally have poor ability to retain sorbed nutrients against leaching. Clay soils with high residualmiron contents are considered superior in resistance to runoff caused soil erosion; thus, soils emanated from basic igneous rocks and red soils developed from calcareous rocks are strongly aggregated due to the cementing property of iron oxides, hence, soil erosion is expected to be less than for most other soils. Also soils developed from fragmentary volcanic materials with andic properties are resistant to soil erosion (Sheng, 1986; Ahmad, 1987; Ahmad, 1990; Lal, 1990). Soils formed from shales, schists, phyillites and sandstones are considered highly erodible. Soils produced from these rocks are high in both sand or silt fraction, and clay minerals and iron oxides are generally insufficient as cementing agents for a stable-structured soil. These parent materials are generally rich in muscovite occurring in all soil particle-size fractions. Micah-rich soils are weak-structured, and thus raindrops can easily dislodged the weak aggregates, while the clay fraction dispersed in water. The resulting mica flakes settling on their flat axes in the water film on the soil surface causes soil crusting. The formation of soil crusts further restricts water entry into the soil (Ahmad and Robin, 1971; Sumner, 1995), resulting to disposal of a much greater volume of runoff water, a condition which leads to further disintegration of soil aggregates and transport of colloidal soil material (Ahmad, 1987; Ahmad 1990). Soil crust restricts gaseous exchange leading to anaerobic soil conditions, denitrification, toxic effects due to ethylene production, and mechanical impedance to seedling emergence (Ahmad 1987; Ahmad, 1990). Steep slope cultivation can cause certain instability in the ecological system with both onsite and offsite detrimental impacts (El-Swaify, Garnier and Lo, 1987). Soil, climate, land use and farming systems affect the extent and the degree of severity of soil erosion. However, regardless of soil and climatic conditions, intensively used steeplands in densely populated regions experience severe soil erosion problem. Land use influences the degree of severity of soil erosion on steeplands. Uncontrollable grazing or over grazing, exensive and abusive cultivation, diversified cropping are responsible for severe soil erosion in unprotected arable lands (Roose, 1988; Liao et al 1988). Ahmad (1987;1990) reportd soil loss of approximately 120 t0 180 tonnes per hectare in Tobago Trinidad. In Australia, annual soil loss of 200 t/ha to 328 t/ha has ben reported from sloping sugar cane plantations in central and north Queensland (Sallaway, 1979; Mathews and Makepeace 1981). There are two types of soil erosion associated with the Caribbean region, land slipping and gullying. Land slipping is a manifestation of mass movement associated with steepland agriculture and the severity being strongly influenced by the parent materials. Land clearing (example deforestation) and crop production can influence land slipping particularly in the early portion of the wet season when the cleared soil wets faster due to saturation of the soil above rock. Serious dislocations, crop loss and destruction of any mechanical anti erosion devices can result from this form of mass movements. Due to drastic changes in hydrological conditions experienced by land naturally prone already to slipping and cleared for agriculture for the first time land slippage would be of common experience (Ahmad 1987; Ahmad 1990). Gullying is another common form of soil erosion that occurs on steep land bcause of the terrain involved. This is more common on sandy soils, volcanic soils and vertisols, which are all porous materials. Soils easily attain saturated conditions upon the rapid entry of water, consequently breaking the material and ultimately, leading to the formation of gullies. Agricultural activities enables this soil erosion in steeplands by allowing rapid soil wetting upon the start of the wet season. Farming activities though unsuitably oriented field boundaries, foot tracks and the lack of provision for disposal of surface water are some main causes of gullying, even on soils not prone to this tpe of steepland soil erosion (Ahmad 1987;Ahmad 1990). Since steeplands are traditionally considered marginal for agricultural crop production, most research on soil erosion and soil conservation has been done on either flat land or rolling land with a maximum slope of about 20%'(Lal, 1988). 2.5 Factors Affecting Soil Erosion The causes of soil erosion have been intensively discussed during the past 40 years. Soil erosion is a natural process that is enhanced by human activity (Richter, 1998) and occurs in all landscapes and under different land uses. In addition to human activities, soil erosion processes are also caused by morphometric characteristics of the land surface, the erosive forces of rainfall and the erodibility of soils and soil surfaces. When rainwater reaches the soil surface it will either enter the soil or run off. Runoff occurs when the rainfall intensity exceeds the infiltration capacity of the soil. Water erosion is the result of the dispersion action of rain drops, the transporting power of water and also the vulnerability of the soil to dispersion and movement (Baver and Gardner, 1972). The effects of soil erosion is also classified: definition of gullies and explanation of gully development is given by Morgan (1996), as well as Hudson (1995) who additionally focuses on individual cases of the development of gullies. Toy et al (2002) give detailed definitions of soil erosion features and processes such as sheet erosion and inter-rill erosion, rill erosion, as well as ephemeral and permanent gully erosion. Rill erodibility depends both directly and indirectly on soil properties such as bulk density, organic carbon and clay content, clay mineralogy, cations in the exchange complex, soil pH and experimental conditions such as moisture content, aging of prewetted soil and quality of eroding water (Rapp,1998). Govers (1990) found that runoff erosion resisitance of a loamy material was extremely sensitive to variation in the initial moisture content and to a lesser extent to changes in bulk density. The process of water erosion can be separated into two components, rill and interrill erosion (Young and Onstad, 1978). Interrill erosion (sheet erosion) is mainly caused by raindrop impact and removes soil in a thin almost imperceptible layer (Foster, 1989). In interril erosion the flow of water is generally unconfined, except between soil clods and covers much of the soil surface. As the velocity of flow increases the water incises into the soil and rills forms (Evans,1980). Rill erosion begins when the eroding capacity of the flow at some point exceeds the ability of the soil particles to resistant detachment by flow (Meyer cited by Rapp, 1998). Soil is detached by headcut advance from knickpoints (De Ploey, 1989; Bryan, 1990), rill slide sloughing and hydraulic shear stress (Foster cited by Rapp, 1998) as well as by slumping by undercutting of side walls and scour hole formation (Van Liew and Saxton, 1983). These processes are usually combined into a detachment prediction equation as a function of average shear stress (Foster cited by Rapp, 1998). When the rills develop in the landscape, a three to five fold increase in the soil loss commonly occurs (Moss, Green and Hutka 1982 and Meyer and Harmon 1984). 2.5.1 Vegetative Factors The effects of vegetation can be classified into three catergories: The interception of raindrops by the canopy (DHuyvetter, 1985). Two effects are associated with this. Firstly, part of the intercepted water will evaporate from the leaves and stems and thus reduce runoff. Secondly, when raindrops strike the vegetation, the energy of the drops is dissipated and there is no direct impact on the soil surface. The interception percentage depends on the type of crop, the growth stage and the number of plants per unit area. A well distributed, close growing surface vegetative cover will slow down the rate at which water flows down the slope and will also reduce concentration of water (DHuyvetter, 1985). As a result, it will decrease the erosive action of running water. There is also the effect of roots and biological activity on the formation of stable aggregrates, which results in a stable soil structure and increased infiltration that reduces runoff and decreases erosion (DHuyvetter, 1985). Increased permeability also reduces erosion as a result of in increased water percolation due to better drainage. Stables aggregrates in the topsoil also counteract crusting. 2.5.2 Rainfall Factors Raindrop size, shape, duration of a storm and wind speed interactions controls the erosive power of rainfall (DHuyvetter, 1985). The erosivity of rainfall is expressed in terms of kinetic energy and is affected by various factors. According to Wischmeier and Smith (1965), the intensity of rainfall is closely related tot e kinetic energy, according to the regression equation E = 1.213 + 0.890 log I Where E = the kinetic energy (kg.m/m2.mm) I = rainfall intensity (mm/h) Raindrop size, distribution and shape all influence the energy momentum of a rainstorm. Laws and Parson (1943) reported an increase in median drop size with increase in rain intensity. The relationship between mean drop size (D50) and rainfall is given by: D50:2.23 I 0.182 (inch per hour). The median size of rain drops increases with low and medium intensity fall, but declines slightly for high intensity rainfall (Gerrard, 1981). The kinetic energy of an rainfall event is also related to the velocity of the raindrops at the time of impact with the soil (DHuyvetter, 1985). The distance through which the rain drop must fall to maintain terminal velocity is a function of drop size. The kinetic energy of a rainstorm is related to the terminal velocity according to the equation: Ek = IV2/2 Where Ek = energy of the rain storm I = Intensity V= Velocity of raindrop before impact Ellison (1945) developed an equation showing that the relationship between the soil detached, terminal velocity, drop diameter and rainfall intensity: E = KV4.33 d1.07 I0.63 Where E = relative amount of soil detached K = soil constant V = velocity of raindrops (ft/sec) d = diameter of raindrops (mm) I = rainfall intensity 2.5.2.1 Effect of rainfall intensity on runoff and soil loss According to Morgan (1995), soil loss is closely related to rainfall partly through the detaching power of raindrops striking the soil surface and the contribution of rain to runoff. If rainfall intensity is less than the infiltration capacity of the soil, no surface runoff occurs and the infiltration rate would equal the rainfall intensity (Horton, 1945) as sited by Morgan (1995). If the rainfall intensity exceeds the infiltration capacity, the infiltration rate equals the infiltration capacity and the excess rainfall forms surface runoff. According to Morgan (1995), when the soil is unsaturated, the soil matric potential is negative and water is held in the capillaries due to matrics suction. For this reason, under saturated conditions sands may produce runoff very quickly although their infiltration capacity is not exceeded by the rainfall intensity. Intensity partially controls hydraulic conductivity, increasing the rainfall intensity may cause conductivity to rise so that although runoff may have formed rapidly at relatively low rainfall intensity, higher rainfall intensities do not always produce greater runoff (Morgan, 1995). This mechanism explains the reason why infiltration rates sometimes increase with rainfall intensities (Nassif and Wilson, 1975). 2.5.3 Soil Factors According to Baver et al, (1972), the effect of soil properties on water erosion can be in two ways : Firstly, certain properties determine the rate at which rainfall enters the soil. Secondly, some properties affect the resistance of the soil against dispersion and erosion during rainfall and runoff. The particle size distribution is an important soil property with regards to erodibility. Generally it is found that erodible soils have a low clay content (DHuyvetter, 1985). Soils with more than 35% clay are often regarded as being cohesive and having stable aggregates which are resistant to dispersion by raindrops (Evans, 1980). Evans also stated that sands and coarse loamy sands are not easily eroded by water due to its high infiltration rate. In contrast soils with a high silt or fine sand fraction are very erodible. Erodibility of soil increases with the proportion of aggregates less than 0.5mm (Bryan, 1974). Factors which contribute to aggregate stability include organic matter content, root secretions, mucilaginous gels formed by break down of organic matter, the binding of particles by sesquioxides and the presence of a high Ca concentration on the exchange sites of the colloids instead of a high sodium content (DHuyvetter, 1985). The depth of erosion is determined by the soil profile (Evans, 1980). According to Evans soil horizons below the A horizon or plough layer are often more compact and less erodible. The texture and chemical composition of the sub surface horizon can also have an adverse effect. Normally deep gullies can be cut if the parent material is unconsolidated. If resistant bedrock is near the surface only rills will develop. Soil rich in surface stones are less susceptible to erosion (Lamb, 1950 and Evans, 1980). Stones protect the soil against erosion and also increase the infiltration of the flowing water into the soil. The antecedent soil moisture and the surface roughness are both regarded by Evans (1980) as important soil factors affecting erosion. The ability of a soil to accept rainfall depends on the moisture content at the time of the rainfall event. 2.5.3.1 Factors affecting aggregate stability Soil structure is determined by the shape and size distribution of aggregates. Aggregrate size and strengthe determine the physical properties of a soil and its susceptibility to breakdown due to water forces. Their stability will have a decisive effect on soil physical properties (Lynch and Bragg, 1985). The main binding materials giving stable aggregates in air dry state are the glueing agents in organic matter (Chaney and Swift, 1984; Tisdale and Oades, 1982) and sesquioxides (Goldberg and Glaubic, 1987). 2.5.3.1.1 Aluminium and Iron Oxides The soil used by Kemper and Koch (1966) contained relatively little free iron, although it did contribute to aggregrate stability. Their data show a sharp increase of free iron from 1 to 3%. Goldberg and Glaubic (1987) concluded that Al-oxides were more effective than Fe-oxides in stabilizing soil structure. Al-oxides have a greater proportion of sub-micrometer size particles in a sheet form as opposed to the spherical form of Fe-particles. Shainberg, Singer and Janitzky (1987) compared the effect of aluminium and iron oxides on the hydraulic conductivity of a sandy soil. 2.5.3.1.2 Organic Matter Organic matter can bind soil particles together into stable soil aggregates. The stabilizing effect of organic matter is well documented. Little detailed information is available on the organic matter content required to sufficiently strengthen aggregates with ESP values greater than 5 or 7, and containing illite or montmorrillionite, so as to prevent their dispersion in water (Smith, 1990). High humus content makes the soil less susceptible to the unfavourable influence of sodium (Van den Berg, De Boer, Van der Malen, Verhoeven, Westerhof and Zuur, 1953). Kemper and Koch (1966) also found that aggregate stability increased with an increase in the organic matter content of soils. A maximum increase of aggregate stability was found with up to 2% organic matter, after which aggregate stability increased very little with further increases in organic matter content. 2.5.3 Slope Factors Slope characteristics are important in determining the amount of runoff and erosion ( DHuyvetter, 1985). As slope gradient increases, runoff and erosion usually increases (Stern, 1990). At low slopes due to the low overland flow velocities, detachment of soil particles from the soil surface into the water layer is due to detachment alone (Stern, 1990). Additionally, at low slope gradients, particles are splashed into the air in random directions unlike the case with steeply sloping land where down slope splash occurs (Watson and Laflen, 1985). As slope gradient increases, the ability for surface runoff to entrain and transport sediments increases rapidly until the entrainment by the surface runoff becomes dominant contributing to sediment transport (Stern, 1990). Foster , Meyer and Onstad (1976) presented a conceptual model that showed that at lower slopes, interill transport determined erosion, while at steeper slopes, raindrop detachment determined it. Th uniform bed characteristics of sheet flow transport tend to be replaced by channels because of instability and turbulent flow effects (Moss, Green and Hutka, 1982). There are many empirical relationships relating soil transport by surface wash to slope length and slope gradient. Zingg (1940) showed that erosion varied according to the equation: S = X1.6 tanB1.4 Where S = soil transport cm/yr X = slope length (m) B = slope gradient (%) Studies conducted by Gerrard (1981), showed that plane and convex slopes did not differ significantly in the amount of soil lost by surface runoff, but concave slopes were less eroded. Some researchers such as Zingg (1940) and Mc Cool et al (1987) indicated that soil erosion increases exponentially with increase in slope gradient. The relationship is indicated after Zing (1940) by: E = aSb where E is the soil erosion, S is the slope gradient (%) and a and b are empirical constants. The value of b ranges from 1.35 to 2.0. The other relationship between erosion and slope gradient for inter-rill erosion is given by Mc Cool et al (1987) E = a sin b Q+C Q is the slope angle in degrees A,b and C are empirical constants. However, even if the effect of slope gradient on erosion is well recognized, several studies indicate that the power relationship between slope gradient and soil loss over predicts interrill erosion rate by as much as two or more times (Torri, 1996;Fox and Bryan, 1999), and the relationship is better described as linear. 2.8 Soil Erosion Impacts 2.8.1 Soil Physical Properties Progressive soil erosion increases the magnitude of soil related constraints for crop production. These constraints can be physical, chemical and biological. The important physical constraints caused by erosion are reduced rooting depth, loss of soil water storing capacity (Schertz et al 1984; Sertsu, 2000), crusting and soil compaction and hardening of plinthite (Lal, 1988). Erosion also results in the loss of clay colloids due to preferential removal of fine particles from the soil surface (Fullen and Brandsma, 1995). The loss of clay influences soil tilth and consistency. Exposed subsoil is often of massive structure and harder consistency than the aggregated surface soil (Lal, 1988). Development of rills and gullies may change the micro-relief that may make use of farming machinery difficult. Another effect of erosion is that the manangement and timing of farm operations. 2.8.2 Soil Chemical Properties Soil erosion reduces the fertility status of soils (Morgan, 1986; Williams et al., 1990). Soil chemical constraints and nutritional problems related to soil erosion include low CEC, low plant nutrients (NPK) and trace elements (Lal, 1988; Fullen and Brandsma, 1995). Massy et al (1953) reported an average loss of 192 kg of organic matter, 10.6 kg of N and 1.8kg per ha on a Winsconsin soils with 11% slope. Sharpley and Smith (1990) reported that the mean annual loss of total P in runoff from P fertilized watersheds is equivalent to an average of 15%, 12% and 32% of the annual fertilizer P applied to wheat, mixed crop grass and peanut sorghum rotation practices respectively. Researchers (Massy et al 1953; Lal, 1975) have also reported extensive loss of N in eroded sediments. 2.8.3 Productivity Quantifying the effects on crop yields is a difficult task. It involves the evaluation of interactions between soil properties, crop characteristics and climate. The effects are also cumulative and not observed until long after accelerated erosion begins. The degree of soil erosions effects on crop yield depends on soil profile characteristics and management systems. It is difficult to establish a direct relationship between rates of soil erosion and erosion induced soil degradation on the one hand and crop yield on the other (Lal, 1988). It is well known that soil erosion can reduce crop yields through loss of nutrients, structural degradation and reduce of depth and water holding capacity (Timilin et al, 1986; Lal,1988). Loss of production in eroded soil further degrades its productivity which in turn accelerates soil erosion. The cumulative effect observed over a long period of time may lead to irreversible loss of productivity in shallow soils with hardened plinthite or in soils that respond to expensive management and additional inputs (Lal,1988). 2.8.4 Off Site Effects of Soil Erosion. Effects of erosion include siltation of rivers, crop failure at low lying areas due to flooding, pollution of waterbodies due to the various chemicals brought by the runoff from different areas. Several studies reported the significance of the off site effects of soil erosion on land degradation (eg. Wall and ven Den,1987; Lo, 1990; Robertson and Colletti, 1994; Petkovic et al, 1999) Rainwater washes away materials that originate from fertilizers and various biocides (fungicides, insecticides, herbicides and pesticides) which are applied in large concentrations. They reappear in greatr quantities in the hydrosphere polluting and contaminating the water environment (Zachar,1982;Withers, and Lord, 2002; Verstraeten and Poesen, 2002). Chemical pollution of water mainly by organic matter from farm fields causes rapid eutrophication in waterways (Zachar, 1982;Zakova et al, 1993; Lijklema, 1995). 2.8.5 Soil Erosion Models Modelling soil erosion is the process of mathematically describing soil particle detachment, transport and deposition on land surfaces (Nearing et al, 1994). Erosion models are used as predictive tools for assessing soil loss and project planning. They can also be used for understanding erosion processes and their impacts (Nearing et al 1994). There are three main types of models, empirical or statistical models, conceptual models and physically based models (Morgan 1995, Nearing et al 1994, Merritt et al 2003). It is important to note however that there is no sharp difference among them. 2.8.5.1 Physically Based Models These models are based on solving fundamental physical equations describing stream flow and sediment and associated nutrient generations in a specific catchment (Merritt et al ., 2003). They are developed to predict the spatial distribution of runoff and sediment over land surfaces during individual storms in addition to total runoff and soil loss (Morgan, 1995). Physically based models are also called process based models (Morgan, 1995) as they rely on empirical equations to determine erosion processes. These models use a particular differential equation known as the continuity equation which is a statement of conservation of matter as it moves through space over time. The common physically based models used in water quality studies and erosion include : The Areal Non-Point Source Watershed Environment Response Simulation (ANSWERS) (Beasley et al., 1980), Chemical Runoff and Erosion from Agricultural Management Systems (CREAMS) (Knisel, 1980), Griffith University Erosion System Temp late (GUEST) (Misra and Rose, 1996), European Soil Erosion Model (EUROSEM) (Morgan, 1998), Productivity, Erosion and Runoff, Functions to Evaluate Conservation Techniques (PERFECT) (Littleboy et al., 1992) and Water Erosion Prediction Project (WEPP) (Laflen et al., 1991). 2.8.5.2 Empirical Mode

Literary Critique of Langston Hughes Essay -- essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  Langston Hughes’s writing showcases a variety of themes and moods, and his distinguished career led his biographer, Arnold Rampersad, to describe him as â€Å"perhaps the most representative black American writer.† Many of his poems illustrate his role as a spokesman for African American society and the working poor. In others, he relates his ideas on the importance of heritage and the past. Hughes accomplishes this with a straightforward, easily understandable writing style that clearly conveys his thoughts and opinions, although he has frequently been criticized for the slightly negative tone to his works.   Ã‚  Ã‚  Ã‚  Ã‚  One of the most predominate themes seen throughout Hughes’s poetry is that of discrimination. Hughes was a leader and spokesman for all underrepresented and mistreated societies, and he frequently questioned and criticized the established beliefs of the majority. He was especially outspoken for African Americans and the working poor. Hughes’s poem â€Å"Ballad of the Landlord† addresses the issue of prejudice in the sense of both race and social class. The lines â€Å"My roof has sprung a leak/ Don’t you ‘member I told you about it/ Way last week?† indicate both the speaking tenant’s predicament and the landlord’s disregard for an individual he obviously views as inferior. Upon confronting his landlord about the issue, the tenant is immediately arrested and tossed in jail. With the lines â€Å"Man threatens landlord/ Tenant held no...

Chicago Hope :: essays research papers

Chicago Hope, David E. Kelly’s infamous doctor-drama, premiered on September 18, 1994. Six years later, the show was canceled after its final season’s finale, which aired on May 4, 2000. Even though â€Å"Hope† couldn’t beat its direct competitor ER in the ratings race, the show still had a lot of good things going for it. Chicago Hope was nominated for a myriad of highly prestigious awards during its run. Many of these awards were lost to ER and other dramas but leading-lady Christina Lahti did receive both an Emmy and a Golden Globe for her performances on the show. Critic Mark Harris, even when as far as saying, â€Å"Lahti is, no question, the best dramatic actress in prime time.† (Entertainment Weekly, Oct. 4, 1996 p.51) Also, Hector Elizondo received an Emmy for his supporting role and people involved in off screen production won multiple awards. Chicago Hope was loved by critics even when being directly compared to ER. Chicago Hope was basically CBS’s answer to ER; a drama about doctors, taking place in a teaching hospital in Chicago, that aired on Thursdays at ten. The cast was constantly changing due to the constant ratings battle CBS was waging against NBC. Behind the scenes, CBS put its money on Executive Producer/Writer David E. Kelly who, at the time, was just coming off a successful run with Picket Fences; while NBC also went with a big name Producer/Writer/Novelist in Michael Crichton. Also, â€Å"Hope† used numerous directors and guest directors over the course of its six-year run, keeping the show fresh. Aside from the battle with ER and the constantly changing staff, this show definitely met or exceeded all of the requirements for a â€Å"quality TV† series outlined by Professor Robert J. Thompson in his book Television’s Second Golden Age. Chicago Hope was not your everyday TV escape. It was a show that made the viewer actually think about what was going on in both the show and the real world. It brought up issues that actually affected the lives of the people watching. It dealt with controversial issues like death, birth control, and AIDS. In the words of critic Ken Tucker, â€Å"†¦in a fall season with little quality [this is a] solid drama.† (Entertainment Weekly, Sept. 23, 1994 p. 52) Furthermore, â€Å"Hope† was the brainchild of Producer David E. Kelly, which, before the premiere even aired, meant that it was of high quality.

A World Of Intoxification :: essays research papers fc

A world of intoxification Screams pierced the midnight air and students ran wildly about the campus. Police cars whizzed by with their sirens blaring in the night. Glass was being broken and girls were being defiled. Confusion was all around and no one could stop it. This is an average night at any given university in America. The similarities between a horror story and a story about a college party are too many. At an average college party where alcohol is being served there is the possibility of fights, rape, death, destruction, and jail time. The common opinion in America is that all of these things are bad. So why do college students continue to engage in these activities? There are three reasons. First, if students have not been exposed to alcohol or drugs previously, when they get into that kind of environment, they will experiment. Secondly, if everyone else who is important, i.e. fraternities and sororities, does it, then to be important, you must drink. Finally, without pare nt instilling morals and good judgment into their children, the students do not think that it is wrong to participate in these activities. All in all, the biggest problem on college campuses is the consumption of alcohol and drugs. If a person was never exposed to the heat of a flame their whole life, and then was thrown into a family barbeque, where they asked this person to cook, how well would they do? They would probably put too much lighter fluid in the grill. Or, they would light the grill while looking at it to see what it did. Or, they would light the grill and then put their hand on it to see what it felt like. All of these things would cause extreme pain to the person who did this. But, would it be their fault? Would it be their fault that they didn’t know how combustible lighter fluid was? It wouldn’t be their fault if they put their hand on it and singed the flesh off of their hand. It wouldn’t be their fault because they were never exposed to it. Th e same thing can be said about drinking and drugs at college. If the person was never exposed to alcohol or drugs and they were thrown into a place where people engage in these activities on a regular basis, of course they would experiment.

Educating Special Needs Students

When it comes to special education, this belief really needs to be a true one because special education teachers will have to deal not only with behavioral students or students with high functioning disabilities but they will also be dealing with autistic students and students with severe intellectual disabilities (Grand Canyon University Course Material 2010).With the basic teaching principle â€Å"all students can learn†, teachers will enable themselves to find ways to help the students in learning social and life skills, get prepared to be independent, get a job and to enjoy quality of life regardless of their disabilities (Grand Canyon University Course Material 2010). Individuals with disabilities can show their frustration with anger, they can feel hopelessness, helplessness and have a sensation of disgust, fear and pity.Many times advocates, educators and even professionals fail by countermanding individuals with disabilities by not properly identifying the intellectual disability. The American Association on Intellectual Developmental Disability (AID, 2008) explains that Intellectual disability is defined as sub-average intellectual functioning but it also should include â€Å"resultant deficits in adaptive behaviors and its occurrence during the developmental period† (Grand Canyon Leistering Course Material 2010).All three conditions must be present in order to determine that intellectual disability is present in the individual. Sub-average intellectual functioning offers to intelligence which is consider as a hypothetical construct difficult to define and is tested with a method called Intelligence Quotient or IQ which consists of several questions and problem solving that gives scores up to 100. Adaptive behavior refers as to the ability of the individual adaptation to the environment and the changes that may come with it.And the third characteristic is the occurrence of a traumatic event which happens to an individual during the develo pmental period which is before turning 18. IQ tests are considered a reliable source of information but according to IDEA 004, â€Å"IQ scores can't be considered the determinant of intellectual disability. Individual personal characteristics and circumstances, cultural bias and low correlation between IQ tests remain issues; moreover a person's IQ changes over time and data over the test provides little and inaccurate information for instruction.Consequently, other definitions focus on individualized needs for supports†. According to AID (2008) causes of intellectual disabilities which happens during the developmental period, may include maternal infections like rubella, syphilis and taxonomists also because of intoxication's like rugs, alcohol, environmental hazards and incompetent blood type transfusions. Chromosomal abnormalities like Downs syndrome. Among others (Grand Canyon University Course Material 2010). Protecting Workers with Developmental Disabilities PAD (n. . ) say that people with mild disabilities can learn academics and vocational skills, those with moderate to severe disabilities can learn basic safe hygiene and self care skills along with social and communication skills and those with profound developmental skills can learn self care skills as well but they may need constant supervision and care†. The majority of the persons with disabilities are capable of learning, develop and grow, and they can become great productive an full participative citizens of the community.With appropriate education and accommodated lesson plans all students should be able to learn. One way to teach students with intellectual disabilities is by providing them with real life representing materials which are appropriate and safe for their age as well as interesting. Provide students with information with clear and easy to follow instructions which is revised in a constant basis. Celebrate accomplishments with positive dieback. Whenever possible and ac cording to the seriousness of the disability, try to teach the student is his regular school.Teach students tasks and skills that they will use in real life in a constant basis so they can relate what they learned to the everyday life(Grand Canyon University Course Material 2010). Another intellectual disability is Autism. This disability was first name and recognized in a district in 1943. It is associated with a series of conditions that include According to Autism Society of America (2000) â€Å"Disturbances of developmental rates, and/or sequences, responses to encore stimuli, speech and language as well as cognitive capacities and capacities to relate people, events and objects.This signs appear before the age of three† (Grand Canyon University Course Material 2010). At one time, autism was included in the definition of emotional disturbance. IDEA (2004) defines autism as an inclusion of serious impairments which include, verbal and non-verbal communication and social in teraction. According to American Psychiatric Association (2000) â€Å"autism spectrum disorders include a spectrum of that goes from Autistic disorder, Aspirer syndrome, Retest syndrome, a event disorder, distortions, childhood disintegrative disorder, and Pervasive developmental disorder.The characteristics include, apparent sensory deficit or hyper reaction to stimuli, Severe isolation or inability to respond to love and cuddly, self stimulation, tantrums and self abusive behaviors which raise the issue of aversive stimuli, calceolaria and psychotic speech and behavior deficiencies â€Å". The possible causes of autism vary and go from one unfounded theory to an-other but according to well known authorities, causes are not known and but evidence suggests that genetics ND biological factors are key.Very' little is still known about autism and because of this fact, educators need to be careful in how they treat autistic students. A therapy which is supposed to be appropriate for t he treatment of autism is dolphin-assisted therapy. It is recommended to provide autistic students with colored lenses to cure dyslexia and also facilitated communication. Lesson planning is key for educators to have success as teachers and help students succeed as well. Intellectual disabled students need extra help and clear one-on-one instruction but they definitely can learn. Educating Special Needs Students Educating special needs students can be challenging for all individuals involved. Students who may have intellectual disabilities, autism, and severe or multiple disabilities can have many bumps along the road of education. The impact of having a disability as a student can affect not only the student and the parents, but the educators as well. Policies, procedures, and programs are put in place to help these students succeed in the world of education. Intellectual DisabilityIntellectual disability is a general learning disability that appears before adulthood. Some people refer to intellectual disability as mental retardation. To define intellectual disability, it includes both a component relating to mental functioning of individuals and functioning skills in their environment. There are three characteristics of an intellectual disability. One is the intellectual quotation or IQ is between 70 to 75 or below.Two is the ability to adapt and carry on an everyday lifestyle such as acti vities, self-care, socialisation, and communication. Three is that the disability occurs prior to the age of 18. Generally the cause of intellectual disability can be caused at birth or during labor; these include temporary oxygen deprivation, premature births, low-birth-weight, and birth injuries. Often times there are a combination of genetics between two people that can form a certain disorder of the gene in their children. A person with a chromosomal disorder, too few or too many chromosomes, can develop an intellectual disability.Educating Special Needs StudentsAutismAutism is a disorder that impairs social interaction in verbal and non-verbal communication. It affects information that is processed in the brain by  altering the nerve cells. Signs of autism are usually noticed within two years of a child's life and the signs develop over time. Sadly there is no known cure for autism but there have been cases reported of children who have recovered. Medical expert have come to the conclusion that autism in some cases have been caused by premature births, early childhood vaccinations, Fragile X syndrome, Rett syndrome, and Tuberous sclerosis. Severe and Multiple DisabilitiesIn individual with severe or multiple disabilities is described as a person who has one or more disability. Some causes can be chromosomal abnormalities, premature birth, lack of oxygen, blindness, deafness, poor development of the brain or spinal cord, infections, genetic disorders, or injuries from an accident. The Individuals with Disabilities Education Act; IDEA made it easier for children between the ages of 3 and 21 to have access to suitable public education. Teachers have found ways to include disabled students in regular classrooms.The Individuals with Disabilities Education Act; IDEA has found a way to have an impact on classroom settings for disabled students. Inclusion classrooms have been beneficial for disabled children. Recent studies have proved that children have been f ound doing better on standardized tests and acquiring better social and communication skills to prepare themselves for life's day-to-day events.Other Educating Special Needs StudentsStudents in the classroom have also benefited by being exposed to disabled students. Other students have grown to accept and develop friendships with students who have disabilities. Students with severe disabilities have curriculums in programs that are specifically altered to fit their needs. A curriculum is set up so that students with learning disabilities will have a brighter future and succeed in their education. It is less likely for students to drop out of school and continue their education by having the stability of a curriculum that works in their favor of learning. Having a functional curriculum teaches students the skills that they need to become an independent individual.When using a curriculum, educators take into consideration what the particular student needs to excel in their course of s tudy and in their classroom. When the educator is aware of what the student  needs they will not waste time in their classroom focusing on areas that a disabled student will not benefit from. Educators will also use multiple instruction methods to help disabled students succeed. Audio and visual learning methods are incorporated to help disabled students overcome their weaknesses and find their strengths when learning. Along with the curriculum socialization skills will help disabled students enter at with others.By developing their socialization skills in the classroom disabled students will become more independent with other members of society. Following a curriculum for disabled students will help them as well as other students except them in the classroom. The benefits of accepting disabled students in the classroom will help them and other students to not segregate them while they are in school learning as well as to teach them the skills they need to interact in life's day t o day events outside of school. Educating Special Needs Students5Policies and procedures in the local school district concerning students with intellectual disabilities use the program Child Find. According to state and federal special education regulations, School Districts, Intermediate Units, and Charter Schools are required to conduct child find activities for children that are eligible for the services of the Individuals with Disabilities Education Act and Section 504 of the Rehabilitation Act of 1973. This program is to identify all children of school age that might need special education all related services due to problems that may interfere with future development and learning.From a legal standpoint each school is required to adopt the use of public outreach awareness. Identify children that are eligible for special education within the school district jurisdiction. Early intervention in special education services and programs must be made know to the public. Each school m ust establish a system to accomplish the necessary initial screening which is to identify and provide a screening of students to identify any academic, social, emotional, or sensory problems concerning vision, hearing, language, or speech difficulties. Teachers and other staff members must assist the students and work effectively with the students in the general curriculum. The child find policies and procedures are used to identify, locate, and evaluate children with disabilities.As early as possible early identification and an  assessment of disabilities will be implemented in a formal plan for the child. The timeline from the initial evaluation must be conducted within 60 days from the parents’ consent for the evaluation. Another program that the school district provides is the Title I of the Elementary and Secondary Education Act and the No Child Left Behind Act. Title I is a financial assisted program that helps schools with high numbers or children with low income fam ilies to ensure that their child meets the academic standards of the state. The No Child Left Behind Act supportsEducating Special Needs StudentsStandards based education reform based primarily on measuring goals that can improve individual outcomes in a student’s education. All public schools receiving the federal funding that comes along with these programs administer a statewide standardized test to all students each year. These text I also provide the parents a detailed report card on their child's performance. Based on the knowledge of the child’s results, it will help the educators and the parents in providing the student with the proper help during their learning years. Over all, learning can be challenging for anyone. But a student with severe or multiple disabilities may face a tough road that many of us may not understand. Having the proper guidelines in place and having everyone involved understand their role in a students learning world is essential to havi ng a successful independent student.