Thursday, March 26, 2020

Poikilohydry in mosses an ecological limitation or opportunity Essay Example

Poikilohydry in mosses: an ecological limitation or opportunity Essay The most significant evolutionary event in the history of the plant kingdom began with the migration of aquatic photosynthetic organisms on to land approximately 475 Myr ago 1,2. Terrestrial embryophytes (referred to as embryophytes) derived from algal ancestors constitute two divisions, the bryophytes (lacking vascular tissue) and the tracheophytes (possessing vascular conducting tissues) 2. The evolutionary transition from aquatic photoautotrophs heralded the innovation of morphological and physiological characteristics critical for success in the terrestrial habitat, and consequent diversification of land plants.It has been hypothesised that early bryophyte related groups pioneered the transition from water to life on land 1,2,4. The mosses appear to be among the most ancient divisions of the land plants. Fossils of spores and gametophytes dating from the Mid Ordivician (~476 Myr) and Mid Sliurian (~432 Myr) have been discovered that closely resemble some modern bryophytes 4. Furt hermore, the remains of fossilised spore-bearing organs and vascular tissues from the Lower Devonian (~410 Myr) reveal similarity in anatomical details to living mosses 4. This paleobotanical evidence combined with phylogenetic studies suggests that groups related to extant mosses are primitive ancestors of the major taxonomic groups of terrestrial plants.In the comparatively uniform environment of aquatic life there is much less scope for variation in abiotic factors and hence natural selection. Light availability vertically through the water column is the major limiting factor. Photosynthetic organisms surrounded by water have no requirement for specialised anatomical features for water absorption, as diffusion occurs across the whole cellular surface, nor do aquatics require adaptive measures to protect against water loss through evaporation. Furthermore, a submersed plant requires no mechanical tissues as the buoyant force of water provides the necessary support 1,5. In contrast , plants entering the terrestrial environment are exposed to a greater variation in the fundamental abiotic conditions including moisture, temperature (rainforest and tundra), light and gravitation.In particular, the land environment exhibits dehydrating affects from the atmosphere and water may be continually lost through evaporation. Water and nutrients may be continuous underground, however, dependence on light requires the aboveground presence of photosynthetic tissue where water is often irregular 1,5. Therefore, suitable water relations are a prerequisite to survival on land. Embryophytes are able to tolerate the desiccating affects of the land environment and exhibit numerous morphological and physiological departures from the ancestral aquatic state. Depending on their ability to compensate for fluctuations in water supply and rate of evaporation, embryophytes may be classified as poikilohydric or homoiohydric 5.Poikilohydry as a limitationMosses represent the oldest living remnants of initial land colonisation. It can be viewed the mosses represent a primitive condition of plant development 4. Mosses can be said to represent an evolutionary intermediate between algal ancestors and the vascular plants, manifested in features that may be more in common with aquatic algae or lichens and are said not to be fully terrestrialised or having a greater reliance on water 4,5,7,8. However, moss gametophytes do exhibit innovations such as tissue differentiation (leaves, rhizoids) and primitive vascularisation 3.It is in the gametophyte form of mosses where the potential for land development in some ecological scenarios may be limited. The gametophyte does not posses a true root and vascular system (xylem or phloem) or outer cuticle, having no control over loss which can be rapid, and internal water content is in equilibrium with that of the atmosphere 3,5. This condition is said to be poikilohydric. Due to this intimate coupling with environmental moisture, mosse s may dehydrate completely in dry air (i.e. no barrier to water loss represented by the cuticle in higher plants)3. Although many moss species can withstand desiccation by dormancy, this comes at an expense of suspending growth and metabolism. They are dependent on availability of free water and mineral slats at the land surface as they do not possess true roots, with rhizoids present for anchorage on the substratum 3. As the root system is deficient, mosses depend largely upon the direct absorption of water through the leaves. Owing to the failure of the gametophyte to produce true vascular tissue with support structures they are unable to attain large dimensions or growth above ground exhibited in higher plants 3,5.Sexual reproduction is facilitated by water (as in algae) via motile male gametes. Only when mosses are covered water can the reproductive organs open and permit the sperm to escape and penetrate the open neck of the archegonium, and thus reach the egg cell. In this reg ard mosses are essentially amphibious in nature, i.e. they require uninterrupted access to water for reproductive success 3,8. As a result mosses may typically be found hugging wet soil, or living in permanently moist habitats, avoiding exposure to turbulent drier air found above the land surface 3,8.Mosses are also set apart from vascular plants on the basis that the non-sexual sporophyte is permanently associated with the gametophyte and never establishes on the substrate. Within higher plants it is recognised that dominance in the land environment is derived from sporophyte of basal archegoniate lineages 2,8. It is evident that in the evolution of the sporophyte, the most significant fact is the progressive reduction of the spore product and increasing dominance of the sporophyte generation in the plants life-cycle, compared with the gametophyte 2. In liverworts the life-cycle of the sporophyte is brief, its exclusive function being in spore production.In mosses the growth period of the sporophyte is greatly prolonged and spore production becomes less important. This trend towards increasing subordination of the gametophyte and increasing importance of the sporophyte in mosses may be manifested in tissue differentiation found in the sporophyte 2. It is evident that the sporophyte of mosses possesses vascular tissue with photosynthetic cells 3. Although the sporophyte is able prolong growth on account of the production of green tissue, it is still dependent on the gametophyte for water. In higher plants, by the development of the root to acquire water from subterranean sources, the sporophyte becomes truly independent 4,.In contrast to the level of developmental complexity present in mosses, it can be argued that homoiohydric characters exhibited in the tracheophytes; a lignified vascular system of xylem and phloem, an impermeable cuticle surrounding vegetative tissues, stomata and seed in higher tracheophytes are a higher state of plant organisation and the ultimate solution to the problem of adaptation to life on land, providing greater independence from water 5. The properties of vascular tissue allow the formation of a transport system conducting water and photosynthate around the multicellular body, thus allowing the development of large complex bodies of roots and leaves7. Additionally, lignified vascular tissue provides a means of mechanical support in large tracheophytes allowing for the erect habit, in contrast to the dorsiventrally flattened posture in mosses7.With an extensive root network, the homoiohydric system allows the maintenance of activity despite sudden changes in humidity as roots penetrate readily available subterranean sources of water i.e. greater period of growth than mosses7. The waterproof cuticle provides a means of reducing water loss trough evaporation and also a barrier to gaseous diffusion. The stomata perforating the cuticles provide avenues for gas exchange, however, also presenting a sight of water l oss. The guard cells limit the rate at which water is lost through stomatal openings via transpiration7. These adaptations exert greater control over water economy and are thus seen to be more effective and dependable than the bryophytic strategy.The tendency in tracheophytes has been to develop reproductive strategies which did not depend on the existence of standing water (e.g., pollen, seeds, flowers). Instead of developing swimming sperm, male gametes are carried in pollen grains from microsporangia with pollination achieved via entrainment into wind or through insects. The development of the seed habit has facilitated the adjustment of plants to strictly terrestrial conditions, with the angiosperms reaching the most perfect expression of the plant organism. Seeds are specialised to resist adverse conditions and can remain dormant until conditions are suitable for germination. Furthermore, the seed may be modified to facilitate dispersal from the parent gametophyte. Thus tracheo phytes have become sufficiently productive to form closed cover over large areas, and is ultimately manifested in the enormous global coverage of phytomass.Poikilohydry as an opportunityWithout a doubt, vascular plants are adaptive optimums within habitats charaterised by adequate soil water. However, the homoiohydric system has success within certain limits defined by temperature and the availability of water 5,7. Mosses are the successors of ecological niches characterised by intermittent water availability due to their ability suspend metabolism during periods of drought (escaping the need for metabolic function) and resume activity rapidly with available water 3,5,6. This feature is known as desiccation tolerance (DT) and is common to various functionally dissimilar species. For poikilohydrous organisms in general, and bryophytes in particular, DT can be argued to be an optimal adaptation to habitats characterised by extreme fluctuations in water availability (i.e. functionally specialised stress-tolerators)3,5. The pervasiveness of mosses in dry habitats provides an alternative perspective on mosses in contrast to the tone already set in this paper.As mosses rapidly equilibrate internal moisture with that of the environment, mechanisms allowing tolerance of dry periods is essential 6. DT is characteristic of a variety of moss gametophytes, and is common of both xeric and mesic habitats 3. DT mosses may colonise rocky, thin soil (drought prone) substrates impenetrable to roots and the bark of trees 5. DT is an obvious adaptive advantage in habitats characterised dry, sun-exposed rock surfaces with intermittent rain. Even in wet climates, moisture is not available continuously. For example, hard substrates dry quickly after rain stops, therefore, DT mosses would possess fitness in this niche5. In this situation it would be an advantage to be small in size1. Growth and reproduction occur only during these wet seasons, but upon drying the gametophyte can susp end metabolism for considerable time periods7. Desiccation tolerance is well documented in mosses.Tortula ruralis can be reduced to 20% of its original weight in 2 hours and even after prolonged periods (10 months) of desiccation resumes metabolic activity within minutes of receiving an adequate water supply7. Andreadea rothii is characteristic of hard acidic mountain rocks, and can recommence normal metabolism after 12 months desiccation at 32% rh and 20OC 5. Recovery takes place quickly, and depends on the conservation of cellular components through the drying-re-wetting cycle5. Chlorophyll-fluorescence measurements show that photosystem recovery after re-hydration is rapid9.The recovery of respiration after prolonged desiccation similarly shows recovery in mosses5. It has been suggested that recovery after desiccation involves the reestablishment of membrane integrity and photosystems10.At the scale of a moss gametophyte colony, surface tension is determines the distribution of w ater around the vegetative tissue5. Therefore, shoots and leaves tend to lie dorsiventrally flattened on the laminar atmospheric boundary5. The LAI of the moss leaf canopies tends to be greater than that of vascular plants and is comparable in some species (Scleropodium spp.) to the mesophyll/leaf-area quotients of vascular plants indicating scale as important determinants of morphology5. Additionally, it can be noted that mosses and vascular plants have similar rates of photosynthesis on a per-chlorophyll basis5. The physical structure of many mosses allows the short term storage of external capillary water3. The hydroid conducting cells of some large mosses (e.g. Polytrichaceae, Dawsoniaceae) may be an evolutionary parallel to the xylem tissue of vascular plants in that both represent a low resistance pathway for water transport3,5. However, typically water movement is extracellular involving intricate conducting structures.The ability of bryophytes to survive desiccation is attri buted to conservation of polyribosomes during desiccation period3,6. In Tortula after 90 minutes in a dry atmosphere, a decline in fresh weight by 20% was observed6. However, it retained distinct polyribosome pools which increased with increasing hydration time3. This is in contrast to vascular plants where extreme water stress induces an irreversible degredation in polyribosome activity. In addition there is evidence to suggest that the activity of antioxidant enzymes is a response in mosses and other DT organisms to oxidative stress induced by desiccation11. Oxidative damage has been shown to be less in DT organisms such as Tortula than desiccation sensitive vascular plants12.In mosses there exists species specific differences in relation to their desiccation tolerance3. It has been observed that mosses characteristic of exposed habitats such as Tortula ruralis can recover rapidly after desiccation5. This may be an adaptation to maximise growth during a water regime that is transi ent. This is in contrast to forest-floor dwellers such as Rhytidiadelphus loreus where recovery of photosynthesis following drying takes several hours more5.There exists approximately 14000 species of moss exhibiting world-wide distribution and are able to grow luxuriantly in the humid climate of temperate and tropical regions.3 Fundamentally, mosses are able to persist in extreme conditions of arctic and alpine regions and can tolerate semi-arid conditions. Largely associated with their remarkable regeneration capacity, mosses exhibit great diversity in the ecological conditions in which they can pervade, proving in particular habitats to be the adaptively optimum plant organism. Poikilohydry in mosses an ecological limitation or opportunity Essay Example Poikilohydry in mosses: an ecological limitation or opportunity Essay The most significant evolutionary event in the history of the plant kingdom began with the migration of aquatic photosynthetic organisms on to land approximately 475 Myr ago 1,2. Terrestrial embryophytes (referred to as embryophytes) derived from algal ancestors constitute two divisions, the bryophytes (lacking vascular tissue) and the tracheophytes (possessing vascular conducting tissues) 2. The evolutionary transition from aquatic photoautotrophs heralded the innovation of morphological and physiological characteristics critical for success in the terrestrial habitat, and consequent diversification of land plants.It has been hypothesised that early bryophyte related groups pioneered the transition from water to life on land 1,2,4. The mosses appear to be among the most ancient divisions of the land plants. Fossils of spores and gametophytes dating from the Mid Ordivician (~476 Myr) and Mid Sliurian (~432 Myr) have been discovered that closely resemble some modern bryophytes 4. Furt hermore, the remains of fossilised spore-bearing organs and vascular tissues from the Lower Devonian (~410 Myr) reveal similarity in anatomical details to living mosses 4. This paleobotanical evidence combined with phylogenetic studies suggests that groups related to extant mosses are primitive ancestors of the major taxonomic groups of terrestrial plants.In the comparatively uniform environment of aquatic life there is much less scope for variation in abiotic factors and hence natural selection. Light availability vertically through the water column is the major limiting factor. Photosynthetic organisms surrounded by water have no requirement for specialised anatomical features for water absorption, as diffusion occurs across the whole cellular surface, nor do aquatics require adaptive measures to protect against water loss through evaporation. Furthermore, a submersed plant requires no mechanical tissues as the buoyant force of water provides the necessary support 1,5. In contrast , plants entering the terrestrial environment are exposed to a greater variation in the fundamental abiotic conditions including moisture, temperature (rainforest and tundra), light and gravitation.In particular, the land environment exhibits dehydrating affects from the atmosphere and water may be continually lost through evaporation. Water and nutrients may be continuous underground, however, dependence on light requires the aboveground presence of photosynthetic tissue where water is often irregular 1,5. Therefore, suitable water relations are a prerequisite to survival on land. Embryophytes are able to tolerate the desiccating affects of the land environment and exhibit numerous morphological and physiological departures from the ancestral aquatic state. Depending on their ability to compensate for fluctuations in water supply and rate of evaporation, embryophytes may be classified as poikilohydric or homoiohydric 5.Poikilohydry as a limitationMosses represent the oldest living remnants of initial land colonisation. It can be viewed the mosses represent a primitive condition of plant development 4. Mosses can be said to represent an evolutionary intermediate between algal ancestors and the vascular plants, manifested in features that may be more in common with aquatic algae or lichens and are said not to be fully terrestrialised or having a greater reliance on water 4,5,7,8. However, moss gametophytes do exhibit innovations such as tissue differentiation (leaves, rhizoids) and primitive vascularisation 3.It is in the gametophyte form of mosses where the potential for land development in some ecological scenarios may be limited. The gametophyte does not posses a true root and vascular system (xylem or phloem) or outer cuticle, having no control over loss which can be rapid, and internal water content is in equilibrium with that of the atmosphere 3,5. This condition is said to be poikilohydric. Due to this intimate coupling with environmental moisture, mosse s may dehydrate completely in dry air (i.e. no barrier to water loss represented by the cuticle in higher plants)3. Although many moss species can withstand desiccation by dormancy, this comes at an expense of suspending growth and metabolism. They are dependent on availability of free water and mineral slats at the land surface as they do not possess true roots, with rhizoids present for anchorage on the substratum 3. As the root system is deficient, mosses depend largely upon the direct absorption of water through the leaves. Owing to the failure of the gametophyte to produce true vascular tissue with support structures they are unable to attain large dimensions or growth above ground exhibited in higher plants 3,5.Sexual reproduction is facilitated by water (as in algae) via motile male gametes. Only when mosses are covered water can the reproductive organs open and permit the sperm to escape and penetrate the open neck of the archegonium, and thus reach the egg cell. In this reg ard mosses are essentially amphibious in nature, i.e. they require uninterrupted access to water for reproductive success 3,8. As a result mosses may typically be found hugging wet soil, or living in permanently moist habitats, avoiding exposure to turbulent drier air found above the land surface 3,8.Mosses are also set apart from vascular plants on the basis that the non-sexual sporophyte is permanently associated with the gametophyte and never establishes on the substrate. Within higher plants it is recognised that dominance in the land environment is derived from sporophyte of basal archegoniate lineages 2,8. It is evident that in the evolution of the sporophyte, the most significant fact is the progressive reduction of the spore product and increasing dominance of the sporophyte generation in the plants life-cycle, compared with the gametophyte 2. In liverworts the life-cycle of the sporophyte is brief, its exclusive function being in spore production.In mosses the growth period of the sporophyte is greatly prolonged and spore production becomes less important. This trend towards increasing subordination of the gametophyte and increasing importance of the sporophyte in mosses may be manifested in tissue differentiation found in the sporophyte 2. It is evident that the sporophyte of mosses possesses vascular tissue with photosynthetic cells 3. Although the sporophyte is able prolong growth on account of the production of green tissue, it is still dependent on the gametophyte for water. In higher plants, by the development of the root to acquire water from subterranean sources, the sporophyte becomes truly independent 4,.In contrast to the level of developmental complexity present in mosses, it can be argued that homoiohydric characters exhibited in the tracheophytes; a lignified vascular system of xylem and phloem, an impermeable cuticle surrounding vegetative tissues, stomata and seed in higher tracheophytes are a higher state of plant organisation and the ultimate solution to the problem of adaptation to life on land, providing greater independence from water 5. The properties of vascular tissue allow the formation of a transport system conducting water and photosynthate around the multicellular body, thus allowing the development of large complex bodies of roots and leaves7. Additionally, lignified vascular tissue provides a means of mechanical support in large tracheophytes allowing for the erect habit, in contrast to the dorsiventrally flattened posture in mosses7.With an extensive root network, the homoiohydric system allows the maintenance of activity despite sudden changes in humidity as roots penetrate readily available subterranean sources of water i.e. greater period of growth than mosses7. The waterproof cuticle provides a means of reducing water loss trough evaporation and also a barrier to gaseous diffusion. The stomata perforating the cuticles provide avenues for gas exchange, however, also presenting a sight of water l oss. The guard cells limit the rate at which water is lost through stomatal openings via transpiration7. These adaptations exert greater control over water economy and are thus seen to be more effective and dependable than the bryophytic strategy.The tendency in tracheophytes has been to develop reproductive strategies which did not depend on the existence of standing water (e.g., pollen, seeds, flowers). Instead of developing swimming sperm, male gametes are carried in pollen grains from microsporangia with pollination achieved via entrainment into wind or through insects. The development of the seed habit has facilitated the adjustment of plants to strictly terrestrial conditions, with the angiosperms reaching the most perfect expression of the plant organism. Seeds are specialised to resist adverse conditions and can remain dormant until conditions are suitable for germination. Furthermore, the seed may be modified to facilitate dispersal from the parent gametophyte. Thus tracheo phytes have become sufficiently productive to form closed cover over large areas, and is ultimately manifested in the enormous global coverage of phytomass.Poikilohydry as an opportunityWithout a doubt, vascular plants are adaptive optimums within habitats charaterised by adequate soil water. However, the homoiohydric system has success within certain limits defined by temperature and the availability of water 5,7. Mosses are the successors of ecological niches characterised by intermittent water availability due to their ability suspend metabolism during periods of drought (escaping the need for metabolic function) and resume activity rapidly with available water 3,5,6. This feature is known as desiccation tolerance (DT) and is common to various functionally dissimilar species. For poikilohydrous organisms in general, and bryophytes in particular, DT can be argued to be an optimal adaptation to habitats characterised by extreme fluctuations in water availability (i.e. functionally specialised stress-tolerators)3,5. The pervasiveness of mosses in dry habitats provides an alternative perspective on mosses in contrast to the tone already set in this paper.As mosses rapidly equilibrate internal moisture with that of the environment, mechanisms allowing tolerance of dry periods is essential 6. DT is characteristic of a variety of moss gametophytes, and is common of both xeric and mesic habitats 3. DT mosses may colonise rocky, thin soil (drought prone) substrates impenetrable to roots and the bark of trees 5. DT is an obvious adaptive advantage in habitats characterised dry, sun-exposed rock surfaces with intermittent rain. Even in wet climates, moisture is not available continuously. For example, hard substrates dry quickly after rain stops, therefore, DT mosses would possess fitness in this niche5. In this situation it would be an advantage to be small in size1. Growth and reproduction occur only during these wet seasons, but upon drying the gametophyte can susp end metabolism for considerable time periods7. Desiccation tolerance is well documented in mosses.Tortula ruralis can be reduced to 20% of its original weight in 2 hours and even after prolonged periods (10 months) of desiccation resumes metabolic activity within minutes of receiving an adequate water supply7. Andreadea rothii is characteristic of hard acidic mountain rocks, and can recommence normal metabolism after 12 months desiccation at 32% rh and 20OC 5. Recovery takes place quickly, and depends on the conservation of cellular components through the drying-re-wetting cycle5. Chlorophyll-fluorescence measurements show that photosystem recovery after re-hydration is rapid9.The recovery of respiration after prolonged desiccation similarly shows recovery in mosses5. It has been suggested that recovery after desiccation involves the reestablishment of membrane integrity and photosystems10.At the scale of a moss gametophyte colony, surface tension is determines the distribution of w ater around the vegetative tissue5. Therefore, shoots and leaves tend to lie dorsiventrally flattened on the laminar atmospheric boundary5. The LAI of the moss leaf canopies tends to be greater than that of vascular plants and is comparable in some species (Scleropodium spp.) to the mesophyll/leaf-area quotients of vascular plants indicating scale as important determinants of morphology5. Additionally, it can be noted that mosses and vascular plants have similar rates of photosynthesis on a per-chlorophyll basis5. The physical structure of many mosses allows the short term storage of external capillary water3. The hydroid conducting cells of some large mosses (e.g. Polytrichaceae, Dawsoniaceae) may be an evolutionary parallel to the xylem tissue of vascular plants in that both represent a low resistance pathway for water transport3,5. However, typically water movement is extracellular involving intricate conducting structures.The ability of bryophytes to survive desiccation is attri buted to conservation of polyribosomes during desiccation period3,6. In Tortula after 90 minutes in a dry atmosphere, a decline in fresh weight by 20% was observed6. However, it retained distinct polyribosome pools which increased with increasing hydration time3. This is in contrast to vascular plants where extreme water stress induces an irreversible degredation in polyribosome activity. In addition there is evidence to suggest that the activity of antioxidant enzymes is a response in mosses and other DT organisms to oxidative stress induced by desiccation11. Oxidative damage has been shown to be less in DT organisms such as Tortula than desiccation sensitive vascular plants12.In mosses there exists species specific differences in relation to their desiccation tolerance3. It has been observed that mosses characteristic of exposed habitats such as Tortula ruralis can recover rapidly after desiccation5. This may be an adaptation to maximise growth during a water regime that is transi ent. This is in contrast to forest-floor dwellers such as Rhytidiadelphus loreus where recovery of photosynthesis following drying takes several hours more5.There exists approximately 14000 species of moss exhibiting world-wide distribution and are able to grow luxuriantly in the humid climate of temperate and tropical regions.3 Fundamentally, mosses are able to persist in extreme conditions of arctic and alpine regions and can tolerate semi-arid conditions. Largely associated with their remarkable regeneration capacity, mosses exhibit great diversity in the ecological conditions in which they can pervade, proving in particular habitats to be the adaptively optimum plant organism.

Friday, March 6, 2020

Black Stereotypes essays

Black Stereotypes essays The American society has oppressed the black culture and society since the first slave was dragged onto American soil. Hollywood first embraced this oppressed image and depicted it on film. Early depictions of blacks on film (commonly played by whites in blackface) fulfilled the white stereotype of black society. As the American culture advanced, the image of blacks created on film was also altered. Blacks experienced a period of "whiteness" on film. During this time, Hollywood utilized "the equal-by-being-superior philosophy." (Bogle 178) This role was most successfully played by Sidney Poitier. As the cycle continued, the image of blacks on film regressed back to stereotypical depictions. Only this time blacks played the stereotyped characters. David Wark Griffith's epic film The Birth of a Nation (1915) used white people to play black characters. The whites wore blackface, common for the time, to create the appearance of being black. Under this guise, whites were able to portray a stereotyped depiction of the black people. The NAACP opposed the film immediately. Griffith himself was puzzled by the reactions. Griffith argued that The Birth of a Nation was about war and reconstruction, not race. This stance Griffith had taken only furthers the stereotype created on film. The idea that Griffith did not realize he was creating a highly racist film signifies the attitude of society at the time. It points to the idea that much of the American culture, at the time, was passively racist. They views that society had come to accept as reality, was not reality at all. The black depiction, as seen in The Birth of a Nation, continued for several years until Hollywood film reached another turning point. This turning point was the height of the integrationist era. The integrationist age spanned from about the mid to late 1940s to the late 1960s and into the early 1970s. During this age, several ac ...

Wednesday, February 19, 2020

Choose one from the document that i uploaded Essay

Choose one from the document that i uploaded - Essay Example The recently established Securities and Exchange Commission has already charged more than a hundred culprits in crisis related cases as of July 18 this year. The federal law enforcers focus mainly on placing civil charges instead of criminal penalties against senior executive officials from the Wall Street business organizations. In the process of seeking justice in the United States economy, the federal law enforcers were forced to carry out in depth investigations in the American financial industry. Currently their mandate is to assess the current policies and modify the set of orders. The clock is quickly ticking and the law enforces have no other role rather than to finally make sure justice is attained in the American economy (Kuttner 243). According to the report written by Williams, it is evident that during the economic crisis, individuals vandalized the economic stability through fraud. According to the report which was featured by the Reuters and the Bloomberg, rigging was done on the LIBOR, i.e. the London interbank offered rate. This had a major repercussion on the returns that the banks were to make and in turn, the amount that was to go to the state. So much rigging would obviously be reflected in the state’s economic balance. Additionally, corruption and impunity masked the entire process since traces to the lost money

Tuesday, February 4, 2020

Practice of Research Assignment Example | Topics and Well Written Essays - 250 words

Practice of Research - Assignment Example Being one of the most challenging activities in the research process, reviewing of the available literature is an important principle. It enables the researcher come up with a researchable problem. In their book titled â€Å"Practical Research: Planning and Design,† the authors Leedy and Ormrod (2010) put forth the statement that, â€Å"the existing literature is likely to tell you what is not known in the area- in other words, what still needs to be done.† Reviewing the available literature will expose the researcher to several areas of concern with the likelihood and expectation that he or she will generate sub-problems from the material before going to the major problems. Identifying a problem related to the researchers themselves is important since it will naturally motivate them into researching more (Leedy & Ormrod, 2010). After identifying this kind of problem, the researcher should then focus on the purpose of the research at hand with the ability of developing substantial

Monday, January 27, 2020

Social Issues of E-Commerce

Social Issues of E-Commerce Social Issues of E-Commerce Nowadays, the internet has created a new function called e-commerce. E-commerce is commonly known as electronic commerce and now already become a virtual main street of the world. It is essentially cover all the activities on internet and induce the customer to purchase the product over the internet. Thus, it is another way to running their own business over the internet and it used to selling and buying the product over the internet with other business man and customer on other state. E-Commerce is a good way to do their business because it can enlarge their business to whole world so that they can do their business bigger and makes more money in future. Besides that, it also can let more people know more about their product by seeing the picture of product that they upload and the details of the product that they list out on internet. Other than selling and buying product over the internet on e-commerce, it also have another function on e-commerce called supply chain management, e lectronic data interchange (EDI), electronic funds transfer, inventory management, online transaction processing, and data collection systems to make it more easy for business man for selling their product. I choose this subject to discuss their issues because e-commerce is the most popular on the internet and it has been become a virtual main street of the world. Besides that, it also has many issues for us to discuss so I decide to choose this subject to discuss. First, I will discuss the issues for e-commerce is security privacy. It is the most important issues for e-commerce because without security privacy, the customer will scared get cheated by the seller. For example, the customer will scared the seller products whether is good or bad because they just saw the picture of the product over the internet so the customer dont know whether the product are good or bad so they scared the seller will post up a bad thing to sell at internet. Another example is scared after the customer transfer the money to the seller then they wont send the product to the customer. Other than this 2 example, there still have another example is the customer dont know the actual price at marketing and t he seller just simply set up the price and did not follow the marketing price to gain their profit more than market price such as double or triple from the market price. These 3 examples will be the impacts of society because if the seller fraud the buyer then the society will become lower standard. Moreover, the impacts of IT industry is the buyer will not visit the web-sites again to purchase their products so that it will affect IT department said that e-commerce is not good in use on internet to do business because the buyer get cheat by the seller and they wont online to purchase the products again and they would rather buy the products on marketing by finding the products themselves. Besides that, there still have other issues of e-commerce. The second issues that I will discuss are shipping issues. Shipping issues means that when the buyer buys a product from the seller and the seller is from other state then they should use shipping to send the products to the buyer so that it can arrive to the place of buyer stay. In shipping, there need to have a good data management means that the seller need to manage the data securely such as addresses of buyer, names of buyer, credit card information of the buyer, and contact information of the buyer. They need to have a good management on this because if the seller never manage the data of the buyer securely and just simply write it down only then when they need to send the products to buyer after confirm all the transaction then only feel that some information already lost due to the paper that list out the buyer details cant find it out then it will become a shipping issues because without the information of the buyer then they cannot send the product to the buyer so when the buyer did not receive any products that they promise before with the date that the product will arrive to the buyer then the buyer will feel that they get cheat by the seller. Its very important because if the buyer feels they get cheat by seller then they wont go to that websites again to purchase the products. Besides that, for shipping fee, it is calculate with the weight of the products so after calculate the price out for shipping fee then it still need to add up the cost of the products so it will become a very high cost for the products compare with marketing price so it will cost highly if want to purchase the product over the internet and the seller are not stay in your country. These issues will affect the society become low standard if the buyer fell they get cheat by the seller and the buyer will think that mostly of the seller that stay at that country also same with him/her so their country will become low sta ndard. Besides that, these issues also will affect IT industry because the buyer will fell that although using internet to purchase a product is more easy but need to pay double or triple of the marketing price and they will they better buy themselves and not purchase though the internet so that it can saves more money compare with purchase online then the buyer will not use the internet again to purchase product so IT will become less people used for purchase products. Other than 2 issues above, there still have another issues called complexity of process. It means when the buyer want to purchase that such products then they need to follow their step to purchase a products from them such as register as a member of that website, fill up the agreement form, key in all your personal details, key in your credit card number and so forth. There have many step to follow if want to purchase a products over the internet. Although many step to do before purchase the products is for the best security privacy but the buyer will feel that the process of buying the products over the internet are complexity compare with buy a products outside. These issues also will be the same impacts to society and IT industry such as the society will become low standard and cannot progress to become better, and IT industry also will become not many people to use IT to purchase the products over the internet. Conclusion, after we discuss these all the issues for e-commerce, we already know that what is the impact of that all issues to society and IT industry so we need to learn from the issues so that we can make it better and improve the efficiency for e-commerce. First, we need to increase the security privacy such as build up a good impression for your website which is do not fraud people and so forth so that the buyer can trust your website when they want to purchase products. When the buyer trust your website then our society will become more high standard because nowadays they are using ecommerce to purchase products. Secondly, we need to decrease to shipping issue such as have a good data management so that the data wont get lost. Moreover, we also need to find out the economical ways to ensure that your products will arrive to the buyer with the time that you promise before and the shipment fee will not cost highly so that the buyer will always keep purchase products over the in ternet. When the buyer feel that shipment fee and product fee is a good cost and not cost highly then the buyer will keep purchase the products from your website so it can improve our society and also IT industry. Lastly, we need to reduce the step before purchase products such as we just ask the buyer to fill up his/her details that can contact his/her then uses email to verify again their details and then only send out the products to the buyer so that the buyer wont feel the process of purchase a product complexity and they also will always use internet to purchase the product so our society can become high standard and IT industry also will have a good feedback from user. After discuss how to reduce the issues of e-commerce, I believe that e-commerce will become more users friendly and will become a virtual main street of the world so they can purchase any products that they need over the internet. Reference wikinvest(2006), http://www.wikinvest.com/concept/E-Commercewebz, http://www.webz.com.my/ec.html goecart(2000), http://www.goecart.com/support/ecommerce-issues.aspx AllBusiness(1999), http://www.allbusiness.com/sales/internet-e-commerce/842-1.html EzineArticles(2009), http://ezinearticles.com/?General-eCommerce-Issuesid=182160

Saturday, January 18, 2020

Leading By Example

How we relate to others is as varying as the stars In our solar system. For some, political leaders like Bark Obama and Sarah Plain display specific attributes on a dally basis. These characteristics are recognized globally as pillars of change and structure in today's American society. Although not every decision these persons in power choose is supported by â€Å"the people†, it is easy to question where their particular morals come from. Reflecting on my own personal exposure to literature such as â€Å"To Kill a Mockingbird† by Harper Lee, I imagine examples such as TacticsFinch stood as a concrete Image for current world leaders to model their behaviors after. Like Tactics, today's leaders face challenges maintaining personal Integrity, human decency toward others, courage, and respect both by and for one another. Those who have read the book may easily agree to the belief that Tactics truly was a great leader by utilizing these concepts in his daily life. His abil ity to connect to others on even the most challenging of levels shows the true courage needed to lead a community which is not truly united.It was during the cultural mixing of the sass's hat Lee's â€Å"To Kill a Mockingbird† shows the first acknowledgement of change for the country leadership. Although the character of Tactics exists wealth the pages of Lee's creation, leaders like Tactics stand out as influential members of society, both in personal and civic relationships. While discussing the famous trial case of Tom Robinson Tactics explains to his daughter Scout the importance of valuing others' opinions when they don't align with your own.He says, â€Å"They're certainly entitled to think that, and they're entitled to full respect of their opinions. But before I can live tit other folks Eve got to live with myself. The one thing that doesn't abide by majority rule Is a person's conscience. † In attempts to also bring peace to an escalated situation President Ob ama shared words encouraging mutual respect. William Scott Harrow details the address given by Bark Obama focusing on Iran's policy on mutual respect matters. â€Å"To denounce or shrug Off call for cooperation is an easy but also a cowardly thing to do.That's how wars begin. That's where human progress ends†¦ A sustained effort†¦ We need to find common ground, to focus on the true we seek for our children, and to respect the dignity of all human beings. † As I listen to friends share memories of ‘To Kill a Mockingbird†, a common word has been repeated by each of them, courage. Their eyes lit up with appreciation, thinking about the numerous times where Tactics demonstrated courage. Whether he was essentially forced to shoot a senile pet or fending off a crowd of angry townsmen he maintained a state of focus.It was during these times Tactics shared with his son the importance of taking a stand and having courage to lead others, even when they don't all a gree with you. He says totes, â€Å"A mob's always made up of people, no matter what. Mr.. Cunningham was part of a mob last night, but he was still a man. † Instead of being angry with the dangerous group Tactics embraced compassion and faith, not fear. Keeping in mind that our economy harbors countless ideals of morality and human decency, I am reminded off quote Sarah Plain expressed during an Interview. â€Å"Faith that every baby Is created for a good purpose†¦ Plain was agree with the belief that all existing humanity deserves an enriched life, but the agree to how this point of view is mandated oftentimes sits uneasy with the majority of communities. Nonetheless Plain leads other groups in harmony, sharing one direction. Tactics Finch, during his time, was not among the many. His view of public decency was held higher than the general person. This did not allow him, however, to lessen his sense of retribution. He so greatly believed the actions taken for one man resulted in the good for humanity. This is why so many did have respect for him.Without negating the position of others Tactics respectfully managed a mom absent of a mother for his two children. Surrounded by women with means to raise Gem and Scout, Finch chose to take an active role as a mentor and father. This compassion earned the greatest respect of all, from Scout. And as any true leader does, succession brings action. â€Å"So I took an eight-year old child to bring ‘me to their senses, didn't it? That proves something-that a gang of wild animals can be stopped, simply because they're still human. Humph, maybe we need a police force of children†¦ Oh children last night made Walter Cunningham stand in my shoes for a minute. That was enough. † Acknowledging growth fosters the greatest forms of leadership. This story shows true life examples of how today we have the opportunity to create value from pain and injustice. Scout's connection to reality through her r elationships help demonstrate the effectiveness of Finch's role as a leader. Harper Lee described Scout's experience through the sight of a child, although speaking with an educated dialect. The example led by Tactics Finch trickled down on a daily basis.

Friday, January 10, 2020

Why We Crave Horror Paper

Essay 5: Position Paper50 pts Description:4-5 pages, double-spaced, plus a separate MLA-format Works Cited page Skills:Everything! Due:First Draft:Friday, 10 December (in-class discussion) Final Draft:Monday, 13 December (Submit during Final Exam time: 2:45-4:45pm) Sources:Reading Critically, Writing Well (RC) pp. 517-534, 582-595; Stephen King, â€Å"Why We Crave Horror,† â€Å"Crouch End;† Fritz Leiber, â€Å"Smoke Ghost;† Algernon Blackwood, â€Å"The Empty House;† Noel Carroll, â€Å"The Nature of Horror† (optional)For your final paper, you will be required to make use of the above resources to explain, support, and defend your position against critique on the subject of horror in the absence of easily identifiable violence, gore, or monsters. You may argue with or against King and Carroll, or provide your own definition of horror and how it anticipates gore-less horror better than previous definitions. Since there are no right or wrong answers in this discussion, you will be judged on the strength of your argument for your position and how you present your analysis. Assignment: ) Present the issue. †¢ Summarize the King and Carroll definitions of horror and their successes/failings.†¢ Establish your credibility by generously discussing previous arguments on the function of horror. o Make sure to avoid emotional/personal opinions and instead stick to the texts. 2) Assert your position. †¢ Give examples from the readings that fit well/do not fit with the definition of horror as presented by King and Carroll. o Critique your own analysis using any of the Developing Your Argument skills (RC pp. 360-361), as well as Evaluating the Logic of an Argument (p. 24-640. 3) Argue directly for your position. †¢ Continue to establish your credibility with your audience by showing how your position alters/upholds the definition of horror as established. o Be willing to take a side in the argument, but avoid setting up straw-man arguments for the opposition. Carroll and/or King don’t have to be wrong for you to be right.4) Critique any relevant counter-arguments, objections, questions, or alternatives. †¢ Since no position will be perfect, try to accommodate any concerns or issues relating to your discussion of horror. Options (you may choose one or all): ? Accommodation: modify your position to suit relevant objections. ? Refutation: show the reader that any likely alternatives will not be as effective in describing the function of horror as you see it. ? Integration: demonstrate how your position can work together with other options to provide a more comprehensive take on the horror genre.Criteria for Evaluation: †¢ Analysis: 20 points o Has a strong, focused explanation of the sources using RC skills learned so far. o Supports the initial thesis with evidence (i. e. details from the source) and offers in-depth analysis of those details. †¢ Sources: 10 points o Productivel y uses both the RC and the sources. o Features effective paraphrasing and selective quotation. †¢ Organization: 10 points o Offers strong topic sentences that logically develop and extend the analysis (i. e. , no random accumulation of facts or bullet-point narrative). o Proceeds logically from one point to the next in a climactic sequence. o Clearly links claims and evidence. o Uses smooth transitions between points. †¢ Readability: 10 points o Uses correct grammar, spelling, punctuation, and MLA citation.