Saturday, August 24, 2019
Mass communication - Essay Example Moreover, the analysis will consider the two pertinent arguments that seek to define the ways in which the media and culture interact with society. For such a purpose, it is necessary to view Ã¢â¬Å"the mediaÃ¢â¬ as a solitary entity rather than a conglomerate of multi-dimensional pieces. Although such a definition is somewhat simplistic, it is one of the only ways that such a broad topic can be attempted to be researched and answered in such a brief piece. Firstly, many scholars have sought to portray the way in which the media interacts with and defines culture as a mechanism by which one is forcefully shaping the other in a way that exhibits the strength and power of one over the other. This approach has been used by many to draw a level of inference with respect to the ways in which the media has a direct or indirect effect in attempting to mold and direct the shape of a given culture (Salomon 1997, p. 379). As such, this interpretation necessarily takes the view that the medi a is somehow operating in a type of vacuum and has the strength to both mold and shape the beliefs, attitudes, and norms/mores of society in which it interacts. Although this can to a large extent be realized to be partially true, the fact of the matter is that the media is itself integrally tied to the concept and understanding of culture. In this way, it cannot be fully understood to be a foreign force that is acting upon culture as a means to influence it. However, to the credit of those that espouse such a view of the media, it should be understood that recent changes and direction in the media actually helps to add a degree of credence to such a worldview. Years past, the media itself was a massive conglomeration of different firms and interests that could be divided amongst radio, television, movie industry, newspaper, magazine, entertainers, production entities etc. However, there has been a definite and pronounced trend within the past 30-40 years to have what can only be de fined as a more integrated representation of the media within our world. This is not the result of some sinister plot to control the minds and culture of our current society; rather, it is merely the fact that the media industries are like any other business and seek to continually differentiate themselves and seek out new opportunities, reduce competition, and open themselves to new markets and new consumers of their products. As a means to earn more profits and generate a higher degree of market share, mergers have been a trend within the media industries for the better part of the past several decades. As such, the aforementioned groups that make up the media industry within the world have become more and more related; thereby creating a situation in which but a handful of dominant media firms seemingly dictate multiple sectors of the media. This has caused many people to assume that due to the non-penetration of free market players into the industry it necessarily means that the media as such has a powerful and monopolistic effect on interacting with and defining culture (Mallia 2011, p. 33). However, as will be analyzed in the proceeding section, such an approach is somewhat narrow-minded. Due to the fact that each of these media sectors ultimately seeks to operate in the same way that any firm would (i.e. to generate profits), the behavior of the entity is not unpredictable or
Friday, August 23, 2019
NAFTA - Essay Example An understanding of the economic effects and the benefits of this agreement is important for those personnel who are to be stationed in near shore positions located in Mexico or Canada. The first benefit for large American based companies who choose to deploy a part of their operations in Mexico or Canada is the economic advantage of lowered recruitment and Human Resource Cost for skilled and unskilled labor as compared to the economic market in America (Wikipedia, 2006). Additionally, American operations managers and executives of companies working in Mexico have the advantage of a higher standard of living in Mexico since the cost of living is lower (World Bank Group, 2001). After a decade of free trade with America, the Mexican economy like the Canadian economy has become very closely linked to the American economic system. NAFTA therefore is essential for MexicoÃ¢â¬â¢s continual growth and economic survival as a trillion dollar plus economy. With NAFTA the economy of Mexico has experienced booms but there is still some controversy about the application of the rules under NAFTA (Wikipedia, 2006). The opposition mostly comes from the economic crisis which Mexico went under soon after the signing of the treaty in 1995. However, the data collected by the World Bank and other economic agencies show that NAFTA has been mostly beneficial for the economy of Mexico since the poverty rated have gone down and economic improvement has resulted in greater job opportunities for the Mexican people. Real incomes and salaries have been on the rise and if the government continues to invest in education and other public projects for development Mexico could become one of the fastest growing economies of the world (World Bank Group, 2001). While the trade between the countries has been liberalized like the European Common Market, the national sovereignty of nations has not been changed and the laws for
Thursday, August 22, 2019
War of 1812 Essay The War of 1812 was a war that lasted for two years that helped the United States to firmly and officially establish its independence. After finishing with the concern of France, England turned its attention over to the United States. At first, the United States did not want to resort to war and fighting (Doc. B) but rather sort out their issues economicallybecause England had seized all ships that did not stop in the British port before heading to their other European destinations, Congress passed the Embargo Act and then the Non-Intercourse Act, allowing trade with all nations except France and England. Then, England refused to allow this trade to occur, so America had to resort to war. The Northeastern Federalists were not in favor of war, but the Republicans ultimately won the majority vote in Congress to declare warthe War of 1812 (Doc. G). During this war, America was very concerned with gaining control over land in this country as well as in Canada, but at the same time Americans needed to defend themselves against their strong British enemies. Either way, America had to abandon its position of neutrality (Doc. C). During the war, Britain was very effective in fighting the Americans during many battles, so we needed to defend ourselves in every way possible, and often we were successful. In addition, America wanted to take revenge on the British for taking people from American ships and forcing them to work in the British Navy. The British were able to make their way via water to Washington, D.C. and burn down many parts of the city. After weakening the capital, they set off to Baltimore Harbor but Fort McHenry had already blocked their path, so the British actually had to attack from afar, which ended up not being so effective. America also blocked the British from success in the Battle of Plattsburgh. The United States was successful in capturing Lake Ontario and Lake Eerie, causing them to have very easy access to Canada. By being able to enter Canada, William Henry Harrison led the soldiers to kill Tecumseh in the Battle of Thames, making this a great victory over the Native Americans. This does seem like an unnecessary battle done completely out of greed for control, but the defeat of the Creeks (allies of Tecumseh) in the Battle of Horseshoe Bend was helpful for the Americans in that Andrew Jackson led his men to destroy the tribe because they had been attacking whites along the Floridian border, and we annexed aÃ section of Florida (Doc. D). Although the Indians may have thought that the Americans only wanted to take over their lands (Doc. F), America was not out to hurt the Indianswe actually wanted to be on good terms with thembut Madison made them aware that if it is necessary, Americans will fight them in order to protect their own well-beings (Doc. E). Ending the War of 1812 was the Battle of New Orleans, when the British were planning to attack, but Andrew Jackson was ready with his men to destroy their enemies, and they were victorious. The War of 1812 officially ended with the Treaty of Ghent, which stated that America did not gain Canada, that impressments would not stop, and that America would have to return some land to the Indians (this statement was not really obeyed). But, a few other small treaties were written that allowed America to trade freely with England. All of the various battles aforementioned except for the Battle of Thames were ones that were instigated by the British and the Americans saw no other way to deal with their enemies but to defend themselves. This does not connote that the Americans fought this war in the first place out of greed or land hunger. Although the British did make many attacks on the United States during the War of 1812 and Americans did indeed need to defend themselves, America did not have entirely pure intentions (defense and struggle for complete independence were not the only reasons). During this rather pointless war, America had hoped they would annex Canada, and that is why the Battle of Thames occurred. The United States also wanted to cede Florida, hence the Battle of Horseshoe Bend. In addition, because the Republicans held the majority in Congress, President Madison felt he needed their support (Southern and Western states). The opinion of these states, expressed by Henry Clay (a War Hawk), was that the country needed to go to war because they wanted to gain land and they were concerned over the falling prices of agricultural products and therefore the restriction on trade. America entered this war caring only about the white citizens and not really about how the Indians would be affected by their hopes for the end results of the war. Americans did enter the war with hopes of annexing land, but the end result was completely different from the initial goals. After much unnecessary fighting, America left the war victorious in her own waythe country was finally completely free to do as she pleased, and the country was officially independent of any and all other foreign powers.
Wednesday, August 21, 2019
Historical Vacation in Nevada Essay At present, Nevada is one of the largest and the best states in the U. S. Visiting this state simply means not finding a shortage of action. Nevada is one of the only places in the States where it is possible to perform morning ski world-class runs and afternoon world-class green walks. Nevada is also famous for Tahoe Rim Trail, Truckee River, Sand Mountain, and world-class shows and dines and world-famous casino and resorts. Aside from these, Nevada is also a state rich in culture and history. This is the reason why with my time machine, I decided to visit Nevada with my History professor. I chose to visit Nevada with my History professor because I thought that he is the best person who can help me understand special places and people in this state. However, with so many periods and so many places to explore, I asked my History professor, where should we begin? Historical Vacation in Nevada I had quite a long discussion with my professor about the places, period, and events to visit. After a long discussion, we both agreed to take my time machine and go back to the 19th century where some of the famous Nevadans, in the field of politics and arts, existed. For our first destination, my professor asked me to set my time machine to the 19th century. With a wink of an eye, we landed on a very beautiful place. I was very surprised to see mansions, 19th century houses, imported furniture, stylish fashion which seem to have come from the Orient and Europe. I had the impression that this place was a very boisterous town. I asked my professor if he knows this place. At first, he didnÃ¢â¬â¢t have any idea until we saw gold in the hills and dollars being made. I saw my professorÃ¢â¬â¢s eyes widened while saying Ã¢â¬Å"We are in Virginia City, Nevada! Ã¢â¬ We walked around the beautiful town and we saw a man walking on the street. My professorÃ¢â¬â¢s face brightened up and he told me that this man is a very important man in the history. I looked at the manÃ¢â¬â¢s face and realized that I saw it once in one of my history books. I suddenly remembered; this man is none other than William Morris Stewart! My professor explained that Mr. William Morris Stewart was one of the participants in the mining litigation in Virginia City, Nevada in 1860. He also helped and played a big role in the Comstock LodeÃ¢â¬â¢s development. Nevada became a state in 1864 and Mr. Stewart helped in the development of the StateÃ¢â¬â¢s constitution (Smith, 1943). However, his role in the state as a politician and lawyer had always been very controversial. He was accused by his opponents of bribing juries and judges (Plazak, 2006). Despite this, Mr. Stewart was still elected as a Republican in the United States Senate in 1864 and served until 1875. He was again elected to the United States Senate in 1887 and was reelected in 1893 and again in 1899. During his term in the Senate, Mr. Stewart co-authored or drafted important legislation, including land reclamation laws and mining acts. However, he became famous for authoring the 15th Amendment to the US Constitution in 1868. This amendment promotes the protection of peopleÃ¢â¬â¢s voting rights regardless of color, race, or previous servitude condition. It was a great pleasure to learn about the contributions of Mr. William Morris Stewart but of course, it was really a great pleasure to experience visiting Virginia City. We went back to my time machine and went to a slightly different setting but also in the same period, the 19th century. When we landed, what I saw was not at all as beautiful as what I saw in Virginia City. I had the impression that we were in a ghost town. It was so dusty, hot, humid, and all I could smell was dust. I asked my professor where we were and he told me that were in Goldfield, one of the important cities of Nevada. I was surprised because it was so different from the Goldfield I know of during my time. While wandering in this ghost town-like place, we saw Mr. George Wingfield, the man behind the Nevada business mining camps. Once again, my History professor explained that Mr. Wingfield converted the useless mines of Nevada into great mines. He was one of the greatest organizers that put mining companies into operation (Time US, 1937). My professor further explained that Mr. WingfieldÃ¢â¬â¢s first mining venture in the State was in Golconda copper mines. It was a hard time for him as he was practically stripped off and had a gold fever but he was not discouraged. He was also the man behind the fight against the Western Federation of Miners and Industrial Workers of the World. These two organizations controlled the situations in the mine and George Wingfield was so determined to go against the orders and he succeeded, giving freedom to majority of miners in the mines. Again, it was a pleasure for me to know that Mr. George Wingfield was behind the success of Goldfield. For our last destination, my professor decided to go to early 20th century of Reno. I was so fascinated to see that Reno in the early 20th century was not at all so different from the Reno I know of. I was entertained by the peculiar neon marquees as they cast an outlandish nighttime glow on NevadaÃ¢â¬â¢s ever famous Truckee River. From a distance where my professor and I were standing, we could see the hotel towers as they punctuate the high-desert setting of the city between the arid Great Basin and the Sierra NevadaÃ¢â¬â¢s eastern slope. However, what I wonÃ¢â¬â¢t forget about this early 20th century to Reno is my encounter with Mr. Robert Cole Naples, one of the famous painters of the USA. My professor and I agree that he had contributed a lot in the American art. References Smith, Grant. (1943). The History of the Comstock Lode. Univ. of Nevada Bulletin, 37(3), 69. Plazak. Dan. (2006). A Hole in the Ground with a Liar at the Top. Univ. of Utah Press 10: 0-87480-840-5, 26-27. Time US. (1937). King George. Retrieved 04 May 2009 from http://www. time. com/time/magazine/article/0,9171,770884-2,00. html.
Tuesday, August 20, 2019
Effects of donepezil in healthy young adults Rationale: The cholinergic system is involved in the modulation of both bottom-up and top-down attentional control. Top-down attention engages multiple executive control processes, but few studies have investigated whether all or selective elements of executive functions are modulated by the cholinergic system.. Objective: To investigate the acute effects of the pro-cholinergic donepezil in young, healthy volunteers on distinct components of executive functions. Methods: We conducted a double-blind, placebo-controlled, independent groups design study including 42 young healthy male participants who were randomly assigned to one of three oral treatments: glucose (placebo), donepezil 5 mg or donepezil 7.5 mg. The test battery included measures of different executive components (shifting, updating, inhibition, dual-task performance, planning, access to long-term memory), tasks that evaluated arousal/vigilance/visuomotor performance, as well as functioning of working memory subsidiary sy stems. Results: Donepezil improved sustained attention, reaction times, dual-task performance and the executive component of digit span. The positive effects in these executive tasks did not correlate with other attentional arousal/visuomotor/vigilance measures. Conclusions: Among the various executive domains investigated donepezil selectively increased dual-task performance in a manner that could not be ascribed to improvement in arousal/vigilance/visuomotor performance nor working memory slave systems. Other executive tasks that rely heavily on visuospatial processing may also be modulated by the cholinergic system. Cholinergic manipulations consistently alter sensory-driven, bottom-up attention but their effects on top-down, controlled processing have been less explored (e.g. Furey et al. 2008b; Hasselmo and Stern 2006; Sarter et al. 2001; Thomas et al. 2008), specially as pertains executive functioning. Executive-type processing comprises a wide range of cognitive processes that have a role in the control of action and are considered a function of the central executive in the multiple component model of working memory (see Baddeley 2007, p. 11; Repovs and Baddeley 2006). In the latest version of this model the central executive is responsible for manipulating information contained in subsidiary slave components that store information of different modalities for short periods of time, as well as information activated from long-term memory (Baddeley 2007; Repovs and Baddeley 2006). Today, executive processing is considered a multiple construct, consisting of different cognitive domains or components that, despite being correlated, are dissociable (Collette et al. 2006; Fisk and Sharp 2004; Friedman et al. 2006; Mantyla et al. 2007; Rabbitt 1997; Smith and Jonides 1999). Miyake (2000), in their influential paper on the diversity of executive functions, showed the dissociability of four postulated executive functions: updating, or modification of the content of working memory by deleting no longer relevant information and incorporating more relevant data (Miyake et al. 2000; Shimamura 2000); inhibition, the ability to inhibit distracting information when selecting relevant information, or to attend selectively to one stream of information while discarding others (Baddeley 1996a; Kane and Engle 2000); shifting, the ability to suppress response strategies when shifting between different tasks (Miyake et al. 2000; Monsell 2003); and dual- task performance, the abili ty to perform in parallel two tasks that rely on different cognitive systems (see Baddeley et al. 1997; Logie and Della Sala 2001). Other types of executive processes that were not evaluated by Miyake (2000) have been suggested as separate cognitive entities. One of these is planning, the ability to organize behavior in relation to a specific goal (Owen 1997; Shallice 1982), and the other is the efficiency of access to long-term memory (Baddeley 1996b, 1998; Fisk and Sharp 2004). Acute administration of anticholinergic drugs has been shown to impair executive functions by many authors (Curran et al. 1991; Green et al. 2005; Rusted and Eaton-Williams 1991; Rusted 1988; Rusted et al. 1991; Rusted and Warburton 1988) but in these publications usually only one executive test was used, mostly with unknown loading on the different executive components discussed previously. These finding are therefore not comprehensive in examining the executive domains that are affected by cholinergic manipulations. Aside from studying anticholinergic effects in different executive components, in order to demonstrate that the cholinergic system is in fact directly responsible for executive effects it would be important to show that drugs which increase the availability of acetylcholine, or pro-cholinergics, have the opposite effects. To this end, we studied the modulatory role of the cholinergic system on the 6 different types of executive processes outlined above by investigating dose-dependent effects of acute oral doses (5 and 7.5 mg) of donepezil, a potent, specific, non-competitive inhibitor of acetylcholinesterase (Jann et al. 2002; Shigeta and Homma 2001) that increases the availability of acethylcholine. We administered acute doses to young healthy volunteers because neurologic/psychiatric disorders and aging (Gron et al. 2005), as well as chronic use (Poirier 2002; Tsukada et al. 2004), alter the status of the cholinergic system. To assess executive functioning we employed tests that have been shown to reflect each of these 6 separable processes. To evaluate updating, inhibition and switching we used tasks described by Miyake (2000) that showed high loading in the confirmatory factor analysis performed by these authors in each of these executive components. For dual-task performance we employed a standardized paradigm (Baddeley et al. 1997; Della Sala et al. 1995; Greene et al. 1995). For evaluating access to long-term memory we used word generation tasks (see Fisk et al. 2004), and for planning we selected the ecological Zoo Map Test (Wilson et al. 1996). We also evaluated arousal and sustained attention/vigilance changes that could interfere with executive measurements, in addition to performance on other working memory subsidiary components (see Baddeley 2007; Repovs and Baddeley 2006) that store visuospatial data (visuospatial sketchpad), phonological information (phonological loop), and integrated inform ation from different modalities, including activated long-term memory (episodic buffer). MATERIAL AND METHODS Participants: participants were 42 healthy native Portuguese speaking volunteers (aged 18 to 35) with body mass index between 20 and 25, with at least 12 years of schooling. They were non-smokers, in good physical and mental health as determined by medical history, scored within normal ranges in the Beck Depression Inventory and the State-Trait Anxiety Inventory (Gorenstein and Andrade 1996), and were on no psychotropic medication at the time of the study. Procedure: this was a randomized, double-blind, placebo-controlled, independent group-design study in which participants were randomly allocated to three acute oral treatments formulated in identical capsules (14 subjects each): placebo (glucose), donepezil 5 mg and donepezil 7.5 mg. The Ethics Committee of the institution (Universidade Federal de SÃ £o Paulo UNIFESP) approved the study protocol (project no. 0335/07) which was conducted in accordance with the Declaration of Helsinki. All subjects provided written informed consent and their IQ was estimated using the Ravens Progressive Matrices (Raven et al. 1988). On the day of the experiment participants were required to have a light breakfast after which they receive treatments. They were submitted to a test battery (see below) at 210 min. after treatments (close to peak-plasma concentration of donepezil: Jann et al. 2002) that lasted 1.5 h. with no prior training to insure that executive processing was involved (see Rabbitt 1997 ). Tests were presented in 4 randomly assigned orders, balanced between treatments. Test Battery Executive tasks Plus-minus task (Miyake et al. 2000): a measure of shifting that consisted of three lists of 30 two-digit numbers (the numbers 10-99 pre-randomized without replacement) on a single sheet of paper. On the first list, the participants were instructed to add 3 to each number and write down their answers. On the second list, they were instructed to subtract 3 from each number. Finally, on the third list, the participants were required to alternate between adding and subtracting 3 (i.e., add 3 to the first number, subtract 3 from the second number, and so on). List completion times, omission and comission errors were determined. The cost of shifting between the operations of addition and subtraction was then calculated as the difference between the time to complete the alternating list and the average times to complete the addition and subtraction lists. All the lists were performed under articulatory suppression (uttering the letter T) to prevent the use o phonological stratergies while the task was performed. Letter memory task (Miyake et al. 2000): a measure of updating in which several letters from a list were presented serially for 2000 ms per letter. The task was to recall the last 4 letters presented in the list. To ensure that the task involved continuous updating, the instructions required that participants rehearse out loud the last 4 letters by mentally adding the most recent letter and dropping the 5th letter back. For example, if the letters presented were T, H, G, B, S the participants should say, T . . . TH . . . THG . . . THGB . . . HGBS and answer HGBS at the end of the trial. The number of letters presented (5, 7, 9, or 11) varied randomly across trials to ensure that participants would continuously update their working memory representations until the end of each trial. After practicing on 2 trials with 5 and 7 letters, participants performed 12 trials for a total of 48 letters recalled, which took approximately 12 minutes. The dependent measure was the proportion of let ters recalled correctly in the right serial order. Stroop task (Stroop 1935): a test of inhibition that consists of a Word Colored Page, with common words printed in colors, and a Color-Word Page with names of colors printed in incongruent colors. The examinee must name the ink colors as quickly as possible. For each list the test yields two scores, the number of errors and the time necessary to complete the task. In addition, scores from the word colored page (which measures naming speed) are subtracted from those of the color-word page (naming with inhibition) to yield a score of the extra time needed for overriding the inconcruency of word name versus ink-color name. Dual-task paradigm (Baddeley 1997; Della Sala et al. 1995): evaluates dual-task performance. This is a paper and pencil test which involves a visuospatial tacking task (circle crossing) and a phonological/verbal one (digit span). The digit span task consists of the 90 sec. long repetition of digit sequences presented orally which the subject had to repeat in the proper order. Lists of increasing number of digits are read aloud at the rate of one digit per second and the participants are asked to repeat them in their order of presentation (forward digit span, which measures phonological loop functioning). Participants digit span was taken to be the maximum length at which subjects repeated correctly 5 of 6 sequences of digits. Spans or scores were the number of digits contained in the last sequence repeated correctly. The circle crossing task consists of traversing with an X a chain of 240 circles linked with arrows to form a path laid out on an A3-sized sheet of paper, which was pra cticed with a 240 circles path. Subjects are required to cross-out the circles as rapidly as possible for a period of 90 sec. The dual-task condition consists of the simultaneous execution of both tasks within a 90 sec period. To quantify participants performance we used the measure proposed by Baddeley et al. (1997), the mu index which expressed the overall percentage loss in the dual-tasks in relation to single tasks considering the contributions of both tasks to be of equal weight: mu = [1- (pm + pt)/2] x 100, where pm and pt were, respectively, the proportional phonological loss and visuospatial loss in the performance in the dual-task condition in relation to the single-task condition; pm equaled the number of correctly repeated digit sequences for the single-task (ps), and for the dual-task (pd), both divided by the total o sequences remembered (pm = ps pd); pt equalled the number of traversed circles for the single-task (ts) minus those traversed in the dual-task (td), divid ed by ts [pt = (ts td)/ts]. Zoo Map Test (Wilson et al. 1996): a task that measures planning abilities from the ecological Behavioural Assessment of the Dysexecutive Syndrome test battery (BADS). Participants are given a map of a zoo and a set of instructions relating to places they have to visit (e.g. elephant house, lion cage) and rules they must stick to (e.g. starting at the entrance and finishing at a designated picnic area, using designated paths in the zoo just once). There are two trials with identical aims that involve a visit to six out of the 12 possible locations. The first trial consists of a high demand version in which the planning abilities of the participants are rigorously tested. In the second, or low demand version, the participant is simply required to follow some instructions to reach specific locations. Scoring was based on the total number of errors in the high and low demand tasks, as well as the difference in time to conduct the high and low demand tasks [i.e. planning/thinking time a nd execution (drawing time) of the route in the high demand trials minus the drawing time in the low demand task (Allain et al. 2005)]. Word and letter fluency (Lezak 2004): to test access to long-term memory participants were told to orally generate as many words as possible that belonged to a given category and that began with a given letter in 2 minutes each. The participants were instructed not to use proper nouns or morphological variations of words and to void repetitions. Scores were the total number of words generated and errors. Executive digit span (modified from Della Sala et al. 1995): this task was the same as the digit span described above in the dual-task performance except that participants had to repeat the sequences backwards (backwards digit span). Spans or scores were the number of digits contained in the last sequence repeated correctly. A delta score (backward minus forward digit span) was also calculated because participants capacity to recall items backwards depends on their forward span. Other working memory test Corsi block test [computerized version based on Miyake et al. (2001)]: participants were shown a set of blocks (drawn as white boxes) and asked to remember the order in which they were tapped (shown as changing color). One box at a time turns black for 650 ms each, a duration short enough to discourage the use of idiosyncratic coding strategies. Five similar but different configurations of blocks were used in each trial to discourage participants from using numerical coding of box locations. Immediately after a sequence of taps, participants repeated the order (Corsi Block task direct, a measure of the visuospatial sketchpad) by clicking on the boxes with the mouse. Once the sequence of flashing boxes was completed, they had unlimited time to respond. There was a practice trial with two taps each, after which the sequences progresses in length from three to 10 taps or until the participants made two mistakes with a sequence of the same number of taps. Scores were the largest number of blocks recalled in the right sequence. The same procedure was conducted at the end of this task, except that subjects were asked to remember the taps in the inverse order (Backwards Corsi Block task, a general measure of executive functioning). Delta scores as calculated for digit span were also computed. Counting span [Conway et al. (2005) in the version designed for adults by Engle et al. (1999)]: a task of working memory capacity that evaluates storage in the episodic buffer component of working memory (see Baddeley 2007). Participants were presented with displays on screen which consisted of a random arrangement of three to nine dark blue circles, one to nine dark blue squares, and one to five light blue circles. The participants task was to count and remember, in the right serial order, the total number of dark blue circles presented in consecutive displays which varied randomly in number from 2 to 6 (3 sequences each). Scores were the number of correct sequences retrieved. Arousal/vigilance/visuomotor performance measures Psychomotor Vigilance Test (Dinges and Powell 1985): a portable device (Model PVT-192, CWE, Inc, Ardmore, PA) was used. The task consists of responding by button press to a small, bright red-light stimulus (light-emitting diode digital counter) as soon as it appears. Consecutive stimuli appear randomly in the range of 2 to 10 s for 5 minutes, resulting in 30-45 reaction time (RT) measures, depending on RT latency (Roach et al. 2006). Participants are instructed to press the button as soon as they see the stimulus, but not to press the button too soon (which yields false-start warnings on the display). Each subject was allowed a single 1-minute acclimation practice before the task commenced. Scores were mean total reaction time (RT), mean 10% fastest and slowest reaction times (Mean F RT and Mean S RT), all of which indicate arousal/psychomotor performance (Lim and Dinges 2008) and measures that indicate better sustained attention/vigilance (Lim and Dinges 2008), the percent change i n RT throughout the test (% change) and slope reaction time (negative numbers indicate slowing from the beginning to the end of the test). Statistical analysis To compare treatment groups we employed one-way analyses of variance (ANOVAs) with treatment as factor (3 levels: placebo, donepezil 5 mg and donepezil 7.5 mg) followed by post hoc Tukey HSD tests when appropriate. The level of significance adopted was pÃ ¢Ã¢â¬ °Ã ¤0.05. Only measures that elicited significant drug effects are reported below. Magnitude of effects on the executive measures was determined through effect size calculations (Cohen d, Cohen 1988) as proposed by Snyder et al. (2005) and Fredrickson et al. (2008). In addition we calculated the Pearson Product Moment correlation between changes in arousal/vigilance measured by the PVT and the variables that showed significant effects. RESULTS Comparability of treatment groups The ANOVAs showed the comparability of participants in the three treatment groups in terms of age, body mass index and estimated intelligence measured by Ravens Progressive Matrices (ps>0.27), so performance differences between treatments could not be accounted for by these characteristics. Treatment effects (Table 1) Data on PVT task of one subject in the placebo group and data on fluency test of one subject in the placebo group and of two subjects in donepezil 7.5 mg group were lost due to technical problems with the equipments. The ANOVAs showed PVT treatment effects for the minimum reaction time (F2,38=4.42, p [Table 1 and Figure 1 near here] Magnitude of effects Effect sizes (see Table 1) comparing placebo and 7.5 mg of donepezil were large (pÃ ¢Ã¢â¬ °Ã ¥0.8, see Cohen 1988; Sloan et al. 2005) for most of the PVT measures, as well as the delta score of the digit span. The remaining comparisons between these groups yielded medium effect sizes (between 0.5 and 0.8), that together with large effect sizes are considered meaningful differences (Cohen 1988; Sloan et al. 2005), and included the dual-task measure. Correlations between executive and other general attentional measures In order to determine whether arousal/vigilance/visuomotor changes were responsible for the observed executive effects, we calculated Pearson Product Moment correlations between the PVT measures and the executive measures that showed significant effects of donepezil (mu dual-task index and delta scores of the digit span). Correlation values were small and non-significant (all ps>0.05 and rs between -0.22 and 0.17). 5. Sample sizes In order to show that the sample size was adequate for this set of data we calculated the number of individuals necessary to show significant differences between placebo and the donepezil dose that showed significant differences in relation to placebo (7.5 mg). To do so we used the calculations proposed by Rosner (1999) [with an ÃÅ½Ã ± of 0.05 and 80% power]. This takes into account the mean values of the groups under comparison and their common standard deviation. We carried out these calculations considering one-sided differences since our hypothesis was that donepezil would increase performance (see table 1). DISCUSSION In the present study we completed a comprehensive examination of the potential capacity of a pro-cholinergic drug to improve executive functions in healthy young adults exploring diverse processes associated with executive tasks. Our findings extend previous reports on the acute nootropic potential of this drug in young, healthy volunteers (Hutchison et al. 2001; Thompson et al. 2000; Zaninotto et al. 2009). More specifically, an acute 7.5 mg dose of donepezil improved arousal/vigilance/visuomotor measures in addition to increasing performance especifically in the executive dual-task domain. An increment in delta digit span was also observed, a task that has unknown loading on the 6 executive components studies here. A role for acetylcholine in modulating executive function is consistent with earlier work reporting impairment after acute doses of the antimuscarinic scopolamine (Ellis et al. 2006; Green et al. 2005; Rusted et al. 1991a; Rusted 1988; Rusted and Warburton 1988; Thomas et al. 2008). However, in the present study we found this effect to be highly selective within the broad battery of executive domains. Only the dual-task domain measure was sensitive to the effects of donepezil while this drug left the remaining 5 tested executive domains unchanged. These evidences suggests cholinergic enhancement in the coordination of two tasks that rely on different cognitive systems, possibly due to activation of cortical cholinergic inputs which facilitate cognitive processes by increasing filtering of noise and distractors, which are necessary under taxing attentional conditions (Sarter et al. 2001). The magnitude of these positive changes reflected medium effect sizes which are treated as clinically meaningful (e.g. see Sloan et al. 2005) and that should be considered in light of the fact that the participants had optimum baseline performance having been young, highly educated, physically and mentally healthy, not deprived of sleep, food or otherwise compromised. The present result was not mediated by increases in speed of information processing, improvement in performance that relies in subsidiary working memory systems, nor task demands, as discussed below. This (see Logie and Della Sala 2001) lends support to the idea that the cholinergic system is involved in the executive process that coordinates different specialized functions when considered together with previous reports of scopolamine induced impairment of dual-task performance (Rusted and Warburton 1988). It is also noteworthy that patients with AlzheimerÃ ´s disease, which is in part characterized by cholinergic deficiency (Everitt and Robbins 1997), display particular problems in dual-task in comparison with single-task performance using the same (Baddeley et al. 1991; Greene et al. 1995; Kaschel et al. 2009) and different (MacPherson et al. 2007, see also Logie and Della Sala 2001) dual-task paradigms. Hence, we here obtained a pharmacological dissociation that confirms behaviou ral data suggesting the separability of dual-task coordination from other executive domains (e.g., Baddeley 1996b; Baddeley and Della Sala 1996; Bourke et al. 1996; Bourke 1997; Miyake et al. 2000; see also de Ribaupierre and Ludwig 2003). It could be argued that this was solely due to the lack of power of the study. Sample size calculations taking into account data from the placebo and donepezil 7.5 mg groups showed that the number of participants necessary for the obtention of statistical effects in the measures that were statistically significant here were close to that used in this study. However, the number of individuals in each group had to be larger than 66 to show significant effects in the remaining executive domains (Table 1). To our knowledge no study in this field of research has ever used such a large sample size. Hence, we believe that dual-task performance, among the executive domains investigated here, is particularly sensitive to improvement by increases in acetylcholine levels. On measures of general attention, donepezil improved (significantly with large effect sizes) sustained attention, arousal and visuomotor performance in the PVT, cognitive functioning measures that have been previously shown to be affected by cholinergic manipulations (Furey et al. 2000, 2008a; Meinke et al. 2006). These changes could in themselves have led to better executive performance, but this seems unlikely in the present case because better overall attention would not have benefited only this single executive component. In addition, no significant correlation was found between these general attentional scores and those of the executive tasks that were enhanced by donepezil, and r values were small. The changes in executive functioning found here could also not be ascribed to improvement in the subsidiary working memory systems which were unchanged by donepezil, in accordance with previous lack of effects with other acute cholinergic manipulations of the articulatory loop and visuospatial sketchpad (see Mintzer and Griffiths 2007; Rusted 1988; Zaninotto et al. 2009), as well as the episodic buffer (see Zaninotto et al. 2009). These changes could also not be attributed to task difficulty, as the letter memory task was at least as demanding as the dual-task. This latter task involved continuous updating of information of letter sequences, some of which extended way beyond subjects spans, for approximately 12 minutes, and showed no treatment effect. Performance in this task was unchanged by donepezil administration, but a similar n-back updating task has been shown to be impaired by acute doses of scopolamine (Green et al. 2005). In the latter case, though, the n-back task relied h eavily on visuospatial perception and processing, which seem particularly sensitive to cholinergic manipulations (Ellis and Nathan 2001; Thomas et al. 2008; Zaninotto et al. 2009). In retrospect we noted that none of the executive tasks used here made specific demands on this type of processing, neither did the executive inhibition task employed by Mintzer and Griffiths (2007), which was unaltered by acute scopolamine administration. In effect, Thomas (2008) suggested that visuomotor and working memory processes that subserve visuospatial executive function are specifically dependent on cholinergic neurotransmission. Hence, enhancement of cholinergic activity could cause specific top-down optimization of visuospatial input processing which could lead to improved executive visuospatial performance, especially if the extensive involvement of executive functions with visuospatial short-term memory is taken into account (see Miyake et al. 2001). Based on this suggestion it may be hypothesized that the improvement in the delta digit span measure obtained here (high effect size) and in a recent donepezil study (Zaninotto et al. 2009), as well as impairment after anticholinegic drugs (Guthrie et al. 2000) reflect effects of cholinergic manipulations because backward digit span seems to involves activation of occipital visual cortical areas (more so than the forward version of this test) in addition to prefrontal ones (see Sun et al. 2005). Therefore, a conjunction of executive attention and facilitated visual processing by donepezil may have led to the increase in performance in this task. Although we found cholinergic effects it is not possible to determine whether the present finding are due to the activation of nicotinic or muscarinic receptors because donepezil increases the amount of acetylcholine that can activate all acetylcholine receptors. Both types of receptors have been found to interact functionally, having synergistic effects particularly on visuospatial attention (Greenwood et al. 2009), working memory, and vigilance tasks (see Ellis et al. 2006; Erskine et al. 2004) so our data may reflect the effects of their combined activation. In sum, acute oral administration of 7.5 mg of donepezil to young, healthy volunteers had a selective positive effect in executive dual-task performance that was seemingly independent of the donepezil-induced improvement on broad attentional processes (arousal/visuomotor/vigilance) and working memory slave systems, corroborating the proposal that this type of executive processing constitutes a separable cognitive construct. In addition, improvement in the digit span delta scores points to the role of cholinergic modulation on other central executive measures, possibly those that rely more heavily in visuospatial processing.
Monday, August 19, 2019
Gilead: A Credible Society In Margaret Atwood's novel The Handmaid's Tale, a society whose purposes are functional and practical roles is depicted. In Atwood's eyes, a society like Gilead's was perfectly credible, and in many ways I agree with her. The purpose of writing about such a radical society is not for one to panic into thinking that this could happen any time, nor is it for one to completely discard the idea. Instead, it's purpose is solely to warn us of the dangers already present in our own society, such as the uncontrollable violence that is going on, apparent on crimes, wars, racism, etc. Offred, the narrator, tells us about a society which came into existence in the early 80's as a direct consequence of overlooking the many problems in its previous society. Before the first steps were being taken to actually destroy the society that few knew was already on the edge of becoming anarchical, there was foreshadowing of what would happen right beneath the eyes of everyone. Riots were going on all the time, people were vanishing, and later women lost their jobs and their money. All these things happened without people's objections, because they were simply ignoring it, possibly hoping that it could not get worst. As Offred later describes how they faced up to those problems, "We lived, as usual, by ignoring. Ignoring isn't the same as ignorance, you have to work at it" (74). This quote described what people did when they were fearsome of something, which they had already permitted to become the usual, bothered them. Ignoring what one fears makes that thing seem nor mal, and usually one becomes less afraid of things as they become normal. However, if things are ignored to an extreme and one does not care to draw the line, things can get out of hand when it is already too late. Offred regrets having been like the rest of the society that was banished, because looking back, what was happening then was in fact foreshadowing the future, Nothing changes instantaneously: in a gradually heating bathtub you'd be boiled to death before you knew it. There were stories in the newspapers, of course, corpses in ditches or the woods, bludgeoned to death or mutilated, . . . The newspaper stories were like dreams to us, bad dreams dreamt by others . . . they were awful without being believable. . . . they had a dimension that was no... ...illions of Americans crying out. Nor would it be possible that someone kill the president by simply entering his house. The problem is that these differences mean little when there are also many similarities. The purpose Atwood saw in her book is to warn us of our own dangers, not to compare them to a fictitious story and keep ignoring things. As I said before, I do not think we will ever have such an awful transformation in our lives, but I do not think something similar is impossible to occur. Because we are all being blind, like the other society was blind, and we ignore things like violence, we are building ourselves a path with no solid foundations. If we continue doing so, the tendency is for this path to fall apart. Even if this actually happened, it does not necessarily mean that we would have to give in to losing what is ours by all rights. Nevertheless, if we fall in a trend where everything is so casual that we ignore what is going on, something else could hap pen where we could forget to draw the limit and make it stop, as the society preceding Gilead did. WORKS CITED Atwood, Margaret. The Handmaid's Tale. 28th ed. New York: Ballantine Books, 1991. Gilead: A Credible Society Essay -- Essays Papers Gilead: A Credible Society In Margaret Atwood's novel The Handmaid's Tale, a society whose purposes are functional and practical roles is depicted. In Atwood's eyes, a society like Gilead's was perfectly credible, and in many ways I agree with her. The purpose of writing about such a radical society is not for one to panic into thinking that this could happen any time, nor is it for one to completely discard the idea. Instead, it's purpose is solely to warn us of the dangers already present in our own society, such as the uncontrollable violence that is going on, apparent on crimes, wars, racism, etc. Offred, the narrator, tells us about a society which came into existence in the early 80's as a direct consequence of overlooking the many problems in its previous society. Before the first steps were being taken to actually destroy the society that few knew was already on the edge of becoming anarchical, there was foreshadowing of what would happen right beneath the eyes of everyone. Riots were going on all the time, people were vanishing, and later women lost their jobs and their money. All these things happened without people's objections, because they were simply ignoring it, possibly hoping that it could not get worst. As Offred later describes how they faced up to those problems, "We lived, as usual, by ignoring. Ignoring isn't the same as ignorance, you have to work at it" (74). This quote described what people did when they were fearsome of something, which they had already permitted to become the usual, bothered them. Ignoring what one fears makes that thing seem nor mal, and usually one becomes less afraid of things as they become normal. However, if things are ignored to an extreme and one does not care to draw the line, things can get out of hand when it is already too late. Offred regrets having been like the rest of the society that was banished, because looking back, what was happening then was in fact foreshadowing the future, Nothing changes instantaneously: in a gradually heating bathtub you'd be boiled to death before you knew it. There were stories in the newspapers, of course, corpses in ditches or the woods, bludgeoned to death or mutilated, . . . The newspaper stories were like dreams to us, bad dreams dreamt by others . . . they were awful without being believable. . . . they had a dimension that was no... ...illions of Americans crying out. Nor would it be possible that someone kill the president by simply entering his house. The problem is that these differences mean little when there are also many similarities. The purpose Atwood saw in her book is to warn us of our own dangers, not to compare them to a fictitious story and keep ignoring things. As I said before, I do not think we will ever have such an awful transformation in our lives, but I do not think something similar is impossible to occur. Because we are all being blind, like the other society was blind, and we ignore things like violence, we are building ourselves a path with no solid foundations. If we continue doing so, the tendency is for this path to fall apart. Even if this actually happened, it does not necessarily mean that we would have to give in to losing what is ours by all rights. Nevertheless, if we fall in a trend where everything is so casual that we ignore what is going on, something else could hap pen where we could forget to draw the limit and make it stop, as the society preceding Gilead did. WORKS CITED Atwood, Margaret. The Handmaid's Tale. 28th ed. New York: Ballantine Books, 1991.
A former point-and-shoot photographer can take professional quality pictures with a digital SLR (single-lens reflex) camera by learning about and experimenting with its complex operations. There are many advantages to making the transition from a point-and-shoot digital camera to a digital SLR camera. These include capturing images Ã¢â¬Å"more quickly, more flexibly, and with more creativityÃ¢â¬ (Busch, Digital 9). Furthermore, taking photos with a digital SLR camera reduces the amount of time that otherwise would be spent editing with photo-editing software to improve the quality of the photos. Why would one want to switch from a point-and-shoot digital camera to a digital SLR camera? Some of the reasons are: a more accurate viewfinder, a more powerful sensor, less noise in the photos, depth-of-field control, speed, similarity to a regular SLR camera, more lens flexibility, and freedom from image editors (Rowse). Some disadvantages are: expense, size and weight, and complication of use. What are some of the key features to think about when purchasing a digital SLR camera? Some of the features are: lenses, sensors and image processors, exposure systems, and focusing systems. There are also special features to consider for the individual photographerÃ¢â¬â¢s needs (Busch, Digital 61-63). Lenses are one of the main items to consider when purchasing and using a digital SLR camera. All digital SLR cameras come with a basic general purpose (mid-range or normal) lens, but many people would rather have some specialty lenses, depending on the type of photography in which they are interested. Some of these specialty lenses are: zoom, prime, wide-angle, fish eye, telephoto, and macro. In addition, it is important to get a lens wit... ...35-40). One should take many pictures in different ways so that the ones offering the best composition can be chosen later. If the above suggestions are followed, quality photographs should be the result. However, the photographer may want to enhance the photos by using photo-editing software such as Adobe Photoshop, Corel Paint Shop Pro, Adobe Photoshop Elements, Picasa, Picnik, GIMP, or Adobe Photoshop Express. The last four programs are downloadable and free (Ã¢â¬Å"Photo Editing SoftwareÃ¢â¬ ). In conclusion, a former point-and-shoot photographer can make the transition to a digital SLR camera and take professional quality pictures by learning about and experimenting with the cameraÃ¢â¬â¢s complex features and operations. The first step is to purchase a digital SLR camera that suits the photographerÃ¢â¬â¢s needs. Then, one should start taking pictures - lots of them!