Do Sharks Ever Sleep, and How

Sharks need to keep water moving over their gills so that they receive oxygen. It was thought for a long time that sharks needed to move constantly in order to survive. This might mean that sharks couldnt stop, and therefore couldnt sleep. Is this true? Despite all the research on sharks over the years, shark sleep still seems to be a bit of a mystery. Explore the latest thoughts on whether sharks sleep.   True or False: a Shark Will Die If It Stops Moving Well, its sort of true. But also false. There are over 400 species of sharks. Some need to move pretty much all the time to keep water moving over their gills so that they can breathe. Some sharks have structures called spiracles  which allow them to breathe while they are lying on the ocean bottom. A spiracle is a  small opening behind each eye. This structure forces water across the shark’s gills so the shark can be still when it rests. This structure is handy for bottom-dwelling shark relatives like rays and skates, and sharks like ​wobbegong sharks, who ambush their prey by launching themselves off the ocean bottom when a fish passes by.   So Do Sharks Sleep? Well, the question of how sharks sleep depends on how you define sleep. According to the Merriam-Webster online dictionary, sleep is the natural periodic suspension of consciousness during which the powers of the body are restored.  Were not sure sharks are able to suspend their consciousness, although it may be possible. Do sharks curl up and rest for several hours at a time, like humans generally do? Thats not likely. Shark species that need to swim constantly to keep water moving over their gills seem to have active periods and restful periods, rather than undergoing deep sleep as we do. They seem to be â€Å"sleep swimming,† with parts of their brain being less active, or resting, while the shark remains swimming. At least one study has indicated that the sharks spinal cord, rather than the brain, coordinates swimming movements. This would make it possible for sharks to swim while they are essentially unconscious (fulfilling the suspending consciousness part of the dictionary definition), thus also resting their brain. Resting on the Bottom Sharks such as Caribbean reef sharks, nurse sharks, and lemon sharks have been seen lying on the ocean bottom and in caves, but they seem to continue to watch what is going on around them during this time, so its not definite that they are sleeping.   Yo-Yo Swimming ​Florida Program for Shark Research Director George H. Burgess discussed the lack of knowledge around shark sleep with the Van Winkles blog and says some sharks may rest during yo-yo swimming, when they actively swim to the surface but rest as they descend. Whether they actually rest or dream, and how resting varies among species, we dont really know.   However they actually get their rest, sharks, like other  marine animals, dont seem to fall into a deep sleep as we do. Sources Florida Museum of Natural History Department of Ichthyology.  Shark Grossman, J. 2015. How Do Sharks Sleep? Do They Dream? Van Winkles. Martin, R.A. How Do Sharks Swim When Asleep? ReefQuest Centre for Shark Research. Martin, R.A.  40 Winks Under the Sea.  ReefQuest Centre for Shark Research.

Harriet Tubm An Extraordinary Female Legend From The 1800s

Harriet Tubman Who is an extraordinary female legend from the 1800s? Who liberated herself from servitude? Who liberated other individuals from servitude? Not Wonder Woman, but rather Harriet Tubman. As you will see Harriet Tubman is a legend as seen through her own experience and lifetime achievements. I.Childhood Harriet Tubman was conceived Arminta Ross in 1820. She was conceived a slave in Bucktown, Maryland which is on the Eastern Shore. Her guardians were Harriet Green and Benjamin Ross. Her dad taught her all that he thought about the forested areas and this will help her later. She was nicknamed Minty before she began to pass by her mom s name Harriet. She had 10 siblings and sisters and her proprietor was Edward Brodas. She accepted that her family was a piece of the Ashanti tribe. All they needed to eat was cornmeal, smoked herring, and pork. They had no stove so all their nourishment was cooked outside. She began to work when she was five years of age. She was sold to James Cook to weave. That weaving made her hack and sniffle so she began viewing muskrat traps in the frigid stream. She got an extreme hack and a high fever. She was sent home to show signs of improvement. When she was seven she began to look after children. She stole a piece of sugar one day and was going to get whipped so she fled. When she returned she got whipped seriously. This is the point at which she figured out how to wear additional garments to cushion herself from the whip. She

The City Life and the Country Life Free Essays

Living area has always been a hotly discussed topic. Each person has their own preferences for staying in either a city, or the countryside. The typical differences between the city life and the country life will be soundly presented in this piece of paper. We will write a custom essay sample on The City Life and the Country Life or any similar topic only for you Order Now A city life differs from a country life in term of food and intellectual stimulation. To begin with, living in the city offers you various kinds of food. Cities are supposed to be the biggest food markets, therefore chefs do not have to travel far to get the oversea ingredients. Moreover, the city is certain to provide more facilities needed for intellectual stimulation than the countryside. Some of the major ones include modern technologies in universities, the diversity of books and magazines in libraries and bookstores, the enormous number of artworks in galleries and museums†¦ On the other hand, the country life contrasts with the city life regarding food and intellectual stimulation. Citizens in the countryside areas might not have a long list of foods, but they can guarantee that what they have been eating is totally safe because it is self-produced. More interestingly, many people consider the countryside an ideal place for educating a cultured person. Since it does not have as many amenities as the city, life in the country brings up more contemplative peace and quietness. One would have more time interact with himself, without being distracted by the outside elements as in a city. In brief, there are remarkable differences in food and intellectual stimulation between a city life and a country life. I highly recommend that you should consider my essay to make an appropriate decision on which area is the most suitable for yourself. How to cite The City Life and the Country Life, Essay examples

Social, Political And Economic Effects Of WWII Essay Example For Students

Social, Political And Economic Effects Of WWII Essay Everywhere in the world was heard the sound of things breaking. Advanced European societies could not support long wars or so many thought prior to World War I. They were right in a way. The societies could not support a long war unchanged. The First World War left no aspect of European civilization untouched as pre-war governments were transformed to fight total war. The war metamorphed Europe socially, politicaly, economically, and intellectualy. European countries channeled all of their resources into total war which resulted in enormous social change. The result of working together for a common goal seemed to be unifying European societies. Death knocked down all barriers between people. All belligerents had enacted some form of a selective service which levelled classes in many ways. Wartime scarcities made luxury an impossibility and unfavorable. Reflecting this, clothing became uniform and utilitarian. Europeans would never again dress in fancy, elaborate costumes. Uniforms led the way in clothing change. The bright blue-and-red prewar French infantry uniforms had been changed after the first few months of the war, since they made whoever wore them into excellent targets for machine guns. Womens skirts rose above the ankle permanently and women became more of a part of society than ever. They undertook a variety of jobs previously held by men. They were now a part of clerical, secretarial work, and te! aching. They were also more widely employed in industrial jobs. By 1918, 37. 6 percent of the work force in the Krupp armaments firm in Germany was female. In England the proportion of women works rose strikingly in public transport (for example, from 18,000 to 117,000 bus conductors), banking (9,500 to 63,700), and commerce (505,000 to 934,000). Many restrictions on women disappeared during the war. It became acceptable for young, employed, single middle-class women to have their own apartments, to go out without chaperones, and to smoke in public. It was only a matter of time before women received the right to vote in many belligerent countries. Strong forces were shaping the power and legal status of labor unions, too. The right of workers to organize was relatively new, about half a century. Employers fought to keep union organizers out of their plants and armed force was often used against striking workers. The universal rallying of workers towards their flag at the beginning of the war led to wider acceptance of unions. It was more of a bureaucratic route than a parliamentary route that integrated organized labor into government, however. A long war was not possible without complete cooperation of the workers with respect to putting in longers hours and increasing productivity. Strike activity had reached its highest levels in history just before the war. There had been over 1,500 diffent work stoppages in France and 3,000 in Germany during 1910. More than a million British workers stopped at one time or another in 1912. In Britain, France, and Germany, deals were struck between unions and government to eliminate strikes and less favorable work conditions in exchange for immediate integration into the government process. This integration was at the cost of having to act more as managers of labor than as the voice of the labor. Suddenly, the strikes stopped during the first year of the war. Soon the enthusiasm died down, though. The revival of strike activity in 1916 shows that the social peace was already wearing thin. Work stoppages and the number of people on strike in France quadrupled in 1916 compared to 1915. In Germany, in May 1916, 50,000 Berlin works held a three-day walkout to protest the arrest of the pacifist Karl Liebknecht. By the end of the war most had rejected the government offer of being integrated in the beaurocracy, but not without playing an important public role and gaining some advantages such as collective bargaining. The war may have had a leveling effect in many ways, but it also sharpened some social differences and conflicts. Soldiers were revolting just like workers: They were no longer willing to sacrifice their lives when shirkers at home were earning all the money, tkaing, the women around in cars, cornering all the best jobs, and while so many profiteers were waxing rich. The draft was not completely fair since ot all men were sent to the trenches. Skilled workers were more important to industry and some could secure safe assignments at home. Karl marx 5 EssayUnskilled workers and workers in less important industries fell behind. Clerks, lesser civil servants, teachers, clergymen, and small shopkeepers earned less than many skilled labors. Those who suffered the most were those dependent on fixed incoming. The incomes of old people on pensions or middle class living on small dividends remained about the same while prices double or tripled. These dropped down into poverty. These new poor kept their pride by repairing old clothes, supplementing food budget with gardens, and giving up everything to appear as they had before the war. Inflation radically change the relative position of many in society. Conflicts arose over the differences in purchasing power. All wage earners had less real purchasing power at the end of the war than they had had at the beginning. To make matters worse some great fortunes were built during the wartime and postwar inflation. Those who were able to borrow large amounts of money could repay their debts in devalued currency from their war profit. Four years of chaos and utter destruction had smashed the old world Europe. The most advanced quarter of the world had turned to violence and barbarism of its own accord. Progress and reason had been suppressed for destruction. Moreover, it has brought to light an almost incredible phenomenon: the civilized nations know and understand one another so little that one can turn against the other with hate and loathing. Indeed, one of the great civilized nations is so universally unpopular that the attempt can actually be made to exclude it from the civilized community as barbaric, although it has long proved its fitness by the magnificent contributions to that community which it has made. The early part of the war satisfied the fascination with speed, violence, and the machine as manifested in the pre-war Futurists. Many movements shared a resolute modernist contempt for all academic styles in the arts, a hatred for bourgeois culture, and a commitment to the free expression of individuals. All these feelings were given an additional jolt of violence and anger by the horrors of the wartime experience. During the war there was a loss of illusions as described in All Quiet on the Western Front. Poets, like others, had gone to war in 1914 believing in heroism and nobility. Trench warfare hardened and embittered many. Freud said of disillusionment: When I speak of disillusionment, everyone will know at once what i mean. One need not be a sentimentalist; one may perceive the biological and psychological necessity for surrering in the economy of human life, and yet condemn war both in its means and ends and long for the cessation of all wars. British poet, Wilfred Own, who was killed in 1918 was transformed from a young romantic into a powerful denouncer of those who had sent young men off to war. In Dulce et Decorum Est he mocked the old lie that it was good to die for ones country, after giving a searing description of a gassed soldier coughing out his lungs. The anger of the soldier-poets was directed against those who had sent them to the war, not their enemy. The war experience did not produce new art forms or styles. It acted largely to make the harshest themes and the grimmest or most mocking forms of expression of prewar intellectual life seem more appropriate, and to fost experiments in opposition to the dominant values of contemporary europe. The Dada movement, which mocked old values and ridiculed stuffy bourgeois culture, was one of these movements. A mood of desolation and emptiness prevailed at the end of a war where great sacrifice had brought little gain. It was not clear where post-war anger would be focused, but it would definately be in antibourgeois politics. The echoes of a world shattering were heard throughout the world as Europe collapsed into total war. These echoes were the sound of change as Europe was transformed socially, politicaly, economically, and intellectualy into a machine of complete destruction. Europe would never be the same again.