How Sleep Helps the Brain Clean Itself

How Sleep Helps the Brain Clean Itself Sleep and Dreaming Print Sleeping Helps to Clean the Brain By Kendra Cherry facebook twitter Kendra Cherry, MS, is an author, educational consultant, and speaker focused on helping students learn about psychology. Learn about our editorial policy Kendra Cherry Medically reviewed by Medically reviewed by Sanja Jelic, MD on October 30, 2019 Sanja Jelic, MD, is board-certified in sleep medicine, critical care medicine, pulmonary disease, and internal medicine.   Learn about our Medical Review Board Sanja Jelic, MD Updated on January 04, 2020 Westend61 / Getty Images More in Psychology Sleep and Dreaming Psychotherapy Basics Student Resources History and Biographies Theories Phobias Emotions The exact reason why we sleep has long been one of the greatest mysteries of modern science. Many different theories have been proposed, but the fact is that no one is entirely sure why we spend roughly a third of our lives asleep. There has been a great deal of research showing how sleep helps consolidate memories and repair the body, yet many scientists believe that these actions do not fully explain the underlying purpose of sleep, particularly from an evolutionary standpoint. Spending so much of our lives asleep and vulnerable opens us up to great danger, so many experts believe there must be a more compelling reason why we sleep. One of the top theories of sleep suggests that slumber is necessary to allow the brain to clean up and reboot from the previous day’s activities. Research in mice supports this theory. A study published in a 2013 issue of the journal Science revealed that sleep gives the brain a chance to clean itself. The study itself involved looking at the flow of fluids in the brains of mice in awake and sleep states. The researchers focused in particular on how fluids flow within the lymphatic system or the spaces between neurons. This is something like a waste disposal system, clearing out the waste products that brain cells generate when performing normal tasks. Fluid Flow Increases in Sleeping Brains However, transporting these waste materials requires a great deal of energy, and the researchers hypothesized that the brain would not be able to support these cleaning functions and process sensory information at the same time. To test this idea, the studys lead author, Lulu Xie, spent two years training mice to fall asleep on a type of microscope that would allow the researchers to observe dye moving through living tissue. After EEG activity confirmed that the mice were really asleep, a green dye was injected into their cerebrospinal fluid. A half-hour later the mice were awakened and a red dye was then injected. Through this process, the researchers were able to watch the movements of the green and red dye through the brain. What they observed was that while large amounts of cerebrospinal fluid flowed through the brain during sleep, the very little movement was observed while awake. Spaces Between Brain Cells Become Larger During Sleep So why was there such greater fluid flow during the sleeping states as opposed to the awake states? The researchers also observed that the interstitial spaces between brain cells became much larger during sleep, allowing fluid to flow more freely. These channels increased by approximately 60% during sleep. The researchers also found when certain proteins were injected into the mice, the proteins were cleared away much more quickly during sleep.   Possible Implications “These findings have significant implications for treating ‘dirty brain’ disease like Alzheimer’s,” said Maiken Nedergaard, one of the study’s authors.  â€œUnderstanding precisely how and when the brain activates the glymphatic system and clears waste is a critical first step in efforts to potentially modulate this system and make it work more efficiently.” Scientists have long known that certain neurological conditions such as dementia, Alzheimers, and stroke are all associated with sleep disturbances. According to Nedergaard, these results might suggest that lack of sleep could play a causal role in such conditions. Now that the researchers have identified this brain-cleaning process, their hope is that it will lead to further research on how the process works and the possible role it might play in neurological conditions such as Alzheimers disease. The study also once again underscores the importance of sleep. This could open a lot of debate for shift workers, who work during the nighttime,” Nedergaard told Science. You probably develop damage if you don’t get your sleep.

The Importance Of A Project Management System - 2950 Words

Executive Summary The following report is aimed at exploring the importance of a project management system and its role in determining the final outcome of a project. The report will allow the reader to understand the reasons that attribute to the success and also the failure of a project. Most projects are considered a failure although the final objective is accomplished as they are not able to adhere to the fundamental factors of cost, quality and time. The reasons for this are highlighted in the report and the author provides some tools and techniques that can be used in project management to facilitate project success. Some of the limitations of this research are discussed and the author provides recommendations that can be used to add†¦show more content†¦The research includes an in-depth analysis of Work Breakdown Structure, Critical Path Analysis and Systems thinking as the tools to be used with the project management system. 2.0 Scope of Literature Review This report was compiled through the study of peer reviewed articles from the following databases and journals dated 2007 and after. Databases: Elsevier ScienceDirect, EBSCOhost, ProQuest, Taylor Francis, DOAJ Directory Journals: International Journal of Project Management International Journal of Information Technology and Decision Making IEEE Software Applied Mathematical Modelling International Journal of Production Research Chemical Engineering Decision Support Systems Tooling and Production Journal of Software Communications of the IBIMA Automation in Construction Evaluation and Program Planning Issues in Informing Science and Information Technology 3.0 Project Management In the current world of strategic competitiveness, organizations have begun using Project Management as a tool or method to increase productivity. Managers are being encouraged to use Project Management systems over the traditional functional management systems due to its effectiveness and the achievement of multiple benefits (Mir and Pinnington 2014, 202). According to Attarzadeh and Ow (2008, 234), project management

Course Article - 8941 Words

Parting at the Crossroads: The Development of Health Insurance in Canada and the United States, 1940-1965 Author(s): Antonia Maioni Source: Comparative Politics, Vol. 29, No. 4 (Jul., 1997), pp. 411-431 Published by: Ph.D. Program in Political Science of the City University of New York Stable URL: http://www.jstor.org/stable/422012 . Accessed: 12/10/2013 14:05 Your use of the JSTOR archive indicates your acceptance of the Terms Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to†¦show more content†¦I argue that the federal structureand parliamentary institutionsof the Canadianpolitical system encouragedthe formationof a social democraticthirdpartyand enhancedits efficacy in promotinghealthpolicy reform. The institutionalconstraintsof the Americanpolitical system, in contrast,impeded and the emergenceand consolidationof this type of policy entrepreneur forced the proponentsof health reformto restraintheir strategiesin orderto appeal to a wider coalition within the Democratic party.8The research methodology used in this article is based on comparativehistorical analysis, which involves examining the historical evidence for causal regularities and evaluating different explanatory factors that can account for divergent paths to social reform.9Here, I trace the postwar development of health reform in Canada and the United States, on concentrating the quarter centurybetween 1940 and 1965 when the two countries parted in their approachtoward health reform. The significant difference, as the historical evidence suggests, is the presence of a social democraticthird party in Canada able to influence the trajectory of health reform that resulted in the implementationof public, universalhealth insurance. Institutions, Parties, and Health Reform Institutional arrangementshave been identified as among the most important constraintsstill faced by health reformersin the United States. oStill, the linkagesShow MoreRelatedWell Educated Essay1288 Words   |  6 PagesNarrative Essay 1 - Well Educated Eng. 101 Liberty Online Professor Well Educated We all more than likely know someone who would fit the common catch phrase of being very well educated but having absolutely no common sense .Alfie Kohn’s article â€Å"What does it mean to be well educated?† elaborated on this topic wonderfully. Moreover, Kohn added, familiarity with lists of words, names, books and ideas is a poor way of judging whether one is well-educated. 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Mediatory Argument Free Essays

When it comes to finding common ground on important issues, few polarize people as much as immigration questions and difficulties. There are plenty of varying opinions on immigration, especially when one considers whether or not to grant United States citizenship to illegal immigrants. Some feel that illegal immigrants should be given a chance to earn their citizenship, since they are already in the country. We will write a custom essay sample on Mediatory Argument or any similar topic only for you Order Now Others feel that they are criminals who deserve nothing from the government of the United States. Finding a middle ground on that issue is difficult, but it is possible through mediation. When one takes the time to research the issue at hand, some interesting things come to light. The first thing that a person must understand is the definition of an illegal alien. An illegal alien, as the name suggests, is a person who comes to the United States illegally. In short, it is a person that enters the country through some means that is not approved by the immigration office of the United States. The punishment for such an offense is something that must also be considered by any person who is looking to do research. If an illegal alien is found out in the United States, then they are usually deported back to the country where they came from. In some cases, they are detained for a short time before being shipped back to their country. Research must also be done on the options for these people. Where do they come from and why do they come to the United States? As one might expect, the majority of illegal aliens come to the United States because they have nowhere else to go. These people do not have a future or a leg to stand on in their previous countries, so they make their way into America with an eye on making a new life for themselves or for their families. One side of this argument might also focus on the job status of these people, as well. Unfortunately for many Americans, some of the jobs have been occupied by illegal aliens. This is something worth considering if one hopes to find a middle ground between the two sides of this equation. There are certain middle grounds in this argument where people come together. Though folks might disagree on many things, one would be hard pressed to find anyone who believed that illegal aliens were worse off in the United States. In addition, most people on either side of the chart can admit that illegal aliens are just as likely to pass the citizenship requirements as those people who migrate to the United States legally. In addition to all of that, both sides can see some part of the American dream coming out in this situation. When America was being formed, it took on all comers as a place where anyone could come to explore and find great opportunities. Though that has changed some, it is still one of the American ideals that all residents of this country hold near and dear. As for disagreements, there are many in this case. The fundamental disagreement between the two sides is that people who think illegal immigrants should be given citizenship believe that the illegal alien laws are unfair. They believe that there needs to be widespread reform to accommodate for those people who make their way to the United States. Their basic argument is that it should not be illegal to come to America. Those on the other side would argue that the laws are in place to protect the country from being overrun by cheap labor and they are there to keep the economy in tact. In addition to all of that, the two sides disagree on the impact that illegal immigrants might have on the job market. Those who support the illegal immigrants feel that, ultimately, the increased productivity with these new workers will help stimulate the economy. Obviously, those on the other side feel that adding more low cost workers will make it difficult for people to demand competitive wagers in a competitive market. It is important to keep in mind the different viewpoints when trying to reach a common ground. In this case, the perspectives could not be any different on the issue. On one side, there are the illegal immigrants, who have escaped their previous life and made it to the land of opportunity. They see a new life sitting right in front of them for the taking and they see nothing wrong with that. Those who want these people gone are looking out for their best interests and they are somewhat fearful of what could happen is illegal immigrants were granted citizenship. Because neither party has had the chance to walk in the other party’s shoes, it makes things especially difficult. Illegal immigrants cannot understand why those people in the U.S. do not want to share their wealth. Those in the U.S. do not understand where the illegal immigrants have come from and why they might have made the decision to come. The common ground here is that everyone wants to work for the greater good of the human race. While it might seem like an idealistic or simplistic common ground, it is the basic premise that will have to drive the decision making. No good intentioned human being wants to see another human being suffer. That is where these people can come together. There are plenty of people in the United States who would want to see illegal immigrants exported that might have come from a rough background. They can certainly relate to the plight of these immigrants. The common ground is not a huge piece of dirt, but there is room for people to come together there for the great good of society. As far as a solution goes, there seems to be a place for one in this case. Though it might not fall right in the middle of what people are looking for, there is a way to come to something of a compromise. In order to give illegal immigrants the best chance to prove themselves and earn their way into the country, a probationary period must be adhered to before they are â€Å"full citizens†. In addition to that, they would have to complete all of the steps that normal immigrants have to go through, including the tests. This would benefit both sides, as it would not blindly throw people back into the hell that they used to inhabit, but it also would not open up the borders to anyone who wanted to come. Those people who made the choice to come to America would understand that it is going to take a long time to gain citizenship. In addition, this might even encourage people to go about immigration the right way, instead of having to sneak into the country. How to cite Mediatory Argument, Essay examples

Television Fundementals Essays - Television Technology,

Television Fundementals In this report on television I will discuss television signals, the components the make up a television, and how a television produces the picture and sound for the final output. The sound carrier is at the upper end of the spectrum. Frequency modulation is used to impress the sound on the carrier. The maximum frequency deviation is twenty-five kilohertz, considerably less than the deviation permitted by confessional FM stereo. As a result, a TV sound signal occupies less bandwidth in the spectrum than a standard FM broadcast station. Stereo sound is available in TV, and the multiplexing method used to transmit two channels of sound information is virtually identical to that used in stereo transmission for FM broadcasting. The picture information is transmitted on a separate carrier located 4.5 MHz lower in frequency than the sound carrier. The video signal derived from a camera is used to amplitude modulate the picture carrier. Different methods of modulation are used for both sound and picture information so that there is less interference between the picture and sound signals. The full upper sidebands of the picture information are transmitted, but only a portion of the lower sidebands is suppressed to conserve spectrum space. The color information in a picture is transmitted by way of frequency division multiplexing techniques. Two color signals derived from the camera are used to modulate a subcarrier that, in turn, modulates the picture carrier along with the main voice information. The color subcarriers use double-sideband-suppressed carrier AM. The video signal can contain frequency components up to 4.2 MHz. Therefore, if both sidebands were transmitted simultaneously, the picture signal would occupy 8.4 MHz. The vestigal sideband transmission reduces this excessive bandwidth. Because a TV signal occupies so much bandwidth, it must be transmitted in a very high frequency portion of the spectrum. TV signals are assigned to frequencies in the VHF and UHF range. United States TV stations use the frequencies between 54 and 806 MHz. This portion of the spectrum is divided into sixty-eight 6MHz channels that are assigned frequencies. Channels 2 through 7 occupy the frequency range from 54 to 88 MHz. Additional TV channels occupy the space between 470 and 806 MHz. The video signal is most often generated by a TV camera, a very sophisticated electronic device that incorporates lenses and light-sensitive tranducers to convert the scene or object to be viewed into an electrical signal that can be used to modulate a carrier. To do this, the scene to be transmitted is collected and focused by a lens upon a light-sensitive imaging device. Both vacume tube and semiconductor devices are used for converting the light information in the scene into an electrical signal. The scene is divided into smaller segments that can be transmitted serially over a period of time. It is the job of the camera to subdivide the scene in an orderly manner so that an acceptable signal is developed. This process is called scanning. Scanning is a technique that divides a rectangular scene up into individual lines. The standard TV scene dimensions have an aspect ratio of 4:3; that is, the scene width is four units for every 3 units of height. To create a picture, the scene is subdivided into many fine horizontal lines called scan lines. Each line represents a very narrow portion of light variations in the scene. The greater the number of scan lines, the higher the resolution and the greater the detail that can be observed. United States TV standards call for the scene to be divided into a maximum of 525 horizontal lines. The task of the TV camera is to convert the scene into an electrical signal. The camera accomplishes this by transmitting a voltage of 1 volt for black and 0 volts for white. The scene is divided into 15 scan lines numbered 0 through 14. The scene is focused on the light-sensitive area of a vidicon tube or CCD imaging device that scans the scene one line at time, transmitting the light variations along the lines as voltage levels. Where the white background is being scanned a 0 volt signal occurs. When a black picture element is encountered a 1 volt level is transmitted. The electrical signals derived from each scan line are refereed to as the video signal. They are transmitted serially one after the other until the entire scene has been sent. Since the scene contains colors, there are different levels of light along each scan line. This information is transmitted as different shades of gray between black and white.

The Roles of Queens, Drones and Worker Honey Bees

The Roles of Queens, Drones and Worker Honey Bees Honey bees are social creatures that enlist a caste system to accomplish the tasks that ensure the survival of the colony. Thousands of worker bees, all sterile females, assume responsibility for feeding, cleaning, nursing, and defending the group. Male drones live to mate with the queen, who is the only fertile female in the colony.   The Queen The queen bee is the dominant,  adult female bee that is the mother of most, if not all the bees in the hive. A future queen bees larva is selected by worker bees to be nourished with a protein-rich secretion known as royal  jelly so that it can sexually mature.   A newly hatched queen begins her life in a duel to the death with any other queens present in the colony and must destroy potential rivals that have not yet hatched. Once she accomplishes this, she takes her virgin mating flight. Throughout her life, she lays eggs and secretes a pheromone that keeps all other females in the colony sterile. Drones A drone is a male bee that is the product of an unfertilized egg. Drones have bigger eyes and lack stingers. They cannot help defend the hive and they  do not have the body parts to collect pollen or nectar, so they cannot contribute to feeding the community. The drones only job is to mate with the queen. Mating occurs in flight, which accounts for the need of the drones for better vision, which is provided by their large eyes. Should a drone succeed in mating, he soon dies because the penis and associated abdominal tissues are ripped from the drones body after sexual intercourse. In the fall in areas with colder winters, worker bees mind the food stores and prevent drones from entering the hive since they are no longer needed, effectively starving them to death. Workers Worker bees are female. They accomplish every chore unrelated to reproduction, which is left up to the queen bee. In their first days, workers tend to the queen. For the remainder of their short lives (just a single month), workers keep busy. Newly hatched worker bees are larvae, unable to feed themselves. Worker bees feed their larvae a liquid called worker jelly, and they eat as many as 800 times a day to build up fat stores. After eight or nine days, larval worker bees spin cocoons and enter the pupal stage. Three weeks later, fully-formed worker bees chew through their cocoons; just a few hours later theyre ready to go to work. There are many jobs for workers to do, such as preserving  honey, feeding drones, building the honeycomb, storing pollen, removing the dead, foraging for food and nectar, carrying in water, fanning the hive to maintain the proper temperature, and guarding the hive against invaders such as wasps. Worker bees also make the decision, when necessary, to relocate the colony in a swarm  and then rebuild the new nest. Maintaining proper temperature for the hive is crucial for the survival of the eggs and larvae. The brood chamber for the bees young must remain at a steady temperature to incubate the eggs. If it is too hot, the workers collect water and deposit it around the hive, then fan the air with their wings causing cooling by evaporation. If it is too cold, the worker bees cluster to generate body heat.

Definition and Examples of Derivation in English

Definition and Examples of Derivation in English In morphology, derivation is the process of creating a new word out of an old word, usually by adding a prefix or a suffix. Adjective: derivational. Linguist Geert Booij notes that one criterion for distinguishing derivation and ​inflection is that derivation may feed inflection, but not vice versa. Derivation applies to the stem-forms of words, without their inflectional endings, and creates new, more complex stems to which inflectional rules can be applied (The Grammar of Words, 2005).   Derivational change that takes place without the addition of a bound morpheme (such as the use of the noun impact as a verb) is called zero derivation or conversion. From the Latin, to draw off. Examples and Observations Derivational morphology studies the principles governing the construction of new words, without reference to the specific grammatical role a word might play in a sentence. In the formation of drinkable from drink, or disinfect from infect, for example, we see the formation of new words, each with its own grammatical properties.(David Crystal, How Language Works. Overlook Press, 2005 Derivation versus Inflection Morphology may be divided into derivationrules that form a new word out of old words, like duckfeathers and unkissableand inflectionrules that modify a word to fit its role in a sentence, what language teachers call conjugation and declension. (Steven Pinker, Words and Rules: The Ingredients of Language. Basic Books, 1999)The distinction between inflectional morphology and derivational morphology is an ancient one. Fundamentally, it is a matter of the means used to create new lexemes (derivational affixes among other processes) and those used to mark the role of the lexeme in a particular sentence (accidence, inflectional morphology). . . .It seems that although we probably can maintain a distinction between inflectional and derivational morphology relatively well in Englishalbeit with certain problematical cases which do not invalidate the fundamental notionthe distinction is not helpful to us in understanding any other aspects of the morphology of English. The classification might be useful in terms of typology, but does not throw much light on the behavior of English morphological processes.(Laurie Bauer, Rochelle Lieber, and Ingo Plag, The Oxford Reference Guide to English Morphology. Oxford University Press, 2013 Derivation, Compounding, and Productivity Word-formation is traditionally divided into two kinds: derivation and compounding. Whereas in compounding the constituents of a word are themselves lexemes, this is not the case in derivation. For instance, -ity is not a lexeme, and hence taxability is a case of derivation. The word income tax, on the other hand, is a compound since both income and tax are lexemes. Changing the word class of a word, as happened in the creation of the verb to tax from the noun tax, is called conversion, and may be subsumed under derivation. . . .Morphological patterns that can be systematically extended are called productive. The derivation of nouns ending in -er from verbs is productive in English, but the derivation of nouns in -th from adjectives is not: it is hard to expand the set of words of this type such as depth, health, length, strength, and wealth. Marchand (1969: 349) has observed some occasional coinings like coolth (after warmth)  but notes that such word coinings are often jocular, a nd hence do not represent a productive pattern. If we want to coin a new English noun on the basis of an adjective, we have to use -ness or -ity instead. (Geert Booij, The Grammar of Words: An Introduction to Linguistic Morphology. Oxford University Press, 2005 Changes to Meaning and Word Class: Prefixes and Suffixes Derivational prefixes do not normally alter the word class of the base word; that is, a prefix is added to a noun to form a new noun with a different meaning:Derivational suffixes, on the other hand, usually change both the meaning and the word class; that is, a suffix is often added to a verb or adjective to form a new noun with a different meaning: patient: outpatientgroup: subgrouptrial: retrialadjectivedark: darknessverbagree: agreementnounfriend: friendship (Douglas Biber, Susan Conrad, and Geoffrey Leech,  Longman Student Grammar of Spoken and Written English. Longman, 2002)