Role of education leaders Essay Example | Topics and Well Written Essays - 500 words

Role of education leaders - Essay Example The main functions of the school district are to employ teachers and take corrective actions, solve disciplinary matters and taxation. Maryland is an exception in this case. All schools are controlled by the county. In general, it is possible to distinguish the following forms of control: (1) school district governments; (2) state-dependent school systems; (3) local-dependent school systems and (4) education service agencies (Dembowski 1999). Educational standards and practices are the engine driving the changes public schools are experiencing today. These bodies control schools and establish education standards and procedures. The school district provides qualified teachers, adequate instructional materials, and sound facilities. As such standards for opportunity to learn are articulated, the accountability question arises as to how to monitor and report on them. The school district articulates a means of observation in schools and classrooms in order to determine the degree of adherence to these standards (Sergiovanni et al 2003). Two aspects of this must be considered: the quality of individual teachers and the quality of the school as a whole. The control is exercised through school review process.

Astronomy Essay Example | Topics and Well Written Essays - 750 words - 2

Astronomy - Essay Example b. what is the significance or importance of patterns or cycles in nature to the development of science? Patterns or cycles help science by predicting behavior of seasons, planet movement, and other aspects of our environment. The prediction of these seasons were vital to the survival of ancient people, and still help farmers today. Without these predictions humans would have no food. Astronomy helped ancient civilizations predict the seasons, create temples, invent astronomy and even create gods out of the sky. The practical uses were the making of a calendar to predict seasons. This helped with harvesting food, plan for harsh climates, and gave ancient civilizations a way to document time. 5. describe the apparent motions of the planets in the sky. The planets seem to have the apparent motions of back and forth depending on their orbit and the earth’s position. This proves that all the planets have their own orbits around the sun. 7. how did kepler first try to relate the spacing of the orbits of the planets? Why did kepler find this approach philosophically satisfying? Kepler felt that the spacing of the planet orbits was spiritual. The universe was built in God’s image. The sun was God the Father, the Earth the Son, and everything in between the Holy Spirit. Kepler felt science and religion could compliment each other. On February 4, 1600, Kepler met Tycho Brahe at Benà ¡tky nad Jizerou in Poland. This is where Tychos new observatory was being constructed. This observatory was for Tycho’s studies on Mars. Kepler’s political and religious troubles in Poland plagued the mutual work of Kepler and Tycho. "Since the divine benevolence has vouchsafed us Tycho Brahe, a most diligent observer, from whose observations the 8 error in this Ptolemaic computation is shown, it is fitting that we with thankful mind both acknowledge and honor this benefit of God... For if I had thought I could ignore

Buying a House in Todays Economy Essay Example for Free

Buying a House in Todays Economy Essay The economy can make or break many decisions and on buying a house is a major one to make sure that the economy is in a good state that buying a house is not the right decision. When it comes to the marginal benefit the economy should be at an increase because purchasing the house is not anything that needs to be done but it is something that one wants to do and if the economy is bad then there is not any money available to make the extra purchase of buying a home at that time. Marginal ost in purchasing a house can affect economy by the simple fact of saving money here and there on some things in order to make sure that that they have money available to buy the house. The selling of the products they might have bought will decrease the economies profits. The removal of tax deduction on the mortgage interest affects the housing market because it will cause people to not be buying houses because some see the tax as a cushion for them to be able to get a house that they may not have had a chance to et based on their income. If they do not have a feeling of safety in purchasing a home they will not take the chance. The ways that government spends money on other things and the taxes make a decision a bit harder because a person Just wants to make sure that buying the house will not result in not having any money to do anything else. If the government ends up spending money on things not needed then there will not be enough money in banks and other finance resources that can help a person purchase a home.

Theory of electromyography

Theory of electromyography Theory of Electromyography Electromyography is a discipline that deals with the detection, analysis and use of electrical signal that emanates from skeletal muscles. The electromyography is studied for various reasons in the medical field. Even a superficial acquaintance with scientific literature will uncover various current applications in fields such as neuro physiology, kinesiology, motor control, psychology, rehabilitation, medicine and biomedical engineering. The EMG signal is the electrical manifestation of the neuromuscular activation associated with the contracting muscles. The signal represents the current generated by the ionic flow across the membrane of the muscle fibers which propagates through the intervening tissues to reach the detection surface of the electrode located in the environment. It is an exceedingly complicated signal which is affected by anatomical and physiological properties of muscles and the control scheme of the nervous system, as well as characteristics of the instrumentation used to detect and observe it. Most of the relationships between the EMG signal and the properties of contracting muscles that are currently in use have evolved serendipitously. The lack of proper description of the EMG signal is probably the greatest single factor that has hampered the development of electromyography in to a precise discipline. APPLICATIONS: To test the nerve and muscle activity To determine nerve conduction velocity to test nerve damage/compression To obtain firing characteristics of nerves. Analysis of motor unit action potentials To analyze the extent of nerve damage, muscular damage It is useful for gym trainees and sport persons to evaluate growth and development of specific muscles. It is useful for energy/fatigue analysis of industrial workers for time-motion-rest cycle evaluation for an efficient working environment. Usually passenger pilots are checked for their EMG levels before they take up a flight in order to ensure fatigue level of the pilot is at safe level. MUSCLES: About 40% of the human body is skeletal muscles and another 10% is smooth muscles of internal organs and cardiac muscles from the heart. Here we are interested in characterizing the function of skeletal muscles. The primary function of skeletal muscles is to generate force. Because of this, they are excitable. Thus skeletal muscles have 2 fundamental properties. They are excitable(able to respond to stimulus) and contractible(able to produce tension).A skeletal muscle consists of numerous fibers with diameters ranging from 10 to 80 Â µm. Each muscle fiber contains hundreds to thousands of myofibrils .Each myofibril has about 1500 myosin filaments and 3000 actins filaments lying side by side. Cell Potential: The nervous system is comprised of neuron cells. Neurons are the conducting elements of the nervous system and are responsible for transferring information across the body. Only these and muscle cells are able to generate potentials and therefore are called excitable cells. Neurons contain special ion channels that allow the cell to change its membrane potential in response to the stimuli the cell receives. Receiving Potential: All cells in the body have a cell membrane surrounding them. Across this membrane there is an electric charge referred to as the resting potential. This electric impulse is generated by differential ion permeability of the membrane. In the cells, potassium (k+) channels allow diffusion of k+ ions out of the cell while Sodium(Na+) ions diffuse in to the cell. This Na+-K+ pump, which requires ATP to operate, pumps two K+ ions in to the interior of the cell for every 3 Na+ ions pumped out. K+ and Na+ ions are continuously diffusing across the membrane from where they were just pumped, but at a slower rate. Since there are more K+ ions inside the cell than outside, a potential exists. Action Potential: Some cells, such as skin cells are not excitable. Other cells such as nerve and muscle cells are excitable. When a simulating electric field acts on an excitable cell, the Na+ permeability increases, Na+ enters the cell interior and the entering positive charge depolarizes(reduces to approximately zero),the transmembrane potential. Later the K+ permeability increases and K+ ions flow out to counter this effect. The Na+ gates close followed by the K+ gates. Finally, the resting potential is regenerated. The action potential lasts about 1ms in nerves and about 100 ms in cardiac muscle. It propagates in nerves at about 60 m/s and carries sensations from the periphery toward the brain via sensory nerves. Through motor nerves, the brain commands muscles to contract. We can calculate the action potential propagation velocity v=d/t where Figure shown here represents the role of voltage-gated ion channels in the action potential. The circled numbers on the action potential correspond to the 4 diagrams of voltage-gated sodium and potassium channels in a neurons plasma membrane. Motor Unit: The most fundamental unit of a muscle is called the Motor Unit. It consists of an alpha-motoneuron and all the muscle fibers that are enervated by the motoneurons branches. The electrical signal that emanates from the activation of muscle fibers of a motor unit that are in the detectable vicinity of an electrode is called MOTOR UNIT ACTION POTENTIAL (MUAP).This constitutes the fundamental unit of the EMG signal. A Schematic representation of the genesis of a MUAP is presented above. There are many factors that influence the shape of MUAP. Some of these are The relative geometrical relationship of the detection surface of the electrode and the muscle fiber of the motor unit in its vicinity. The relative position of the detection surfaces to the innervated zone, which is the region where the nerve branches contact the muscle fibers. The size of muscle fibers, because amplitude of individual action potential is proportional to the diameter of the fiber, and The number of muscle fibers of an individual motor unit in the detectable vicinity of the electrode. The last two factors have particular importance in clinical applications. Considerable work has been performed to identify morphological modifications in the MUAP shape resulting from modifications in the morphology of the muscle fibers or the motor unit such as regeneration of motoneurons. Although usage of MUAP shape analysis is common practice among neurologists, interpretation of the result is not always straight forward and relies heavily on the experience and disposition of the observer. To sustain muscle contraction, the motor unit must be activated repeatedly. The resulting sequence of MUAPs is called Motor Unit Action Potential Train(MUAPT).So, EMG signal can be synthesized by linearly summing the MUAPTs as they exist when they are detected by the electrode where mathematically generated MUAPTs are added to yield the signal at the bottom. MUSCLE CONTRACTION: As an action potential travels along a motor nerve to muscle fibers, it initiates an action potential along the muscle fiber membrane, which depolarizes the muscle fiber membrane and travels with in the muscle fiber. The Subsequent electro-chemical reaction with in the muscle fiber then initiates attractive forces between the actin and myosin filaments and causes them to slide together. This mechanism produces muscle contraction. Tension is developed in the muscle as it contracts. There are 3 types of contraction Isometric Concentric Eccentric Isometric or Static Contraction means a muscle contracts without change in its length. Concentric Contraction occurs when a load is less than the isometric force produced by the muscle and the load shortens the muscle. Eccentric Contraction occurs when the load is greater than the isometric force and elongates the contracting muscle.

Time Travel Essay -- essays research papers fc

Time travel is feat thought by most to be impossible. After all time travel is what many science fiction movies are made of. Let us not forget such movies as â€Å"Back to the Future† or â€Å"The Time Machine.† Yet unlike those movies time travel is not necessarily fiction. â€Å"We are in our own time machines, our hearts are pumping blood, we're breathing, we are existing through time (at least until our own personal time machines seriously malfunction).† (Need help citing this!) Still surrounding this topic is a series of theories, and surrounding these series is a number of flaws. Theories and flaws that need to be explained to fully understand the idea of time travel. First things first we must state the basics.   Ã‚  Ã‚  Ã‚  Ã‚  To begin with throw away whatever you thought you ever knew about time travel. There is no such thing as working time machines, you can’t go back in time by falling into a black hole, and sitting in a tub of water is not going to change you molecular structure and send it back in time by having you float through a wormhole. Time travel is achieved through speed; theoretically you must reach close to light speeds to go forward in time and faster than light speed to go back in time, according to Einstein’s theory of relativity mind you. Einstein’s theory of relativity is the basis of all time travel theories (Davies 1), â€Å"The essence of his prediction is that time is not absolute and universal but depends on the observer’s state of motion.† (Davies ...

History of Parental Involvement in Education Essay examples -- Parent

History of Parent Involvement Prior to the 1850’s, before public education existed, parents and families were responsible for the education of their children. During the late 1800’s and early 1900’s education in schools became wide spread. As public education grew and teachers became professionals many began to believe that professionals alone should be responsible for educating children (Stein and Thorkildsen). As years went by, families showed some concern about this new view on who should be in charge of their children’s education. Parents began to show their concern for this division in education in the 1987 when the National Congress of Mothers, the foundation for the Parent Teacher Association, was formed (Stein and Thorkildsen). Since 1987 many more steps have been taken in an effort to evaluate the importance of parent involvement in education and to encourage parents to be involved in their child’s schooling. Family Structure Parent involvement in a child’s schooling has proven to be beneficial to the child regardless of the situation. The amount of the effectiveness of the parent involvement is directly related to the structure of the family that the child comes from. A National Household Education Survey (NHES) from 1996 shows that children from dual parent homes are more inclined to excel academically and become involved in extracurricular activities. More so, they are not as likely to repeat a grade or be given a suspension, especially if their fathers show interest and become involved (Nord). In 38.5 percent of dual parent households parents actively help their child with homework three or more times a week (National Center for Education Statistics). In today’s ever changing society dual parent ho... ... EBSCO Database. Retrieved March 8, 2002 from Eric Database. U.S. Department of Education. (1991). Other middle grade resources, Parent involvement at the middle school level. National Committee for Citizens in Education. Retrieved February 18, 2002 from the World Wide Web: www.middleweb.com/ParntInvl.html This is a well designed web site that provides resources for parents and teachers of middle school aged children. Articles, news stories, diaries, chats, newsletters, and hot links are available on this web site. Wherry, J. (2002). Selected parent involvement research. The Parent Institute. Retrieved April 11, 2002 from the world wide web : http://www.par-inst.com/edresources/research/research.shtml This bit of selected research comes from the parent institute web site. The information provided on this page is supported by numerous references.

Lord of the flies writing assignment

They were reported issuing a month ago on Tuesday July 21st, after a plane supposedly â€Å"dropped† them off at a Remote Island. No one hasn't really heard of them since, but Police from all over Canada, the United States, Mexico, and the UK has been looking for these boys. Officials say that some sailors have found them on an island, which was smoking. Around 2-3 boys have been reported dead; the names have not been released as yet. â€Å"We found shelter, and got some food† 8 year old Sam, a younger boy rescued from the island. â€Å"Some of the boys were rude to other boys but they solved some of their problems† 8 ear old Eric said.Now the big question is what happened on the island? â€Å"On that island, have been some really traumatizing events. Some have lost their lives on that island, but most survived. There have been some really awful conflicts but thankfully reality saved us. † 12 year old Ralph said. ‘We were civilized at one point in ti me but we got out of hand, but I'm glad that's all over and that we can move on in our lives. † 12 year old Jack told us. All the boys are safe home now and officers are going back to the island to investigate and find the lost boys.