The Neurobiology of Memory and Aging Essay -- Science Scientific Essay

The Neurobiology of Memory and Aging "I lost my keys again," my mother exclaimed at dinner a few nights ago, "I really am getting old." This use of old age as a justification for memory deficits is extremely common. Many people relate old age with loss of memory and other neurobiological functions. Why is it that aging seems to go hand in hand with losing and forgetting things? Is there a neurobiological explanation for this phenomenon? It is clear to neurobiologists that aging results in a decrease in brain size as well as a decrease in the efficiency of brain functions. It has been a widely held belief that aging causes neurons to die and for the overall number of neurons to decrease as one reaches old age. Studies conducted by Dr. David Merrill refute this idea, sighting a lack of neuronal loss in the entohinal cortex after running an MRI on a healthy subject. Instead, Merill indicates that loss of neurons may occur in degenerative disorders, such as Alzheimers, but not in healthy brains. However, it remains true that some aspects of cognition do decline as age increases, such as short term and long term memory. Since these effects are not caused by a decrease in the number of neurons present, there must be another neurobiological explanation. In order to understand memory loss it is necessary to understand how memory works in a normal brain without any cognitive deficits. Memory can be separated into three distinct parts: working memory, declarative memory, and procedural memory (1). Working memory is the most short term, and it involves repeating something that someone has just said in conversation or remembering something you had just seen briefly. This part of memory does not ever become fully sto... ...mplex.. http://psych.wisc.edu/postlab/Psych733/Nadel_Moscovitch.1997.pdf 4)Nadel and Moscovitch. "Memory Consolidation, Retrograde Amnesia and the Hippocampal Complex.. http://psych.wisc.edu/postlab/Psych733/Nadel_Moscovitch.1997.pdf 5) The Symptoms of Alzheimer's. . http://www.diseases-explained.com/Alzheimers/symptomsalzheime.html 6) Greenwood. . http://sln.fi.edu/brain/nutrition/carbohydrates/brainpower.html 7) Alzheimer's Secondary Victims. . http://sites.unc.edu/error.html 8)Alipoprotein E. . http://home.mira.net/~dhs/apoe.html 9) Determining the Cause of Memory Loss in the Elderly . http://www.postgradmed.com/issues/1999/10_15_99/welsh.htm 10)Stress tied to Memory Loss . http://www.academicpress.com/inscight/04221998/grapha.htm 11)University of Kuopio, Series Reports, Department of Neurology . http://www.uku.fi/neuro/39abs.htm The Neurobiology of Memory and Aging Essay -- Science Scientific Essay The Neurobiology of Memory and Aging "I lost my keys again," my mother exclaimed at dinner a few nights ago, "I really am getting old." This use of old age as a justification for memory deficits is extremely common. Many people relate old age with loss of memory and other neurobiological functions. Why is it that aging seems to go hand in hand with losing and forgetting things? Is there a neurobiological explanation for this phenomenon? It is clear to neurobiologists that aging results in a decrease in brain size as well as a decrease in the efficiency of brain functions. It has been a widely held belief that aging causes neurons to die and for the overall number of neurons to decrease as one reaches old age. Studies conducted by Dr. David Merrill refute this idea, sighting a lack of neuronal loss in the entohinal cortex after running an MRI on a healthy subject. Instead, Merill indicates that loss of neurons may occur in degenerative disorders, such as Alzheimers, but not in healthy brains. However, it remains true that some aspects of cognition do decline as age increases, such as short term and long term memory. Since these effects are not caused by a decrease in the number of neurons present, there must be another neurobiological explanation. In order to understand memory loss it is necessary to understand how memory works in a normal brain without any cognitive deficits. Memory can be separated into three distinct parts: working memory, declarative memory, and procedural memory (1). Working memory is the most short term, and it involves repeating something that someone has just said in conversation or remembering something you had just seen briefly. This part of memory does not ever become fully sto... ...mplex.. http://psych.wisc.edu/postlab/Psych733/Nadel_Moscovitch.1997.pdf 4)Nadel and Moscovitch. "Memory Consolidation, Retrograde Amnesia and the Hippocampal Complex.. http://psych.wisc.edu/postlab/Psych733/Nadel_Moscovitch.1997.pdf 5) The Symptoms of Alzheimer's. . http://www.diseases-explained.com/Alzheimers/symptomsalzheime.html 6) Greenwood. . http://sln.fi.edu/brain/nutrition/carbohydrates/brainpower.html 7) Alzheimer's Secondary Victims. . http://sites.unc.edu/error.html 8)Alipoprotein E. . http://home.mira.net/~dhs/apoe.html 9) Determining the Cause of Memory Loss in the Elderly . http://www.postgradmed.com/issues/1999/10_15_99/welsh.htm 10)Stress tied to Memory Loss . http://www.academicpress.com/inscight/04221998/grapha.htm 11)University of Kuopio, Series Reports, Department of Neurology . http://www.uku.fi/neuro/39abs.htm

Rh Bill & Malthusian Theory Essay

In 2011, we have now seven billion people living in this planet. Unfortunately, Earth’s estimated carrying capacity is only about eleven to twelve billion people. With such a big problem we are facing today, it is important to analyze and examine what the scholars of the past have to say of our increasing population. One of the famous population theorists of that time is Thomas Malthus. In 1798, Malthus proposes his own theory about population. According to him, human populations grow exponentially while food production grows at an arithmetic rate. Thus, if the increase in our population is not controlled properly, then the number of the people would increase faster than the food supply. He stated that if this growth rate is allowed to continue, it would lead to a food shortage. To solve this problem, he proposed three solutions. The first one is positive check. This method increases death rates due to wars, famines, disease, and natural disasters. Preventive or negative check is the other one. It lowers the birth rate which is accomplished through abortion, birth control, and celibacy. The last one is moral restraint which is refraining from marriage until the time when a person is capable of supporting a family. This two hundred-year-old theory is now happening these days. It predicted the problems of food shortage that the world is experiencing today because of the uncontrolled increase in population. Still, I cannot fully agree with Malthus because there are things that he forgot to take into consideration when he formulated this theory. One is the ability of man to increase the food production as stated by Marx. He failed to recognize man’s ability to use science and technology to solve these population problems like the possible developments in agricultural technology which can increases the supply of food. Maybe during that time, science is making a slow progress that he assume we cannot remedy these problems. Another one is the use of birth control as a way of reducing population. He believed that having only few kids is the only way to stop or control the increasing growth rate. Moreover, he confused the desire for sexual relationships with the desire to have children. He didn’t realize that a person can still engage in a sexual relationship and still don’t have a child with the help of contraceptives. Although Malthus’ theory has some loopholes, the essentials of the theory have not yet been demolished. There are some assumptions that turned out to be true. RH bill The reproductive health bill which is now a law is the most controversial bill in the Philippines for decades which date back to 1967. The bill is composed of topics which deal with issues about family planning, maternal and child health, and reproductive and sexual conditions. Its main objective is to lift the reproductive standards of Filipinos by promoting respect for life, informed choice, birth spacing and responsible parenthood which is accordance with the human rights standards. It also guarantees access to medically-safe, legal and quality reproductive health care services and relevant information. Although it has promising merits, I do not support the bill because of some of its faulty assumptions. One is the assumption that overpopulation is the cause of poverty. In truth, there is really no relationship between overpopulation and poverty but RH bill still insists that it is the cause of the worsening poverty in our country. It is true that it is one of the factors but it is never the root cause of poverty. What is the primary cause of poverty are the corruption and the bad governance of the administration. In fact, we are one of the most corrupt countries in Southeast Asia. Another assumption is that Philippines is overpopulated. In reality, there is no overpopulation in our country. It is true that our cities are densely populated but in some parts of our country, there are small numbers of people and some are still uninhabited. One more problem in the bill is the belief that contraceptives will prevent abortion and sexually transmitted diseases. We should not entrust our safety to the use of these contraceptives in the prevention of STDs because according to some studies, there is no proof that condoms, for example, is effective in preventing STDs. In the case of abortions, it did not really lessen the incidents. According to a study in Spain, a 10-year period of an increasing use of contraceptive devises had been paralleled by a significantly increasing number of abortions. Though it is already a law, I hope that it can still be corrected so that it can truly uplift the standards of living of the Filipino people and be the solution to lessen the country’s underemployment and booming population.

How to Convert Celsius and Fahrenheit

Most countries around the world measure their weather and temperatures using the relatively simple Celsius scale. But the United States is one of the five remaining countries that use the Fahrenheit scale, so its important for Americans to know how to convert one to the other, especially when traveling or doing scientific research.   Celsius Fahrenheit Conversion Formulas To convert a temperature from Celsius to Fahrenheit, you will take the temperature in Celsius and multiply it by 1.8, then add 32 degrees. So if your Celsius temperature is 50 degrees, the corresponding Fahrenheit temperature is 122 degrees: (50 degrees Celsius x 1.8) 32 122 degrees Fahrenheit If you need to convert a temperature in Fahrenheit, simply reverse the process: subtract 32, then divide by 1.8. So 122 degrees Fahrenheit is still 50 degrees Celsius: (122 degrees Fahrenheit - 32)  Ãƒ · 1.8 50 degrees Celsius Its Not Just About Conversions While its useful to know how to convert Celsius to Fahrenheit and vice versa, its also important to understand the differences between the two scales. First, its important to clarify the difference between Celsius and centigrade, since theyre not quite the same thing.   A third international unit of temperature measurement, Kelvin, is widely used in scientific applications. But for everyday and household temperatures (and your local meteorologists weather report), youre most likely to use Fahrenheit in the U.S. and Celsius most other places around the world.   Difference Between Celsius and Centigrade Some people use the terms Celsius and centigrade interchangeably, but its not completely accurate to do so.  The Celsius scale is a type of centigrade scale, meaning its endpoints are separated by 100 degrees. The word is derived from the Latin words centum, which means hundred, and gradus, which means scales or steps. Put simply, Celsius is the proper name of a centigrade scale of temperature. As devised by Swedish astronomy professor Anders Celsius, this particular  centigrade scale had  100  degrees occurring at the freezing point of water and 0 degrees as waters boiling point. This was reversed after his death by fellow Swede and botanist Carlous Linneaus to be more easily understood. The centigrade scale Celsius created was renamed for him after it was redefined to be more precise  by the General Conference of Weights and Measures in the 1950s.   There is one point on both scales where Fahrenheit and Celsius temperatures match, which is minus 40 degrees Celsius and minus 40 degrees Fahrenheit.   Invention of the Fahrenheit Temperature Scale The first mercury thermometer was invented by German scientist Daniel Fahrenheit in 1714. His scale divides the freezing and boiling points of water into 180 degrees, with 32 degrees as waters freezing point, and 212 as its boiling point. On Fahrenheits scale, 0 degrees was determined as the temperature of a brine solution. He based the scale on the average temperature of the human body, which he originally calculated at 100 degrees (its since been adjusted to 98.6 degrees). Fahrenheit was the standard unit of measure in most countries until the 1960s and 1970s when it was replaced with the Celsius scale in a widespread conversion to the more useful metric system. But in addition to the U.S. and its territories,  Fahrenheit is still used in  the Bahamas, Belize, and the Cayman Islands for most temperature measurements.