MILESTONES IN THE GENETIC REVOLUTION
Charles Darwin & Alfred Russel Wallace
The theory of evolution 1858
Gregor Mendel
The laws of the genetic inheritance
1865
Friedrich Miescher
The discovery of the presence of DNA in the nucleus
1869
Beadle & Tatum The law “one gen one enzyme” 1941
Oswald Avery, Colin McLeod & Maclyn McCarty
Demonstration that the genetic information resides in the molecule of DNA 1944
Erwin Chargaff The discovery of the link between Adenine and Timine, and between Citosine and Guanine
1950
Rosalind franklin
Images of christalyzed DNA Through X rays 1952
James Watson & Francis Crick
Discovery of the structure of the DNA molecule 1953
Francois Jacob & Jacques Monod
The theory of the “operon” (regulation of the genic expression)
1961
Niremberg & Matthei
The first elucidation of a codon (the first step in the discovery of the genetic code) 1961
Severo Ochoa Discovery of the genetic code 1962
An international team
Finishes the project “Human Genome” 2001
martes, 10 de noviembre de 2009
martes, 20 de octubre de 2009
Proposed questions for a written proof
SCIENCE IN SOCIETY
QUESTIONS FOR THE FIRST UNIT
1. Can you explain what a pendulum is? What is the period of a pendulum?
2. Explain every step of the scentific method applied to the period of a pendulum (if you don´t remember the figures in the experiment you can invent them).
3. You have a goldfish bowl at home, but your goldfishes dye after some days. It has happened every time you have tried to breed goldfishes. You suspect that the problem could be an excesive amount of food. Apply the scientific method to this problem (you can invent the results of the experiments).
4. The scientist of the XVIIth century Jean Baptiste Von Helmont famous for his investigations on plants fisiology, published this recippe to create mice: “leave some some wheat beans anda ditrty shirt in a timber box for some days and out of the interaction between them some mice would appear”.
Criticice this experiment using the scientific method and give an alternative explanation to the results of this experiment.
5. Do you think that a contrasted and prestigious theory can be considered the “truth”? Explain why
6. Do you think that the explanation of the origin of the Universe in the Bible could be considered the “truth” by a christian? In what sense?
7. Can you summarise briefly the core of the discussion between Robert Penrose and Stephen Hawkings about the meaning of their investigations about Black Holes?
8. Whose opinion do you like more, Penrose´s or Hawkings´?
9. Write down in words this expresion “10-31”
10. Apply the principle of ockham’s razor to this problem:
“some people suspect that crop circles are due in some way to extraterrestrial influence, whether directly or otherwise. Others suggest that the patterns are the work of dedicated artists or hoaxers and very much an earthly occurrence.”
11. Arno Penzias and Robert Wilson were two of the technicians that were making proofs for the firsts intercontinental TV transmisions, and while doing this they came across the cosmic microwave background radiation and received the Nobel award after this discovery.
What name receives in science this kind of discovery?
12.
QUESTIONS FOR THE FIRST UNIT
1. Can you explain what a pendulum is? What is the period of a pendulum?
2. Explain every step of the scentific method applied to the period of a pendulum (if you don´t remember the figures in the experiment you can invent them).
3. You have a goldfish bowl at home, but your goldfishes dye after some days. It has happened every time you have tried to breed goldfishes. You suspect that the problem could be an excesive amount of food. Apply the scientific method to this problem (you can invent the results of the experiments).
4. The scientist of the XVIIth century Jean Baptiste Von Helmont famous for his investigations on plants fisiology, published this recippe to create mice: “leave some some wheat beans anda ditrty shirt in a timber box for some days and out of the interaction between them some mice would appear”.
Criticice this experiment using the scientific method and give an alternative explanation to the results of this experiment.
5. Do you think that a contrasted and prestigious theory can be considered the “truth”? Explain why
6. Do you think that the explanation of the origin of the Universe in the Bible could be considered the “truth” by a christian? In what sense?
7. Can you summarise briefly the core of the discussion between Robert Penrose and Stephen Hawkings about the meaning of their investigations about Black Holes?
8. Whose opinion do you like more, Penrose´s or Hawkings´?
9. Write down in words this expresion “10-31”
10. Apply the principle of ockham’s razor to this problem:
“some people suspect that crop circles are due in some way to extraterrestrial influence, whether directly or otherwise. Others suggest that the patterns are the work of dedicated artists or hoaxers and very much an earthly occurrence.”
11. Arno Penzias and Robert Wilson were two of the technicians that were making proofs for the firsts intercontinental TV transmisions, and while doing this they came across the cosmic microwave background radiation and received the Nobel award after this discovery.
What name receives in science this kind of discovery?
12.
lunes, 19 de octubre de 2009
A flu: questions and information
When you read or listen to news about the bird flu, you might hear about the spread of H5N1, the mad dash to buy Tamiflu, or the warnings of a pandemic. However, one thing that is overlooked often is the virus's mechanics. In other words, how does it work?
Anatomy of a virus
Diagram of an influenza virus (Paul Digard)
If you were to look at an influenza virus through a microscope, it would look like a sphere with many spikes and mushroom shaped objects on its surface. The exterior of the virus is composed of a lipid (fat) envelope covered with two types of protein molecules called surface antigens. The spikes are known as hemagglutinin (HA) and the mushrooms are known as neuraminidase (NA). Each hemagglutinin spike is made up of three entwined molecules while each neuraminidase mushroom is comprised of four entwined molecules. Also on the surface of the virus are M2 proteins, which allow the virus to adjust its interior acidity. Inside the lipid envelope, there are eight RNA gene segments called RNPs (RNA molecule+ Nucleoprotein+ Polymerases). Finally, there are the ball shaped M1 proteins, which act as cushions for the RNPs inside.
Skip this Section
A CLOSER LOOK: What's in a name?
H5N1, H1N1, H3N2... the flu virus designations are interesting and puzzling. But how do scientists come up with these strange names. According to experts, there are 15 different types of hemagglutinin molecules and 9 different types of neuraminidase molecules. Virologists identify Influenza A viruses by their specific hemagglutinin and neuraminidase molecules. In 1980, scientists adopted a general formula for naming Influenza A viruses, HxNy (x represents the type of hemagglutinin molecule and y represents the type of neuraminidase molecule.)
For example, an avian flu virus with hemagglutinin molecule 3 and neuraminidase molecule 2, its name would be H3N2.
How influenza replicates
The process of cell replication can be explained in three phases: initiation, replication, and release.
Initiation
During initiation, the hemagglutinin (HA) spikes bind to the surface of a cell. After binding, the virus is enveloped by a capsule made from the cell's membrane, which then breaks off from the surface and goes into the cell. This process is known as endocytosis. After entering the cell, the virus's M2 protein pumps ions into the capsule, to make it more acidic. When the capsule becomes acidic enough, the virus will merge with the capsule. Eventually, a hole is formed and the RNPs leave the capsule, heading straight for the cell's nucleus, where replication begins.
Diagram of influenza replication (Microbiology @ Leicaster)
Replication
The RNPs enter the nucleus, where new viral RNA and proteins will be produced. Inside the nucleus, the virus's genetic blueprint (known as vRNA) produces messenger RNA (mRNA) and direct copies of its genetic material (cRNA). The mRNA 'oversees' the making of various proteins, while the cRNA is used to make additional copies of the virus's genetic material. Hemagglutinin, neuraminidase, and M1 proteins form on the outside of the cell membrane, while newly made nucleoproteins combine with vRNA to form nucleocapsids, another name for the RNPs. With everything in place, the release phase begins.
Release
During the final phase, the nucleocapsids are assembled and the new virus particles begin to take shape. After assembly, the viruses are released from the cell, in a process known as budding. New virus particles are gradually released from the cell for several hours until the cell eventually dies off. The new viruses then attach themselves to new cells, starting the process of replication again.
Three essential facts
1. RNA is extremely error prone: on average, each new virus differs from its parent by at least one nucleotide.
2. Influenza is the only virus that undergoes true antigenic drift (genetic changes in the virus that occur because of errors in replication.)
3. Two different viruses can infect a cell at the same time. For instance, if human and an avian flu virus infect a pig cell, they can swap genes. This swap results in a new flu subtype that has both avian and human flu characteristics. This 'reassortment' is known as antigenic shift.
WHAT DO YOU KNOW ABOUT “A” FLU (SWINE FLU)
1. You would have heard that swine flu is a pandemic, but what does this word mean?
2. Is it the same disease as the normal (seasonal flu)?
3. Has it got any relationship with avian flu (bird flu)?
4. Tell wether these sentences are true or false
a. We’ve got a vaccine for “A” flu but it is not very effective.
b. “A” flu is more dangerous than seasonal flu because it’s mortality rate is bigger.
c. A mask for your mouth and nose is a good means not to catch flu.
d. The best means to prevent catching “A” flu is to clean frequently your hands.
e. Young people catch “A” flu more easily than seasonal flu.
f. Symptoms of “A” flu are more serious than those of the seasonal flu.
g. The use of antibiotics is very effective for treating the flu.
h. We have not at present any good treatment for “A” flu.
i. Normal vaccine for seasonal flu is also useful for “A” flu.
j. The flu is caused by a Virus.
k. But “A” flu is caused by a bacteria.
l. Normal antivirals are not effective against “A” flu
m. Risk goups are the same as with seasonal flu.
5. What`s “Tamiflu”?
6. Describe very shortly what a virus is. If possible draw a picture.
7. Have you ever heard about the “Spanish flu”?. If not look for information.
8. The “World Health Organisation” (WHO) don´t consider any more the term “swine flu”as correct, instead they propose the term “H1N1 flu”. Could you give a reason for that?
Pandemic (H1N1) 2009 - update 67
Weekly update
As of 20 September 2009, there have been more than 300,000 laboratory confirmed cases of pandemic influenza H1N1, 3917 deaths, in 191 countries and territories reported to WHO.
As more and more countries have stopped counting individual cases, particularly of milder illness, the case count is significantly lower than the actually number of cases that have occurred. While the case counts no longer reflect actual disease activity, WHO is actively monitoring the progress of the pandemic through frequent consultations with the WHO Regional Offices and member states and through monitoring of multiple sources of data.
In the temperate regions of the northern hemisphere, influenza-like-illness (ILI) activity continues to increase in many areas. In North America, the United States has reported continued increases in activity above the seasonal baseline for the last 2 to 3 weeks, primarily in the southeast but now also appearing in the upper midwest and the northeast. In Europe and Central and Western Asia, the United Kingdom is reporting regional increases in ILI activity in Northern Ireland and Scotland and the Netherlands, France, Ireland, and Israel are reporting rates above the seasonal baseline. In In Japan, influenza activity continues to be slightly above the seasonal epidemic threshold. The increases in ILI activity have been accompanied by increases in laboratory isolations of pandemic influenza H1N1 2009 in most of these areas.
In the tropical regions of the Americas and Asia, influenza activity remains variable. In parts of India, Bangladesh and Cambodia, influenza transmission continues to be active, while other countries in the Southeast Asia have been recently reporting declining transmission (Indonesia, Singapore and Thailand). Although most countries in the tropical regions of the Americas are still reporting regional to widespread geographic spread of influenza activity, there is no consistent pattern in the trend of respiratory diseases. Peru and Mexico have reported an increasing trend in some areas, while most others are reporting an unchanged or decreasing trend (most notably Bolivia, Venezuela and Brazil).
In the temperate regions of the southern hemisphere, influenza transmission has largely returned to baseline (Chile, Argentina, and New Zealand) or is continuing to decline (Australia and South Africa).
All pandemic H1N1 2009 influenza viruses analyzed to date have been antigenically and genetically similar to A/California/7/2009-like pandemic H1N1 2009 virus. See below for a detailed laboratory surveillance update.
About pandemic flu
• Last modified date:
1 May 2009
A pandemic is a global disease outbreak. Pandemic flu occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily from person to person, causes serious illness and can sweep across the country in which it originates and around the world in a very short time.
In contrast to the ‘ordinary’ or ‘seasonal’, flu outbreaks which we see every winter in the UK, flu pandemics occur infrequently - usually every few decades. There were three last century. The most serious was in 1918, killing millions of people worldwide and smaller pandemics happened in 1957 and 1968.
Are we at risk now?
A pandemic can only start when three conditions have been met:
• a new influenza virus subtype emerges
• it infects humans, causing serious illness
• it spreads easily and sustainably among humans.
When will a pandemic arrive in UK?
We do not know – it can’t be predicted. The gaps between previous pandemics have varied widely. Intervals between previous pandemics have varied from 11 to 42 years with no recognisable pattern. Three influenza pandemics occurred in the last century – 1918/19 (Spanish flu), 1957/58 (Asian flu) and 1968/69 (Hong Kong flu). All affected large numbers of the population, causing many deaths and huge economic and social disruption.
How long will it take to arrive in the UK?
Probably less than six months and possibly just a few weeks or less, but this will depend upon where the pandemic emerges. Of course, it is important to remember that the pandemic could emerge in the UK. The increasing speed and volume of modern travel means infectious diseases can travel very rapidly around the globe.
Can it be prevented at any stage?
International effort will be made in trying to control a pandemic when it emerges. However, influenza is highly infectious and because whole populations will be susceptible to the new virus, despite people’s best efforts, it is likely to continue to spread.
The World Health Organisation (WHO) has purchased a stockpile of antivirals which can be transported to the source of the outbreak. It is hoped that these antivirals may help to contain the emerging virus.
Who is at risk?
We cannot know which groups will be affected by pandemic flu until the virus emerges. However, we know from previous pandemics that a future one is likely to have a major impact worldwide and from experience of previous pandemics we know that it is not necessarily the young and the elderly that will be affected.
How is the virus spread?
The virus is easily passed from person to person by breathing in air containing the virus produced when an infected person talks, coughs or sneezes. It can also spread through hand/ face contact after touching a person or surface contaminated with the virus.
Symptoms
Pandemic flu is likely to cause the same symptoms as ordinary flu but the symptoms may be more severe because nobody will have any immunity or protection against that particular virus. People infected with the current strand of the avian virus (H5N1) have shown everything from typical human influenza-like symptoms (fever, cough, sore throat, and muscle aches) to pneumonia, severe respiratory diseases, and other life-threatening complications.
Influenza
Influenza, or 'flu', is a highly contagious acute viral infection that affects people of all ages. It typically starts suddenly with fever, chills, headache, aching muscles, general prostration and a cough or other respiratory symptoms.
While most people recover without complications in 1-2 weeks, flu can cause serious illness and death, especially in the very young and the elderly.
Flu epidemics occur mainly in the winter months and can result in widespread disruption to healthcare and other services. A vaccine is produced every year based on the strains of virus expected to be circulating.
Swine flu
This section contains information related to the recent swine flu outbreak.
Pandemic flu
A pandemic occurs when a new influenza virus, which people have no immunity to, emerges and starts spreading as easily as normal influenza. The Department of Health is working to support NHS preparedness and to reduce the impact of pandemic flu on the UK population.
This is generic guidance intended to assist in preparing for a pandemic whose nature and severity is unknown. Although much of the content remains relevant in the current swine flu pandemic, some aspects, particularly those relating to at risk groups and those intended to respond to higher levels of sickness and mortality may not be applicable to the current swine flu situation. Therefore, the guidance should be read in conjunction with the latest swine flu UK planning assumptions and other specific swine flu guidance
Pandemic (H1N1) 2009 Influenza: Information for health professionals
Slowing the spread in the early stages of the current H1N1 influenza pandemic has given the HPA and the health service time to learn more about the new virus, build up antiviral and antibiotic stockpiles, and start to develop a pandemic specific vaccine.
This section contains advice and information for healthcare professionals.
Clinical diagnostic criteria
Clinicians are now encouraged to diagnose pandemic (H1N1) 2009 influenza cases on the basis of symptoms.
The clinical diagnostic criteria are:
• Fever [pyrexia ≥38°C] or a history of fever,
AND
• influenza-like illness (TWO OR MORE of the following symptoms: cough; sore throat; rhinorrhoea; limb or joint pain; headache; vomiting or diarrhoea) OR
• severe and/or life-threatening illness suggestive of an infectious process
More information can be found in the Department of Health's swine flu clinical package.
Testing
There is no need to test patients in primary care or emergency departments where admission is not required.
Testing should only be considered if patients are hospitalised, for the control of infection in hospitals, as part of 'spotter' surveillance schemes, or if there are unusual syndromes that are considered to have an infectious basis.
domingo, 18 de octubre de 2009
The most deadly four infectious diseases worldwide
Find out which are those infectious diseases and look for information on these aspects of them:
1.- Infectious agent
2.- Vector
3.- Symptoms
4.- Mortality rate
5.- Incicidence at present
6.- Prevalence at present (last year, month or week)
1.- Infectious agent
2.- Vector
3.- Symptoms
4.- Mortality rate
5.- Incicidence at present
6.- Prevalence at present (last year, month or week)
Inportant concepts in epidemiology
Define these terms of epidemiology: (don't forget mentioning your source)
1.- Infectious agent
2.- Vector
3.- Prevalence
4.- Incidence
5.- Mortality
6.- Morbidity
1.- Infectious agent
2.- Vector
3.- Prevalence
4.- Incidence
5.- Mortality
6.- Morbidity
martes, 29 de septiembre de 2009
Updates about "H1N1" pandemic
Pandemic (H1N1) 2009 - update 67
Weekly update
As of 20 September 2009, there have been more than 300,000 laboratory confirmed cases of pandemic influenza H1N1, 3917 deaths, in 191 countries and territories reported to WHO.
As more and more countries have stopped counting individual cases, particularly of milder illness, the case count is significantly lower than the actually number of cases that have occurred. While the case counts no longer reflect actual disease activity, WHO is actively monitoring the progress of the pandemic through frequent consultations with the WHO Regional Offices and member states and through monitoring of multiple sources of data.
In the temperate regions of the northern hemisphere, influenza-like-illness (ILI) activity continues to increase in many areas. In North America, the United States has reported continued increases in activity above the seasonal baseline for the last 2 to 3 weeks, primarily in the southeast but now also appearing in the upper midwest and the northeast. In Europe and Central and Western Asia, the United Kingdom is reporting regional increases in ILI activity in Northern Ireland and Scotland and the Netherlands, France, Ireland, and Israel are reporting rates above the seasonal baseline. In In Japan, influenza activity continues to be slightly above the seasonal epidemic threshold. The increases in ILI activity have been accompanied by increases in laboratory isolations of pandemic influenza H1N1 2009 in most of these areas.
In the tropical regions of the Americas and Asia, influenza activity remains variable. In parts of India, Bangladesh and Cambodia, influenza transmission continues to be active, while other countries in the Southeast Asia have been recently reporting declining transmission (Indonesia, Singapore and Thailand). Although most countries in the tropical regions of the Americas are still reporting regional to widespread geographic spread of influenza activity, there is no consistent pattern in the trend of respiratory diseases. Peru and Mexico have reported an increasing trend in some areas, while most others are reporting an unchanged or decreasing trend (most notably Bolivia, Venezuela and Brazil).
In the temperate regions of the southern hemisphere, influenza transmission has largely returned to baseline (Chile, Argentina, and New Zealand) or is continuing to decline (Australia and South Africa).
All pandemic H1N1 2009 influenza viruses analyzed to date have been antigenically and genetically similar to A/California/7/2009-like pandemic H1N1 2009 virus. See below for a detailed laboratory surveillance update.
About pandemic flu
· Last modified date:
1 May 2009
A pandemic is a global disease outbreak. Pandemic flu occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily from person to person, causes serious illness and can sweep across the country in which it originates and around the world in a very short time.
In contrast to the ‘ordinary’ or ‘seasonal’, flu outbreaks which we see every winter in the UK, flu pandemics occur infrequently - usually every few decades. There were three last century. The most serious was in 1918, killing millions of people worldwide and smaller pandemics happened in 1957 and 1968.
Are we at risk now?
A pandemic can only start when three conditions have been met:
· a new influenza virus subtype emerges
· it infects humans, causing serious illness
· it spreads easily and sustainably among humans.
When will a pandemic arrive in UK?
We do not know – it can’t be predicted. The gaps between previous pandemics have varied widely. Intervals between previous pandemics have varied from 11 to 42 years with no recognisable pattern. Three influenza pandemics occurred in the last century – 1918/19 (Spanish flu), 1957/58 (Asian flu) and 1968/69 (Hong Kong flu). All affected large numbers of the population, causing many deaths and huge economic and social disruption.
How long will it take to arrive in the UK?
Probably less than six months and possibly just a few weeks or less, but this will depend upon where the pandemic emerges. Of course, it is important to remember that the pandemic could emerge in the UK. The increasing speed and volume of modern travel means infectious diseases can travel very rapidly around the globe.
Can it be prevented at any stage?
International effort will be made in trying to control a pandemic when it emerges. However, influenza is highly infectious and because whole populations will be susceptible to the new virus, despite people’s best efforts, it is likely to continue to spread.
The World Health Organisation (WHO) has purchased a stockpile of antivirals which can be transported to the source of the outbreak. It is hoped that these antivirals may help to contain the emerging virus.
Who is at risk?
We cannot know which groups will be affected by pandemic flu until the virus emerges. However, we know from previous pandemics that a future one is likely to have a major impact worldwide and from experience of previous pandemics we know that it is not necessarily the young and the elderly that will be affected.
How is the virus spread?
The virus is easily passed from person to person by breathing in air containing the virus produced when an infected person talks, coughs or sneezes. It can also spread through hand/ face contact after touching a person or surface contaminated with the virus.
Symptoms
Pandemic flu is likely to cause the same symptoms as ordinary flu but the symptoms may be more severe because nobody will have any immunity or protection against that particular virus. People infected with the current strand of the avian virus (H5N1) have shown everything from typical human influenza-like symptoms (fever, cough, sore throat, and muscle aches) to pneumonia, severe respiratory diseases, and other life-threatening complications.
Weekly update
As of 20 September 2009, there have been more than 300,000 laboratory confirmed cases of pandemic influenza H1N1, 3917 deaths, in 191 countries and territories reported to WHO.
As more and more countries have stopped counting individual cases, particularly of milder illness, the case count is significantly lower than the actually number of cases that have occurred. While the case counts no longer reflect actual disease activity, WHO is actively monitoring the progress of the pandemic through frequent consultations with the WHO Regional Offices and member states and through monitoring of multiple sources of data.
In the temperate regions of the northern hemisphere, influenza-like-illness (ILI) activity continues to increase in many areas. In North America, the United States has reported continued increases in activity above the seasonal baseline for the last 2 to 3 weeks, primarily in the southeast but now also appearing in the upper midwest and the northeast. In Europe and Central and Western Asia, the United Kingdom is reporting regional increases in ILI activity in Northern Ireland and Scotland and the Netherlands, France, Ireland, and Israel are reporting rates above the seasonal baseline. In In Japan, influenza activity continues to be slightly above the seasonal epidemic threshold. The increases in ILI activity have been accompanied by increases in laboratory isolations of pandemic influenza H1N1 2009 in most of these areas.
In the tropical regions of the Americas and Asia, influenza activity remains variable. In parts of India, Bangladesh and Cambodia, influenza transmission continues to be active, while other countries in the Southeast Asia have been recently reporting declining transmission (Indonesia, Singapore and Thailand). Although most countries in the tropical regions of the Americas are still reporting regional to widespread geographic spread of influenza activity, there is no consistent pattern in the trend of respiratory diseases. Peru and Mexico have reported an increasing trend in some areas, while most others are reporting an unchanged or decreasing trend (most notably Bolivia, Venezuela and Brazil).
In the temperate regions of the southern hemisphere, influenza transmission has largely returned to baseline (Chile, Argentina, and New Zealand) or is continuing to decline (Australia and South Africa).
All pandemic H1N1 2009 influenza viruses analyzed to date have been antigenically and genetically similar to A/California/7/2009-like pandemic H1N1 2009 virus. See below for a detailed laboratory surveillance update.
About pandemic flu
· Last modified date:
1 May 2009
A pandemic is a global disease outbreak. Pandemic flu occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily from person to person, causes serious illness and can sweep across the country in which it originates and around the world in a very short time.
In contrast to the ‘ordinary’ or ‘seasonal’, flu outbreaks which we see every winter in the UK, flu pandemics occur infrequently - usually every few decades. There were three last century. The most serious was in 1918, killing millions of people worldwide and smaller pandemics happened in 1957 and 1968.
Are we at risk now?
A pandemic can only start when three conditions have been met:
· a new influenza virus subtype emerges
· it infects humans, causing serious illness
· it spreads easily and sustainably among humans.
When will a pandemic arrive in UK?
We do not know – it can’t be predicted. The gaps between previous pandemics have varied widely. Intervals between previous pandemics have varied from 11 to 42 years with no recognisable pattern. Three influenza pandemics occurred in the last century – 1918/19 (Spanish flu), 1957/58 (Asian flu) and 1968/69 (Hong Kong flu). All affected large numbers of the population, causing many deaths and huge economic and social disruption.
How long will it take to arrive in the UK?
Probably less than six months and possibly just a few weeks or less, but this will depend upon where the pandemic emerges. Of course, it is important to remember that the pandemic could emerge in the UK. The increasing speed and volume of modern travel means infectious diseases can travel very rapidly around the globe.
Can it be prevented at any stage?
International effort will be made in trying to control a pandemic when it emerges. However, influenza is highly infectious and because whole populations will be susceptible to the new virus, despite people’s best efforts, it is likely to continue to spread.
The World Health Organisation (WHO) has purchased a stockpile of antivirals which can be transported to the source of the outbreak. It is hoped that these antivirals may help to contain the emerging virus.
Who is at risk?
We cannot know which groups will be affected by pandemic flu until the virus emerges. However, we know from previous pandemics that a future one is likely to have a major impact worldwide and from experience of previous pandemics we know that it is not necessarily the young and the elderly that will be affected.
How is the virus spread?
The virus is easily passed from person to person by breathing in air containing the virus produced when an infected person talks, coughs or sneezes. It can also spread through hand/ face contact after touching a person or surface contaminated with the virus.
Symptoms
Pandemic flu is likely to cause the same symptoms as ordinary flu but the symptoms may be more severe because nobody will have any immunity or protection against that particular virus. People infected with the current strand of the avian virus (H5N1) have shown everything from typical human influenza-like symptoms (fever, cough, sore throat, and muscle aches) to pneumonia, severe respiratory diseases, and other life-threatening complications.
What do you kow about "A" flu?
WHAT DO YOU KNOW ABOUT “A” FLU (SWINE FLU)
1. You would have heard that swine flu is a pandemic, but what does this word mean?
2. Is it the same disease as the normal (seasonal flu)?
3. Has it got any relationship with avian flu (bird flu)?
4. Tell wether these sentences are true or false
a. We’ve got a vaccine for “A” flu but it is not very effective.
b. “A” flu is more dangerous than seasonal flu because it’s mortality rate is bigger.
c. A mask for your mouth and nose is a good means not to catch flu.
d. The best means to prevent catching “A” flu is to clean frequently your hands.
e. Young people catch “A” flu more easily than seasonal flu.
f. Symptoms of “A” flu are more serious than those of the seasonal flu.
g. The use of antibiotics is very effective for treating the flu.
h. We have not at present any good treatment for “A” flu.
i. Normal vaccine for seasonal flu is also useful for “A” flu.
j. The flu is caused by a Virus.
k. But “A” flu is caused by a bacteria.
l. Normal antivirals are not effective against “A” flu
m. Risk goups are the same as with seasonal flu.
5. What`s “Tamiflu”?
6. Describe very shortly what a virus is. If possible draw a picture.
7. Have you ever heard about the “Spanish flu”?. If not look for information.
8. The “World Health Organisation” (WHO) don´t consider any more the term “swine flu”as correct, instead they propose the term “H1N1 flu”. Could you give a reason for that?
1. You would have heard that swine flu is a pandemic, but what does this word mean?
2. Is it the same disease as the normal (seasonal flu)?
3. Has it got any relationship with avian flu (bird flu)?
4. Tell wether these sentences are true or false
a. We’ve got a vaccine for “A” flu but it is not very effective.
b. “A” flu is more dangerous than seasonal flu because it’s mortality rate is bigger.
c. A mask for your mouth and nose is a good means not to catch flu.
d. The best means to prevent catching “A” flu is to clean frequently your hands.
e. Young people catch “A” flu more easily than seasonal flu.
f. Symptoms of “A” flu are more serious than those of the seasonal flu.
g. The use of antibiotics is very effective for treating the flu.
h. We have not at present any good treatment for “A” flu.
i. Normal vaccine for seasonal flu is also useful for “A” flu.
j. The flu is caused by a Virus.
k. But “A” flu is caused by a bacteria.
l. Normal antivirals are not effective against “A” flu
m. Risk goups are the same as with seasonal flu.
5. What`s “Tamiflu”?
6. Describe very shortly what a virus is. If possible draw a picture.
7. Have you ever heard about the “Spanish flu”?. If not look for information.
8. The “World Health Organisation” (WHO) don´t consider any more the term “swine flu”as correct, instead they propose the term “H1N1 flu”. Could you give a reason for that?
domingo, 27 de septiembre de 2009
ABOUT OCKHAM’S RAZOR
Consider these theories about the movement of planets, and select one of them by using the principle of Ockham’s razor. Justify your election
• The planets move around the sun in ellipses because there is a force between any of them and the sun which decreases as the square of the distance.
• The planets move around the sun in ellipses because there is a force between any of them and the sun which decreases as the square of the distance. This force is generated by the will of some powerful aliens.
Answer this question and send me the answer to my e-mail account
Consider these theories about the movement of planets, and select one of them by using the principle of Ockham’s razor. Justify your election
• The planets move around the sun in ellipses because there is a force between any of them and the sun which decreases as the square of the distance.
• The planets move around the sun in ellipses because there is a force between any of them and the sun which decreases as the square of the distance. This force is generated by the will of some powerful aliens.
Answer this question and send me the answer to my e-mail account
martes, 22 de septiembre de 2009
Find out information about these topics
1.- Ockham's razor
2.- Serendipity of science
3.- Fundamental science
4.- Karl Popper
The information must be:
* Short and made on your own ( no copies from the internet)
* Sources of information must be mentioned
2.- Serendipity of science
3.- Fundamental science
4.- Karl Popper
The information must be:
* Short and made on your own ( no copies from the internet)
* Sources of information must be mentioned
Heartbeat rate
THE SCIENTIFIC METHOD
INTRODUCTION
Science has been described as a way of knowing. It emerges from man's curiosity about ourselves and the world around us. Seeking to understand seems to be one of our basic drives. We ask questions that arise from our observations of natural things; and we seek discovery of answers. Striving to reveal the secrets of nature, scientists have devised a method of getting at the truth or solving problems. This is called the scientific method. Actually, there are many methods but they all bear common features or rules.
Is the scientific method something that only scientists can use? Certainly not; its usefulness extends to all of us, even in our daily lives. For example, I can use it to find why my car will not start. Or, I can find out what foods give me a stomachache.
Despite what the scientist wants to find out and the exact procedure used, certain features of the scientific method are common. Scientists make observations that lead them to ask questions. They make educated guesses about possible answers, then devise ways to test their guesses. In its classical form the scientific method involves the following steps:
1. Observation and Stating of a Problem - Scientific investigations usually begin with an observation that stimulates a desire to know or understand. The scientist then states the problem as clearly and concisely as possible.
2. Collection of Pertinent Information - An attempt should be made to assemble the pertinent facts concerning the problem. The scientist seeks to tap into as much available information about the problem as possible. This information may come from the library, the worldwide web, colleagues, or from other available sources.
3. Formulation of a Hypothesis - Based on information assembled in step two above, a tentative explanation or hypothesis is advanced. Some call this an educated guess. This is a trial idea, a possible solution to the problem. A key feature of the hypothesis is that it can be tested or validated.
4. Testing of the Hypothesis - In this step the scientist designs and executes an experiment to test the validity of the hypothesis. The exact design of this test can vary greatly and depends upon the nature of the study and the creativity of the investigator. The experiment must be carefully planned and conducted with great precision. Scientists strive to eliminate all human and instrumental bias. Accurate records as quantifiable data must be kept of every phase of the experiment. Results of the experiment are gathered and analyzed. Many experiments consist of a control group and an experimental group. The experimental group is identical to the control group in every respect except one, called the variable. The one substance, situation, etc. that is being tested is varied. All other factors are kept constant in both the experimental group and the control group. Therefore, the control serves as the basis or standard by which it is determined if the one variable is responsible for any differences in results. A key feature of the experiment is that it must be repeatable. That is, other researchers must be able to repeat the experiment under the same conditions and achieve the same results.
5. Conclusion - When the experiment is complete, the researcher must evaluate the results in an effort to reach a conclusion. The conclusion either supports or fails to support the original hypothesis. In either case, knowledge is gained and the researcher moves on.
6. Publication of Results - While your personal use of the scientific method does not involve this step, it is vital to the scientist. This requires publication, in appropriate scientific literature, of a detailed report of the problem, the hypothesis, all experimental methods and results, and the conclusions reached by the investigator. This allows other scientists to repeat the investigation if they choose, as a way of confirming the validity of the study.
LABORATORY EXERCISE PROCEDURE
Use the indicated steps of the scientific method with each of the following three (3) exercises. These exercises are designed to provide some experience using the scientific method as a way to acquire knowledge. Carefully complete each exercise recording the required information on the report sheets beginning on page 4. When complete, submit the reports sheets to the instructor to be graded.
Activity:
I. You have noticed that your heart rate seems to race when you physically exert yourself. You wonder if the human heart rate increases as the intensity of exercise increases. You can hypothesize that this is indeed the case.
A. State the observation.
B. What problem or question has been identified?
C. The hypothesis is
D. Experimentation: To obtain the necessary data, you must determine your heart rate at varying levels of physical exertion. You will first monitor your heart rate at rest to establish a base line. Lie down for at least five minutes, then determine your heart rate by monitoring your pulse rate. (Blood surges through arteries each time your heart beats.) On your report sheet, record your resting pulse rate in beats per minute. The step exercise will be used at varying levels of intensity. In this exercise you will step up one step, then step back down. Do this ten times in a one minute period. (Once every six seconds.) Quickly monitor your pulse in beats per minute. Record your pulse rate on the grid (graph) on the Report Sheet. Rest until your pulse rate nears your resting rate. Repeat the step exercise and pulse reading for: fifteen steps, twenty steps, twenty-five steps, thirty steps, thirty-five steps, and forty steps per minute. (If you are physically unable to perform the step exercise, substitute another mode of exertion which is measurable. Or let another person do the step test.) Summarize your results by plotting your heart rate against your exercise intensity on the graph provided.
E. Conclusion
Answer all the follow-up questions concerning this experiment.
This exercise should be reported on Report Sheets 1-2.
THE SCIENTIFIC METHOD Report Sheet 1
Student Name:
Date:
I.
A. Observation
B. Problem
C. Collected Information: (none for this illustration)
D. Hypothesis
E. Experiment
F. Conclusion
II. Use the following grid to make a graph to show your heart rate at each exercise intensity.
III. Answer the following questions
A. Interpret the graph in your own words.
THE SCIENTIFIC METHOD Report Sheet 2
Student Name:
B. Can we also conclude that:
1. The heart rate is directly proportional to the intensity of physical exertion? Why or why not?
2. That if we run this experiment on another family member the results and conclusion will be similar?
Why or why not?
3. That the graph for a highly conditioned athlete would look similar to your graph? Why or why not?
C. Could this test be repeated exactly by another researcher? Why is repeatability of experimentation important?
D. Is this test valid/reliable? Why or why not?
E. Design a better experiment which will yield results which are more reliable?
INTRODUCTION
Science has been described as a way of knowing. It emerges from man's curiosity about ourselves and the world around us. Seeking to understand seems to be one of our basic drives. We ask questions that arise from our observations of natural things; and we seek discovery of answers. Striving to reveal the secrets of nature, scientists have devised a method of getting at the truth or solving problems. This is called the scientific method. Actually, there are many methods but they all bear common features or rules.
Is the scientific method something that only scientists can use? Certainly not; its usefulness extends to all of us, even in our daily lives. For example, I can use it to find why my car will not start. Or, I can find out what foods give me a stomachache.
Despite what the scientist wants to find out and the exact procedure used, certain features of the scientific method are common. Scientists make observations that lead them to ask questions. They make educated guesses about possible answers, then devise ways to test their guesses. In its classical form the scientific method involves the following steps:
1. Observation and Stating of a Problem - Scientific investigations usually begin with an observation that stimulates a desire to know or understand. The scientist then states the problem as clearly and concisely as possible.
2. Collection of Pertinent Information - An attempt should be made to assemble the pertinent facts concerning the problem. The scientist seeks to tap into as much available information about the problem as possible. This information may come from the library, the worldwide web, colleagues, or from other available sources.
3. Formulation of a Hypothesis - Based on information assembled in step two above, a tentative explanation or hypothesis is advanced. Some call this an educated guess. This is a trial idea, a possible solution to the problem. A key feature of the hypothesis is that it can be tested or validated.
4. Testing of the Hypothesis - In this step the scientist designs and executes an experiment to test the validity of the hypothesis. The exact design of this test can vary greatly and depends upon the nature of the study and the creativity of the investigator. The experiment must be carefully planned and conducted with great precision. Scientists strive to eliminate all human and instrumental bias. Accurate records as quantifiable data must be kept of every phase of the experiment. Results of the experiment are gathered and analyzed. Many experiments consist of a control group and an experimental group. The experimental group is identical to the control group in every respect except one, called the variable. The one substance, situation, etc. that is being tested is varied. All other factors are kept constant in both the experimental group and the control group. Therefore, the control serves as the basis or standard by which it is determined if the one variable is responsible for any differences in results. A key feature of the experiment is that it must be repeatable. That is, other researchers must be able to repeat the experiment under the same conditions and achieve the same results.
5. Conclusion - When the experiment is complete, the researcher must evaluate the results in an effort to reach a conclusion. The conclusion either supports or fails to support the original hypothesis. In either case, knowledge is gained and the researcher moves on.
6. Publication of Results - While your personal use of the scientific method does not involve this step, it is vital to the scientist. This requires publication, in appropriate scientific literature, of a detailed report of the problem, the hypothesis, all experimental methods and results, and the conclusions reached by the investigator. This allows other scientists to repeat the investigation if they choose, as a way of confirming the validity of the study.
LABORATORY EXERCISE PROCEDURE
Use the indicated steps of the scientific method with each of the following three (3) exercises. These exercises are designed to provide some experience using the scientific method as a way to acquire knowledge. Carefully complete each exercise recording the required information on the report sheets beginning on page 4. When complete, submit the reports sheets to the instructor to be graded.
Activity:
I. You have noticed that your heart rate seems to race when you physically exert yourself. You wonder if the human heart rate increases as the intensity of exercise increases. You can hypothesize that this is indeed the case.
A. State the observation.
B. What problem or question has been identified?
C. The hypothesis is
D. Experimentation: To obtain the necessary data, you must determine your heart rate at varying levels of physical exertion. You will first monitor your heart rate at rest to establish a base line. Lie down for at least five minutes, then determine your heart rate by monitoring your pulse rate. (Blood surges through arteries each time your heart beats.) On your report sheet, record your resting pulse rate in beats per minute. The step exercise will be used at varying levels of intensity. In this exercise you will step up one step, then step back down. Do this ten times in a one minute period. (Once every six seconds.) Quickly monitor your pulse in beats per minute. Record your pulse rate on the grid (graph) on the Report Sheet. Rest until your pulse rate nears your resting rate. Repeat the step exercise and pulse reading for: fifteen steps, twenty steps, twenty-five steps, thirty steps, thirty-five steps, and forty steps per minute. (If you are physically unable to perform the step exercise, substitute another mode of exertion which is measurable. Or let another person do the step test.) Summarize your results by plotting your heart rate against your exercise intensity on the graph provided.
E. Conclusion
Answer all the follow-up questions concerning this experiment.
This exercise should be reported on Report Sheets 1-2.
THE SCIENTIFIC METHOD Report Sheet 1
Student Name:
Date:
I.
A. Observation
B. Problem
C. Collected Information: (none for this illustration)
D. Hypothesis
E. Experiment
F. Conclusion
II. Use the following grid to make a graph to show your heart rate at each exercise intensity.
III. Answer the following questions
A. Interpret the graph in your own words.
THE SCIENTIFIC METHOD Report Sheet 2
Student Name:
B. Can we also conclude that:
1. The heart rate is directly proportional to the intensity of physical exertion? Why or why not?
2. That if we run this experiment on another family member the results and conclusion will be similar?
Why or why not?
3. That the graph for a highly conditioned athlete would look similar to your graph? Why or why not?
C. Could this test be repeated exactly by another researcher? Why is repeatability of experimentation important?
D. Is this test valid/reliable? Why or why not?
E. Design a better experiment which will yield results which are more reliable?
viernes, 26 de junio de 2009
Scientific method. Exercises
Scientific Method Exercise
Choosing Hypotheses
1. A scientist has 12 plants. All the plants were the same kind and about the same size. He put three plants on a window sill inside a room. He put another three plants in a closet without a light. He put another three more plants outside on the ground. He put his last three plants outside too, but covered them with paper bags that had wholes punched in them for air. All the plants were given good soil and enough water. The plants on the window sill and the plants outside in the open grew well. The plants outside in the bags turned yellow and grew badly. The plants in the closet died. Which of the following is the best hypothesis based on the facts?
a) Green plants turn yellow due to disease.
b) Green plants don’t live for very long.
c) Green plants need light to grow.
d) Green plants cannot grow inside
e) Green plants grow well in closets.
2. Louis Pasteur, a famous scientist who lived over 100 years ago, made an important hypothesis about a certain germ called bacteria. He noticed that bacteria grew quickly in open jars of liquid, like chicken soup. Bacteria also grew in jars of soup that were sealed tightly so that no air could get in. However they didn’t grow in soup that was sealed tightly in a jaw, then boiled and kept sealed after it cooled. When was Pasteur’s correct hypothesis?
a) Bacteria cannot grow in jars.
b) Bacteria must have air to survive
c) Bacteria only grow in chicken soup
d) Bacteria can be killed by boiling.
e) Bacteria can live in boiling liquids.
Errors in experiments
Tell what is wrong with each of these experiments. Choose from this list:
· Not enough subjects
· Subjects were not similar.
· Conditions were not kept the same
· The experiment was not reproduced.
1. A gardener wanted to know if XYZ fertilizer would be good for this vegetable. He fertilized all his bean plants with XYZ but didn’t put any fertilizer on his pepper plants. His beans didn’t do well at all, but he got a good crop of peppers. He concluded that XYZ fertilizer was no good.
2. Alice Larsen wanted to see if a new premium gasoline would give her more kilometers to the liter. She filled her car with the new gas and went on a long trip. When she figured her mileage, she discovered that she has gone 40 Km farther on this tank of gas then she went on a tanks of regular gas when she was driving around town as usual. She decided to buy the premium gas for then on to get better mileage.
3. A molding machine in a factory was not working very well. About a third of the time, the plastic squirt guns that it was making come out with a flaw in the handle. The repair mechanic adjusted the stamping pressure. Then she ran one gun through. It came out just fine, so she figured she had solved the problem.
Choosing Hypotheses
1. A scientist has 12 plants. All the plants were the same kind and about the same size. He put three plants on a window sill inside a room. He put another three plants in a closet without a light. He put another three more plants outside on the ground. He put his last three plants outside too, but covered them with paper bags that had wholes punched in them for air. All the plants were given good soil and enough water. The plants on the window sill and the plants outside in the open grew well. The plants outside in the bags turned yellow and grew badly. The plants in the closet died. Which of the following is the best hypothesis based on the facts?
a) Green plants turn yellow due to disease.
b) Green plants don’t live for very long.
c) Green plants need light to grow.
d) Green plants cannot grow inside
e) Green plants grow well in closets.
2. Louis Pasteur, a famous scientist who lived over 100 years ago, made an important hypothesis about a certain germ called bacteria. He noticed that bacteria grew quickly in open jars of liquid, like chicken soup. Bacteria also grew in jars of soup that were sealed tightly so that no air could get in. However they didn’t grow in soup that was sealed tightly in a jaw, then boiled and kept sealed after it cooled. When was Pasteur’s correct hypothesis?
a) Bacteria cannot grow in jars.
b) Bacteria must have air to survive
c) Bacteria only grow in chicken soup
d) Bacteria can be killed by boiling.
e) Bacteria can live in boiling liquids.
Errors in experiments
Tell what is wrong with each of these experiments. Choose from this list:
· Not enough subjects
· Subjects were not similar.
· Conditions were not kept the same
· The experiment was not reproduced.
1. A gardener wanted to know if XYZ fertilizer would be good for this vegetable. He fertilized all his bean plants with XYZ but didn’t put any fertilizer on his pepper plants. His beans didn’t do well at all, but he got a good crop of peppers. He concluded that XYZ fertilizer was no good.
2. Alice Larsen wanted to see if a new premium gasoline would give her more kilometers to the liter. She filled her car with the new gas and went on a long trip. When she figured her mileage, she discovered that she has gone 40 Km farther on this tank of gas then she went on a tanks of regular gas when she was driving around town as usual. She decided to buy the premium gas for then on to get better mileage.
3. A molding machine in a factory was not working very well. About a third of the time, the plastic squirt guns that it was making come out with a flaw in the handle. The repair mechanic adjusted the stamping pressure. Then she ran one gun through. It came out just fine, so she figured she had solved the problem.
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