Friday, July 23, 2010
Wednesday, July 21, 2010
Global Dairy Top-20
Global Dairy Top-20: "Brazil is tipped for the Top-20 next year, assuming successful completion of the new conglomerate made up of Itamb�, Centro Leche, Confepar, Mineiras Cemil and Mines Milk. Mexico’s Grupo Lala is also bubbling under, following its acquisition of National Dairy Holdings last year.
Fragmentation in the German market and the slow pace of consolidation between Nordmilch and Humana Milchunion has knocked Germany out of the Top-20 entirely this year. Bel, the French producer of ‘La Vache qui rit’ came in at number 19 but Mark Voorbergen expects it may lose its position once compatriots Entremont and Sodiaal complete their merger.
Although Japanese dairy consumption has probably reached its peak at around 60 litres per person per year, Meiji Dairies (11) and Morinaga (14) were able to improve their position over competitors thanks to the relatively stable yen and local prices."
Fragmentation in the German market and the slow pace of consolidation between Nordmilch and Humana Milchunion has knocked Germany out of the Top-20 entirely this year. Bel, the French producer of ‘La Vache qui rit’ came in at number 19 but Mark Voorbergen expects it may lose its position once compatriots Entremont and Sodiaal complete their merger.
Although Japanese dairy consumption has probably reached its peak at around 60 litres per person per year, Meiji Dairies (11) and Morinaga (14) were able to improve their position over competitors thanks to the relatively stable yen and local prices."
Global Dairy Top-20
Global Dairy Top-20: "Supply and demand
Putting consumption into perspective, Mark contrasts the 300 litres of dairy products consumed per person per year in the Netherlands with the current 20 litres per person per year in China.
“We expect the Chinese market to grow along the same lines as Japan or South Korea, from zero levels five years ago to a maximum of 50 litres per person per year.”
But volume growth is only happening in developing regions like China, South East Asia and selected markets in the Middle East, Africa and Latin America. For the developed markets of Europe, the USA and New Zealand, the main growth challenge is to introduce new characteristics – often related to health and convenience - to standard dairy products that the consumer is willing to pay for."
Putting consumption into perspective, Mark contrasts the 300 litres of dairy products consumed per person per year in the Netherlands with the current 20 litres per person per year in China.
“We expect the Chinese market to grow along the same lines as Japan or South Korea, from zero levels five years ago to a maximum of 50 litres per person per year.”
But volume growth is only happening in developing regions like China, South East Asia and selected markets in the Middle East, Africa and Latin America. For the developed markets of Europe, the USA and New Zealand, the main growth challenge is to introduce new characteristics – often related to health and convenience - to standard dairy products that the consumer is willing to pay for."
Global Dairy Top-20
Global Dairy Top-20: "Global Dairy Top-20
Rabobank's new Global Dairy Top-20 shows the recent growth of Japan and China in the world dairy sector.
The Top-10 is still headed by Nestle, and dominated by players from the mature markets of Europe and the US.
However Japanese contender Meiji Dairies moved up three places to number 11, and Yili from China shot into the rankings for the first time at number 17.
Changing diets and strength in numbers are key to understanding the growth of demand in the Asian markets, according to Mark Voorbergen of Rabobank’s Food & Agribusiness Research and Advisory."
Rabobank's new Global Dairy Top-20 shows the recent growth of Japan and China in the world dairy sector.
The Top-10 is still headed by Nestle, and dominated by players from the mature markets of Europe and the US.
However Japanese contender Meiji Dairies moved up three places to number 11, and Yili from China shot into the rankings for the first time at number 17.
Changing diets and strength in numbers are key to understanding the growth of demand in the Asian markets, according to Mark Voorbergen of Rabobank’s Food & Agribusiness Research and Advisory."
RCVS Online / Latest News / RCVS Day - changes and celebrations
RCVS Online / Latest News / RCVS Day - changes and celebrations: "Discussing the “responsive, adaptive and innovative” activities of the College against this backdrop, he made mention of the development of the veterinary nursing profession, the review of the Practice Standards Scheme and plans for the consideration of dispute resolution, and of a Health Protocol to deal humanely with vets whose ability is impaired by ill-health or addiction, while protecting the public.
He also stressed the need for legislative action to vary the composition of the Disciplinary Committee to ensure it was fit for purpose – now a “pressing need”.
Incoming President Peter Jinman thanked Sandy Trees for the “considerable time and effort” he had spent on behalf of the profession and the public as President of the College.
Peter said that he looked forward to his own presidency with a mixture of pleasure and sadness, as the commitment necessitated him retiring from practice after 34 years. He echoed Sandy Trees’ view that a one-year presidency was too short.
Looking forward, he sought to “steer the College on a path that will ensure the provision of an educated, regulated body of people called veterinary surgeons who are, in the words of Section 14 of the Sale of Goods Act 1979, ‘fit for purpose’.”"
He also stressed the need for legislative action to vary the composition of the Disciplinary Committee to ensure it was fit for purpose – now a “pressing need”.
Incoming President Peter Jinman thanked Sandy Trees for the “considerable time and effort” he had spent on behalf of the profession and the public as President of the College.
Peter said that he looked forward to his own presidency with a mixture of pleasure and sadness, as the commitment necessitated him retiring from practice after 34 years. He echoed Sandy Trees’ view that a one-year presidency was too short.
Looking forward, he sought to “steer the College on a path that will ensure the provision of an educated, regulated body of people called veterinary surgeons who are, in the words of Section 14 of the Sale of Goods Act 1979, ‘fit for purpose’.”"
RCVS Online / Latest News / RCVS Day - changes and celebrations
RCVS Online / Latest News / RCVS Day - changes and celebrations: "Guest speaker at the event was RCVS Fellow and veterinary polymath Roger Short, who gave a talk entitled: “The way ahead for the veterinary profession in a warming world.”
In an entertaining and at times controversial speech, Roger outlined his view that, as members of the only medical profession capable of thinking laterally and considering man as just another species of animal, it was incumbent upon veterinary surgeons to tell some home truths about the impact of global population growth on biodiversity and global sustainability.
Direct action was required, he felt, propounding the view that all women should take the contraceptive pill for the benefit of their own health, as well as that of the future of the planet."
In an entertaining and at times controversial speech, Roger outlined his view that, as members of the only medical profession capable of thinking laterally and considering man as just another species of animal, it was incumbent upon veterinary surgeons to tell some home truths about the impact of global population growth on biodiversity and global sustainability.
Direct action was required, he felt, propounding the view that all women should take the contraceptive pill for the benefit of their own health, as well as that of the future of the planet."
RCVS Online / Latest News / RCVS Day - changes and celebrations
RCVS Online / Latest News / RCVS Day - changes and celebrations: "Guest speaker at the event was RCVS Fellow and veterinary polymath Roger Short, who gave a talk entitled: “The way ahead for the veterinary profession in a warming world.”
In an entertaining and at times controversial speech, Roger outlined his view that, as members of the only medical profession capable of thinking laterally and considering man as just another species of animal, it was incumbent upon veterinary surgeons to tell some home truths about the impact of global population growth on biodiversity and global sustainability.
Direct action was required, he felt, propounding the view that all women should take the contraceptive pill for the benefit of their own health, as well as that of the future of the planet."
In an entertaining and at times controversial speech, Roger outlined his view that, as members of the only medical profession capable of thinking laterally and considering man as just another species of animal, it was incumbent upon veterinary surgeons to tell some home truths about the impact of global population growth on biodiversity and global sustainability.
Direct action was required, he felt, propounding the view that all women should take the contraceptive pill for the benefit of their own health, as well as that of the future of the planet."
RCVS Online / Latest News / RCVS Day - changes and celebrations
RCVS Online / Latest News / RCVS Day - changes and celebrations: "Guest speaker at the event was RCVS Fellow and veterinary polymath Roger Short, who gave a talk entitled: “The way ahead for the veterinary profession in a warming world.”
In an entertaining and at times controversial speech, Roger outlined his view that, as members of the only medical profession capable of thinking laterally and considering man as just another species of animal, it was incumbent upon veterinary surgeons to tell some home truths about the impact of global population growth on biodiversity and global sustainability.
Direct action was required, he felt, propounding the view that all women should take the contraceptive pill for the benefit of their own health, as well as that of the future of the planet."
In an entertaining and at times controversial speech, Roger outlined his view that, as members of the only medical profession capable of thinking laterally and considering man as just another species of animal, it was incumbent upon veterinary surgeons to tell some home truths about the impact of global population growth on biodiversity and global sustainability.
Direct action was required, he felt, propounding the view that all women should take the contraceptive pill for the benefit of their own health, as well as that of the future of the planet."
Looking for support in your area? for HIV
aidsmap.com :: HIV basics - Looking for support in your area?: "If you’re worried you might have HIV, or if you have been diagnosed with HIV, it can really help to talk to someone about your situation.
As well as doctors and other medical professionals, there are lots of community organisations that offer information, support and advice.
You can use our E-atlas to find different types of support, as well as medical services."
As well as doctors and other medical professionals, there are lots of community organisations that offer information, support and advice.
You can use our E-atlas to find different types of support, as well as medical services."
Looking for support in your area? for HIV
aidsmap.com :: HIV basics - Looking for support in your area?: "If you’re worried you might have HIV, or if you have been diagnosed with HIV, it can really help to talk to someone about your situation.
As well as doctors and other medical professionals, there are lots of community organisations that offer information, support and advice.
You can use our E-atlas to find different types of support, as well as medical services."
As well as doctors and other medical professionals, there are lots of community organisations that offer information, support and advice.
You can use our E-atlas to find different types of support, as well as medical services."
aidsmap.com :: HIV basics - Treatment
aidsmap.com :: HIV basics - Treatment: "All medicines can cause side-effects, and this includes those used to treat HIV. But it’s good to know that many people find modern HIV treatment easy to take.
Anti-HIV drugs can cause both short-term and long-term side-effects.
Common side-effects you might have when you first start a treatment are diarrhoea, feeling or being sick, and headache. Some drugs can also cause problems sleeping, including vivid dreams, a feeling of being ‘spaced out’ or depression.
Most people find that these side-effects lessen or go away completely after a couple of weeks.
A few anti-HIV drugs can cause an allergic reaction. You should be screened for risk factors before taking any of these drugs, and then warned about possible symptoms. If you do then have any of those symptoms, you should seek medical advice immediately."
Anti-HIV drugs can cause both short-term and long-term side-effects.
Common side-effects you might have when you first start a treatment are diarrhoea, feeling or being sick, and headache. Some drugs can also cause problems sleeping, including vivid dreams, a feeling of being ‘spaced out’ or depression.
Most people find that these side-effects lessen or go away completely after a couple of weeks.
A few anti-HIV drugs can cause an allergic reaction. You should be screened for risk factors before taking any of these drugs, and then warned about possible symptoms. If you do then have any of those symptoms, you should seek medical advice immediately."
HIV basics - Treatment
aidsmap.com :: HIV basics - Treatment: "Treatment for HIV involves taking a combination of anti-HIV drugs. This treatment has a very powerful anti-HIV effect and stops the virus from reproducing.
This allows the immune system to strengthen and fight infections effectively.
To get the most benefit from your HIV treatment, you need to take it properly. This is often called ‘adherence’."
This allows the immune system to strengthen and fight infections effectively.
To get the most benefit from your HIV treatment, you need to take it properly. This is often called ‘adherence’."
HIV basics - Transmission11
aidsmap.com :: HIV basics - Transmission: "Many people who are HIV-negative are in successful, loving, and intimate relationships with an HIV-positive partner.
Modern HIV treatment and care can significantly improve your partner’s health and life expectancy. Many people with HIV can expect to have a near-normal lifespan. There’s a lot of support available to help you both deal with the stresses and strains related to HIV that may arise in your relationship.
It may be reassuring to know that you can stay HIV-negative. It’s completely safe to kiss and hug your partner. What’s more, many couples have intimate and fulfilling sex lives without passing on HIV"
Modern HIV treatment and care can significantly improve your partner’s health and life expectancy. Many people with HIV can expect to have a near-normal lifespan. There’s a lot of support available to help you both deal with the stresses and strains related to HIV that may arise in your relationship.
It may be reassuring to know that you can stay HIV-negative. It’s completely safe to kiss and hug your partner. What’s more, many couples have intimate and fulfilling sex lives without passing on HIV"
HIV basics - Transmission11
aidsmap.com :: HIV basics - Transmission: "Many people who are HIV-negative are in successful, loving, and intimate relationships with an HIV-positive partner.
Modern HIV treatment and care can significantly improve your partner’s health and life expectancy. Many people with HIV can expect to have a near-normal lifespan. There’s a lot of support available to help you both deal with the stresses and strains related to HIV that may arise in your relationship.
It may be reassuring to know that you can stay HIV-negative. It’s completely safe to kiss and hug your partner. What’s more, many couples have intimate and fulfilling sex lives without passing on HIV"
Modern HIV treatment and care can significantly improve your partner’s health and life expectancy. Many people with HIV can expect to have a near-normal lifespan. There’s a lot of support available to help you both deal with the stresses and strains related to HIV that may arise in your relationship.
It may be reassuring to know that you can stay HIV-negative. It’s completely safe to kiss and hug your partner. What’s more, many couples have intimate and fulfilling sex lives without passing on HIV"
HIV - Transmission
aidsmap.com :: HIV basics - Transmission: "You cannot get HIV from kissing, by hugging, or by shaking hands with somebody with HIV – or any other normal social contact.
Nor can you get HIV by being in the same place as someone with HIV, or by sharing household items such as crockery, cutlery, or bed linen.
HIV is not passed on by spitting, sneezing or coughing."
Nor can you get HIV by being in the same place as someone with HIV, or by sharing household items such as crockery, cutlery, or bed linen.
HIV is not passed on by spitting, sneezing or coughing."
HIV - Transmission
aidsmap.com :: HIV basics - Transmission: "You cannot get HIV from kissing, by hugging, or by shaking hands with somebody with HIV – or any other normal social contact.
Nor can you get HIV by being in the same place as someone with HIV, or by sharing household items such as crockery, cutlery, or bed linen.
HIV is not passed on by spitting, sneezing or coughing."
Nor can you get HIV by being in the same place as someone with HIV, or by sharing household items such as crockery, cutlery, or bed linen.
HIV is not passed on by spitting, sneezing or coughing."
HIV- Transmission
aidsmap.com :: HIV basics - Transmission: "HIV is found in body fluids. It is present in enough quantity to be infectious in genital fluids, blood and breast milk.
The main ways in which HIV is passed on are unprotected anal, vaginal and oral sex, by sharing injecting equipment, and from a mother to her baby during pregnancy, birth or breastfeeding.
Condoms provide excellent protection against HIV transmission during sex.
If you inject drugs, you can reduce the risk of HIV and other infections by not sharing needles or other injecting equipment.
With the right treatment and care during pregnancy and birth, and by not breastfeeding, it’s nearly always possible to prevent mother-to-child transmission of HIV."
The main ways in which HIV is passed on are unprotected anal, vaginal and oral sex, by sharing injecting equipment, and from a mother to her baby during pregnancy, birth or breastfeeding.
Condoms provide excellent protection against HIV transmission during sex.
If you inject drugs, you can reduce the risk of HIV and other infections by not sharing needles or other injecting equipment.
With the right treatment and care during pregnancy and birth, and by not breastfeeding, it’s nearly always possible to prevent mother-to-child transmission of HIV."
HIV- Transmission
aidsmap.com :: HIV basics - Transmission: "HIV is found in body fluids. It is present in enough quantity to be infectious in genital fluids, blood and breast milk.
The main ways in which HIV is passed on are unprotected anal, vaginal and oral sex, by sharing injecting equipment, and from a mother to her baby during pregnancy, birth or breastfeeding.
Condoms provide excellent protection against HIV transmission during sex.
If you inject drugs, you can reduce the risk of HIV and other infections by not sharing needles or other injecting equipment.
With the right treatment and care during pregnancy and birth, and by not breastfeeding, it’s nearly always possible to prevent mother-to-child transmission of HIV."
The main ways in which HIV is passed on are unprotected anal, vaginal and oral sex, by sharing injecting equipment, and from a mother to her baby during pregnancy, birth or breastfeeding.
Condoms provide excellent protection against HIV transmission during sex.
If you inject drugs, you can reduce the risk of HIV and other infections by not sharing needles or other injecting equipment.
With the right treatment and care during pregnancy and birth, and by not breastfeeding, it’s nearly always possible to prevent mother-to-child transmission of HIV."
aidsmap.com :: HIV basics - Testing
aidsmap.com :: HIV basics - Testing: "There are several different types of HIV tests. Often a small sample of blood is taken and analysed in a laboratory. Other tests give an initial rapid result using finger-prick blood, or even saliva. It’s often possible to get a test result the same day.
The tests used today can usually tell if a person has HIV within two or three weeks of their infection. In the past you might have had to wait three months to be certain that your test result is accurate.
It’s a good idea to talk to the person giving you the HIV test if you have any questions about it."
The tests used today can usually tell if a person has HIV within two or three weeks of their infection. In the past you might have had to wait three months to be certain that your test result is accurate.
It’s a good idea to talk to the person giving you the HIV test if you have any questions about it."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "Tuberculosis, or TB, is one of the most common AIDS-defining illnesses. In many cases, HIV was only diagnosed because people became ill with TB. Worldwide, TB is the leading cause of illness and death in people with HIV.
TB is passed on through infected saliva from the coughs or sneezes of an infected person.� Once infected, you may not have any symptoms of illness for a very long time.
TB causes fever, coughing, chest pain and weight loss. It mostly affects the lungs but can affect other parts of the body.
TB is treated with a combination of antibiotics, which is normally taken for six months. In some cases, it may be necessary for treatment to last longer."
TB is passed on through infected saliva from the coughs or sneezes of an infected person.� Once infected, you may not have any symptoms of illness for a very long time.
TB causes fever, coughing, chest pain and weight loss. It mostly affects the lungs but can affect other parts of the body.
TB is treated with a combination of antibiotics, which is normally taken for six months. In some cases, it may be necessary for treatment to last longer."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "Tuberculosis and hepatitis are two conditions that are very common in people who also have HIV. These are diseases that can have an effect on HIV and can also be affected by HIV. They are sometimes referred to as co-infections.
Hepatitis B and C are transmitted in similar ways to HIV: by contact with infected body fluids like blood, semen and vaginal fluid, and from a mother to her baby during pregnancy or delivery.
Both these types of hepatitis can cause serious liver damage, and liver disease is a major cause of serious illness and death in co-infected patients.
There is a vaccine against hepatitis B. It works well in people with HIV, and everyone who is HIV-positive should receive it.
There is no vaccine against hepatitis C. Hepatitis C can be cured with treatment which needs to be taken for up to a year. The best results are seen if treatment is provided soon after a person is infected with the virus."
Hepatitis B and C are transmitted in similar ways to HIV: by contact with infected body fluids like blood, semen and vaginal fluid, and from a mother to her baby during pregnancy or delivery.
Both these types of hepatitis can cause serious liver damage, and liver disease is a major cause of serious illness and death in co-infected patients.
There is a vaccine against hepatitis B. It works well in people with HIV, and everyone who is HIV-positive should receive it.
There is no vaccine against hepatitis C. Hepatitis C can be cured with treatment which needs to be taken for up to a year. The best results are seen if treatment is provided soon after a person is infected with the virus."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "In 1996, triple-drug HIV treatment was introduced. This treatment was able to reduce the amount of virus in the blood and allow the immune system to strengthen. Thanks to this treatment, the number of AIDS deaths fell dramatically in countries where treatment was widely available.
However, HIV was spreading rapidly in some of the world’s poorest countries, especially in southern Africa, and wider access to HIV treatment in these countries is only now starting to become a reality.
The early HIV treatment combinations were difficult to take and many caused unpleasant and long-term side-effects.
More powerful, easier-to-take and safer drugs gradually became available. Thanks to these, and other improvements in HIV care, doctors have become increasingly hopeful that many people with HIV will be able to live a near-normal lifespan.
Nevertheless, HIV continues to spread. The infection is spreading rapidly in Eastern Europe, China, India and south-east Asia.
HIV is now firmly established as one of the leading health concerns of the 21st century, and one of the most significant causes of illness and death in human history."
However, HIV was spreading rapidly in some of the world’s poorest countries, especially in southern Africa, and wider access to HIV treatment in these countries is only now starting to become a reality.
The early HIV treatment combinations were difficult to take and many caused unpleasant and long-term side-effects.
More powerful, easier-to-take and safer drugs gradually became available. Thanks to these, and other improvements in HIV care, doctors have become increasingly hopeful that many people with HIV will be able to live a near-normal lifespan.
Nevertheless, HIV continues to spread. The infection is spreading rapidly in Eastern Europe, China, India and south-east Asia.
HIV is now firmly established as one of the leading health concerns of the 21st century, and one of the most significant causes of illness and death in human history."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "Other drugs were developed, but it became clear that treatment with one drug alone did not work well in the long term.
Treatment with two anti-HIV drugs was shown to have more benefit, but the real breakthrough came with development of new anti-HIV drugs that worked against the virus in a number of different ways.
In 1996, triple-drug HIV treatment was introduced. This treatment was able to reduce the amount of virus in the blood and allow the immune system to strengthen. Thanks to this treatment, the number of AIDS deaths fell dramatically in countries where treatment was widely available.
However, HIV was spreading rapidly in some of the world’s poorest countries, especially in southern Africa, and wider access to HIV treatment in these countries is only now starting to become a reality.
The early HIV treatment combinations were difficult to take and many caused unpleasant and long-term side-effects."
Treatment with two anti-HIV drugs was shown to have more benefit, but the real breakthrough came with development of new anti-HIV drugs that worked against the virus in a number of different ways.
In 1996, triple-drug HIV treatment was introduced. This treatment was able to reduce the amount of virus in the blood and allow the immune system to strengthen. Thanks to this treatment, the number of AIDS deaths fell dramatically in countries where treatment was widely available.
However, HIV was spreading rapidly in some of the world’s poorest countries, especially in southern Africa, and wider access to HIV treatment in these countries is only now starting to become a reality.
The early HIV treatment combinations were difficult to take and many caused unpleasant and long-term side-effects."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "Untreated HIV eventually leads to AIDS. The first cluster of AIDS cases were reported in New York and San Francisco in 1981. Doctors noticed that gay men were becoming ill with a rare form of pneumonia (PCP) and a cancer called Kaposi’s sarcoma.
Researchers worked out that these men had an underlying infection, and that it was likely to be sexually transmitted and blood-borne.
Further cases of AIDS were soon reported in gay men in other countries, including the UK. But it quickly became apparent that AIDS was affecting other groups as well.
In 1985, the virus that is now known as HIV was identified.
Even before HIV was discovered, safer sex and safer drug use had become established ways of reducing the risk of the illness.
As the virus spread around the world and deaths mounted, research went into finding a cure or vaccine. The first drug found to have an effect against HIV was AZT."
Researchers worked out that these men had an underlying infection, and that it was likely to be sexually transmitted and blood-borne.
Further cases of AIDS were soon reported in gay men in other countries, including the UK. But it quickly became apparent that AIDS was affecting other groups as well.
In 1985, the virus that is now known as HIV was identified.
Even before HIV was discovered, safer sex and safer drug use had become established ways of reducing the risk of the illness.
As the virus spread around the world and deaths mounted, research went into finding a cure or vaccine. The first drug found to have an effect against HIV was AZT."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "HIV is very similar to a virus called SIV (simian immunodeficiency virus), which is found in monkeys.
There’s now good evidence that it jumped species from chimpanzees to man in the early 20th century."
There’s now good evidence that it jumped species from chimpanzees to man in the early 20th century."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "This will depend both on your own and the other person’s circumstances, needs, and character.
But making it clear that you’re there to offer support, not judging, and listening, are often good places to start.
Learning about HIV, its effects and treatment may help you to understand the experiences of your loved one, and to be able to discuss their experience or options.
Finding out about other sources of support – both for the person with HIV and yourself – is also likely to be a good idea. There are many organisations that provide information, advice and support across the world."
But making it clear that you’re there to offer support, not judging, and listening, are often good places to start.
Learning about HIV, its effects and treatment may help you to understand the experiences of your loved one, and to be able to discuss their experience or options.
Finding out about other sources of support – both for the person with HIV and yourself – is also likely to be a good idea. There are many organisations that provide information, advice and support across the world."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "With modern HIV treatment, many people with HIV are living long and healthy lives. In fact, some doctors are hopeful that many people with HIV will live a near-normal life expectancy.
A lot of effort is going into making effective HIV treatment available to everyone who needs it. However, this is not always possible in some parts of the world. Without treatment, people with HIV will almost always eventually become ill, and their lives may be shortened.
Your best chance of staying well is to start treatment at the right time. To do this you need to know you have HIV. Many of the people who die from HIV-related illnesses in countries where treatment is easily available were diagnosed very late, often not until they were already very ill."
A lot of effort is going into making effective HIV treatment available to everyone who needs it. However, this is not always possible in some parts of the world. Without treatment, people with HIV will almost always eventually become ill, and their lives may be shortened.
Your best chance of staying well is to start treatment at the right time. To do this you need to know you have HIV. Many of the people who die from HIV-related illnesses in countries where treatment is easily available were diagnosed very late, often not until they were already very ill."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "It’s difficult to say for sure how many people have HIV, as often people do not realise they have been infected and may live with HIV for some time before they are diagnosed.
The United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) produce figures for the global epidemic and also for individual countries, based on numbers collected by the health services in each country.
You can find out more about HIV in each country of the world by visiting our E-atlas."
The United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) produce figures for the global epidemic and also for individual countries, based on numbers collected by the health services in each country.
You can find out more about HIV in each country of the world by visiting our E-atlas."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "The United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) released their annual figures for World AIDS Day in 2009. They said that at the end of 2008 there were 33.4 million people living with HIV. In 2008 there were 2.7 million new infections and 2 million HIV-related deaths.
Their report also showed that, at the end of 2008, 4 million people were receiving antiretroviral drugs."
Their report also showed that, at the end of 2008, 4 million people were receiving antiretroviral drugs."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "If you’ve had unprotected sex and notice these symptoms about two weeks later, you might want to consider having an HIV test.
After this initial illness, it’s not uncommon for people to live with HIV and not to have any symptoms at all. But the virus will still be causing damage to the immune system, and without treatment most people with HIV will eventually become ill because of it.
HIV-related illnesses can cause a wide range of symptoms. These can include fevers and night sweats, a high temperature, a cough that won’t go away, unexplained weight loss, severe diarrhoea, bad headaches, or persistent mouth and skin problems. Of course, these can all have other causes."
After this initial illness, it’s not uncommon for people to live with HIV and not to have any symptoms at all. But the virus will still be causing damage to the immune system, and without treatment most people with HIV will eventually become ill because of it.
HIV-related illnesses can cause a wide range of symptoms. These can include fevers and night sweats, a high temperature, a cough that won’t go away, unexplained weight loss, severe diarrhoea, bad headaches, or persistent mouth and skin problems. Of course, these can all have other causes."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "This varies from person to person. The only way to be sure if you have been infected with HIV is to have an HIV test. You cannot tell from symptoms alone.
If you have HIV, it’s very important that it’s diagnosed for the best chance of getting treatment and care, and of staying well
Many people have an illness, often called a ‘seroconversion’ illness, soon after they are infected with HIV. Typical symptoms include a fever, sore throat, headache, aches and pains, and a blotchy red rash.
In some people this illness is so mild that it passes without being noticed. Some people mistake it for the flu, but for some people it is more severe and they may need to see a doctor. However, because the symptoms are similar to symptoms of many other conditions, HIV might not be diagnosed at the time."
If you have HIV, it’s very important that it’s diagnosed for the best chance of getting treatment and care, and of staying well
Many people have an illness, often called a ‘seroconversion’ illness, soon after they are infected with HIV. Typical symptoms include a fever, sore throat, headache, aches and pains, and a blotchy red rash.
In some people this illness is so mild that it passes without being noticed. Some people mistake it for the flu, but for some people it is more severe and they may need to see a doctor. However, because the symptoms are similar to symptoms of many other conditions, HIV might not be diagnosed at the time."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "An HIV test can tell if you have become infected with HIV. HIV tests are extremely accurate.
Modern tests can tell if you’ve been infected with HIV very soon after exposure to the virus – normally within two or three weeks.
If you have HIV, it’s very important that it’s diagnosed. This will give you the best chance of getting the treatment and care you need to stay well."
Modern tests can tell if you’ve been infected with HIV very soon after exposure to the virus – normally within two or three weeks.
If you have HIV, it’s very important that it’s diagnosed. This will give you the best chance of getting the treatment and care you need to stay well."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "AIDS is the name used to describe a combination of potentially life-threatening infections and cancers that can develop in people who have HIV.
Over time, infection with HIV damages the immune system, This means that the body cannot fight off a number of serious infections and cancers, which are sometimes called ‘AIDS-defining’.
Just because you are diagnosed with an AIDS-defining illness doesn’t mean that you are going to die. Many of these illnesses can be cured or managed.
Treatment with combinations of anti-HV drugs can keep the immune system strong, and because of this the number of people who are diagnosed with AIDS has fallen. Thanks to effective HIV treatment, many people who developed AIDS are now very well and can look forward to a long and healthy life."
Over time, infection with HIV damages the immune system, This means that the body cannot fight off a number of serious infections and cancers, which are sometimes called ‘AIDS-defining’.
Just because you are diagnosed with an AIDS-defining illness doesn’t mean that you are going to die. Many of these illnesses can be cured or managed.
Treatment with combinations of anti-HV drugs can keep the immune system strong, and because of this the number of people who are diagnosed with AIDS has fallen. Thanks to effective HIV treatment, many people who developed AIDS are now very well and can look forward to a long and healthy life."
aidsmap.com :: HIV basics - HIV & AIDS
aidsmap.com :: HIV basics - HIV & AIDS: "HIV stands for human immunodeficiency virus.
This particular virus was discovered in the mid 1980s and belongs to a group of viruses called ‘retroviruses’.
HIV attacks the immune system, and gradually causes damage. This can mean that a person infected with HIV is at risk of developing some serious infections and cancers that a healthy immune system can fight off. When a person develops certain illnesses and cancers, they are said to have developed AIDS.
A test can tell if you have HIV. If you do, this is described as being HIV-positive.
There is no cure for HIV. However, there are more than 20 anti-HIV drugs, and treatment with a combination of these drugs can mean a longer and healthy life.
HIV is present in blood, genital fluids and breast milk.
The main ways HIV can be passed on to someone else are during unprotected sex, by sharing injecting equipment, and from a mother to her baby during pregnancy, birth or through breastfeeding. But there are ways of preventing HIV infection in all of these situations."
This particular virus was discovered in the mid 1980s and belongs to a group of viruses called ‘retroviruses’.
HIV attacks the immune system, and gradually causes damage. This can mean that a person infected with HIV is at risk of developing some serious infections and cancers that a healthy immune system can fight off. When a person develops certain illnesses and cancers, they are said to have developed AIDS.
A test can tell if you have HIV. If you do, this is described as being HIV-positive.
There is no cure for HIV. However, there are more than 20 anti-HIV drugs, and treatment with a combination of these drugs can mean a longer and healthy life.
HIV is present in blood, genital fluids and breast milk.
The main ways HIV can be passed on to someone else are during unprotected sex, by sharing injecting equipment, and from a mother to her baby during pregnancy, birth or through breastfeeding. But there are ways of preventing HIV infection in all of these situations."
Tuesday, July 20, 2010
OCEAN
Ocean Surface a Boon for Extreme Event Forecasts, Warnings
07.16.08
Satellites passed over the Indian Ocean tsunami of December 2004. Two of those satellites--Jason 1 and Topex/Poseidon--were equipped with altimeters that for the first time measured the height of a tsunami in the open ocean. Image credit: NASA/JPLLarger viewFor humans in the path of destructive hurricanes and tsunamis, an accurate warning of the pending event is critical for damage control and survival. Such warnings, however, require a solid base of scientific observations, and a new satellite is ready for the job.
The Ocean Surface Topography Mission (OSTM)/Jason 2 adds to the number of eyes in the sky measuring sea surface and wave heights across Earth's oceans. The increased coverage will help researchers improve current models for practical use in predicting hurricane intensity, while providing valuable data that can be used to improve tsunami warning models.
"When it comes to predicting hurricane intensity, the curve in the last 40 years has been somewhat flat, with little advance in how to reduce error in predicted intensity," said Gustavo Goni, of the National Oceanic and Atmospheric Administration (NOAA) in Miami. Maps of sea surface height created from satellites, however, could help change the curve.
Satellites that measure sea surface height have been running operationally nonstop since November 1992. But more than one is needed to fly at the same time in order to identify all the features that could be responsible for intensification of tropical cyclones all over Earth. The OSTM/Jason 2 mission will help make the additional coverage possible.
NASA, university and NOAA investigators, including Goni, work to transform sea surface height information obtained from satellites, such as OSTM/Jason 2, into maps of ocean heat content. Forecasters can use the maps to develop models to predict how hurricanes will strengthen.
Determining heat content from sea surface height is possible because warm water is less dense and hence sits higher than cooler water. In some regions, such as inside and outside the Gulf Stream current, the temperature differences result in more than a one-meter (three-foot) difference in sea surface height. Goni and colleagues use this established concept to estimate from sea level variations how much heat is stored in the upper ocean in areas where hurricanes typically develop and intensify.
While sea surface height may not necessarily be the most significant parameter for hurricane intensity forecasts, researchers now know that if sea surface height is accounted for in current forecast models, errors in forecasts for the most intense storms are reduced. For weak storms, the reduction in error is not very significant. However, for storms in the strongest category 5 range, the heat content in the upper ocean derived from sea surface height becomes increasingly important. "This is a good thing, because these are the storms that produce the most damage," Goni said.
"OSTM/Jason 2 will help us to keep the necessary coverage that we need to identify ocean features that can be linked to tropical cyclone intensification, because with only one satellite we may miss some of them," Goni said.
Upper ocean heat content derived from sea surface height is now used in operational and experimental forecast models in all seven ocean basins where tropical cyclones exist.
In December 2004, two satellites happened to be in the right place at the right time, capturing the first space-based look at a major tsunami in the open ocean. Within two hours of a magnitude 9 earthquake in the Indian Ocean southwest of Sumatra, the Jason 1 and Topex/Poseidon satellites fortuitously passed over the path of the resulting tsunami as it traveled across the ocean. It measured the leading wave, traveling hundreds of miles per hour in the open ocean, at about 0.5 meters (1.6 feet) tall.
Wave height measurements like those of the Indian Ocean tsunami do not provide an early warning because the information is not relayed to ground stations in real time. That's the job of early warning systems operated by NOAA and other global organizations that currently employ a network of open-ocean buoys and coastal tide gauges. Sea surface height measurements of tsunamis can, however, help scientists test and improve ground-based models used for early warning. One such system developed at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., and undergoing tests at NOAA's Pacific Tsunami Warning Center, Ewa Beach, Hawaii, could become operational within about three years.
Most tsunamis are caused by undersea earthquakes. Using the JPL-developed system, when seismometers first identify and locate a large earthquake, scientists can use GPS measurements to search around the earthquake's source to see if land has shifted, potentially spurring a tsunami. Scientists can then immediately compile the earthquake's size, location, and land movement into a computer program that generates a model tsunami to determine the risk of a dangerous wave. After the wave passes, scientists can search through wave height data from satellites and verify what the model predicted.
"Satellite data play the crucial role of verifying tsunami models by testing real tsunami events," said JPL research scientist Tony Song. "If an earthquake generates a tsunami, does the satellite data match observations on the ground and model predictions?"
"One of the unique pieces of satellite observations is the large-scale perspective," said JPL research scientist Philip Callahan. Tsunamis can have waves more than 161 kilometers (100 miles) long. Such a wave would likely go unnoticed by an observer in a boat on the ocean's surface. But satellite altimeters like OSTM/Jason 2 can see this very long wave and measure its height to an accuracy of about 2.5 centimeters (one inch).
Scientists' ability to test tsunami warning models will be aided by OSTM/Jason 2. With the Topex/Poseidon mission now ended, the currently orbiting Jason 1 has now been joined by and will eventually be replaced by OSTM/Jason 2. This will help ensure that future tsunamis will also be observed by satellites as well as by buoys and tide gauges.
"The biggest value in satellite measurements of sea surface height is not in direct warning capability, but in improving models so when an earthquake is detected, you can make reliable predictions and reduce damage to property and people," Callahan said.
OCEAN
Ocean Surface a Boon for Extreme Event Forecasts, Warnings
07.16.08
Satellites passed over the Indian Ocean tsunami of December 2004. Two of those satellites--Jason 1 and Topex/Poseidon--were equipped with altimeters that for the first time measured the height of a tsunami in the open ocean. Image credit: NASA/JPLLarger viewFor humans in the path of destructive hurricanes and tsunamis, an accurate warning of the pending event is critical for damage control and survival. Such warnings, however, require a solid base of scientific observations, and a new satellite is ready for the job.
The Ocean Surface Topography Mission (OSTM)/Jason 2 adds to the number of eyes in the sky measuring sea surface and wave heights across Earth's oceans. The increased coverage will help researchers improve current models for practical use in predicting hurricane intensity, while providing valuable data that can be used to improve tsunami warning models.
"When it comes to predicting hurricane intensity, the curve in the last 40 years has been somewhat flat, with little advance in how to reduce error in predicted intensity," said Gustavo Goni, of the National Oceanic and Atmospheric Administration (NOAA) in Miami. Maps of sea surface height created from satellites, however, could help change the curve.
Satellites that measure sea surface height have been running operationally nonstop since November 1992. But more than one is needed to fly at the same time in order to identify all the features that could be responsible for intensification of tropical cyclones all over Earth. The OSTM/Jason 2 mission will help make the additional coverage possible.
NASA, university and NOAA investigators, including Goni, work to transform sea surface height information obtained from satellites, such as OSTM/Jason 2, into maps of ocean heat content. Forecasters can use the maps to develop models to predict how hurricanes will strengthen.
Determining heat content from sea surface height is possible because warm water is less dense and hence sits higher than cooler water. In some regions, such as inside and outside the Gulf Stream current, the temperature differences result in more than a one-meter (three-foot) difference in sea surface height. Goni and colleagues use this established concept to estimate from sea level variations how much heat is stored in the upper ocean in areas where hurricanes typically develop and intensify.
While sea surface height may not necessarily be the most significant parameter for hurricane intensity forecasts, researchers now know that if sea surface height is accounted for in current forecast models, errors in forecasts for the most intense storms are reduced. For weak storms, the reduction in error is not very significant. However, for storms in the strongest category 5 range, the heat content in the upper ocean derived from sea surface height becomes increasingly important. "This is a good thing, because these are the storms that produce the most damage," Goni said.
"OSTM/Jason 2 will help us to keep the necessary coverage that we need to identify ocean features that can be linked to tropical cyclone intensification, because with only one satellite we may miss some of them," Goni said.
Upper ocean heat content derived from sea surface height is now used in operational and experimental forecast models in all seven ocean basins where tropical cyclones exist.
In December 2004, two satellites happened to be in the right place at the right time, capturing the first space-based look at a major tsunami in the open ocean. Within two hours of a magnitude 9 earthquake in the Indian Ocean southwest of Sumatra, the Jason 1 and Topex/Poseidon satellites fortuitously passed over the path of the resulting tsunami as it traveled across the ocean. It measured the leading wave, traveling hundreds of miles per hour in the open ocean, at about 0.5 meters (1.6 feet) tall.
Wave height measurements like those of the Indian Ocean tsunami do not provide an early warning because the information is not relayed to ground stations in real time. That's the job of early warning systems operated by NOAA and other global organizations that currently employ a network of open-ocean buoys and coastal tide gauges. Sea surface height measurements of tsunamis can, however, help scientists test and improve ground-based models used for early warning. One such system developed at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., and undergoing tests at NOAA's Pacific Tsunami Warning Center, Ewa Beach, Hawaii, could become operational within about three years.
Most tsunamis are caused by undersea earthquakes. Using the JPL-developed system, when seismometers first identify and locate a large earthquake, scientists can use GPS measurements to search around the earthquake's source to see if land has shifted, potentially spurring a tsunami. Scientists can then immediately compile the earthquake's size, location, and land movement into a computer program that generates a model tsunami to determine the risk of a dangerous wave. After the wave passes, scientists can search through wave height data from satellites and verify what the model predicted.
"Satellite data play the crucial role of verifying tsunami models by testing real tsunami events," said JPL research scientist Tony Song. "If an earthquake generates a tsunami, does the satellite data match observations on the ground and model predictions?"
"One of the unique pieces of satellite observations is the large-scale perspective," said JPL research scientist Philip Callahan. Tsunamis can have waves more than 161 kilometers (100 miles) long. Such a wave would likely go unnoticed by an observer in a boat on the ocean's surface. But satellite altimeters like OSTM/Jason 2 can see this very long wave and measure its height to an accuracy of about 2.5 centimeters (one inch).
Scientists' ability to test tsunami warning models will be aided by OSTM/Jason 2. With the Topex/Poseidon mission now ended, the currently orbiting Jason 1 has now been joined by and will eventually be replaced by OSTM/Jason 2. This will help ensure that future tsunamis will also be observed by satellites as well as by buoys and tide gauges.
"The biggest value in satellite measurements of sea surface height is not in direct warning capability, but in improving models so when an earthquake is detected, you can make reliable predictions and reduce damage to property and people," Callahan said.
SOLAR SYSTEM
Did You Know...
07.25.08
Artist's impression of our solar system's boundaries. Credit: NASA GSFC.> View large image
> Watch video about the solar system's boundariesWhat defines the boundary of the solar system?
What do we mean when we say something has an edge, or a boundary? Some things, like a table or a soccer field have clear edges and boundaries. Other objects, like cities and towns, have boundaries that aren’t as easy to see. It is hard to say where they end and something else begins. The solar system is more like a city than a table or soccer field.
You could say that the solar system extends as far as the influence of the Sun. That could mean the influence of the Sun’s light, or the influence of the Sun’s gravity, or the influence of the Sun's magnetic field and solar wind.
Could the reach of the Sun’s light be a good way to decide how far the solar system extends? The light from the Sun gets fainter as you move farther away, but there is no boundary where the light stops or where it suddenly gets weaker. How about gravity? Just like light, the influence of the Sun’s gravity extends without limit, although it gets weaker farther away from the Sun. There is not a boundary at which it stops. Astronomers are still discovering objects in the outer solar system beyond Pluto.
The solar wind is different from light or gravity. As it streams away from the Sun it races out toward the space between the stars. We think of this space as “empty” but it contains traces of gas and dust. The solar wind blows against this material and clears out a bubble-like region in this gas. This bubble that surrounds the Sun and the solar system is called the heliosphere. This is not a bubble like a soap bubble, but more like a cloud of foggy breath that you breathe into chilly winter air. Scientists believe that the closest parts of the heliosphere are 90 times farther away than the distance between the Earth and Sun. That’s three times as far as Pluto.
The heliosphere defines one type of boundary of the solar system.
Illustration of the solar system's boundaries. Credit: NASA GSFC. > View large image
Even though the interstellar medium has a low density, it still has a pressure (similar to air pressure). The solar wind also has a pressure. Close to the Sun, the solar wind has a large pressure and can easily push the interstellar medium away from the Sun. Further away from the Sun, the pressure from the interstellar medium is strong enough to slow down and eventually stop the flow of solar wind from traveling into its surroundings. The entire area or bubble inside the boundary of the solar system is called the heliosphere. The place where the solar wind slows down and begins to interact with the interstellar medium is called the heliosheath. The heliosheath has a few parts: the termination shock (the innermost part of the boundary), the heliopause (the outermost part of the boundary) and the part in between the inner and outer boundary.
Since the Sun is moving relative to the interstellar medium around it, the heliosphere forms a wave or shock in the interstellar medium like a boat in the ocean. This is called the bow shock or wave.
What is the interstellar medium?
Outer space is not empty space. The interstellar medium (ISM) is the name for the stuff that is in space between stars in our Milky Way Galaxy. The ISM is mostly made of clouds of hydrogen and helium. The rest of the ISM mostly consists of heavier elements like carbon. About one percent of the ISM is in the form of dust.
In some places in space the ISM is not dense at all, but it is much more dense in other regions. However, even the densest parts of the ISM are 1014 (100,000,000,000,000 or 100 trillion) times less dense than the Earth's atmosphere. The density of the ISM ranges from 0.003 molecules per cubic centimeter in regions of hot ionized gases, or plasma, to more than 100,000 molecules per cubic centimeter in regions where stars form. On average, there are only 1,000 grains of dust in each cubic kilometer of space!
> Click here for more information on the composition of the ISM.
Stars form in regions of the ISM that are dense enough for gravity to pull the gas and dust together to make compact, hot spheres. These protostars eventually become so dense and hot that nuclear fusion begins, and they become stars.
Although they are not alive, stars have life-cycles. They are born from the ISM, grow, and die. Some stars die in an explosion called a supernova. After it explodes, a supernova's material is recycled into the ISM.
Exploding stars continually replenish the ISM with their material. In turn, gravity pulls the ISM material together to form more stars.
What is the bow shock or bow wave?
A bow shock or wave will form in front of the heliosphere, as the Sun moves through the interstellar medium. A bow wave is similar to what happens at the prow of a boat, while a bow shock is similar to the shockwave that forms in front of a supersonic jet.
If the Sun is moving faster than the speed of sound in the interstellar medium, a bow shock will form. Otherwise, if the Sun is not traveling that fast a bow wave will form.
What is the heliopause?
The heliopause is the boundary between the Sun's solar wind and the interstellar medium. The solar wind blows a "bubble" known as the heliosphere into the interstellar medium. The outer border of this "bubble" is where the solar wind's strength is no longer great enough to push back the interstellar medium. This is known as the heliopause, and is often considered to be the outer border of the solar system. The zone between the termination shock and the heliopause is known as the heliosheath.
What is the termination shock?
The termination shock is the boundary marking one of the outer limits of the Sun's influence, and is one boundary of the solar system. It is where the bubble of solar wind particles slows down so that the particles are traveling slower than the speed of sound. The solar wind particles slow down when they begin to press into the interstellar medium. The solar wind is made of plasma, and when it slows in this way, it goes through many changes. The solar wind plasma gets smooshed together, or compressed like people crowded together in a tiny room. When it is compressed, it also becomes much hotter, in the same way as a bicycle pump heats up in your hand when you vigorously inflate a tire. Also, the solar wind carries outward some of the Sun's magnetic field, which now gets stronger at the termination shock and twists around. We have only two direct measurements of the distance to the Termination Shock. These measurements were made by Voyager 1 and Voyager 2. Voyager 1 crossed the termination shock at 94 astronomical units (AU) and Voyager 2 crossed at 84 AU.
> Learn more about the Voyager mission
Even though the Interstellar Medium has a low density, it still has a pressure (think of air pressure.) The solar wind flow also represents a strong outward pressure. Close to the Sun, the solar wind has a high pressure and can easily push the interstellar medium away from the Sun. Further away from the Sun, the pressure from the Interstellar Medium is strong enough to slow down and eventually stop the flow solar wind from traveling into space. The place where the speed of the solar wind becomes slower than the speed of sound is called the termination shock.
A similar shock is formed when you run water from a faucet into a sink. When the stream of water hits the sink basin, the flowing water spreads out at a relatively fast speed, forming a disk of shallow water that quickly moves outward, like the solar wind inside the termination shock. Around the edge of the disk, a shock front or wall of water forms; outside the shock front, the water moves relatively slower, like outside the termination shock. Remember, the water shock is only 2-dimensional or flat. The Boundary of our solar system is 3-dimensional like a sphere.
Artist's impression of IBEX exploring the edge of our Solar System. Credit: NASA GSFC.> View large image
> Watch videoHow does the solar system boundary affect me?
This graph depicts the fraction of high energy cosmic rays (greater than 100 MeV) that pass through the boundary of the solar system. 100% of them are present outside of the Bow Shock. There is a small drop off in the number that make it through to the heliopause. More than 50% are stopped between the heliopause and termination shock, which is at approximately 100 AU. This leaves a fraction less than 25% to permeate to the inner solar system.
The solar system boundary may be defined as the region where the solar wind slows down and interacts with the Interstellar Medium.
If the solar system did not have a boundary, or if the boundary changed size so that it was inside the orbit of the Earth, then there would be at least 4 times the amount of cosmic rays in the solar system. Luckily the Earth's magnetosphere protects us from some of the cosmic rays that come from outside our solar system. However, if there were a dramatic increase in the number of cosmic rays entering the solar system, it could change the amount of high energy cosmic rays that would be able to reach Earth's surface. Damage to the Earth's ozone layer could occur and cosmic rays may cause damage and mutation to DNA.
What are cosmic rays?
'Cosmic ray' is the (confusing) name given to any kind of energetic particle that comes from outside the Earth. These particles could be single protons, nuclei of different atoms or electrons. Cosmic rays are neither light nor beams of particles, so maybe they should be renamed energetic cosmic particles. Cosmic rays are often made when a star explodes. This is called a supernova. Some cosmic rays can be produced by the Sun and some can even come from as far away as other galaxies. These particles are very energetic, but also very small. They rarely directly hit anything as they travel through space, but if they do it can cause nuclear reactions with atoms. These reactions are similar to the activities in particle accelerators. The Sun's heliosphere protects the planets and other objects in the solar system from some of these dangerous particles. The Earth's magnetosphere and atmosphere protect life on Earth from cosmic rays that make it through the heliosphere. Studying the heliosphere will help us to prepare adequate shielding during future space travel
How do cosmic rays affect DNA?
Cosmic rays can seriously damage DNA. If DNA damage cannot be repaired by the cell, the cell could die. If the damage is copied into more cells, then a mutation could occur. Exposure to large amounts of cosmic rays could increase the risks for cancer, cataracts and neurological disorders. Long term exposure to cosmic rays, or short intense bursts, could affect the evolution of life on Earth.
What are energetic neutral atoms?
Energetic Neutral Atoms (ENAs) are particles with no charge that move relatively fast. ENAs are formed from particles that are ionized, meaning they have lost electrons. Sometimes, these ions interact with neutral atoms taking the electrons from those neutral atoms and becoming neutral themselves. Since the particle is no longer charged (it has equal numbers of protons and electrons) it no longer reacts to the magnetic fields, and travels in a straight line from the spot where the interaction occurred.
This interaction is called charge exchange. Charge exchange can happen between solar wind ions and neutral atoms from the Interstellar Medium. Some of these ENAs happen to travel in just the right way so that they enter the IBEX spacecraft for collection. There are so many energetic particles that interact with interstellar neutrals, that even though they could travel in any direction, the IBEX sensors are able to pick up between 1 per hour and a few per minute.
SOLAR SYSTEM
Did You Know...
07.25.08
Artist's impression of our solar system's boundaries. Credit: NASA GSFC.> View large image
> Watch video about the solar system's boundariesWhat defines the boundary of the solar system?
What do we mean when we say something has an edge, or a boundary? Some things, like a table or a soccer field have clear edges and boundaries. Other objects, like cities and towns, have boundaries that aren’t as easy to see. It is hard to say where they end and something else begins. The solar system is more like a city than a table or soccer field.
You could say that the solar system extends as far as the influence of the Sun. That could mean the influence of the Sun’s light, or the influence of the Sun’s gravity, or the influence of the Sun's magnetic field and solar wind.
Could the reach of the Sun’s light be a good way to decide how far the solar system extends? The light from the Sun gets fainter as you move farther away, but there is no boundary where the light stops or where it suddenly gets weaker. How about gravity? Just like light, the influence of the Sun’s gravity extends without limit, although it gets weaker farther away from the Sun. There is not a boundary at which it stops. Astronomers are still discovering objects in the outer solar system beyond Pluto.
The solar wind is different from light or gravity. As it streams away from the Sun it races out toward the space between the stars. We think of this space as “empty” but it contains traces of gas and dust. The solar wind blows against this material and clears out a bubble-like region in this gas. This bubble that surrounds the Sun and the solar system is called the heliosphere. This is not a bubble like a soap bubble, but more like a cloud of foggy breath that you breathe into chilly winter air. Scientists believe that the closest parts of the heliosphere are 90 times farther away than the distance between the Earth and Sun. That’s three times as far as Pluto.
The heliosphere defines one type of boundary of the solar system.
Illustration of the solar system's boundaries. Credit: NASA GSFC. > View large image
Even though the interstellar medium has a low density, it still has a pressure (similar to air pressure). The solar wind also has a pressure. Close to the Sun, the solar wind has a large pressure and can easily push the interstellar medium away from the Sun. Further away from the Sun, the pressure from the interstellar medium is strong enough to slow down and eventually stop the flow of solar wind from traveling into its surroundings. The entire area or bubble inside the boundary of the solar system is called the heliosphere. The place where the solar wind slows down and begins to interact with the interstellar medium is called the heliosheath. The heliosheath has a few parts: the termination shock (the innermost part of the boundary), the heliopause (the outermost part of the boundary) and the part in between the inner and outer boundary.
Since the Sun is moving relative to the interstellar medium around it, the heliosphere forms a wave or shock in the interstellar medium like a boat in the ocean. This is called the bow shock or wave.
What is the interstellar medium?
Outer space is not empty space. The interstellar medium (ISM) is the name for the stuff that is in space between stars in our Milky Way Galaxy. The ISM is mostly made of clouds of hydrogen and helium. The rest of the ISM mostly consists of heavier elements like carbon. About one percent of the ISM is in the form of dust.
In some places in space the ISM is not dense at all, but it is much more dense in other regions. However, even the densest parts of the ISM are 1014 (100,000,000,000,000 or 100 trillion) times less dense than the Earth's atmosphere. The density of the ISM ranges from 0.003 molecules per cubic centimeter in regions of hot ionized gases, or plasma, to more than 100,000 molecules per cubic centimeter in regions where stars form. On average, there are only 1,000 grains of dust in each cubic kilometer of space!
> Click here for more information on the composition of the ISM.
Stars form in regions of the ISM that are dense enough for gravity to pull the gas and dust together to make compact, hot spheres. These protostars eventually become so dense and hot that nuclear fusion begins, and they become stars.
Although they are not alive, stars have life-cycles. They are born from the ISM, grow, and die. Some stars die in an explosion called a supernova. After it explodes, a supernova's material is recycled into the ISM.
Exploding stars continually replenish the ISM with their material. In turn, gravity pulls the ISM material together to form more stars.
What is the bow shock or bow wave?
A bow shock or wave will form in front of the heliosphere, as the Sun moves through the interstellar medium. A bow wave is similar to what happens at the prow of a boat, while a bow shock is similar to the shockwave that forms in front of a supersonic jet.
If the Sun is moving faster than the speed of sound in the interstellar medium, a bow shock will form. Otherwise, if the Sun is not traveling that fast a bow wave will form.
What is the heliopause?
The heliopause is the boundary between the Sun's solar wind and the interstellar medium. The solar wind blows a "bubble" known as the heliosphere into the interstellar medium. The outer border of this "bubble" is where the solar wind's strength is no longer great enough to push back the interstellar medium. This is known as the heliopause, and is often considered to be the outer border of the solar system. The zone between the termination shock and the heliopause is known as the heliosheath.
What is the termination shock?
The termination shock is the boundary marking one of the outer limits of the Sun's influence, and is one boundary of the solar system. It is where the bubble of solar wind particles slows down so that the particles are traveling slower than the speed of sound. The solar wind particles slow down when they begin to press into the interstellar medium. The solar wind is made of plasma, and when it slows in this way, it goes through many changes. The solar wind plasma gets smooshed together, or compressed like people crowded together in a tiny room. When it is compressed, it also becomes much hotter, in the same way as a bicycle pump heats up in your hand when you vigorously inflate a tire. Also, the solar wind carries outward some of the Sun's magnetic field, which now gets stronger at the termination shock and twists around. We have only two direct measurements of the distance to the Termination Shock. These measurements were made by Voyager 1 and Voyager 2. Voyager 1 crossed the termination shock at 94 astronomical units (AU) and Voyager 2 crossed at 84 AU.
> Learn more about the Voyager mission
Even though the Interstellar Medium has a low density, it still has a pressure (think of air pressure.) The solar wind flow also represents a strong outward pressure. Close to the Sun, the solar wind has a high pressure and can easily push the interstellar medium away from the Sun. Further away from the Sun, the pressure from the Interstellar Medium is strong enough to slow down and eventually stop the flow solar wind from traveling into space. The place where the speed of the solar wind becomes slower than the speed of sound is called the termination shock.
A similar shock is formed when you run water from a faucet into a sink. When the stream of water hits the sink basin, the flowing water spreads out at a relatively fast speed, forming a disk of shallow water that quickly moves outward, like the solar wind inside the termination shock. Around the edge of the disk, a shock front or wall of water forms; outside the shock front, the water moves relatively slower, like outside the termination shock. Remember, the water shock is only 2-dimensional or flat. The Boundary of our solar system is 3-dimensional like a sphere.
Artist's impression of IBEX exploring the edge of our Solar System. Credit: NASA GSFC.> View large image
> Watch videoHow does the solar system boundary affect me?
This graph depicts the fraction of high energy cosmic rays (greater than 100 MeV) that pass through the boundary of the solar system. 100% of them are present outside of the Bow Shock. There is a small drop off in the number that make it through to the heliopause. More than 50% are stopped between the heliopause and termination shock, which is at approximately 100 AU. This leaves a fraction less than 25% to permeate to the inner solar system.
The solar system boundary may be defined as the region where the solar wind slows down and interacts with the Interstellar Medium.
If the solar system did not have a boundary, or if the boundary changed size so that it was inside the orbit of the Earth, then there would be at least 4 times the amount of cosmic rays in the solar system. Luckily the Earth's magnetosphere protects us from some of the cosmic rays that come from outside our solar system. However, if there were a dramatic increase in the number of cosmic rays entering the solar system, it could change the amount of high energy cosmic rays that would be able to reach Earth's surface. Damage to the Earth's ozone layer could occur and cosmic rays may cause damage and mutation to DNA.
What are cosmic rays?
'Cosmic ray' is the (confusing) name given to any kind of energetic particle that comes from outside the Earth. These particles could be single protons, nuclei of different atoms or electrons. Cosmic rays are neither light nor beams of particles, so maybe they should be renamed energetic cosmic particles. Cosmic rays are often made when a star explodes. This is called a supernova. Some cosmic rays can be produced by the Sun and some can even come from as far away as other galaxies. These particles are very energetic, but also very small. They rarely directly hit anything as they travel through space, but if they do it can cause nuclear reactions with atoms. These reactions are similar to the activities in particle accelerators. The Sun's heliosphere protects the planets and other objects in the solar system from some of these dangerous particles. The Earth's magnetosphere and atmosphere protect life on Earth from cosmic rays that make it through the heliosphere. Studying the heliosphere will help us to prepare adequate shielding during future space travel
How do cosmic rays affect DNA?
Cosmic rays can seriously damage DNA. If DNA damage cannot be repaired by the cell, the cell could die. If the damage is copied into more cells, then a mutation could occur. Exposure to large amounts of cosmic rays could increase the risks for cancer, cataracts and neurological disorders. Long term exposure to cosmic rays, or short intense bursts, could affect the evolution of life on Earth.
What are energetic neutral atoms?
Energetic Neutral Atoms (ENAs) are particles with no charge that move relatively fast. ENAs are formed from particles that are ionized, meaning they have lost electrons. Sometimes, these ions interact with neutral atoms taking the electrons from those neutral atoms and becoming neutral themselves. Since the particle is no longer charged (it has equal numbers of protons and electrons) it no longer reacts to the magnetic fields, and travels in a straight line from the spot where the interaction occurred.
This interaction is called charge exchange. Charge exchange can happen between solar wind ions and neutral atoms from the Interstellar Medium. Some of these ENAs happen to travel in just the right way so that they enter the IBEX spacecraft for collection. There are so many energetic particles that interact with interstellar neutrals, that even though they could travel in any direction, the IBEX sensors are able to pick up between 1 per hour and a few per minute.
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