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| Never trust anyone who wants what you've got. |
Never trust anyone who wants what you've got.
Showing posts with label Earth. Show all posts
Showing posts with label Earth. Show all posts
Thursday, June 19, 2014
Trust and Nature
Never trust anyone who wants what you've got.
Unconditional
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| Unconditional love really exists in each of us, in nature. It is part of our deep inner human being. |
Tuesday, June 10, 2014
Mercury and Its Effects
Mercury pollution can be a serious health threat, especially for children and pregnant women.
Mercury is emitted to the air by power plants, cement plants, certain chemical manufacturers and other industrial facilities. In addition, over the years, many companies have used mercury to manufacture a range of products including thermometers, thermostats and automotive light switches. These products can release mercury, particularly at the end of their useful life during waste handling and disposal. Mercury pollution released into the environment becomes a serious threat when it settles into oceans and waterways, where it builds up in fish that we eat. Children and women of childbearing age are most at risk.
Mercury in Fish
Once mercury enters a waterway, naturally occurring bacteria absorb it and convert it to a form called methyl mercury.
This transition is particularly significant for humans, who absorb methyl mercury easily and are especially vulnerable to its effects.
Mercury then works its way up the food chain as large fish consume contaminated smaller fish. Instead of dissolving or breaking down, mercury accumulates at ever-increasing levels. Predatory fish such as large tuna, swordfish, shark and mackerel can have mercury concentrations in their bodies that are 10,000 times higher than those of their surrounding habitat.
Mercury and Human Health
Humans risk ingesting dangerous levels of mercury when they eat contaminated fish. Since mercury is odorless, invisible and accumulates in the meat of the fish, it is not easy to detect and can't be avoided by trimming off the skin or other parts.
Once in the human body, mercury acts as a neurotoxin, interfering with the brain and nervous system.
Exposure to mercury can be particularly hazardous for pregnant women and small children. During the first several years of life, a child's brain is still developing and rapidly absorbing nutrients. Even in low doses, mercury may affect a child's development, delaying walking and talking, shortening attention span and causing learning disabilities. Less frequent, high dose prenatal and infant exposures to mercury can cause mental retardation, cerebral palsy, deafness and blindness.
In adults, mercury poisoning can adversely affect fertility and blood pressure regulation and can cause memory loss, tremors, vision loss and numbness of the fingers and toes. A growing body of evidence suggests that exposure to mercury may also lead to heart disease.
Mercury and a High-Fish Diet
A 2009 study of federal Centers for Disease Control and Prevention (CDC) data concluded that roughly one in 40 women of childbearing age have mercury in their blood above 5.8 micrograms per liter of blood - a level that could pose a risk to a developing fetus. This is a significant improvement from data ten years ago, which showed that one out of 15 women had mercury in their blood at this level. Newer science indicates, however, that mercury actually concentrates in the umbilical cord blood that goes to the fetus, so mercury levels as low as 3.4 micrograms per liter of a mother’s blood are now a concern. Nearly one in 13 women of reproductive age in the United States has mercury in her blood at or above this level, according to the latest data.
Dr. Jane Hightower, a doctor of internal medicine at the California Pacific Medical Center in San Francisco also linked fish consumption to elevated mercury levels when she tested her own patients. Her 2003 study found that 89 percent of the participating patients - chosen because of their fish-heavy diets - had elevated mercury levels. Many had levels as much as four times that which the Environmental Protection Agency considers safe.
The good news is that Dr. Hightower and other health professionals conclude that high mercury levels are reversible: cutting consumption of mercury-contaminated fish causes blood mercury to drop, though it can take six months or more.
Poisoned by Mercury
Mercury is a chemical element with the symbol Hg and atomic number 80.
Mercury is a naturally occurring element that is found in air, water and soil. A highly toxic form (methyl-mercury) builds up in fish, shellfish and animals that eat fish. Fish and shellfish are the main sources of methyl-mercury exposure to humans.
Mercury exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system. High levels of methyl-mercury in the bloodstream of unborn babies and young children may harm the developing nervous system, making the child less able to think and learn.
Symptoms of methyl-mercury poisoning may include impairment of peripheral vision; disturbances in sensations ("pins and needles" feelings); lack of coordination; impairment of speech, hearing, walking; and muscle weakness.
Elemental (metallic) mercury primarily causes health effects when it is breathed as a vapor where it can be absorbed through the lungs. Symptoms include tremors, emotional changes, insomnia, weakness, muscle atrophy, twitching, headaches, disturbances in sensations, changes in nerve responses, and performance deficits on tests of cognitive function. Higher exposures may result in kidney effects, respiratory failure and death.
Consult your doctor if you believe you have been exposed to mercury.
Recycling of mercury-containing products is one of the best ways to help prevent mercury releases to the environment by keeping these products out of landfills and incinerators.
Mercury poisoning facts by John P. Cunha, DO, FACOEP
Tuesday, May 13, 2014
Aquatic Biodiversity
Marine, coastal and inland areas support a rich assortment of aquatic biological diversity that contributes to the economic, cultural, nutritional, social, recreational and spiritual betterment of human populations. Life originated in the world’s oceans and over the millennia has spread inland and evolved into the diverse forms used today by a variety of stakeholders, including commercial and artisan fishers, fish farmers, developers and tourists.
Maintaining aquatic biodiversity in capture fisheries is fundamental to guaranteeing the productivity of the world’s fish stocks, their resilience and their adaptability to environmental change, including climate change. The world’s capture fisheries harvested an estimated 1 938 aquatic species or species groups in 2011. The majority of this diversity was fin fishes (1 402 species), followed by crustaceans (194 species), mollusks (150 species) and other species. As such, capture fisheries use a greater variety of biological diversity than any other food production sector.
Genetic biodiversity in aquaculture provides the raw ingredients that allow breeders to improve the production, efficiency and marketability of species of aquatic plants and animals. Over 360 species of fish, invertebrates and plants are farmed around the world. This represents a wealth of genetic diversity both within and among species that helps make aquaculture one of the fastest growing food production sectors. Humans began to domesticate terrestrial plants and animals about 12 000 years ago, however more than 90 percent of all cultured aquatic species have only been domesticated since the beginning of the twentieth century.
Although aquatic biodiversity plays a vital role in livelihoods, it is being threatened by factors within the fisheries sector, such as overfishing, destructive fishing practices and introduction of alien species, as well as by external factors such as habitat loss and degradation mainly caused by land-based activities. It will be essential to reduce these threats to continue providing high quality nutrients and economic opportunities to the millions of people that depend on aquatic biodiversity.
The FAO Fisheries and Aquaculture Department is responsible for maintaining information on capture fisheries and aquaculture production, and the development of knowledge, policy and intergovernmental instruments devoted to the promotion of sustainable fisheries and aquaculture practices. In 2007, the FAO Fisheries and Aquaculture Department published the Technical Guidelines on Genetic Resource Management. These Technical Guidelines were developed to support sections of the FAO’s Code of Conduct for Responsible Fisheries on aspects of genetic resource management in aquaculture. The effective management of aquatic biodiversity can help promote responsible aquaculture by increasing production output and efficiency and help minimize adverse impacts on the environment.Forests Biodiversity
Forests are among the most important repositories of terrestrial biological diversity. Together, tropical, temperate and boreal forests offer very diverse habitats for plants, animals and micro-organisms.
Biological diversity is the basis for a wide array of goods and services provided by forests. The variety of forest trees and shrubs play a vital role in the daily life of rural communities in many areas, as sources of wood and non-wood products, as contributors to soil and water conservation, and as repositories of aesthetic, ethical, cultural and religious values. Forest animals are a vital source of nutrition and income to many people, and have vital roles in forest ecology, such as pollination, seed predation, dispersal and germination, and predation on potential pest species.
Forest biological diversity is one of the seven thematic elements of the concept of Sustainable Forest Management approved by the General Assembly of the UN in 2007, together with the Non-Legally Binding Instrument on All Types of Forests.
Forests provide more than 10% of the GDP in many of the poorest countries. It is estimated that the forestry sector provides formal employment for 10 million people and informal employment for additional 30 to 50 million people in developing countries. Notwithstanding such a relevant role in world economy, progress towards sustainable forest management is still limited, and there is continuing loss and degradation of forests in many developing countries. Losing forest diversity means missing opportunities for medicines, food, raw materials and employment opportunities, in one word: welfare.
Biological diversity is the basis for a wide array of goods and services provided by forests. The variety of forest trees and shrubs play a vital role in the daily life of rural communities in many areas, as sources of wood and non-wood products, as contributors to soil and water conservation, and as repositories of aesthetic, ethical, cultural and religious values. Forest animals are a vital source of nutrition and income to many people, and have vital roles in forest ecology, such as pollination, seed predation, dispersal and germination, and predation on potential pest species.
Forest biological diversity is one of the seven thematic elements of the concept of Sustainable Forest Management approved by the General Assembly of the UN in 2007, together with the Non-Legally Binding Instrument on All Types of Forests.
Forests provide more than 10% of the GDP in many of the poorest countries. It is estimated that the forestry sector provides formal employment for 10 million people and informal employment for additional 30 to 50 million people in developing countries. Notwithstanding such a relevant role in world economy, progress towards sustainable forest management is still limited, and there is continuing loss and degradation of forests in many developing countries. Losing forest diversity means missing opportunities for medicines, food, raw materials and employment opportunities, in one word: welfare.
The FAO Forestry Programme focuses on how to maximize the potential of forests, trees and related resources to improve people’s economic, social and environmental conditions while ensuring that the resource is conserved to meet the needs of future generations.
FAO works to improve the knowledge on sustainable forest and wildlife management, and supports the development and implementation of appropriate policies and practices to ensure forest and wildlife protection in order to maintain or improve their capacity to produce wood and non-wood products, sustain wildlife populations, conserve biodiversity, safeguard wildlife habitat, mitigate climate change, and protect soils and watersheds.
Plants Biodiversity
About 7,000 species of plants have been cultivated for consumption in human history. The great diversity of varieties resulting from human and ecosystem interaction guaranteed food for the survival and development of human populations throughout the world in spite of pests, diseases, climate fluctuations, droughts and other unexpected environmental events.
Presently, only about 30 crops provide 95% of human food energy needs, four of which (rice, wheat, maize and potato) are responsible for more than 60% of our energy intake. Due to the dependency on this relatively small number of crops for global food security, it will be crucial to maintain a high genetic diversity within these crops to deal with increasing environmental stress and to provide farmers and researchers with opportunities to breed for crops that can be cultivated under unfavorable conditions, such as drought, salinity, flooding, poor soils and extreme temperatures.
Plant genetic resources are the basis of food security and consist of diversity of seeds and planting material of traditional varieties and modern cultivars, crop wild relatives and other wild plant species. These resources are used as food, feed for domesticated animals, fibber, clothing, shelter and energy. The conservation and sustainable use of PGRFA is necessary to ensure crop production and meet growing environmental challenges and climate change. The loss of these resources or a lack of adequate linkages between conservation and their use poses a severe threat to the world’s food security in the long term. The potential of plant genetic resources for food security, sustainable livelihoods, adequate nutrition and adaptation to climate change is enormous, if managed in a sustainable manner.
Presently, only about 30 crops provide 95% of human food energy needs, four of which (rice, wheat, maize and potato) are responsible for more than 60% of our energy intake. Due to the dependency on this relatively small number of crops for global food security, it will be crucial to maintain a high genetic diversity within these crops to deal with increasing environmental stress and to provide farmers and researchers with opportunities to breed for crops that can be cultivated under unfavorable conditions, such as drought, salinity, flooding, poor soils and extreme temperatures.
Plant genetic resources are the basis of food security and consist of diversity of seeds and planting material of traditional varieties and modern cultivars, crop wild relatives and other wild plant species. These resources are used as food, feed for domesticated animals, fibber, clothing, shelter and energy. The conservation and sustainable use of PGRFA is necessary to ensure crop production and meet growing environmental challenges and climate change. The loss of these resources or a lack of adequate linkages between conservation and their use poses a severe threat to the world’s food security in the long term. The potential of plant genetic resources for food security, sustainable livelihoods, adequate nutrition and adaptation to climate change is enormous, if managed in a sustainable manner.
FAO is dedicated to improve knowledge and conservation of plant genetic resources to ensure the sustainable provision of food in the long term, and contributing to make full use of the genetic resources available, including wild relatives of main crops currently used.
The most obvious reason for maintaining plant diversity is because we rely on plants for food, and a blight that targets a major crop could have serious implications. Unfortunately, the world's major staple crops have been greatly homogenized over the years, and that's not a good thing. Many countries have lost agro-biodiversity (or the diversity of their agricultural crops), which puts the cultures and livelihoods of the poorest populations at even greater risk.
Innovative new medicines are another reason to maintain biodiversity among plants. It's a dangerous world out there and plants, being for the most part immobile, have had to evolve some particularly fiendish and unique defenses that scientists can use for medicinal purposes. Even animals, mobile creatures that they are, have had to develop some pretty potent defenses that can help scientists cook up new medicines. But in the most basic sense, the reason we need plants - along with organisms like algae and cyano-bacteria - is because they're essential for a properly functioning planet. We wouldn't even have the oxygen that we're so fond of breathing, for example, without photosynthesis.
Fortunately, conservationists had the insight to begin conserving plants in the 1950s. Some plants are maintained in their original habitats and others are held in gene banks, cell cultures and at various zoos and botanical gardens [source: FAO]. The Food and Agriculture Organization of the United Nations lists 20 major plant gene banks around the world. These banks house various types of seeds but also back up one another in the event of natural and manmade disasters.
Botanists use two methods to preserve and store a plant's genetic material. Drying and freezing seeds mimics the natural process of winter. Seeds stored by this method survive for decades. But frozen seeds must be thawed and planted to produce seeds that will grow crops. Cryonic freezing is more expensive, but it keeps stored genes "fresh" much longer than conventional drying and freezing. At cryonic temperatures, molecular action stops. Think of it as suspended animation. The frozen seed stays in the same condition, not changing or aging. The genetic seed banks around the world use these methods to store genetic and seed samples from hundreds of plants.
Monday, April 21, 2014
Researchers #CloneCells From Two Elder Men
After years of failed attempts, researchers have successfully generated stem cells from adults. The process could provide a new way for scientists to generate healthy replacements for diseased or damaged cells in patients. After years of failed attempts, researchers have finally generated stem cells from adults using the same cloning technique that produced Dolly the sheep in 1996.
A previous claim that Korean investigators had succeeded in the feat turned out to be fraudulent. Then last year, a group at Oregon Health & Science University generated stem cells using the Dolly technique, but with cells from fetuses and infants.
In this case, cells from a 35-year-old man and a 75-year-old man were used to generate two separate lines of stem cells. The process, known as nuclear transfer, involves taking the DNA from a donor and inserting it into an egg that has been stripped of its DNA. The resulting hybrid is stimulated to fuse and start dividing; after a few days the “embryo” creates a lining of stem cells that are destined to develop into all of the cells and tissues in the human body. Researchers extract these cells and grow them in the lab, where they are treated with the appropriate growth factors and other agents to develop into specific types of cells, like neurons, muscle, or insulin-producing cells.
Reporting in the journal Cell Stem Cell, Dr. Robert Lanza, chief scientific officer at biotechnology company Advanced Cell Technology, and his colleagues found that tweaking the Oregon team’s process was the key to success with reprogramming the older cells. Like the earlier team, Lanza’s group used caffeine to prevent the fused egg from dividing prematurely. Rather than leaving the egg with its newly introduced DNA for 30 minutes before activating the dividing stage, they let the eggs rest for about two hours. This gave the DNA enough time to acclimate to its new environment and interact with the egg’s development factors, which erased each of the donor cell’s existing history and reprogrammed it to act like a brand new cell in an embryo.
A previous claim that Korean investigators had succeeded in the feat turned out to be fraudulent. Then last year, a group at Oregon Health & Science University generated stem cells using the Dolly technique, but with cells from fetuses and infants.
In this case, cells from a 35-year-old man and a 75-year-old man were used to generate two separate lines of stem cells. The process, known as nuclear transfer, involves taking the DNA from a donor and inserting it into an egg that has been stripped of its DNA. The resulting hybrid is stimulated to fuse and start dividing; after a few days the “embryo” creates a lining of stem cells that are destined to develop into all of the cells and tissues in the human body. Researchers extract these cells and grow them in the lab, where they are treated with the appropriate growth factors and other agents to develop into specific types of cells, like neurons, muscle, or insulin-producing cells.
Reporting in the journal Cell Stem Cell, Dr. Robert Lanza, chief scientific officer at biotechnology company Advanced Cell Technology, and his colleagues found that tweaking the Oregon team’s process was the key to success with reprogramming the older cells. Like the earlier team, Lanza’s group used caffeine to prevent the fused egg from dividing prematurely. Rather than leaving the egg with its newly introduced DNA for 30 minutes before activating the dividing stage, they let the eggs rest for about two hours. This gave the DNA enough time to acclimate to its new environment and interact with the egg’s development factors, which erased each of the donor cell’s existing history and reprogrammed it to act like a brand new cell in an embryo.
The team, which included an international group of stem cell scientists, used 77 eggs from four different donors. They tested their new method by waiting for 30 minutes before activating 38 of the resulting embryos, and waiting two hours before triggering 39 of them. None of the 38 developed into the next stage, while two of the embryos getting extended time did. “There is a massive molecular change occurring. You are taking a fully differentiated cell, and you need to have the egg do its magic,” says Lanza. “You need to extend the reprogramming time before you can force the cell to divide.”
While a 5% efficiency may not seem laudable, Lanza says that it’s not so bad given that the stem cells appear to have had their genetic history completely erased and returned to that of a blank slate. “This procedure works well, and works with adult cells,” says Lanza.
The results also teach stem cell scientists some important lessons. First, that the nuclear transfer method that the Oregon team used is valid, and that with some changes it can be replicated using older adult cells. “It looks like the protocols we described are real, they are universal, they work in different hands, in different labs and with different cells,” says Shoukhrat Mitalopov, director of the center for embryonic cell and gene therapy at Oregon Health & Science University, and lead investigator of that study.
Second, the findings confirm that the key factor in making nuclear transfer work with human cells is not the age of the donor cell, as some experts have argued, but the quality of the donor egg. “No matter how much you tweak the protocols or optimize them, it looks like the major player in efficiency is the individual egg quality,” says Mitalipov. He notes that all of his stem cell lines came from the same egg donor. The two cell lines described by Lanza’s group also came from one egg donor.
This latest success should reignite the debate over which reprogramming method generates the most reliable, and potentially useful, stem cells for eventually treating patients. The nuclear transfer method may join two other ways of making stem cells: one, developed by James Thomson in 1998, relied on extracting them from days-old embryos left over from IVF, and another, developed by Japanese scientist Shinya Yamanaka in 2006 (and for which he was awarded the Nobel Prize), bypassed the egg and embryo completely, allowing researchers to make stem cells by modifying an adult’s cells using a mixture of just four genes.
Each method has it advantages and risks, however. IVF embryos are difficult to come by, since they require permission from couples to be used for stem cells research, and they may not be genetically matched to patients who might benefit from cells they generate.
While so-called induced pluripotent stem cells, or iPS cells, avoid the need for embryos and could be matched to patients, some studies suggest that the process may not completely reprogram cells, leaving populations of some partially reprogrammed ones in the mix. In addition, iPS cells aren’t useful for treating mitochondrial diseases, which result from mutations in the cell’s energy factories, which have their own DNA outside of the cell’s DNA in the nucleus. If a cell with a mitochondrial mutation is reprogrammed using the iPS technique, any mutations would be reprogrammed as well.
The results also teach stem cell scientists some important lessons. First, that the nuclear transfer method that the Oregon team used is valid, and that with some changes it can be replicated using older adult cells. “It looks like the protocols we described are real, they are universal, they work in different hands, in different labs and with different cells,” says Shoukhrat Mitalopov, director of the center for embryonic cell and gene therapy at Oregon Health & Science University, and lead investigator of that study.
Second, the findings confirm that the key factor in making nuclear transfer work with human cells is not the age of the donor cell, as some experts have argued, but the quality of the donor egg. “No matter how much you tweak the protocols or optimize them, it looks like the major player in efficiency is the individual egg quality,” says Mitalipov. He notes that all of his stem cell lines came from the same egg donor. The two cell lines described by Lanza’s group also came from one egg donor.
This latest success should reignite the debate over which reprogramming method generates the most reliable, and potentially useful, stem cells for eventually treating patients. The nuclear transfer method may join two other ways of making stem cells: one, developed by James Thomson in 1998, relied on extracting them from days-old embryos left over from IVF, and another, developed by Japanese scientist Shinya Yamanaka in 2006 (and for which he was awarded the Nobel Prize), bypassed the egg and embryo completely, allowing researchers to make stem cells by modifying an adult’s cells using a mixture of just four genes.
Each method has it advantages and risks, however. IVF embryos are difficult to come by, since they require permission from couples to be used for stem cells research, and they may not be genetically matched to patients who might benefit from cells they generate.
While so-called induced pluripotent stem cells, or iPS cells, avoid the need for embryos and could be matched to patients, some studies suggest that the process may not completely reprogram cells, leaving populations of some partially reprogrammed ones in the mix. In addition, iPS cells aren’t useful for treating mitochondrial diseases, which result from mutations in the cell’s energy factories, which have their own DNA outside of the cell’s DNA in the nucleus. If a cell with a mitochondrial mutation is reprogrammed using the iPS technique, any mutations would be reprogrammed as well.
Sunday, April 20, 2014
Scientists Find an #EarthTwin
An artist's concept of Kepler-186f, the first Earth-size planet found in the habitable zone, a range of distances from a star where liquid water could pool on an orbiting planet's surface. Credit NASA Ames/SETI Institute/JPL-CalTech
It is a bit bigger and somewhat colder, but a planet circling a star 500 light-years away is otherwise the closest match of our home world discovered so far, astronomers announced on Thursday.
The planet, known as Kepler 186f, named after NASA’s Kepler planet-finding mission, which detected it, has a diameter of 8,700 miles, 10 percent wider than Earth, and its orbit lies within the “Goldilocks zone” of its star, Kepler 186 — not too hot, not too cold, where temperatures could allow for liquid water to flow at the surface, making it potentially hospitable for life.
“Kepler 186f is the first validated, Earth-size planet in the habitable zone of another star,” Elisa V. Quintana of the SETI Institute and NASA’s Ames Research Center in Mountain View, Calif., said at a news conference on Thursday. “It has the right size and is at the right distance to have properties similar to our home planet.”
Dr. Quintana is the lead author of a scientific paper describing the findings in this week’s issue of the journal Science. Kepler 186f is the latest planet to be sifted out of the voluminous data collected by Kepler, which kept watch over 150,000 stars, looking for slight drops in brightness when a planet passed in front.
This follows the announcement last year that another star, Kepler 62, has two planets in its habitable zone, but those two were “super Earths,” with masses probably several times that of Earth. The gravity of those planets might be strong enough to pull in helium and hydrogen gases, making them more like mini-Neptunes than large Earths.
With its smaller size, Kepler 186f is more likely to have an Earth-like rocky surface, another step in astronomers’ quest for what might be called Earth 2.0.
“It’s a progression,” said another member of the discovery team, Thomas S. Barclay of the Bay Area Environmental Research Institute. “This planet really reminds us of Earth.”
The researchers speculate that it is made of the same stuff as Earth — iron, rock, ice, liquid water, although the relative amounts could be very different.
The gravity on Kepler 186f, too, is likely to be roughly the same as Earth’s. “You could far more easily imagine someone being able to go there and walk around on the surface,” Stephen Kane, an astronomer at San Francisco State University and another member of the research team, said in an interview.
Kepler 186f is not a perfect replica, however. It is closer to its star — a red dwarf that is smaller, cooler and fainter than our sun — than the Earth is to its; its year, the time to complete one orbit, is 130 days, not 365. It is also at the outer edge of the habitable zone, receiving less warmth, so perhaps more of its surface would freeze.
“Perhaps it’s more of an Earth cousin than an Earth twin,” Dr. Barclay said.
On the other hand, with its greater mass, Kepler 186f could conceivably have a thicker, insulating atmosphere to compensate. Red dwarfs emit more of their light at the longer infrared wavelengths, which would be more readily absorbed and trapped by ice and gases like water vapor and carbon dioxide.
“This makes the planet more efficient at absorbing energy from its star to avoid freezing over,” said Victoria Meadows, an astrobiologist and planetary astronomer at the University of Washington. “Which is why this planet is still considered potentially habitable, as long as it has a dense enough atmosphere, even though it receives less light from its star than Mars does from our sun.”
She added, “It’s fun to note that if the planet is habitable, photosynthesis may be possible.”
At the wavelengths that plants need, Kepler 186f receives only about a sixth as much light as Earth does, but “there are plenty of Earth plants that would be quite happy with that,” Dr. Meadows said.
Astronomers cannot tell the exact age of the star, but such dwarfs are the longest-lived stars in the universe. If Kepler 186f is habitable, life would have had plenty of time — billions of years — to take hold.
But speculation about the planet will remain speculation for a long time, if not forever. The Kepler measurements indicated only the size of Kepler 186f. It is too far away for astronomers to discern its mass, much less whether it has an atmosphere and oceans or if it teems with living creatures.
Nonetheless, since dwarfs are the most plentiful type of star in the galaxy, astronomers are hopeful that Earth twins are plentiful, and that some will be found close by, allowing other telescopes to make temperature and mass measurements or to identify molecules in the atmosphere.
Kepler’s original mission ended last year, with the failure of equipment that kept the telescope precisely pointed, but scientists still have years of work in analyzing the data, which has so far yielded 962 confirmed planets. More than 2,800 planet candidates remain to be studied.
Correction: April 17, 2014
An earlier version of this article misstated the number of planet candidates found by Kepler that remain to be studied. It is 2,800, not 3,800.
It is a bit bigger and somewhat colder, but a planet circling a star 500 light-years away is otherwise the closest match of our home world discovered so far, astronomers announced on Thursday.
The planet, known as Kepler 186f, named after NASA’s Kepler planet-finding mission, which detected it, has a diameter of 8,700 miles, 10 percent wider than Earth, and its orbit lies within the “Goldilocks zone” of its star, Kepler 186 — not too hot, not too cold, where temperatures could allow for liquid water to flow at the surface, making it potentially hospitable for life.
“Kepler 186f is the first validated, Earth-size planet in the habitable zone of another star,” Elisa V. Quintana of the SETI Institute and NASA’s Ames Research Center in Mountain View, Calif., said at a news conference on Thursday. “It has the right size and is at the right distance to have properties similar to our home planet.”
Dr. Quintana is the lead author of a scientific paper describing the findings in this week’s issue of the journal Science. Kepler 186f is the latest planet to be sifted out of the voluminous data collected by Kepler, which kept watch over 150,000 stars, looking for slight drops in brightness when a planet passed in front.
This follows the announcement last year that another star, Kepler 62, has two planets in its habitable zone, but those two were “super Earths,” with masses probably several times that of Earth. The gravity of those planets might be strong enough to pull in helium and hydrogen gases, making them more like mini-Neptunes than large Earths.
With its smaller size, Kepler 186f is more likely to have an Earth-like rocky surface, another step in astronomers’ quest for what might be called Earth 2.0.
“It’s a progression,” said another member of the discovery team, Thomas S. Barclay of the Bay Area Environmental Research Institute. “This planet really reminds us of Earth.”
The researchers speculate that it is made of the same stuff as Earth — iron, rock, ice, liquid water, although the relative amounts could be very different.
The gravity on Kepler 186f, too, is likely to be roughly the same as Earth’s. “You could far more easily imagine someone being able to go there and walk around on the surface,” Stephen Kane, an astronomer at San Francisco State University and another member of the research team, said in an interview.
Kepler 186f is not a perfect replica, however. It is closer to its star — a red dwarf that is smaller, cooler and fainter than our sun — than the Earth is to its; its year, the time to complete one orbit, is 130 days, not 365. It is also at the outer edge of the habitable zone, receiving less warmth, so perhaps more of its surface would freeze.
“Perhaps it’s more of an Earth cousin than an Earth twin,” Dr. Barclay said.
On the other hand, with its greater mass, Kepler 186f could conceivably have a thicker, insulating atmosphere to compensate. Red dwarfs emit more of their light at the longer infrared wavelengths, which would be more readily absorbed and trapped by ice and gases like water vapor and carbon dioxide.
“This makes the planet more efficient at absorbing energy from its star to avoid freezing over,” said Victoria Meadows, an astrobiologist and planetary astronomer at the University of Washington. “Which is why this planet is still considered potentially habitable, as long as it has a dense enough atmosphere, even though it receives less light from its star than Mars does from our sun.”
She added, “It’s fun to note that if the planet is habitable, photosynthesis may be possible.”
At the wavelengths that plants need, Kepler 186f receives only about a sixth as much light as Earth does, but “there are plenty of Earth plants that would be quite happy with that,” Dr. Meadows said.
Astronomers cannot tell the exact age of the star, but such dwarfs are the longest-lived stars in the universe. If Kepler 186f is habitable, life would have had plenty of time — billions of years — to take hold.
But speculation about the planet will remain speculation for a long time, if not forever. The Kepler measurements indicated only the size of Kepler 186f. It is too far away for astronomers to discern its mass, much less whether it has an atmosphere and oceans or if it teems with living creatures.
Nonetheless, since dwarfs are the most plentiful type of star in the galaxy, astronomers are hopeful that Earth twins are plentiful, and that some will be found close by, allowing other telescopes to make temperature and mass measurements or to identify molecules in the atmosphere.
Kepler’s original mission ended last year, with the failure of equipment that kept the telescope precisely pointed, but scientists still have years of work in analyzing the data, which has so far yielded 962 confirmed planets. More than 2,800 planet candidates remain to be studied.
Correction: April 17, 2014
An earlier version of this article misstated the number of planet candidates found by Kepler that remain to be studied. It is 2,800, not 3,800.
Traffic Pollution, Noise Linked to Heart Diseases: Study
Exposure to traffic pollution and noise can in the long run lead to atherosclerosis, according to a German study which for the first time explored the links between the two.
The study, which was based on data from the German Heinz Nixdorf Recall Study, calculated the long-term exposure to particle pollutants of 4,814 participants who live nearby roads with high traffic volume.
The results were presented at a European Society for Cardiology event in Rome on Thursday (18 April). For the first time, the cardiological study also took account of road traffic noise and its effect on cardiovascular diseases, as recorded by validated tests. The test group's level of atherosclerosis was then evaluated by measurement of vascular vessel calcification in the thoracic aorta by computed imaging. Results showed that in 4,238 subjects small particulate matter and proximity to major roads were both associated with an increasing level of aortic calcification. For every increase in particle volume up to 2.4 micrometres, the degree of calcification increased by 20.7% and went up an extra 10% for every 100 metre of proximity to heavy traffic.
The study, which was based on data from the German Heinz Nixdorf Recall Study, calculated the long-term exposure to particle pollutants of 4,814 participants who live nearby roads with high traffic volume.
The results were presented at a European Society for Cardiology event in Rome on Thursday (18 April). For the first time, the cardiological study also took account of road traffic noise and its effect on cardiovascular diseases, as recorded by validated tests. The test group's level of atherosclerosis was then evaluated by measurement of vascular vessel calcification in the thoracic aorta by computed imaging. Results showed that in 4,238 subjects small particulate matter and proximity to major roads were both associated with an increasing level of aortic calcification. For every increase in particle volume up to 2.4 micrometres, the degree of calcification increased by 20.7% and went up an extra 10% for every 100 metre of proximity to heavy traffic.
Traffic noise associated with increased risk of heart attack. The study also found a increase in atherosclerosis associated with night time noise.
Dr Hagen Kälsch from the West-German Heart Centre in Essen said that long-term exposure to fine particle matter air pollution and to road traffic noise are both independently associated with subclinical atherosclerosis. "These two major types of traffic emissions help explain the observed associations between living close to high traffic and subclinical atherosclerosis. The considerable size of the associations underscores the importance of long-term exposure to air pollution and road traffic noise as risk factors for atherosclerosis," Kälsch said.
The association between road traffic and heart disease has been suggested in previous studies. In 2013 a study from Denmark showed that traffic noise was significantly associated with risk of heart attack. For every 10 decibel increase in noise exposure, there was a 12% increased risk, the study found.
Dr Hagen Kälsch from the West-German Heart Centre in Essen said that long-term exposure to fine particle matter air pollution and to road traffic noise are both independently associated with subclinical atherosclerosis. "These two major types of traffic emissions help explain the observed associations between living close to high traffic and subclinical atherosclerosis. The considerable size of the associations underscores the importance of long-term exposure to air pollution and road traffic noise as risk factors for atherosclerosis," Kälsch said.
The association between road traffic and heart disease has been suggested in previous studies. In 2013 a study from Denmark showed that traffic noise was significantly associated with risk of heart attack. For every 10 decibel increase in noise exposure, there was a 12% increased risk, the study found.
Fine particle matter and traffic noise are believed to act through similar biologic pathways, thereby increasing cardiovascular risk. They both cause an imbalance in the autonomic nervous system, which feeds into the complex mechanisms regulating blood pressure, blood lipids, and glucose level.
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