Photo by C.B. Devgun.
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Photo by C.B. Devgun.
from EarthSky http://ift.tt/2zJiuiJ
Birds and sun, New Delhi, India
from EarthSky http://ift.tt/2zJiuiJ
from EarthSky http://ift.tt/2zJiuiJ
Sky Bear comes to Earth in November
Tonight … a constellation you might or might not see, depending on your latitude. In the Northern Hemisphere, the Big Dipper is probably the sky’s best known asterism. In other words, it’s a recognizable pattern of stars – not an official constellation. The Big Dipper is part of the constellation Ursa Major, otherwise known as the Great Bear.
Every year, the Big Dipper (Great Bear) descends to its lowest point in the sky on November evenings. In fact, people in the southern part of the United States can’t see the Big Dipper in the evening right now, because it swings beneath their northern horizon.
And, of course, it can’t be seen in the evening from Southern Hemisphere latitudes now either.
Image Credit: AlltheSky.com
Even in the northern states, the Big Bear is hard to spot. The Big Dipper skims along the northern horizon in the evening, ducking behind any obstructions – such as trees and mountains.
To the Micmac Indians living in southeast Canada, a Celestial Bear – our same familiar Big Dipper pattern – coming down to Earth signaled the start of hibernation season. This is when earthly bears return to their dens, and when the sap of trees returns to the warm womb of the underworld. Weary creation tucks in, waiting for winter’s deep slumber.
The Micmacs saw the Big Dipper handle stars as hunters forever chasing Celestial Bear. In their sky lore, hunters catch Celestial Bear each year in the fall, and it’s the dripping blood from the Bear that colors the autumn landscape.
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View larger. | Another portrayal of the Big Dipper in November. It’s Vincent van Gogh’s Starry Night Over the Rhone, painted in September 1888 at Arles. Had you noticed the Big Dipper in this painting? Can you see it tonight?
Bottom line: The Big Dipper is difficult, or impossible, to see on November evenings. If you’re in the southern U.S. or a similar latitude around the world, the Dipper is below your northern horizon in the evening now. If you’re in the northern U.S. or a similar latitude, the Big Dipper may be above your horizon in the evening, but it will be low in the northern sky.
November 2017 guide to the five visible planets
EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!
Donate: Your support means the world to us
from EarthSky http://ift.tt/1H43FG5
Tonight … a constellation you might or might not see, depending on your latitude. In the Northern Hemisphere, the Big Dipper is probably the sky’s best known asterism. In other words, it’s a recognizable pattern of stars – not an official constellation. The Big Dipper is part of the constellation Ursa Major, otherwise known as the Great Bear.
Every year, the Big Dipper (Great Bear) descends to its lowest point in the sky on November evenings. In fact, people in the southern part of the United States can’t see the Big Dipper in the evening right now, because it swings beneath their northern horizon.
And, of course, it can’t be seen in the evening from Southern Hemisphere latitudes now either.
Image Credit: AlltheSky.com
Even in the northern states, the Big Bear is hard to spot. The Big Dipper skims along the northern horizon in the evening, ducking behind any obstructions – such as trees and mountains.
To the Micmac Indians living in southeast Canada, a Celestial Bear – our same familiar Big Dipper pattern – coming down to Earth signaled the start of hibernation season. This is when earthly bears return to their dens, and when the sap of trees returns to the warm womb of the underworld. Weary creation tucks in, waiting for winter’s deep slumber.
The Micmacs saw the Big Dipper handle stars as hunters forever chasing Celestial Bear. In their sky lore, hunters catch Celestial Bear each year in the fall, and it’s the dripping blood from the Bear that colors the autumn landscape.
Donate: Your support means the world to us
View larger. | Another portrayal of the Big Dipper in November. It’s Vincent van Gogh’s Starry Night Over the Rhone, painted in September 1888 at Arles. Had you noticed the Big Dipper in this painting? Can you see it tonight?
Bottom line: The Big Dipper is difficult, or impossible, to see on November evenings. If you’re in the southern U.S. or a similar latitude around the world, the Dipper is below your northern horizon in the evening now. If you’re in the northern U.S. or a similar latitude, the Big Dipper may be above your horizon in the evening, but it will be low in the northern sky.
November 2017 guide to the five visible planets
EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!
Donate: Your support means the world to us
from EarthSky http://ift.tt/1H43FG5
The zombie star that wouldn’t die
Artist’s concept of a supernova explosion via ESO/ M. Kornmesser.
Powerful star explosions known as supernovae usually mark the death of stars. But astronomers today (November 8, 2017) announced a supernova that exploded multiple times over a period of more than 50 years. It might be the explosion of a star more massive than any seen to explode before. It might be an explosion caused by the meeting of matter and antimatter in a massive star’s core. Whatever the true explanation, the astronomers said the finding, which is published in the peer-reviewed journal Nature:
… completely confounds existing knowledge of a star’s end of life.
The Palomar Transient Factory – an astronomical survey led by Caltech designed to find transient and variable sources such as variable stars, supernovae, asteroids and comets – noticed this supernova in September of 2014. The supernova was designated iPTF14hls. Analysis of its light indicated it was what’s called a type II-P supernova. As expected, the supernova began to fade again.
Everything about the discovery seemed normal … until a few months later.
That’s when astronomers with the Las Cumbres Observatory – a worldwide network of robotic telescopes, directed out of Goleta, California – noticed that iPTF14hls was growing brighter again. Their statement explained:
A normal supernova rises to peak brightness and fades over approximately 100 days. Supernova iPTF14hls, on the other hand, grew brighter and dimmer at least five times over two years.
Then astronomers went back and looked at archival data, showing this part of the sky. They were astonished to find evidence of an explosion in 1954 at the exact same location on the sky’s dome. Apparently, iPTF14hls had somehow survived an earlier explosion and exploded again in 2014.
An image taken by the Palomar Observatory Sky Survey revealed a possible explosion in the year 1954 at the location of iPTF14hls (left), not seen in a later image taken in 1993 (right). Supernovae are known to explode only once, shine for a few months and then fade, but iPTF14hls experienced at least 2 explosions, 60 years apart. Image adapted from Arcavi et al. 2017, Nature, via POSS/ DSS/ LCO/ S. Wilkinson/ CarnegieScience.edu.
Astronomers are now saying that iPTF14hls might be an explosion of a star more massive than any seen to explode before. The study – led by astronomer Iair Arcavi, of Las Cumbres Observatory and the University of California, Santa Barbara – calculated that the star that exploded was at least 50 times more massive than our sun and probably much larger. The size of this explosion could be the reason that our conventional understanding of the death of stars failed to explain this event, according to these astronomers. Iair Arcavi commented:
This supernova breaks everything we thought we knew about how [supernovae] work.
The Las Cumbres astronomers’ statement also explained a possible bizarre mechanism for the explosion of Supernova iPTF14hls:
Supernova iPTF14hls may be the first example of a ‘pulsational pair instability supernova.’ This theory holds that massive stars become so hot in their cores that energy is converted into matter and antimatter. This would cause an explosion that blows off the outer layers of the star and leaves the core intact; this process can repeat over decades before the large final explosion and collapse to a black hole.
Andy Howell, leader of the LCO supernova group and a coauthor of the study, said:
These explosions were only expected to be seen in the early universe and should be extinct today. This is like finding a dinosaur still alive today. If you found one, you would question whether it truly was a dinosaur.
But, the astronomers warn, this theory can’t explain all the observations and might not, after all, be the answer to the riddle of this star. Instead, they say, this supernova might be something completely new.
That’s why the supernova group at Las Cumbres Observatory is still monitoring iPTF14hls, which remains bright three years after it was discovered.
Supernova iPTF14hls grew bright and dim again at least 5 times over 2 years. Image adapted from Arcavi et al. 2017, Nature, via LCO/ S. Wilkinson/ CarnegieScience.edu.
Bottom line: Supernovae iPTF14hls – discovered in 2014 – stayed bright for 600 days. Then, astronomers found a 1954 explosion in the same spot in the sky.
Via Las Cumbres Observatory and Carnegie Science.
from EarthSky http://ift.tt/2iGdMHv
Artist’s concept of a supernova explosion via ESO/ M. Kornmesser.
Powerful star explosions known as supernovae usually mark the death of stars. But astronomers today (November 8, 2017) announced a supernova that exploded multiple times over a period of more than 50 years. It might be the explosion of a star more massive than any seen to explode before. It might be an explosion caused by the meeting of matter and antimatter in a massive star’s core. Whatever the true explanation, the astronomers said the finding, which is published in the peer-reviewed journal Nature:
… completely confounds existing knowledge of a star’s end of life.
The Palomar Transient Factory – an astronomical survey led by Caltech designed to find transient and variable sources such as variable stars, supernovae, asteroids and comets – noticed this supernova in September of 2014. The supernova was designated iPTF14hls. Analysis of its light indicated it was what’s called a type II-P supernova. As expected, the supernova began to fade again.
Everything about the discovery seemed normal … until a few months later.
That’s when astronomers with the Las Cumbres Observatory – a worldwide network of robotic telescopes, directed out of Goleta, California – noticed that iPTF14hls was growing brighter again. Their statement explained:
A normal supernova rises to peak brightness and fades over approximately 100 days. Supernova iPTF14hls, on the other hand, grew brighter and dimmer at least five times over two years.
Then astronomers went back and looked at archival data, showing this part of the sky. They were astonished to find evidence of an explosion in 1954 at the exact same location on the sky’s dome. Apparently, iPTF14hls had somehow survived an earlier explosion and exploded again in 2014.
An image taken by the Palomar Observatory Sky Survey revealed a possible explosion in the year 1954 at the location of iPTF14hls (left), not seen in a later image taken in 1993 (right). Supernovae are known to explode only once, shine for a few months and then fade, but iPTF14hls experienced at least 2 explosions, 60 years apart. Image adapted from Arcavi et al. 2017, Nature, via POSS/ DSS/ LCO/ S. Wilkinson/ CarnegieScience.edu.
Astronomers are now saying that iPTF14hls might be an explosion of a star more massive than any seen to explode before. The study – led by astronomer Iair Arcavi, of Las Cumbres Observatory and the University of California, Santa Barbara – calculated that the star that exploded was at least 50 times more massive than our sun and probably much larger. The size of this explosion could be the reason that our conventional understanding of the death of stars failed to explain this event, according to these astronomers. Iair Arcavi commented:
This supernova breaks everything we thought we knew about how [supernovae] work.
The Las Cumbres astronomers’ statement also explained a possible bizarre mechanism for the explosion of Supernova iPTF14hls:
Supernova iPTF14hls may be the first example of a ‘pulsational pair instability supernova.’ This theory holds that massive stars become so hot in their cores that energy is converted into matter and antimatter. This would cause an explosion that blows off the outer layers of the star and leaves the core intact; this process can repeat over decades before the large final explosion and collapse to a black hole.
Andy Howell, leader of the LCO supernova group and a coauthor of the study, said:
These explosions were only expected to be seen in the early universe and should be extinct today. This is like finding a dinosaur still alive today. If you found one, you would question whether it truly was a dinosaur.
But, the astronomers warn, this theory can’t explain all the observations and might not, after all, be the answer to the riddle of this star. Instead, they say, this supernova might be something completely new.
That’s why the supernova group at Las Cumbres Observatory is still monitoring iPTF14hls, which remains bright three years after it was discovered.
Supernova iPTF14hls grew bright and dim again at least 5 times over 2 years. Image adapted from Arcavi et al. 2017, Nature, via LCO/ S. Wilkinson/ CarnegieScience.edu.
Bottom line: Supernovae iPTF14hls – discovered in 2014 – stayed bright for 600 days. Then, astronomers found a 1954 explosion in the same spot in the sky.
Via Las Cumbres Observatory and Carnegie Science.
from EarthSky http://ift.tt/2iGdMHv
It’s National STEM Day! Here Are 5 Ways DoD Makes STEM Cool
Want birds in your yard? Plant native trees
A Carolina chickadee with a juicy caterpillar. Photo courtesy of Desiree Narango and Doug Tallamy.
Students of nature learn that the natural world is deeply interconnected. For example, the food web that sustains wild birds is highly dependent on plant species that host insects. A recently published study – focused on yards in the Washington, D.C. metro area – shows that native trees and shrubs were the best producers of caterpillars and other insects that are valuable as food for wild birds. The study, by scientists at the University of Delaware and the Smithsonian Migratory Bird Center, appeared in the journal Biological Conservation.
Desiree Narango, a doctoral student at the University of Delaware, is the paper’s lead author. She works with Doug Tallamy, a professor of entomology at the university’s Department of Entomology and Wildlife Ecology. Tallamy is the author of Bringing Nature Home, a 2007 book that makes a strong case for growing native plants in home gardens to help support wildlife that face dwindling natural habitats. Narango’s work is also associated with a citizen-science program called “Neighborhood Nest Watch,” run by the Smithsonian Migratory Bird Center.
Over ninety percent of insect species co-evolved with a specific plant species or a group of related plant species; their larvae — caterpillars — adapted over the insect’s evolutionary history to overcome the chemical defenses of its host plant(s). These insects, however, have not had a chance to develop a tolerance for the chemical defenses in many recently-introduced plants, and are therefore unable to consume them.
In the video above, Doug Tallamy talks about why native plants matter (duration: 3 minutes 50 seconds).
During the breeding season, birds depend on insects, a rich source of protein, to feed their young. Over a four-year span, Narango and her team observed where breeding birds foraged for food in 203 yards of homes in the Washington D.C. metropolitan area. She documented which plants provided the most food, such as insects and caterpillars, for the birds.
In a press release, Narango said:
We just had a paper come out in the journal of Biological Conservation where we show that native trees are better at providing caterpillars for birds, which is a really important food resource. Native trees are better, hands down, but even among the native trees, there are some that are better than others [in the in the Washington, D.C. metro area] so things like oaks and cherries and elms are highly productive for caterpillars. They have lots of good food for the birds.
Desiree Narango, a doctoral student at the University of Delaware, holding a white-breasted nuthatch. Photo courtesy of Desiree Narango and Doug Tallamy.
Narango said she was struck by the large variety of different trees she encountered in the gardens:
We focus on woody plants — so trees and shrubs — and we’ve documented over 375 different species in these 203 yards. Which is crazy.
Most non-native plants, such as zelkova, ginkgo and lilac, did not provide any food for breeding birds. Narango said:
Those species are true non-natives so they’re not related to anything here, and they provide almost nothing in terms of caterpillars for birds. There are also species like Japanese cherry and Japanese maple that are non-native but are related to our native maples and cherries. We found that those species have an average of 40 percent fewer caterpillars than the native versions of that tree. If you had a choice between a black cherry and a Japanese cherry and if you’re interested in food for birds, then you should choose the native version.
Narango was also struck by the large diversity in insects and birds she encountered. Ninety-eight different bird species were documented in the study. She commented:
A lot of people think you need to go to the woods to see beautiful butterflies or beautiful birds, but they’re actually in people’s backyards, too.
In her study, Narango observed individual Carolina chickadees, following them to see which trees they chose to forage for food. Chickadees, it turned out, preferred trees that supported the most caterpillar species.
When these birds would choose a tree, all the other birds in the neighborhood were choosing those trees, too. So we would see these amazing warblers that don’t breed in Delaware or in D.C. but are migrating through, and they’re using all these suburban habitats on their way north. In a way, our chickadees were telling us what all of the birds want during that period.
Most homeowners interested in growing native plants, however, face the challenge of finding them because many big box stores don’t sell them. However, she noted:
There are a lot of really great small nurseries that have many native plants that are productive in terms of caterpillars and are also very beautiful. You definitely don’t have to sacrifice beauty to get plants that are ecologically beneficial. There’s a lot to choose from so you can have beauty, you can have fruit and then also have food for birds, too. It’s all interconnected.
Narango, who is also a landscaper, said she was personally surprised by the increased wildlife activity in her own backyard when she started growing native plants.
I planted this flower called ironweed, and the first year it was there, I had the specialist bees that use that flower and then I have caterpillars in my shrubs, and it’s really cool how quickly you can see life be attracted to your yard when you plant the right species.
A White Oak Tree in Manchester, Maryland. Image courtesy Mopenstein via Wikimedia Commons.
Bottom line: Wild birds in suburban areas are highly dependent on native plants that host insects that are an important source of their food.
from EarthSky http://ift.tt/2AsKzYE
A Carolina chickadee with a juicy caterpillar. Photo courtesy of Desiree Narango and Doug Tallamy.
Students of nature learn that the natural world is deeply interconnected. For example, the food web that sustains wild birds is highly dependent on plant species that host insects. A recently published study – focused on yards in the Washington, D.C. metro area – shows that native trees and shrubs were the best producers of caterpillars and other insects that are valuable as food for wild birds. The study, by scientists at the University of Delaware and the Smithsonian Migratory Bird Center, appeared in the journal Biological Conservation.
Desiree Narango, a doctoral student at the University of Delaware, is the paper’s lead author. She works with Doug Tallamy, a professor of entomology at the university’s Department of Entomology and Wildlife Ecology. Tallamy is the author of Bringing Nature Home, a 2007 book that makes a strong case for growing native plants in home gardens to help support wildlife that face dwindling natural habitats. Narango’s work is also associated with a citizen-science program called “Neighborhood Nest Watch,” run by the Smithsonian Migratory Bird Center.
Over ninety percent of insect species co-evolved with a specific plant species or a group of related plant species; their larvae — caterpillars — adapted over the insect’s evolutionary history to overcome the chemical defenses of its host plant(s). These insects, however, have not had a chance to develop a tolerance for the chemical defenses in many recently-introduced plants, and are therefore unable to consume them.
In the video above, Doug Tallamy talks about why native plants matter (duration: 3 minutes 50 seconds).
During the breeding season, birds depend on insects, a rich source of protein, to feed their young. Over a four-year span, Narango and her team observed where breeding birds foraged for food in 203 yards of homes in the Washington D.C. metropolitan area. She documented which plants provided the most food, such as insects and caterpillars, for the birds.
In a press release, Narango said:
We just had a paper come out in the journal of Biological Conservation where we show that native trees are better at providing caterpillars for birds, which is a really important food resource. Native trees are better, hands down, but even among the native trees, there are some that are better than others [in the in the Washington, D.C. metro area] so things like oaks and cherries and elms are highly productive for caterpillars. They have lots of good food for the birds.
Desiree Narango, a doctoral student at the University of Delaware, holding a white-breasted nuthatch. Photo courtesy of Desiree Narango and Doug Tallamy.
Narango said she was struck by the large variety of different trees she encountered in the gardens:
We focus on woody plants — so trees and shrubs — and we’ve documented over 375 different species in these 203 yards. Which is crazy.
Most non-native plants, such as zelkova, ginkgo and lilac, did not provide any food for breeding birds. Narango said:
Those species are true non-natives so they’re not related to anything here, and they provide almost nothing in terms of caterpillars for birds. There are also species like Japanese cherry and Japanese maple that are non-native but are related to our native maples and cherries. We found that those species have an average of 40 percent fewer caterpillars than the native versions of that tree. If you had a choice between a black cherry and a Japanese cherry and if you’re interested in food for birds, then you should choose the native version.
Narango was also struck by the large diversity in insects and birds she encountered. Ninety-eight different bird species were documented in the study. She commented:
A lot of people think you need to go to the woods to see beautiful butterflies or beautiful birds, but they’re actually in people’s backyards, too.
In her study, Narango observed individual Carolina chickadees, following them to see which trees they chose to forage for food. Chickadees, it turned out, preferred trees that supported the most caterpillar species.
When these birds would choose a tree, all the other birds in the neighborhood were choosing those trees, too. So we would see these amazing warblers that don’t breed in Delaware or in D.C. but are migrating through, and they’re using all these suburban habitats on their way north. In a way, our chickadees were telling us what all of the birds want during that period.
Most homeowners interested in growing native plants, however, face the challenge of finding them because many big box stores don’t sell them. However, she noted:
There are a lot of really great small nurseries that have many native plants that are productive in terms of caterpillars and are also very beautiful. You definitely don’t have to sacrifice beauty to get plants that are ecologically beneficial. There’s a lot to choose from so you can have beauty, you can have fruit and then also have food for birds, too. It’s all interconnected.
Narango, who is also a landscaper, said she was personally surprised by the increased wildlife activity in her own backyard when she started growing native plants.
I planted this flower called ironweed, and the first year it was there, I had the specialist bees that use that flower and then I have caterpillars in my shrubs, and it’s really cool how quickly you can see life be attracted to your yard when you plant the right species.
A White Oak Tree in Manchester, Maryland. Image courtesy Mopenstein via Wikimedia Commons.
Bottom line: Wild birds in suburban areas are highly dependent on native plants that host insects that are an important source of their food.
from EarthSky http://ift.tt/2AsKzYE
Why trees shed their leaves
November 2017 on Maple Street in Johnson City, Tennessee. Image via Teri Butler Dosher.
In temperate forests across the Northern Hemisphere, trees shed their leaves during autumn as cold weather approaches. In tropical and subtropical forests, trees shed their leaves at the onset of the dry season. Many types of trees shed their leaves as a strategy to survive harsh weather conditions. Trees that lose all of their leaves for part of the year are known as deciduous trees. Those that don’t are called evergreen trees.
Common deciduous trees in the Northern Hemisphere include several species of ash, aspen, beech, birch, cherry, elm, hickory, hornbeam, maple, oak, poplar and willow. In tropical and subtropical regions, deciduous trees include several species of acacia, baobab, roble, ceiba, chaca and guanacaste.
Image via Tosca Yemoh Zanon in London
Photo via Daniel de Leeuw Photography
Most deciduous trees have broad leaves that are susceptible to being damaged during cold or dry weather. In contrast, most evergreen trees either live in warm, wet climates or they have weather-resistant needles for leaves. However, there are exceptions in nature, such as tamarack trees that shed their needles every autumn and live oaks that retain their broad leaves for the entire year even in relatively cool climates.
Shedding leaves helps trees to conserve water and energy. As unfavorable weather approaches, hormones in the trees trigger the process of abscission whereby the leaves are actively cut-off of the tree by specialized cells. The word abscission shares the same Latin root word as that in scissors, scindere, which means “to cut.” At the start of the abscission process, trees reabsorb valuable nutrients from their leaves and store them for later use in their roots. Chlorophyll, the pigment that gives leaves their green color, is one of the first molecules to be broken down for its nutrients. This is one of the reasons why trees turn red, orange, and gold colors during the fall. At the end of the abscission process, when the leaves have been shed, a protective layer of cells grows over the exposed area.
Layer of abscission cells separating a leaf from its stem. Image Credit: U.S. Forest Service.
The shedding of leaves may also help trees to pollinate come springtime. Without leaves to get in the way, wind-blown pollen can travel longer distances and reach more trees.
Autumn leaves. Image Credit: Tracy Ducasse.
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Bottom line: Many types of trees shed their leaves as a strategy to survive cold or dry weather.
from EarthSky http://ift.tt/1jAb98D
November 2017 on Maple Street in Johnson City, Tennessee. Image via Teri Butler Dosher.
In temperate forests across the Northern Hemisphere, trees shed their leaves during autumn as cold weather approaches. In tropical and subtropical forests, trees shed their leaves at the onset of the dry season. Many types of trees shed their leaves as a strategy to survive harsh weather conditions. Trees that lose all of their leaves for part of the year are known as deciduous trees. Those that don’t are called evergreen trees.
Common deciduous trees in the Northern Hemisphere include several species of ash, aspen, beech, birch, cherry, elm, hickory, hornbeam, maple, oak, poplar and willow. In tropical and subtropical regions, deciduous trees include several species of acacia, baobab, roble, ceiba, chaca and guanacaste.
Image via Tosca Yemoh Zanon in London
Photo via Daniel de Leeuw Photography
Most deciduous trees have broad leaves that are susceptible to being damaged during cold or dry weather. In contrast, most evergreen trees either live in warm, wet climates or they have weather-resistant needles for leaves. However, there are exceptions in nature, such as tamarack trees that shed their needles every autumn and live oaks that retain their broad leaves for the entire year even in relatively cool climates.
Shedding leaves helps trees to conserve water and energy. As unfavorable weather approaches, hormones in the trees trigger the process of abscission whereby the leaves are actively cut-off of the tree by specialized cells. The word abscission shares the same Latin root word as that in scissors, scindere, which means “to cut.” At the start of the abscission process, trees reabsorb valuable nutrients from their leaves and store them for later use in their roots. Chlorophyll, the pigment that gives leaves their green color, is one of the first molecules to be broken down for its nutrients. This is one of the reasons why trees turn red, orange, and gold colors during the fall. At the end of the abscission process, when the leaves have been shed, a protective layer of cells grows over the exposed area.
Layer of abscission cells separating a leaf from its stem. Image Credit: U.S. Forest Service.
The shedding of leaves may also help trees to pollinate come springtime. Without leaves to get in the way, wind-blown pollen can travel longer distances and reach more trees.
Autumn leaves. Image Credit: Tracy Ducasse.
Enjoying EarthSky? Sign up for our free daily newsletter today!
Bottom line: Many types of trees shed their leaves as a strategy to survive cold or dry weather.
from EarthSky http://ift.tt/1jAb98D
NCRI 2017: How knowing tumours inside and out is boosting progress
If you’ve noticed that the media has been abuzz with the word cancer recently, that’s not by coincidence. Scientists have been revealing their latest findings in a string of conferences all across the globe, from Lisbon’s Advanced Breast Cancer Fourth International Consensus to the International Conference on Molecular Targets and Cancer Therapeutics in Philadelphia.
Over the past few days, Liverpool has been the source of that media excitement, housing the 13th annual National Cancer Research Institute (NCRI) Cancer Conference. The NCRI is a UK-wide partnership of various cancer research funders, including Cancer Research UK, and since coming together in 2002 these collaborators have spent a staggering £6 billion on science, said the organisation’s director Dr Karen Kennedy during her opening speech.
Without funding, research wouldn’t be possible, and the science that’s been shared throughout the NCRI conference shows the real progress that’s being made against cancer thanks to research. And this progress was reflected across the science on show, ranging from prevention to diagnosis and treatment research.
But despite this diversity, many of the presenters had something in common: they want to know tumours inside and out, from the tiny genetic changes that fuel the cancer’s growth to its complex surroundings that battle with the immune system.
So what are scientists doing to get to know cancer better?
All about that base
Cancer is rooted in DNA, so it’s unsurprising that scientists are investing a lot of effort in combing through the long strings of DNA ‘letters’ – or bases – that carry tumour cells’ genetic code. And improvements in technology are allowing scientists to gather more information from this than they ever dreamed of. Dr Jonathan McHugh from the University of Michigan in the US, said that in 2003 it cost $3,000,000,000 to crack the human genetic code for the first time. Now the same feat can be achieved for less than $1,000.
“These advances allow us to look deeper,” he said. “Defining a tumour by the organ it originated in is no longer sufficient – we need to understand the genetics of each patient’s tumour, figuring out which genes are important and trying to find the best treatment plan.”
NCRI in the news
- Artificial intelligence could predict risk of radiotherapy side effects
- Test could spot food pipe cancer 8 years earlier
- Ovarian cancer drug can reach brain tumours
- Testosterone levels linked with prostate cancer risk
- More women than men diagnosed with bowel cancer as an emergency
Using a tumour’s genetic information to select the best treatment and predict how the disease might progress is one of the major ways that scientists are hoping to improve cancer care. But there are many different ways to gather such information. Dr Andrew Beggs, from the University of Birmingham and funded by Cancer Research UK, spoke of how his team is studying patterns of chemical tags found on DNA letters – called methyl groups – which can affect how a gene behaves, to help better characterise patients’ tumours. And he’s not limiting himself to cells within tumours – he’s also using patient samples to scour through the DNA of cells that have broken away and made their way into the blood.
Another pattern scientists can look for is specific changes to the letters of tumour DNA, such as ‘spelling mistakes’ where the wrong base has been added in, or it’s missing altogether. Studying these alterations can reveal what caused the cancer, as harmful substances and chemicals leave distinct patterns or ‘signatures’ that scientists can spot by studying tumour samples.
One signature that recently caused a stir was identified by speaker Dr Bin Tean Teh, from the National Cancer Centre of Singapore. He discovered that a group of molecules called aristolochic acids, which are found in several plant species commonly used in traditional Chinese medicine, are potent cancer-causing chemicals. He’s found that the distinct signatures they leave are appearing in many cancers, particularly in areas of the world where Chinese medicine is common, and is calling for a ban on the sale of such plants in medicine.
This work highlights the importance of studying these signatures, because knowing the causes of cancers could help prevent cases in the future if there are ways to limit exposure.
Causes to consequences
As well as looking at the origins of genetic changes, researchers are also studying and exploiting their consequences. Genes contain the recipes for the proteins that make up cells, and changes to the recipes can affect how these proteins look and work. As the immune system is designed to recognise things out of the ordinary, scientists are finding that the level of genetic chaos within a tumour can affect how the immune system ‘sees’ a tumour.
Using patient samples, Dr Vinod Balachandran, from the Parker Institute in the US, has found that some alterations to proteins caused by genetic changes in pancreatic cancer are better at alerting the immune system than others. Assessing the ‘quality’ of these molecules, he said, could help guide the development of new immunotherapies to better equip the immune system to attack the cancer.
2017 Cancer Research UK Research Prizes
- Future Leaders: Dr Gerhardt Attard, Dr Simon Leedham, Dr Santiago Zelenay
- Jane Wardle Prize: Prof Greg Rubin
- Translational Cancer Research Prize: Tumour heterogeneity team
Find out more here.
While other presenters on pancreatic cancer discussed different opportunities and challenges for this disease, they all shared a sense of urgency.
“Around 90% of patients will die within a year, and the average survival is just 6 months,” said Professor Andrew Biankin, a Cancer Research UK-funded pancreatic cancer expert from the University of Glasgow. “These are things I’d like to see change.”
Balachandran and others are also studying the immune cells within and around patients’ tumours to try and find out why some can attack cancer cells while others fail. Through his work at the University of Southampton, Professor Gareth Thomas has found one obstacle to an effective attack: cancer-associated fibroblasts. These are healthy cells that become coerced into helping the tumour, and through his work in the lab Thomas has discovered that these cells can form a protective barrier that blocks immune cells.
Clearing hurdles
The diversity of research presented at NCRI serves as a reminder that there is no single solution to cancer, and that to make progress in beating the disease we need to attack it from all angles – and in smarter ways. That’s why collaboration is so important to make progress, a point that echoed throughout this year’s conference.
But as always, the research showcased gives plenty of room for hope, as well as inspiration to keep up the hard work. And the more heads that continue to come together, the more pieces of this complex puzzle will begin to slot into place, bringing solutions closer every day.
Justine
from Cancer Research UK – Science blog http://ift.tt/2m0Zvdg
If you’ve noticed that the media has been abuzz with the word cancer recently, that’s not by coincidence. Scientists have been revealing their latest findings in a string of conferences all across the globe, from Lisbon’s Advanced Breast Cancer Fourth International Consensus to the International Conference on Molecular Targets and Cancer Therapeutics in Philadelphia.
Over the past few days, Liverpool has been the source of that media excitement, housing the 13th annual National Cancer Research Institute (NCRI) Cancer Conference. The NCRI is a UK-wide partnership of various cancer research funders, including Cancer Research UK, and since coming together in 2002 these collaborators have spent a staggering £6 billion on science, said the organisation’s director Dr Karen Kennedy during her opening speech.
Without funding, research wouldn’t be possible, and the science that’s been shared throughout the NCRI conference shows the real progress that’s being made against cancer thanks to research. And this progress was reflected across the science on show, ranging from prevention to diagnosis and treatment research.
But despite this diversity, many of the presenters had something in common: they want to know tumours inside and out, from the tiny genetic changes that fuel the cancer’s growth to its complex surroundings that battle with the immune system.
So what are scientists doing to get to know cancer better?
All about that base
Cancer is rooted in DNA, so it’s unsurprising that scientists are investing a lot of effort in combing through the long strings of DNA ‘letters’ – or bases – that carry tumour cells’ genetic code. And improvements in technology are allowing scientists to gather more information from this than they ever dreamed of. Dr Jonathan McHugh from the University of Michigan in the US, said that in 2003 it cost $3,000,000,000 to crack the human genetic code for the first time. Now the same feat can be achieved for less than $1,000.
“These advances allow us to look deeper,” he said. “Defining a tumour by the organ it originated in is no longer sufficient – we need to understand the genetics of each patient’s tumour, figuring out which genes are important and trying to find the best treatment plan.”
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Using a tumour’s genetic information to select the best treatment and predict how the disease might progress is one of the major ways that scientists are hoping to improve cancer care. But there are many different ways to gather such information. Dr Andrew Beggs, from the University of Birmingham and funded by Cancer Research UK, spoke of how his team is studying patterns of chemical tags found on DNA letters – called methyl groups – which can affect how a gene behaves, to help better characterise patients’ tumours. And he’s not limiting himself to cells within tumours – he’s also using patient samples to scour through the DNA of cells that have broken away and made their way into the blood.
Another pattern scientists can look for is specific changes to the letters of tumour DNA, such as ‘spelling mistakes’ where the wrong base has been added in, or it’s missing altogether. Studying these alterations can reveal what caused the cancer, as harmful substances and chemicals leave distinct patterns or ‘signatures’ that scientists can spot by studying tumour samples.
One signature that recently caused a stir was identified by speaker Dr Bin Tean Teh, from the National Cancer Centre of Singapore. He discovered that a group of molecules called aristolochic acids, which are found in several plant species commonly used in traditional Chinese medicine, are potent cancer-causing chemicals. He’s found that the distinct signatures they leave are appearing in many cancers, particularly in areas of the world where Chinese medicine is common, and is calling for a ban on the sale of such plants in medicine.
This work highlights the importance of studying these signatures, because knowing the causes of cancers could help prevent cases in the future if there are ways to limit exposure.
Causes to consequences
As well as looking at the origins of genetic changes, researchers are also studying and exploiting their consequences. Genes contain the recipes for the proteins that make up cells, and changes to the recipes can affect how these proteins look and work. As the immune system is designed to recognise things out of the ordinary, scientists are finding that the level of genetic chaos within a tumour can affect how the immune system ‘sees’ a tumour.
Using patient samples, Dr Vinod Balachandran, from the Parker Institute in the US, has found that some alterations to proteins caused by genetic changes in pancreatic cancer are better at alerting the immune system than others. Assessing the ‘quality’ of these molecules, he said, could help guide the development of new immunotherapies to better equip the immune system to attack the cancer.
2017 Cancer Research UK Research Prizes
- Future Leaders: Dr Gerhardt Attard, Dr Simon Leedham, Dr Santiago Zelenay
- Jane Wardle Prize: Prof Greg Rubin
- Translational Cancer Research Prize: Tumour heterogeneity team
Find out more here.
While other presenters on pancreatic cancer discussed different opportunities and challenges for this disease, they all shared a sense of urgency.
“Around 90% of patients will die within a year, and the average survival is just 6 months,” said Professor Andrew Biankin, a Cancer Research UK-funded pancreatic cancer expert from the University of Glasgow. “These are things I’d like to see change.”
Balachandran and others are also studying the immune cells within and around patients’ tumours to try and find out why some can attack cancer cells while others fail. Through his work at the University of Southampton, Professor Gareth Thomas has found one obstacle to an effective attack: cancer-associated fibroblasts. These are healthy cells that become coerced into helping the tumour, and through his work in the lab Thomas has discovered that these cells can form a protective barrier that blocks immune cells.
Clearing hurdles
The diversity of research presented at NCRI serves as a reminder that there is no single solution to cancer, and that to make progress in beating the disease we need to attack it from all angles – and in smarter ways. That’s why collaboration is so important to make progress, a point that echoed throughout this year’s conference.
But as always, the research showcased gives plenty of room for hope, as well as inspiration to keep up the hard work. And the more heads that continue to come together, the more pieces of this complex puzzle will begin to slot into place, bringing solutions closer every day.
Justine
from Cancer Research UK – Science blog http://ift.tt/2m0Zvdg
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