News digest – Pregnancy reprograms breast cells, reducing organ transplant rejection, new uses for malaria drug, and white blood cell-inspired glass robots

Malaria drug used to treat glioblastoma 

One of the most aggressive types of brain cancer could be treated with an already approved malaria drug. Lumefantrine has been proposed in combination with the current  care/treatments – to treat patients with glioblastoma.  This type of brain cancer has a poor survival rate, and it is hoped that lumefantrine will boost the effectiveness of existing treatments. Read more on this at New Atlas 

Scientists unlock potential to reduce transplant rejection 

A new study in the Journal of Clinical Investigation has reported a key molecule that could be responsible for the slow decay of transplanted tissue. The molecules, called HLA antigens, almost always differ between patients (except in the case of identical twins) and are known targets for antibodies which can cause the body to launch an immune response against the foreign tissue. By inhibiting the molecule, scientists believe they could reduce the likelihood of organ rejection in transplant patients. Yale News has the full story.    

Microscopic robots rush against blood to target cancer cells 

The Evening Standard reports on an experimental trial using microscopic glass robots to detect cancerous tissue and deliver chemotherapy drugs to target cancer cells. The tiny spherical devices can move against the flow of blood, allowing them to reach “hard-to-access regions” inside the human body. Tests using mouse blood and artificial blood vessels showed that the robots to effectively target cancer cells in the presence of healthy cells. Read more at New Scientist. 

Younger pregnancy linked to lower risk of breast cancer 

Scientists have found a connection between a lower  risk of breast cancer and the reduced expression of a potent cancer gene in pregnant mice. According to research, breast cells are able to protect themselves from cancer after pregnancy by tucking a potent cancer gene (known as cMYC) away where it cannot cause harm. Breast cells are also able to suspend potential cancer cells in a ‘pre-senescence’ state between living, dying and developing into cancer. More on this at PR Newswire. 

And finally… 

An investigation into the early development of high-grade serous ovarian cancer has found the cells of the oviduct in mice (similar to the fallopian tubes in humans) to be more prone to developing tumours than cells in the outer layers of the ovaries.  Further study into the development and progress of this type of cancer in organoid models is hoped to provide a better understanding of how the disease develops. Read more at News Medical. 

Scarlett Sangster is a writer for PA Media Group

from Cancer Research UK – Science blog https://ift.tt/2M98N1f

Malaria drug used to treat glioblastoma 

One of the most aggressive types of brain cancer could be treated with an already approved malaria drug. Lumefantrine has been proposed in combination with the current  care/treatments – to treat patients with glioblastoma.  This type of brain cancer has a poor survival rate, and it is hoped that lumefantrine will boost the effectiveness of existing treatments. Read more on this at New Atlas 

Scientists unlock potential to reduce transplant rejection 

A new study in the Journal of Clinical Investigation has reported a key molecule that could be responsible for the slow decay of transplanted tissue. The molecules, called HLA antigens, almost always differ between patients (except in the case of identical twins) and are known targets for antibodies which can cause the body to launch an immune response against the foreign tissue. By inhibiting the molecule, scientists believe they could reduce the likelihood of organ rejection in transplant patients. Yale News has the full story.    

Microscopic robots rush against blood to target cancer cells 

The Evening Standard reports on an experimental trial using microscopic glass robots to detect cancerous tissue and deliver chemotherapy drugs to target cancer cells. The tiny spherical devices can move against the flow of blood, allowing them to reach “hard-to-access regions” inside the human body. Tests using mouse blood and artificial blood vessels showed that the robots to effectively target cancer cells in the presence of healthy cells. Read more at New Scientist. 

Younger pregnancy linked to lower risk of breast cancer 

Scientists have found a connection between a lower  risk of breast cancer and the reduced expression of a potent cancer gene in pregnant mice. According to research, breast cells are able to protect themselves from cancer after pregnancy by tucking a potent cancer gene (known as cMYC) away where it cannot cause harm. Breast cells are also able to suspend potential cancer cells in a ‘pre-senescence’ state between living, dying and developing into cancer. More on this at PR Newswire. 

And finally… 

An investigation into the early development of high-grade serous ovarian cancer has found the cells of the oviduct in mice (similar to the fallopian tubes in humans) to be more prone to developing tumours than cells in the outer layers of the ovaries.  Further study into the development and progress of this type of cancer in organoid models is hoped to provide a better understanding of how the disease develops. Read more at News Medical. 

Scarlett Sangster is a writer for PA Media Group

from Cancer Research UK – Science blog https://ift.tt/2M98N1f

On Mars, mud flows like lava

We know that Mars used to be volcanically active in the past. The planet is dotted with enormous now-dormant volcanoes, and the remains of old lava flows can still be seen today. Now, it seems, some of those lava flows weren’t composed of lava at all, but rather mud, according to researchers in Europe. The finding is evidence for what are called sedimentary volcanism, where liquid mud – water-rich sediments – ruptured from Mars’ subsurface, flowing like lava before refreezing. These features have often been seen on Earth, in association with smaller conical hills that resemble mud volcanoes.

The intriguing peer-reviewed results were published in the journal Nature Geoscience on May 20, 2020.

A possible mud volcano on Mars, just one of thousands. Ancient flows from such features and other volcanic spots had previously been assumed to be lava, but a new study suggests that at least in some cases, it was mud instead. That would mean these landforms really are mud volcanoes, not smaller magmatic volcanoes. Image via NASA/ JPL-Caltech/ University of Arizona/ DLR.

From the paper:

Large outflow channels on ancient terrains of Mars have been interpreted as the products of catastrophic flood events. The rapid burial of water-rich sediments after such flooding could have led to sedimentary volcanism, in which mixtures of sediment and water (mud) erupt to the surface.

Tens of thousands of volcano-like landforms populate the northern lowlands … on Mars. However, it is difficult to determine whether the edifices are related to igneous or mud extrusions …

Here we investigate the mechanisms of mud propagation on Mars using experiments performed inside a low-pressure chamber at cold temperatures. We found that low viscosity mud under Martian conditions propagates differently from that on Earth, because of a rapid freezing and the formation of an icy crust. Instead, the experimental mud flows propagate like terrestrial pahoehoe lava flows, with liquid mud spilling from ruptures in the frozen crust, and then refreezing to form a new flow lobe.

We suggest that mud volcanism can explain the formation of some lava-like flow morphologies on Mars, and that similar processes may apply to cryovolcanic extrusions on icy bodies in the solar system.

The low-pressure vacuum chamber used in the experiments. Image via CAS/ Petr Brož/ CC BY-SA 4.0/ DLR.

An example of mud frozen in simulated Mars conditions. The mud froze on the outside but remained liquid on the inside, and formed cavities and shapes similar to lava on Earth. Image via Brož et al./ Nature Geoscience/ CNRS.

The new study was led by researchers from the Institute of Geophysics at the Czech Academy of Sciences (CAS). It involved Lancaster University, the Open University and the Rutherford Appleton Laboratory in the U.K., CNRS in France, DLR and Münster University in Germany, and CEED in Norway.

Ernst Hauber of the DLR Institute of Planetary Research in Berlin-Adlershof said in a statement:

We have long been aware that in the early history of Mars, several billion years ago, large amounts of water were released over a short period of time, eroding very large valleys in the landscape, which have long since dried up. Extensively eroded masses of fragmented rock were transported through these outflow channels and into the northern lowlands of the planet, where they were quickly deposited. Later, these rocky masses were covered by younger sediments and volcanic rocks.

An active mud volcano in Azerbaijan. Image via CAS/ Petr Brož/ CC BY-SA 4.0/ DLR.

Many of the mud flows are found in locations where massive channels were carved by water a few billion years ago. These floods were huge, comparable to the largest floods known on Earth. Water would then seep back into the subsurface, where it could then re-emerge as mud.

How did the researchers determine that some of the lava flows were not really lava, but mud? Lionel Wilson, Emeritus Professor of Earth and Planetary Sciences at Lancaster University, explained:

We performed experiments in a vacuum chamber to simulate the release of mud on Mars. This is of interest because we see many flow-like features on Mars in spacecraft images, but they have not yet been visited by any of the roving vehicles on the surface and there is some ambiguity about whether they are flows of lava or mud.

What they found was quite interesting. Flowing mud on Mars didn’t behave at all like flowing mud on Earth, due to the very thin atmosphere and cold temperatures. The vacuum chamber re-created current Martian conditions. The flowing mud on Mars would freeze quickly and form an icy crust. In the vacuum chamber, the mud flows formed shapes similar to pahoehoe lava, which is common in Hawaii and Iceland. After the mud spilled out of ruptures in the ground, it refroze and formed smooth, undulating surfaces. The outer surface of the mud would freeze on contact with the air, while the inner core remained liquid. This liquid can break the frozen crust to form a new flow lobe that then refreezes.

More conical hills thought to be mud volcanoes, in Coprates Chasma on Mars. Image via Petr Brož/ Mars Reconnaissance Orbiter/ NASA/ JPL/ University of Arizona/ The Conversation.

Rock slab called Old Soaker, found by the Curiosity rover in Gale Crater on Mars, which is covered with what are thought to be mud cracks from when a layer of mud dried out about 3 billion years ago. Image via NASA/ JPL-Caltech/ MSSS.

In another test where the atmospheric pressure was the same as Earth’s, the mud did not form those shapes, even though it was just as cold in the vacuum chamber. Petr Brož, lead author of the new study, said:

Under the low atmospheric pressure of Mars, the mud flows behave in much the same way as pahoehoe, or ‘ropy’, lava, which is familiar from large volcanoes on Hawaii and Iceland. Our experiments show that even a process as apparently simple as the flow of mud – something that many of us have experienced for ourselves since we were children – would be very different on Mars.

Hauber added:

However, the impact of this familiar effect on mud has never been investigated in an experiment before. Once again, it turns out that different physical conditions must always be taken into account when looking at apparently simple surface features on other planets. We now know that we need to consider both mud and lava when analyzing certain flow phenomena.

There are tens of thousands of small conical hills in the northern highlands of Mars that may be mud volcanoes. It isn’t clear whether any of them may still be pumping out mud today, but the findings overall show that mud and wet sediments were common on the planet, at least in the past. In Gale Crater, the Curiosity rover has also found cracked, dried rock slabs that look exactly like dried out mud from the bottom of the lake that used to exist there.

Petr Brož of the Czech Academy of Sciences, lead author of the new study. Image via CAS.

Mars isn’t the only place where this kind of sedimentary volcanism is thought to occur. There is also evidence for a similar process on the dwarf planet Ceres, which may have once had a muddy ocean beneath its outer icy crust. According to Brož:

We suggest that mud volcanism can explain the formation of some lava-like flow morphologies on Mars, and that similar processes may apply to eruptions of mud on icy bodies in the outer solar system, like on Ceres.

Last year it was reported that Ceres likely had subsurface salty muddy meltwater reservoirs that lasted millions of years. The bright spots on Ceres’ surface are now thought to be salt deposits left over from when cryovolcanoes – ice volcanoes – erupted, with the water quickly sublimating away due to the almost complete lack of an atmosphere. Similar features thought to be cryovolcanoes were also discovered on Pluto by the New Horizons spacecraft, and on Saturn’s moon Titan by Cassini. If the flows and conical hills on Mars are really also related to Martian mud, then that would show such processes are common in our solar system (including Earth of course), and could potentially provide valuable clues as to how life originated and evolved on our own planet.

Bottom line: Some features on Mars that were thought to be lava flows may actually be mud flows, according to a new study.

Source: Experimental evidence for lava-like mud flows under Martian surface conditions

Via Lancaster University

Via DLR

from EarthSky https://ift.tt/2AiT7G0

We know that Mars used to be volcanically active in the past. The planet is dotted with enormous now-dormant volcanoes, and the remains of old lava flows can still be seen today. Now, it seems, some of those lava flows weren’t composed of lava at all, but rather mud, according to researchers in Europe. The finding is evidence for what are called sedimentary volcanism, where liquid mud – water-rich sediments – ruptured from Mars’ subsurface, flowing like lava before refreezing. These features have often been seen on Earth, in association with smaller conical hills that resemble mud volcanoes.

The intriguing peer-reviewed results were published in the journal Nature Geoscience on May 20, 2020.

A possible mud volcano on Mars, just one of thousands. Ancient flows from such features and other volcanic spots had previously been assumed to be lava, but a new study suggests that at least in some cases, it was mud instead. That would mean these landforms really are mud volcanoes, not smaller magmatic volcanoes. Image via NASA/ JPL-Caltech/ University of Arizona/ DLR.

From the paper:

Large outflow channels on ancient terrains of Mars have been interpreted as the products of catastrophic flood events. The rapid burial of water-rich sediments after such flooding could have led to sedimentary volcanism, in which mixtures of sediment and water (mud) erupt to the surface.

Tens of thousands of volcano-like landforms populate the northern lowlands … on Mars. However, it is difficult to determine whether the edifices are related to igneous or mud extrusions …

Here we investigate the mechanisms of mud propagation on Mars using experiments performed inside a low-pressure chamber at cold temperatures. We found that low viscosity mud under Martian conditions propagates differently from that on Earth, because of a rapid freezing and the formation of an icy crust. Instead, the experimental mud flows propagate like terrestrial pahoehoe lava flows, with liquid mud spilling from ruptures in the frozen crust, and then refreezing to form a new flow lobe.

We suggest that mud volcanism can explain the formation of some lava-like flow morphologies on Mars, and that similar processes may apply to cryovolcanic extrusions on icy bodies in the solar system.

The low-pressure vacuum chamber used in the experiments. Image via CAS/ Petr Brož/ CC BY-SA 4.0/ DLR.

An example of mud frozen in simulated Mars conditions. The mud froze on the outside but remained liquid on the inside, and formed cavities and shapes similar to lava on Earth. Image via Brož et al./ Nature Geoscience/ CNRS.

The new study was led by researchers from the Institute of Geophysics at the Czech Academy of Sciences (CAS). It involved Lancaster University, the Open University and the Rutherford Appleton Laboratory in the U.K., CNRS in France, DLR and Münster University in Germany, and CEED in Norway.

Ernst Hauber of the DLR Institute of Planetary Research in Berlin-Adlershof said in a statement:

We have long been aware that in the early history of Mars, several billion years ago, large amounts of water were released over a short period of time, eroding very large valleys in the landscape, which have long since dried up. Extensively eroded masses of fragmented rock were transported through these outflow channels and into the northern lowlands of the planet, where they were quickly deposited. Later, these rocky masses were covered by younger sediments and volcanic rocks.

An active mud volcano in Azerbaijan. Image via CAS/ Petr Brož/ CC BY-SA 4.0/ DLR.

Many of the mud flows are found in locations where massive channels were carved by water a few billion years ago. These floods were huge, comparable to the largest floods known on Earth. Water would then seep back into the subsurface, where it could then re-emerge as mud.

How did the researchers determine that some of the lava flows were not really lava, but mud? Lionel Wilson, Emeritus Professor of Earth and Planetary Sciences at Lancaster University, explained:

We performed experiments in a vacuum chamber to simulate the release of mud on Mars. This is of interest because we see many flow-like features on Mars in spacecraft images, but they have not yet been visited by any of the roving vehicles on the surface and there is some ambiguity about whether they are flows of lava or mud.

What they found was quite interesting. Flowing mud on Mars didn’t behave at all like flowing mud on Earth, due to the very thin atmosphere and cold temperatures. The vacuum chamber re-created current Martian conditions. The flowing mud on Mars would freeze quickly and form an icy crust. In the vacuum chamber, the mud flows formed shapes similar to pahoehoe lava, which is common in Hawaii and Iceland. After the mud spilled out of ruptures in the ground, it refroze and formed smooth, undulating surfaces. The outer surface of the mud would freeze on contact with the air, while the inner core remained liquid. This liquid can break the frozen crust to form a new flow lobe that then refreezes.

More conical hills thought to be mud volcanoes, in Coprates Chasma on Mars. Image via Petr Brož/ Mars Reconnaissance Orbiter/ NASA/ JPL/ University of Arizona/ The Conversation.

Rock slab called Old Soaker, found by the Curiosity rover in Gale Crater on Mars, which is covered with what are thought to be mud cracks from when a layer of mud dried out about 3 billion years ago. Image via NASA/ JPL-Caltech/ MSSS.

In another test where the atmospheric pressure was the same as Earth’s, the mud did not form those shapes, even though it was just as cold in the vacuum chamber. Petr Brož, lead author of the new study, said:

Under the low atmospheric pressure of Mars, the mud flows behave in much the same way as pahoehoe, or ‘ropy’, lava, which is familiar from large volcanoes on Hawaii and Iceland. Our experiments show that even a process as apparently simple as the flow of mud – something that many of us have experienced for ourselves since we were children – would be very different on Mars.

Hauber added:

However, the impact of this familiar effect on mud has never been investigated in an experiment before. Once again, it turns out that different physical conditions must always be taken into account when looking at apparently simple surface features on other planets. We now know that we need to consider both mud and lava when analyzing certain flow phenomena.

There are tens of thousands of small conical hills in the northern highlands of Mars that may be mud volcanoes. It isn’t clear whether any of them may still be pumping out mud today, but the findings overall show that mud and wet sediments were common on the planet, at least in the past. In Gale Crater, the Curiosity rover has also found cracked, dried rock slabs that look exactly like dried out mud from the bottom of the lake that used to exist there.

Petr Brož of the Czech Academy of Sciences, lead author of the new study. Image via CAS.

Mars isn’t the only place where this kind of sedimentary volcanism is thought to occur. There is also evidence for a similar process on the dwarf planet Ceres, which may have once had a muddy ocean beneath its outer icy crust. According to Brož:

We suggest that mud volcanism can explain the formation of some lava-like flow morphologies on Mars, and that similar processes may apply to eruptions of mud on icy bodies in the outer solar system, like on Ceres.

Last year it was reported that Ceres likely had subsurface salty muddy meltwater reservoirs that lasted millions of years. The bright spots on Ceres’ surface are now thought to be salt deposits left over from when cryovolcanoes – ice volcanoes – erupted, with the water quickly sublimating away due to the almost complete lack of an atmosphere. Similar features thought to be cryovolcanoes were also discovered on Pluto by the New Horizons spacecraft, and on Saturn’s moon Titan by Cassini. If the flows and conical hills on Mars are really also related to Martian mud, then that would show such processes are common in our solar system (including Earth of course), and could potentially provide valuable clues as to how life originated and evolved on our own planet.

Bottom line: Some features on Mars that were thought to be lava flows may actually be mud flows, according to a new study.

Source: Experimental evidence for lava-like mud flows under Martian surface conditions

Via Lancaster University

Via DLR

from EarthSky https://ift.tt/2AiT7G0

Coronavirus reports – Part 4: “I know I’m in a queue, but things feel uncertain”

We caught up with people living with cancer across the country, to find out how the coronavirus pandemic has been affecting them and their families. 

Paul: “I understand the reasons for the delay and I know I’m in a queue, but things feel uncertain” 

Paul from Enfield, London was diagnosed with both lung and prostate cancer in 2019.  

“I was diagnosed with two cancers at the same time, which I know is very unusual.” Paul, who says he always been pretty active, retired in July 2019 at the age of 66. That’s when investigations for prostate cancer began.  

During a CT scan, doctors picked up something on Paul’s lung, which turn out to be cancer.  

Paul was diagnosed with both lung and prostate cancer in 2019.

“I was not scared when I thought it was just prostate cancer. When they said it was lung cancer too, I had a sudden realisation of being vulnerable. I was a pretty fit bloke. I was very active and think of myself as a young man!” 

Paul had surgery for lung cancer in February and his prognosis is good. “I didn’t need to have any chemotherapy or radiotherapy, I’ll be monitored now for 5 years.” 

But his radiotherapy for prostate cancer has been put on hold due to COVID-19.  

“I am assured the cancer is curable by hormone treatment and radiotherapy, but the radiotherapy was postponed until September.”  

Paul said he was happy with the decision at the time, and he is still having injections to inhibit testosterone. But the delays are starting to worry him.  

“I understand the reasons for the delay and I know I’m in a queue, but things feel uncertain. My CT scan for both cancers has been put on hold too. So, I hope there aren’t any problems because of that delay.” 

“I am currently shielding but I did sign up to the Walk All Over Cancer fundraiser during March  – it was a good challenge and it really helped me.” 

Saima: “It’s very worrying to hear of anything that might hold up new treatments” 

Saima was diagnosed with stage  4 lung cancer in 2018, when she was 29. For her, the coronavirus outbreak moved up her treatment.  

“It has been crazy – as soon as the virus became a pandemic, I had lots of treatment lined up.” Saima’s having ongoing chemotherapy and as the cancer has spread to her brain, she also had a targeted radiotherapy called CyberKnife. “I had four days’ worth of treatment in the first week of lockdown. 

Saima had the CyberKnife treatment at St Barts Hospital in London, “I went to Barts  and they took my temperature on the way in. It was so efficient. There was no one there for anything routine, only compulsory appointments”  

Since then, she’s been told not to leave the house.   

“I am lucky to be in Kent. We have a garden and outdoor space”. Despite this, Saima says mental health is going to be a big issue – “there’s so much trauma happening anyway with cancer and it’s going to have such an impact. It’s too much to think about with COVID-19 risks too”.   

“I’ve spoken to others in the BAME community and I do think there’s still a way to go when it comes to cancer taboos, and educating people about how they can stay safe.” 

A big concern for Saima is also the state of clinical trials, many of which have had to pause recruitment because of the pandemic. “I am stage 4 – to hear of trials being stopped, that is alarming. I need those to keep running to give me hope.  

“It’s very worrying to hear of anything which might hold up any  new cancer treatments being developed.” 

Sophie: “I find it so concerning that this was not a decision I was included in” 

Sophie was diagnosed with breast cancer in 2016. She had surgery and treatment, but the cancer came back in 2018. 

“It had spread to my liver, lungs and spine. I had chemotherapy which worked well but earlier this year, I had a scan that showed it had progressed to the brain.” Sophie’s treatment was changed because of the COVID-19 pandemic. While she’s been switched to a safer option, Sophie says the treatment has a lower chance of working. 

“I was told I could not have the chemo for two reasons – first because they

Sophie was diagnosed with breast cancer in 2016.

said I couldn’t have an IV as there was a risk of getting the virus, and secondly because they wanted to cut down on staff for the COVID wards.” Sophie said she would preferred the treatment with the better prospects, even with the risks.  

“My disease is very progressed and I have been given weeks or months if the chemo doesn’t work. I find it so concerning that this treatment change wasn’t a decision I was included in. Lots of people might die as a result of the impact of COVID-19 on people’s care.”  

“My husband and I have just had a baby through surrogacy too – I have so much to look forward to.” 

Mary: “I was so stressed I wouldn’t get the treatment I needed” 

Mary describes her diagnosis as a “bolt out of the blue”. She was sent for some tests in December 2019, after experiencing heavy periods for the last couple of years. In January, she was set to the Princess of Wales hospital for an appointment, where the doctor told her she had womb cancer.  

“My head was spinning after I heard the word cancer. It was a complete shock.” Mary had been at work that morning and had left her car at the office as she was expecting to be dropped back there after the appointment. “I have not been back.”  

Despite the initial shock, Mary says the NHS have been brilliant. “I had a radical hysterectomy on the 4th February, which was luckily before any talk of lockdown – I am thankful that happened when it did.”  

The operation went well and Mary was in hospital for 3 nights. A few weeks

Mary was diagnosed with womb cancer in 2019.

later, she was told she would need radiotherapy because she had a satellite tumour on her cervix, which she requested to at Velindre Cancer Centre in Cardiff to be nearer family.  

“I went for my planning CT scan the morning that lockdown was announced. I was so stressed that I wouldn’t be able to get the treatment that I needed.” Mary says despite her concerns, the team at the Velindre have been marvellous. “They said they were going to keep going and I started my treatment on the 7th April.” 

A big concern for Mary was travel, but the staff put her at ease. The routine was for her husband Gwyn to drive her in, and they would park the car, ring reception and wait until the team were ready before she went in. She had her temperature taken every day and no visitors were allowed. “It was so professional, and the drive in was much quicker because the roads were so quiet – in fact I felt guilty going in one day as I heard on the radio about people having treatment disrupted and that was not my experience.”   

After four weeks of external beam radiotherapy and one week of brachytherapy, during which Mary says, “all dignity went out the window”, her treatment finished on the 14th May. “The staff were amazing throughout.”  

Mary’s experiencing side effects from the radiotherapy, but overall she’s feeling positive. “I am now looking forward with the support of my family and friends – my eldest was doing her mock A-levels at the time of my diagnosis and is hoping to go to university in September.”  

She’s waiting for follow-up appointments now – which might end up being a phone call. “I’m waiting for a letter about that and a CT scan too.” 

Katie 

Read more coronavirus reports:

• “I should have known when they came back in PPE”
• “We’re ahead when it comes to isolation”
• “I’m taking things week by week”

Thanks to Paul, Saima, Sophie and Mary for sharing their experiences with our Media Volunteer Liaison team. 

If you would like to share your story with us, please visit our website. And you can tell us how COVID-19 is impacting your life with cancer through our survey. 

If you have questions about cancer, you can talk to our nurses Monday to Friday, 9-5pm, on freephone 0808 800 4040. 

from Cancer Research UK – Science blog https://ift.tt/3ddphkR

We caught up with people living with cancer across the country, to find out how the coronavirus pandemic has been affecting them and their families. 

Paul: “I understand the reasons for the delay and I know I’m in a queue, but things feel uncertain” 

Paul from Enfield, London was diagnosed with both lung and prostate cancer in 2019.  

“I was diagnosed with two cancers at the same time, which I know is very unusual.” Paul, who says he always been pretty active, retired in July 2019 at the age of 66. That’s when investigations for prostate cancer began.  

During a CT scan, doctors picked up something on Paul’s lung, which turn out to be cancer.  

Paul was diagnosed with both lung and prostate cancer in 2019.

“I was not scared when I thought it was just prostate cancer. When they said it was lung cancer too, I had a sudden realisation of being vulnerable. I was a pretty fit bloke. I was very active and think of myself as a young man!” 

Paul had surgery for lung cancer in February and his prognosis is good. “I didn’t need to have any chemotherapy or radiotherapy, I’ll be monitored now for 5 years.” 

But his radiotherapy for prostate cancer has been put on hold due to COVID-19.  

“I am assured the cancer is curable by hormone treatment and radiotherapy, but the radiotherapy was postponed until September.”  

Paul said he was happy with the decision at the time, and he is still having injections to inhibit testosterone. But the delays are starting to worry him.  

“I understand the reasons for the delay and I know I’m in a queue, but things feel uncertain. My CT scan for both cancers has been put on hold too. So, I hope there aren’t any problems because of that delay.” 

“I am currently shielding but I did sign up to the Walk All Over Cancer fundraiser during March  – it was a good challenge and it really helped me.” 

Saima: “It’s very worrying to hear of anything that might hold up new treatments” 

Saima was diagnosed with stage  4 lung cancer in 2018, when she was 29. For her, the coronavirus outbreak moved up her treatment.  

“It has been crazy – as soon as the virus became a pandemic, I had lots of treatment lined up.” Saima’s having ongoing chemotherapy and as the cancer has spread to her brain, she also had a targeted radiotherapy called CyberKnife. “I had four days’ worth of treatment in the first week of lockdown. 

Saima had the CyberKnife treatment at St Barts Hospital in London, “I went to Barts  and they took my temperature on the way in. It was so efficient. There was no one there for anything routine, only compulsory appointments”  

Since then, she’s been told not to leave the house.   

“I am lucky to be in Kent. We have a garden and outdoor space”. Despite this, Saima says mental health is going to be a big issue – “there’s so much trauma happening anyway with cancer and it’s going to have such an impact. It’s too much to think about with COVID-19 risks too”.   

“I’ve spoken to others in the BAME community and I do think there’s still a way to go when it comes to cancer taboos, and educating people about how they can stay safe.” 

A big concern for Saima is also the state of clinical trials, many of which have had to pause recruitment because of the pandemic. “I am stage 4 – to hear of trials being stopped, that is alarming. I need those to keep running to give me hope.  

“It’s very worrying to hear of anything which might hold up any  new cancer treatments being developed.” 

Sophie: “I find it so concerning that this was not a decision I was included in” 

Sophie was diagnosed with breast cancer in 2016. She had surgery and treatment, but the cancer came back in 2018. 

“It had spread to my liver, lungs and spine. I had chemotherapy which worked well but earlier this year, I had a scan that showed it had progressed to the brain.” Sophie’s treatment was changed because of the COVID-19 pandemic. While she’s been switched to a safer option, Sophie says the treatment has a lower chance of working. 

“I was told I could not have the chemo for two reasons – first because they

Sophie was diagnosed with breast cancer in 2016.

said I couldn’t have an IV as there was a risk of getting the virus, and secondly because they wanted to cut down on staff for the COVID wards.” Sophie said she would preferred the treatment with the better prospects, even with the risks.  

“My disease is very progressed and I have been given weeks or months if the chemo doesn’t work. I find it so concerning that this treatment change wasn’t a decision I was included in. Lots of people might die as a result of the impact of COVID-19 on people’s care.”  

“My husband and I have just had a baby through surrogacy too – I have so much to look forward to.” 

Mary: “I was so stressed I wouldn’t get the treatment I needed” 

Mary describes her diagnosis as a “bolt out of the blue”. She was sent for some tests in December 2019, after experiencing heavy periods for the last couple of years. In January, she was set to the Princess of Wales hospital for an appointment, where the doctor told her she had womb cancer.  

“My head was spinning after I heard the word cancer. It was a complete shock.” Mary had been at work that morning and had left her car at the office as she was expecting to be dropped back there after the appointment. “I have not been back.”  

Despite the initial shock, Mary says the NHS have been brilliant. “I had a radical hysterectomy on the 4th February, which was luckily before any talk of lockdown – I am thankful that happened when it did.”  

The operation went well and Mary was in hospital for 3 nights. A few weeks

Mary was diagnosed with womb cancer in 2019.

later, she was told she would need radiotherapy because she had a satellite tumour on her cervix, which she requested to at Velindre Cancer Centre in Cardiff to be nearer family.  

“I went for my planning CT scan the morning that lockdown was announced. I was so stressed that I wouldn’t be able to get the treatment that I needed.” Mary says despite her concerns, the team at the Velindre have been marvellous. “They said they were going to keep going and I started my treatment on the 7th April.” 

A big concern for Mary was travel, but the staff put her at ease. The routine was for her husband Gwyn to drive her in, and they would park the car, ring reception and wait until the team were ready before she went in. She had her temperature taken every day and no visitors were allowed. “It was so professional, and the drive in was much quicker because the roads were so quiet – in fact I felt guilty going in one day as I heard on the radio about people having treatment disrupted and that was not my experience.”   

After four weeks of external beam radiotherapy and one week of brachytherapy, during which Mary says, “all dignity went out the window”, her treatment finished on the 14th May. “The staff were amazing throughout.”  

Mary’s experiencing side effects from the radiotherapy, but overall she’s feeling positive. “I am now looking forward with the support of my family and friends – my eldest was doing her mock A-levels at the time of my diagnosis and is hoping to go to university in September.”  

She’s waiting for follow-up appointments now – which might end up being a phone call. “I’m waiting for a letter about that and a CT scan too.” 

Katie 

Read more coronavirus reports:

• “I should have known when they came back in PPE”
• “We’re ahead when it comes to isolation”
• “I’m taking things week by week”

Thanks to Paul, Saima, Sophie and Mary for sharing their experiences with our Media Volunteer Liaison team. 

If you would like to share your story with us, please visit our website. And you can tell us how COVID-19 is impacting your life with cancer through our survey. 

If you have questions about cancer, you can talk to our nurses Monday to Friday, 9-5pm, on freephone 0808 800 4040. 

from Cancer Research UK – Science blog https://ift.tt/3ddphkR

Curiosity rover finds evidence for ancient ice-covered lake on Mars

Artist’s concept of Gale Crater when it was filled by a lake a few billion years ago. The Curiosity rover has now previous evidence for the lake or series of lakes over time, and now a new study suggests that the lake could have been covered by ice during colder climate periods. Image via NASA/ JPL-Caltech/ ESA/ DLR/ FU Berlin/ MSSS.

A few billion years ago, Gale Crater on Mars held a lake or series of lakes. There was even a river that once fed into this lake. That’s the conclusion of scientists working with data from NASA’s Curiosity rover on Mars, which landed inside Gale Crater in August, 2012, and has been exploring the region ever since. Now, a new study of Curiosity data by NASA scientists has added more pieces to the puzzle of what conditions on ancient Mars were like.

NASA announced the study on May 19, 2020. The peer-reviewed paper detailing these findings was published on January 27 in the journal Nature.

The results come from a comprehensive analysis of data from a multi-year experiment onboard the rover, in a chemistry lab called Sample Analysis at Mars (SAM). SAM has been analyzing the chemistry and minerals in rock samples, including organic compounds – the building blocks of life – to determine the habitability of this part of Mars early in its history. This testing has previously confirmed abundant liquid water in the past, as well as a variety of organic molecules preserved in Martian rocks.

Diagram of the proposed carbon cycle on Mars. With little water and no abundant surface life on the planet, the cycle is quite different from the one on Earth. Image via Lance Hayashida/ Caltech/ NASA.

The SAM instrument at Goddard Space Flight Center, before it was placed on Curiosity for the trip to Mars. Image via NASA/ GSFC.

The latest analysis has found evidence for a previous ice-covered lake in Gale Crater, thought to have possibly existed in a colder period between two warmer periods of time. Heather Franz, a geochemist at Goddard Space Flight Center who led the new study, said in a statement:

At some point, Mars’ surface environment must have experienced a transition from being warm and humid to being cold and dry, as it is now, but exactly when and how that occurred is still a mystery.

The evidence supports the idea that Mars’ climate alternated between warmer and colder before finally becoming permanently cold and dry as we see it today. Changes in the axis tilt of the planet and volcanic activity could have played a major part in that instability. Indeed, chemical and mineralogical changes in martian rocks also show this, with some rock layers being formed in warmer conditions, but others in colder climates.

The Quisquiro salt flat in Altiplano, South America. Scientists think this may be similar to the lake(s) that once existed in Gale Crater on Mars. Image via Maksym Bocharov/ NASA.

So how did Franz and her team find the evidence for an ice-covered lake?

Over five years, Curiosity collected 13 rock and dust samples. From these, the gases carbon dioxide and oxygen were extracted inside SAM. Each sample was heated to 1,650 degrees Fahrenheit (900 degrees Celsius), in order to liberate the trapped gases. The temperatures of the SAM oven at the time provided clues as to the kinds of minerals the gases were coming from. This provided insight into Mars’ carbon cycle, where the gas is exchanged between Mars’ subsurface, surface rocks, polar caps, water and atmosphere. While Mars still has a carbon cycle today, it is a lot different than Earth’s, since it has little water and no abundant surface life. As Paul Mahaffy, principal investigator on SAM explained:

Nevertheless, the carbon cycling is still happening and is still important because it’s not only helping reveal information about Mars’ ancient climate. It’s also showing us that Mars is a dynamic planet that’s circulating elements that are the buildings blocks of life as we know it.

Mars doesn’t seem to have a lot of carbonates left – minerals composed of carbon and oxygen – which would be evidence for Mars once having a much thicker atmosphere, probably mostly carbon dioxide like today. Such an atmosphere would be needed to help explain how the planet could have once had long-lasting lakes and rivers. But, even though the carbonates may be sparse where Curiosity landed, the ones it has found so far have provided valuable clues about the ancient martian climate.

Comparison of a carbonate molecule and an oxalate molecule. Image via James Tralie/ NASA/ Goddard Space Flight Center.

By examining the isotopes of the oxygen and carbon dioxide – versions of each element with different molecular masses – scientists can learn what chemical processes were involved in the formation of the rocks, including whether any biological activity might have been involved, as happens on Earth. The analysis showed that in some of the carbonates, the oxygen isotopes were lighter than those found in the martian atmosphere.

Why is that significant? It suggests the carbonates formed in a cold, likely ice-covered, lake. If the carbonates had formed in a warmer lake, then the isotopes should have actually been slightly heavier than the ones from the air. The researchers say that the ice might have sucked up the heavy oxygen isotopes, leaving behind the lighter ones that would eventually be found in the carbonates.

This is puzzling though, because it might mean the atmosphere was still thinner than thought. But without a thicker, warmer atmosphere, how could there have been lakes, rivers and maybe even a northern hemisphere ocean back then, as other other studies have shown?

The answer may be in the form of minerals called oxalates. Franz and her team suggest that some of the carbon may have been stored in oxalates rather than carbonates. The temperatures at which the carbon dioxide was released from some samples inside SAM was too low for carbonates, but just right for oxalates. The ratios of carbon and oxygen isotopes found also support this hypothesis.

Heather Franz at NASA’s Goddard Space Flight Center, who led the new study. Image via NASA/ Goddard Space Flight Center.

If it could be proven that oxalates were involved, that would be intriguing, since they are the most common mineral produced by plant life on Earth, synthesized by the incomplete oxidation of carbohydrates. That in itself wouldn’t prove life on early Mars, however, since they can also be produced by the interaction of carbon dioxide with surface minerals (inorganic or organic catalysts), water and sunlight. This is a process that “mocks” photosynthesis, called abiotic photosynthesis. It may even have paved the way for actual photosynthesis to be utilized by microbes on Earth.

Additional analysis of these and future SAM samples will be necessary to further figure out what role oxalates played, if any. The upcoming Perseverance rover mission to  Jezero Crater, scheduled to launch this summer, should be able to shed more light on the Curiosity findings. Jezero Crater is similar to Gale Crater, in that it also used to contain a lake, and an ancient delta is still clearly visible where a river once emptied into the lake. Perseverance is designed to specifically look for evidence of ancient microbial life on Mars, so it will be very interesting to see what it finds.

Bottom line: A new study of results from the Curiosity rover provides evidence for an ice-covered lake once existing in Gale Crater on Mars.

from EarthSky https://ift.tt/2BdV0UZ

Artist’s concept of Gale Crater when it was filled by a lake a few billion years ago. The Curiosity rover has now previous evidence for the lake or series of lakes over time, and now a new study suggests that the lake could have been covered by ice during colder climate periods. Image via NASA/ JPL-Caltech/ ESA/ DLR/ FU Berlin/ MSSS.

A few billion years ago, Gale Crater on Mars held a lake or series of lakes. There was even a river that once fed into this lake. That’s the conclusion of scientists working with data from NASA’s Curiosity rover on Mars, which landed inside Gale Crater in August, 2012, and has been exploring the region ever since. Now, a new study of Curiosity data by NASA scientists has added more pieces to the puzzle of what conditions on ancient Mars were like.

NASA announced the study on May 19, 2020. The peer-reviewed paper detailing these findings was published on January 27 in the journal Nature.

The results come from a comprehensive analysis of data from a multi-year experiment onboard the rover, in a chemistry lab called Sample Analysis at Mars (SAM). SAM has been analyzing the chemistry and minerals in rock samples, including organic compounds – the building blocks of life – to determine the habitability of this part of Mars early in its history. This testing has previously confirmed abundant liquid water in the past, as well as a variety of organic molecules preserved in Martian rocks.

Diagram of the proposed carbon cycle on Mars. With little water and no abundant surface life on the planet, the cycle is quite different from the one on Earth. Image via Lance Hayashida/ Caltech/ NASA.

The SAM instrument at Goddard Space Flight Center, before it was placed on Curiosity for the trip to Mars. Image via NASA/ GSFC.

The latest analysis has found evidence for a previous ice-covered lake in Gale Crater, thought to have possibly existed in a colder period between two warmer periods of time. Heather Franz, a geochemist at Goddard Space Flight Center who led the new study, said in a statement:

At some point, Mars’ surface environment must have experienced a transition from being warm and humid to being cold and dry, as it is now, but exactly when and how that occurred is still a mystery.

The evidence supports the idea that Mars’ climate alternated between warmer and colder before finally becoming permanently cold and dry as we see it today. Changes in the axis tilt of the planet and volcanic activity could have played a major part in that instability. Indeed, chemical and mineralogical changes in martian rocks also show this, with some rock layers being formed in warmer conditions, but others in colder climates.

The Quisquiro salt flat in Altiplano, South America. Scientists think this may be similar to the lake(s) that once existed in Gale Crater on Mars. Image via Maksym Bocharov/ NASA.

So how did Franz and her team find the evidence for an ice-covered lake?

Over five years, Curiosity collected 13 rock and dust samples. From these, the gases carbon dioxide and oxygen were extracted inside SAM. Each sample was heated to 1,650 degrees Fahrenheit (900 degrees Celsius), in order to liberate the trapped gases. The temperatures of the SAM oven at the time provided clues as to the kinds of minerals the gases were coming from. This provided insight into Mars’ carbon cycle, where the gas is exchanged between Mars’ subsurface, surface rocks, polar caps, water and atmosphere. While Mars still has a carbon cycle today, it is a lot different than Earth’s, since it has little water and no abundant surface life. As Paul Mahaffy, principal investigator on SAM explained:

Nevertheless, the carbon cycling is still happening and is still important because it’s not only helping reveal information about Mars’ ancient climate. It’s also showing us that Mars is a dynamic planet that’s circulating elements that are the buildings blocks of life as we know it.

Mars doesn’t seem to have a lot of carbonates left – minerals composed of carbon and oxygen – which would be evidence for Mars once having a much thicker atmosphere, probably mostly carbon dioxide like today. Such an atmosphere would be needed to help explain how the planet could have once had long-lasting lakes and rivers. But, even though the carbonates may be sparse where Curiosity landed, the ones it has found so far have provided valuable clues about the ancient martian climate.

Comparison of a carbonate molecule and an oxalate molecule. Image via James Tralie/ NASA/ Goddard Space Flight Center.

By examining the isotopes of the oxygen and carbon dioxide – versions of each element with different molecular masses – scientists can learn what chemical processes were involved in the formation of the rocks, including whether any biological activity might have been involved, as happens on Earth. The analysis showed that in some of the carbonates, the oxygen isotopes were lighter than those found in the martian atmosphere.

Why is that significant? It suggests the carbonates formed in a cold, likely ice-covered, lake. If the carbonates had formed in a warmer lake, then the isotopes should have actually been slightly heavier than the ones from the air. The researchers say that the ice might have sucked up the heavy oxygen isotopes, leaving behind the lighter ones that would eventually be found in the carbonates.

This is puzzling though, because it might mean the atmosphere was still thinner than thought. But without a thicker, warmer atmosphere, how could there have been lakes, rivers and maybe even a northern hemisphere ocean back then, as other other studies have shown?

The answer may be in the form of minerals called oxalates. Franz and her team suggest that some of the carbon may have been stored in oxalates rather than carbonates. The temperatures at which the carbon dioxide was released from some samples inside SAM was too low for carbonates, but just right for oxalates. The ratios of carbon and oxygen isotopes found also support this hypothesis.

Heather Franz at NASA’s Goddard Space Flight Center, who led the new study. Image via NASA/ Goddard Space Flight Center.

If it could be proven that oxalates were involved, that would be intriguing, since they are the most common mineral produced by plant life on Earth, synthesized by the incomplete oxidation of carbohydrates. That in itself wouldn’t prove life on early Mars, however, since they can also be produced by the interaction of carbon dioxide with surface minerals (inorganic or organic catalysts), water and sunlight. This is a process that “mocks” photosynthesis, called abiotic photosynthesis. It may even have paved the way for actual photosynthesis to be utilized by microbes on Earth.

Additional analysis of these and future SAM samples will be necessary to further figure out what role oxalates played, if any. The upcoming Perseverance rover mission to  Jezero Crater, scheduled to launch this summer, should be able to shed more light on the Curiosity findings. Jezero Crater is similar to Gale Crater, in that it also used to contain a lake, and an ancient delta is still clearly visible where a river once emptied into the lake. Perseverance is designed to specifically look for evidence of ancient microbial life on Mars, so it will be very interesting to see what it finds.

Bottom line: A new study of results from the Curiosity rover provides evidence for an ice-covered lake once existing in Gale Crater on Mars.

from EarthSky https://ift.tt/2BdV0UZ

Why these astronomers now doubt there’s a Planet Nine

An artist’s concept of a hypothetical planet with a distant sun. Image via Shutterstock/ The Conversation.

by Samantha Lawler, University of Regina

Planet Nine is a theoretical, undiscovered giant planet in the mysterious far reaches of our solar system.

The presence of Planet Nine has been hypothesized to explain everything from the tilt of the sun’s spin axis to the apparent clustering in the orbits of small, icy asteroids beyond Neptune.

But does Planet Nine actually exist?

Discoveries at the edge of our solar system

The Kuiper Belt is a collection of small, icy bodies that orbit the sun beyond Neptune, at distances larger than 30 AU (one astronomical unit or AU is the distance between the Earth and the sun). These Kuiper Belt objects (KBOs) range in size from large boulders to 1,200 miles (2,000 km) across. KBOs are leftover small bits of planetary material that were never incorporated into planets, similar to the asteroid belt.

After Pluto, the second Kuiper Belt Object — 1992 QB1 — was discovered in 1992 by American astronomers David Jewitt and Jane Luu using the 2.2-m telescope at Mauna Kea in Hawaii. Image via NASA.

The discoveries from the most successful Kuiper Belt survey to date, the Outer Solar System Origins Survey (OSSOS), suggest a sneakier explanation for the orbits we see. Many of these KBOs have been discovered to have very elliptical and tilted orbits, like Pluto.

Mathematical calculations and detailed computer simulations have shown that the orbits we see in the Kuiper Belt can only have been created if Neptune originally formed a few AU closer to the sun, and migrated outward to its present orbit. Neptune’s migration explains the pervasiveness of highly elliptical orbits in the Kuiper Belt, and can explain all the KBO orbits we’ve observed, except for a handful of KBOs on extreme orbits that always stay at least 10 AU beyond Neptune.

Proof of Planet Nine?

These extreme orbits have provided the strongest evidence for Planet Nine. The first few that were discovered were all confined to one quadrant of the solar system. Astronomers expect to observe orbits at all different orientations, unless there is an outside force confining them. Finding several extreme KBOs on orbits pointed in the same direction was a hint that something was going on. Two separate groups of researchers calculated that only a large, very distant planet could keep all the orbits confined to part of the solar system, and the theory of Planet Nine was born.

Planet Nine is theorized to be five to 10 times as massive as Earth, with an orbit ranging between 300-700 AU. There have been several published predictions for its location in the solar system, but none of the search teams have yet discovered it. After more than four years of searching, there is still only indirect evidence in favour of Planet Nine.

The search for KBOs

Searching for KBOs requires careful planning, precise calculations and meticulous followup. I am part of the OSSOS, a collaboration of 40 astronomers from eight countries. We used the Canada-France-Hawaii Telescope over five years to discover and track more than 800 new KBOs, nearly doubling the number of known KBOs with well-measured orbits. The KBOs discovered by OSSOS range in size from a few kilometers to over 100 km, and range in discovery distance from a few AU to over 100 AU, with the majority at 40-42 AU in the main Kuiper Belt.

KBOs do not emit their own light: these small, icy bodies only reflect light from the sun. Thus, the biases against detection at larger distances are extreme: if you move a KBO 10 times farther away, it will become 10,000 times fainter. And because of the laws of physics, KBOs on elliptical orbits will spend most of their time at the most distant parts of their orbits. So, while it is easy to find KBOs on elliptical orbits when they are close to the sun and bright, these KBOs spend most time being much fainter and harder to detect.

This means that the KBOs on elliptical orbits are particularly hard to discover, especially the extreme ones that always stay relatively far from the sun. Only a few of these have been found to date and, with current telescopes, we can only discover them when they are near pericenter — the closest point to the sun in their orbit.

This leads to another observation bias that has historically been ignored by many KBO surveys: KBOs in each part of the solar system can only be discovered at certain times of year. Ground-based telescopes are additionally limited by seasonal weather, with discoveries less likely to happen during when cloudy, rainy or windy conditions are more frequent. Discoveries of KBOs are also much less likely near the plane of the Milky Way galaxy, where countless stars make it difficult to find the faint, icy wanderers in telescopic images.

What makes OSSOS unique is that we are very public about these biases in discoveries. And because we understand our biases so well, we can use computer simulations to reconstruct the true shape of the Kuiper Belt after removing these biases.

Adjusting for biases

OSSOS discovered a handful of new extreme KBOs, half of which are outside the confined region, and are statistically consistent with a uniform distribution. A new study (currently in review) corroborates the non-clustered discoveries of OSSOS. A team of astronomers using data from the Dark Energy Survey (DES) found over 300 new KBOs with no clustering of orbits. So now two independent surveys — both of which carefully tracked and reported their observational biases in discovering independent sets of extreme KBOs — have found no evidence for clustered orbits.

All known KBOs with orbits larger than 250 AU. The orbits of KBOs discovered by OSSOS and DES are in many directions; previous surveys with unknown biases discovered them in the same direction. This image was produced using public data from the Minor Planet Center Database. Image via Samantha Lawler/ The Conversation.

All of the extreme KBOs that had been discovered prior to OSSOS and DES were from surveys that did not fully report their directional biases. So we do not know if all these KBOs were discovered in the same quadrant of the solar system because they are actually confined, or because no surveys searched deep enough in the other quadrants. We performed additional simulations that showed that if observations are made only in one season from one telescope, extreme KBOs will naturally only be discovered in one quadrant of the solar system.

Further testing the Planet Nine theory, we looked in detail at the orbits of all known “extreme” KBOs and found that all but the two highest pericentre KBOs can be explained by known physical effects. These two KBOs are outliers, but our previous detailed computer simulations of the Kuiper Belt, which included gravitational effects from Planet Nine, produced a set of “extreme” KBOs with pericenters smoothly ranging from 40 to over 100 AU.

These simulations predict that there should be many KBOs with pericenters as large as the two outliers, but also many KBOs with smaller pericenters, which should be much easier to detect. Why don’t the orbit discoveries match the predictions? The answer may be that the Planet Nine theory does not hold up to detailed observations.

Our observations with a careful survey have discovered KBOs that are not confined by Planet Nine, and our simulations show that the Kuiper Belt should contain different orbits than we observe if Planet Nine exists. Other theories must be invoked to explain the high-pericentre extreme KBOs, but there is no lack of proposed theories in the scientific literature.

Many beautiful and surprising objects remain to be discovered in the mysterious outer solar system, but I don’t believe that Planet Nine is one of them.

Samantha Lawler, Assistant professor of astronomy, University of Regina

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Astronomers think there might not be a Planet Nine.

from EarthSky https://ift.tt/2zv27rD

An artist’s concept of a hypothetical planet with a distant sun. Image via Shutterstock/ The Conversation.

by Samantha Lawler, University of Regina

Planet Nine is a theoretical, undiscovered giant planet in the mysterious far reaches of our solar system.

The presence of Planet Nine has been hypothesized to explain everything from the tilt of the sun’s spin axis to the apparent clustering in the orbits of small, icy asteroids beyond Neptune.

But does Planet Nine actually exist?

Discoveries at the edge of our solar system

The Kuiper Belt is a collection of small, icy bodies that orbit the sun beyond Neptune, at distances larger than 30 AU (one astronomical unit or AU is the distance between the Earth and the sun). These Kuiper Belt objects (KBOs) range in size from large boulders to 1,200 miles (2,000 km) across. KBOs are leftover small bits of planetary material that were never incorporated into planets, similar to the asteroid belt.

After Pluto, the second Kuiper Belt Object — 1992 QB1 — was discovered in 1992 by American astronomers David Jewitt and Jane Luu using the 2.2-m telescope at Mauna Kea in Hawaii. Image via NASA.

The discoveries from the most successful Kuiper Belt survey to date, the Outer Solar System Origins Survey (OSSOS), suggest a sneakier explanation for the orbits we see. Many of these KBOs have been discovered to have very elliptical and tilted orbits, like Pluto.

Mathematical calculations and detailed computer simulations have shown that the orbits we see in the Kuiper Belt can only have been created if Neptune originally formed a few AU closer to the sun, and migrated outward to its present orbit. Neptune’s migration explains the pervasiveness of highly elliptical orbits in the Kuiper Belt, and can explain all the KBO orbits we’ve observed, except for a handful of KBOs on extreme orbits that always stay at least 10 AU beyond Neptune.

Proof of Planet Nine?

These extreme orbits have provided the strongest evidence for Planet Nine. The first few that were discovered were all confined to one quadrant of the solar system. Astronomers expect to observe orbits at all different orientations, unless there is an outside force confining them. Finding several extreme KBOs on orbits pointed in the same direction was a hint that something was going on. Two separate groups of researchers calculated that only a large, very distant planet could keep all the orbits confined to part of the solar system, and the theory of Planet Nine was born.

Planet Nine is theorized to be five to 10 times as massive as Earth, with an orbit ranging between 300-700 AU. There have been several published predictions for its location in the solar system, but none of the search teams have yet discovered it. After more than four years of searching, there is still only indirect evidence in favour of Planet Nine.

The search for KBOs

Searching for KBOs requires careful planning, precise calculations and meticulous followup. I am part of the OSSOS, a collaboration of 40 astronomers from eight countries. We used the Canada-France-Hawaii Telescope over five years to discover and track more than 800 new KBOs, nearly doubling the number of known KBOs with well-measured orbits. The KBOs discovered by OSSOS range in size from a few kilometers to over 100 km, and range in discovery distance from a few AU to over 100 AU, with the majority at 40-42 AU in the main Kuiper Belt.

KBOs do not emit their own light: these small, icy bodies only reflect light from the sun. Thus, the biases against detection at larger distances are extreme: if you move a KBO 10 times farther away, it will become 10,000 times fainter. And because of the laws of physics, KBOs on elliptical orbits will spend most of their time at the most distant parts of their orbits. So, while it is easy to find KBOs on elliptical orbits when they are close to the sun and bright, these KBOs spend most time being much fainter and harder to detect.

This means that the KBOs on elliptical orbits are particularly hard to discover, especially the extreme ones that always stay relatively far from the sun. Only a few of these have been found to date and, with current telescopes, we can only discover them when they are near pericenter — the closest point to the sun in their orbit.

This leads to another observation bias that has historically been ignored by many KBO surveys: KBOs in each part of the solar system can only be discovered at certain times of year. Ground-based telescopes are additionally limited by seasonal weather, with discoveries less likely to happen during when cloudy, rainy or windy conditions are more frequent. Discoveries of KBOs are also much less likely near the plane of the Milky Way galaxy, where countless stars make it difficult to find the faint, icy wanderers in telescopic images.

What makes OSSOS unique is that we are very public about these biases in discoveries. And because we understand our biases so well, we can use computer simulations to reconstruct the true shape of the Kuiper Belt after removing these biases.

Adjusting for biases

OSSOS discovered a handful of new extreme KBOs, half of which are outside the confined region, and are statistically consistent with a uniform distribution. A new study (currently in review) corroborates the non-clustered discoveries of OSSOS. A team of astronomers using data from the Dark Energy Survey (DES) found over 300 new KBOs with no clustering of orbits. So now two independent surveys — both of which carefully tracked and reported their observational biases in discovering independent sets of extreme KBOs — have found no evidence for clustered orbits.

All known KBOs with orbits larger than 250 AU. The orbits of KBOs discovered by OSSOS and DES are in many directions; previous surveys with unknown biases discovered them in the same direction. This image was produced using public data from the Minor Planet Center Database. Image via Samantha Lawler/ The Conversation.

All of the extreme KBOs that had been discovered prior to OSSOS and DES were from surveys that did not fully report their directional biases. So we do not know if all these KBOs were discovered in the same quadrant of the solar system because they are actually confined, or because no surveys searched deep enough in the other quadrants. We performed additional simulations that showed that if observations are made only in one season from one telescope, extreme KBOs will naturally only be discovered in one quadrant of the solar system.

Further testing the Planet Nine theory, we looked in detail at the orbits of all known “extreme” KBOs and found that all but the two highest pericentre KBOs can be explained by known physical effects. These two KBOs are outliers, but our previous detailed computer simulations of the Kuiper Belt, which included gravitational effects from Planet Nine, produced a set of “extreme” KBOs with pericenters smoothly ranging from 40 to over 100 AU.

These simulations predict that there should be many KBOs with pericenters as large as the two outliers, but also many KBOs with smaller pericenters, which should be much easier to detect. Why don’t the orbit discoveries match the predictions? The answer may be that the Planet Nine theory does not hold up to detailed observations.

Our observations with a careful survey have discovered KBOs that are not confined by Planet Nine, and our simulations show that the Kuiper Belt should contain different orbits than we observe if Planet Nine exists. Other theories must be invoked to explain the high-pericentre extreme KBOs, but there is no lack of proposed theories in the scientific literature.

Many beautiful and surprising objects remain to be discovered in the mysterious outer solar system, but I don’t believe that Planet Nine is one of them.

Samantha Lawler, Assistant professor of astronomy, University of Regina

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Astronomers think there might not be a Planet Nine.

from EarthSky https://ift.tt/2zv27rD

NVX-CoV2373: Here's How The Coronavirus Vaccine Based On A Flu Shot Works

NVX-CoV2373: Here's How The Coronavirus Vaccine Based On A Flu Shot Works

A new trial has begun in Victoria this week to evaluate a potential vaccine against COVID-19.

The vaccine is called NVX-CoV2373 and is from a US biotech company, Novavax.

The trial will be carried out across Melbourne and Brisbane, and is the first human trial of a vaccine specifically for COVID-19 to take place in Australia.

This vaccine is actually based on a vaccine that was already in development for influenza. But how might it work against SARS-CoV-2, the coronavirus that causes COVID-19?

What’s in the mix?

Vaccines trigger an immune response by introducing the cells of our immune system to a virus in a safe way, without any exposure to the pathogen itself.

All vaccines have to do two things. The first is make our immune cells bind to and “eat up” the vaccine. The second is to activate these immune cells so they’re prepared to fight the current and any subsequent threats from the virus in question.

We often add molecules called adjuvants to vaccines to deliver a danger signal to the immune system, activate immune cells and trigger a strong immune response.

The Novavax vaccine is what we call a “subunit” vaccine because, instead of delivering the whole virus, it delivers only part of it. The element of SARS-CoV-2 in this vaccine is the spike protein, which is found on the surface of the virus.

By targeting a particular protein, a subunit vaccine is a great way to focus the immune response.

However, protein by itself is not very good at binding to and activating the cells of our immune system. Proteins are generally soluble, which doesn’t appeal to immune cells. They like something they can chew on.

So instead of soluble protein, Novavax has assembled the SARS-CoV-2 spike protein into very small particles, called nanoparticles. To immune cells, these nanoparticles look like little viruses, so immune cells can bind to these pre-packaged chunks of protein, rapidly engulfing them and becoming activated.

The Novavax vaccine also contains an adjuvant called Matrix-M. While the nanoparticles deliver a modest danger signal, Matrix-M can be added to deliver a much stronger danger signal and really wake up the immune system.

The spike protein is formed into nanoparticles to attract immune cells, and Matrix-M is added as an adjuvant to further activate immune cells. Author provided

Rethinking an influenza vaccine

The Novavax vaccine for SARS-CoV-2 is based on a vaccine the company was already developing for influenza, called NanoFlu.

The NanoFlu vaccine contains similar parts – nanoparticles with the Matrix-M adjuvant. But it uses a different protein in the nanoparticle (hemagglutinin, which is on the outside of the influenza virus).

In October last year, Novavax started testing NanoFlu in a phase III clinical trial, the last level of clinical testing before a vaccine can be licensed. This trial had 2,650 volunteers and researchers were comparing whether NanoFlu performed as well as Fluzone, a standard influenza vaccine.

An important feature of this trial is participants were over the age of 65. Older people tend to have poorer responses to vaccines, because immune cells become more difficult to activate as we age.

This trial is ongoing, with volunteers to be followed until the end of the year. However, early results suggest NanoFlu can generate significantly higher levels of antibodies than Fluzone – even given the older people in the trial.

Antibodies are small proteins made by our immune cells which bind strongly to viruses and can stop them from infecting cells in the nose and lungs. So increased antibodies with NanoFlu should result in lower rates of infection with influenza.

These results were similar to those released after the phase I trial of NanoFlu, and suggest NanoFlu would be the superior vaccine for influenza.

So the big question is – will the same strategy work for SARS-CoV-2?

The Novavax vaccine is one of several potential COVID-19 vaccines being trialed around the world. Shutterstock

The Australian clinical trial

The new phase I/II trial will enrol around 131 healthy volunteers aged between 18 and 59 to assess the vaccine’s safety and measure how it affects the body’s immune response.

Some volunteers will not receive the vaccine, as a placebo control. The rest will receive the vaccine, in a few different forms.

The trial will test two doses of protein nanoparticles – a low (5 microgram) or a high (25 microgram) dose. Both doses will be delivered with Matrix-M adjuvant but the higher dose will also be tested without Matrix-M.

All groups will receive two shots of the vaccine 21 days apart, except one group that will just get one shot.

This design enables researchers to ask four important questions:

1. can the vaccine induce an immune response?

2. if so, what dose of nanoparticle is best?

3. do you need adjuvant or are nanoparticles enough?

4. do you need two shots or is one enough?

While it’s not yet clear how the vaccine will perform for SARS-CoV-2, Novavax has reported it generated strong immune responses in animals.

And we know NanoFlu performed well and had a good safety profile for influenza. NanoFlu also seemed to work well in older adults, which would be essential for a vaccine for COVID-19.

We eagerly await the first set of results, expected in a couple of months – an impressive turnaround time for a clinical trial. If this initial study is successful, the phase II portion of the trial will begin, with more participants.

The Novavax vaccine joins at least nine other vaccine candidates for SARS-CoV-2 currently in clinical testing around the world.

By Kylie Quinn, Vice-Chancellor's Research Fellow, School of Health and Biomedical Sciences, RMIT University and Kirsty Wilson, Postdoctoral Research Fellow, RMIT University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

sb admin Wed, 05/27/2020 - 10:18

Categories

Medicine

from ScienceBlogs - Where the world discusses science https://ift.tt/2yBQ1MG

NVX-CoV2373: Here's How The Coronavirus Vaccine Based On A Flu Shot Works

A new trial has begun in Victoria this week to evaluate a potential vaccine against COVID-19.

The vaccine is called NVX-CoV2373 and is from a US biotech company, Novavax.

The trial will be carried out across Melbourne and Brisbane, and is the first human trial of a vaccine specifically for COVID-19 to take place in Australia.

This vaccine is actually based on a vaccine that was already in development for influenza. But how might it work against SARS-CoV-2, the coronavirus that causes COVID-19?

What’s in the mix?

Vaccines trigger an immune response by introducing the cells of our immune system to a virus in a safe way, without any exposure to the pathogen itself.

All vaccines have to do two things. The first is make our immune cells bind to and “eat up” the vaccine. The second is to activate these immune cells so they’re prepared to fight the current and any subsequent threats from the virus in question.

We often add molecules called adjuvants to vaccines to deliver a danger signal to the immune system, activate immune cells and trigger a strong immune response.

The Novavax vaccine is what we call a “subunit” vaccine because, instead of delivering the whole virus, it delivers only part of it. The element of SARS-CoV-2 in this vaccine is the spike protein, which is found on the surface of the virus.

By targeting a particular protein, a subunit vaccine is a great way to focus the immune response.

However, protein by itself is not very good at binding to and activating the cells of our immune system. Proteins are generally soluble, which doesn’t appeal to immune cells. They like something they can chew on.

So instead of soluble protein, Novavax has assembled the SARS-CoV-2 spike protein into very small particles, called nanoparticles. To immune cells, these nanoparticles look like little viruses, so immune cells can bind to these pre-packaged chunks of protein, rapidly engulfing them and becoming activated.

The Novavax vaccine also contains an adjuvant called Matrix-M. While the nanoparticles deliver a modest danger signal, Matrix-M can be added to deliver a much stronger danger signal and really wake up the immune system.

The spike protein is formed into nanoparticles to attract immune cells, and Matrix-M is added as an adjuvant to further activate immune cells. Author provided

Rethinking an influenza vaccine

The Novavax vaccine for SARS-CoV-2 is based on a vaccine the company was already developing for influenza, called NanoFlu.

The NanoFlu vaccine contains similar parts – nanoparticles with the Matrix-M adjuvant. But it uses a different protein in the nanoparticle (hemagglutinin, which is on the outside of the influenza virus).

In October last year, Novavax started testing NanoFlu in a phase III clinical trial, the last level of clinical testing before a vaccine can be licensed. This trial had 2,650 volunteers and researchers were comparing whether NanoFlu performed as well as Fluzone, a standard influenza vaccine.

An important feature of this trial is participants were over the age of 65. Older people tend to have poorer responses to vaccines, because immune cells become more difficult to activate as we age.

This trial is ongoing, with volunteers to be followed until the end of the year. However, early results suggest NanoFlu can generate significantly higher levels of antibodies than Fluzone – even given the older people in the trial.

Antibodies are small proteins made by our immune cells which bind strongly to viruses and can stop them from infecting cells in the nose and lungs. So increased antibodies with NanoFlu should result in lower rates of infection with influenza.

These results were similar to those released after the phase I trial of NanoFlu, and suggest NanoFlu would be the superior vaccine for influenza.

So the big question is – will the same strategy work for SARS-CoV-2?

The Novavax vaccine is one of several potential COVID-19 vaccines being trialed around the world. Shutterstock

The Australian clinical trial

The new phase I/II trial will enrol around 131 healthy volunteers aged between 18 and 59 to assess the vaccine’s safety and measure how it affects the body’s immune response.

Some volunteers will not receive the vaccine, as a placebo control. The rest will receive the vaccine, in a few different forms.

The trial will test two doses of protein nanoparticles – a low (5 microgram) or a high (25 microgram) dose. Both doses will be delivered with Matrix-M adjuvant but the higher dose will also be tested without Matrix-M.

All groups will receive two shots of the vaccine 21 days apart, except one group that will just get one shot.

This design enables researchers to ask four important questions:

1. can the vaccine induce an immune response?

2. if so, what dose of nanoparticle is best?

3. do you need adjuvant or are nanoparticles enough?

4. do you need two shots or is one enough?

While it’s not yet clear how the vaccine will perform for SARS-CoV-2, Novavax has reported it generated strong immune responses in animals.

And we know NanoFlu performed well and had a good safety profile for influenza. NanoFlu also seemed to work well in older adults, which would be essential for a vaccine for COVID-19.

We eagerly await the first set of results, expected in a couple of months – an impressive turnaround time for a clinical trial. If this initial study is successful, the phase II portion of the trial will begin, with more participants.

The Novavax vaccine joins at least nine other vaccine candidates for SARS-CoV-2 currently in clinical testing around the world.

By Kylie Quinn, Vice-Chancellor's Research Fellow, School of Health and Biomedical Sciences, RMIT University and Kirsty Wilson, Postdoctoral Research Fellow, RMIT University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

sb admin Wed, 05/27/2020 - 10:18

Categories

Medicine

from ScienceBlogs - Where the world discusses science https://ift.tt/2yBQ1MG

Late May: Moon in Leo the Lion

As darkness falls these next several evenings – May 28, 29, and 30, 2020 – watch the moon as it travels in front of the constellation Leo the Lion. When the moon first enters Leo, it’ll display a rather wide waxing crescent phase. When the moon finally leaves Leo a few days later, it’ll show a waxing gibbous phase. Midway though its trek in Leo, the moon will exhibit its half-illuminated first quarter phase.

By the way, the moon reaches its first quarter phase on May 30, at 3:30 UTC. At United States time zones, that means the first quarter moon comes on May 29, at 11:30 p.m EDT, 10:30 p.m. CDT, 9:30 p.m. MDT and 8:30 p.m. PDT.

On May 28 and 29, 2020, use the moon to find Regulus, the brightest star in the constellation Leo the Lion. This blue-white gem of a star is of 1st-magnitude brightness and is the 21st brightest star to light up the nighttime sky.

The moon is rather close to Regulus for only a few days each month. So when the moon is no longer there to guide you, let the Big Dipper serve as your handy guide to this star. The two bowl stars on the handle side of the Big Dipper faithfully point to Regulus.

Click on Heavens-Above Moon to find out the moon’s present phase and its present position on the zodiac.

Use the Big Dipper to locate the bright stars Arcturus and Regulus.

Regulus is a blue-white gem of a star, its color revealing that this star has a high surface temperature. Considering that Regulus is nearly 80 light-years away, it must be quite luminous (intrinsically bright) to shine at 1st-magnitude brightness in Earth’s sky. Regulus is several hundred times more luminous than our sun, and at Regulus’ distance, our sun would be not even be visible to the naked eye.

Normally, a star’s blue-white color indicates that the star is in the heyday of youth (only 50 to 100 million years old). But Regulus has a very close companion star which cannot be seen through the telescope but only detected with a spectroscope. It’s thought that Regulus’ companion could be a white dwarf star, in which case Regulus and its companion star would have to be at least a billion years old. Possibly, mass transfer of material from one star to the other in this close-knit binary star system acts as a fountain of youth, keeping Regulus young in its old age.

Regulus is the only 1st magnitude star to sit almost squarely on the ecliptic – the sun’s apparent yearly pathway in front of the constellations of the zodiac. Of course, the sun’s apparent motion in front of the stars is really a reflection of our planet Earth’s revolution around the sun.

Looking at the sky chart below, notice that Regulus dots a backwards question mark of stars, called “The Sickle.” The Sickle outlines the Lion’s head and mane, whereas the star Denebola (whose name means “tail of the lion” in Arabic) marks the Lion’s tail.

Chart of the constellation Leo via the IAU. The ecliptic depicts the annual pathway of the sun in front of the constellations of the zodiac. The sun passes in front of the constellation Leo each year from around August 10 to September 17, and has its yearly conjunction with the star Regulus on or near August 23.

Bottom line: These next several nights – May 28, 29 and 30, 2020 – use the moon to locate the constellation Leo and the star Regulus. Once the moon leaves the evening sky, starting around mid-June 2020, try to piece together the starlit figure of the Lion in a dark sky.

from EarthSky https://ift.tt/36AGDpc

As darkness falls these next several evenings – May 28, 29, and 30, 2020 – watch the moon as it travels in front of the constellation Leo the Lion. When the moon first enters Leo, it’ll display a rather wide waxing crescent phase. When the moon finally leaves Leo a few days later, it’ll show a waxing gibbous phase. Midway though its trek in Leo, the moon will exhibit its half-illuminated first quarter phase.

By the way, the moon reaches its first quarter phase on May 30, at 3:30 UTC. At United States time zones, that means the first quarter moon comes on May 29, at 11:30 p.m EDT, 10:30 p.m. CDT, 9:30 p.m. MDT and 8:30 p.m. PDT.

On May 28 and 29, 2020, use the moon to find Regulus, the brightest star in the constellation Leo the Lion. This blue-white gem of a star is of 1st-magnitude brightness and is the 21st brightest star to light up the nighttime sky.

The moon is rather close to Regulus for only a few days each month. So when the moon is no longer there to guide you, let the Big Dipper serve as your handy guide to this star. The two bowl stars on the handle side of the Big Dipper faithfully point to Regulus.

Click on Heavens-Above Moon to find out the moon’s present phase and its present position on the zodiac.

Use the Big Dipper to locate the bright stars Arcturus and Regulus.

Regulus is a blue-white gem of a star, its color revealing that this star has a high surface temperature. Considering that Regulus is nearly 80 light-years away, it must be quite luminous (intrinsically bright) to shine at 1st-magnitude brightness in Earth’s sky. Regulus is several hundred times more luminous than our sun, and at Regulus’ distance, our sun would be not even be visible to the naked eye.

Normally, a star’s blue-white color indicates that the star is in the heyday of youth (only 50 to 100 million years old). But Regulus has a very close companion star which cannot be seen through the telescope but only detected with a spectroscope. It’s thought that Regulus’ companion could be a white dwarf star, in which case Regulus and its companion star would have to be at least a billion years old. Possibly, mass transfer of material from one star to the other in this close-knit binary star system acts as a fountain of youth, keeping Regulus young in its old age.

Regulus is the only 1st magnitude star to sit almost squarely on the ecliptic – the sun’s apparent yearly pathway in front of the constellations of the zodiac. Of course, the sun’s apparent motion in front of the stars is really a reflection of our planet Earth’s revolution around the sun.

Looking at the sky chart below, notice that Regulus dots a backwards question mark of stars, called “The Sickle.” The Sickle outlines the Lion’s head and mane, whereas the star Denebola (whose name means “tail of the lion” in Arabic) marks the Lion’s tail.

Chart of the constellation Leo via the IAU. The ecliptic depicts the annual pathway of the sun in front of the constellations of the zodiac. The sun passes in front of the constellation Leo each year from around August 10 to September 17, and has its yearly conjunction with the star Regulus on or near August 23.

Bottom line: These next several nights – May 28, 29 and 30, 2020 – use the moon to locate the constellation Leo and the star Regulus. Once the moon leaves the evening sky, starting around mid-June 2020, try to piece together the starlit figure of the Lion in a dark sky.

from EarthSky https://ift.tt/36AGDpc