When you're cutting meat and fish, it's essential to use a surface that you can thoroughly clean afterwards.
When it comes to kitchen hygiene, bear in mind that it's best to have a chopping board that can stand cleaning at high temperatures.
Climate change is causing the widespread warming of our land, oceans and atmosphere. Apart from this, it also has the potential to increase volcanic activity, affect the size of eruptions, and alter the “cooling effect” that follows volcanic eruptions.
Any of these scenarios could have far-reaching consequences. Yet we don’t fully understand the impact a warming climate could have on volcanic activity.
The Fagradalsfjall volcano is located some 30km from Iceland’s capital, Reykjavik.
First, let’s take a look at volcanic regions covered in ice. There’s a long-established link between the large-scale melting of ice in active volcanic regions and increased eruptions.
Research on Iceland’s volcanic systems has identified a heightened period of activity related to the large-scale ice melt at the end of the last ice age. The average eruption rates were found to be up to 100 times higher after the end of the last glacial period, compared to the earlier colder glacial period. Eruptions were also smaller when ice cover was thicker.
But why is this the case? Well, as glaciers and ice sheets melt, pressure is taken off Earth’s surface and there are changes in the forces (stress) acting on rocks within the crust and upper mantle. This can lead to more molten rock, or “magma”, being produced in the mantle – which can feed more eruptions.
The changes can also affect where and how magma is stored in the crust, and can make it easier for magma to reach the surface.
Magma generation beneath Iceland is already increasing due to a warming climate and melting glaciers.
The intense ash-producing eruption of Iceland’s Eyjafjallajökull volcano in 2010 was the result of an explosive interaction between hot magma and cold glacial melt water. Based on what we know from the past, an increase in Iceland’s melting ice could lead to larger and more frequent volcanic eruptions.
The Eyjafjallajokull is an active volcano covered by an ice cap. Back in 2010, an explosive eruption led to flights across Europe being halted. (Arnar Thorisson/AP)
But what about volcanic regions that aren’t covered in ice – could these also be affected by global warming?
Possibly. We know climate change is increasing the severity of storms and other weather events in many parts of the world. These weather events may trigger more volcanic eruptions.
On December 6 2021, an eruption at one of Indonesia’s most active volcanoes, Mount Semeru, caused ashfall, pyroclastic flows and volcanic mudflows (called “lahars”) that claimed the lives of at least 50 people.
The Semeru eruption left nearby villages covered in ash – forcing residents to flee. (Antara TV/Wikimedia Commons, CC BY)
Local authorities hadn’t expected the scale of the eruption. As for the cause, they said several days of heavy rain had destabilised the dome of lava in the volcano’s summit crater. This led to the dome collapsing, which reduced pressure on the magma below and triggered an eruption.
Signals of volcanic unrest are usually obtained from changes in volcanic systems (such as earthquake activity), changes in gas emissions from the volcano, or small changes in the shape of the volcano (which can be detected by ground-based or satellite monitoring).
Predicting eruptions is already an incredibly complex task. It will become even more difficult as we begin to factor in risk posed by severe weather which could destabilize parts of a volcano.
Some scientists suspect increased rainfall led to the damaging 2018 Kīlauea eruption in Hawaii. This was preceded by months of heavy rainfall, which infiltrated the earth and increased underground water pressure within the porous rock. They believe this could have weakened and fractured the rock, facilitating the movement of magma and triggering the eruption.
But other experts disagree, and say there’s no substantial link between rainfall events and eruptions at Kīlauea volcano.
Rain-influenced volcanism has also been proposed at other volcanoes around the world, such as the Soufrière Hills volcano in the Caribbean, and Piton de la Fournaise on Réunion Island in the Indian Ocean.
There’s another layer we can’t ignore when it comes to assessing the potential link between climate change and volcanic activity. That is: volcanoes themselves can influence the climate.
An eruption can lead to cooling or warming, depending on the volcano’s geographical location, the amount and composition of ash and gas erupted, and how high the plume reaches into the atmosphere.
Volcanic injections that were rich in sulphur dioxide gas have had the strongest climatic impact recorded in historic times. Sulphur dioxide eventually condenses to form sulfate aerosols in the stratosphere – and these aerosols reduce how much heat reaches Earth’s surface, causing cooling.
As the climate warms, research shows this will change how volcanic gases interact with the atmosphere. Importantly, the outcome won’t be the same for all eruptions. Some scenarios show that, in a warmer atmosphere, small to medium-sized eruptions could reduce the cooling effect of volcanic plumes by up to 75%.
These scenarios assume the “tropopause” (the boundary between the troposphere and stratosphere) will increase in height as the atmosphere warms. But since the volcano’s eruption column will stay the same, the plume carrying sulphur dioxide will be less likely to reach the upper atmosphere – where it would have the largest impact on the climate.
On the other hand, more powerful but less frequent volcanic eruptions could lead to a greater cooling effect. That’s because as the atmosphere gets warmer, plumes of ash and gas emitted from powerful eruptions are predicted to rise higher into the atmosphere, and spread rapidly from the tropics to higher latitudes.
One recent study has suggested the major Hunga Tonga-Hunga Ha’apai volcanic eruption in January may contribute to global warming, by pumping massive amounts of water vapor (a greenhouse gas) into the stratosphere.
Heather Handley, Associate Professor of Volcanology and Geoscience Communication, University of Twente and Adjunct Associate Professor, Monash University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Presidents and state governors have the authority to declare states of emergency when there is a potentially life-threatening situation and the resources routinely allocated to the responding agencies are insufficient for dealing with the situation.
In late July, 2022, for example, the governor of Kentucky declared a state of emergency following devastating flooding in the eastern part of the state. The governor requested and received federal assistance to help respond to the floods. The declaration didn’t mean that more flooding was expected. It just made extra resources available for rescuing stranded individuals and providing essential services, like shelter and drinking water, to displaced people.
Similarly, the monkeypox emergency declaration doesn’t mean that the government expects millions more cases in the next month. It is about helping health agencies get the vaccines and other tools they need to slow the spread of the virus.
No. The main thing the emergency declaration does is enable the U.S. Department of Health and Human Services to get more of the funding and other resources that it needs to protect the public from a more widespread monkeypox outbreak. At this point, monkeypox is an emergency for the U.S. government’s public health agencies to deal with. It is not an emergency for the public right now. The goal of the emergency declaration is to prevent monkeypox from becoming a more widespread threat to public health.
As of early August, 2022, there were 7,000 cases of monkeypox in the U.S. so far, with cases spread across several states.
Mario Guti/iStock via Getty Images
According to the Department of Health and Human Services, there are two key actions that will be taken at this stage of the outbreak.
First, the government will intensify its efforts to protect at-risk communities by trying to get new vaccine doses faster and increasing access to testing and treatment. Officials are also working with LGBTQI+ communities to educate men who have sex with men about reducing their risk of contracting the monkeypox virus.
Second, the emergency declaration calls for all states and other jurisdictions to share data with the Centers for Disease Control and Prevention. It also authorizes the Centers for Medicare and Medicaid Services to collect data about monkeypox testing and hospitalizations. These actions will give the Department of Health and Human Services better data about where monkeypox is occurring so the agency can distribute vaccines and the antiviral medication tecovirimat (Tpoxx) to the states and cities that have the greatest need for them.
The Jynneos vaccine is the only monkeypox-specific vaccine currently approved by the U.S. Food and Drug Administration. Increased demand for monkeypox vaccines has used up most of the world’s existing supply of Jynneos. It will take several months for additional doses to be manufactured. These new doses are expected to be delivered between the end of 2022 and the middle of 2023.
However, the emergency declaration explains that the government may use a “new dose-sparing approach that could increase the number of doses available, up to five-fold” – an approach called fractional dosing – to make the vaccine available to more people.
The package insert for the Jynneos vaccine specifies that it should be given in two 0.5-milliliter doses four weeks apart. The emergency declaration outlines a strategy in which people are instead given two 0.1-milliliter doses. If the lower dose is as effective as the full dose, up to five times more people could be vaccinated with the same amount of vaccine.
Fractional dosing is not a new strategy. During a 2016 yellow fever epidemic in sub-Saharan Africa, clinical trials showed that a small portion of the approved vaccine dose was just as effective as a full dose at conferring immunity.
For the current monkeypox outbreak in the U.S., the National Institutes of Health will evaluate whether a smaller dose of monkeypox vaccine might be effective, as well as whether one shot provides about as much protection as two doses.
The emergency declaration does not call for schools, businesses, nursing homes or individuals to change their behaviors in any way or to prepare for any sorts of future restrictions. Declaring monkeypox a public health emergency just makes more resources available to help the government protect the public from this infectious disease.
Kathryn H. Jacobsen, William E. Cooper Distinguished University Chair, Professor of Health Studies, University of Richmond
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Over the past few decades, Earth’s rotation around its axis – which determines how long a day is – has been speeding up. This trend has been making our days shorter; in fact, in June 2022 we set a record for the shortest day over the past half a century or so.
But despite this record, since 2020 that steady speedup has curiously switched to a slowdown – days are getting longer again, and the reason is so far a mystery.
While the clocks in our phones indicate there are exactly 24 hours in a day, the actual time it takes for Earth to complete a single rotation varies ever so slightly. These changes occur over periods of millions of years to almost instantly – even earthquakes and storm events can play a role.
It turns out a day is very rarely exactly the magic number of 86,400 seconds.
Over millions of years, Earth’s rotation has been slowing down due to friction effects associated with the tides driven by the Moon. That process adds about about 2.3 milliseconds to the length of each day every century. A few billion years ago an Earth day was only about 19 hours.
For the past 20,000 years, another process has been working in the opposite direction, speeding up Earth’s rotation. When the last ice age ended, melting polar ice sheets reduced surface pressure, and Earth’s mantle started steadily moving toward the poles.
Just as a ballet dancer spins faster as they bring their arms toward their body – the axis around which they spin – so our planet’s spin rate increases when this mass of mantle moves closer to Earth’s axis. And this process shortens each day by about 0.6 milliseconds each century.
Over decades and longer, the connection between Earth’s interior and surface comes into play too. Major earthquakes can change the length of day, although normally by small amounts. For example, the Great Tōhoku Earthquake of 2011 in Japan, with a magnitude of 8.9, is believed to have sped up Earth’s rotation by a relatively tiny 1.8 microseconds.
Apart from these large-scale changes, over shorter periods weather and climate also have important impacts on Earth’s rotation, causing variations in both directions.
The fortnightly and monthly tidal cycles move mass around the planet, causing changes in the length of day by up to a millisecond in either direction. We can see tidal variations in length-of-day records over periods as long as 18.6 years. The movement of our atmosphere has a particularly strong effect, and ocean currents also play a role. Seasonal snow cover and rainfall, or groundwater extraction, alter things further.
Since the 1960s, when operators of radio telescopes around the planet started to devise techniques to simultaneously observe cosmic objects like quasars, we have had very precise estimates of Earth’s rate of rotation.
Using radio telescopes to measure Earth’s rotation involves observations of radio sources like quasars. NASA Goddard.
A comparison between these estimates and an atomic clock has revealed a seemingly ever-shortening length of day over the past few years.
But there’s a surprising reveal once we take away the rotation speed fluctuations we know happen due to the tides and seasonal effects. Despite Earth reaching its shortest day on June 29 2022, the long-term trajectory seems to have shifted from shortening to lengthening since 2020. This change is unprecedented over the past 50 years.
The reason for this change is not clear. It could be due to changes in weather systems, with back-to-back La Niña events, although these have occurred before. It could be increased melting of the ice sheets, although those have not deviated hugely from their steady rate of melt in recent years. Could it be related to the huge volcano explosion in Tonga injecting huge amounts of water into the atmosphere? Probably not, given that occurred in January 2022.
Scientists have speculated this recent, mysterious change in the planet’s rotational speed is related to a phenomenon called the “Chandler wobble” – a small deviation in Earth’s rotation axis with a period of about 430 days. Observations from radio telescopes also show that the wobble has diminished in recent years; the two may be linked.
One final possibility, which we think is plausible, is that nothing specific has changed inside or around Earth. It could just be long-term tidal effects working in parallel with other periodic processes to produce a temporary change in Earth’s rotation rate.
Precisely understanding Earth’s rotation rate is crucial for a host of applications – navigation systems such as GPS wouldn’t work without it. Also, every few years timekeepers insert leap seconds into our official timescales to make sure they don’t drift out of sync with our planet.
If Earth were to shift to even longer days, we may need to incorporate a “negative leap second” – this would be unprecedented, and may break the internet.
The need for negative leap seconds is regarded as unlikely right now. For now, we can welcome the news that – at least for a while – we all have a few extra milliseconds each day.
Matt King, Director of the ARC Australian Centre for Excellence in Antarctic Science, University of Tasmania and Christopher Watson, Senior Lecturer, School of Geography, Planning, and Spatial Sciences, University of Tasmania
This article is republished from The Conversation under a Creative Commons license. Read the original article.
This is a crucial stage: in humans, many pregnancies are lost around this stage, and we don’t really know why. Having models provides a way to better understand what can go wrong, and possibly insights into what we may be able to do about it.
What’s particularly interesting about the newly published model is its very complex structure; not only does it mimic the cell specification and layout of an early-stage body plan – including precursors of heart, blood, brain and other organs – but also the “support” cells like those found in the placenta and other tissues required to establish and maintain a pregnancy.
This eight-day-old mouse embryo model has a beating heart, a yolk sac, a placenta and an emerging blood circulation. The Weizmann Institute of Science.
The earliest stages of pregnancy are difficult to study in most animals. The embryos are microscopic, tiny clusters of cells, difficult to locate and observe within the uterus.
But we do know that at this stage of development, things can go awry; for example, environmental factors can influence and interfere with development, or cells fail to receive the right signals to fully form the spinal cord, such as in spina bifida. Using models like this, we can start to ask why.
However, even though these models are a powerful research tool, it is important to understand they are not embryos.
They replicate only some aspects of development, but not fully reproduce the cellular architecture and developmental potential of embryos derived after fertilization of eggs by sperm – so-called natural embryos.
The team behind this work emphasizes they were unable to develop these models beyond eight days, while a normal mouse pregnancy is 20 days long.
The field of embryo modeling is progressing rapidly, with new advances emerging every year.
In 2021, several teams managed to get human pluripotent stem cells (cells that can turn into any other type of cell) to self-aggregate in a Petri dish, mimicking the “blastocyst”. This is the earliest stage of embryonic development just before the complex process of implantation, when a mass of cells attach to the wall of the uterus.
Researchers using these human embryo models, often called blastoids, have even been able to start to explore implantation in a dish, but this process is much more challenging in humans than it is in mice.
Growing human embryo models of the same complexity that has now been achieved with a mouse model remains a distant proposition, but one we should still consider.
Importantly, we need to be aware of how representative such a model would be; a so-called synthetic embryo in a Petri dish will have its limitations on what it can teach us about human development, and we need to be conscious of that.
No embryonic modeling can happen without a source of stem cells, so when it comes to thinking about the future use of this technology, it is vital to ask – where are these cells coming from? Are they human embryonic stem cells (derived from a blastocyst), or are they induced pluripotent stem cells? The latter can be made in the lab from skin, or blood cells, for example, or even derived from frozen samples.
An important consideration is whether using cells for this particular type of research – trying to mimic an embryo in a dish – requires any specific consent. We should be thinking more about how this area of research will be governed, when should it be used, and by whom.
However, it is important to recognize that there are existing laws and international stem cell research guidelines that provide a framework to regulate this area of research.
In Australia, research involving human stem cell embryo models would require licensing, similar to that required for the use of natural human embryos under law that has been in place since 2002. However, unlike other jurisdictions, Australian law also dictates how long researchers can grow human embryo models, a restriction that some researchers would like to see changed.
Regardless of these or other changes to how and when human embryo research is conducted, there needs to be greater community discourse around this subject before a decision is made.
There is a distinction between banning the use of this technology and technologies like cloning in humans for reproductive use, and allowing research using embryo models to advance our understanding of human development and developmental disorders that we can’t answer by any other means.
The science is rapidly advancing. While mostly in mice at this stage, now is the time to discuss what this means for humans, and consider where and how we draw the line in the sand as the science evolves.
Megan Munsie, Professor Emerging Technologies (Stem Cells), The University of Melbourne
This article is republished from The Conversation under a Creative Commons license. Read the original article.
The Jynneos vaccine is produced by Bavarian Nordic, a small company in Denmark. The vaccine is for the prevention of smallpox and monkeypox disease in adults ages 18 and older who are at high risk for infection with either virus. It was approved in Europe in 2013 and by the U.S. Food and Drug Administration in 2019.
The Jynneos vaccine is given in two doses four weeks apart and contains a live vaccinia virus. Vaccinia normally infects cattle and is a type of poxvirus, a family of viruses that includes smallpox and monkeypox. The virus in this vaccine has been crippled – or attenuated – so that it is no longer able to replicate in cells.
This vaccine is good at protecting those who are at high risk for monkeypox from getting infected before exposure and can also lessen the severity of disease post-infection. It is effective against smallpox as well as monkeypox. Until the recent monkeypox outbreak, this vaccine was primarily given to health care workers or people who have had confirmed or suspected monkeypox exposure.
Both the Jynneos and ACAM2000 vaccines use the vaccinia virus, shown here, to produce immunity to smallpox and monkeypox.
The ACAM2000 vaccine was approved by the FDA in 2007 for protection against smallpox disease. This vaccine is also based on vaccinia virus, however the version of the vaccinia virus in the ACAM2000 vaccine is able to replicate in a person’s cells. Because of this, the ACAM2000 vaccine can be associated with serious side effects. These can include severe skin infections as well as potentially life-threatening heart problems in vulnerable people. Another potential issue with the ACAM2000 vaccine is that it is more complicated to administer compared to a normal shot.
The U.S. government has over 200 million doses of ACAM2000 stockpiled in case of a biological weapon attack of smallpox. But despite the adequate supply of the vaccine, ACAM2000 is not being used to vaccinate against monkeypox because of the risk of serious adverse side effects. For now, only designated U.S. military personnel and laboratory researchers who work with certain poxviruses may receive this vaccine.
According to the U.S. Centers for Disease Control, there is not yet any data available on the effectiveness of either vaccine in the current outbreak of monkeypox. But there is older data available from animal studies, clinical trials and studies in Africa.
A number of clinical trials done during the approval process for the Jynneos vaccine show that when given to a person, it triggers a strong antibody response on par with the ACAM2000 vaccine. An additional study done in nonhuman primates showed that vaccinated animals that were infected with monkeypox survived 80% to 100% of the time, compared with zero to 40% survival in unvaccinated animals.
Another use of the Jynneos vaccine is as a post-exposure prophylaxis, or PEP, meaning the vaccine can be effective even when given after exposure to the virus. Because the monkeypox virus incubates in a person’s body for six to 14 days, the body of someone who gets the Jynneos vaccine shortly after being exposed will produce antibodies that can help fight off infection and protect against a serious monkeypox case.
The ACAM2000 data is older and less precise but shows strong protection. Researchers tested the vaccine during an outbreak of monkeypox in central Africa in the 1980s. Although the study was small and didn’t directly test vaccine efficacy, the authors concluded that unvaccinated people faced an 85% higher risk of being infected than vaccinated people.
According to the CDC, a previous smallpox vaccination does provide some protection against monkeypox, though that protection wanes over time. Experts advise that anyone who had the smallpox vaccine more than three years ago and is at increased risk for monkeypox get the monkeypox vaccine.
In California and New York City, demand for vaccines has been high among at-risk communities.
At the national level, anyone who has had close contact with an infected person, who has a weakened immune system or who had dermatitis or eczema is eligible for a Jynneos vaccine.
Some state and local governments are also making vaccines available to people in communities at higher risk for monkeypox. For example, New York City is allowing men who have sex with men and who have had multiple sexual partners in the past 14 days to get vaccinated.
As of July 29, 2022, a little over 300,000 doses have been shipped to points of care or administered, with another 700,000 already allocated to states across the U.S. However, demand is far outpacing supply. Public health officials acknowledge that vaccine supply shortages have resulted in long lines and clinics having to close when they run out of vaccines. The issues have been magnified by technical problems with online booking systems, particularly in New York City.
To help boost supply, the U.S. has ordered nearly 7 million doses of the Jynneos vaccine, which are expected to arrive over the coming months.
Although federal health officials advise against withholding the second dose, some places – including Washington, D.C., and New York City – are withholding the second dose until more become available. This strategy is being used in Britain and Canada as well to vaccinate as many people as possible at least one time.
A previous study reported that a single shot of the Jynneos vaccine protected monkeys infected with monkeypox and that this protection lasted for at least two years. If this holds up in the real world, it would support withholding second doses in favor of immunizing more Americans. This would be key as many health experts expect the virus to continue spreading, furthering increasing demand of the vaccine.
Maureen Ferran, Associate Professor of Biology, Rochester Institute of Technology
This article is republished from The Conversation under a Creative Commons license. Read the original article.
