Aspen trees increase due to reintroduction of wolves to US national park
The reintroduction of wolves to the park in the early 1990s led to the elk population dropping sharply. The authors of the study published in Forest Ecology and Management believe this is the main reason for the resurgence of aspen trees. By looking at the particular areas where aspen trees grow over a number of years, they were able to see what had changed. Aspen trees which are also called Populus tremula, because of the way its leaves tremble, attract a wide range of wildlife.
Luke Painter ecologist at Oregon State University and lead author told the website Live Science: "Aspen are a key species for biodiversity. The canopy is more open than it is with conifers and you get filtering light that creates a habitat that supports a lot of diversity of plants."While the aspen is recovering they are not out of the woods yet. Bison also eat the young aspen shoots and numbers appear to be increasing. Overall, researchers say it shows what the effect of introducing a predator at the top of the food chain like a wolf can have on biodiversity.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
The Guardian
an hour ago
- The Guardian
Covid cases rising in US as officials plan to restrict booster vaccines
Covid is on the rise again in the US, as children begin returning to school and as officials plan to restrict booster shots. While cases are increasing less quickly than at the start of other surges, it is too soon to tell how big the current late-summer wave could get – and with highly varied immune responses from prior infections and vaccinations, it is difficult to know how severe illness could be, experts said. The risks of a wave are compounded by new vaccine restrictions from the Trump administration. 'If you're vaccinated against Covid-19, you're less likely to get infected,' said Andrew Pekosz, a virologist at Johns Hopkins University. 'But we haven't gotten a lot of people vaccinated for the past few years, and with the current recommendations changing, it's even less likely.' Future waves could become more severe as vaccination lags and immunity drops, Pekosz said. Several key measurements – including wastewater data, test positivity and emergency room visits – indicate a new rise in infections. In the past, Covid has surged about twice a year, usually in the summer and the winter. But the pattern can change, as it does with other respiratory viruses – with late or early starts to the season and curveballs like double peaks. 'Each year has been different, so in some ways, this is more of the same,' said Sam Scarpino, a professor of health sciences at Northeastern University. Cases are increasing or probably increasing in 26 US states, especially in the south and midwest, according to the US Centers for Disease Control and Prevention (CDC). 'In the snapshot that we're seeing right now, increases are happening at a relatively low rate, and that would indicate that we probably aren't going to peak at a very high level. But again, this is early in this summer surge, so we really have to keep monitoring the data and paying attention to what it's telling us,' Pekosz said. The variants currently spreading around the globe have known immune-evasion properties, Scarpino said. 'You can look at the rise that we're seeing, the fact that we know it's an immune-escape variant, and I think we can be pretty confident that there's some kind of wave coming,' Scarpino said. 'Whether it's going to be large or small, I don't think we could really say one way or the other.' But 'the vaccines are still providing some protection,' he said. 'It's never too late to get the booster.' Yet officials softened the recommendation for children on Covid vaccines, and they removed the suggestion entirely for pregnant people, despite the clear benefits of the shot in reducing the risk of severe illness and death during pregnancy. A new, more effective Covid shot from Moderna and the Covid shot from Novavax were approved only for people over 65 or people over the age of 12 with health conditions. The independent advisers to the US Food and Drug Administration (FDA) recommended that vaccine manufacturers once again update booster shots this fall to a more recent variant. Covid boosters are usually recommended for all adults. But this fall, the boosters may be limited to older people and those with health conditions, FDA officials wrote in May. 'So it's a big question mark, going into the fall, is who it's going to be approved for,' Scarpino said. 'If it's not approved, can you still pay out of pocket for it? How much is it going to cost? And then are there going to be supply chain issues?' Health officials have also called for placebo trials for the boosters to judge their benefit to people without pre-existing conditions – but such trials would be unethical and extremely difficult to conduct, experts say. 'Clearly, the guidelines right now are focused on the populations that are more prone to have severe disease and severe outcomes. It's always been good to vaccinate that population,' Pekosz said. But the Trump administration is moving away from the approach of immunizing broad swaths of the population – especially those most likely to get and pass the virus on, like children, he said. 'If you vaccinate broadly, you can reduce the spread of Covid-19 in the population,' Pekosz said. 'The benefit, to me, is very clearly on the side of getting vaccinated.' Some of the pre-existing conditions proposed by FDA officials include asthma, diabetes, depression and physical inactivity. According to that list, 'basically everybody's eligible for one of the vaccines,' Scarpino said. And doctors, including pediatricians, may also prescribe vaccines for off-label use. Yet the more restrictions are placed on vaccination, the harder it is to reach even the people who need it most, Pekosz noted. Antivirals like Paxlovid could also see wider use, the experts said. 'We shouldn't forget about the antivirals,' Pekosz said. 'Those don't seem to be the target of more restrictive use by the CDC or the FDA, so those will be available for people if they do get infected.' A program to make Paxlovid more affordable to those who need it is slated to end in December. 'The benefits of antiviral treatment are very clear with respect to hospitalization and mortality decreases,' Pekosz said. Paxlovid is still highly effective against current variants, Scarpino said. 'There's a whole bunch of good reasons to get it.' Rates of hospitalizations and deaths in recent waves have dropped among adults compared with earlier Covid waves, but the virus remains deadly. An estimated 35,000 to 54,000 people in the US have died of Covid since October. Children continue to see hospitalizations rates from Covid similar to previous years. Covid cases can be less severe because of immunity – from prior infection or from vaccination. 'It's not so much that the virus has become less dangerous, it's that we have immunity, so we fight off the virus more efficiently than we did early in the pandemic,' Pekosz said. That's why vaccinations remain a key part of controlling Covid, he said. Without boosters, people become more susceptible to severe illness and death. About 23% of adults had received updated Covid boosters as of April. About 5.6% of children aged six months to four years are vaccinated against Covid, and about 15% of children aged five to 17 are vaccinated, according to the CDC. 'Children's cases are always surging, because children don't have much immunity to Covid,' Pekosz said. 'Covid cases are really occurring in children at a very high level right now. It's not nearly as dangerous in children as it is in adults, but it still causes a lot of hospitalizations in children.' Hospitalizations and deaths are not the only ways to measure the damage and disruption wrought by Covid. While the Trump administration has not released updated data on long Covid, an estimated 5.3% of all adults in the US said they were currently experiencing long-term Covid symptoms as of September. Even in times of lower transmission, Covid still circulates, with 149 deaths in the week ending 28 June, the last week for which the CDC shares full mortality data. 'It's still a little surprising that it's around all year,' said Pekosz. During lull times, 'we're not seeing it disappear completely, like we do with other respiratory viruses.' When it comes to keeping rates of Covid low, 'it's all the same stuff we usually go over,' Pekosz said – getting vaccinated, taking precautions like masking and using air purifiers, and staying home if you're sick. 'But it's just a very different environment these days. When the government doesn't use the science to drive their decision making, you can see the confusion that it puts into the general public.'
The Independent
4 hours ago
- The Independent
Male contraceptive pill appears to be safe without side effects in early trials
A male birth control pill has been found to be safe in early-stage clinical trials without any negative side effects, researchers have said. The new hormone-free pill, which aims to decrease sperm count reversibly, was found to be safe in a trial of 16 male volunteers. For decades, the choice of contraception for men has been limited to condoms and vasectomy. Weight gain, acne, mood changes and changes in libido were some of the side effects of previous attempts to create a male contraceptive pill. However, women have several contraceptive options, including the pill, implant and intrauterine device (IUD) - many of which also come with unappealing side effects. But because this new male pill does not use hormones, it gives hope for fewer negative side effects in comparison to prior attempts, the early-stage research published in Communications Medicine reveals. The researchers, scientists at drug development company YourChoice Therapeutics, said: 'Since nearly half of all pregnancies in the US and worldwide are unintended, there is a critical need for additional contraceptive options for men and women.' The new drug uses a chemical known as YCT-529, which works by blocking vitamin A metabolites from binding to receptors in the testes, preventing sperm from being produced. Professor Alan Pacey, an andrologist at the University of Manchester, who was not part of the study, told BBC Radio 4's Today programme: "This molecule targets a compound which is related to vitamin A, retinoic acid, and we have known for a long time that this compound is important in how sperm are produced in the testis, making it the perfect target for a male contraceptive pill. 'It is able to inhibit that process without altering the sex hormones, which give men a sex drive.' Previous animal studies have found that using the chemical can create reversible infertility without side effects. In the recent trial, 16 male volunteers aged between 32 and 59 took the drug twice in increasing doses – 10mg, 30mg, 90mg and 180mg – while some took the placebo for comparison. Participants were monitored for 15 days to assess side-effect and hormone levels. The study authors concluded: 'Administration of single oral doses of 10–180 mg YCT-529, fasted, and 30 mg, fed, is well tolerated by healthy male subjects. 'YCT-529 does not demonstrate an adverse cardiac safety profile, or change in haematology, coagulation or serum chemistry parameters, hormone or proinflammatory cytokine levels, sexual drive and mood, and shows good bioavailability (with no clear food effect).' Speaking on the Today programme, Dr Pacey described the findings as an 'exciting step forward' but highlighted the drug has not been tested in a real-world setting to find whether it actually leads to fewer babies. He added: 'It takes three months to produce sperm from start to finish and so if you were to start taking any pill, not just this one, you would need to have the sperm that are currently on the production line to be moved from the system. So, there will be a lag between starting to take the pill and it having its full contraceptive effects.' However, he explained that one of the biggest challenges will be the cost of bringing the new pill to market.
The Guardian
4 hours ago
- The Guardian
Covid cases rising in US as officials plan to restrict booster vaccines
Covid is on the rise again in the US, as children begin returning to school and as officials plan to restrict booster shots. While cases are increasing less quickly than at the start of other surges, it is too soon to tell how big the current late-summer wave could get – and with highly varied immune responses from prior infections and vaccinations, it is difficult to know how severe illness could be, experts said. The risks of a wave are compounded by new vaccine restrictions from the Trump administration. 'If you're vaccinated against Covid-19, you're less likely to get infected,' said Andrew Pekosz, a virologist at Johns Hopkins University. 'But we haven't gotten a lot of people vaccinated for the past few years, and with the current recommendations changing, it's even less likely.' Future waves could become more severe as vaccination lags and immunity drops, Pekosz said. Several key measurements – including wastewater data, test positivity and emergency room visits – indicate a new rise in infections. In the past, Covid has surged about twice a year, usually in the summer and the winter. But the pattern can change, as it does with other respiratory viruses – with late or early starts to the season and curveballs like double peaks. 'Each year has been different, so in some ways, this is more of the same,' said Sam Scarpino, a professor of health sciences at Northeastern University. Cases are increasing or likely increasing in 26 US states, especially in the south and midwest, according to the US Centers for Disease Control and Prevention (CDC). 'In the snapshot that we're seeing right now, increases are happening at a relatively low rate, and that would indicate that we probably aren't going to peak at a very high level. But again, this is early in this summer surge, so we really have to keep monitoring the data and paying attention to what it's telling us,' Pekosz said. The variants currently spreading around the globe have known immune-evasion properties, Scarpino said. 'You can look at the rise that we're seeing, the fact that we know it's an immune-escape variant, and I think we can be pretty confident that there's some kind of wave coming,' Scarpino said. 'Whether it's going to be large or small, I don't think we could really say one way or the other.' But 'the vaccines are still providing some protection,' he said. 'It's never too late to get the booster.' Yet officials softened the recommendation for children on Covid vaccines, and they removed the suggestion entirely for pregnant people, despite the clear benefits of the shot in reducing the risk of severe illness and death during pregnancy. A new, more effective Covid shot from Moderna and the Covid shot from Novavax were approved only for people over 65 or people over the age of 12 with health conditions. The independent advisers to the US Food and Drug Administration (FDA) recommended that vaccine manufacturers once again update booster shots this fall to a more recent variant. Covid boosters are usually recommended for all adults. But this fall, the boosters may be limited to older people and those with health conditions, FDA officials wrote in May. 'So it's a big question mark, going into the fall, is who it's going to be approved for,' Scarpino said. 'If it's not approved, can you still pay out of pocket for it? How much is it going to cost? And then are there going to be supply chain issues?' Health officials have also called for placebo trials for the boosters to judge their benefit to people without pre-existing conditions – but such trials would be unethical and extremely difficult to conduct, experts say. 'Clearly, the guidelines right now are focused on the populations that are more prone to have severe disease and severe outcomes. It's always been good to vaccinate that population,' Pekosz said. But the Trump administration is moving away from the approach of immunizing broad swaths of the population – especially those most likely to get and pass the virus on, like children, he said. 'If you vaccinate broadly, you can reduce the spread of Covid-19 in the population,' Pekosz said. 'The benefit, to me, is very clearly on the side of getting vaccinated.' Some of the pre-existing conditions proposed by FDA officials include asthma, diabetes, depression and physical inactivity. According to that list, 'basically everybody's eligible for one of the vaccines,' Scarpino said. And doctors, including pediatricians, may also prescribe vaccines for off-label use. Yet the more restrictions are placed on vaccination, the harder it is to reach even the people who need it most, Pekosz noted. Antivirals like Paxlovid could also see wider use, the experts said. 'We shouldn't forget about the antivirals,' Pekosz said. 'Those don't seem to be the target of more restrictive use by the CDC or the FDA, so those will be available for people if they do get infected.' A program to make Paxlovid more affordable to those who need it is slated to end in December. 'The benefits of antiviral treatment are very clear with respect to hospitalization and mortality decreases,' Pekosz said. Paxlovid is still highly effective against current variants, Scarpino said. 'There's a whole bunch of good reasons to get it.' Rates of hospitalizations and deaths in recent waves have dropped among adults compared to earlier Covid waves, but the virus remains deadly. An estimated 35,000 to 54,000 people in the US have died of Covid since October. Children continue to see hospitalizations rates from Covid similar to previous years. Covid cases can be less severe because of immunity – from prior infection or from vaccination. 'It's not so much that the virus has become less dangerous, it's that we have immunity, so we fight off the virus more efficiently than we did early in the pandemic,' Pekosz said. That's why vaccinations remain a key part of controlling Covid, he said. Without boosters, people become more susceptible to severe illness and death. Some 23% of adults had received updated Covid boosters as of April. About 5.6% of children aged six months to four years are vaccinated against Covid, and about 15% of children aged five to 17 are vaccinated, according to the CDC. 'Children's cases are always surging, because children don't have much immunity to Covid,' Pekosz said. 'Covid cases are really occurring in children at a very high level right now. It's not nearly as dangerous in children as is in adults, but it still causes a lot of hospitalizations in children.' Hospitalizations and deaths are not the only ways to measure the damage and disruption wrought by Covid. While the Trump administration has not released updated data on long Covid, an estimated 5.3% of all adults in the US said they were currently experiencing long-term Covid symptoms as of September. Even in times of lower transmission, Covid still circulates, with 149 deaths in the week ending June 28, the last week for which the CDC shares full mortality data. 'It's still a little surprising that it's around all year,' said Pekosz. During lull times, 'we're not seeing it disappear completely, like we do with other respiratory viruses.' When it comes to keeping rates of Covid low, 'it's all the same stuff we usually go over,' Pekosz said – getting vaccinated, taking precautions like masking and using air purifiers, and staying home if you're sick. 'But it's just a very different environment these days. When the government doesn't use the science to drive their decision making, you can see the confusion that it puts into the general public.'
