By David Lawder and Ann Saphir SAN FRANCISCO (Reuters) -U.S. Treasury Secretary Janet Yellen on Monday said negotiations on the

BERLIN (Reuters) -The German economy contracted slightly in the first quarter of 2023 compared with the previous three months, thereby

Researchers have invented a double-sided solar panel capable of generating electricity from the Sun’s energy on both sides. The bifacial solar cell, developed at the US Department of Energy’s National Renewable Energy Laboratory (NREL), harvests reflected sunlight hitting the back of the device, offering an unconventional route to producing higher energy yields for less space and cost. Typical advances to solar cell efficiency rates centre on iterative improvements to the side facing the Sun. This new approach could boost the energy harvesting capabilities of solar panels beyond their theoretical limit. “This perovskite cell can operate very effectively from either side,” said Kai Zhu, a scientist at the Chemistry and Nanoscience Center at NREL who led the research. Current solar cell technologies, which use silicon as the semiconductor material, have an efficiency rate of around 26 per cent – higher than the 23 per cent achieved in lab tests by the front side of the new panel. The back side of the panel, however, achieves an efficiency of about 91-93 per cent of the front, which offers up to 20 per cent more power overall when harvesting reflected sunlight. Perovskite has become a key driver of solar cell advancements in recent years, breaking new efficiency records and providing new pathways to creating next-generation technologies. Earlier this week, researchers unveiled perovskite-based solar cells capable of healing themselves when damaged by radiation in low-Earth orbit. Tandem silicon-perovskite solar cells have achieved lab-measured efficiency of more than 30 per cent, and have a theoretical limit far higher than purely silicon cells. Rapid progress with their development has seen two separate startups announce commercial production of the next-generation panels. Producing the bifacial solar panels would cost more than monofacial modules, however their capacity to produce more power could make them more economically viable over time. The latest research was detailed in a study, titled ‘Highly efficient bifacial single-junction perovskite solar cells’, published in the journal Joule. Read More Scientists invent self-healing solar panels with ‘miracle material’ How tech could turn our homes into renewable energy power stations

The amount of screen time teenagers get is a worry to lots of parents. And, it turns out, the health impacts of being inside and staring at a screen for long periods of time as a young person can have serious impact on physical health further down the line. According to new research, parents should limit the amount of time children spend on social media and video games, after a study found inactive teenagers are more likely to have signs of heart damage as young adults. A child may appear ‘healthy’ but, even children who have a normal weight were still at risk, the study of 766 British youngsters found, after tracking them for 13 years. Academics involved in the research, which is to be published at the ESC Congress in Amsterdam, said that this heart damage could be setting the stage for heart attacks and strokes in later life. So, how can we get teens up and out? 1. Encourage them to destress Teens may take to their screens to distract themselves from day-to-day life, watch TikToks, or aimlessly scroll – which they may see this as a form of relaxation. It might be helpful to frame exercise in the same way for stressed teens. “Young people today are facing many stress factors in their daily lives and exercise can be an important mechanism to cope and overcome such difficulties,” says Dr Triveni Joshi, consultant child and adolescent psychiatrist for Cygnet Health Care. Reiterate the benefits of exercise for their mental wellbeing too. “When you exercise, your body produces dopamine and endorphins in your brain that help you to feel good. Exercise can have a direct impact on improving mental health by reducing anxiety, depression and low mood,” she says. “Plus, exercise can give you a real sense of accomplishment and pride at having achieved a goal, thereby improving self-esteem and confidence.” Celebrate the accomplishment of just getting out and being healthy for positive reinforcement. 2. Suggest things that interest them “There is always an activity which can suit somebody,” says Joshi.”There is a range of opportunities for physical activity such as gardening, walking groups, Zumba, dancing, pilates, or swimming.” Sports like weightlifting and running are big on social media and “can improve confidence levels and tackle low self-esteem.” While being on social media may stop them from getting out, pointing towards creators who promote a healthier lifestyle may help them in the long run. Perhaps they can pair their on-screen interests and favourite creators with physical experiences. “Exercise should always be fun so often it is about finding where their interests lie and incorporating that into a healthy regime,” Joshi explains.3. Talk to them about why they don’t want to exercise There may be a reason why your teen isn’t eager to get up and about you don’t know about, and having an open discussion may help them feel more comfortable, and build a closer bond with you. “With other pressures in their lives they may feel tired and lack the motivation to get active,” Joshi says. “A lot can depend on personality type too. Introverted children may feel shy, embarrassed, or too concerned about judgements to take part in physical activity. It might not pique their interest or they may feel it is something they aren’t skilful at and therefore don’t have the motivation for fear of not being good at something.” Getting to the bottom of why they won’t exercise may help them feel more empowered to do so, particularly if you can relate to one another and take on this challenge together.4. Set a good example So much of our relationship with exercise is rooted in our childhood, so try to “encourage children to be active by setting the right example and being active yourself”, says Joshi. If you complain about exercise and are on your screen all the time, it sends the message that it’s normal. In trying to set a good example, you may find something you love to do together, like a specific yoga class, workout or weekly ParkRun. Read More Charity boss speaks out over ‘traumatic’ encounter with royal aide Ukraine war’s heaviest fight rages in east - follow live What we know so far about Naomi Campbell’s Pretty Little Thing collection Taking adult education classes may lower risk of dementia, study suggests Indiyah Polack: I didn’t want to go on Love Island because of my acne

As Kylian Mbappe's transfer standoff with Paris Saint-Germain continues it remains unclear if the star striker will even be in the squad when PSG begins its title defense at home to Lorient on Saturday

Sean Dyche has been compelled to deliver “the truth” about Demarai Gray after the winger claimed the Everton manager does not respect him. Gray has not played this season, with Dyche claiming the player did not want to train after being linked with moves to Saudi Arabia and Fulham. However, nothing materialised before Friday’s European deadline – Saudi’s is Thursday – but after being left out of the squad again for the 2-2 draw at Sheffield United, Gray took to Instagram to air his grievance, writing: “It’s so difficult to play for someone who doesn’t show you respect as a person.” Dyche has now taken the unusual step of addressing the issue in an interview with club media. “It’s an unfortunate one because I try to keep our business in-house. I think on this occasion, it’s right to reply,” Dyche said. “Demarai made it clear that he felt he was getting a move (away from Everton) and he told us a move was done, which was interesting to hear from a player. “We reminded him of the truth of the fact that no moves are done without this club’s say so. “We look after these players; we look at all the different ways of looking after them: mental and wellbeing is big, the tactics and technical, the physical. “When it comes to a time like that then you go, ‘Well, hang on a minute. You made it clear you didn’t want to train, you didn’t want to be here, and you also said there was a move that was a done deal’. “We said it’s not a done deal because this club is the most important. This club will make decisions on the future of you as players and not the other way around. “I think it’s right to let our fans know that’s the truth.” Read More Charity boss speaks out over ‘traumatic’ encounter with royal aide Ukraine war’s heaviest fight rages in east - follow live

Jordi Alba gave praise to the entire Inter Miami squad after reaching the Leagues Cup final.

(Reuters) -Arizona is closely monitoring the testing and use of self-driving vehicles in the state, its transportation department said on

In the wake of a Supreme Court decision that removes race from the admissions process, colleges are coming under renewed pressure to put an end to legacy preferences, the practice of favoring applicants with family ties to alumni

Tom Brady has retired from the NFL but remains an extremely clickable name. Between his new business ventures and ever-changing likelihood of joining FOX to collect some of that enormous contract, there is much to discuss. So it's no surprise that many jumped on the opportunity to get him in a headline along with Kim Kardashian.

Walmart extended its streak of strong quarterly gains heading into the holiday season as its low-prices continue to attract shoppers looking for deals in a tough economic environment

This week’s new entertainment releases include an album from country pop duo Dan & Shay, the return of Jennifer Aniston and Reese Witherspoon for season three of “The Morning Show” and you can own “Barbie” — for a price