We may be familiar with The Lion in Winter, the title of the 1968 film starring the late Peter O'Toole, but, with Leo on the ascendency, The Lion in Spring would more aptly characterise our evening sky over the coming weeks.
Our chart covers a swath of Britain's mid-southern sky at 22:00 GMT from Gemini and the conspicuous planet Jupiter in the SW to Leo in the SE. Leo's leading star, Regulus, sits in the handle of the Sickle which represents the head and mane of a lion that is facing W and crouching like Sir Edwin Landseer's lions in Trafalgar Square. Just as Deneb is in the tail of Cygnus the Swan in our summer sky, so Denebola, further E, is the tail of Leo.
The star Algieba above Regulus in the Sickle has a fourth magnitude companion less than a Moon's breadth below, while telescopes split the main star into a glorious binary of golden giant stars only 4.6 arcsec apart that take more than 500 years to orbit each other.
By 23:00 GMT at present, and by nightfall in mid-April, Regulus stands halfway up Britain's meridian as Mars blazes close to Spica in Virgo lower down in the SE.
Jupiter is on the meridian, above and to the left of Orion, at nightfall and is above-right of the gibbous moon on Monday, 10 March. It could hardly be better placed for observation, being higher in our night-time sky than at any time in the next 47 years, if only by a few arcminutes. Decent telescopes reveal its cloud-banded disc, currently 41 arcsec wide, while binoculars show up to four of its main moons.
Jupiter, though, will soon tumble westwards to disappear into our summer evening twilight, only to reappear in time for a spectacular conjunction just 0.2° from the even brighter planet Venus in the morning twilight on August 18.
That meeting occurs with both planets on the fringe of the star cluster Praesepe, or Manger, in the dim constellation of Cancer near the centre of our chart. The two fourth magnitude stars that lie slightly E (left) of Praesepe are Asellus Australis and Asellus Borealis, for the southern and northern donkeys that are eating from the manger.
Also known as the Beehive or M44 from its place in Messier's catalogue, Praesepe appears as a third magnitude circular glow to the naked eye, while binoculars reveal its brighter stars. There may be 1,000 stars in total, all some 600 light years away and perhaps 600 million years old. More distant, and very much older at perhaps 4 billion years, is the fainter sixth magnitude cluster M67 1.7° due W of the star Acubens.
As the Moon slides eastwards against the stars, it stands 7° below Praesepe on 12 March and a similar distance below Regulus two days later.Alan Pickup
Study claims technique can predict with 90% accuracy whether people will go on to develop Alzheimer's within three years
Scientists have developed a new blood test that they claim could detect whether or not a person will develop dementia within three years.
Changes in the blood may signify Alzheimer's disease in its earliest stages, researchers found.
A study, published in the journal Nature Medicine, identified 10 molecules in blood could be used to predict with at least 90% accuracy whether people will go on to develop mild cognitive impairment or Alzheimer's.
It is the first research that has been able to show differences in biomarkers in the blood between people with Alzheimer's before the symptoms occur and people who will not go on to develop the condition.
The finding has potential for developing treatment strategies for Alzheimer's at an earlier stage - when therapy would be more effective at slowing or preventing onset of symptoms, the authors said.
Researchers from Georgetown University Medical Centre in the US examined 525 healthy participants aged 70 and over and monitored them for five years.
During the research 28 participants went on to develop the conditions and 46 were diagnosed at the start of the study.
Midway through the research, the authors analysed 53 patients who already had one of the conditions and 53 "cognitively normal" people.
They discovered 10 molecules that appeared to "reveal the breakdown of neural cell membranes in participants who develop symptoms of cognitive impairment or Alzheimer's. They then tested other participants' blood to see whether these biomarkers could predict whether or not they would go on to develop the conditions.
By measuring the presence of 10 compounds the researchers could predict with 90% accuracy people that would go on to suffer from mild cognitive impairment (MCI) or Alzheimer's (AD).
"The lipid panel was able to distinguish with 90% accuracy these two distinct groups: cognitively normal participants who would progress to MCI or AD within two to three years, and those who would remain normal in the near future," said one of the study's authors, Professor Howard Federoff.
"Our novel blood test offers the potential to identify people at risk for progressive cognitive decline and can change how patients, their families and treating physicians plan for and manage the disorder.
"The preclinical state of the disease offers a window of opportunity for timely disease-modifying intervention. Biomarkers such as ours that define this asymptomatic period are critical for successful development and application of these therapeutics.
"We consider our results a major step toward the commercialisation of a preclinical disease biomarker test that could be useful for large-scale screening to identify at-risk individuals.
"We're designing a clinical trial where we'll use this panel to identify people at high risk for Alzheimer's to test a therapeutic agent that might delay or prevent the emergence of the disease."
Dr Simon Ridley, head of research at charity Alzheimer's Research UK, said: "Alzheimer's disease begins to develop long before symptoms such as memory loss appear, but detecting the disease at this pre-symptomatic stage has so far proved difficult.
"More work is needed to confirm these findings, but a blood test to identify people at risk of Alzheimer's would be a real step forward for research."
Dr Doug Brown, director of research and development at the Alzheimer's Society, added: "Having such a test would be an interesting development, but it also throws up ethical considerations.
"If this does develop in the future people must be given a choice about whether they would want to know, and fully understand the implications.
"This research could also give clues on how Alzheimer's disease occurs and warrants further study, but as such a small number of people showed dementia symptoms there need to be larger studies with different populations before it could be turned into a blood test for Alzheimer's disease."
Three years after the worst nuclear accident in a generation, the Japanese prefecture is reporting a rise in the number of children showing cancer symptoms. But is this directly related to the disaster, or is the testing more rigorous?
When doctors found several tiny nodules on his 12-year-old daughter's thyroid gland, Toshiyuki Kamei refused to let parental fear get the better of him. The symptoms are not uncommon, and the probability that they will develop into something more serious is low.
Yet Kamei can be forgiven for occasional moments of doubt: his daughter, Ayako, is one of almost 400,000 children who were living in Fukushima on 11 March 2011 – the start of the world's worst nuclear accident for a quarter of a century.
"As a parent, of course I worry, but my daughter is taking it in her stride," said Kamei, who lives in Iwaki, a city about 40km (25 miles) south of the wrecked Fukushima Daiichi nuclear power plant. "She doesn't tell me if it's on her mind, and I've decided not to ask her about it."
Three years after the plant suffered a triple meltdown that released huge quantities of radiation into the atmosphere, medical authorities in Fukushima prefecture are reporting a significant rise in the number of thyroid cancer cases among local children and young adults.
The results have prompted a bitter debate about the potential effects the meltdown had on the health of hundreds of thousands of children. Either the higher-than-normal rates of thyroid cancer are connected to the nuclear accident, or they are the inevitable result of a testing regime unprecedented in size, and conducted using state-of-the-art medical equipment.
Last month, the number of confirmed and suspected cases of thyroid cancer among people aged 18 or below at the time of the accident rose to 75, compared with 59 at the end of last September. Of the current total, 33 cases have been confirmed as cancer.
Under the guidance of Fukushima Medical University, local health authorities have so far tested 254,000 out of 375,000 Fukushima children and adolescents, who will continue to be screened regularly throughout their lives.
Medical officials in Japan dismissed a link with the nuclear accident, but conceded that the results required further analysis.
"We hope to look for unknown types of gene mutations, other than those known to be associated with the generation of thyroid gland cancer, to study if they could serve as markers for determining if the cancers were induced by radiation," said Shinichi Suzuki, a professor of thyroid gland surgery at the university.
At first sight, the figures give cause for alarm. Thyroid cancer normally affects one to two people per million among 10 to 14-year-olds in Japan, a rate far lower than observed in Fukushima, although tests there apply to people aged up to 18.
Inevitably, parallels have been drawn with the 1986 disaster in Chernobyl. Estimates vary, but according to the UN Committee on the Effects of Atomic Radiation, more than 6,000 cases of thyroid cancer among exposed children and adolescents living in Ukraine, Russia and Belarus had been reported by 2005. There, no attempt was made to prevent children from drinking milk or eating leafy vegetables, leaving them vulnerable to ingesting dangerous amounts of the radionuclide iodine-131, a recognised cause of thyroid cancer.
But experts familiar with both disasters caution against making similarly gloomy predictions for the children of Fukushima. Dillwyn Williams, emeritus professor of pathology at Cambridge University, pointed out that a noticeable increase in thyroid cancers was not observed until three to four years after the Chernobyl accident.
"Much less radioactivity was released from Fukushima than from Chernobyl," he said. "Most of [the Fukushima radiation] was blown over the Pacific Ocean, and thyroid doses in the most-affected areas are low compared to Chernobyl.
"It is very unlikely there will be a large increase in thyroid cancer or any other health problems, apart from anxiety and psychological difficulties. That does not mean the surveillance should stop. There were surprises after Chernobyl and there may be again after Fukushima."
Williams and other experts have attributed the large number of cases to the use of hypersensitive ultrasound, which can detect the tiniest lesions, and the large number of children being tested.
In Fukushima, the first recorded cases of thyroid cancer – whose latent period can be between four or five years to several decades – came just a year after the meltdown. In Chernobyl, it took four years before cancer rates rose.
"The similarity in the public response to both accidents arises from a lack of awareness of the population about the real dangers and risks of radiation exposure," said Prof Konstantin Kotenko, director general of the state research centre at the Federal Medical Biological Agency in Moscow. "After the both accidents the following was observed among the members of the public: fear and negative stereotypes due to exaggeration of the danger of ionising radiation, symptoms of depression and post-traumatic stress. Undoubtedly, these perceptions of radiation have a negative impact on the health of the population, including children."
Gerry Thomas, professor of molecular pathology at Imperial College, London University, blames growing anxiety among Fukushima residents on "pseudo-scientists who can shout louder than real scientists".
"The biggest effect will be psychological – just as it was post-Chernobyl," said Thomas, who insists the rising number of cases is due to comprehensive screening, not radiation. "I still stick with what I have always said: there will not be a single death due to the radiological consequences of this accident."
But scientists have struggled to reach a consensus over the possible health effects of prolonged exposure to relatively low levels of radiation. While the World Health Organisation and other UN agencies praised the Japanese authorities for ordering the swift evacuation of neighbourhoods close to Fukushima Daiichi, their decision soon after to raise the allowable annual radiation exposure limit from one to 20 millisieverts [mSv] put children in danger, said Dr Paul Dorfman of the Energy Institute at University College, London.
"This is inexplicable, since 20mSv is the allowable dose for an adult radiation worker," Dorman said. "Given that infants and children are still in their developmental stage, they should not have been subjected to this dose.
"Unfortunately, what this means is that we may be seeing increased ill health in the future. Not simply gross cancers and possibly heart problems, but also things that are difficult to detect through epidemiology, such as immune problems."
The anxiety felt by parents in Fukushima stems from a widespread lack of trust in the local medical authorities, which have come under government pressure not to cause alarm among residents.
The Japanese government has resisted calls from parents to conduct comparable screenings among children in a region of Japan that was not affected by the disaster. That, radiation experts say, would at least establish whether or not the thyroid cancer spike in Fukushima is out of the ordinary.
"It is such an obvious measure that could be completed in about six months, but the government has done absolutely nothing for three years," said Koichiro Ono, a local kindergarten teacher. "The government is worried that if the results suggest that there is a link, it will ruin its plans to restart nuclear reactors."
As north-east Japan prepares to mark the third anniversary of the disaster, in which almost 20,000 people died – most of them in two prefectures north of Fukushima – the country's leaders are trying to put a positive spin on the recovery effort.
During a recent visit to a Fukushima village where the evacuation order imposed in March 2011 has been partially lifted, prime minister Shinzo Abe congratulated residents on taking a crucial step towards resuming the lives they were forced to put on hold after their homes were irradiated.
Kamei, however, was not impressed. "How can anyone talk about life returning to normal in Fukushima until everything has been done to ensure that people have their health?" he said. "Politicians keep talking about recovery, but that doesn't mean anything to people living around here."Justin McCurry
Beautiful, strange and occasionally alarming pictures from the short list for this year’s Wellcome image awardsSarah Gilbert