Sunday, August 9, 2009
Por fuera parece una casa normal, con puertas, ventanas o escaleras. Pero en realidad es una vivienda capaz de resistir vientos de hasta 300 kilómetros por hora sin sufrir daños.
Es la casa anti huracanes que esta semana fue presentada en México, y que de acuerdo con sus diseñadores es una alternativa para evitar decenas de muertes por el embate de los ciclones.
El nuevo modelo está hecho de acero cubierto de concreto, y en su construcción fue utilizada tecnología similar a la de algunos de los edificios más altos del mundo, como la Torre 101 de Taipei, según dijo su diseñador, Federico Martínez, en conversación con BBC Mundo.
La casa anti huracanes también resiste inundaciones y avalanchas. Su costo es de unos US$25.000, similar a una vivienda pequeña en México.
"Los ciclones no la destruyen y no podrán matar a las familias", aseguró Martínez.
De acuerdo con datos oficiales, cada año el país enfrenta por lo menos cuatro huracanes de gran intensidad, que causan daños en las costas y montañas de 14 estados.
Cajas de acero
El prototipo fue construido por el Instituto Politécnico Nacional (IPN), una de las universidades públicas más grandes de México, con fondos del Consejo Nacional de Ciencia y Tecnología (Conacyt).
Se trata de varias placas de acero unidas con tornillos y cubiertas con concreto. El conjunto es anclado al suelo para evitar que el viento levante la casa.
También cuentan con un sistema de ventilación especial, pues la mayoría de las casas anti huracanes serían construidas en zonas tropicales.
"Adaptamos unas rejillas en la parte inferior, al ras del suelo, y otras en el techo de manera que el aire circula permanentemente, enfriando la habitación", explicó Martínez.
Las casas miden en promedio 42 metros cuadrados pero pueden ampliarse tanto como sea necesario. Sólo basta unir nuevas placas de acero y concreto para construir otras habitaciones.
Para protegerse de las inundaciones, el IPN creó una variante de la casa anti huracanes que sigue el mismo modelo pero con la diferencia de que se construye sobre pilotes de varios metros de altura.
Con este diseño pueden soportar las crecientes de los ríos o inundaciones prolongadas.
Los prototipos incluyen construcciones de mayor tamaño que podrían funcionar como escuelas gran parte del año, y que se pueden transformar en albergues en la temporada de huracanes, que en México inicia en mayo y concluye en noviembre.
De acuerdo con Federico Martínez, las autoridades mexicanas analizan la posibilidad de construir en serie las casas anti huracanes sobre todo en las áreas consideradas de alto riesgo como las costas del Golfo de México, el Caribe y el sureste del país.
Si los prototipos demuestran ser eficientes, seguros y económicamente rentables, es posible que en el futuro no sólo se construyan en México, sino también en otras partes del mundo.
Este sábado se presentó en La Habana Vieja, Cuba, el "Diccionario de Pensamientos de Fidel Castro", una recopilación de conceptos realizada por el profesor Salomón Susi Sarfati, titular de la Escuela Superior del Partido Comunista Cubano.
"497 entradas con 1978 aforismos que reflejan en su conjunto aspectos fundamentales del pensamiento de Fidel Castro expresados a lo largo de 51 anos", explicó el autor y agregó que se cuenta con un índice temático para una búsqueda rápida.
Se trata de una investigación de los discursos de Fidel Castro, de donde el autor escoge frases que reflejan los criterios del máximo líder de la Revolución Cubana sobre los más variados temas políticos, sociales y económicos.
Varios cientos de personas hacían cola desde temprano en el Palacio del Segundo Cabo, en La Habana Vieja, para poder comprar un ejemplar del Diccionario. La demanda fue tal que se agotaron rápidamente las existencias puestas en venta.
La primera definición que aparece en el Diccionario es la palabra "Acero" acompañada de una frase que dice: "nada que esté erigido sobre pilares de acero podrá caerse jamás", parte de un discurso de Fidel Castro en un congreso infantil en 1991.
Curiosamente, en la palabra "Eficiencia", aparece una frase en la que sostiene: "es imposible en absoluto que los mecanismos y estímulos económicos en el socialismo tengan la eficiencia que tienen en el capitalismo, porque en el capitalismo lo único que funciona es el estimulo y la presión económica a plenitud absoluta".
En el término "Poder" se recuerda que Castro dijo: "!Ah!, pero el poder es el poder. Quizás la lucha más importante que tiene que librar alguien que tenga poder, es la lucha contra sí mismo, la lucha por auto controlarse. Quizás sea una de las cosas más difíciles".
"Los que hablan de democracia deben empezar por saber lo que es democracia. Es el respeto de todas las creencias; es el respeto a la libertad y el derecho de los demás", dice una de sus definiciones, sacada de un discurso pronunciado en 1959.
Un Dios vivo con ideas vigentes
En entrevista a algunos de los cientos de cubanos que hicieron cola desde la mañana frente a las meses de venta del libro, recogimos -como era de esperar- opiniones favorables que resaltaron que las ideas del máximo líder tienen total actualidad.
"Los pensamientos de Fidel son eternos y validos para toda la humanidad. Igual que lo es el pensamiento de José Martí", dijo a la BBC Zenaida Hernández cuando salía en medio del gentío con uno de los libros en la mano.
William Quesadilla, de 25 años nos explicó que "para mí es muy importante tener el libro porque son los pensamientos de una persona con muchas ideas, de una luz muy larga. Su pensamiento es el de Martí, Bolívar y Marx, por eso mantiene vigencia".
"El pensamiento económico de Fidel tiene plena vigencia", afirmó el investigador, economista y diputado Osvaldo Martínez. De los actuales cambios en la política agrícola dijo que "no hay contradicción, se trata de graduaciones dentro de una misma matriz de pensamiento general".
Rita Núñez, de 70 años, contó a la BBC que "fui combatiente y no me pesa porque gracias a la Revolución viví lo que nunca hubiera vivido con otros gobiernos. En nuestro país solo tenemos un Dios, un Dios vivo, que lo ha dado todo y para todos: Fidel".
En el cuento, un cuervo arroja piedras dentro de un cántaro para elevar el nivel del agua para poder beberla. La moraleja es que la necesidad es la madre de las invenciones.
Lo que parece fruto de la imaginación del fabulista resulta coincidir con la realidad: un equipo de científicos de la Universidad de Cambridge y la Universidad Queen Mary de Londres comprobó que los cuervos hacen exactamente lo mismo que en la fábula al presentárseles una situación similar.
Según la investigación, publicada en la revista Current Biology, se puso a un grupo de grajos -aves de la familia de los córvidos- frente a un tubo con agua, en la cual flotaba un gusano. Junto al tubo se colocaron piedras.
Como se ve en el video de arriba, como no llegaban a atrapar el gusano con el pico los grajos comenzaron a meter piedras en el tubo hasta que el nivel de agua subió lo suficiente como para atrapar al gusanillo.
Los más inteligentes
Los pájaros fueron extremadamente precisos y colocaron la cantidad exacta de piedras necesarias para atrapar al gusano. Ni una más, ni una menos.
En otro experimento similar, se les presentó a los grajos la misma situación pero las piedras tenía diferentes tamaños. Como explicó a la BBC el doctor Nathan Emery, de la Universidad Queen Mary de Londres, "los grajos eligieron las piedras más grandes y lograron atrapar al gusano más rápidamente".
Otros estudios anteriores muestran la enorme capacidad de los cuervos para resolver problemas de este tipo.
Los únicos animales capaces de realizar ejercicios similares son los orangutanes. Christopher Bird, coautor del estudio, le dijo a la BBC: "Los córvidos son extremadamente inteligentes, y en muchos casos compiten con los grandes simios en su inteligencia física y capacidad de resolver problemas".
t takes an hour and a half in a light aircraft to reach the Mosquito Coast from the Nicaraguan capital, Managua.
By road it is a journey of almost 20 hours.
You cross 450km (280 miles) of remote terrain; forested mountains and then deserted swampland.
It feels like travelling to another country.
And that is precisely what many of the people who live here say it should be.
For centuries, the Miskito people have made up the majority indigenous population on this bleak, flat coastline. Last April, a group of their elders formally declared independence.
No more, they said, would they pay any heed to the government in Managua. No longer would they pay taxes. Instead their loyalty would be to the "Community Nation of Moskitia".
A flag was designed, and a national anthem composed.
"Every nation has the right to independence," says Oscar Hodgson, a lawyer for the independence movement. "And we are a nation."
His surname, like many in the Miskito community, reveals something of the history of this isolated outpost.
Throughout most of the 18th and 19th Centuries, the Miskitos were allied to the British, whose navy provided them with weapons, and encouraged them to launch raids on neighbouring Spanish bases.
Their land, which stretched from what is now Honduras in the north, almost to Costa Rica in the south, became an informal British protectorate.
But in 1894, by which time the protectors had other priorities, the territory was annexed by Nicaragua.
The current leader of the Miskitos is an affable, avuncular man called Hector Williams. His Miskito title is Wihta Tara, or Great Judge.
"The people asked me to lead them, and that is what I shall do," he says, as he stands in the warm evening sun overlooking the Caribbean sea.
The relationship between the Miskito people and the government in Managua has never been easy.
After the Sandinista revolution led by Daniel Ortega succeeded in 1979, many Miskitos were quick to join the US-backed counter-revolutionaries or "contras".
Some found the Marxist route they saw President Ortega following as offensive to their religion and their culture.
But the latest catalyst for conflict is not primarily ideological, but economic.
Specifically, it is the price of lobster.
Miskitos have traditionally been employed as hired hands on government-licensed lobster fishing vessels along this coast.
In the last few months, their wages have been cut. The foreign owners of the boats say that they are reacting to the fall in global markets. The Miskitos suspect a rip-off.
"They pay us less and take a bigger cut," says Mario, a lobster diver. He is standing on the scrubbed wooden deck of the Puerto Cabezas port. Behind him are dozens of boats, all in harbour because business is so bad.
"The lobsters should be ours anyway," he adds.
His discontent, and that of hundreds of divers like him, has been seized upon by the Miskito leadership in their latest bid for independence.
The movement appears to have been given a sense of urgency by the fact that two oil drilling concessions have recently been granted off the coastline.
"They take everything from us, and give nothing back," says Oscar Hodgson.
But the mayor of Puerto Cabezas, Guillermo Espinozo, doubts that the independence movement is as popular as it claims.
"It's all connected with the lack of employment," he says. "If I called these people...and offered them jobs, they would come here and work. They would soon stop talking about independence."
Puerto Cabezas is the poorest corner of Nicaragua. Unemployment stands at around 80%.
In its municipal square, grown men sit aimlessly on the children's swings. On a concrete block across the road there is a fading poster calling for Daniel Ortega's election in 2006. It is covered with insulting graffiti.
A few blocks away hundreds of Miskitos gather at the indigenous people's community centre.
"Long live independence," they chant. And they sing their national anthem.
During the 2008 US presidential election, rumours began to circulate on the internet that Barack Obama had not been born in the United States, and was therefore not eligible for the presidency.
Mr Obama's campaign provided plenty of evidence to rebut the claims, including the candidate's birth certificate, but the chatter has not died down, and some people have even launched lawsuits to question Mr Obama's eligibility.
With Mr Obama now installed in the White House, the number of Americans who believe - despite all evidence to the contrary - that he is not eligible to be president, and that his birth certificate is a forgery appears to be growing.
And "birthers" - as those who doubt Mr Obama's eligibility for the presidency are pejoratively known - have started making their presence felt within the conservative movement.
What allegations are being made about Mr Obama?
The principal allegation is that Barack Obama was not born in the United States, and that he is therefore ineligible to be president, according to the US constitution, which states that "no person except a natural born citizen... shall be eligible to the office of President".
It is further alleged that any documents purporting to prove Mr Obama's eligibility are either insufficient or fraudulent.
Some of those challenging Mr Obama's eligibility allege that he was actually born in Kenya, or that he adopted Indonesian citizenship as an infant.
What documents have been presented proving Mr Obama's eligibility?
In June 2008, the Obama campaign - in an attempt to disprove another set of internet rumours that Mr Obama's middle name was Muhammad - made public his birth certificate.
The document - a Certification of Live Birth - indicated that Mr Obama had been born at 7.24pm on 4 August 1961, in Honolulu, Hawaii.
Researchers have also dug up birth notices for Mr Obama printed in the Honolulu Advertiser and the Honolulu Star-Bulletin in 1961.
The newspapers received information about births from Hawaii's Department of Health.
Did the documents stop the rumours?
No. When Mr Obama's Certification of Live Birth was published, as a scanned document on the Obama campaign's website, some people began to question its authenticity.
It was alleged in blog posts, chain emails and internet forums that the document did not have an official stamp or seal and that it lacked an official signature. Some even suggested that the document had been faked using picture-altering software.
Was there any substance to these allegations?
No. Representatives from the Annenberg Public Policy Center's Political Fact Check project examined the hard copy of the document and verified that it did in fact bear an official seal, and had been signed by Hawaii state registrar Alvin T Onaka (using a signature stamp). Both the seal and the signature were on the (unscanned) reverse of the document.
Did that put the rumours to bed?
No. Although most people accepted the authenticity of the birth certificate, a new allegation emerged.
The document released by the Obama camp was a Certification of Live Birth, freshly created in 2007 by Hawaiian officials at the request of the Obama campaign, based on Hawaii's computerised records, not the original hand-written long-form "Certificate of Live Birth", created by the hospital at the time of Mr Obama's birth.
A Certificate of Live Birth contains more information, including the hospital name, and the name of the attending physician.
Campaigners alleged that Hawaiian law permits the issuance of Certifications of Live Births to people born abroad, and began calling on the Obama campaign to release the long-form Certificate of Live Birth, which they said would answer all of their questions.
WorldNetDaily, a website that has been at the forefront of the campaign to probe Mr Obama's presidential eligibility, has drawn up a petition calling on Mr Obama to release the document.
Has the Certificate of Live Birth been released?
It has not. But Dr Chiyome Fukino, Director of the Hawaii Department of Health, has released a statement confirming that she has "seen the original vital records maintained on file by the Hawaii State Department of Health verifying Barack Hussein Obama was born in Hawaii and is a natural-born American citizen".
And, as Janice Okubo, director of communications for the Hawaii Department of Health, explains, no-one who was born abroad could get a certificate saying they were born in Hawaii.
"If you were born in Bali, for example," Ms Okubo told the Washington Independent, "you could get a certificate from the state of Hawaii saying you were born in Bali. You could not get a certificate saying you were born in Honolulu. The state has to verify a fact like that for it to appear on the certificate."
Have campaigners attempted to air their concerns in the courts?
A number of lawsuits have been filed by people who question Mr Obama's eligibility, but all of them have been dismissed at the earliest stages.
In July, Stefan Cook, a major in the US Army Reserve who was due to be deployed to Afghanistan, filed a lawsuit seeking to block his deployment, on the grounds that his orders were invalid, because President Obama was ineligible to serve as commander-in-chief. His case was dismissed.
Have any mainstream politicians endorsed the campaigners' views?
Most Republicans have rejected the claims, but Alan Keyes, a former Republican presidential candidate, has filed a lawsuit questioning Mr Obama's eligibility, and Republican Senator James Inhofe has said he does not "discourage" the movement.
The Argentine Football Association has announced that the start of the country's football season will be postponed because of clubs' growing debt.
The premiership - Primera A - was due to start on 14 August.
Last week, AFA President Julio Grondona postponed all the second division and regional games, saying the delay would give the clubs time to find millions of dollars in back-pay for players.
Twenty-one clubs are struggling with debt, including seven in the first division. The country's most famous teams - Boca Juniors and River Plate - are among the clubs affected.
Mr Grondona said that part of the reason for the clubs' debt problems was the global economic downturn.
European clubs - where many of the best Argentine footballers play - have been reducing their purchases of Argentine players because of the recession.
"The recession in Europe is making it very difficult for Argentine clubs, who very much depend on the sale of players," Mr Grondona told reporters last week.
"Clubs aren't getting what they usually get."
But many analysts in Argentina say that the real problem is the clubs' gross mismanagement of finances.
And Mr Grondona admits that the AFA may also have played a part in the financial chaos by bailing out the clubs in the past when they got into financial difficulties.
"[The clubs'] resources are now very low. Perhaps I was overly generous in the past, I gave them money, or rather AFA did, and this has given them the chance to spend even more," he said.
Critics of Mr Grondona argue that the AFA is also partly to blame for the current crisis by failing to help clubs organise themselves efficiently.
"Here club directors change constantly, they are elected and re-elected from within the club by their members," says Raul Gamez, former president of Club Atletico Velez Sarsfield in Buenos Aires.
The AFA should represent club interests rather than its own, says Mr Gamez, particularly in the sphere of television rights.
"The AFA should be fighting for clubs to get the largest share of television rights money and not keep it for itself," he says.
For their part, Mr Grondona and the AFA appear to be working hard to obtain a bigger share of TV rights.
Speaking to reporters on Tuesday night, an AFA spokesman said that the postponement of the football would allow more time for negotiations to continue between the AFA and the authorities that manage TV rights.
The rights are not due to be reviewed until 2014.
Sports analysts say the growing role of the "Barra Bravas" - violent groups of fans who demand money from the clubs in return for their unconditional support - is another factor contributing to the clubs' debt problems.
The "Barra Bravas" have been driving many ordinary supporters away from the stadiums, reducing clubs' incomes.
Eric Verschoor is a life-long fan and member of Club Atletico Velez Sarsfield. He has seen the "Barra Bravas" threatening directors and players with violence, getting involved in player transfer deals and ticket touting.
"Since everything has turned into a business, there are lots of power struggles and increasing violent deaths within the 'Barra Bravas'," he said.
"Innocent people get caught in the middle, so families no longer go to football matches."
Raul Gamez thinks that the AFA should deal with the violence within football, not the clubs.
"We've had 40 years of gradually increasing violence within Argentine football, and it's an extremely complex social issue," he says.
"The AFA should pay more attention to this."
By cancelling the Argentinians' beloved football a week before the main championship is due to begin, it seems clear that the AFA is trying to put pressure on the authorities responsible for TV rights to pass over more money to the clubs.
But it is also putting pressure on the clubs themselves to clean up their act and stay within their budgets.
Analysts say this may mean - in the short term - clubs buying younger, cheaper players and making lower salary deals.
In a light swipe at players' salaries, Mr Grondona suggested they could handle pay cuts easily since they were paid in dollars, giving them a very favourable exchange rate against the Argentine peso.
"Here players ask for dollars but live in Argentina using pesos," he explained.
As leaders from the US, Canada and Mexico gather for a summit, the BBC's Stephen Gibbs travels to Nuevo Laredo to meet Mexican truck drivers at the heart of a cross-border dispute with their powerful neighbour to the north.
Israel Camarillo kisses the wooden crucifix hanging from his rear view mirror, crosses himself, and edges his 18-wheeler juggernaut onto Highway 85.
He has been driving 18 hours, without a significant break, from Mexico City.
The sun is rising over the parched scrubland in front of us. We are on the final stretch. Nuevo Laredo, the busiest land frontier in Latin America, is 200km away.
The road is nearly empty.
The few other trucks on the road are, like us, heading North, to the United States, and ultimately, American consumers.
Not long ago that market appeared insatiable. Now it seems on a crash diet.
And Israel knows it.
"I used to make this round trip eight times a month," he says.
"Now I am lucky if I go there and back twice."
The Mexican economy, the 12th largest in the world, is in the midst of what might be its worst recession since the 1930s. And it is almost entirely due to the collapse in US demand for its exports.
Some 80% of Mexican exports go to the US.
Over the last 12 months, many US companies, which have assembly plants in Mexico, have drastically reduced, or even stopped, their production runs.
Nowhere is that more obvious than at the Laredo border crossing.
Two years ago, a line of parked trucks stretching 14km was a regular sight at the approach to the frontier.
Last week, you could cross from one side to the other in less than 20 minutes.
Israel has to pull over before he reaches the border. US transport regulations prevent him from taking his cargo of Venetian blinds to its final destination in Los Angeles.
So another, specially licensed, Mexican company will collect his trailer and take it across the World Trade Bridge which separates the two countries.
It will then be handed over to an American haulage company for the final leg of the journey to California.
"It makes no sense at all," says Israel as, finally, he thinks about getting some sleep.
The issue of cross-border trucking remains a sore point between the governments of the US and Mexico.
According to the 1994 North American Free Trade Agreement (Nafta), Mexican trucks should be able to operate in the United States, as US trucks and Canadian trucks already do in Mexico.
But last March, the US Congress withdrew funding for an already delayed trial scheme to allow the trucks in.
Mexico retaliated by imposing tariffs on $2.4bn worth of American imports - from California grapes to Oregon French fries.
'Road to unemployment'
Those in favour of the ban, including the powerful US Teamsters labour union, say Mexico has failed to comply with basic safety standards regarding its trucks and drivers.
Those against the move, including the Mexican government and American trade groups, say the dispute is costing businesses hundreds of millions of dollars, and is based upon protectionism.
The dispute will likely be raised by President Calderon in his meetings with President Obama in Guadalajara.
But some believe it is a side issue to a far more urgent crisis.
"We don't want to work on the other side of the border anyway," says Luis Moreno Sesma, General Manager in Nuevo Laredo of Canacar, the Mexican truck owners' Association.
He says the US authorities appear biased against Mexican drivers.
"They are waiting for us like wolves hunting baby deer," he says.
Both governments, he says, should do more to help legitimate trade, and specifically reduce fuel costs of transport.
"Cargo has fallen by 50%. If the economy of the United States does not recover quickly the consequences for us will be disastrous. We are on the road to mass unemployment."
The Venezuelan President, Hugo Chavez, has accused Colombia of carrying out a military incursion into Venezuela.
Mr Chavez said Colombian soldiers had recently been seen crossing the Orinoco river, which forms part of the border, and entering Venezuelan territory.
He said the alleged incursion was a "provocation" by Colombia's government.
The accusations came shortly before a summit of South American leaders is due to discuss a Colombian proposal to allow US troops access to its bases.
Mr Chavez has been embroiled in a diplomatic row with his Colombian counterpart, Alvaro Uribe, ever since news of the plan emerged.
During his weekly TV show on Sunday, President Chavez ordered his troops to get on a war footing along the border with Colombia.
"The threat against us is growing," he said. "I call on the people and the armed forces - let's go, ready for combat!"
He said Colombian soldiers had "crossed the Orinoco River in a boat and entered Venezuelan territory" and that when Venezuelan troops arrived, they had gone.
"This is a provocation by the government of Uribe," he said. "The Yankees have started to command Colombian military forces."
Venezuela's foreign ministry would file a formal complaint, he added, warning that its military would "respond if there's an attack".
Mr Chavez said he would use this week's summit of the Union of South American Nations (Unasur) in Ecuador, to urge his allies in the region to pressure President Uribe to reconsider plans to increase the US military presence.
So far, only Bolivia and Ecuador have condemned the plan, while other countries like Chile and Brazil have said they will respect whatever decision Colombia takes.
Ecuadorian President Rafael Correa, who has already announced he would not be renewing the lease of the current US base in Ecuador, said he was concerned about an increase in military activity across the border his country shares with Colombia.
Mr Correa broke off relations with Colombia in March last year when Colombian troops hunting down members of the left-wing Revolutionary Armed Forces of Colombia (Farc) killed 19 of them in Ecuadorian territory.
"We cannot ignore this threat," Mr Chavez said.
The Venezuelan leader has said he is concerned that the seven Colombian bases could become a new Guantanamo, or an enclave of US influence, like Israel.
Mr Uribe has said the increased US military presence will help Colombia in the fight against drugs trafficking and left-wing rebel groups. He also says US law would only permit a maximum of 1,400 troops and civilian contractors to be based there.
Correspondents say this is not the first time tensions have risen between the Venezuela and Colombian presidents.
Last year, a war of words culminated in the Venezuelans despatching tanks and heavy armour to the border.
The humble raindrop may have played an important role in the evolution of flowers, scientists in China have discovered.
A study of 80 species has revealed that flowers evolve different shapes and structures in part to prevent their pollen getting wet.
Other flowers get round the problem by evolving waterproof pollen.
The finding may help explain why so many species in rainy areas either have droopy flowers or close their petals.
Many researchers, including Charles Darwin, have speculated that flowers may have evolved certain traits or structures to protect themselves against the damaging effects of rain, which can wash away pollen grains and dilute nectar.
But few have experimentally tested the idea.
So Yun-Yun Mao and Shuang-Quan Huang of Wuhan University in China decided to do just that by studying the response to rain and water of 80 species of flower living locally around the University's campus and in the nearby Wuhan Botanical Garden.
"Animals as well as ourselves like to be sheltered when it rains. We were wondering how flowers reduce rain effects on pollen grains, given that plants are immobile," says Huang.
Firstly, they recorded how the flowers of each species respond to rainfall, including whether the pollen becomes wetted or washed away and whether the flower moves or closed its petals.
They also measured the effect of rain on pollen performance, by determining how long pollen produced by each species remains viable in water.
What they found confirmed a strong link between rainfall and flower design, the researchers report in the New Phytologist.
For example, of the 80 species studied 20 produce flowers that completely protect their pollen. As a result, none of these 'waterproof' flowers produce pollen that is resistant to water.
That supports the idea that the flowers have evolved certain structures that can keep their pollen dry and viable and prevent it being washed away before it can be picked up by pollinators.
"Some plants shelter their pollen grains through a change in floral orientation or closing their corolla on rainy days," explains Huang. "For example, tulip flowers close their petals rapidly when rains come."
Others have flowers that droop downward, while Araceae species have outlets in the base of the flower that let water quickly drain away.
But 44 species expose their pollen completely, giving it no protection. Of these species, 13 produce pollen that is highly resistant to water, suggesting they have evolved an alternative way to deal with the rain.
"We were surprised that some plants without pollen protection structures develop water resistant pollen," says Huang.
"The finding of a high proportion of resistant pollen in no-protection species suggests that selection by rain contact favours pollen resistance to water."
Previous research has also suggested that places which have high levels of rain are home to a higher than normal proportion of flowers that nod downward, droop or are able to close their petals.
Mao and Huang hope to investigate this further, and also whether flowers also protect their nectar from the rain.
Conservationists say they are delighted at the news that one of the world's most endangered birds has twice been successfully bred in India.
Two slender billed vultures, which experts say are rarer and more endangered than the tiger, are being reared in Haryana and West Bengal.
Officials say that the chicks were born separately are both in good health.
It is believed the vultures' catastrophic decline has been driven by veterinary medicines.
A decade ago, vultures could be counted in their millions in the wild in India.
But now experts estimate there are only around a 1,000 slender-billed vultures left, with similar declines in other species.
They say it is a a population catastrophe exacerbated by medicine.
A veterinary drug called Diclofenac is fatal to the vultures that feed off the livestock carcasses.
Although it has been banned since 2006, experts say it is still in use.
The BBC's environment correspondent Sarah Mukherjee says that the dramatic decline of vultures has had several effects including an increase in rabies-carrying feral dogs that feed on the carrion the vultures once ate.
The Parsi community in Mumbai (Bombay), who leave their dead to be consumed by vultures, have had to find alternative methods following the dramatic decline of the birds.
The Birdlife International campaigning group says that while the captive births are good news, urgent action is still needed to save vultures from extinction in the wild.
"With extinction in the wild likely in the next 10 years, we do not have a moment to waste. The more vultures that we can bring into captivity means a better chance of survival for these rapidly-declining species," Birdlife International spokesman Chris Bowden said.
"Birds can only be saved from extinction through banning the retail sale of Diclofenac, promotion of the safe alternative, Meloxicam, and the capture of more birds for the breeding programme."
Venomous sea snakes use skin markings and movement to fool predators into thinking their tail is a second head, according to a study.
Scientists found that the yellow-lipped sea krait twists its tail, giving the illusion of having two heads and a double load of deadly venom.
The team published their work in the journal Marine Ecology.
They believe this two-headed mimicry has evolved to protect the sea snake from attack while it searches for prey.
Despite being extremely venomous, the snakes are vulnerable to a number of predators, including larger fish, sharks and birds.
Arne Rasmussen, from the Royal Danish Academy of Fine Arts' School of Conservation in Copenhagen, Denmark, led the study.
He and his team studied the snakes whilst diving off the coast of Bunaken Island in Indonesia.
They followed the kraits as they were swimming between corals and crevices hunting for food.
Dr Rasmussen noticed the two-headed illusion when he spotted one snake with its head apparently facing him while it probed the coral with its tail.
The snake's second head then emerged from the coral and he realised that the first head he had seen was actually a tail.
Dr Rasmussen and his colleagues then examined almost 100 sea kraits from three major museum collections in Paris, Berlin and Copenhagen, while also monitoring the behaviour of the wild snakes during an expedition to the Solomon Islands.
This research confirmed that each sea krait species had a distinctive colouration pattern - a bright yellow horseshoe marking on the tip of both the head and the tail, and similar patterns of black markings.
"This may increase the chances of (the snakes) surviving predator attack by exposing a less 'vital' body part," explained Dr Rasmussen.
"But more importantly it may deter attack in the first place if [predators] perceive the tail as the venomous snake's head."
Drinking beetroot juice boosts stamina and could help people exercise for up to 16% longer, a UK study suggests.
A University of Exeter team found nitrate contained in the vegetable leads to a reduction in oxygen uptake - making exercise less tiring.
The small Journal of Applied Physiology study suggests the effect is greater than that which can be achieved by regular training.
Beetroot juice has previously been shown to reduce blood pressure.
The researchers believe their findings could help people with cardiovascular, respiratory or metabolic diseases - and endurance athletes.
They focused on eight men aged 19-38, who were given 500ml per day of organic beetroot juice for six consecutive days before completing a series of tests, involving cycling on an exercise bike.
On another occasion, they were given a placebo of blackcurrant cordial for six consecutive days before completing the same cycling tests.
After drinking beetroot juice the group was able to cycle for an average of 11.25 minutes - 92 seconds longer than when they were given the placebo.
This would translate into an approximate 2% reduction in the time taken to cover a set distance.
The group that had consumed the beetroot juice also had lower resting blood pressure.
The researchers are not yet sure of the exact mechanism that causes the nitrate in the beetroot juice to boost stamina.
However, they suspect it could be a result of the nitrate turning into nitric oxide in the body, reducing how much oxygen is burned up by exercise.
Study researcher Professor Andy Jones - an adviser to top UK athlete Paula Radcliffe - said: "We were amazed by the effects of beetroot juice on oxygen uptake because these effects cannot be achieved by any other known means, including training.
"I am sure professional and amateur athletes will be interested in the results of this research.
"I am also keen to explore the relevance of the findings to those people who suffer from poor fitness and may be able to use dietary supplements to help them go about their daily lives."
Professor John Brewer, an expert on sports science at the University of Bedfordshire, said: "These findings are potentially exciting for many people involved in sport and exercise, but will almost certainly require further more extensive studies before the exact benefits and mechanisms are understood.
"We must also remember that exercise and training and a sensible diet will always remain as the essential ingredients for a balanced and healthy lifestyle."
Dr Simon Marshall, of the University of San Diego, has carried out work on exercise and health.
He said much more work was needed involving many more subjects to draw firm conclusions.
"Certainly, a diet high in nitrate-rich fruits and vegetables is good for your heart health and this study provides further evidence of this."
ethane on Mars is being produced and destroyed far faster than on Earth, according to analysis of recent data.
Scientists in Paris used a computer climate model for the Red Planet to simulate observations made from Earth.
It shows the gas is unevenly distributed in the Martian atmosphere and changes with the seasons.
The presence of methane on Mars is intriguing because its origin could either be life or geological activity - including volcanism.
Writing in the journal Nature, Franck Lefevre and Francois Forget from the Universite Pierre et Marie Curie in Paris describe how they used a computer model of the Martian climate to reconstruct observations made by a US team.
Dr Lefevre says the chemistry of the Martian atmosphere is still a mystery.
He told BBC News: "We put the dynamics and chemistry as we know it in the model and tried to match the measurements, to reproduce the uneven distribution they saw from Earth."
"The problem is if we just take into account the photochemistry as we know it on Earth and if we put it in the model, then we cannot reproduce the model and that was a surprise."
"The current chemistry as we know it is not consistent with the measurements of methane on Mars."
"There is something else going on, something that lowers the methane lifetime by a factor of 600. So if the measurements are correct, we must be missing something quite important."
Dr Lefevre says the work shows that if there is a much faster loss for methane on Mars there must also be a much stronger production of methane.
But he urges caution: "It's a real challenge to measure methane on Mars from Earth and we've got only one example of this uneven distribution."
The results the French team used were published in January this year in the journal Science. They were gathered by an American team using a technique called infrared spectroscopy at three different ground-based telescopes to monitor about 90% of the planet's surface.
In 2003 "plumes" of methane were identified. At one point, the primary plume of methane contained an estimated 19,000 tonnes of the gas.
Dr Michael Mumma, director of Nasa's Goddard Center for Astrobiology and lead author on the previous paper, told BBC News it was vital to understand how methane was destroyed on Mars and to explain how so much of the gas is produced and destroyed so quickly on the Red Planet.
Dr Mumma does not rule out a biological explanation for the phenomenon but says it is possible that geology alone could be responsible.
If the methane is produced by geological activity, it could either originate from active Martian volcanoes or from a process called serpentinisation.
The latter process occurs at low temperatures when rocks rich in the minerals olivine and pyroxene react chemically with water, releasing methane.
In December, Dr Mumma's team will begin another study of the Martian surface using the new technique of adaptive optics at the European Southern Observatory's Very Large Telescope (VLT) in Chile. They hope to replicate their earlier results.
Dr Lefevre says that if the variations are confirmed it would mean the Martian surface is very hostile for organics. But this would not necessarily exclude the possibility that life or the remnants of past life persist below ground, where conditions could be more benign.
Nasa is due to launch a $2.3bn nuclear-powered rover known as Mars Science Laboratory (also called "Curiosity") to the planet in 2011.
Under one possible scenario, the European and US space agencies would then send a European orbiter to the Red Planet in 2016 to track down the sources of methane.
A subsequent 2018 launch opportunity would be taken by the European ExoMars rover, launching on a US Atlas rocket. The proposal currently being discussed is that ExoMars should be joined by a slightly smaller rover in the class of the US Spirit and Opportunity vehicles that are on the surface today.
ExoMars and its smaller cousin could be targeted at the Methane sources identified by the 2016 orbiter.
A virtual reality exhibit is giving visitors the extreme ranges of sight and hearing that many animals have.
The so-called "immersive" exhibit shows what it might be like to see with birds' ultraviolet vision or hear with whales' ultra-low frequency hearing.
The researchers say the project aims to demonstrate for the public all the sensing ranges animals experience that are described in scientific literature.
The exhibit is on display at the annual Siggraph conference in New Orleans, US.
The light that humans can see and sounds they can hear are just a small sliver of the total range of those experienced by animals.
Many creatures can both make and perceive sounds at higher and lower ranges than we can hear - dogs' perception of ultrasound is a well-known example.
Several animal species are known to be able to perceive light at extreme ranges; birds can see ultraviolet light and their plumage is often highly reflective in this range.
Predators such as rattlesnakes, on the other hand, are sensitive to infrared light, seeing the "heat" given off by their prey.
Carol LaFayette of Texas A&M University's visualisation department and her team wanted to make those senses available to the public.
"If you were walking through the woods and you had the ability to see in ultraviolet, for instance, things like birds or fungi might stand out in very colourful ways," she told BBC News.
"These species aren't very exotic, they're all over the place.
"There is a wealth of information out there in scientific research that is difficult to access and present. Our project makes these fascinating stories accessible to a wider range of people."
The team consulted a number of researchers, gathering together a candidate list of species and even some infra- and ultrasound recordings of animals in the wild.
The system comprises five large projection screens designed in a semicircle.
The virtual reality scene is based loosely on Cocos Island, west of Costa Rica, and visitors to the exhibit can wander through the island's forests or swim in its tropical waters, navigating with the aid of a modified Nintendo Wii game controller.
They can switch between ranges of sounds or sights that they might see.
An ultraviolet setting paints a picture rich with both normal colour and reflections we can't normally see. Visualisation expert Fred Parke has designed the system such that it corrects for perspective as users navigate the space. The programme allows visitors to hear the infrasound vocalisations of whales or the ultrasound clicks of tiger moths.
The effect, with the aid of surround-system built into the exhibit, is a sense of total immersion in the environment, the researchers said.
The sounds can be simply scaled in terms of frequency to a band that humans can hear; "seeing" in ultraviolet, however is a little more difficult. Colours must be assigned arbitrarily to different wavelengths because we simply can't "translate" what it looks like to animals.
The researchers are working to integrate infrared vision into the exhibit, and are considering how to tackle sensory modes that humans don't even have - such as sharks' ability to sense electric fields.
"There are things that we can scale, that we can understand because they are things that we can see or hear - then there are things we don't even know how they can be sensed. That's a really fascinating area," Ms LaFayette said.
The team hopes the idea takes root and imagines the potential for a "live feed" of audio and video from corners of the globe both near and far. Subscriptions to a real-time experience could pay for the purchase of land for wildlife, they said.
"The immersive system ties interest in the environment to knowledge gained through scientific research," Ms LaFayette explained.
"We hope this will generate greater interest in what's out there in one's own back yard."
Scientists have shown just how mind-bogglingly complex are the genetics underpinning the development of cancer.
For the second time a team from Washington University has decoded the complete DNA of a patient with a form of leukaemia.
But the suite of key genetic mutations they found were completely different from those uncovered following analysis of their first patient last year.
The study appears in the New England Journal of Medicine.
What we find may lead us to completely restructure the way we define tumour types.
The latest study does reveal some potentially significant findings.
One of the new mutations found in the second patient was also found in samples taken from 15 other patients with the same disease, acute myeloid leukaemia (AML).
The same mutation is also thought to play a role in the development of a type of brain tumour called a glioma.
A second new mutation was also found in another AML patient.
By using a state-of-art gene sequencing technique, the Washington team became the first to decode the entire genome of a cancer patient last year.
Once they have the full menu of DNA from cancer cells, the researchers can compare it with DNA from healthy cells to pinpoint genetic mutations which probably play a key role in the development of the disease.
The hope is that armed with this information scientists will be able to develop new drugs to target cancer.
Much work to do
But lead researcher Dr Elaine Mardis said: "Only by sequencing thousands of cancer genomes are we going to find and make sense of the complex web of genetic mutations and the altered molecular pathways in this disease.
"What we find may lead us to completely restructure the way we define tumour types and subtypes."
Her colleague Dr Timothy Ley said: "Currently, we don't have great information about how patients with this particular subtype of AML will respond to treatment, so most of them are treated similarly up front.
"By defining the mutations that cause AML in different people, we hope to determine which patients need aggressive treatment, and which can be treated effectively with less intense therapies."
The patient in the latest study was a 38-year-old man who had been in remission for three years.
Analysis revealed 64 genetic mutations which were most likely to play a role in cancer development.
Of these 52 were found in long stretches of DNA that do not contain genes, but which potentially affect how and when neighbouring genes become active.
The researchers compared the results with samples from 187 other AML patients.
They found the same mutation linked to brain tumours in 15 samples, making it one of the most common mutations yet linked to AML.
None of the mutations uncovered from analysis of the first patient was subsequently found in any other AML patient.
Dr Jodie Moffat, Cancer Research UK's senior health information officer, said: "It's exciting that these detailed studies to understand the genetic basis of cancer are now possible due to advances in technology.
"The genetic factors involved in leukaemia are particularly complex, so anything new we can learn is very welcome.
"But further research will be needed before scientists can reveal which parts of the genetic puzzle can actually be used to improve the lives of cancer patients."
Whole "chunks of life" are lost in extinction events, as related species vanish together, say scientists.
A study in the journal Science shows that extinctions tend to "cluster" on evolutionary lineages - wiping out species with a common ancestor.
The finding is based on an examination of past extinctions, but could help current conservation efforts.
Researchers say that this phenomenon can result in the loss of an entire branch of the "tree of life".
The message for modern conservation, say the authors, is that some groups are more vulnerable to extinction than others, and the focus should be on the lineages most at risk.
Lead researcher Kaustuv Roy, a biologist from the University of California, San Diego, focused on marine bivalves - including clams, oysters and mussels. The fossil record for these creatures dates back almost 200 million years.
By tracing this documented timeline of evolution and extinction, the team was able to see the effects of "background extinctions" as well as the mass extinctions, such as the one around 65 million years ago during which the dinosaurs finally died out.
It's like a casino of extinctions, with the odds rigged against certain groups
Many species have become extinct during the relatively stable periods between those global calamities.
But even during such quiet periods, the team found that extinctions tended to cluster into evolutionary families - with closely-related species of clams vanishing together more often than would be predicted by chance.
Richard Grenyer, a biologist from Imperial College London, who was not involved in the study, told BBC News that by going "way back into the fossil record" this study provided important evidence of the patterns of extinction.
"Big groups of organisms tend to be similar to one another," he explained. "Look at the large cats for example."
But genetic similarities also mean, said Dr Grenyer, that "a bad effect that affects one of them, will likely affect all of them".
"It's like a casino of extinctions, with the odds rigged against certain groups."
According to this pattern, the study's authors point out, extinctions are likely to eliminate entire branches of the evolutionary tree.
Professor Roy said: "If you have whole lineages more vulnerable than others, then very soon, even with relatively moderate levels of extinction, you start to lose a lot of evolutionary history."
Julie Lockwood, an ecologist from Rutgers University in New Jersey, US, who did not take part in this study, explained that because extinction events "hit certain lineages extremely hard... we lose whole chunks of life."
"There are examples of modern species where the same thing is happening," she told BBC News.
"In seabirds for example, the same drivers - climatic change and habitat loss - are threatening whole groups of species."
Richard Greyner likened this loss to a fire in a library.
"Because whole sections are lost - the whole of the physics section, or all of the romantic fiction, the overall loss is much worse than if you randomly burned every 400th book."
But Dr Grenyer said that this evidence could help to drive more focused, and therefore more effective conservation efforts.
"We can use this information," he said.
"It doesn't make the conservation of individual species any easier, but if we know the sorts of things that affect tigers, we can infer conservation biology about the tiger's close relatives."
Freshwater dolphins living in the Amazon river basin are being attacked and killed by local fishermen.
Conservationists have found a number of boto and tucuxi dolphins that have been struck with machetes and harpoons and left to die.
The fishermen attack the dolphins fearing they are stealing their fish and ruining their fishing gear.
Some of the killings may also be driven by strong cultural taboos that suggest the animals bring bad luck.
The discovery of the dolphins came during a survey designed to monitor the mortality rate of both Amazonian dolphins and manatees conducted by researchers at the Mamirauá Institute for Sustainable Development in Tefe, Brazil.
During the survey, the research team led by Miriam Marmontel and Carolina Loch recovered 18 dead dolphins, six of which were botos (Inia geoffrensis), also known as the Amazon river dolphin or pink river dolphin, and 12 were tucuxi (Sotalia fluviatilis), another species that lives in the Amazon basin that is more closely related to oceanic dolphins.
Three of the dolphins had unusual injuries.
"These lesions were recognisable as marks made by stabbing with machetes and harpoon wounds," says Loch.
The dolphins were found in two adjacent areas.
Both tucuxi carcasses were found floating in Amana Lake within the Amana Sustainable Development Reserve, a protected area, while the dead boto was found floating in the unprotected Tefe Lake.
Both locations are in the northwestern Brazilian state of Amazonas.
Crucially, no parts of the dolphins' bodies had been harvested, the researchers report in the journal Biodiversity and Conservation.
In some areas in the Amazonian basin, particularly in Colombia and Brazil, dolphins are killed for their body parts which are sold.
"The genital organs and eyes of tucuxis and botos are sometimes sold as amulets in popular markets of some Amazonian cities," says Loch.
She also explains that there is a growing trend toward using boto meat and blubber as bait to catch a scavenging catfish called the 'piracatinga' or Calophysus macropterus.
"This practice is possibly widespread in the Brazilian Amazon and may severely threaten [the boto's] conservation," Loch says.
But the three carcasses were unmolested apart from the initial fatal wounds.
That means that fishermen are killing the dolphins simply to eliminate rather than exploit them.
"Aquatic mammals such as whales, dolphins and sea lions are frequently seen as unwanted competitors for fisheries resources," says Loch. "This sense is also widespread in the Amazonian region, especially among fishermen."
Loch's team think the fishermen suspect the dolphins of taking too many fish, both from the river and from their nets, and damaging their fishing gear in the process.
Cultural beliefs, myths and superstitions may also be driving some of the killings.
For example, in some parts of the Amazonian, the boto is traditionally viewed as a mischievous and tempestuous being, both feared and respected.
In extreme cases, it is thought the dolphins transform themselves into handsome men who come ashore and seduce young women, which explains why their reproductive organs are sold as charms.
But while such beliefs sometimes protect the boto and other dolphins from harm, they can also lead people to kill them out of fear or to prevent unexpected teenage pregnancies.
The researchers say the three carcasses suggest that many more Amazonian dolphins are being intentionally killed, and the practice may pose a significant threat to their conservation.
An extensive education program must be started to mitigate the problem, Loch says.
"Environmental education activities with school children are fundamental to avoid these conflicts in the future," she says.
"Amazonian dolphins play an important role in the local culture of Amazonian region, and positive aspects of this influence should be reinforced and encouraged."
"Negative myths and legends linked to undesired pregnancy of women and enchantment of people should be respected as part of their culture, but should be clarified and negative attitudes towards animals should be discouraged."
Pandemic disease is only one aspect of nature that we still don't have the means to fully predict. Like the weather, it is virtually impossible to foresee with any certainty beyond a few days.
You might just as well study how far up a tree crows build their nests in a particular year, or check to see if it rains on St Swithin's Day.
Such are the limitations of science, whether meteorology or virology. The recent H1N1 or swine flu predictions have led to forecasts of 65,000 deaths in the UK - but the truth is, we simply don't know.
Yet in reporting the outbreak, the media broadly falls between two extremes - from alarming scare stories to experts who purport mass vaccination to be "madness, foolhardy and a gamble".
Whatever happens when the pandemic pans out, there will be a substantial third group - the "I told you so" faction. Pandemic disease remains a critical test of the extent of what we do and don't know.
Pandemics: A Horizon Guide shows how science and the media have grappled with widespread disease, reporting its failures and championing success.
I have enormous faith in science - one of the high points in virology, if not the discipline's crowning achievement, was the eradication of smallpox from the world.
It was only one of many viruses that caused worldwide disease outbreaks but the dreadful suffering it caused made it an obvious target.
Understandably, once smallpox was eradicated some of the scientific community may have begun to believe that they could perhaps conquer all pandemic disease given time.
But in retrospect, smallpox was the ideal candidate for eradication.
The variola virus which caused the disease only infected humans, therefore giving it no natural hiding place such as mosquitoes, birds or mice.
And unlike many other viruses, it didn't mutate readily. This meant it couldn't adapt quickly enough to avoid our defences once we were immunised.
Unfortunately not all pandemics or pathogens are alike. Each is unique and poses its own challenges to science.
Malaria has been banished from Italy, the USA, the UK, and Poland (where it was endemic until the 50s), and is now predominantly a disease of the tropical poor.
However, it still stubbornly resists any further attempts to eradicate it.
With scientific knowledge gained over the last 30 years, HIV has been shown to be a relatively difficult virus to contract and easily avoided with simple interventions.
For example, free condoms, needle banks, education, and behavioural changes.
Yet still it kills in the region of three million people each year (approx one person every 10 or 15 seconds).
And of course there is the most capricious of pathogens: influenza.
In 1918 an outbreak of H1N1 influenza virus killed somewhere between 22 and 100 million people.
However, when a broadly similar H1N1 strain emerged in the US in 1976 only one person died, although it did cause panic across the nation.
I would like to think that we can learn from history. So after making the Horizon programme, which looks at the history of pandemics as covered by TV over the last half century, there are some obvious lessons to be learned.
I think that the take-home message is that pandemics are to be feared and respected, but most importantly that they are incredibly difficult to predict.
Maybe science will have a pretty good idea of what will happen to the swine flu pandemic in the next few days, but trying to predict beyond a few short weeks is much more challenging - much like the weather forecasts. All we can say in certainty is that H1N1 flu is, and will continue to be, unpredictable.
The influenza virologists, epidemiologists and computer modellers I know are diligent, skillful and inspirational people but they are ultimately up against nature.
I hope that in a few years I can take part in an updated pandemics guide and look at exactly what happened with this pandemic.
Then, with the benefit of hindsight, I might be able to say whether it was a storm in a teacup or whether we did too little too late. And find out who can say with total honesty "I told you so".
Radiotherapy used to treat brain tumours may lead to a decline in mental function many years down the line, say Dutch researchers.
A study of 65 patients, 12 years after they were treated, found those who had radiotherapy were more likely to have problems with memory and attention.
Writing in The Lancet Neurology, the researchers said doctors should hold off using radiotherapy where possible.
One UK expert said doctors were cautious about using radiotherapy.
The patients in the study all had a form of brain tumour called a low-grade glioma - one of the most common types of brain tumour.
In these cases radiotherapy is commonly given after initial surgery to remove the tumour, but there is some debate about whether this should be done immediately or used only if the cancer returns.
It always depends on the patient, but if it is possible to defer radiotherapy, maybe people should
Dr Linda Douw, study leader
It is known that radiation treatment in the brain causes some damage to normal tissue and the study's researchers suspected it could lead to decline in mental function.
A previous study in the same patients done six years after treatment found no difference in aspects like memory, attention and the speed at which people could process information, in those who had received radiotherapy.
But the latest research, carried out more than a decade after original treatment, did find significant variation in the results of several mental tests between those who had had radiotherapy and those who had not.
In all, 53% of patients who had radiotherapy showed decline in brain function compared with 27% of patients who only had surgery.
The most profound differences were in tests to measure attention.
With an average survival of ten years for this type of tumour, the researchers said patients undergoing radiotherapy were at considerable risk of developing problem years down the road.
One option for doctors would be to delay when patients received radiotherapy, reserving it in case the tumour returned, they advised.
But she added that more research was needed and there were trials under way to look at other treatments such as chemotherapy.
In an accompanying article, experts from the Mayo Clinic in Rochester, USA, said it was hard to draw conclusions because radiotherapy had improved since the patients in the study had been treated, but agreed more studies were needed.
Dr Jeremy Rees, a Cancer Research UK scientist at the National Hospital for Neurology and Neurosurgery Honorary said they would usually try to avoid giving radiotherapy to patients with low-grade glioma, unless the tumour was progressing or the patient had epilepsy not controlled on standard medication.
"Surgery is generally a preferred option with chemotherapy or radiotherapy coming into play at a later stage, if the glioma progresses.
"Continued research and increased knowledge about the disease is enabling us to treat it increasingly effectively while reducing side effects."
The government is consulting on how it can ensure that the UK's food supply remains secure in the future.
While the current situation in the UK is good, ministers warn that factors such as climate change and population growth could have an adverse effect.
Producers, supermarkets and consumers are being encouraged to submit their ideas on how a secure food system in the UK should look in 2030.
Some of the findings are expected to be published in the autumn.
As well as launching the consultation process, the Department for Environment, Food and Rural Affairs (Defra) has published a scorecard-style assessment of the current state of the UK's food supply.
"It is to stimulate a debate within the UK on what a food policy should be, and how do we define and look at food security more broadly," said Defra's chief scientific adviser Professor Robert Watson.
"Food is absolutely essential, and over the past few years we did see a food price increase - not only in the UK, but across the globe," he told BBC News.
"We think it is time to have a debate with consumers, farmers, the private sector... on what the food policy should be for the UK.
"We are clearly food secure in the UK today," he observed. "We produce about 60-65% of our own food [and] import about 20% from Europe.
"So the [test] for us will be, as the Earth's climate changes, what will be the challenges not only in the UK but throughout the world?"
Food for the future
Defra's food security assessment focused on six areas, including global availability, UK food chain resilience and household food security.
It assessed the current situation in each area, and the likely situation in 5-10 years time.
One sector that was identified as "very unfavourable" and showed no signs of improving was global fish stocks.
Yet other areas, such as the diversity of the UK's suppliers of fresh fruit and vegetables was deemed "favourable" and set to improve even more.
In July, the Sustainable Development Commission - the government's environmental watchdog - warned that the current food system was failing.
In its report, the commission warned that the current approach was a major source of greenhouse gas emissions, and paid little attention to soil quality and water use.
The report's author, Professor Tim Lang - a member of the UK government's Food Council, said the system had to radically change.
"We are going to have to get used to less choice, and we are going to have to eat differently," he told BBC News.
"For climate change; for water; for energy; for all sorts of reasons our diet is going to change. Consumers are not going to like it, although it is probably going to be healthier and definitely more sustainable.
"So this is a problem for government, it is a problem for food companies, but above all it is a problem for consumers."
Diagram showing UK self-sufficiency for food groups (Image: BBC)
Responding to the Defra publications, the British Retail Consortium said that any strategy had to be centred around consumers.
"Without their buy-in, no plan will work," said food policy director Andrew Opie.
"We do need a sustainable supply chain, but retailers do not need government statements to wake them up to these issues, they are already taking action.
"What we need is joined-up policy with government agreeing what it wants from food across all its departments and agencies."
The future security of food supplies has been the subject of debate on the international stage.
The G8 summit, held in Italy in July, saw the leaders of the world's richest nations pledge $20bn over three years to boost agriculture in developing nations.
The UN Food and Agriculture Organization's (FAO) director-general Jacques Diouf has invited world leaders to attend a food security summit in Rome in November.
Accompanying the invite, Mr Diouf also sent a document to the world's foreign ministers that called for world hunger to be eradicated by 2025, and for "secure, sufficient, safe and nutritious food supplies" to feed a population that is projected to reach 9.2 billion in 2050.
In light of the uncertainties facing future food supply systems, scientists are researching and developing ways to boost food production on increasingly limited arable land.
"The remit of what we are trying to do is to try to get more from the land, making agriculture and horticulture much more efficient," said Dr Chris Atkinson, head of science at East Malling Research, Kent.
"Growing things in a much more engineered way allows research to develop, improving the way that we can produce crops.
The institute's projects include growing strawberries that require only a quarter of the water needed by conventional crops.
Dr Atkinson said these sort of developments could then be adapted and applied to other food crops, boosting productivity.