Ebola: previsioni.

I modelli utilizzati per prevedere l'evoluzione dell'infezione sono modelli adattivi, il che significa che aggiornano le proprie previsioni a seconda delle 
informazioni che gli giungono.

Inizialmente, si pensava che dopo nove mesi la situazione sarebbe stata sotto controllo, con 20.000 casi d'infezione.

Oggi, non è più così: le previsioni attuali considerano possibili 20,000 nuovi casi in un mese.
Soltanto in Liberia sono considerati possibili centinaia di migliaia di nuovi casi per fine gennaio.

Visto che una terapia medica è ancora inesistente e comunque meno efficace delle misure di supporto e di prevenzione è soprattutto sull'organizzazione di queste ultime che si deve porre attenzione.
Al momento, si considerano possibili 1.4 milioni di casi infetti totali per la fine di Gennaio 2015.


Ebola could infect more than 1.4 million people by end of January 2015 

The Ebola epidemic could claim hundreds of thousands of lives and infect more than 1.4 million people by the end of January, according to a statistical forecast released this week by the U.S. Centers for Disease Control and Prevention. 

The Ebola virus, shown in this scan from the Centers for Disease Control and Prevention,  could affect more than a million people in West Africa if left unchecked  [CREDIT:CDC/Virginia Tech] 

The CDC forecast supports the drastically higher projections released earlier by a group of scientists, including epidemiologists with the Virginia Bioinformatics Institute, who modeled the Ebola spread as part of a National Institutes of Health-sponsored project called Midas, short for Models of Infectious Disease Agent Study. 

The effort is also supported by the federal Defense Threat Reduction Agency. 
Before the scientists released results, the outbreak in West Africa was expected to be under control in nine months with only about 20,000 total cases.

But modeling showed 20,000 people could be infected in just a single month. 
The predictions could change dramatically if public health efforts become effective, but based on the virus's current uncontrolled spread, numbers of people infected could skyrocket. 
"If the disease keeps spreading as it has been we estimate there could be hundreds of thousands of cases by the end of the year in Liberia alone," said Bryan Lewis, a computational epidemiologist with the Network Dynamics and Simulation Science Laboratory at the Virginia Bioinformatics Institute. 
Lewis and his fellow researchers use a combination of models to predict outcomes of the epidemic. 

The Network Dynamics and Simulation Science Laboratory at the Virginia Bioinformatics  Institute modeled the rate of infections and how interventions would affect the rate  [CREDIT:CDC/Virginia Tech] 

The agent-based models are adaptive, evolving as more information is fed into them to provide an accurate forecast. 
Pharmaceutical intervention, which is still on the horizon, is proving less effective in the models than supportive care and personal protection equipment for health care workers.

 "The work with Ebola is not an isolated event," said Christopher Barrett, the executive director of the institute. "This research is part of a decades-long effort largely funded by the Defense Threat Reduction Agency to build a global synthetic population that will allow us to ask questions about our world and ourselves that we have never been able to ask before, and to use those answers to prevent or quickly intervene during a crisis." 

Barrett and other institute leaders updated U.S. Sen. Tim Kaine and Virginia Tech President Timothy Sands about the Network Dynamics and Simulation Science Lab's role in analyzing the Ebola outbreak at the Virginia Tech Research Center in Arlington on Tuesday morning. 
That afternoon in Blacksburg they briefed staff members from U.S. Sen. Mark Warner's office. A university-level Research Institute of Virginia Tech, the Virginia Bioinformatics Institute was established in 2000 with an emphasis on informatics of complex interacting systems scaling the microbiome to the entire globe. It helps solve challenges posed to human health, security, and sustainability. Headquartered at the Blacksburg campus, the institute occupies 154,600 square feet in research facilities, including state-of-the-art core laboratory and high-performance computing facilities, as well as research offices in the Virginia Tech Research Center in Arlington, Virginia. 


Source: Virginia Tech [September 26, 2014]

Read more at: http://archaeologynewsnetwork.blogspot.it/2014/09/computational-model-suggests-ebola.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)#.VCgF4Sh7DfU
Follow us: @ArchaeoNewsNet on Twitter | groups/thearchaeologynewsnetwork/ on Facebook

Non è il Pianeta delle scimmie.

Great apes face extinction: conservationist Jane Goodall


   The world's great apes face extinction within decades, renowned chimpanzee expert Jane Goodall warned Tuesday in a call to arms to ensure man's closest relatives are not wiped out. 

A chimpanzee at the zoo in Abidjan, Ivory Coast, 2014  [Credit: AFP/Sia Kambou]

 "If we don't take action the great apes will disappear, because of both habitat destruction as well as trafficking," Goodall told AFP in an interview in Nairobi. 
In the past half century, chimpanzee numbers have slumped from two million to just 300,000, spread over 21 countries, said Goodall, a British scientist who spent more than 
five decades studying chimpanzees in Tanzania's Gombe National Park.

 "If we don't change something, they certainly will disappear, or be left in tiny pockets where they will struggle from in-breeding," said 80-year-old Goodall, the first scientist to observe that apes as well as humans use tools. 

Experts predict that at the current rate, human development will have impacted 90 percent of the apes' habitat in Africa and 99 percent in Asia by 2030, according to a UN-backed report last month. 
Infrastructure development and extraction of natural resources -- including timber, minerals, oil and gas -- have devastated the prime habitat of apes and pushed chimpanzees, gorillas, bonobos, orangutans and gibbons closer to extinction. 

'We're schizophrenic' For Goodall, the destruction is part of mankind's wider attack on nature. "If we don't do anything to protect the environment, which we've already partially destroyed, I wouldn't want to be a child being born in 50 years time," Goodall added. "We're schizophrenic: we've got this amazing intelligence, but we seem to have lost the power of working in harmony with nature." 

British primatologist and anthropologist Jane Goodall gestures as she gives a talk on  her new book "Seeds of Hope" in Nairobi, Kenya in July 2014  

[Credit: AFP/Tony Karumba] 

As well as a tragic loss, Goodall said the death of man's closet relatives would act as a stark warning sign of climate change and global warming. "If we lose them (apes), it is probably because we have also lost the forests, and that would have a totally devastating impact on climate change," she said. 
"Climate change is so evident everywhere. There are leaders who say they don't believe in climate change, but I can't believe they really believe that, maybe they are just stupid." All species of apes are listed as endangered by the International Union for the Conservation of Nature (IUCN), some critically so. 
'Your life makes a difference' 
"People are losing the connection to the natural world," said Goodall. "You'd think that the most intellectual creature on the planet would know better than to destroy its only home, but we are destroying the planet very, very quickly." 

A Bornean orangutan (Pongo pygmaeus) in a close-up portrait in the rainforest  of Borneo.Orang Utans are critically endangered, mostly because their  habitat has decreased rapidly due to logging 

[Credit: Getty] 

But Goodall, who has set up volunteer conservation groups across the continent, urges people not to despair but to take action. "Climate change threatens every little part of the planet, and we can't stop that, but if we get together we can help to slow the effects," she said. 
Goodall recounted how in war-ravaged eastern Democratic Republic of Congo, children inspired by her conservation group negotiated with a local militia force, persuading the intially puzzled commander to give them access to replant trees on a hillside. 
"Within 30 minutes, all four soldiers with them had laid aside their guns and were helping the children to plant the trees," she said. "It is symbolic of what can happen if we can work together." 

"My last message to everybody, really, is to understand that your life matters, your life makes a difference," she said. "So many people give up and they feel hopeless.. and so do nothing. But if you take action locally, you can do something." 

Source: AFP [July 29, 2014]

Read more at: http://archaeologynewsnetwork.blogspot.it/2014/07/great-apes-face-extinction.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)#.U9kRYih7DfW
Follow us: @ArchaeoNewsNet on Twitter | groups/thearchaeologynewsnetwork/ on Facebook

Le 5 Minacce più gravi alla Specie Umana.

The five biggest threats to human existence 


  In the daily hubbub of current “crises” facing humanity, we forget about the many generations we hope are yet to come. Not those who will live 200 years from now, but 1,000 or 10,000 years from now. I use the word “hope” because we face risks, called existential risks, that threaten to wipe out humanity. These risks are not just for big disasters, but for the disasters that could end history.

Other ways humanity could end are more subtle  [Credit: United States Department of Energy, CC BY] 

Not everyone has ignored the long future though. 
Mystics like Nostradamus have regularly tried to calculate the end of the world. HG Wells tried to develop a science of forecasting and famously depicted the far future of humanity in his book "The Time Machine"!. 
Other writers built other long-term futures to warn, amuse or speculate. But had these pioneers or futurologists not thought about humanity’s future, it would not have changed the outcome. There wasn’t much that human beings in their place could have done to save us from an existential crisis or even cause one. We are in a more privileged position today. Human activity has been steadily shaping the future of our planet. And even though we are far from controlling natural disasters, we are developing technologies that may help mitigate, or at least, deal with them. 

Future imperfect

 Yet, these risks remain understudied. There is a sense of powerlessness and fatalism about them. People have been talking apocalypses for millennia, but few have tried to prevent them. Humans are also bad at doing anything about problems that have not occurred yet (partially because of the availability heuristic – the tendency to overestimate the probability of events we know examples of, and underestimate events we cannot readily recall). If humanity becomes extinct, at the very least the loss is equivalent to the loss of all living individuals and the frustration of their goals. But the loss would probably be far greater than that. Human extinction means the loss of meaning generated by past generations, the lives of all future generations (and there could be an astronomical number of future lives) and all the value they might have been able to create. If consciousness or intelligence are lost, it might mean that value itself becomes absent from the universe. This is a huge moral reason to work hard to prevent existential threats from becoming reality. And we must not fail even once in this pursuit. With that in mind, I have selected what I consider the five biggest threats to humanity’s existence. But there are caveats that must be kept in mind, for this list is not final. Over the past century we have discovered or created new existential risks – supervolcanoes were discovered in the early 1970s, and before the Manhattan project nuclear war was impossible – so we should expect others to appear. Also, some risks that look serious today might disappear as we learn more. The probabilities also change over time – sometimes because we are concerned about the risks and fix them. Finally, just because something is possible and potentially hazardous, doesn’t mean it is worth worrying about. There are some risks we cannot do anything at all about, such as gamma ray bursts that result from the explosions of galaxies. But if we learn we can do something, the priorities change. For instance, with sanitation, vaccines and antibiotics, pestilence went from an act of God to bad public health. 

1. Nuclear war. 

While only two nuclear weapons have been used in war so far – at Hiroshima and Nagasaki in World War II – and nuclear stockpiles are down from their the peak they reached in the Cold War, it is a mistake to think that nuclear war is impossible. In fact, it might not be improbable. The Cuban Missile crisis was very close to turning nuclear. If we assume one such event every 69 years and a one in three chance that it might go all the way to being nuclear war, the chance of such a catastrophe increases to about one in 200 per year. Worse still, the Cuban Missile crisis was only the most well-known case. The history of Soviet-US nuclear deterrence is full of close calls and dangerous mistakes. The actual probability has changed depending on international tensions, but it seems implausible that the chances would be much lower than one in 1000 per year. A full-scale nuclear war between major powers would kill hundreds of millions of people directly or through the near aftermath – an unimaginable disaster. But that is not enough to make it an existential risk. Similarly the hazards of fallout are often exaggerated – potentially deadly locally, but globally a relatively limited problem. Cobalt bombs were proposed as a hypothetical doomsday weapon that would kill everybody with fallout, but are in practice hard and expensive to build. And they are physically just barely possible. The real threat is nuclear winter – that is, soot lofted into the stratosphere causing a multi-year cooling and drying of the world. Modern climate simulations show that it could preclude agriculture across much of the world for years. If this scenario occurs billions would starve, leaving only scattered survivors that might be picked off by other threats such as disease. The main uncertainty is how the soot would behave: depending on the kind of soot the outcomes may be very different, and we currently have no good ways of estimating this. 

2. Bioengineered pandemic. 

Natural pandemics have killed more people than wars. However, natural pandemics are unlikely to be existential threats: there are usually some people resistant to the pathogen, and the offspring of survivors would be more resistant. Evolution also does not favor parasites that wipe out their hosts, which is why syphilis went from a virulent killer to a chronic disease as it spread in Europe. Unfortunately we can now make diseases nastier. One of the more famous examples is how the introduction of an extra gene in mousepox – the mouse version of smallpox – made it far more lethal and able to infect vaccinated individuals. Recent work on bird flu has demonstrated that the contagiousness of a disease can be deliberately boosted. Right now the risk of somebody deliberately releasing something devastating is low. But as biotechnology gets better and cheaper, more groups will be able to make diseases worse. Most work on bioweapons have been done by governments looking for something controllable, because wiping out humanity is not militarily useful. But there are always some people who might want to do things because they can. Others have higher purposes. For instance, the Aum Shinrikyo cult tried to hasten the apocalypse using bioweapons beside their more successful nerve gas attack. Some people think the Earth would be better off without humans, and so on. The number of fatalities from bioweapon and epidemic outbreaks attacks looks like it has a power-law distribution – most attacks have few victims, but a few kill many. Given current numbers the risk of a global pandemic from bioterrorism seems very small. But this is just bioterrorism: governments have killed far more people than terrorists with bioweapons (up to 400,000 may have died from the WWII Japanese biowar program). And as technology gets more powerful in the future nastier pathogens become easier to design. 

3. Superintelligence. 

Intelligence is very powerful. A tiny increment in problem-solving ability and group coordination is why we left the other apes in the dust. Now their continued existence depends on human decisions, not what they do. Being smart is a real advantage for people and organisations, so there is much effort in figuring out ways of improving our individual and collective intelligence: from cognition-enhancing drugs to artificial-intelligence software. The problem is that intelligent entities are good at achieving their goals, but if the goals are badly set they can use their power to cleverly achieve disastrous ends. There is no reason to think that intelligence itself will make something behave nice and morally. In fact, it is possible to prove that certain types of superintelligent systems would not obey moral rules even if they were true. Even more worrying is that in trying to explain things to an artificial intelligence we run into profound practical and philosophical problems. Human values are diffuse, complex things that we are not good at expressing, and even if we could do that we might not understand all the implications of what we wish for. Software-based intelligence may very quickly go from below human to frighteningly powerful. The reason is that it may scale in different ways from biological intelligence: it can run faster on faster computers, parts can be distributed on more computers, different versions tested and updated on the fly, new algorithms incorporated that give a jump in performance. It has been proposed that an “intelligence explosion” is possible when software becomes good enough at making better software. Should such a jump occur there would be a large difference in potential power between the smart system (or the people telling it what to do) and the rest of the world. This has clear potential for disaster if the goals are badly set. The unusual thing about superintelligence is that we do not know if rapid and powerful intelligence explosions are possible: maybe our current civilisation as a whole is improving itself at the fastest possible rate. But there are good reasons to think that some technologies may speed things up far faster than current societies can handle. Similarly we do not have a good grip on just how dangerous different forms of superintelligence would be, or what mitigation strategies would actually work. It is very hard to reason about future technology we do not yet have, or intelligences greater than ourselves. Of the risks on this list, this is the one most likely to either be massive or just a mirage. This is a surprisingly under-researched area. Even in the 50s and 60s when people were extremely confident that superintelligence could be achieved “within a generation”, they did not look much into safety issues. Maybe they did not take their predictions seriously, but more likely is that they just saw it as a remote future problem.

 4. Nanotechnology. 

Nanotechnology is the control over matter with atomic or molecular precision. That is in itself not dangerous – instead, it would be very good news for most applications. The problem is that, like biotechnology, increasing power also increases the potential for abuses that are hard to defend against. The big problem is not the infamous “grey goo” of self-replicating nanomachines eating everything. That would require clever design for this very purpose. It is tough to make a machine replicate: biology is much better at it, by default. Maybe some maniac would eventually succeed, but there are plenty of more low-hanging fruits on the destructive technology tree. The most obvious risk is that atomically precise manufacturing looks ideal for rapid, cheap manufacturing of things like weapons. In a world where any government could “print” large amounts of autonomous or semi-autonomous weapons (including facilities to make even more) arms races could become very fast – and hence unstable, since doing a first strike before the enemy gets a too large advantage might be tempting. Weapons can also be small, precision things: a “smart poison” that acts like a nerve gas but seeks out victims, or ubiquitous “gnatbot” surveillance systems for keeping populations obedient seems entirely possible. Also, there might be ways of getting nuclear proliferation and climate engineering into the hands of anybody who wants it. We cannot judge the likelihood of existential risk from future nanotechnology, but it looks like it could be potentially disruptive just because it can give us whatever we wish for. 

5. Unknown unknowns. 

The most unsettling possibility is that there is something out there that is very deadly, and we have no clue about it. The silence in the sky might be evidence for this. Is the absence of aliens due to that life or intelligence is extremely rare, or that intelligent life tends to get wiped out? If there is a future Great Filter, it must have been noticed by other civilisations too, and even that didn’t help. Whatever the threat is, it would have to be something that is nearly unavoidable even when you know it is there, no matter who and what you are. We do not know about any such threats (none of the others on this list work like this), but they might exist. Note that just because something is unknown it doesn’t mean we cannot reason about it. In a remarkable paper Max Tegmark and Nick Bostrom show that a certain set of risks must be less than one chance in a billion per year, based on the relative age of Earth. You might wonder why climate change or meteor impacts have been left off this list. Climate change, no matter how scary, is unlikely to make the entire planet uninhabitable (but it could compound other threats if our defences to it break down). Meteors could certainly wipe us out, but we would have to be very unlucky. The average mammalian species survives for about a million years. Hence, the background natural extinction rate is roughly one in a million per year. This is much lower than the nuclear-war risk, which after 70 years is still the biggest threat to our continued existence. The availability heuristic makes us overestimate risks that are often in the media, and discount unprecedented risks. If we want to be around in a million years we need to correct that. 

Author: Anders Sandberg  

Source: The Conversation [May 29, 2014]

Read more at: http://archaeologynewsnetwork.blogspot.it/2014/05/the-five-biggest-threats-to-human.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)#.U43Y7XJ_uSo
Follow us: @ArchaeoNewsNet on Twitter | groups/thearchaeologynewsnetwork/ on Facebook

La VI estinzione di massa: 2250, causata dall'Uomo.

C'è forse un po' di allarmismo. 

Ma sostanzialmente è vero che l'Uomo si sta comportando con la Terra come un agente infettivo troppo avido nei confronti del proprio ospite...

Un agente patogeno non troppo aggressivo (si pensi all'influenza) riesce infatti a vivere bene a spese della propria vittima, rispettandone le necessità di riproduzione e di sopravvivenza, in modo che ambedue possano coesistere a lungo nell'ambiente.

Un agente troppo aggressivo, invece, distrugge troppo efficacemente l'ospite e si estingue presto anch'egli (basta pensare ad Ebola). 

Humans will have

wiped out 75%

of species by 2250 

Humans will wipe out 75% of the species on Earth in around 240 years, a scientist has said. Mike Coffin, a marine geophysicist from the University of Tasmania, has said mankind will cause a mass extinction event between 240 and 500 years from now, which will see most species on the planet going extinct. 


According to Australia Broadcasting Corporation (ABC News), Coffin told a conference in Hobart that humans will cause the sixth mass extinction event to face the planet. The last five mass extinctions, which have taken place over the last 550 million years, were caused by asteroids hitting Earth, climate fluctuations and volcanic eruptions. The most devastating event took place around 250 million years ago. In the Permian event, 96% of species were lost following the combination of a massive volcanic eruption in Siberia, global warming and deep sea anoxic waters. If 75% of Earth's species were wiped out, as Coffin predicts, the loss would be similar to the best known extinction event – the Cretaceous–Paleogene extinction event – when a massive asteroid wiped out about three quarters of all plant and animal life on Earth, including all the dinosaurs. "We're on a trajectory to reach the 75% level sometime between 240 and 2,000 years from now," he told ABC. "Based on all threatened species as defined by the International Union for the Conservation of Nature ... assuming all of those threatened species become extinct then we would reach mass extinction somewhere between 240 and 540 years from now." He estimates that there are around 8.7 million species on Earth today, excluding the creatures and plants yet to be discovered. "We've only [discovered] about 15 per cent. So there is still 85 per cent that are yet to be discovered and or described." 

Discussing mankind's role in future mass extinction, he said "Homo sapiens have been around for 200,000 years - that's the length of our reign. The dinosaurs were around for 165 million years, so we're just a little blip on the geological time-scale. We haven't been around very long but we seem to be very good at driving a mass extinction ourselves." Animals that might survive the event include smaller ones that can breed quickly, such as cockroaches. "Species like us that don't reproduce until we're in our teens at earliest, with long gestation periods and that take a long time to evolve or adapt - big mammals - we're most vulnerable." However, Coffin also said he does not think mankind will kill all life on Earth: "Prior to the explosion of multi-cellular life 540 million years ago there were at least two episodes where the total surface of the Earth froze over - we call that a Snowball Earth. "There was single cell life back then, and even though the entire planet froze over some of that life survived. That's why we are here today." 

Author:  Hannah Osborne } Source: International Business Times [January 14, 2014]

Read more at: http://archaeologynewsnetwork.blogspot.it/2014/01/humans-will-have-wiped-out-75-of.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)
Follow us: @ArchaeoNewsNet on Twitter | groups/thearchaeologynewsnetwork/ on Facebook

Pro e contro del resuscitare animali estinti

The pros and cons of resurrecting

extinct animals


 Scientists from across the world have “scanned the horizon” in order to identify potentially significant medium and long-term threats to conservation efforts. Thylacine, or Tasmanian tiger Credit: E.J. Keller Baker/WikiCommons] Resurrection of several extinct species, the increasingly accelerated loss of wild rhinoceroses and a disastrous financial response to unburnable carbon are just some future global conservation issues flagged up in this year’s Horizon Scan, recently published in Trends in Ecology and Evolution. Professor William Sutherland and Dr Mark Spalding are amongst the 18 scientists who took part in this year’s Horizon Scan, seeking to identify potential future conservation issues in order to reduce the “probability of sudden confrontation with major social or environmental changes”. One such plausible issue is the resurrection or re-construction of extinct species, such as the woolly mammoth, passenger pigeon or the thylacine (a carnivorous marsupial). However, though there may be many benefits to the restoration of these animals, such a high-profile project could lead to attention and resources being diverted from attempts to thwart current threats to non-extinct species’ survival. Professor Sutherland said ‘There has been discussion of this idea for some time but it is now looking more practical and the idea is being taken seriously. A key issues is whether this is really a conservation priority’. Though the last woolly mammoth died around 4000 years ago, methods such as back-breeding, cloning and genetic engineering may lead to their resurrection. Not only could these extinct animals, and others such as the thylacine and the passenger pigeon, be re-constructed and returned to their native environments, they could potentially be used to “provide tools for outreach and education”. However, though this would be a conservational triumph, it could also hamper efforts to protect animals that are currently facing extinction, as both attention and resources would be diverted from preserving existing species and their habitats. Furthermore, there has not been any investigation into the “viability, ethics and safety of releasing resurrected species”, nor the effect their presence may have on indigenous flora and fauna. Another potential conservational issue identified by the Horizon Scan further highlights the problems facing species today. The loss of wild rhinoceroses and elephants is set to reaccelerate within the next few years, partially stimulated by a growing desire for ivory and horn. In 2013, it is estimated that over 600 rhinoceroses were poached for their horn in South Africa alone, out of a total global population of less than 26,000. Though an increased human population and proximity to growing infrastructure is partially responsible, organised crime syndicates and intensive hunting carry the weight of the blame. In the Asian countries that use it, rhinoceros horn is more expensive than gold. Demand for the precious horn is ever increasing, resulting in elevated levels of poaching. If attention and resources are diverted from the protection of these majestic animals, we may have yet more candidates for resurrection in the future. Altogether, this group of scientists identified the top 15 potential conservation issues (out of an initial group of 81 issues). In addition to the above topics, extensive land loss in southeast Asia from subsidence of peatlands, carbon solar cells as an alternative source of renewable energy, and an emerging fungal disease amongst snakes, have also been voted as plausible threats that need to be stopped before they can be realised. 

Source: University of Cambridge [December 24, 2013]
Read more at: http://archaeologynewsnetwork.blogspot.it/2013/12/the-pros-and-cons-of-resurrecting.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed:+TheArchaeologyNewsNetwork+(The+Archaeology+News+Network)
Read more at: http://archaeologynewsnetwork.blogspot.com/

OLTRE I LIMITI DELL'ETICA

Fresh effort to clone extinct animal

Scientists in Spain have received funding to test whether an extinct mountain goat can be cloned from preserved cells. The bucardo became extinct in 2000, but cells from the last animal were frozen in liquid nitrogen.

A Spanish mountain goat, the Pyrenean Ibex, was formally confirmed as extinct in 2000
when the last one of its kind was discovered dead [Credit: Gobierno de Aragon]

In 2003, a cloned calf was brought to term but died a few minutes after birth. Now, the scientists will test the viability of the female bucardo's 14-year-old preserved cells.

The bucardo, or Pyrenean ibex, calf born through cloning was an historic event: the first "de-extinction", in which a lost species or sub-species was resurrected.

The Aragon Hunting Federation signed an agreement with the Centre for Research and Food Technology of Aragon (CITA) in Zaragoza to begin preliminary work on the cells from the last animal, named Celia.

One of the scientists behind the cloning effort, Dr Alberto Fernandez-Arias, told BBC News: "At this moment, we are not initiating a 'bucardo recovery plan', we only want to know if Celia's cells are still alive after having been maintained frozen during 14 years in liquid nitrogen."

In addition to this in vitro work, they will also attempt to clone embryos and implant them in female goats.

"In this process, one or more live female bucardo clones could be obtained. If that is the case, the feasibility of a bucardo recovery plan will be discussed," Dr Fernandez-Arias, who is head of the Aragon Hunting, Fishing and Wetlands Service, explained.

The bucardo (Capra pyrenaica pyrenaica) was a sub-species of ibex, with distinct physical and genetic characteristics to other mountain goats inhabiting the Iberian Peninsula. It was perfectly adapted to life in its mountain habitat, and to survive the extreme cold and snow of winter in the Pyrenees.

However, its population had been declining for years for several reasons, including hunting. In April 1999, researchers captured the last animal, a female named Celia. They obtained skin biopsies and froze the tissue in liquid nitrogen at a temperature of -196C (-321F).

The following year, Celia was killed by a falling tree in the National Park of Ordesa in north-east Spain. But a team including Dr Fernandez-Arias, Jose Folch and others were able to inject nuclei from Celia's preserved cells into goat eggs that had been emptied of their own DNA.

Then they implanted the eggs into surrogates - hybrids between Spanish ibex and domestic goats. Of 57 implantations, seven animals became pregnant and one was carried to term.

The baby bucardo was born in 2003 - the first successful "de-extinction". But the clone of Celia died a few minutes later due to a defect in one of its lungs. Earlier this year, Dr Fernandez-Arias related the story in a TEDx talk, as part of a meeting on de-extinction.

Even if the new effort succeeds in producing healthy clones, any future recovery plan for the bucardo would be fraught with difficulty - especially given the only frozen tissue is from a lone female.

One possible approach for bringing back the bucardo might be to cross a healthy female bucardo clone with a closely related sub-species - such as the Spanish ibex (Capra pyrenaica hispanica) or the Gredos ibex (Capra pyrenaica victoriae) - and then selectively breeding the offspring to enhance traits typical of the bucardo.

Several other possibilities could also be explored. For instance, researchers have been able to reverse the sex of female mouse embryos by introducing a key gene that makes them develop as males.
Other options

In addition, George Church, professor of genetics at Harvard University, explained that a technique known as Crispr opened up new opportunities in the field of endangered species conservation and de-extinction. The technique allows researchers to edit genomes with extraordinary precision.

Such "genome editing" techniques could be used to introduce genetic diversity in populations that are so closely related it poses a threat to their survival.

"In some cases, you have a hunch as to what diversity is needed. You might specifically want diversity in the major histocompatibility complex [a large gene family involved in immune responses]," Prof Church told BBC News.

"For example, part of the problem with the Tasmanian devil is that they are so closely related in terms of their immune system that they have problems rejecting the facial tumour cells that they spread by biting each other."

However, he said, such techniques might eventually offer a way to extensively edit the genome of an Asian elephant to make it more like a mammoth, using a genetic sequence from the extinct animals.

Commenting on plans for the bucardo cells, the Aragon Hunting Federation said it wanted to "develop initiatives in the field of ecology in order to defend the natural environment".

The sum provided to fund the research at CITA has not been disclosed.

Author: Paul Rincon | Source: BBC News Website [November 22, 2013]

PROBLEMI della CLONAZIONE

Scientists produce cloned embryos of 

extinct frog

The genome of an extinct Australian frog has been revived and reactivated by a team of scientists using sophisticated cloning technology to implant a "dead" cell nucleus into a fresh egg from another frog species.

This is a gastric-brooding frog, Rheobatrachus silus, giving oral birth in the lab of Mike Tyler of the University of Adelaide [Credit: Mike Tyler, University of Adelaide]

The bizarre gastric-brooding frog, Rheobatrachus silus -- which uniquely swallowed its eggs, brooded its young in its stomach and gave birth through its mouth -- became extinct in 1983.

But the Lazarus Project team has been able to recover cell nuclei from tissues collected in the 1970s and kept for 40 years in a conventional deep freezer. The "de-extinction" project aims to bring the frog back to life.

In repeated experiments over five years, the researchers used a laboratory technique known as somatic cell nuclear transfer. They took fresh donor eggs from the distantly related Great Barred Frog, Mixophyes fasciolatus, inactivated the egg nuclei and replaced them with dead nuclei from the extinct frog. Some of the eggs spontaneously began to divide and grow to early embryo stage -- a tiny ball of many living cells.

Although none of the embryos survived beyond a few days, genetic tests confirmed that the dividing cells contain the genetic material from the extinct frog.

The results are yet to be published.

"We are watching Lazarus arise from the dead, step by exciting step," says the leader of the Lazarus Project team, Professor Mike Archer, of the University of New South Wales, in Sydney. "We've reactivated dead cells into living ones and revived the extinct frog's genome in the process. Now we have fresh cryo-preserved cells of the extinct frog to use in future cloning experiments.

"We're increasingly confident that the hurdles ahead are technological and not biological and that we will succeed. Importantly, we've demonstrated already the great promise this technology has as a conservation tool when hundreds of the world's amphibian species are in catastrophic decline."

The technical work was led by Dr Andrew French and Dr Jitong Guo, formerly of Monash University, in a University of Newcastle laboratory led by frog expert, Professor Michael Mahony, along with Mr Simon Clulow and Dr John Clulow. The frozen specimens were preserved and provided by Professor Mike Tyler, of the University of Adelaide, who extensively studied both species of gastric-brooding frog -- R. silus and R. vitellinus -- before they vanished in the wild in 1979 and 1985 respectively.

UNSW's Professor Archer spoke publicly for the first time today about the Lazarus Project and also about his ongoing interest in cloning the extinct Australian thylacine, or Tasmanian tiger, at the TEDx DeExtinction event in Washington DC, hosted by Revive and Restore and the National Geographic Society.

Researchers from around the world are gathered there to discuss progress and plans to 'de-extinct' other extinct animals and plants. Possible candidate species include the woolly mammoth, dodo, Cuban red macaw and New Zealand's giant moa.

Source: University of New South Wales [March 15, 2013]

Vorrei spendere due parole soltanto su quest'articolo: la rana in questione - estinta in epoca recente - non 'partorisce' davvero per via gastrica. Ma è vero che l'adulto ingoia le uova che si schiudono nella sua via digerente e quindi sembra mettere alla luce i piccoli in quel modo. In realtà depone normalmente le uova prodotte more solito.

La clonazione - descritta come la disattivazione/sostituzione dei nuclei - è molto più facile in specie animali inferiori ed è già nota e possibile. In specie animali superiori e più prossime all'uomo essa presenta invece numerose ed insidiose difficoltà, che non sono ancora state superate. La stessa pecora Dolly fu abbattuta prima che le patologie mortali da cui era affetta la uccidessero.

La clonazione a cui si riferisce l'ultima parte dell'articolo, su specie del tutto estinte in epoca preistorica è quindi molto più difficile. Tanto più, in quanto - con ogni probabilità - non si dispone di cellule congelate. Anche nel caso in cui si disponga dell'intero filamento del DNA (come ad esempio nel caso delle specie citate e anche del Neanderthal), ci sarebbero problemi di ' impacchettamento' del DNA stesso all'interno di un nucleo cellulare.

S'immagini di stipare i propri vestiti in una valigia, ma anche che questi vestiti siano 'attivi' come è attivo il DNA. Si può per esempio immaginare che questa valigia sia trasparente: a seconda di come si impacchetteranno i vestiti, differenti saranno i colori visibili dei vestiti. Ora, l'attività del DNA cambia a seconda della sua disposizione nello spazio.La Natura lo sa disporre correttamente nel nucleo delle cellule, noi no...

A parte questi problemi tecnici, esistono quelli etici, anch'essi insormontabili.

Il fatto che io possieda una pistola e sappia usarla, non mi autorizza a sparare indiscriminatamente: anche quando la clonazione dell'individuo fosse possibile già ora, essa non sarebbe eticamente approvabile.

 - Il movimento subdolamente  in atto da tempo è quello di sdoganare per gradi la clonazione d'interi individui (processo eticamente considerato non  corretto e niente affatto utile dal punto di vista medico sanitario), contro la clonazione di parti d'individuo (ad esempio d'organi, o di cellule di organi endocrini specializzati, a mezzo la scaffold bio-engeneering: cioé la costruzione di organi biologici con struttura di supporto artificiale), che è un processo eticamente visto con favore (ridurrebbe la necessità dei trapianti d'organo da vivente o da cadavere e ridurrebbe enormemente le difficoltà strutturali ed i costi dell'Eurotransplant in Europa, ad esempio).

Non sarebbe più necessario tenere conto - in diretta e su tutto il terrritoiro - della presenza di donatori con lo stesso assetto antigenico del ricevente: si confezionerebbe direttamente l'organo in modo sartoriale, per così dire, localmente.

In passato, si ipotizzò di creare un ibrido tra Uomo e Scimpanzé (che sono geneticamente molto simili e potrebbero dare - per inseminazione artificiale - un ibrido [fu detto 'scimpanzuomo'] come il mulo lo è per cavallo ed asino) per potere avere un 'parco' sempre disponibile di donatori d'organo. L'ibrido sarebbe per metà 'animale' (e quindi insensibile e sacrificabile?), ma sarebbe anche per metà veramente uomo. Naturalmente, l'ipotesi fu bocciata perché eticamente raccapricciante.

Quello cui si tende oggi, da parte di alcuni (passando per il Mammuth, che appartiene agli 'animali') è la realizzazione - per clonazione - di un Neanderthal, che viene considerato da alcuni, 'poco umano' o 'meno che umano', per poi passare all'homo sapiens sapiens. Lo scopo è riconoscibilissimo: non si trova nella scienza o nella medicina, bensì nei soldi e nella fama che tale acquisizione permetterebbe, dato l'impatto enorme sulla fantasia popolare...

Come si vede bene, le 'Armate Brancaleone'  composte di cialtroni chiassosi e ciarlatani iperattivi sono presenti in tutti i campi: e ovunque , se non fermati, potrebbero compiere danni anche gravissimi, contro la Scienza, la Cultura, l'Etica e - soprattutto - l'Uomo e la sua dignità.