Medicii de la Spitalul general Ben Taub din Houston, Texas, testeaza efectele ketaminei asupra oamenilor care sufera de o forma severa a depresiei. Ei spun ca aceasta substanta, care are capacitatea de a amorti simturile printr-o stare de anestezie disociativa, poate înlatura starile depresive.

Tratamentul actual care este utilizat în cazul depresiei îsi face efectul în câteva saptamâni, timp în care pacientii înregistreaza tendinte de suicid. Ketamina, în schimb, îsi face efectul imediat dupa administrare.

Pacientii tratati în studiu au declarat ca în primele 24 de ore de la administrarea ketaminei s-au calmat si relaxat. "Înainte, totul era în ceata. Dupa tratamentul cu ketamina am simtit ca pot începe o viata noua, sa merg acasa si sa îmi vad prietenii sau sa fac cumparaturi si sa gatesc pentru familia mea", a declarat pacienta Heather Merrill, mama a trei copii.

Daca rezultatele studiului vor fi validate, cercetatorii vor prelungi perioada de testare si vor încerca sa administreze trei doze de ketamina pe saptamâna, pentru a observa efectele pe termen lung. De asemenea, daca totul merge conform planului, ei spera sa creeze o pastila ca alternativa la tratamentul intravenos.

Ketamina poate cauza unele probleme la nivelul vezicii urinare, iar unele studii sugereaza ca ea ar putea crea probleme cardiace, putând chiar sa înrautateasca sanatatea mintala.

Sursa: Daily Mail - via Descopera.ro

Many physicists around the world are hard at work trying to figure out new and exciting ways to create ultra-cold objects, the reason being is that if a system could be created that operates at or at least very near absolute zero, superconductors could be devised that might help create quantum computers, which would of course run at speeds that would make the current generation look quaint. Plus, theory suggests new states of matter might be discovered.

Now, new work by a group of physicists from Harvard appears to be coming closer than ever. They’ve figured out a way to remove entropy from a specialized system leaving much colder atoms behind. In their paper, published in Nature, they discuss how they’ve come up with something called an orbital excitation blockade, a form of interaction blockade, to reach temperatures tens to hundreds of times colder than current methods.

The team did their research in a three step process. In the first they shot atoms that make up rubidium with a laser, forcing them to glow in a way that made them give off more energy then they absorbed, making them cooler of course. By doing so they also created a system whereby they were able to control the atoms due to the pressure created by the laser. Thus they could hold them still, move them around, or even cause them to run into each other.

Next, the team caused the atoms to grow even colder by allowing evaporative cooling to due its work.

After that, the real work began. Here the team used meshes of lasers, called optical lattices to remove entropy from the system. The already cooled atoms were made to knock into one another using lasers ala the method used to start the whole process; this time in the optical lattices. In so doing, the excited activity of atom one dampened the excited activity of the other, a process the team calls an orbital excitation blockade. The team then removed the excited atoms from the system, leaving the unexcited, cold atoms behind, in effect, removing entropy from the system.

In actual experiments done thus, far, the team has demonstrated an ability to actually remove heat from a system using their excitation blockade, but only to a certain point. They believe more research will allow them to reach temperatures tens or even hundreds of a billionth of a degree above absolute zero, which would take them into truly unknown territory.

More information: Orbital excitation blockade and algorithmic cooling in quantum gases, Nature, 480, 500–503 (22 December 2011) doi:10.1038/nature10668

Abstract

Interaction blockade occurs when strong interactions in a confined, few-body system prevent a particle from occupying an otherwise accessible quantum state. Blockade phenomena reveal the underlying granular nature of quantum systems and allow for the detection and manipulation of the constituent particles, be they electrons, spins, atoms or photons. Applications include single-electron transistors based on electronic Coulomb blockade7 and quantum logic gates in Rydberg atoms. Here we report a form of interaction blockade that occurs when transferring ultracold atoms between orbitals in an optical lattice. We call this orbital excitation blockade (OEB). In this system, atoms at the same lattice site undergo coherent collisions described by a contact interaction whose strength depends strongly on the orbital wavefunctions of the atoms. We induce coherent orbital excitations by modulating the lattice depth, and observe staircase-like excitation behaviour as we cross the interaction-split resonances by tuning the modulation frequency. As an application of OEB, we demonstrate algorithmic cooling of quantum gases: a sequence of reversible OEB-based quantum operations isolates the entropy in one part of the system and then an irreversible step removes the entropy from the gas. This technique may make it possible to cool quantum gases to have the ultralow entropies required for quantum simulation of strongly correlated electron systems. In addition, the close analogy between OEB and dipole blockade in Rydberg atoms provides a plan for the implementation of two-quantum-bit gates in a quantum computing architecture with natural scalability.

A Harvard University press release can be found below:

Physicists at Harvard University have realized a new way to cool synthetic materials by employing a quantum algorithm to remove excess energy. The research, published this week in the journal Nature, is the first application of such an "algorithmic cooling" technique to ultra-cold atomic gases, opening new possibilities from materials science to quantum computation.

"Ultracold atoms are the coldest objects in the known universe," explains senior author Markus Greiner, associate professor of Physics at Harvard. "Their temperature is only a billionth of a degree above absolute zero temperature, but we will need to make them even colder if we are to harness their unique properties to learn about quantum mechanics."

Greiner and his colleagues study quantum many-body physics, the exotic and complex behaviors that result when simple quantum particles interact. It is these behaviors which give rise to high-temperature superconductivity and quantum magnetism, and that many physicists hope to employ in quantum computers.

"We simulate real-world materials by building synthetic counterparts composed of ultra-cold atoms trapped in laser lattices," says co-author Waseem Bakr, a graduate student in physics at Harvard. "This approach enables us to image and manipulate the individual particles in a way that has not been possible in real materials."

The catch is that observing the quantum mechanical effects that Greiner, Bakr and colleagues seek requires extreme temperatures.

"One typically thinks of the quantum world as being small," says Bakr, " but the truth is that many bizarre features of quantum mechanics, like entanglement, are equally dependent upon extreme cold."

The hotter an object is, the more its constituent particles move around, obscuring the quantum world much as a shaken camera blurs a photograph.

The push to ever-lower temperatures is driven by techniques like "laser cooling" and "evaporative cooling," which are approaching their limits at nanoKelvin temperatures. In a proof-of-principle experiment, the Harvard team has demonstrated that they can actively remove the fluctuations which constitute temperature, rather than merely waiting for hot particles to leave as in evaporative cooling.

Akin to preparing precisely one egg per dimple in a carton, this "orbital excitation blockade" process removes excess atoms from a crystal until there is precisely one atom per site.

"The collective behaviors of atoms at these temperatures remain an important open question, and the breathtaking control we now exert over individual atoms will be a powerful tool for answering it," said Greiner. "We are glimpsing a mysterious and wonderful world that has never been seen in this way before."

Source: PhysOrg - via ZeitNews.org

Julian Assange, founder and Editor-in-Chief of WikiLeaks, has been under house arrest, without charge, for almost 500 days. Over the past two months, his temporary home in the English countryside has played host to a series of extraordinary conversations with some of the most interesting and controversial people alive in the world today. 

“The World Tomorrow” is a collection of twelve interviews featuring an eclectic range of guests, who are stamping their mark on the future: politicians, revolutionaries, intellectuals, artists and visionaries. The world's last five years have been marked by an unrelenting series of economic crises and political upheavals. But they have also given rise to the eruption of revolutionary ferment in the Middle East and to the emergence of new protest movements in the Euro-American world. In Julian's words, the aim of the show is “to capture and present some of this revolutionary spirit to a global audience. My own work with WikiLeaks hasn't exactly made my life easier”, says Assange, “but it has given us a platform to broadcast world-shifting ideas.” 

For Julian, part of the show's strength lies in its “frank and irreverent tone”. “My conviction is that power can only be transformed if it is taken seriously – but ordinary people must resist the temptation to defer to the powerful."

The original music for the show has been composed by British-Sri Lankan artist M.I.A. 

The first interview will be broadcast on RT on Tuesday 17 April, at 11:00 London time. Subsequent interviews, edited to last 26 minutes each, will be broadcast on a weekly basis. The interviews and transcripts will also be made available online. Arrangements are currently being made with other licensees to publish longer edits of the series. For more information on the show, please visit worldtomorrow.wikileaks.orghttp://worldtomorrow.wikileaks.org

FREQUENTLY ASKED QUESTIONS (FAQs) 

:: Who is producing “The World Tomorrow”? 

The show is being produced by Quick Roll Productions, a company established by Julian Assange. 
The main production partner is Dartmouth Films, a UK producer of independent films. Indispensable help and advice has been received from friends and supporters of WikiLeaks. If your network is interested in licensing the show, please visit the website of the distributor, Journeyman Pictures (http://www.journeyman.tv/63130/about-us/how-to-find-us.html). 

:: What has RT got to do with “The World Tomorrow”? 

RT is the first broadcast licensee of the show, but has not been involved in the production process. All editorial decisions have been made by Julian Assange. RT's rights encompass the first release of 26-minute edits of each episode in English, Spanish and Arabic.

:: Will the full material recorded during the interviews be made available? 

We are devoted to making available as much material as possible within the constraints of Julian's circumstances. Longer edits of the episodes will be released in due course, and transcripts of the interviews will be published on the show's independent website, worldtomorrow.wikileaks.org. (http://worldtomorrow.wikileaks.org./) 

:: Who is Julian Assange? 

Julian Assange is an Australian-born publisher, entrepreneur and internet activist. He is the Editor-in-Chief of WikiLeaks, which he founded in 2006. Since then, WikiLeaks has been responsible for releasing the biggest leaks in history, including the Afghan (http://wikileaks.org/afg/) and Iraq (http://wikileaks.org/irq/) War Logs, the Collateral Murder Video (http://collateralmurder.com/), Cablegate (http://wikileaks.org/cablegate.html) and the Global Intelligence File (http://wikileaks.org/the-gifiles.html)s. Julian and WikiLeaks have received a number of awards for journalism and campaigning, including: The Economist Award for Freedom of Expession (2008), the Amnesty International Media Award (2009), the Le Monde Person of the Year (2010), The Sydney Peace Foundation Gold Medal (2011), the Martha Gellhorn Prize for Journalism (2011) and the Walkley Award for Outstanding Contribution to Journalism (2011). He won the popular vote for TIME Person of the Year 2010. 

:: What is the current status of Julian Assange? 

As of Friday 13 April 2012, Julian has been under house arrest (http://justice4assange.com/), without charge, for 492 days. This follows on from his imprisonment in solitary confinement, also without charge, in December 2010. Julian is currently residing at a supporter's home in the English countryside, as dictated by his bail conditions. He is forced to wear an electronic manacle around his ankle at all times. Monitoring units are installed in the house and report to the British government via the security contractor, G4S (http://www.guardian.co.uk/uk/2011/mar/16/mubenga-g4s-face-charges-death). 

A closed United States Grand Jury investigation into Julian Assange has been active in the USA for 574 days. Julian is currently awaiting the result of his UK Supreme Court appeal against his extradition to Sweden (http://www.swedenversusassange.com/). Information leaked to WikiLeaks from the email accounts of US private intelligence agency Stratfor (the “shadow CIA (http://english.al-akhbar.com/content/stratfor-wanted-assange-out-any-means)”), show that the United States government issued a sealed indictment (http://wikileaks.org/Stratfor-Emails-US-Has-Issued.html) against Julian Assange as early as January 2011. 

More info: http://justice4assange.com/

:: What is the current status of WikiLeaks? 

Despite 495 days of unlawful financial blockade (http://www.wikileaks.org/Banking-Blockade.html) by a cartel made up of VISA, Mastercard, the Bank of America, Western Union and PayPal, and despite severe restrictions on the liberty of Julian Assange, WikiLeaks is continuing its operations as normal, to the best of its abilities. On Monday 27 February 2012, WikiLeaks began publishing the Global Intelligence Files (http://wikileaks.org/the-gifiles.html), over five million emails from Texas-based “global intelligence” firm Stratfor. WikiLeaks is conducting its activities in conjunction with over ninety media partners all over the globe. A number of formal actions against the banking blockade are active in Europe and South America. 

More info: http://wikileaks.org/Banking-Blockade

http://worldtomorrow.wikileaks.org/
http://justice4assange.com/
http://wikileaks.org
http://wikileaks.org/Banking-Blockade.html

Source: http://www.twitlonger.com/show/gunqv7

Con il Large Hadron Collider (Lhc) ci eravamo lasciati lo scorso dicembre: i tecnici del Cern di Ginevra avevano tra le mani una traccia da seguire per individuare la particella più ricercata al mondo, il bosone di Higgs (gli studi sono stati da poco sottoposti a varie riviste, tra cui Physics Letter B, da Atlas e Cms). Da anni gli scienziati cercano di provare l'esistenza di questa entità subatomica necessaria per avvalorare la teoria del Modello Standard sull'origine di tutta la materia che occupa l'universo. Ebbene, giusto in questi giorni Lhc torna in piena attività per raccogliere nuovi dati. Ma stavolta i fisici faranno toccare un nuovo record all'acceleratore, alimentandolo con 4 teraelettronvolt (TeV). E intanto gli scienziati il 15 febbraio alle ore 19:00 faranno una chiacchierata con gli internauti su Google+, in diretta dalle profondità di Ginevra. Per partecipare  basta avere un profilo sul social netwok e aggiungere +Cms Experiment alle proprie cerchie. Qui i dettagli.

Come spiega Wired.co.uk, l'energia di collisione utilizzata per il prossimo ciclo di esperimenti di Lhc è stata innalzata del 14% rispetto ai valori del 2011. Una scelta tecnica dettata dal fatto che a partire dal prossimo novembre l' acceleratore dovrà restare chiuso per 20 mesi in attesa di avviare ulteriori esperimenti nel 2015. A partire dalle prossime settimane, i fisici del Cern potranno così raccogliere preziosi dati utili ad approfondire la natura del bosone.

Infatti, l'immensa mole di risultati ottenuti dagli esperimenti del 2011 non ha ancora permesso agli scienziati di dare una risposta chiara all'interrogativo che li assilla da più di 50 anni: quale sia la massa del bosone di Higgs. Finora i fisici hanno utilizzato Lhc per far scontrare fasci di protoni a altissima velocità nella speranza di poter osservare anche solo per un istante una piccola traccia dell'esistenza della particella fondamentale.  

Dall'analisi dei dati raccolti lo scorso anno i ricercatori avevano individuato qualche segnale interessante intorno ai valori di riferimento di 125 gigaelettronvolt (GeV), ma si erano anche imbattuti in una nuova particella subatomica simile al bosone chiamata Chi_b(3P). Insomma, solo aumentando il numero di collisioni i fisici possono sperare di imbattersi per la prima volta in una traccia inconfutabile. Ecco perché, come suggerisce Scientific American, il Cern ha voluto premere sull'acceleratore Lhc per ottenere il 30% di dati in più. 

Fonte: Wired.it