Sam Harris is an American author, and neuroscientist, as well as the co-founder and current CEO of Project Reason. He received a Bachelor of Arts in philosophy from Stanford University, before receiving a Ph.D. in neuroscience from UCLA (2009). He is a proponent of scientific skepticism and is the author of The End of Faith (2004), which won the 2005 PEN/Martha Albrand Award, Letter to a Christian Nation (2006), a rejoinder to criticism of his first book, The Moral Landscape (2010), and Lying (2011).
He is a well-known contemporary critic of religion and a member of the New Atheism movement. Harris calls for separation of church and state, civil rights for the non-religious as well as freedom to criticize religion. Harris has also written numerous articles in Huffington Post, Los Angeles Times, The Washington Post, The New York Times, Newsweek as well as in scientific journals such as Nature. He has written articles on Islam, Christianity, and religion in general.
In his 2010 book, The Moral Landscape, he posits that science can shed light on questions regarding moral values and facilitate human well-being. After the release of his books, he continued to give numerous talks at institutions such as University of Oxford, Harvard, Cambridge, Caltech, UCSD, Stanford University, Tufts University as well as TED, where he proposed an expansion of the scientific method and the possible implications of its contribution to human morality. Harris has also made an appearance in the 2005 film The God Who Wasn't There, as well as numerous television appearances for Bill Maher and Bill O'Reilly.
Although always interested in religion, Harris grew up in a secular home with parents who rarely discussed God. Harris was married in 2004. His wife, Annaka Harris, is Co-Founder of Project Reason and an editor of scientific, nonfiction books.
Harris attended Stanford University as an English major, but dropped out of school. Harris has admitted experimenting with the drug ecstasy as a student and the powerful insights he felt it gave him into spirituality and psychology. Harris found himself interested in spiritual and philosophical questions when he was at Stanford and the notion that he might be able to achieve spiritual insights without the help of drugs. After leaving Stanford, he traveled to Asia, where he studied meditation with Hindu and Buddhist teachers. Eleven years later, he returned to Stanford and completed a B.A. degree in philosophy. In 2009 he earned a Ph.D. degree in neuroscience at University of California, Los Angeles, using functional magnetic resonance imaging to conduct research into the neural basis of belief, disbelief, and uncertainty.
“We’ve discovered a way to change the three-dimensional structure of a well-established semiconductor material to enable new optical properties while maintaining its very attractive electrical properties,” said Paul Braun, a professor of materials science and engineering and of chemistry who led the research effort.
The team published its advance in the journal Nature Materials.
Photonic crystals are materials that can control or manipulate light in unexpected ways thanks to their unique physical structures. Photonic crystals can induce unusual phenomena and affect photon behavior in ways that traditional optical materials and devices can’t. They are popular materials of study for applications in lasers, solar energy, LEDs, metamaterials and more.
Using an epitaxial approach, researchers developed a 3-D photonic crystal LED, the first such optoelectronic device. | Graphic by Eric Nelson
However, previous attempts at making 3-D photonic crystals have resulted in devices that are only optically active – that is, they can direct light – but not electronically active, so they can’t turn electricity to light or vice versa.
To create a 3-D photonic crystal that is both electronically and optically active, the researchers started with a template of tiny spheres packed together. Then, they deposit gallium arsenide (GaAs), a widely used semiconductor, through the template, filling in the gaps between the spheres.
The GaAs grows as a single crystal from the bottom up, a process called epitaxy. Epitaxy is common in industry to create flat, two-dimensional films of single-crystal semiconductors, but Braun’s group developed a way to apply it to an intricate three-dimensional structure.
“The key discovery here was that we grew single-crystal semiconductor through this complex template,” said Braun, who also is affiliated with the Beckman Institute for Advanced Science and Technology and with the Frederick Seitz Materials Research Laboratory at Illinois. “Gallium arsenide wants to grow as a film on the substrate from the bottom up, but it runs into the template and goes around it. It’s almost as though the template is filling up with water. As long as you keep growing GaAs, it keeps filling the template from the bottom up until you reach the top surface.”
The Illinois team’s photonic crystal has both properties.
“With our approach to fabricating photonic crystals, there’s a lot of potential to optimize electronic and optical properties simultaneously,” said Erik Nelson, a former graduate student in Braun’s lab who now is a postdoctoral researcher at Harvard University. “It gives you the opportunity to control light in ways that are very unique –to control the way it’s emitted and absorbed or how it propagates.”
To create a 3-D photonic crystal that is both electronically and optically active, the researchers started with a template of tiny spheres packed together. Then, they deposit gallium arsenide (GaAs), a widely used semiconductor, through the template, filling in the gaps between the spheres.
The GaAs grows as a single crystal from the bottom up, a process called epitaxy. Epitaxy is common in industry to create flat, two-dimensional films of single-crystal semiconductors, but Braun’s group developed a way to apply it to an intricate three-dimensional structure.
“The key discovery here was that we grew single-crystal semiconductor through this complex template,” said Braun, who also is affiliated with the Beckman Institute for Advanced Science and Technology and with the Frederick Seitz Materials Research Laboratory at Illinois. “Gallium arsenide wants to grow as a film on the substrate from the bottom up, but it runs into the template and goes around it. It’s almost as though the template is filling up with water. As long as you keep growing GaAs, it keeps filling the template from the bottom up until you reach the top surface.”
The epitaxial approach eliminates many of the defects introduced by top-down fabrication methods, a popular pathway for creating 3-D photonic structures. Another advantage is the ease of creating layered heterostructures. For example, a quantum well layer could be introduced into the photonic crystal by partially filling the template with GaAs and then briefly switching the vapor stream to another material.
Once the template is full, the researchers remove the spheres, leaving a complex, porous 3-D structure of single-crystal semiconductor. Then they coat the entire structure with a very thin layer of a semiconductor with a wider bandgap to improve performance and prevent surface recombination.
To test their technique, the group built a 3-D photonic crystal LED – the first such working device.
Now, Braun’s group is working to optimize the structure for specific applications. The LED demonstrates that the concept produces functional devices, but by tweaking the structure or using other semiconductor materials, researchers can improve solar collection or target specific wavelengths for metamaterials applications or low-threshold lasers.
“From this point on, it’s a matter of changing the device geometry to achieve whatever properties you want,” Nelson said. “It really opens up a whole new area of research into extremely efficient or novel energy devices.”
The U.S. Department of Energy and the Army Research Office supported this work. Other Illinois faculty involved in the project are electrical and computer engineering professors James Coleman and Xiuling Li, and materials science and engineering professor John Rogers.
Virusul contine peste 1.000 de gene, genomul sau fiind cu 6,5% mai mare decât cel al Mimivirus, fostul detinator al recordului de "cel mai mare virus".
Megavirus este de 10-20 de ori mai mare decât un virus obisnuit si este chiar mai mare decât unele bacterii, a declarat profesorul Jean-Michel Claverie de la Universitatea Aix-Marseille din Frnata.
"Pentru a vedea acest virus nu este nevoie de un microscop electronic, fiind vizibil si cu un microscop optic obisnuit", a declarat profesorul. Particula masoara aproximativ 0,7 micrometri în diametru.
Cercetatorii cred ca virusul
infecteaza amibe, organisme unicelulare ce traiesc în apa unde a fost descoperit Megavirus.
Aceasta descoperire confirma faptul ca virusurile gigant sunt descendentii unor celule complexe ce au devenit cu timpul mai simple, afirma profesorul Claverie.
Si sono tenuti teneramente la mano per 1500 anni prima di essere "scoperti". Gli scheletri di due amanti sepolti tra il quinto e il sesto secolo dopo Cristo sono stati rinvenuti a Modena, negli scavi archeologici di Via Ciro Menotti, in un'area ai limiti dell'antica città romana di Mutina (Modena appunto).
Le ossa, di un uomo e di una donna, appartenevano probabilmente a una coppia non molto ricca, e sono circondate da altre tombe di cui sette vuote, scavate e mai utilizzate.
La coppia di scheletri è stata rinvenuta qualche mese fa dalla Soprintendenza per i Beni Archeologici dell'Emilia Romagna negli scavi archeologici di Via Ciro Menotti (Modena). La notizia della scoperta è stata diffusa solo a metà ottobre. Foto credit: Soprintendenza per i Beni Archeologici dell'Emilia-Romagna
Lo scheletro della donna è rivolto verso quello dell'uomo, e forse anche quest'ultimo era girato verso la sposa. Qualcosa, forse un'inondazione del terreno di sepoltura, avrebbe poi fatto spostare il capo dell'uomo dall'altro lato. Secondo gli esperti in antichità non era infrequente che una coppia morisse negli stessi giorni.
Talvolta a causa di un'epidemia, capitava che mentre i parenti cercavano di seppellire uno dei due sposi, morisse anche l'altro nel giro di poche ore.
Ricky Dene Gervais (born 25 June 1961) is an English comedian, actor, director, radio presenter, producer, musician, and writer.
Gervais achieved mainstream fame with his television series The Office and the subsequent series Extras, both of which he co-wrote and co-directed with friend and frequent collaborator Stephen Merchant. In addition to writing and directing the shows, Gervais also played the lead roles of David Brent in The Office and Andy Millman in Extras. Gervais has also starred in a number of Hollywood films, assuming leading roles in Ghost Town and The Invention of Lying. He has performed on four sell-out stand-up comedy tours, written the best-selling Flanimals book series and starred with Stephen Merchant and Karl Pilkington in the most downloaded podcast in the world as of March 2009, The Ricky Gervais Show.
He has won multiple awards and honours, including seven BAFTA Awards, five British Comedy Awards, two Emmy Awards, three Golden Globe Awards and the 2006 Rose d'Or, as well as a Screen Actors Guild Award nomination. In 2007 he was voted the 11th greatest stand-up comic on Channel 4's 100 Greatest Stand-Ups and again in the updated 2010 list as the 3rd greatest stand-up comic. In 2010 he was named on the TIME 100 list of the world's most influential people. In 2010, Gervais became the first British person to host the Golden Globe Awards in 14 years; he returned to host in 2011 and is signed on to host in 2012.
In this personal narrative of the evolution of his faith, Ricky Gervais describes how and why he became an atheist.
Passo dopo passo, in fila indiana. Di più non consente questo sentiero sgangherato che si affaccia sulla gola di El Chorro, in Andalusia (Spagna meridionale). Il Caminito del Rey (il "cammino del re", in onore del sovrano Alfonso XIII che vi camminò nel 1921), è un antico passaggio ricavato nei primi anni del '900 sulle ripide pareti di arenaria, a oltre 100 metri dal fiume sottostante. Originariamente costruito per collegare due impianti idroelettrici limitrofi e consentire ai lavoratori di trasportare materiale tra uno e l'altro, è ora pericolante in molte sue parti e interrotto in alcuni punti. Sgangherato e pericoloso è ora chiuso al pubblico. Ma questi scalatori, debitamente attrezzati e messi in sicurezza, hanno voluto percorrerlo prima che inizino i grandi lavori di ristrutturazione per sistemarlo.
Anche i sostenitori delle vacanze avventurose potrebbero vacillare di fronte all'insolita "piazzola" scelta per queste tende. Per i campeggiatori che vi alloggiano, invece, si tratta di ordinaria amministrazione: quello che vedete, infatti, è il bivacco di una cordata di scalatori esperti - e un po' spericolati - immortalati dal fotografo del National Geographic Gordon Wiltsie sulle pareti del Great Sail Peak, un muro di granito che svetta sull'isola di Baffin, in Canada. Queste arrampicate, ha spiegato Wiltsie, possono durare anche alcuni giorni ed è necessario organizzare alcuni momenti di riposo, anche se a 1200 metri, come in questo caso. E i rischi sono sempre dietro l'angolo. Durante la primavera artica, per esempio, lo scioglimento della neve può provocare il distacco di massi che rotolano pericolosamente a pochi centimetri dagli scalatori.
The discovery explains the mechanism of this memory -- a sort of biological switch -- and how it can also be inherited by offspring.
The work was led by Professor Martin Howard and Professor Caroline Dean at the John Innes Centre.
Professor Dean said: "There are quite a few examples that we now know of where the activity of genes can be affected in the long term by environmental factors. And in some cases the environment of an individual can actually affect the biology or physiology of their offspring but there is no change to the genome sequence."
For example, some studies have shown that in families where there was a severe food shortage in the grandparents' generation, the children and grandchildren have a greater risk of cardiovascular disease and diabetes, which could be explained by epigenetic memory. But until now there hasn't been a clear mechanism to explain how individuals could develop a "memory" of a variable factor, such as nutrition.
The team used the example of how plants "remember" the length of the cold winter period in order to exquisitely time flowering so that pollination, development, seed dispersal and germination can all happen at the appropriate time.
Professor Howard said: "We already knew quite a lot about the genes involved in flowering and it was clear that something goes on in winter that affects the timing of flowering, according to the length of the cold period."
Using a combination of mathematical modelling and experimental analysis the team has uncovered the system by which a key gene called FLC is either completely off or completely on in any one cell and also later in its progeny. They found that the longer the cold period, the higher the proportion of cells that have FLC stably flipped to the off position. This delays flowering and is down to a phenomenon known as epigenetic memory.
Epigenetic memory comes in various guises, but one important form involves histones -- the proteins around which DNA is wrapped. Particular chemical modifications can be attached to histones and these modifications can then affect the expression of nearby genes, turning them on or off. These modifications can be inherited by daughter cells, when the cells divide, and if they occur in the cells that form gametes (e.g. sperm in mammals or pollen in plants) then they can also pass on to offspring.
Together with Dr Andrew Angel (also at the John Innes Centre), Professor Howard produced a mathematical model of the FLC system. The model predicted that inside each individual cell, the FLC gene should be either completely activated or completely silenced, with the fraction of cells switching to the silenced state increasing with longer periods of cold.
To provide experimental evidence to back up the model, Dr Jie Song in Prof. Dean's group used a technique where any cell that had the FLC gene switched on, showed up blue under a microscope. From her observations, it was clear that cells were either completely switched or not switched at all, in agreement with the theory.
Dr Song also showed that the histone proteins near the FLC gene were modified during the cold period, in such a way that would account for the switching off of the gene.
Funding for the project came from BBSRC, the European Research Council, and The Royal Society.
Professor Douglas Kell, Chief Executive, BBSRC said: "This work not only gives us insight into a phenomenon that is crucial for future food security -- the timing of flowering according to climate variation -- but it uncovers an important mechanism that is at play right across biology. This is a great example of where the research that BBSRC funds can provide not only a focus on real life problems, but also a grounding in the fundamental tenets of biology that will underpin the future of the field. It also demonstrates the value of multidisciplinary working at the interface between biology, physics and mathematics."
O echipa de cercetatori de la Universitatea Stanford din California a descoperit ca modificarile a trei tipuri de proteine pot afecta longevitatea.
Studiind blocarea sau modificarea lor la o specie de nematode (viermi cilindrici) care au acelasi proteine ca si oamenii, s-a observat ca durata de viata a fost afectata atât la viermii în cauza, cât si la urmatoarele 3 generatii, înregistrându-se o crestere a sperantei de viata cu pâna la 30 de procente. Dupa a treia generatie, durata de viata are tendinta de a reveni la normal.
Este pentru prima data când oamenii de stiinta au descoperit ca un factor mostenit afecteaza durata de viata, fara a fi vorba de schimbari genetice. Genele nu au fost afectate, iar în timp ce longevitatea s-a transmis la generatiile urmatoare, nivelul celor trei proteine a ramas acelasi.
Acest fenomen poarta numele de schimbare epigenetica. Conceptul, în ansamblu, nu este nou si descrie procesul prin care corpul se adapteaza la factorii de mediu precum: dieta, lumina soarelui, nivelul poluarii. Nu se stiuse însa pâna acum ca asemenea adaptari ar putea fi mostenite în urmatoarele câteva generatii.
Corpul poseda, se pare, un fel de "amintiri" legate de stilului de viata al generatiilor anterioare, iar longevitatea ar putea fi mostenita, timp de câteva generatiii, si pe o cale non-genetica.
În cazul în care aceasta legatura se va descoperi si în cazul oamenilor, ea ar putea marca un progres major în genetica.
Aceste proteine modificate de catre oamenii de stiinta se gasesc în nucleul tuturor celulelor umane si ajuta la mentinerea moleculelor de ADN într-o forma compacta în interiorul lor.
Clinton Richard Dawkins, FRS, FRSL (born 26 March 1941), known as Richard Dawkins, is a British ethologist, evolutionary biologist and author. He is an emeritus fellow of New College, Oxford, and was the University of Oxford's Professor for Public Understanding of Science from 1995 until 2008.
While many in the scientific community are excited at the prospect of battling aging, Richard Dawkins considers the idea foolish and a little presumptuous asking, are we really prepared to be the last generation to reproduce?
Dawkins came to prominence with his 1976 book The Selfish Gene, which popularised the gene-centered view of evolution and introduced the term meme. In 1982 he introduced an influential concept into evolutionary biology, presented in his book The Extended Phenotype, that the phenotypic effects of a gene are not necessarily limited to an organism's body, but can stretch far into the environment, including the bodies of other organisms.
Dawkins is an atheist and humanist, a Vice President of the British Humanist Association and supporter of the Brights movement. He is well known for his criticism of creationism and intelligent design. In his 1986 book The Blind Watchmaker, he argued against the watchmaker analogy, an argument for the existence of a supernatural creator based upon the complexity of living organisms. Instead, he described evolutionary processes as analogous to a blind watchmaker. He has since written several popular science books, and makes regular television and radio appearances, predominantly discussing these topics. In his 2006 book The God Delusion, Dawkins contends that a supernatural creator almost certainly does not exist and that religious faith is a delusiona fixed false belief. As of January 2010 the English-language version has sold more than two million copies and had been translated into 31 languages.
Il volto dipinto di questa donna Tuareg non sarà certo passato inosservato durante l'ultima Cure Salee, la "cura del sale" o Festival dei Nomadi che si tiene ogni settembre nelle piscine saline nei pressi di Ingall, Niger settentrionale. Tuareg, Peul e Wodaabe, le popolazioni nomadi della regione, accorrono in questa zona per far rinfrescare il bestiame e festeggiare la fine della stagione delle piogge. Si pensa che il sale abbia effetti benefici sulla salute degli animali e dei pastori. Ma probabilmente a far bene all'umore sono i rapporti umani che dopo mesi di lavoro e solitudine, si riallacciano. È questa l'occasione per cercare marito, ballare, cantare e raccontare le ultime novità agli amici ritrovati. Per attirare l'attenzione, gli uomini si esibiscono in prove di forza e parate, e ciascuno sfoggia il tradizionale make-up.
Tagliare e sbucciare una zucca è già di per sé un'operazione tutt'altro che semplice. Immaginatevi quanta abilità servirebbe per ricavarne un faccione pensieroso come questo. Lo zuccone è opera di Ray Villafane, 42enne americano specializzato nella scultura del vegetale arancione. Altro che la classica zucca con ghigno malefico, in occasione di Halloween - che si festeggia proprio oggi - l'artista si è sbizzarrito con cucchiai e scalpelli dando vita a "volti" bitorzoluti ed espressioni da gargoil. Il trucco, ha spiegato Villafane, che è un ex insegnante di arte, è considerare la zucca alla stregua di un pezzo di argilla. Sceglierne una soda e ricca di polpa, meglio se un po' deforme: darà l'ispirazione per qualche buffa variazione sul tema.
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