Studiul demonstreaza ca o specie de ciori din Asia de sud-est este capabila sa recunoasca simboluri care semnifica diverse cantitati si unitati de masura.
Noul studiu, coordonat si efectuat de o echipa de ornitologi si etologi niponi condusa de profesorul Shoei Sugita din cadrul Universitatii Utsunomiya, s-a concentrat pe observarea detaliata a unui grup de 8 ciori cu cioc mare (Corvus macrorhynchos), din districtul Kullu Manali, statul Himachal Pradesh, India.
În prima parte a experimentelor, cercetatorii au estimat capacitatea pasarilor de a descoperi care dintre recipientele prezentate contineau hrana, pe baza unui simbol diferit atasat fiecarui recipient. Ciorilor le-au fost prezentate câte doua recipiente, unul gol, celalalt plin. Cel plin avea cifra 5, cel gol-cifra 2. Când pasarilor le-au fost prezentate ambele tipuri de recipiente, acestea le-au identificat dupa cifre pe cele pline, într-o proportie de 70%.
În cadrul celorlalte experimente, cercetatorii au schimbat cifrele atasate intial, cu litere sau simboluri de forme si dimensiuni diferite. Rezultatul final a aratat ca inteligentele pasari au avut o rata a succesului identificarii de 70 pâna la 90%, în functie de individ. Per total, cercetatorii niponi au efectuat 20 de experimente diferite, în care ciorile au dat de fiecare data dovada de inteligenta peste asteptari.
Studiile confirma din nou faptul ca aceste corvide sunt capabile sa distinga si chiar sa diferentieze cantitati, simboluri, forme. Alte studii anterioare desfasurate la Universitatea Utsunomya, au demonstrat abilitatea ciorilor de a distinge fetele femeilor de cele ale barbatilor. Specia ciorilor cu cioc mare din Himalaya prezinta tendinta naturala de a alege cantitatile mai mari de hrana, iar deciziile ciorilor au fost influentate de rata numerica si magnitudinea stimulilor.
Researchers working out of the National Institute of Advanced Industrial Science and Technology (AIST) in Tsukuba, Japan have developed a means for printing thin film transistors using InkJet technology. The team describes the process in their paper published in Nature.
To get around the problem of self-crystallization, inherent in other InkJet/transistor making processes, which result in spreading effects that make it difficult to print uniformly, the team instead chose to use a two step process, whereby one type of ink is sprayed first onto a substrate and is then followed by another immediately afterwards, directly on top of the first; the two then mix, creating an environment whereby one single crisp and sharp crystal grows and adheres to the material it is printed on.
The first ink applied is a liquid (anhydrous dimethylformamide) that holds a semiconductor but is not soluble. The second is comprised of an organic semiconductor in a solvent. After the first is sprayed onto the substrate, followed by a shot of the second, the two then mix naturally, and then, from a single point in the mixture a tiny crystal begins to grow, and keeps on growing until the entire pool of ink is consumed, resulting in a thin film (30-200nm thick) of C8BTBT affixed to the substrate. After printing a complete pattern with their new process onto a substrate, other components were added to complete the transistor.
Researchers are looking at InkJet sprayed transistor technologies in the hope that it could lead to a whole host of products that are based on bendable substrates, such as flexible displays, solar cells, large sheets of sensors, or true ePaper, and because it would offer a lowered cost of production compared to traditional silicon based products.
The authors say their new method offers exceptionally uniform creation of the crystals, a development that could lead InkJet sprayed technology out of the lab and into real world products. The team next plans to look into whether their new technique could also be used to create metal wires which would allow for a transistor to be made entirely from InkJet spraying technology.
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.
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.
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.
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."
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.
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.
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.
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.
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