10/31/09
Oomega-3 rasvhapete tervisemõju on erinev
Tara Kelly selgitab Time'is, et südame- ja ajusõbralikud oomega-3 rasvhapped ei ole kõik päris võrdsete tervisemõjudega, mis on põhjustanud diskussiooni selle üle, kas toiduainetes oomega-3 rasvhappeid kasutavad ja nende sisaldust reklaamivad kaupmehed peaksid ära näitama ka nende päritolu.Think of omega-3s as the oils that keep our brains and hearts from getting rusty. Hundreds of studies show that these essential fatty acids can help prevent cardiovascular disease and some scientists believe they are also beneficial for the brain and nervous system. But not all omega-3s are created equal. The ones with the biggest health benefits are found in fish like salmon and mackerel, which have the two long chain fatty acids docosahexaenoic (DHA) and eicosapentaenoic (EPA). Plant-derived omega-3s — the fatty acids found in flax seeds, olive oil and some leafy greens — don't contain these specific fatty acid chains. While they're also thought to be good for the heart, they don't have quite the same effect on the body as their fish-derived cousins.
10/30/09
Miks on inimesed erilised loomad
LiveScience toob välja 10 peamist eripära, mis inimese muust loomariigist esile kergitavad.Humans are unusual animals by any stretch of the imagination, ones that have changed the face of the world around us. What makes us so special when compared to the rest of the animal kingdom? Some things we take completely for granted might surprise you.
Kuidas kummitused tekivad?
Hazel Muir kirjutab New Scientistis katsetest mõista, kuidas tekitab inimaju illusioone kummitustest ning teooriast, mille kohaselt on üheks vaimunägemuste põhjustajaks ebaharilikud magnetväljad.It was in the 1970s that Michael Persinger, a neuroscientist from Laurentian University in Sudbury, Ontario, Canada, proposed that some hallucinations could be triggered by magnetic fields. It is well established that magnetic pulses of 1 or 2 teslas can stimulate neurons in the brain; it is sometimes used to treat depression. Persinger, however, was interested in much weaker fields, of about 1 to 10 microtesla, which can arise from electrical equipment such as a hairdryer, or simply exist in natural background fields.
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Doktor Susan Calvin äratatakse ellu
Alison Flood teatab Guardianis, et Mickey Zucker Reichert äratab taas raamatulehtedel ellu ulmegigandi Isaac Asimovi I, Robot jutusarjast tuntud doktor Susan Calvini.The first of three books, Robots and Chaos, will follow Calvin as she goes through a medical internship while coming to terms with what it means to be human in a near-future world populated by robots.
Kui tillukesed on väikesed asjad?
Stuart Fox tutvustab Popular Science'is Utah ülikooli uurijate loodud näitlikku õppevahendit, mis illustreerib selgelt ja kujundlikult, kui tillukesed on meie maailma kõige pisemad objektid.One of the most difficult aspects of science is conceptualizing some of the unbelievably large, (and unimaginably small) numbers that routinely pop up. The Universe is 5.5 x 10^23 miles across. A human hair is about 7 x 10^-4 inches across. Hard to imagine how things like cells, proteins and atoms all relate to one another. Now, at least for the very small things, the University of Utah has developed a fun little Flash graphic to make sense of all of it.
Playdar - uued tuuled netimuusikas
Jim Giles tutvustab New Scientistis suure potentsiaaliga veebimussiteenust Playdar, mis muudab internetis muusika otsimise, leidmise ja kuulamise senisest oluliselt lihtsamaks.You can think of Playdar as a language that lets music players like iTunes or any music website talk to music libraries such as Spotify. Players that "speak" Playdar can ask libraries for a track, and if the library has the right song, it starts streaming without the user having to think about where the music is stored.
NASA hakkab pärdikuid kiiritama
Irene Klotz teatab Discovery Channeli veebilehel, et NASA hakkab taas üle tüki aja oma katsetes kasutama pärdikuid, kelle abiga uuritakse, kuidas võib kosmiline kiirgus mõjutada astronautide tervist ja käitumist.For the new study, 18 to 28 squirrel monkeys will be exposed to a low dose of the type of radiation that astronauts traveling to Mars can expect to encounter. Scientists are particularly interested in studying how the radiation impacts the monkeys' central nervous systems and behaviors over time.
10/29/09
vaata veelTarkade Klubi kutsub teaduskohvikusse
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ERRi teadusleht teatab, et ajakiri Tarkade Klubi alustab järgmisel nädalal Tallinnas igakuise teaduskohvikute sarjaga, kus saab Eesti teadlastega vestelda päevakajalistel ja põnevatel teemadel. Esimene istung leiab aset teisipäeval, 3. novembril kell 18 galeriikohvikus aadressiga Toompuiestee 35 ning selle pealkiri "Masinad võtavad võimu" on inspireeritud peatselt ilmuva Tarkade Klubi novembrinumbri kaaneloost "Kapten Kompuuter", mis kõneleb, kuidas lennukite juhtimine on libisenud inimeste käest masinatele.
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vaata veelHalb autojuhtimisoskus on päritav?
LiveScience tutvustab väikesemahulist uuringut, mis viitab võimalusele, et kehv autojuhtimisoskus on päritava iseloomuga omadus.Such a small study would need to be replicated by other research, but here's what the researchers think is going on: The gene in question limits the availability of a protein called brain-derived neurotrophic factor (BDNF) during activity. This protein strengthens a person's memory by supporting communication among brain cells and keeping them in peak shape. When a person is engaged in a particular task, BDNF is secreted in the brain area connected with that activity to help the body respond. "These people make more errors from the get-go, and they forget more of what they learned after time away," said lead researcher Steven Cramer, neurology associate professor at the University of California, Irvine.
Kui palju universumeid on olemas?
Amanda Gefter tutvustab New Scientistis Stanfordi ülikooli uurijate Andrei Linde ja Vitaly Vanchurini arvutusi, mille kohaselt võib universumeid küll olemas olla lugematu hulk, ent inimaju piiratus võib kvantmaailmale omaste veidruste tõttu nende arvu oluliselt vähendada.According to Linde and Vanchurin, the total is about 101010,000,000 - that's a 10 raised to a number ending with 10 million zeros. Suddenly string theory's multiverse of 10500universes is looking rather claustrophobic. It might be, however, that this number is irrelevant, and that in a world ruled by quantum physics what matters is how many universes a single observer can distinguish.
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Varajaste inimeste suurimad müsteeriumid
LiveScience on kokku kogunud kümme suurimat mõistatust, mis ümbritsevad inimevolutsiooni algusaegu.Humans are unique among life on this planet, and much remains a mystery as to how we evolved. What steps came first? Why did we evolve this way and not that direction? Why are we the only human species left? What other paths might we have gone down in our evolution? And what directions might we go from here?
10/28/09
Kehv matemaatika kohtusaalis
Angela Saini tutvustab New Scientistis juhtumeid, kus lombakas või mitmetitõlgendatav matemaatiline statistika on mõjutanud kohtualuse süüdimõistmise võimalusi."Statistical errors happen astonishingly often," says Ray Hill, a mathematician at the University of Salford, UK, who has given evidence in several high-profile criminal cases. "I'm always finding examples that go unnoticed in evidence statements." The root cause is a sloppiness in analysing odds that can sully justice and even land innocent people in jail. With ever more trials resting on the "certainties" of data such as DNA matches, the problem is becoming more acute. Some mathematicians are calling for the courts to take a crash course in the true significance of the evidence put before them.
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USA sõdurid saavad kiivri sisse radari
Clay Dillow kirjutab Popular Science'i veebisaidil, et Ameerika Ühendriikide sõdurid võivad tulevikus saada oma kiivrisse radari, mis võimaldab neil tuvastada liikuvaid ja potentsiaalselt ohtlikke objekte kuni 25 meetri kauguselt ja peaaegu 360 kraadi ulatuses.The Helmet Mounted Radar Program aims to provide a near-360-degree field for Moving Target Indicator (MTI) radar sensors that is low-power and can detect a moving threat as far out as 25 meters. The sensor should be integrated into the combat helmet and weigh less than two-and-a-half pounds, with less than a pound mounted on the helmet itself. The system will also have to emit a low enough dose of radiated power to not affect the health of the soldiers wearing the helmets or friendlies operating nearby.
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