segunda-feira, 17 de outubro de 2011

OS GREGOS ERAM DEMAIS MESMO!

ANTIKYTHERA MECHANISM: MÁQUINA QUE CALCULAVA, COM PRECISÃO, ECLIPSES SOLARES HÁ MAIS DE DOIS MIL ANOS.


No primeiro vídeo, uma "brincadeira com legos, só para colocar no lugar quem se acha bom montando aviõezinhos. No segundo e no terceiro, o documentário da Nature sobre essa gigantesca descoberta.

 

sábado, 15 de outubro de 2011

DESCOBERTA DE HOT SPOTS DE MATERIAL RADIOATIVO ESPALHA MEDO MUITO ALÉM DE FUKUSHIMA


Fukushima 'hot spots' raise radiation fears
But experts see little threat from patches of heightened radioactivity.



Tokyo hotspot

A hot spot of radiation detected in Tokyo was traced to abandoned bottles of radium-226.
Sankei via Getty Images
The discovery of 'hot spots' of radioactive material is spreading fear far beyond the damaged Japanese nuclear power plant at Fukushima. But experts say that there is no threat from the small spots of increased radioactivity now being discovered in large-scale surveys.
On 12 October, officials reported finding 195 becquerels of strontium-90 on a rooftop in Yokohama, some 250 kilometres south from the Fukushima Daiichi plant. A day later, a citizen's group in Funabashi, Chiba Prefecture, about the same distance away, made radiation readings of 5.82 microsieverts per hour (μSv h–1) at a children's theme park. The same day, an inspection of Tokyo's Setagaya district turned up a narrow strip of pavement that seemed contaminated, at 3.35 μSv h–1. Officials later traced the Tokyo contamination to an abandoned house containing bottles of radium-226, a radioactive element once used in luminous paint.

Counting the risk

Since the Fukushima accident, the Japanese government's official safety limit for radiation exposure is 20 mSv per year, which corresponds roughly to a rate of 2.28 μSv h–1. Yet the newly discovered hot spots pose no threat to human health, says Geraldine Thomas, a radiation-health expert at Imperial College in London. Total radiation dose is measured by the strength of the radioactivity in a given area and the amount of time a person spends there. The small sizes of the hot spots make it all but inconceivable that anyone would receive 20 mSv, she says. Strontium-90 can cause bone cancer if ingested, but a small patch on a roof won't cause that problem, Thomas says. "These are minuscule amounts of radiation, but the population out there is terribly nervous."
Risk is about more than radiation readings, adds Christopher Clement, the scientific secretary of the International Commission on Radiation Protection in Ottawa, Canada, an independent international organization that provides guidance on safe levels of radiation. Its 'recommended' residual dose from a nuclear accident is between 20 and 100 mSv per year for the general population. The Japanese government has chosen the lower number as its official limit, Clement says, but "it's not a magical number by any means". Clement says that most scientists believe that receiving an additional 100 mSv of radiation over a prolonged period can raise the chance of dying of cancer by 0.5% (in the general population the chance of cancer being the cause of death is about 25%).

Under the limit


To reach that 100-mSv dose would require someone to be continuously exposed to the Japanese government's 20-mSv limit for 24 hours a day, seven days a week over a five-year period. A small amount of radioactive material on a rooftop or in a gutter poses little risk. "People don't sleep in that one spot in the gutter," he says.
Both Clement and Thomas say that more hot spots are likely to be discovered as citizens' groups, local authorities and government inspectors continue their surveys. And Clement says that everyone should be prepared for more false alarms like the one in Tokyo: "No matter where you go in the world, if you take a radiation instrument with you and look around, you'll eventually stumble across something that's above what the background for that area normally is," he says.

Published online 14 October 2011 | Nature | doi:10.1038/news.2011.593

quinta-feira, 28 de julho de 2011

PASSEIO GUIADO PELO CENTRO DE SÃO PAULO

Vídeo leve com algumas curiosidades sobre a cidade de São Paulo e sua relação com o café. Não se esqueça de buscar as referências das informações apresentadas antes de usá-las em seus trabalhos!

terça-feira, 28 de junho de 2011

PARA PODER EXPLICAR A FORMAÇÃO DE UM ARCO ÍRIS

08:00 Geração de cores a partir de dois slides p&b e um filtro vermelho
12:28 Cores a partir de preto e branco
21:36 Linda explicação sobre a formação de um arco-íris

quinta-feira, 16 de junho de 2011

CRIACIONISMO EM QUESTÃO

Se você ainda não sabe o que é criacionismo eis uma imperdível e divertida chance para preencher essa lacuna. Para falar de teoria da evolução há a necessidade de se conhecer as lendas que tentam contestá-la.
Primeiro lugar no festival de curtas de Berlim em 2008.

L'Animateur (The Animator) from Nick Hilligoss on Vimeo.

sábado, 11 de junho de 2011

EXPERIMENTO DA PRISÃO DE STANFORD E EXPERIMENTO DA OBEDIÊNCIA.

São as maçãs que são podres ou é o cesto que as está infectando?

Excelente palestra do Zimbardo, o responsável por um dos experimentos mais chocantes da história da psicologia, o Experimento da Prisão de Stanford. Para que não conhece, trata-se daquela história onde um grupo de estudantes são divididos em carcereiros e prisioneiros e lançados numa prisão-estúdio. Os resultados foram tão impressionantes que isso já virou filme.
Ele fala também de um também genial experimento sobre obediência e autoridade conduzido por Milgram, no qual um instrutor deveria aplicar choques no aprendiz a cada resposta errada. Os choques vão aumentando progressivamente até atingir uma descarga letal. Quantos representantes "normais" da sociedade você acha que mataram seus aprendizes?

Para os mais afoitos, no 09:49 min do vídeo começa a parte específica sobre o experimento da obediência e no 13º minuto começa o da prisão. Legendas em 24 línguas.

Aproveitem! E comentem!

Imagens fortes...

quinta-feira, 2 de junho de 2011

ENTRE RIOS


Entre Rios conta de modo rápido a história de São Paulo e como essa está totalmente ligada com seus rios. Muitas vezes no dia-a-dia frenético de quem vive São Paulo eles passam desapercebidos e só se mostram quando chove e a cidade pára. Mas não sinta vergonha se você não sabe onde encontram esses rios! Não é sua culpa! Alguns foram escondidos de nossa vista e outros vemos só de passagem, mas quando o transito pára nas marginais podemos apreciar seu fedor. É triste mas a cidade está viva e ainda pode mudar!



O video foi realizado em 2009 como trabalho de conclusão de Caio Silva Ferraz, Luana de Abreu e Joana Scarpelini no curso em Bacharelado em Audiovisual no SENAC-SP, mas contou com a colaboração de várias pessoas que temos muito a agradecer.



Direção:
Caio Silva Ferraz

Produção:
Joana Scarpelini

Edição:
Luana de Abreu

Animações:
Lucas Barreto
Peter Pires Kogl
Heitor Missias
Luis Augusto Corrêa
Gabriel Manussakis
Heloísa Kato
Luana Abreu

Camera:
Paulo Plá
Robert Nakabayashi
Tomas Viana
Gabriel Correia
Danilo Mantovani
Marcos Bruvic

Trilha Sonora:
Aécio de Souza
Mauricio de Oliveira
Luiz Romero Lacerda

Locução:
Caio Silva Ferraz

Edição de Som:
Aécio de Souza

Orientadores:
Nanci Barbosa
Flavio Brito

Orientador de Pesquisa:
Helena Werneck

Entrevistados:
Alexandre Delijaicov
Antônio Cláudio Moreira Lima e Moreira
Nestor Goulart Reis Filho
Odette Seabra
Marco Antonio Sávio
Mario Thadeu Leme de Barros
José Soares da Silva

quarta-feira, 1 de junho de 2011

domingo, 8 de maio de 2011

VÍDEOS - ROTEIRO DOS BANDEIRANTES


DVD Porto Feliz Roteiro dos Bandeirantes - A ORIGEM DO POVOADO



DVD Porto Feliz Roteiro dos Bandeirantes - O RIO TIETÊ



DVD Porto Feliz Roteiro dos Bandeirantes -  O MONUMENTO DAS MONÇÕES





DVD Porto Feliz Roteiro dos Bandeirantes - O MUSEU DAS MONÇÕES





DVD Porto Feliz Roteiro dos Bandeirantes - A SEMANA DAS MONÇÕES





DVD Porto Feliz Roteiro dos Bandeirantes - A IGREJA MATRIZ




DVD Porto Feliz Roteiro dos Bandeirantes - DESENVOLVIMENTO ECONÔMICO





DVD Porto Feliz Roteiro dos Bandeirantes - MUSEU PAULISTA E PORTO FELIZ








ARTIGO RELACIONADO AO PETAR 14

domingo, 1 de maio de 2011

UM AUXÍLIO NA ESCOLHA DE FILMES A SEREM PASSADOS NAS VIAGENS AO PETAR

ARTIGO RELACIONADO AO PETAR 13


Vale a pena dar uma lida para inspirar a fala sobre evolução nas nossas atividades cavernículas no PETAR. Quem quiser o artigo completo manifeste-se através do mural de comentários desta página, pois o acesso é restrito.



Genetic basis of eye and pigment loss in the cave crustacean, Asellus aquaticus



  1. aDepartment of Molecular and Cell Biology, Center of Integrative Genomics, and Department of Integrative Biology, University of California, Berkeley, CA 94720-3200; and
  2. bBiotechnical Faculty, Department of Biology, University of Ljubljana, SI-1000 Ljubljana, Slovenia
  1. Edited* by Clifford J. Tabin, Harvard Medical School, Boston, MA, and approved February 25, 2011 (received for review September 15, 2010)

Abstract

Understanding the process of evolution is one of the great challenges in biology. Cave animals are one group with immense potential to address the mechanisms of evolutionary change. Amazingly, similar morphological alterations, such as enhancement of sensory systems and the loss of eyes and pigmentation, have evolved multiple times in a diverse assemblage of cave animals. Our goal is to develop an invertebrate model to study cave evolution so that, in combination with a previously established vertebrate cave system, we can address genetic questions concerning evolutionary parallelism and convergence. We chose the isopod crustacean, Asellus aquaticus, and generated a genome-wide linkage map for this species. Our map, composed of 117 markers, of which the majority are associated with genes known to be involved in pigmentation, eye, and appendage development, was used to identify loci of large effect responsible for several pigmentation traits and eye loss. Our study provides support for the prediction that significant morphological change can be mediated through one or a few genes. Surprisingly, we found that within population variability in eye size occurs through multiple mechanisms; eye loss has a different genetic basis than reduced eye size. Similarly, again within a population, the phenotype of albinism can be achieved by two different genetic pathways—either by a recessive genotype at one locus or doubly recessive genotypes at two other loci. Our work shows the potential of Asellus for studying the extremes of parallel and convergent evolution—spanning comparisons within populations to comparisons between vertebrate and arthropod systems.

Verifique a fonte aqui.



sexta-feira, 18 de março de 2011

FAST FACTS ABOUT RADIATION FROM THE FUKUSHIMA DAIICHI REACTORS


Elevated radiation levels have been detected at and around the stricken nuclear power station in Japan, but the Chernobyl accident remains far more catastrophic

Radiation symbolImage: WIKIMEDIA COMMONS
Since a magnitude 9.0 earthquake rocked Japan and set loose a massive tsunami March 11, the Tokyo Electric Power Co. (TEPCO) has been scrambling to avert a nuclear disaster at its hardest hit plant. The Fukushima Daiichi nuclear power station, home to six nuclear reactors, has witnessedexplosions at three reactors and a fire in a spent-fuel pool at a fourth. At two reactors, unit Nos. 2 and 3, the vessels containing the nuclear material are suspected to be compromised.

A handful of plant workers remain on the site, implementing emergency cooling measures at the stricken, overheating reactors. Radiation levels have fluctuated wildly during the crisis, and the extent to which the workers' health has been endangered may not become apparent for years. But so far, the radiation releases have been limited compared with the 1986 Chernobyl disaster in Ukraine, an explosive event that caused dozens of cases of fatal radiation poisoning among plant workers and that has been implicated in thousands of thyroid cancer diagnoses in the years that followed. (Nuclear fission of uranium fuel produces radioactive iodine, which gathers in the thyroid gland.) As many nuclear experts have noted, the Fukushima reactors are better designed than the failed Chernobyl reactor.

Below are some facts and figures about the radiation hazard posed by the Fukushima breakdown and how it compares with other nuclear accidents in history. Many of the figures are measured in millisieverts, an international unit of radiation dosage. (One sievert is equal to 100 rems, which is a dosage unit of x-ray and gamma-ray radiation exposure; one millisievert is 0.1 rem.)

Radiation dose at the boundary of the Fukushima Daiichi nuclear power station on March 16: 1.9 millisieverts (mSv) per hour

Peak radiation dose measured inside Fukushima Daiichi on March 15:400 mSv per hour

Maximum allowable exposure for U.S. radiation workers: 50 mSv per year

Average exposure of U.S. residents from natural and man-made radiation sources: 6.2 mSv per year

Estimated total exposure at the boundary of the Three Mile Island site in Pennsylvania during the 1979 accident there: one mSv or less

Average total radiation dose to the 114,500 individuals evacuated during the 1986 Chernobyl disaster: 31 mSv

Half-life of iodine 131, a dangerous radioactive isotope released in nuclear accidents: eight days

Half-life of cesium 137, another major radionuclide released in nuclear accidents: 30 years

Decay products of iodine 131 and cesium 137: both emit gamma rays and beta particles (electrons or positrons)

Amount of nuclear fuel in Chernobyl reactor No. 4 that exploded in 1986:190 metric tons

Amount of nuclear fuel and fission by-products released into the atmosphere during Chernobyl disaster: 25 to 57 metric tons

Approximate amount of nuclear fuel in each crippled Fukushima Daiichi reactor: 70 to 100 metric tons

Sources: Japan Atomic Industrial Forum, International Atomic Energy Agency, U.S. Nuclear Regulatory Commission, National Council on Radiation Protection and Measurements, U.S. Environmental Protection Agency, United Nations Scientific Committee on the Effects of Atomic Radiation, National Institute of Standards and Technology, Nuclear Energy Institute