sexta-feira, 31 de julho de 2009
quinta-feira, 30 de julho de 2009
in Planet Thoughts
Only 14 of the 54 oil producing nations in the world are still increasing their oil production. The era of cheap oil is definitively over.
|Country||Peak Prod.||2008 Prod.||% Off Peak||Peak Year|
|Other Middle East||79||33||-58%||1970|
|Trinidad & Tobago||230||149||-35%||1978|
|Other Europe & Eurasia||762||427||-44%||1986|
|Other Asia Pacific||276||237||-14%||1993|
|Rep. of Congo (Brazzaville)||266||249||-6%||1999*|
|Other S. & Cent. America||153||138||-10%||2003*|
|Saudi Arabia||11114||10846||-2%||2005 / Growing|
|Canada||3320||3238||-2%||2007 / Growing|
|Algeria||2016||1993||-1%||2007 / Growing|
|Equatorial Guinea||368||361||-2%||2007 / Growing|
|United Arab Emirates||2980||2980||-||Growing|
|Peaked / Flat Countries Total||-||49597||-||60.6% of world oil production|
|Growing Countries Total||-||32223||-||39.4% of world oil production|
- Russian Federation - Russia's oil production collapsed by the early 90's as the Soviet Union collapsed, but despite a decade of growth, Russia's own oil execs don't think the old peak can be surpassed.
- India's production appeared to plateau in 1995, and has stayed within a steady range since. The EIA forecasts Indian oil production to remain flat or decline slightly in the near future.
- Republic of Congo (Brazzaville) hit a production plateau in 1998, though current production is still very close to 1999 peak levels.
- Other Central & South America - The remaining countries of the Americas hit a production peak in 2003, though it's still too soon to know if this will be final peak.
- Malaysia has been on a production plateau since 1995, and the EIA projects flat or falling production.
- Other Africa - Oil production in much of Africa is potentially impacted by above-ground constraints, so it's definitely possible that production will rise here. It will rise from a low base of only 50,000 bpd however, and may not have much impact on total world production.
- Nigeria is impacted by domestic insurgencies in its oil-producing regions, and may be able to lift production if the political situation improves.
- Chad's oil production history is too short to definitively identify a peak in production, but the drop-off since 2005 has been dramatic.
- Italy has been on a production plateau for over 10 years, and it's unlikely that a mature economy is significantly under-exploiting its resource potential.
- Ecuador's production grew rapidly until 2004, but has leveled off and declined somewhat since then.
quarta-feira, 29 de julho de 2009
In a society where 94 percent* of the electrical energy generated is generated using fossil fuels, ordinary citizens using electricity are not to blame for anthropogenic greenhouse gas emissions.
* Ref: Relatório Estatístico dos Consumos Energéticos 2009 da IEA http://www.iea.org/Textbase/stats/surveys/mes.pdf
Ideia entretanto também referida em Calor: Como Impedir o Planeta de Arder, de George Monbiot
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Turn Up the Heat
terça-feira, 28 de julho de 2009
Em praticamente todos os seres vivos, à excepção dos Mamíferos, o sistema reprodutor combinado com o sistema digestivo e urinário, desembocam todos num único tubo com contacto para o exterior, a cloaca. Há cerca de 150 milhões de anos, contudo, uma provável alteração nas funções do oviducto (aparecimento do útero, com funções de desenvolvimento interno do embrião) devido, muito provavelmente, a modificações epigenéticas, terá levado ao aparecimento de toda uma nova estrutura: a vagina.
Evolution of the mammalian vagina [originalmente aqui]
Q: What unique organ is found only in mammals, but not in fish, amphibians, reptiles, or birds?
The title and that little picture to the left ought to be hint enough, but if not, read on.
A: The vagina. Aren't we lucky?
There's an old joke going around about poor design: what kind of designer would route the sewer pipes right through the center of the entertainment center? It's a good point. It doesn't make sense from a design standpoint to have our reproductive and excretory systems so intimately intermingled, but it does make a heck of a lot of sense from a purely historical point of view. In a sense, reproduction is an excretory function: we are shedding gametes produced internally, and we already have a perfectly good set of pipes running from our insides to the outside, so why not use them? It's just that in our lineage, which has specialized in giving great care to our gametes and zygotes, that plumbing has become increasingly elaborate, and that part of the system that was once just a convenient throughway has become a destination and a long-term residence in its own right.
Development tells us part of the story. The reproductive and urinary tracts are all tangled together in early development, arising together from two pairs of ducts, the Müllerian and Wolffian ducts, which are modified in complex ways to form a series of kidneys (we keep only the last one, the metanephros), one set of pathways for the male testes, and yet another set for the female ovaries.
In non-therian mammals, all of these complicated pipes have one common destination, a single outlet to the external world: the cloaca. Cloaca is Latin for sewer, and it is appropriately named. The terminus of the large intestine is here, as well as the ends of the ureters from the kidneys and the ducts from the ovaries or testes. Everything gets dumped in to the cavity of the cloaca, making a nice stew of feces, urine, and sperm or eggs. Mmm-mmm. The cloaca is the grey cylinder at the bottom of figure A, below, in the first three organisms, amphibians, birds/reptiles, and monotremes (my apologies for the murkiness of the image; it's the best copy I have).
The fundamental organization of the reproductive part of the vertebrate urogenital tract is straightforward: it's a tube with a funnel at one end that captures eggs released by the ovary, and conducts them to an external orifice. Along the way, cells lining the tube secrete useful products like albumin and yolk, and deposit a shell, and may act to temporarily store the egg before its final release.
Marsupial and placental mammals have dispensed with most of those functions, and expanded on others. One part of the oviduct has acquired a richly vascularized epithelium and specializations for investing and nurturing a resident embryo, becoming a uterus. That's an amazing and innovative function in itself, but in addition, it has formed a new, separate channel, the vagina. The vagina is an entirely new structure, which has no homolog in amphibians or reptiles.
That is an interesting observation. It's a wholly original structure that arose sometime after the monotreme-marsupial split, an evolutionary novelty. How did that happen? How can we study a unique event that occurred over 150 million years ago?
Wagner and Lynch have a proposal to answer both questions. The general mechanism for generating novel structures is evo-devo orthodoxy:
- An epigenetic side effect of other evolutionary changes in the body leading to a novel physical structure in the organisms.
- The genetic consolidation and individuation of the novel structure.
(Note that this proposes phenotype before genotype, which is somewhat heretical for neodarwinism. It shouldn't trouble the evo-devo gang in the slightest, of course.)
How to study such a process from the past?
The basic assumption of a molecular evolutionary approach to the study of evolutionary novelties is that changes in developmental regulation have left traces in the molecular structure of the genome and a comparative study of genomic structures should be able to identify genetic changes coincidental with a phenotypic novelty. (emphasis mine)
That process of consolidation and individuation would have left detectable scars in the genome—the genes involved would have acquired changes necessary to fix the phenotype in the population. Again, as we'd expect from the evo-devo perspective, those changes would have been made to the regulatory genes that control tissue-specific gene expression. What genes should we examine? Let's look at the therian organs of interest, and here are some likely candidates: the HoxA genes that have region-specific domains in the female reproductive tract.
The HoxA-9 through HoxA-13 genes are expressed in order along the length of the embryonic Müllerian duct, and also continue to be expressed in adulthood; so the cells of the vagina are all expressing HoxA-13, while the cells of the cervix all have HoxA-11 turned on (for some reason, I find that to be a wonderful piece of knowledge, and I just have to say…Hooray for HoxA-13! It has just become my favorite Hox gene.)
So the question is whether there is any evidence that these particular Hox genes have signs of any set of changes that are associated with particular transitions in vertebrate evolution—in particular, are there differences that can be traced to the transition between monotremes and the theria, and between the placentals and marsupials. The answer seems to be yes: the diagram to the right is a measure of the number of synonymous to nonsynonymous changes in HoxA-11, which is an indicator of the selective pressures that have shaped the gene.
Furthermore, they've identified where these changes have occurred, and they are not in the homeodomain (the part of the protein that binds to specific sequences in the DNA, but in the amino terminal end.
The 3-D models below show where the relevant amino acids (in yellow) end up in the folded protein. The interesting thing here is that regulatory proteins don't just interact with each other, but also with other regulatory proteins that are simultaneously binding. It's a whole chain of interactions—regulatory proteins binding to the DNA, and also binding between each other in a complex called the enhancersome—that determines the level of expression of a particular gene.
There is a great deal left to be done. Hox genes are rather high up the chain of regulatory genes, so there are many more genes downstream that have to be puzzled out. We also are a long ways from figuring out how these patterns of gene expression define the morphogenetic processes that create this lovely novel structure, the vagina. The important thing, though, is that there are these questions waiting to be answered—the investigators have a research program.
We propose that a research program to explain evolutionary novelties has to focus on the question of whether novel characters arise through the evolution of novel regulatory links among developmental genes. We further propose that a detailed analysis of the evolution of developmental genes involved in the development of a derived, novel character can reveal molecular changes that could be causally involved in the origin of evolutionary novelties. The case study presented here suggests that the statistical methods of molecular evolution are strong enough to provide specific hypothesis for experimental test. The success of this research program will depend on the ability to connect the patterns of molecular evolution with the functional role of these molecular changes.
That's the cool thing about evolutionary biology: exciting questions, titillating ancestors, and the promise of tools to answer more.
Lynch VJ, Roth JJ, Takahashi K, Dunn CW, Nonaka DF, Stopper GF, Wagner GP (2004) Adaptive evolution of HoxA-11 and HoxA-13 at the origin of the uterus in mammals. Proc Biol Sci. 271(1554):2201-7. [pdf]
Wagner GP, Lynch VJ (2005) Molecular evolution of evolutionary novelties: the vagina and uterus of therian mammals. J Exp Zoolog B Mol Dev Evol. [Epub ahead of print]
Cifelli RL, Davis BM (2003) Marsupial Origins. Science 302:1899-1900.
segunda-feira, 27 de julho de 2009
Embora em inglês, quem melhor para abordar a evolução do pénis por PZ Myers (biólogo e Professor Associado da Universidade de Minnesota, Morris).
Os pénis embrionários tiveram uma história complexa. Eles evoluíram independentemente várias vezes, e talvez o mais preocupante para o ego masculino, que tenham sido perdidos secundariamente, pelo menos, algumas vezes. E cada vez que eles têm evoluído, as evoluções convergem numa solução morfológica notavelmente semelhante.
What, then, can we conclude if we observe convergence at more than one anatomical or functional level? Multiple levels of convergence could imply that there are more constraints on the system—that there are fewer possible anatomical designs that successfully meet the selective regime. Therefore, if there is only one way to solve the problem imposed by the selective regime, we will see convergence at more levels than if many equally successful anatomies can evolve.
If this hypothesis is true, the evidence from mammals and turtles suggests that the amniotes that have evolved inflatable penises have been subjected to an extremely restrictive selective regime. Penile convergence in mammals and turtles does not stop at gross functional similarity; they have converged on a single anatomical design down to the level of specific collagen fiber arrangements. The differences in penile collagen fiber layering that exist between mammals and turtles do not, as of yet, seem to have any functional effect on penile stiffness. It may be that the way the axial orthogonal array is put together is less critical to the problem of increasing penile flexural stiffness than the presence of the array itself.
domingo, 26 de julho de 2009
sábado, 25 de julho de 2009
São originalmente cinco mil entrevistas filmadas em 75 países por seis realizadores que foram ao encontro dos Outros como Tu!
[Saber mais em Futura-Sciences]
Consultar também esta postagem no BioTerra.
sexta-feira, 24 de julho de 2009
- Uma brilhante compilação de dados feitas por este brilhante blogue da Dinamarca, com fotos muito criativas (como esta) relembrando os perigos de condução e dos riscos ambientais do uso excessivo do automóvel - Driving Kills - Health Warnings
- Todas as postagens do Bioterra com a etiqueta Bicicleta
Eis uma selecção (espectacular) de blogues e sítios dedicados à cultura da bicicleta [e não só], também existente no referido blogue
[AUSTRALIA] CYCLING RESOURCE CENTRE
[AUSTRALIA] GREEN WITH A GUN [NOT BIKES BUT COOL]
[AUSTRIA] CYCLING IS GOOD FOR YOU
[CANADA] DAVID SUZUKI FOUNDATION
[CANADA] MOMENTUM PLANET
[CANADA] ROULER Á VÉLO
[CATALONIA] AMICS DE LA BICI
[DENMARK] COPENHAGEN CYCLE CHIC!
[DENMARK] COPENHAGEN: CITY OF CYCLISTS
[DENMARK] COPENHAGEN: FREE CITY BIKE PROGRAMME
[DENMARK] COPENHAGENIZE CONSULTING
[DENMARK] LARRY VS HARRY BLOG
[DENMARK] VISIT DENMARK ON BIKE
[EASTERN EUROPE] EST GOES EAST
[EU] EUROPEAN CYCLIST'S FEDERATION
[EU] BYPAD - BETTER URBAN CYCLING
[EU] GREEN PAPER ON URBAN TRANSPORT
[FRANCE] FUBICY - FEDERATION OF BIKE USERS
[HELMETS] BICYCLE HELMET RESEARCH FOUNDATION
[HELMETS] BICYCLE SAFE
[HELMETS] NO HELMET LAW
[ITALY] I LIKE BIKE
[ITALY] FEDERATION OF FRIENDS OF THE BIKE
[JAPAN] JAPAN CYCLING NAVIGATOR
[JAPAN] JAPANESE BICYCLING PROMOTION INSTITUTE
[NETHERLANDS] CYCLING IN THE NETHERLANDS .PDF
[NETHERLANDS] DAVID HEMBROW'S BLOG
[NEW ZEALAND] URBAN BICYCLES
[UK] BIKE DARLINGTON
[UK] COLCHESTER CYCLING CAMPAIGN
[UK] CTC - NATIONAL CYCLIST ASSOC.
[UK] CYCLING EDINBURGH
[UK] LONDON CYCLING CAMPAIGN
[UK] QUICKRELEASE.TV BY CARLTON REID
[UK] THE BIKE SHOW
[USA] AN ADVENTURE CALLED BICYCLING
[USA] BICYCLE SAFE
[USA] BIKE LEMMING
[USA] BIKE PORTLAND
[USA] BIKE SNOB
[USA] LEAGUE OF BICYCLING VOTERS
[USA] ONE STREET.ORG
[USA] SUSTAINABLE FLATBUSH
Bicicletas de Bambu made in Gana
quinta-feira, 23 de julho de 2009
6.000 entrevistas realizadas, 65 paíse visitados, 4.500 horas de entrevistas filmadas, foi o magnífico trabalho de Yann Arthus-Bertrand
quarta-feira, 22 de julho de 2009
terça-feira, 21 de julho de 2009
segunda-feira, 20 de julho de 2009
Curiosamente, os apelos em tempo de paz para os indivíduos fazerem qualquer pequeno sacrifício na taxa de aumento do seu nível de vida para ser menos eficiente que os apelos, durante o tempo de guerra, para que dêem a sua vida.[página 31]
domingo, 19 de julho de 2009
Quadro completamente interactivo. Se tiver dificuldade de navegação, clique aqui.Num momento em que o turismo de voluntariado começa a ser desejado como forma de preencher mais produtivamente o tempo de férias, eis uma óptima sugestão.
Nota: Antes de escolher pergunte a si mesmo: quero mesmo viajar de avião? Pense primeiro na redução da sua pegada de carbono. Obrigado.
sábado, 18 de julho de 2009
Tradução em espanhol disponível em Stralunato
Blogging is one of the easiest ways you can help a charity or cause you feel passionate about. Almost everyone has an outlet for blogging these days -- whether that means a site running WordPress, an account at LiveJournal, or a blog on MySpace or Facebook. By writing about issues you're passionate about, you're helping to spread awareness among your social circle. Because your friends or readers already trust you, what you say is influential.
Recently, a group of green bloggers banded together to raise individual $1 donations from their readers. The beneficiaries included Sustainable Harvest, Kiva, Healthy Child, Healthy World, Environmental Working Group, and Water for People. The blog-driven campaign included voting to determine how the funds would be distributed between the charities. You can read about the results here. You should also consider taking part in Blog Action Day, a once a year event in which thousands of blogs pledge to write at least one post about a specific social cause (last year it was fighting poverty). Blog Action Day will be on October 15 this year.
2. Share Stories with Friends
Another way to spread awareness among your social graph is to share links to blog posts and news articles via sites like Twitter, Facebook, Delicious, Digg, and even through email. Your network of friends is likely interested in what you have to say, so you have influence wherever you've gathered a social network. You'll be doing charities you support a great service when you share links to their campaigns, or to articles about causes you care about.
When your charities tweet or post information about a campaign or a cause, statistics or a link to a good article, consider retweeting that post on Twitter, liking it on Facebook, or blogging about it. Following charities on social media sites is a great way to keep in the loop and get updates, and it's a great way to help the charity increase its reach by spreading information to your friends and followers. You can follow the Summer of Social Good Charities:
Oxfam America (Twitter, Facebook, MySpace, Flickr, YouTube) The Humane Society (Twitter, Facebook, YouTube, MySpace, Flickr) LIVESTRONG (Twitter, Facebook, MySpace, YouTube, Flickr) WWF (Twitter, Facebook, YouTube, Flickr)
4. Support Causes on Awareness Hubs
Another way you can show your support for the charities you care about is to rally around them on awareness hubs like Change.org, Care2, or the Facebook Causes application. These are social networks or applications specifically built with non-profits in mind. They offer special tools and opportunities for charities to spread awareness of issues, take action, and raise money.
It's important to follow and support organizations on these sites because they're another point of access for you to gather information about a charity or cause, and because by supporting your charity you'll be increasing their overall reach. The more people they have following them and receiving their updates, the greater the chance that information they put out will spread virally.
5. Find Volunteer Opportunities
Using social media online can help connect you with volunteer opportunities offline, and according to web analytics firm Compete, traffic to volunteering sites is actually up sharply in 2009. Two of the biggest sites for locating volunteer opportunities are VolunteerMatch, which has almost 60,000 opportunities listed, and Idealist.org, which also lists paying jobs in the non-profit sector, in addition to maintaining databases of both volunteer jobs and willing volunteers.
For those who are interested in helping out when volunteers are urgently needed in crisis situations, check out HelpInDisaster.org, a site which helps register and educate those who want to help during disasters so that local resources are not tied up directing the calls of eager volunteers. Teenagers, meanwhile, should check out DoSomething.org, a site targeted at young adults seeking volunteer opportunities in their communities.
6. Embed a Widget on Your SiteMany charities offer embeddable widgets or badges that you can use on your social networking profiles or blogs to show your support. These badges generally serve one of two purposes (or both). They raise awareness of an issue and offer up a link or links to additional information. And very often they are used to raise money. Mashable's Summer of Social Good campaign, for example, has a widget that does both. The embeddable widget, which was custom built using Sprout (the creators of ChipIn), can both collect funds and offer information about the four charities the campaign supports.
7. Organize a TweetupYou can use online social media tools to organize offline events, which are a great way to gather together like-minded people to raise awareness, raise money, or just discuss an issue that's important to you. Getting people together offline to learn about an important issue can really kick start the conversation and make supporting the cause seem more real. Be sure to check out Mashable's guide to organizing a tweetup to make sure yours goes off without a hitch, or check to see if there are any tweetups in your area to attend that are already organized.
8. Express Yourself Using VideoAs mentioned, blog posts are great, but a picture really says a thousand words. The web has become a lot more visual in recent years and there are now a large number of social tools to help you express yourself using video. When you record a video plea or call to action about your issue or charity, you can make your message sound more authentic and real.
You can use sites like 12seconds.tv, Vimeo, and YouTube to easily record and spread your video message. Last week, the Summer of Social Good campaign encouraged people to use video to show support for charity. The #12forGood campaign challenged people to submit a 12 second video of themselves doing something for the Summer of Social Good.
That could be anything, from singing a song to reciting a poem to just dancing around like a maniac -- the idea was to use the power of video to spread awareness about the campaign and the charities it supports. If you're more into watching videos than recording them, Givzy.com enables you to raise funds for charities like Unicef and St. Jude's Children's Hospital by sharing viral videos by e-mail.
9. Sign or Start a PetitionThere aren't many more powerful ways to support a cause than to sign your name to a petition. Petitions spread awareness and, when successfully carried out, can demonstrate massive support for an issue. By making petitions viral, the social web has arguably made them even more powerful tools for social change.
There are a large number of petition creation and hosting web sites out there. One of the biggest is The Petition Site, which is operated by the social awareness network Care2, or PetitionOnline.com, which has collected more than 79 million signatures over the years. Petitions are extremely powerful, because they can strike a chord, spread virally, and serve as a visual demonstration of the support that an issue has gathered.
Social media fans will want to check out a fairly new option for creating and spreading petitions: Twitition, an application that allows people to create, spread, and sign petitions via Twitter.
10. Organize an Online EventSocial media is a great way to organize offline, but you can also use online tools to organize effective online events. That can mean free form fund raising drives, like the Twitter-and-blog-powered campaign to raise money for a crisis center in Illinois last month that took in over $130,000 in just two weeks. Or it could mean an organized "tweet-a-thon" like the ones run by the 12for12k group, which aims to raise $12,000 each month for a different charity.
In March, 12for12k ran a 12-hour tweet-a-thon, in which any donation of at least $12 over a 12 hour period gained the person donating an entry into a drawing for prizes like an iPod Touch or a Nintendo Wii Fit. Last month, 12for12k took a different approach to an online event by holding a more ambitious 24-hour live video-a-thon, which included video interviews, music and sketch comedy performances, call-ins, and drawings for a large number of prizes given out to anyone who donated $12 or more.