Ritasakano - Outubros
More Posts from Ritasakano and Others
Fofis!!!
Mohommah G. Baquaqua
“’Que aqueles ‘indivíduos humanitários’ que são a favor da escravidão se coloquem no lugar do escravo no porão barulhento de um navio negreiro, apenas por uma viagem da África à América, sem sequer experimentar mais que isso dos horrores da escravidão: se não saírem abolicionistas convictos, então não tenho mais nada a dizer a favor da abolição.’ As palavras são de Mahommah Gardo Baquaqua, ex-escravo nascido no Norte da África no início do século XIX e que trabalhou no Brasil antes de fugir das amarras da servidão em Nova York, em 1847. O trecho consta do livro “An interesting narrative. Biography of Mahommah G. Baquaqua” (“Uma interessante narrativa: biografia de Mahommah G. Baquaqua”, em tradução livre), lançado assim mesmo, em inglês, pelo próprio ex-escravo, em Detroit, no ano de 1854, em plena campanha abolicionista nos EUA. A obra jamais foi traduzida para o português, permanecendo desconhecida do público brasileiro.
Fonte: http://www.bocadaforte.com.br/reportagens/baquaqua-a-auto-biografia-de-um-escravo.html
Interessante!!!
Everyone pitches in for protein synthesis! Here are three types of RNA helping your cells make proteins. Be sure to check out all our science GIFs here for your studyblrs, teacher websites, presentations, or general amusement! Just please keep our name on there and don’t sell them! :D
Why are some insects so shiny and iridescent?
First here’s a post I answered on HOW insects form shiny or iridescent exoskeletons. It’s always good to know the answer to how because it can give context to the why. So why are some insects iridescent or shiny?
This can be split into two main categories; communicative functions and non-communicative.
COMMUNICATION
1. Mate Selection
While insects tend to use chemical communication more as a means of attracting potential mates colouration can however play a significant role in mate selection in a number of ways.
Honest signalling - in which the colouration reveals the quality of the individual as these colourations are costly to produce. Therefore only individuals that are high-quality are able to afford the cost of producing these signals (in this case the iridescence or shiny colouration)
Example:
A study (Fitzstephens & Getty, 2000) found that male Calopteryx maculata (Black-winged damselfly) with higher fat stores had a much bluer iridescent colouration compared to males on low fat diets.
Amplifier traits - iridescent / shiny colours may be used to amplify the differences in the signals of quality (however no studies have directly focused if this is a function of iridescence)
Sensory drives - iridescent colouration was favoured due to being more effective in signalling in certain ecological environments
Receiver Bias - females (or in rare cases the males or hermaphrodites) as the receivers may have favoured certain iridescent colouration due to being better received by their sensory system therefore resulting in the evolution of this colouration
2. Species Recognition
Man species use iridescent / shiny colouration in order to identify members of their own species! As simple as that!
Example:
Colias eurytheme (orange sulfur butterfly) use UV iridescence to communication with conspecifics
3.Agonistic interactions
Iridescense / shiny colouration may be used in intrasexual encounters; mostly male-male agonistic encounters and can be used as a territorial signal.
4.flocking behaviour
Can help insects that school together facilitate their orientation or direction within their schools / flocks. This is seen in many aquatic species of fish and even squid.
5. Predation avoidance
Iridescense / shiny colouration can be used to order to actually avoid predation! Although at first glance you’d assume this would make them more visible, this isn’t always the case.
Mimicry / camouflage - insects can avoid predation by mimicking objects, leaves, raindrops, other harmful species or even by blending into the background
Examples:
A number of iridescent jumping spider species (Salticidae); such as Brettus adonis in this study (Jackson & Hallas 1986) were found to mimic raindrops to avoid predation
The iridescent green leaf beetles such as the (Dogbane Leaf Beetle, Chrysochus auratus) similarity use their iridescence colouration to mimic dew on leaves.
Species like tiger beetles ( Cicindelinae) even use their iridescence to create an unsaturated appearance that allow them to blend into their envrionment (Schultz 1986, 2001)
Warning colouration - insects may use their colouration to communicate their toxicity or unpalatability serving as aposematic warning.
Example:
Panamanian tortoise beetle (Charidotella egregia) that change from gold to red when disturbed by predators(Vigneron et al. 2007).
Startle displays - some species will use their iridescence colouration to create a flash that may startle potential predators long enough for them to escape due to the way in which the iridescence reflects light.
Example:
The tiger beeltes again! Some of them have bright colouration like below that they use as startle defenses against predators (Sargent 1990).
NON-COMMUNICATION
1. Thermoregulation
There’s much debate over whether Iridescense / shiny colouration has any function in either heat absorption or dispersion.
Some found evidence that the structures used to created iridescense / shiny colouration acted as heat collectors, like in the wings of butterflies ( Miaoulis & Heilman 1998). However other’s have found no evidence of thermoregulation in tiger beetles Schultz & Hadley (1987).
2.Friction reduction
iridescense structures may reduce the friction in burrowing insects
Example: Carabid Beetles (Brachininae) (Seago et al. 2009).
These are just some of the proposed and studied functions of iridescense and shiny colouration in insects, there are more that aren’t as well studied or understood just yet!
More reading:
Doucet S, Meadows M 2009, ‘Iridescence: a functional perspective’, Journal of the Royal Society Interface, vol.6, no.2, pp.115–132
Meadows M, Butler M, Morehouse N, Taylor L, Toomey M, McGraw K, Rutowski R 2009, ‘Iridescence: views from many angles’, Journal of the Royal Society Interface, vol.6, pp.203–211
Do not go where the path may lead, go instead where there is no path and leave a trail. —Ralph Waldo Emerson
13 Reasons to Have an Out-of-This-World Friday (the 13th)
1. Not all of humanity is bound to the ground
Since 2000, the International Space Station has been continuously occupied by humans. There, crew members live and work while conducting important research that benefits life on Earth and will even help us eventually travel to deep space destinations, like Mars.
2. We’re working to develop quieter supersonic aircraft that would allow you to travel from New York to Los Angeles in 2 hours
We are working hard to make flight greener, safer and quieter – all while developing aircraft that travel faster, and building an aviation system that operates more efficiently. Seventy years after Chuck Yeager broke the sound barrier in the Bell X-1 aircraft, we’re continuing that supersonic X-plane legacy by working to create a quieter supersonic jet with an aim toward passenger flight.
3. The spacecraft, rockets and systems developed to send astronauts to low-Earth orbit as part of our Commercial Crew Program is also helping us get to Mars
Changes to the human body during long-duration spaceflight are significant challenges to solve ahead of a mission to Mars and back. The space station allows us to perform long duration missions without leaving Earth’s orbit.
Although they are orbiting Earth, space station astronauts spend months at a time in near-zero gravity, which allows scientists to study several physiological changes and test potential solutions. The more time they spend in space, the more helpful the station crew members can be to those on Earth assembling the plans to go to Mars.
4. We’re launching a spacecraft in 2018 that will go “touch the Sun”
In the summer of 2018, we’re launching Parker Solar Probe, a spacecraft that will get closer to the Sun than any other in human history. Parker Solar Probe will fly directly through the Sun’s atmosphere, called the corona. Getting better measurements of this region is key to understanding our Sun.
For instance, the Sun releases a constant outflow of solar material, called the solar wind. We think the corona is where this solar wind is accelerated out into the solar system, and Parker Solar Probe’s measurements should help us pinpoint how that happens.
5. You can digitally fly along with spacecraft…that are actually in space…in real-time!
NASA’s Eyes are immersive, 3D simulations of real events, spacecraft locations and trajectories. Through this interactive app, you can experience Earth and our solar system, the universe and the spacecraft exploring them. Want to watch as our Juno spacecraft makes its next orbit around Juno? You can! Or relive all of the Voyager mission highlights in real-time? You can do that too! Download the free app HERE to start exploring.
6. When you feel far away from home, you can think of the New Horizons spacecraft as it heads toward the Kuiper Belt, and the Voyager spacecraft are beyond the influence of our sun…billions of miles away
Our New Horizons spacecraft completed its Pluto flyby in July 2015 and has continued on its way toward the Kuiper Belt. The spacecraft continues to send back important data as it travels toward deeper space at more than 32,000 miles per hour, and is ~3.2 billion miles from Earth.
In addition to New Horizons, our twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing on their more-than-37-year journey since their 1977 launches, they are each much farther away from Earth and the sun than Pluto. In August 2012, Voyager 1 made the historic entry into interstellar space, the region between the stars, filled with material ejected by the death of nearby stars millions of years ago.
7. There are humans brave enough to not only travel in space, but venture outside space station to perform important repairs and updates during spacewalks
Just this month (October 2017) we’ve already had two spacewalks on the International Space Station…with another scheduled on Oct. 20.
Spacewalks are important events where crew members repair, maintain and upgrade parts of the International Space Station. These activities can also be referred to as EVAs – Extravehicular Activities. Not only do spacewalks require an enormous amount of work to prepare for, but they are physically demanding on the astronauts. They are working in the vacuum of space in only their spacewalking suit.
8. Smart people are up all night working in control rooms all over NASA to ensure that data keeps flowing from our satellites and spacecraft
Our satellites and spacecraft help scientists study Earth and space. Missions looking toward Earth provide information about clouds, oceans, land and ice. They also measure gases in the atmosphere, such as ozone and carbon dioxide and the amount of energy that Earth absorbs and emits. And satellites monitor wildfires, volcanoes and their smoke.
9. A lot of NASA-developed tech has been transferred for use to the public
Our Technology Transfer Program highlights technologies that were originally designed for our mission needs, but have since been introduced to the public market. HERE are a few spinoff technologies that you might not know about.
10. We have a spacecraft currently traveling to an asteroid to collect a sample and bring it back to Earth
OSIRIS-REx is our first-ever mission that will travel to an asteroid and bring a sample of it back to Earth. Currently, the spacecraft is on its way to asteroid Bennu where it will survey and map the object before it “high-fives” the asteroid with its robotic arm to collect a sample, which it will send to Earth.
If everything goes according to plan, on Sept. 24, 2023, the capsule containing the asteroid sample will make a soft landing in the Utah desert.
11. There are Earth-sized planets outside our solar system that may be habitable
To date, we have confirmed 3,000+ exoplanets, which are planets outside our solar system that orbit a Sun-like star. Of these 3,000, some are in the habitable zone – where the temperature is just right for liquid water to exist on the surface.
Recently, our Spitzer Space Telescope revealed the first known system of SEVEN Earth-size planets around a single star. Three of these plants are firmly in the habitable zone, and could have liquid water on the surface, which is key to life as we know it.
12. Earth looks like art from space
In 1960, the United States put its first Earth-observing environmental satellite into orbit around the planet. Over the decades, these satellites have provided invaluable information, and the vantage point of space has provided new perspectives on Earth.
The beauty of Earth is clear, and the artistry ranges from the surreal to the sublime.
13. We’re building a telescope that will be able to see the first stars ever formed in the universe
Wouldn’t it be neat to see a period of the universe’s history that we’ve never seen before? That’s exactly what the James Webb Space Telescope (JWST) will be able to do…plus more!
Specifically, Webb will see the first objects that formed as the universe cooled down after the Big Bang. We don’t know exactly when the universe made the first stars and galaxies – or how for that matter. That is what we are building Webb to help answer.
Happy Friday the 13th! We hope it’s out-of-this-world!
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.
Firefighter Uniform
Japan
c.1900
The MET
Tarde azulada Ossos que anunciam um calor fraco Luz que chega calmamente Um prelúdio com sons que triscam Em contraste ao branco frio.
