21 August 2017
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Today’s eclipse was the first total solar eclipse visible from most of the continental United States since 1979. Millions of people travelled to experience the celestial event along the 70-mile-wide path of totality that spanned the width of the country from Oregon to South Carolina.
This high resolution imagery of the Moon’s shadow passing over the United States was captured by the GOES-16 satellite. It is the first of the next generation of geosynchronous environmental satellites jointly operated by NASA and NOAA that will provide atmospheric and surface measurements of Earth. Data from the GOES system is used for weather forecasting, severe storm tracking, space weather monitoring, and meteorological research.
Source: https://goo.gl/6yYYKB (NOAA)
#ScienceGIF #Science #GIF #Solar #Eclipse #Totality #NOAA #NASA #Satellite #Space #GOES16 #Geosynchronous #Environment #Climate #Weather #Meteorology #Geocolor #Animation #Clouds #Shadow #Penumbra #Umbra #United #States #America #USA
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19 August 2017
On Monday, August 21st, the continental United States will experience its first total solar eclipse since 1979 as the Moon passes in front of the Sun. During the period of time when the Moon completely obscures the Sun (totality), the solar corona will become visible to the naked eye. This aura of plasma surrounds all stars and extends millions of kilometers into space. The corona is also much hotter than the visible surface of the Sun, with temperatures ranging between 1,000,000 - 3,000,000° Celsius.
This timelapse depicts a total solar eclipse that occurred in November 2012 as seen from Queensland, Australia. Ángel R. López-Sánchez at the Australian Astronomical Observatory captured this imagery using a refractor telescope with a solar filter blocking 99.9997% of the incident light.
Source: https://goo.gl/bNyBE6 (Ángel R. López-Sánchez)
Learn More: https://eclipse2017.nasa.gov/ (+NASA)
#ScienceGIF #Science #GIF #Eclipse #Solar #Sun #Moon #Orbit #Umbra #Penumbra #Astronomy #Timelapse #Observatory #Telescope #Skywatcher #Canon #Totality #Obscuration
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12 August 2017
Hummingbirds are small birds that live exclusively in the Americas and are famous for their rapid motion and high-frequency wing beating. They have the highest metabolism of any animal that maintains a stable internal body temperature (homeothermic) with heart rates of well over 1,000 beats-per-minute. During flight, oxygen consumption per gram of muscle tissue in a hummingbird is about 10x higher than that measured in elite human athletes. In order to sustain such a high level of activity, hummingbirds must constantly consume sugar from flower nectar.
Hummingbirds drink with their tongues using a rapid lapping motion. Contrary to prior belief, capillary action plays no role in propelling nectar up the groves of the tongue. Scientists using high-speed cameras discovered that the tongue remains compressed until it reaches the nectar, at which point it springs open, forcing the liquid up the grooves of the tongue in a pump-like manner.
Source: https://youtu.be/RtUQ_pz5wlo (+National Geographic)
Learn More: https://nyti.ms/2kXRq7z (+The New York Times)
#ScienceGIF #Science #GIF #Hummingbird #Bird #Nature #SlowMotion #SlowMo #Slow #Motion #High #Speed #Tongue #Drink #Capillary
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5 August 2017
When a high voltage is applied across two beakers filled with deionized water a phenomenon known as an electrohydrodynamic bridge can occur. The unsupported strand of water appears to defy gravity as the beakers are slowly separated. First demonstrated in 1893 by Sir William Armstrong, the floating water bridge has yet to be fully explained despite involving a number of important water science concepts.
The polar molecule water (H2O) has a permanent dipole moment and therefore acts as a dielectric fluid because it can be polarized in the presence of an applied electric field. The macroscopic behavior of the polarized fluid is governed by electrohydrodynamics, which describes several phenomena that occur as the magnitude of the electric field increases. These include an increase in meniscus height (electrowetting), bulk fluid circulation (Sumoto effect), and the ejection of charged droplets (electrospray). The electric field also exerts a force known as dielectrophoresis on the water molecules, which causes water to flow across the bridge and is likely involved in holding the stream together.
While this particular demonstration was performed using deionized water, any polar dielectric fluid could be used instead (e.g. glycerol or DMSO).
Source: https://youtu.be/2RSr2pHJJ98
Learn More: https://doi.org/10.3791/51819 (JoVE)
#ScienceGIF #Science #GIF #Water #Voltage #Beaker #Bridge #Floating #Electrohydrodynamic #Electric #Hydrodynamic #Physics #Molecules #Polarity #Electricity
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29 July 2017
Compared to a baseline period beginning in the 1950’s, summers in the northern hemisphere are becoming increasingly hotter. This data depicts the shifting distribution of June, July, and August land temperature anomalies (departure from long-term average) over subsequent decades.
The normal distribution of the 1951 to 1980 baseline data was used to define three temperature categories (cold, normal, and hot), so that a third of the data fell into each bin. Since then, summer temperatures have shifted drastically such that between 2005 to 2015, two-thirds of all values were in the “hot” category. In fact, the distribution shifted so far that a new category “extremely hot” had to be added since almost 15% of the data exceeded the original scale.
The broadening of the distribution is also of interest since it seems to imply that there is greater temperature variability now than in the past. However, climate scientists suspect this is actually caused by parts of the world warming faster than others. When the effects of regional variability in global warming are taken into account, the increased variability in temperature anomalies is significantly reduced.
Source: https://nyti.ms/2u4xwrY
Publications: https://goo.gl/SnucV2, https://goo.gl/Jaj7f8
Data: https://goo.gl/zP8Rpk (Columbia University)
#ScienceGIF #Science #GIF #ClimateChange #Climate #Change #GlobalWarming #Global #Warming #Climatology #Temperature #Anomaly #Distribution #Hemisphere #BellCurve #Gaussian #NASA #Columbia #University #NYT #NYTimes
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22 July 2017
Vaccines are one of humanity’s greatest inventions and historically the most effective means to fight and eradicate infectious diseases. As long as the vast majority of a population is vaccinated against a disease, it becomes very difficult for an outbreak to occur. This concept is called herd immunity and allows for the unvaccinated, such as infants or those with compromised immune systems, to remain protected from the disease.
This GIF visualizes how vaccination rates influence herd immunity within a given population. As the proportion of vaccinated individuals increases, the transmission of disease is reduced. Once a critical proportion of the population becomes immune, the disease can no longer sustain itself and ceases to be endemic. At this point, those who are unable to receive vaccinations become protected from the disease because of the immunity of the rest of the community.
The proportion of the population that needs to be vaccinated is called the herd immunity threshold and is estimated using epidemiological models. Highly infectious diseases such as measles require 92-95% of the population to be vaccinated. Less infectious diseases such as influenza only require population immunity of 33-44%.
Vaccines do more than just protect you and your children from terrible diseases. They help protect everyone around you.
Source: https://redd.it/5v72fw (/u/theotheredmund)
Learn More: https://goo.gl/D3EwJA (PBS Nova)
#ScienceGIF #Science #GIF #Immune #System #Immunity #Herd #Vaccine #Immunization #Epidemiology #Disease #Study #Medicine #Model #Transmission #Infection #Virus
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15 July 2017
Scientists at Harvard Medical School have used the CRISPR/Cas system to encode an animated GIF into the DNA of living E. coli bacteria. They used Eadweard Muybridge ‘s famous 1872 footage of a galloping horse as the source material. In order to prepare the short film for genome insertion, each digital frame was encoded into a nucleic acid sequence. Because DNA has four nucleotides, the digital data was converted from binary (base-2) into quaternary (base-4).
CRISPR/Cas is part of the prokaryotic immune system that helps confer resistance to foreign genetic elements and provides a form of acquired immunity. When exposed to exogenous genetic material, Cas proteins will permanently incorporate it into the bacterial genome for future reference. By exploiting this system, scientists have figured out how to easily insert data into and modify genomes (CRISPR/Cas9).
The DNA containing the encoded frames were manufactured and transported into E. coli bacteria where the CRISPR system grabbed the genetic material and inserted it into its own genome. The bacteria was allowed to replicate overnight and then sampled for genetic sequencing. By examining the part of the genome where CRISPR information is stored, the scientists were able to extract and decode the image sequence back into binary digital data. The reconstructed animation can be seen below.
Source: https://goo.gl/PCxHrB (The Verge)
Paper: https://dx.doi.org/10.1038/nature23017 (Nature)
#ScienceGIF #Science #GIF #Genome #CRISPR #Cas9 #Movie #Digital #Genetic #Data #Biology #Microbes #Bacteria #EColi #Horse #Muybridge #GeorgeChurch #DNA #Nucleotide #RNA #Binary #Quaternary
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8 July 2017
Magnetic resonance imaging (MRI) has revolutionized medicine and biomedical research since its inception in the early 1970’s. The technique relies upon strong magnetic fields and radio waves to non-invasively generate three-dimensional anatomical imagery without requiring the use of ionizing radiation (e.g. x-rays).
This detailed scan of the brain generated by Cardiff University’s Brain Research Imaging Centre uses a different MRI technique called Diffusion Tensor Imaging (DTI), which maps the flow of water inside the brain. DTI measures a parameter called anisotropy , which describes the directionality of water molecule diffusion within neuronal structures. By performing a voxel-by-voxel analysis, researchers can construct three-dimensional representations of the axonal tracts in the brain.
Source: http://www.bbc.com/news/health-40488545 (BBC)
#ScienceGIF #Science #GIF #Brain #Wiring #MRI #DTI #Magnetic #Resonance #Imaging #Medical #Biomedical #Technology #BBC #Axon #Neuron #Tract #Tractography #Flow #Cardiff #University #Research #Scientist #Diffusion #Tensor
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1 July 2017
The intermediate axis theorem , also known as the tennis racket theorem, is a classical mechanics description of the motion of a rigid body with three distinct principal moments of inertia. This means it requires a different amount of torque (rotational force) to rotate the object about each axis. The phenomenon is also known as the Dzhanibekov effect after the Russian cosmonaut Vladimir Dzhanibekov who demonstrated the theorem in 1985 while in space.
The theorem states that rotation of an object around its first and third principal axes is stable whereas rotation around its second principal axis (the intermediate axis) is not. When demonstrated in microgravity aboard the International Space Station, the t-shaped handle can be seen flipping back and forth as it spins unstably about its intermediate axis. The theorem can be quantitatively analyzed using Euler’s equations that describe rigid body dynamics.
Source: https://youtu.be/1n-HMSCDYtM
KSP Explanation: https://youtu.be/-Si6iRL5Fj8
#ScienceGIF #Science #GIF #NASA #Astronaut #Physics #Dzhanibekov #Spin #Procession #Inertia #Torque #Tennis #Racket #Theorem #Intermediate #Axis #Microgravity #Gravity #Space #ISS #Euler
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24 June 2017
For the first time, scientists at the University of California, Davis have imaged the replication of a single DNA molecule. Replication of genetic material occurs in all known living organisms and is the basis of biological inheritance.
Deoxyribonucleic acid (DNA) is made up of two complementary strands of nucleotides acids famously structured as a double helix. Prior to replication, an enzyme called helicase unwinds the DNA double helix into two separate strands (ssDNA). DNA polymerase enzymes then bind to each ssDNA and begin replicating the complement to form two copies of the genetic material.
In order to visualize the replication of individual DNA molecules, scientists used a circular piece of DNA attached to a glass slide in a flow chamber. As the replication enzymes proceed around the circle, the resulting copy gets longer and longer. By adding a fluorescent dye that only binds to double-stranded DNA, it becomes possible to visualize the growing molecule using a high-resolution optical microscope.
Source: https://goo.gl/7RLDjK (UC Davis)
#ScienceGIF #Science #GIF #DNA #Replication #Biology #Microscopy #Fluorescence #Strand #DoubleHelix #Helix #Enzyme #Helicase #Primase #Polymerase #DeoxyribonucleicAcid #NucleicAcid #Nucleic
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