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Fish

Physicists develop model of ammonite' coiled spiral shell

ammonite
© Henrich Harder/Wikipedia
Ammonites as they would appear in life
Ammonites are a group of extinct cephalopod mollusks with ribbed spiral shells. They are exceptionally diverse and well known to fossil lovers. Régis Chirat, researcher at the Laboratoire de Géologie de Lyon: Terre, Planètes et Environnement (CNRS/Université Claude Bernard Lyon 1/ENS de Lyon), and two colleagues from the Mathematical Institute at the University of Oxford have developed the first biomechanical model explaining how these shells form and why they are so diverse. Their approach provides new paths for interpreting the evolution of ammonites and nautili, their smooth-shelled distant "cousins" that still populate the Indian and Pacific oceans. This work has just been published on the website of the Journal of Theoretical Biology.

ammonite shell
© Derek Moulton, Alain Goriely and Régis Chirat
The mechanical model predicts the correlations observed between rib frequency and amplitude and the shell's general shape in ammonites (blue morphological space) and nautili (red morphological space) The 3D-views produced by the model are juxtaposed with fossil specimens, ammonites and nautili, that have a similar shape. The ribs tend to disappear for the broadly open shell shapes that have characterized nautili for almost 200 million years. W = expansion rate D = coiling tightness
The shape of living organisms evolves over time. The questions raised by this transformation have led to the emergence of theories of evolution. To understand how biological shapes change over a geological time scale, researchers have recently begun to investigate how they are generated during an individual's development and growth: this is known as morphogenesis. Due to the exceptional diversity of their shell shapes and patterns (particularly the ribs), ammonites have been widely studied from the point of view of evolution but the mechanisms underlying the coiled spirals were unknown until now. Researchers therefore attempted to elucidate the evolution of these shapes without knowing how they had emerged.

Régis Chirat and his team have developed a model that explains the morphogenesis of these shells. By using mathematical equations to describe how the shell is secreted by ammonite and grows, they have demonstrated the existence of mechanical forces specific to developing mollusks. These forces depend on the physical properties of the biological tissues and on the geometry of the shell. They cause mechanical oscillations at the edge of the shell that generate ribs, a sort of ornamental pattern on the spiral.
Solar Flares

The Sun's atmosphere is hotter than its surface, says NASA

Sun
© NASA, Lockheed Martin Solar & Astrophysics Laboratory
NASA’s Solar Dynamics Observatory provided the outer image of a coronal mass ejection on May 9, 2014. The IRIS spacecraft.
NASA's Interface Region Imaging Spectrograph (IRIS) has provided scientists with five new findings into how the sun's atmosphere, or corona, is heated far hotter than its surface, what causes the sun's constant outflow of particles called the solar wind, and what mechanisms accelerate particles that power solar flares.

The new information will help researchers better understand how our nearest star transfers energy through its atmosphere and track the dynamic solar activity that can impact technological infrastructure in space and on Earth. Details of the findings appear in the current edition of Science.

"These findings reveal a region of the sun more complicated than previously thought," said Jeff Newmark, interim director for the Heliophysics Division at NASA Headquarters in Washington. "Combining IRIS data with observations from other Heliophysics missions is enabling breakthroughs in our understanding of the sun and its interactions with the solar system."
Bizarro Earth

Four San Francisco fault lines have built up enough seismic strain to unleash destructive earthquakes

northern california fault lines

San Francisco Bay Area earthquake faults are drawn in red.
With several faults slicing through the San Francisco Bay Area, forecasting the next deadly earthquake becomes a question of when and where, not if.

Now researchers propose that four faults have built up enough seismic strain (stored energy) to unleash destructive earthquakes, according to a study published today (Oct. 13) in the Bulletin of the Seismological Society of America.

The quartet includes the Hayward Fault, the Rodgers Creek Fault, the Green Valley Fault and the Calaveras Fault. While all are smaller pieces of California's San Andreas Fault system, which is more than 800 miles (1,300 kilometers) long, the four faults are a serious threat because they directly underlie cities.
Question

Dinosaurs may have been heavy, wet breathers

© Corbis
Illustration of the Cretaceous pachycephalosaur Stegoceras.
The first ever reconstruction of how dinosaurs breathed finds that these long-extinct animals used each heavy, mucous-moistened breath to smell their surroundings and to cool their brains.

The study, published in the Anatomical Record, helps to explain why most non-avian dinosaurs had such long snouts. It also adds another dimension of life to these prehistoric animals, the last of which took its final breath around 65 million years ago.

Lead author Jason Bourke and his team used plant-eating Stegoceras as a model dinosaur since it had a particularly bony skull with fossilized bones in its nasal region still in place.
Mars

MAVEN spacecraft finds oxygen and hydrogen in Mars' atmosphere

© NASA/Univ. of Colorado
These are two views of Mars' escaping atmospheric gases -- oxygen and hydrogen -- obtained by MAVEN's Imaging Ultraviolet Spectrograph.
Early results from NASA's recently arrived MAVEN Mars spacecraft show an extensive, tenuous cloud of hydrogen surrounding the Red Planet, the result of water breaking down in the atmosphere, scientists said Tuesday.

MAVEN, an acronym for Mars Atmosphere and Volatile Evolution, arrived on Sept. 21 to help answer questions about what caused a planet that was once warm and wet to turn into the cold, dry desert that appears today.
Galaxy

Construction secrets of a galactic metropolis

APEX reveals hidden star formation in protocluster

Protocluster
© ESO/M. Kornmesser
This artist's impression depicts the formation of a galaxy cluster in the early Universe.
Galaxy clusters are the largest objects in the Universe held together by gravity but their formation is not well understood. The Spiderweb Galaxy (formally known as MRC 1138-2621) and its surroundings have been studied for twenty years, using ESO and other telescopes2, and is thought to be one of the best examples of a protocluster in the process of assembly, more than ten billion years ago.

But Helmut Dannerbauer (University of Vienna, Austria) and his team strongly suspected that the story was far from complete. They wanted to probe the dark side of star formation and find out how much of the star formation taking place in the Spiderweb Galaxy cluster was hidden from view behind dust.

The team used the LABOCA camera on the APEX telescope in Chile to make 40 hours of observations of the Spiderweb Cluster at millimeter wavelengths - wavelengths of light that are long enough to peer right through most of the thick dust clouds. LABOCA has a wide field and is the perfect instrument for this survey.

Carlos De Breuck (APEX project scientist at ESO, and a co-author of the new study) emphasizes: "This is one of the deepest observations ever made with APEX and pushes the technology to its limits - as well as the endurance of the staff working at the high-altitude APEX site, 5050 meters above sea level."
Blue Planet

Could Earth's magnetic field flip within a human lifetime?

Biaggio Giaccio
© Paul Renne
Left to right, Biaggio Giaccio, Gianluca Sotilli, Courtney Sprain and Sebastien Nomade sitting next to an outcrop in the Sulmona basin of the Apennine Mountains that contains the Matuyama-Brunhes magnetic reversal. A layer of volcanic ash interbedded with the lake sediments can be seen above their heads. Sotilli and Sprain are pointing to the sediment layer in which the magnetic reversal occurred.
Imagine the world waking up one morning to discover that all compasses pointed south instead of north.

It's not as bizarre as it sounds. Earth's magnetic field has flipped - though not overnight - many times throughout the planet's history. Its dipole magnetic field, like that of a bar magnet, remains about the same intensity for thousands to millions of years, but for incompletely known reasons it occasionally weakens and, presumably over a few thousand years, reverses direction.

Now, a new study by a team of scientists from Italy, France, Columbia University and the University of California, Berkeley, demonstrates that the last magnetic reversal 786,000 years ago actually happened very quickly, in less than 100 years - roughly a human lifetime.

"It's amazing how rapidly we see that reversal," said UC Berkeley graduate student Courtney Sprain. "The paleomagnetic data are very well done. This is one of the best records we have so far of what happens during a reversal and how quickly these reversals can happen."

Sprain and Paul Renne, director of the Berkeley Geochronology Center and a UC Berkeley professor-in- residence of earth and planetary science, are coauthors of the study, which will be published in the November issue of Geophysical Journal International and is now available online.
Beaker

Siberia to continue to hold Russia's only stock of smallpox

© The Siberian Times
Vector is currently engaged in research into the critical worldwide threat from Ebola.
Strains of the deadly disease remain at the high security Vector Research Centre.

Only two stocks of eradicated smallpox remain in the world, in Koltsovo, near Novosibirsk, and in the American city of Atlanta.

The head of Vector, the Russian State Research Centre of Virology and Biotechnology, said today that there are no immediate plans to destroy the virus stocks.

'The collection remains as it was. No one is planning to destroy it', said Valery Mikheyev, as cited by RIA Novosti.

A final decision on the fate of the stocks is to be made by the World Health Organisation, which declared smallpox eradicated in 1980.
Network

Passwords of 7M Dropbox accounts seized

dropbox hacked
The passwords of nearly 7 million Dropbox accounts have been seized through third-party services and 400 directly leaked on Pastebin, with promises of more leaks following bitcoin donations. Dropbox denies a hack.

The leaker described the 400 as a "first teaser...just to get things going" and followed with: "More Bitcoin = more accounts published on Pastebin. As more BTC is donated, More pastebin pastes will appear."

It remains unclear how the details were obtained; the hackers claim ownership of details from 6,937,081 different accounts - claims that cannot in any way be verified.

Dropbox, denies that a hack has taken place.

"Dropbox has not been hacked. These usernames and passwords were unfortunately stolen from other services and used in attempts to log in to Dropbox accounts," it said.

"We'd previously detected these attacks and the vast majority of the passwords posted have been expired for some time now. All other remaining passwords have expired as well."

Comment: Rather interesting in light of Snowden's recent comments saying that Dropbox and other such services are "hostile to privacy". He urged web users to abandon unencrypted communication and adjust privacy settings to prevent governments from spying on them in increasingly intrusive ways.

Snowden says, 'Get rid of DropBox' and avoid Facebook

Red Flag

Friends of the Earth petitions NRC to consider new alarming seismic data regarding Diablo Canyon relicensing

Diablo Canyon
© archive.fortune.com
Diablo Canyon Nuclear Power Plant
Request Follows Dramatic Findings That Nuclear Reactors are Surrounded by Stronger and Inter-connected Earthquake Faults

Friends of the Earth has filed a petition to intervene in the Nuclear Regulatory Commission proceeding that would allow Pacific Gas & Electric's controversial Diablo Canyon nuclear reactors to run for an additional twenty years.

The new seismic data released in September by the utility reveals that the 1960s-era Diablo Canyon reactors are surrounded by larger, interconnected faults capable of producing earthquakes that far exceed the plant's licensed design. Friends of the Earth argues that the plant's ability to withstand such earthquakes should be considered in a public hearing on the seismic safety of the PG&E reactors before the license extension to operate Diablo Canyon into the mid-2040s can be decided.

"This new, alarming seismic data clearly shows that faults surrounding Diablo Canyon could produce earthquakes far more powerful than those for which the plant is designed - this is a recipe for disaster," said Damon Moglen of Friends of the Earth "It's now clear that Diablo Canyon could never get a license to be built at its current Central Coast site. The NRC must consider this seismic data as part of public licensing hearings."

Comment: Decrepit reactors (designed in the 1960s and built in the 1970s) on an array of active seismic faults in close proximity, what are the odds on nothing happening (especially in lieu of the Pac-Rim uptick of late)? Recent 3-D studies detecting three new faults, provide unprecedented scientific analysis of the seismic characteristics near Diablo Canyon. Faults include: Hosgri, San Simeon, Shoreline, Los Osos and San Luis Bay faults. Nearby is the dreaded San Andreas Fault - only 45 miles inland, and the Rinconada - 20 miles inland.

It has become increasingly clear that Diablo Canyon is surrounded by faults capable of creating ground motion beyond that for which the reactors and their components were tested and licensed. The Hosgri Fault, about 3 miles offshore, is capable of producing a major earthquake of magnitude 7.5. Upgraded information and studies on the faults near Diablo Canyon have revealed the percentages of more ground vibration and surface shaking that will occur during an earthquake: The Los Osos Fault - 50% more, San Luis Fault - 75% more, Shoreline Fault - 55% more. It has taken six years for PG&E to acknowledge the risks of the Shoreline Fault, first identified in 2008. While short segments can work together to produce stronger earthquakes as in the Fukushima disaster, there are factors that suggest the Shoreline Fault is one continuous segment, amplifying its potential by several magnitudes.

Hundreds of thousands of Californians live in the wake of this potential disaster, with approximately 500,000 persons living within a 50 mile radius of the plant. The persistent drought, now being experience in California, is potentially capable of setting off more earthquakes. Diablo Canyon is rated number one in the magnitude of potential (and preventable) devastation in the USA.

Here is a quick PBS special (run time 15 minutes) - informative and non-biased, illustrating the NRC and PG&E's long history of deceit about safety of Diablo Canyon: http://video.pbs.org/video/205

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