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[LINK] “Sea level has climbed 8 centimetres since 1992”

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CBC carries the Thomson Reuters report noting that sea levels have already risen in the past two decades.

Sea levels worldwide rose an average of nearly eight centimetres (3 inches) since 1992, the result of warming waters and melting ice, a panel of NASA scientists said on Wednesday.

In 2013, a United Nations panel predicted sea levels would rise from 0.3 to 0.9 metres (1 to 3 feet) by the end of the century.

The new research shows that sea level rise most likely will be at the high end of that range, said University of Colorado geophysicist Steve Nerem.

Sea levels are rising faster than they did 50 years ago and “it’s very likely to get worse in the future,” Nerem said.

The changes are not uniform. Some areas showed sea levels rising more than 25 cm (9 inches) and other regions, such as along the U.S. West Coast, actually falling, according to an analysis of 23 years of satellite data.

Written by Randy McDonald

August 27, 2015 at 7:48 pm

[LINK] “More Evidence That Comets May Have Brought Life to Earth”

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Universe Today’s Nancy Atkinson presents evidence comets may have contributed to life on Earth, not by importing it but rather by making the precursor chemical compounds to life.

The idea of panspermia — that life on Earth originated from comets or asteroids bombarding our planet — is not new. But new research may have given the theory a boost. Scientists from Japan say their experiments show that early comet impacts could have caused amino acids to change into peptides, becoming the first building blocks of life. Not only would this help explain the genesis of life on Earth, but it could also have implications for life on other worlds.

Dr. Haruna Sugahara, from the Japan Agency for Marine-Earth Science and Technology in Yokahama, and Dr. Koichi Mimura, from Nagoya University said they conducted “shock experiments on frozen mixtures of amino acid, water ice and silicate (forsterite) at cryogenic condition (77 K),” according to their paper. “In the experiments, the frozen amino acid mixture was sealed into a capsule … a vertical propellant gun was used to [simulate] impact shock.”

They analyzed the post-impact mixture with gas chromatography, and found that some of the amino acids had joined into short peptides of up to 3 units long (tripeptides).

Based on the experimental data, the researchers were able to estimate that the amount of peptides produced would be around the same as had been thought to be produced by normal terrestrial processes (such as lighting storms or hydration and dehydration cycles).

Written by Randy McDonald

August 19, 2015 at 9:38 pm

Posted in Science

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[BLOG] Some Friday links

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  • blogTO lists the ten weirdest houses in Toronto.
  • Centauri Dreams takes issue with the science of Kim Stanley Robinson’s new novel Aurora.
  • Crooked Timber notes the ongoing controversy regarding the dismissal of Steven Salaita.
  • The Dragon’s Gaze reports on the imaging of exoplanet 51 Eridani b.
  • Joe. My. God. notes that Madonna is abandoning Russia for its homophobia.
  • The Power and the Money notes Douglas Muir’s argument that dictatorship, as a system of government, has not become less common.

[LINK] On the genetics of the octopus

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I liked to the sensationally-titled Metro.co.uk article “Octopuses ‘are aliens’, scientists decide after DNA study” because it was so sensational. A Facebook friend’s suggestion, by way of providing inspiration of science fiction writers, that contemporary cephalopods are actually the technology-less descendants of ancient alien visitors, amused me. Another friend linked to Janet Fang’s IFL Science article “The California Two-Spot Is The First Octopus To Have Its Genome Sequenced”, much more sober and informative.

Cephalopods, which include the octopus, squid, cuttlefish, and nautilus, emerged as predators throughout the ancient seas half a billion years ago. They were likely the first intelligent life-forms on Earth, and these days, the list of octopus innovations is long and impressive: camera-like eyes, the ability to regenerate complex limbs, a propulsion system, and three hearts that keep blood pumping across the gills, to name a few.

Now, to investigate the molecular basis of the cephalopod brain – the largest nervous system among invertebrates – as well as their cool innovations, a team led by University of Chicago’s Caroline Albertin isolated and sequenced genomic DNA from a single male California two-spot octopus, Octopus bimaculoides. These clever problem solvers have a blue eyespot on either side of their heads. A juvenile female is pictured below to the right.

The octopus genome is about 2.7 billion base pairs in size, with long stretches of repeated sequences and more than 33,000 protein-coding genes. This means that their genome is slightly smaller than ours, but they have more genes. Researchers used to think that the large size of the octopus genome was due to whole genome duplication events during their evolution. But while these can result in increased genomic complexity, the team found no evidence of duplications.

Rather, a couple of gene families expanded, novel genes appeared, and the whole genome was shuffled around. “With a few notable exceptions, the octopus basically has a normal invertebrate genome that’s just been completely rearranged, like it’s been put into a blender and mixed,” Albertin says in a statement. “This leads to genes being placed in new genomic environments with different regulatory elements.”

Nature‘s “Octopus genome holds clues to uncanny intelligence” goes into more detail.

[T]he octopus genome turned out to be almost as large as a human’s and to contain a greater number of protein-coding genes — some 33,000, compared with fewer than 25,000 in Homo sapiens.

This excess results mostly from the expansion of a few specific gene families, Ragsdale says. One of the most remarkable gene groups is the protocadherins, which regulate the development of neurons and the short-range interactions between them. The octopus has 168 of these genes — more than twice as many as mammals. This resonates with the creature’s unusually large brain and the organ’s even-stranger anatomy. Of the octopus’s half a billion neurons — six times the number in a mouse — two-thirds spill out from its head through its arms, without the involvement of long-range fibres such as those in vertebrate spinal cords. The independent computing power of the arms, which can execute cognitive tasks even when dismembered, have made octopuses an object of study for neurobiologists such as Hochner and for roboticists who are collaborating on the development of soft, flexible robots.

A gene family that is involved in development, the zinc-finger transcription factors, is also highly expanded in octopuses. At around 1,800 genes, it is the second-largest gene family to be discovered in an animal, after the elephant’s 2,000 olfactory-receptor genes.

The analysis also turned up hundreds of other genes that are specific to the octopus and highly expressed in particular tissues. The suckers, for example, express a curious set of genes that are similar to those that encode receptors for the neurotransmitter acetylcholine. The genes seem to enable the octopus’s remarkable ability to taste with its suckers.

Written by Randy McDonald

August 14, 2015 at 7:33 pm

[LINK] “Newfoundland fossil may show earliest reproduction in complex organism”

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The CBC reports on the discovery in Newfoundland of fossils a half-billion years old providing hints about how reproduction first occurred among complex organisms.

A team led by researchers from England’s University of Cambridge found the fossils in the Trinity Bay North area. The new fossils were estimated to be 565 million years old and belonged to Fractofusus, a type of rangeomorph. Rangemorphs, marine organisms that looked a bit like ferns, were some of the earliest complex organisms on Earth. Earlier life forms were mostly single-celled and reproduced simply by dividing.

The Fractofusus fossils are clustered together in a way that suggests there are three generations of organisms in a cluster — larger, older ones surrounded by younger, smaller ones.

Jack Matthews of Oxford University has been studying rocks in Newfoundland for about eight years. He was part of the team that found the fossils.

“It [the clustering] suggests that these organisms could reproduce rapidly via what’s known as asexual reproduction,” said Matthews.

The pattern strongly resembles clustering observed in modern plants such as strawberries, where smaller offspring grow from “runners” sent out by the older generation.

Written by Randy McDonald

August 4, 2015 at 12:16 am

[CAT] “Cecil Is One of Hundreds of Lions Killed Recently in Zimbabwe”

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National Geographic‘s Brian Clark Howard reports about the science involved in the hunting of lions in Zimbabwe.

Zimbabwe is thought to have between 500 and 1,680 lions remaining, about 80 percent of which live in protected areas. The country has the highest proportion of lions that can be legally hunted, along with Tanzania, which is home to 40 percent of Africa’s lions.

Across the continent, lion numbers have plummeted by more than 80 percent over the past century, from 200,000 to less than 30,000.

Zimbabwe’s poverty and remoteness has made it harder for game officials there to keep a close eye on legal lion hunting and to prevent poaching than in some surrounding countries, says Wayne Bisbee, a trophy hunter and conservationist who often visits Africa. Zimbabwe is also often cited for its corruption—its president, Robert Mugabe, has ruled the country for 35 years— which can lead to lax or unequal enforcement.

[. . .]

In 2013, 49 legal lion trophies were exported from Zimbabwe, out of about 665 such trophies that come from Africa each year.

Zimbabwe’s wildlife authority has issued a statement saying it is aggressively investigating what it calls the illegal hunt of Cecil and has jailed two of the guides that arranged the shooting trip of American dentist Walter Palmer. The guides currently on bail in the Cecil case could face as much as 15 years in prison, and Zimbabwe’s authorities have asked for Palmer to be extradited to their country to face possible charges.

Written by Randy McDonald

August 1, 2015 at 10:43 pm

Posted in Science

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[BLOG] Some Wednesday links

  • blogTO notes that ferry tickets for the Toronto Islands can now be bought online.
  • Discover‘s Crux considers SETI.
  • The Dragon’s Gaze links to a paper considering habitable exoplanets around nearby red dwarf stars, defends the potential existence of exoplanets at Kapteyn’s Star, and looks at the Epsilon Eridani system.
  • The Dragon’s Tales notes that a second Scottish referendum on independence is possible, according to Alex Salmond.
  • Joe. My. God. notes that Mormons are unhappy with the Scouts’ gay-friendly shift.
  • Language Hat considers the history of family name usage in Russia.
  • Languages of the World examines in two posts the argument that primitive peoples have simple languages.
  • Lawyers, Guns and Money considers the strategies of Spanish populist group Podemos.
  • Peter Watts considers the peculiar thing of people lacking large chunks of the brain who nonetheless seem normal.
  • Diane Duane, at Out of Ambit, is quite unhappy with an impending forced upgrade to Windows 10.
  • Personal Reflections’ Jim Belshaw notes how labour-saving technologies improved the lives of women.
  • The Planetary Society Blog considers proposals to explore small solar system bodies.
  • The Power and the Money’s Noel Maurer considers what would happen if Bernie Sanders won the nomination of the Democratic Party.
  • The Russian Demographics Blog links to statistics on the population of Abu Dhabi.
  • Window on Eurasia notes the depopulation of South Ossetia and looks at the Russian Orthodox Church’s hostility to Ukraine’s Uniate Catholics.
  • Yorkshire Ranter Alex Harrowell notes that although Labour apparently did a good job of convincing potential voters it was right, it did a worse job of getting them to vote.

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