понедельник, 26 ноября 2018 г.

Bone Tools, Jewellery, Buttons and Ornamentation, Devizes Museum, Wiltshire, 17.11.18.

Bone Tools, Jewellery, Buttons and Ornamentation, Devizes Museum, Wiltshire, 17.11.18.

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Prehistoric Stone Handtools and Worked Stone, Devizes Museum, Wiltshire, 17.11.18.

Prehistoric Stone Handtools and Worked Stone, Devizes Museum, Wiltshire, 17.11.18.

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Misshapen Minds Mess tends to build up slowly, gradually…

Misshapen Minds

Mess tends to build up slowly, gradually gathering until you’re suddenly overrun with clutter and can’t find anything you need. A similar accumulation of unwanted debris can happen in the brain, resulting in conditions like Alzheimer’s and Parkinson’s. Misshapen proteins clump to form plaques that clog up the brain. Understanding and predicting how this clutter gathers might help spot and stave off illnesses, so researchers have developed a new simulation of the process. They examined the formations in recently deceased patients’ brains, and then modelled how they would have taken shape. Although the diseases are incredibly complex, this progression is surprisingly consistent. Their simulations, such as the Alzheimer’s development pictured with the memory-wrecking protein amyloid beta in orange, and destructive tau protein in blue, illustrate formations that can develop over 30 years. Better understanding of how small clumps spread to engulf the brain might help earlier diagnosis, and eventually better treatments.

Written by Anthony Lewis

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Hey Sucker! Image of the Week – November 26, 2018CIL:41648 -…

Hey Sucker! Image of the Week – November 26, 2018


Description: Hymenolepis microstoma, a tapeworm parasite, showing anterior end. Phalloidin staining shows the suckers, pharynx and part of the body-wall musculature. Confocal microscopy. Honorable Mention, 2011 Olympus BioScapes Digital Imaging Competition®.

Authors: Andreas Schmidt-Rhaesa and 2010 Olympus BioScapes Digital Imaging Competition®

Licensing: Attribution Non-Commercial No Derivatives: This image is licensed under a Creative Commons Attribution, Non-Commercial, No Derivatives License

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Outburst of the Andromedids in 2018?

Andromedids Radiant position at 20:00 (8:00pm) local standard time on December 5, 2018 as seen from latitude 40N (looking EST)

During the period of December 3-5 2011, the Canadian Meteor Orbit Radar installation observed strong activity from a source on the Andromeda/Cassiopeia border. After a lengthy analysis it was determined that these meteors were produced by Comet 3D/Biela during its passage though the inner solar system in 1649. This is the same comet that produced the magnificent Andromedid displays of 1872 and 1885.

Andromedids as seen on the night of November 27, 1872 by Amédée Guillemin (Le Ciel, notions d’astronomie, à l’usage des gens du monde et de la jeunesse, 1864 and 1877)

This sudden appearance of these meteors in 2011 was a surprise and astronomers ran simulations to match past displays and to see if any repeat encounters are in the offing. Calculations indicated that the Earth will again skim the debris field of the 1649 return on or near December 6, 2018. This display is not expected to be as strong as the 2011, which had an estimated zenith hourly rate of 50. Yet any sightings of these extremely slow meteors would be a treat and a link to past history. The expected radiant on the night of December 5/6 would be located near 01:36 (24 degrees) +50, which is located in extreme northern Andromeda, 2 degrees northwest of the 4th magnitude star known as Nembus (aka 51 Andromedae). This area of the sky is situated far enough away from the Taurid radiants that identification should be easy. This area of the sky is well placed high in the northeastern sky as soon as it becomes dark in late November and early December.  Luckily, the moon will be in the morning sky nearly all of this period allowing an unhindered view of possible activity.

It is imperative that potential observers seek the darkest skies possible as most of this activity is expected to be faint. Radar installations such as the one in Canada can pick up meteors fainter than the eye can detect. Yet video cameras have been successful in capturing these meteors so this is encouraging for visual observers. Don’t stare directly at the radiant as shower members occurring there may be too short to see. Place the radiant area at one side of your field of view so that potential shower members can be easily trace back to the radiant.

These meteors have been recently listed in the International Astronomical Union as the December phi Cassiopeiids (DPC) #446 with an activity period of November 28 to December 10. I would make it a point to view for these meteors during this entire period, but especially near December 6th.  Negative reports are just as valuable as positive ones!

A little history reveals this was the main radiant of the Andromedids before the breakup of Comet 3D/Biela in the 1840’s. Subsequent displays including the great Andromedid storms in 1872 and 1885 were produced from a more southerly radiant near the Andromeda/Triangulum border. This radiant is still active today producing low rates between October 26 and November 17 each year.

Lastly, it has been calculated that the return on December 2, 2023 may be 4x as strong as the 2011 display with a possible ZHR near 200! Stay tuned…

This is a view of the northern sky and the position of the radiant at 20:00 (8:00pm) local standard time on December 5, 2018 as seen from latitude 40N.

Information in the article was obtained from “The Return of the Andromedids Meteor Shower” by Paul A. Wiegert, Peter G. Brown, Robert J. Weryk, and Daniel K. Wong. The Astronomical Journal, Volume 145, Number 3. Published 2013 February 8

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Steppe ancestry in Chalcolithic Transcaucasia (aka Armenia_ChL explained)

In 2016 Lazaridis et al. published a paper featuring five ancient samples from the famous Areni-1 cave complex, in what is now Armenia, dated to the Chalcolithic (see here). This is how they described the ancestry of these ancients, which they labeled Armenia_ChL, in the supplementary PDF to their paper (page 94):

We do not have a pre-Chalcolithic sample from Armenia. We first model it [Armenia_ChL] as a 2-way mixture of any of WHG, EHG, CHG, Iran_N, Levant_N, Anatolia_N (Table S7.18), but we find no pair of these populations that could be ancestral to Armenia_ChL. We next model it as a 3-way mixture (Table S7.19), and determine that Armenia_ChL can be modeled as 18.3±1.5 EHG, 29.2±2.4% Iran_N, and 52.5±2.2% Anatolia_N. In the absence of a pre-Chalcolithic sample, we cannot be certain whether the Neolithic population of Armenia (which borders Anatolia from the east) was similar to that of Northwestern Anatolia and experienced gene flow from the east and north, or the reverse.

Since then, a lot of opinions have been posted in the comments at this blog and elsewhere about the possible origin and significance of Armenia_ChL. It seems to me that many people see Armenia_ChL as more or less an example of the indigenous Neolithic and Chalcolithic peoples of the South Caucasus. But some have argued that Armenia_ChL was in large part of Central Asian origin and concocted various mixture models to try and back up this rather strange claim.
To me, it was always obvious that Armenia_ChL harbored very recent admixture from the Pontic-Caspian steppe, because I couldn’t reconcile its relatively high level of Eastern European Hunter-Gatherer (EHG) ancestry with a deep origin south of the Greater Caucasus range.
Moreover, in any decent Principal Component Analysis (PCA), like the one below, Armenia_ChL appears to form two subtle sub-clusters, with three of its individuals “pulling” more strongly towards Eastern Europe. This suggests that the EHG admixture in Armenia_ChL was present at variable levels and thus likely to be recent, because it didn’t yet have time to diffuse evenly throughout the population.
Also, two out of the three Armenia_ChL individuals who are “pulling” north belong to steppe-specific mitochondrial (mtDNA) haplogroups. Armenia_ChL I1634 belongs to mtDNA haplogroup H2a1, which is seen in ancient samples from the Pontic-Caspian steppe associated with the Khvalynsk, Sredny Stog and Catacomb cultures, while Armenia_ChL I1409 belongs to mtDNA haplogroup U4a, which is found in numerous ancient samples, especially foragers, from the Pontic-Caspian steppe and other parts of Eastern Europe (see here). Coincidence? Surely not.

The idea that Armenia_ChL represents a long-standing indigenous Transcaucasian population also took a major hit recently with the release of the Wang et al. manuscript on the genetic prehistory of the Greater Caucasus. The preprint included samples from the Eneolithic Caucasus dated to earlier than Armenia_ChL (4594-4404 calBCE vs 4330-3985 calBCE) which looked typically Caucasian and lacked any discernible signals of ancestry from the steppe. Below is a PCA from Wang et al. featuring both the Eneolithic Caucasus and Armenia_ChL samples.

Unfortunately, modeling the recent ancestry of Armenia_ChL is still difficult, because the genotype data from Wang et al. haven’t yet been released, so currently there is still no pre-Armenia_ChL sample available from the Caucasus for me to work with.
The earliest post-Armenia_ChL sample is Armenia_EBA I1658, dated to around a thousand years too late (3347-3092 calBCE). However, this individual is associated with the Kura-Araxes culture, which is generally seen as a direct successor to the native Neolithic cultures of Transcaucasia, and appears to be practically indistinguishable from the Eneolithic Caucasus trio in the Wang et al. PCA. Thus, pending the release of a pre-Armenia_ChL sample I might be able to use Armenia_EBA I1658 as an effective proxy for such a population.
Below are a couple of successful two-way qpAdm mixture models for Armenia_ChL and Armenia_ChL I1634, featuring Armenia_EBA I1658 and Sredny_Stog I6561 (the output for Armenia_ChL I1409 looked wobbly, probably due to a lack of markers). The reason I decided on Sredny_Stog from the North Pontic steppe as the surrogate for the steppe ancestry is because of the position of Armenia_ChL in the Wang et al. PCA relative to Eneolithc Caucasus, which suggests gene flow into the former from a more westerly steppe source than, say, Khvalynsk from the Samara region. Using these reference samples, the inferred ratio of steppe admixture in Armenia_ChL is around 15%, which I think makes sense, more or less, considering its position in both of the PCA above.

Armenia_EBA_I1658 0.862±0.050
Sredny_Stog_I6561 0.138±0.050
chisq 17.038
tail prob 0.148174
Full output
Armenia_EBA_I1658 0.836±0.065
Sredny_Stog_I6561 0.164±0.065
chisq 13.813
tail prob 0.312808
Full output

The presence of a significant, unambiguous signal of steppe ancestry in a group from a rich archeological site in Chalcolithic Transcaucasia might be very important in the context of the Proto-Indo-European (PIE) homeland debate. That’s because it suggests the movement of peoples potentially speaking dialects of PIE from the Eneolithic Pontic-Caspian steppe, the main candidate for the PIE homeland based on historical linguistics data, into cultural hubs south of the Caucasus, which may have acted as early dispersal points for Indo-European languages into other parts of the Near East, such as Anatolia. Admittedly, though, I’m still a fan of the Balkan route for the introduction of Hittite and other Anatolian languages into Anatolia, despite recent claims in scientific literature that this scenario wasn’t corroborated by ancient DNA (see here).
Lazaridis et al., Genomic insights into the origin of farming in the ancient Near East, Nature volume 536, pages 419–424 (25 August 2016), DOI: https://doi.org/10.1038/nature19310
See also…
Yamnaya: home-grown


2018 November 26 Rocket Launch as Seen from the Space Station…

2018 November 26

Rocket Launch as Seen from the Space Station
Video Credit: ISAA, NASA, Expedition 57 Crew (ISS);
Processing: Riccardo Rossi (ISAA, AstronautiCAST); Music: Inspiring Adventure Cinematic Background by Maryna

Explanation: Have you ever seen a rocket launch – from space? A close inspection of the featured time-lapse video will reveal a rocket rising to Earth orbit as seen from the International Space Station (ISS). The Russian Soyuz-FG rocket was launched ten days ago from the Baikonur Cosmodrome in Kazakhstan, carrying a Progress MS-10 (also 71P) module to bring needed supplies to the ISS. Highlights in the 90-second video (condensing about 15-minutes) include city lights and clouds visible on the Earth on the lower left, blue and gold bands of atmospheric airglow running diagonally across the center, and distant stars on the upper right that set behind the Earth. A lower stage can be seen falling back to Earth as the robotic supply ship fires its thrusters and begins to close on the ISS, a space laboratory that is celebrating its 20th anniversary this month. Currently, three astronauts live aboard the Earth-orbiting ISS, and conduct, among more practical duties, numerous science experiments that expand human knowledge and enable future commercial industry in low Earth orbit.

∞ Source: apod.nasa.gov/apod/ap181126.html

HiPOD (25 November 2018): Crater Floor Deposits Near Lyot…

HiPOD (25 November 2018): Crater Floor Deposits Near Lyot Crater

   – Alt: 305 km, less than 5 km across.

NASA/JPL/University of Arizona

Vanadinite | #Geology #GeologyPage #Mineral Locality: Mibladen,…

Vanadinite | #Geology #GeologyPage #Mineral

Locality: Mibladen, Midelt, Khenifra Province, Morocco

Size: 5 x 4.2 x 2.7

Photo Copyright © Saphira Minerals

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Malachite| #Geology #GeologyPage #Mineral Locality: Kolwesi…

Malachite| #Geology #GeologyPage #Mineral

Locality: Kolwesi Mine, Katanga, Democratic Republic of the Congo

Size: 4.5 × 3 × 0.7 cm

Photo Copyright © Geo-Trader Minerals /e-rocks.com

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Ice cave in the volcano mutnovsky, Russia #Geology #GeologyPage…

Ice cave in the volcano mutnovsky, Russia #Geology #GeologyPage #Russia

Mutnovsky is a complex volcano located in the southern part of Kamchatka Peninsula, Russia. It is one of the most active volcanoes of southern Kamchatka; the latest eruption was recorded in 2000. At the foot of the Mutnovsky lies a geyser field, popularly known as the Lesser Valley of Geysers.

The Ice Cave Located on a slope of the peninsula’s Mutnovsky volcano.

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Prehistoric Pottery Photoset 5, Devizes Museum, Wiltshire, 17.11.18.

Prehistoric Pottery Photoset 5, Devizes Museum, Wiltshire, 17.11.18.

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Prehistoric Pottery Photoset 6, Devizes Museum, Wiltshire, 17.11.18.

Prehistoric Pottery Photoset 6, Devizes Museum, Wiltshire, 17.11.18.

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Electric Eye Bathing in light at the back of the eye, the…

Electric Eye

Bathing in light at the back of the eye, the retina is home to millions of retinal ganglion cells (RGCs), ready to carry electrical impulses – with information about the outside world – to the brain. In this lab-grown retinal organoid, a sort of biological ‘model’ of the retina, stringy bundles of artificially-coloured RGCs stretch out (red). They use spiky growth cones (coloured green) to feel their way, much like the real optic nerve when it first develops towards the brain. Grown from human pluripotent stem cells, these organoids may help to test treatments for eyes damaged by conditions like glaucoma. In the future, it might also be possible to grow replacement RGCs from a patient’s own stem cells, restoring sight by plugging these wiry connectors back in.

Written by John Ankers

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https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...