воскресенье, 4 ноября 2018 г.

6,000-year-old axe discovered at Mount Vernon

On October 12, 2018, a group of students and teachers participating in an archaeology field trip to Mount Vernon helped to discover a stone axe head dating back to the fourth millennia BCE. The axe is roughly seven inches long and three inches wide. Similar axes date to the Archaic Period of Virginia’s history (4,500-8,000 years ago) and would have been an important part of the Native American toolkit roughly 6,000 years ago. The group made this archaeological discovery at Mount Vernon’s African American cemetery, which oral history suggests was the resting place for enslaved individuals and possibly some of their freed descendants.











6,000-year-old axe discovered at Mount Vernon
Greenstone full grooved (4/4) flat cobble axe, Middle Archaic
[Credit: Melissa Wood/Mount Vernon]

The axe is particularly interesting because it represents the skill and craftsmanship of the maker. To create this axe, a craftsperson worked a river cobble by first “chipping” it with a hammer stone to create a cutting edge along the face of the axe. The burgeoning tool was then hammered with a harder stone to create a smoother cutting surface by removing smaller amounts of the raw stone from the axe. These surfaces appear to have been ground, or smoothed, one final time through the use of a hard grinding stone. Finally, a groove was pecked along the backend of the axe head. This groove would have facilitated the attachment of a wooden handle to the axe for its use in wood cutting.
“The axe provides a window onto the lives of individuals who lived here nearly 6000 years ago,” said Sean Devlin, Mount Vernon’s curator of archaeological collections. “Artifacts, such as this, are a vital resource for helping us learn about the diverse communities who shaped this landscape throughout its long history.”
The discovery took place along the ridgeline upon which the African American cemetery sits, which was used by communities of Virginia Indians as long ago as 8,000 years ago, and continuing for several thousand years afterwards based upon the archaeological evidence. While the site appears to have been continually occupied over this period, it was not necessarily a “village” site. Rather, the location was probably one of many temporary stopping over points for a community as they traveled along the river or exploited the resources of the area.
For Mount Vernon’s archaeologists, artifacts such as this axe help us interpret the daily lives of people in the past. Its archaeology program maintains an electronic database where data is recorded about every artifact recovered and where it was found. After cataloging objects, Mount Vernon’s team cleans, preserves, and stores all of our artifacts here on-site so they are available for researchers. The axe will join Mount Vernon’s rich archaeology collection of more than 50,000 artifacts cataloged from this site alone as the staff continue to learn more about and document the long history of human occupation at Mount Vernon.  For more information about Mount Vernon’s archaeology program, please visit http://www.mountvernon.org/archaeology.


Author: Mary Wadland | Source: The Zebra [October 31, 2018]



TANN



Archive


Launch of global effort to read genetic code of all complex life on earth

The Earth BioGenome Project (EBP), a global effort to sequence the genetic code, or genomes, of all 1.5 million known animal, plant, protozoan and fungal species on Earth, officially launches today (1 November) as key scientific partners and funders from around the globe gather in London, UK to discuss progress in organising and funding the project.











Launch of global effort to read genetic code of all complex life on earth
Launch of global effort to read genetic code
of all complex life on earth

The EBP will ultimately create a new foundation for biology to drive solutions for preserving biodiversity and sustaining human societies.


The EBP aims to sequence, catalogue and categorise the genomes of all of Earth’s eukaryotic biodiversity over a period of ten years. The estimated cost of the EBP is $4.7 billion. Accounting for inflation, the Human Genome Project today would cost $5 billion.


The EBP is made possible by recent and future advances in sequencing and information technology that will enable the reading and interpretation of tens of thousands of species’ genomes each year by partner institutions across the globe.


A greater understanding of Earth’s biodiversity and the responsible stewarding of its resources are among the most crucial scientific and social challenges of the new millennium. The overcoming of these challenges requires new scientific knowledge of evolution and interactions among millions of the planet’s organisms.


Currently, fewer than 3,500, or about 0.2 per cent of all known eukaryotic species have had their genome sequenced, with fewer than 100 at reference quality. Sequencing all known eukaryotic genomes, thousands at reference quality, will revolutionise our understanding of biology and evolution, bolster efforts to conserve, help protect and restore biodiversity, and in return create new benefits for society and human welfare.


The EBP has made extraordinary progress in the last year leading up to the official launch. The initial stages of the EBP has served as an organizing glue for existing large-scale genome projects and their partnering institutions on eukaryotic species around the globe. Toward this end, 17 institutions from across the globe, including the USA, United Kingdom, China, Germany, Denmark, Australia and Brazil, have signed a Memorandum of Understanding that commits each institution to work together towards the common goals of the project. It is expected that additional partner institutions, organisations and communities will join as the project progresses.



The amount of biological data that will be collected and produced from this project is expected to be on the exascale; more than the data accumulated by Twitter, YouTube or astronomy. The project’s participants have agreed in the EBP Memorandum of Understanding that data will be stored in public domain databases and access will be open to all for research purposes.


This project will build on recent achievements of sequencing sets of species’ genomes for the first time. For example, the Vertebrate Genomes Project, Chaired by Erich Jarvis of Rockefeller University, aims to sequence the genetic code of all 66,000 extant vertebrates, released the genomes of 14 species, including bat and fish species, the Canadian Lynx and Kakapo.


The BGI (Shenzhen, China) is also playing a major role in the project by leading the effort to sequencing 10,000 plant genomes and the Global Ant Genomes Alliance, which aims to sequence around 200 ant genomes. Similarly, the USDA is launching an effort to sequence 100 genomes of agriculturally important insects and mites. In total, there are now 15 scientific communities and national and regional projects that are affiliated with the EBP.


To mark the 25th anniversary of the Wellcome Sanger Institute, the Institute and its collaborators sequenced the genomes of 25 species found in the United Kingdom (UK) for the first time, including red and grey squirrels, the European robin, Fen raft spider and blackberry. The completed genome sequences will lead to future studies to understand the biodiversity of the UK and aid the conservation and understanding of UK species.


The Sanger Institute will lead the UK effort of the EBP, and with its partners, and plans to sequence all 66,000 eukaryotic species across the British Isles, in a new project known as the Darwin Tree of Life Project. Sanger has committed to creating a new programme of research, called the Tree of Life programme, to fulfil this mission and will work alongside partners at the Natural History Museum in London, Royal Botanic Gardens, Kew, Earlham Institute, EMBL-EBI and Edinburgh Genomics at the University of Edinburgh. The EBP will help coordinate this effort with other affiliated projects to help reduce redundancy and maximize resources.


“Globally, more than half of the vertebrate population has been lost in the past 40 years, and 23,000 species face the threat of extinction in the near future. Using the biological insights we will get from the genomes of all eukaryotic species, we can look to our responsibilities as custodians of life on this planet, tending life on Earth in a more informed manner using those genomes, at a time when nature is under considerable pressure, not least from us,” says Professor Sir Mike Stratton, Director of the Wellcome Sanger Institute.


“When the Human Genome Project began 25 years ago, we could not imagine how the DNA sequence produced back then would transform research into human health and disease today. Embarking on a mission to sequence all life on Earth is no different. From nature we shall gain insights into how to develop new treatments for infectious diseases, identify drugs to slow ageing, generate new approaches to feeding the world or create new bio materials,” says Sir Jim Smith, Director of Science at Wellcome.


Source: Wellcome Trust Sanger Institute [November 01, 2018]



TANN



Archive


Bee diversity and richness decline as anthropogenic activity increases, confirm...

Changes in land use negatively affect bee species richness and diversity, and cause major shifts in species composition, reports a recent study of native wild bees, conducted at the Sierra de Quila Flora and Fauna Protection Area and its influence zone in Mexico.











Bee diversity and richness decline as anthropogenic activity increases, confirm scientists
Bumblebee of the species Bombus ephippiatus Say, 1837 [Credit: Alejandro Munoz-Urias,
Alvaro Edwin Razo Leon]

Having registered a total of 14,054 individual bees representing 160 species, 52 genera, and five families over the span of a year, the scientists conclude that the studied preserved areas demonstrated “significantly greater” richness and diversity.
In their paper, published in the open-access Journal of Hymenoptera Research, a research team from the University of Guadalajara, Mexico, led by Alejandro Muñoz-Urias, compare three conditions within the tropical dry forest study site: preserved vegetation, an agricultural area with crops and livestock, and an urbanised area.


The researchers confirm earlier information that an increase in anthropogenic disturbances leads to a decrease in bee richness and diversity. While availability of food and nesting sites are the key factors for bee communities, changes in land use negatively impact flower richness and floral diversity.











Bee diversity and richness decline as anthropogenic activity increases, confirm scientists
Aztecanthidium xochipillium (Michener and Ordway, 1964). This bee is known only from Mexico
[Credit: Alejandro Munoz-Urias, Alvaro Edwin Razo Leon]

Therefore, turning habitats into urbanised or agricultural sites significantly diminishes the populations of the bees which rely on specific plants for nectar and pollen. These are the species whose populations are threatened with severe declines up to the point of local extinction.
According to their data, about half of the bees recorded were Western honey bees (49.9%), whereas polyester bees turned out to be the least abundant (1.2 %).


On the other hand, some generalist bees, which feed on a wide range of plants, seem to thrive in urbanised areas, as they take advantage of people watering wild and ornamental plants at times where draughts might be eradicating native vegetation.











Bee diversity and richness decline as anthropogenic activity increases, confirm scientists
Tropical dry forest in the dry (left) and rainy season (right) [Credit: Alejandro Munoz-Urias,
Alvaro Edwin Razo Leon]

“That is the reason why bees that can use a wide variety of resources are often able to compensate when circumstances change, although some species disappear due to land use changes,” explain the scientists.
In conclusion, the authors recommend that the tropical dry forests of both the study area and Mexico in general need to be protected in order for these essential pollinators to be conserved.


“Pollinators are a key component for global biodiversity, because they assist in the sexual reproduction of many plant species and play a crucial role in maintaining terrestrial ecosystems and food security for human beings,” they remind.


Source: Pensoft Publishers [November 01, 2018]



TANN



Archive


Early Byzantine mosaic floor discovered in Syria’s Hama

A mosaic church floor dating back to the fifth century AD was discovered in al-Kharayeb village in Salhab area, 48 km west of Hama city.











Early Byzantine mosaic floor discovered in Syria's Hama
Credit: SANA

Speaking to SANA, Head of Antiquities Department, Abdulqader Farzat that a citizen from al-Kharayeb village in Hama western countryside informed the authorities about parts of a mosaic he found in his garden.
The authorities sent a specialized mission to the place which carried out the excavations and revealed the mosaic.











Early Byzantine mosaic floor discovered in Syria's Hama
Credit: SANA

Farzat clarified that the dimensions of the mosaic floor are 13.5 and 2.30 meters. It is decorated with geometric shapes and inscriptions in Greek that carry the date AD 412.


Source: SANA [November 01, 2018]



TANN



Archive


Rare 3,000-year-old Assyrian sculpture sells for record $31M at Christie’s

A rare, 3,000-year-old sculpture sold for $31 million at Christie’s New York Wednesday, shattering the previous world record for Assyrian art. The sculpture tripled its pre-sale estimate of $10 million, and the buyer remains anonymous.











Rare 3,000-year-old Assyrian sculpture sells for record $31M at Christie’s
The 3,000-year old relief panel depicts a deity called an apkallu or winged genius 
[Credit: Christie’s Images LTD. 2018]

The sculpted panel was excavated in the 19th century from the ruins of the Northwest Palace in Nimrud, in present-day Iraq. For years, it remained in a private library with its value unknown.


The cultural treasures of Nimrud made headlines in 2015 when ISIS occupied Mosul, 20 miles to its north, and used barrel bombs, bulldozers, power tools and sledgehammers to reduce the site to rubble.


Christie’s auction of this solid slab of gypsum depicting a seven foot-tall deity marked the first high-profile sale of an Assyrian antiquity since then.


An Englishman abroad


In 1845, a young British adventurer called Austen Henry Layard arrived in Nimrud and began excavations. Since the collapse of the Assyrian Empire towards the end of the 7th century BC, the site had remained relatively untouched and he found a wealth of archaeological gems.


At the time, Iraq was part of the Ottoman Empire, and its Turkish rulers appear to have seen no problem in Layard stripping the region of much of its heritage.


The Grand Vizier of the Ottoman Sultan wrote a letter to Stratford Canning, the then British ambassador, which — in the words of its recipient — authorized Layard to “excavate and export to your heart’s content.”











Rare 3,000-year-old Assyrian sculpture sells for record $31M at Christie’s
Engraving depicting Austen Henry Layard at work, removing a statue of a great winged bull from 
an Assyrian site in Iraq [Credit: Universal History Archive/UIG via Getty Images]

Layard did exactly that. He sent the majority of the antiquities to London, where they now form the core of the British Museum’s Assyrian collection.


Layard’s incredible findings also caught the attention of American missionaries.


The Assyrian empire is referenced in the Old Testament, but its ruins had not been located. The monuments confirmed its existence and, to the missionaries, “proved that the Bible was real and not a work of fiction,” said Max Bernheimer, Christie’s international head of antiquities. “It fed the religious fervor of the time,” he added.


In 1859, one of those missionaries — Henri Byron Haskell — acquired three relief panels on behalf of his friend Joseph Packard, a professor at Virginia Theological Seminary, near Washington DC. The seminary provides postgraduate education to members of the Episcopal Church.


The panels were a bargain — bought for $75 each, with most of that cost covering the shipping fees.


Close up views of the 3,000-year old relief panel 


[Credit: Christie’s Images LTD. 2018]


Since their arrival, the panels have been displayed in the seminary’s library, and were primarily considered a scholarly resource rather than works of art. A routine audit in 2017, however, revealed the value of the panels and sent insurance premiums skyrocketing to $70,000 a year.


That prompted the decision to sell one. The proceeds of the sale will support the preservation and study of the two remaining panels, and benefit the seminary’s scholarship fund.


In the lead up to the auction, the Iraqi Ministry of Culture called for the panel to be returned to Iraq, and activists had suggested a protest outside Christie’s during the sale.


A spokesman for Christie’s said that while the auction house was “sensitive to claims for restitution by source countries,” it had been reassured by law enforcement authorities that there was no legal basis for a cultural property claim in this case.


A winged genius


The Northwest Palace was the crowning architectural achievement of King Ashurnasirpal II, who ruled from 883 to 859 BC. When complete, it was the largest and most lavishly decorated building in the Assyrian Empire. “Ashurnasirpal was the big kahuna, as it were, of his age,” said Bernheimer.











Rare 3,000-year-old Assyrian sculpture sells for record $31M at Christie’s
Based on traces of pigment discovered on other relief panels, Christie’s New York has created a digital reconstruction
 to show what the rare Assyrian relief panel it is auctioning might have originally looked like 
[Credit: Christie’s Images LTD. 2018]

The king expanded his territory by mounting a series of ruthless military campaigns and established a new capital at Nimrud — called Kalhu at the time. Ashurnasirpal fitted out his new city with a citadel, defensive walls, four palaces, temples and townhouses, using the wealth that flowed in from his conquests, and the labor of subjugated slaves.


The Northwest Palace’s interior walls were lined with more than 400 sculpted relief panels. The winged genius was the most common design, but some panels depicted Ashurnasirpal’s empire-building conquests, religious events, royal hunting scenes and courtly banquets.


Panels like the one being auctioned were designed to “impress and overwhelm,” said Bernheimer. “Standing next to it, you feel the power,” he added.


Towering and richly-detailed, the carved figure is depicted in profile and the face of the muscular, bearded god resembles that of Ashurnasirpal.











Rare 3,000-year-old Assyrian sculpture sells for record $31M at Christie’s
The cuneiform inscription is repeated on almost all the 400 plus panels that lined the palace’s walls. It tells of
Ashurnasirpal’s ancestry, his military triumphs, the extent of his empire and the construction
of the Northwest Palace 
[Credit: Christie’s Images LTD. 2018]

A band of text written in cuneiform — one of the earliest systems of writing — runs across the center of the relief. It tells of Ashurnasirpal’s ancestry, his military triumphs, the extent of his empire and the construction of the Northwest Palace.
This inscription was “repeated across nearly all the panels that lined the palace walls,” said Bernheimer. It’s a flattering account:


“Ashurnasirpal, the exalted prince, the one who fears the great gods, the fierce monarch, the one who conquers cities and mountains in their entire extent, the king of lords, who destroys dangerous (enemies), crowned with splendor, fearless in battle, the merciless hero …”


This particular winged genius adorned a space that archaeologists call Room S, which connected a public central courtyard to the king’s private rooms.











Rare 3,000-year-old Assyrian sculpture sells for record $31M at Christie’s
A reconstruction of King Ashurnasirpal’s palaces in Nimrud [Credit: Historical Picture Archive/
Corbis via Getty Images]

“It seems to have been an intimate area, rather than an audience chamber,” said Bernheimer.


Along the walls, the winged genius was repeated over and over and over again.


“Whatever was happening in Room S,” said Bernheimer, “must have been considered very important to require so much protection from the gods.”


Author: Sarah Lazarus | Source: CNN [November 01, 2018]



TANN



Archive


Ancient statues, graves unearthed in Greek field

Greece’s Culture Ministry says a Greek farmer’s recent discovery of a fragment of an ancient statue while tilling his field has yielded three more statues and several graves in the past month.











Ancient statues, graves unearthed in Greek field
Credit: Greek Ministry of Culture

Archaeologists have been busy since mid-October, digging part of a field near the central Greek town of Atalanti, 150 kilometres northwest of Athens.


Ancient statues, graves unearthed in Greek field










Ancient statues, graves unearthed in Greek field
Credit: Greek Ministry of Culture

The dig began after the farmer found the torso of an ancient kouros (young man) and immediately alerted the authorities.


Ancient statues, graves unearthed in Greek field










Ancient statues, graves unearthed in Greek field
Credit: Greek Ministry of Culture

The ministry said Saturday that a total of four large fragments of life-size limestone statues of young men have been found, along with a triangular statue base.
Deeper down, seven graves with several unspecified findings have been unearthed, likely part of a larger cemetery.


Source: The Associated Press [November 03, 2018]



TANN



Archive


Krennerite | #Geology #GeologyPage #Mineral Locality: Sacaramb…


Krennerite | #Geology #GeologyPage #Mineral


Locality: Sacaramb (Nagyag), Hunedoara County, Romania


Size: FOV: 1 mm


Photo Copyright © Stone Ásványfotós


Geology Page

www.geologypage.com

https://www.instagram.com/p/BpwmMisF9wd/?utm_source=ig_tumblr_share&igshid=f9tmppbr9pvs


Downpatrick Head, County Mayo,Ireland | #Geology #GeologyPage…


Downpatrick Head, County Mayo,Ireland | #Geology #GeologyPage #Ireland


Just a few miles north of Ballycastle village, County Mayo, is the the windswept outcrop of Downpatrick Head. This is the perfect place to park up and stretch your legs with an invigorating coastal walk.


Read more & More Photos: http://www.geologypage.com/2016/05/downpatrick-head-county-mayo-ireland.html


Geology Page

http://www.geologypage.com

https://www.instagram.com/p/BpwqMXVF6E0/?utm_source=ig_tumblr_share&igshid=yv5idxpebzq9


Fatty Foam Deep inside a rabbit’s lung, something bad is…


Fatty Foam


Deep inside a rabbit’s lung, something bad is happening. The red region is caseum – a cheese-like collection of dead and dying cells caused by infection with Mycobacterium tuberculosis bacteria, which cause the serious lung disease tuberculosis. Also packed into the caseum are fat-filled immune cells known as foam cells – it’s the fat droplets inside them that are picked up by the red dye used to stain this sample. Foam cells are also found in the fatty artery-blocking plaques in heart and cardiovascular disease, where they’re packed with the ‘bad’ cholesterol that’s linked to heart disease. But the foam cells in tuberculosis-infected lungs appear to be packed with a different type of fat altogether, known as triglycerides. The discovery points to completely different biological pathways at work in the two diseases, suggesting that stopping triglyceride manufacture in these foam cells could lead to entirely new ways to treat tuberculosis.


Written by Kat Arney



You can also follow BPoD on Instagram, Twitter and Facebook


Archive link


2018 November 4 Flying Saucer Crash Lands in Utah Desert Image…


2018 November 4


Flying Saucer Crash Lands in Utah Desert
Image Credit: USAF 388th Range Sqd., Genesis Mission, NASA


Explanation: A flying saucer from outer space crash-landed in the Utah desert after being tracked by radar and chased by helicopters. The year was 2004, and no space aliens were involved. The saucer, pictured here, was the Genesis sample return capsule, part of a human-made robot Genesis spaceship launched in 2001 by NASA itself to study the Sun. The unexpectedly hard landing at over 300 kilometers per hour occurred because the parachutes did not open as planned. The Genesis mission had been orbiting the Sun collecting solar wind particles that are usually deflected away by Earth’s magnetic field. Despite the crash landing, many return samples remained in good enough condition to analyze. So far, Genesis-related discoveries include new details about the composition of the Sun and how the abundance of some types of elements differ across the Solar System. These results have provided intriguing clues into details of how the Sun and planets formed billions of years ago.


∞ Source: apod.nasa.gov/apod/ap181104.html


Bachwen Burial Chamber, Clynnog Gawres, North Wales, 21.10.18.









Bachwen Burial Chamber, Clynnog Gawres, North Wales, 21.10.18.



Source link


Penarth Prehistoric Burial Chamber, Aberdesach, North Wales, 21.10.18.







Penarth Prehistoric Burial Chamber, Aberdesach, North Wales, 21.10.18.


Source link


Editing nature: Scientists call for careful oversight of environmental gene editing

In Burkina Faso, the government is considering the use of genetically modified mosquitoes to eradicate malaria. In Nantucket, Mass., officials are looking at gene editing as a tool in the fight against Lyme disease. And scientists are using gene technology to adapt coral to changing ocean conditions from the Caribbean to the Great Barrier Reef.











Editing nature: Scientists call for careful oversight of environmental gene editing
Credit: Yale University

Yet for all the breathtaking promise of these technologies, there remain profound concerns about the potential unintended consequences of releasing gene-edited organisms into the environment—and a lack of governance oversight.


In a new paper published in Science, an interdisciplinary group led by Yale researchers argues for new global governance to assure a neutral and informed evaluation of the potential benefits and risks of gene editing. They argue that the complex nature of these technologies requires, on a case-by-case basis, careful and judicious review—a decision-making process that must include local communities that would feel the biggest and most immediate effects.


“The biggest risk right now with this technology is the uncertainty associated with it,” said Natalie Kofler, an associate research scientist at the Yale School of Forestry & Environmental Studies (F&ES) and lead author of the paper.


“In places like Burkina Faso, for instance, it is being touted as a silver bullet to get rid of malaria. But these technologies also have the potential to forever change the genetic makeup of species, or even drive certain species to extinction. Lack of global governance puts our planet at risk.”


In the paper, the authors propose the formation of a new coordinating global body with the power to convene communities, developers, governmental organizations, and NGOs to assure careful and inclusive deliberation over all proposals. Such an organization would provide neutral oversight over decision-making and integrate diverse expertise and perspectives, including participants from impacted local communities.


“Confronting this challenge goes beyond just the inclusion of empirical, scientific data, to also bring in value systems, ethics, and relationships with nature, relationships with technology, and historically marginalized voices to make a fully informed decision,” said Kofler. “Our proposal provides a blue-print on how to enact a new model of governance, one built on the integration of empirical and normative inputs, that includes diverse expertise and worldviews.”


The paper was inspired by the Editing Nature Summit, chaired by Kofler and hosted at Yale in the spring of 2017. During the two-day event, participants from a range of disciplines grappled with the ethical questions surrounding the development and deployment of gene editing technologies into the environment. Of critical importance, they concluded, are the questions of who gets to decide what technologies are used and the process by which they reach that decision.


The co-authors, who all participated in the summit, represent 12 different academic institutions and more than dozen disciplines, including ecology, genetics, philosophy, policy, and journalism.


In the paper, they looked in particular at CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) gene editing and other related technologies like gene drives, which are designed to spread genetic changes—including traits such as infertility—through populations of species.


But if these technologies have the potential to eliminate threats to public health or ecosystems, little is known about potential side effects, such as unwanted mutations and new evolutionary resistance.


“There are many proposals to release gene-edited organisms into the wild and even actively drive them into the genomes of native wild populations to address a wide range of environmental issues,” said Oswald Schmitz, the Oastler Professor of Population and Community Ecology at F&ES and director of the Yale Institute for Biospheric Studies.


“But this is all proceeding at a heady pace with very little discussion with potentially affected communities. Formal safeguards are needed to ensure that these well-intentioned technologies don’t unintentionally spread globally to destroy ecosystems and human welfare and cultures that rely on them.”


Complicating the discussion is the fact that, in some cases, the proposed gene-editing strategies could mitigate very real public health threats, such as the life-or-death consequences of malaria in parts of Africa, said James Collins, the Virginia M. Ullman Professor of Natural History and the Environment at Arizona State University and co-author of the paper.


“The burden of those infectious diseases such as malaria or the Zika virus is a heavy one for communities to bear,” said Collins, who co-chaired a National Academy of Sciences committee that evaluated responsible use of gene editing technology. “And it’s a consideration that really has to be taken into account as individuals think about whether these technologies should be developed and then released into the environment. At the same time, in the area of unintended consequences, you really want to have done the very best work possible, the very best analysis possible, in terms of risk assessment.


“It’s just really so important that we give every consideration to what the larger implications would be of releasing these organisms,” he added. “It’s also vital that we rely on context and history to guide us in terms of being willing to move ahead with these important areas of research, but also that we do it in a way that is cautious, judicious, and transparent.


“That way, individuals and society can then make an informed judgment as to which of these technologies should be deployed and how that should be done.”


Author: Kevin Dennehy | Source: Yale University [November 01, 2018]



TANN



Archive


Barn swallows may indeed have evolved alongside humans

The evolution of barn swallows, a bird ubiquitous to bridges and sheds around the world, might be even more closely tied to humans than previously thought, according to new study from the University of Colorado Boulder.











Barn swallows may indeed have evolved alongside humans
Barn swallows on a wire [Credit: Matt Davis/Macaulay Library/Cornell Lab of Ornithology]

The research, published this week in Molecular Ecology, offers preliminary insight suggesting that the barn swallow and its subspecies evolved alongside–but independently from–humans. These new results make it one of the only known species, in addition to microscopic organisms like bacteria or viruses, to have developed in such a way, upending previous assumptions that barn swallows evolved prior to human settlement.


“Humans could be a really big part of the story,” said Rebecca Safran, a co-author of the study and an ecology and evolutionary biology (EBIO) associate professor at CU Boulder. “There’s very few studies that can point to the exact influence of humans, and so here, this coincidence of human expansion and permanent settlement and the expansion of a group that relies really, really heavily on humans is compelling.”


Barn swallows are found across the northern hemisphere and are characterized by their mud-cup nests that are built nearly exclusively on human-made structures. Despite their prevalence, however, not much is known about their evolutionary history, the timing of their expansion from northern Africa (where they originated) or how the six subspecies evolved so physically and behaviorally different yet remain almost genetically identical.


Previous studies looked into these questions and found that the different subspecies split early, well before human settlement. This new study, however, gave the topic a fresh look by examining the whole genome of 168 barn swallows from the two sub-species farthest apart on an evolutionary scale: H. r. savignii in Egypt (a non-migratory species that lives along the Nile) and H. r. erythrogaster in North America (a species found throughout North America that migrates seasonally to South America).











Barn swallows may indeed have evolved alongside humans
Barn swallow subspecies are found throughout the northern hemisphere
[Credit: Hilary Burn & Safran lab]

These data–which are on the order of 100,000 times bigger than the previous dataset used–were then analyzed with more sophisticated computational resources and methods than previously available. This allowed researchers to get a more complete picture that places the timing of barn swallow differentiation or speciation (i.e., when the barn swallow subspecies separated) closer to that of when humans began to build structures and settlements.


“The previous studies were playing with the idea of potential impact on population sizes due to humans,” said Chris Smith, a graduate student in EBIO and the Interdisciplinary Quantitative Biology program, and the study’s lead author. “Our results suggest a much more substantial link with humans.”


These new preliminary findings also suggest that this evolutionary link may have been forged through a “founder event,” which is when a small number of individuals in a species take over a new environment and are able to expand their new population there thanks to an availability of resources and an absence of competitors. For barn swallows, this event may have occurred rapidly when they moved into a new, relatively empty environment: alongside humans.


“Everyone is always wondering how do you study speciation? It’s been viewed as this long-term, million-year (process), but in barn swallows, we are not talking about differentiation within several thousands of years,” said Safran. “Things are really unfolding rather rapidly.”


Smith concurred: “It’s interesting to study speciation in the beginning steps.”


Source: University of Colorado at Boulder [November 01, 2018]



TANN



Archive


Researchers solve the mystery of the bird from Atlantis

The world’s smallest flightless bird can be found on Inaccessible Island in the middle of the South Atlantic. Less than 100 years ago, researchers believed that this species of bird once wandered there on land extensions now submerged in water, and therefore named it Atlantisia. In a new study published in Molecular Phylogenetics and Evolution, the researchers have now shown that the ancestors of the Atlantisia flew to Inaccessible Island from South America about 1.5 million years ago.











Researchers solve the mystery of the bird from Atlantis
The Inaccessible Island Rail, known now as Atlantisia rogersi, needs a name change after researchers linked the tiny bird
to a species in South America. The researchers believe the bird made its journey to the South Atlantic island, the
only place in the world where this species of rail lives, in a single migration 1.5 million years ago
[Credit: Peter G. Ryan]

The Inaccessible Island rail (Atlantisia rogersi) is endemic and can only be found on Inaccessible Island. It has no natural enemies on the island and runs around like a small rodent in the vegetation. Biologist Martin Stervander, who now works at the University of Oregon, USA, conducted a study together with researchers from South Africa and Portugal during his time at Lund University.


Among other things, they analysed the DNA of the Inaccessible Island rail using modern sequencing techniques. In this way, the researchers were able to determine that the bird’s closest now living relatives are the dot-winged crake in South America and the black rail found in both South and North America. It probably also has a relative on the Galápagos.


“It seems that rail birds are extremely good at colonising new remote locations and adapting to different environments. Despite great distances, the environments may be similar and, through convergent evolution, distant relatives may in fact become so similar that taxonomists are tricked into drawing erroneous conclusions”, says Martin Stervander.


A theory that proved to be wrong came from Percy Lowe when he described the Inaccessible Island rail almost 100 years ago. Lowe classified the bird in its own genus and drew the conclusion that its inability to fly was a very old trait, and that it colonised Inaccessible Island on foot by walking on land extensions and across continents that later disappeared into the depths of the ocean.


“The fact that Lowe’s theory was incorrect came as no surprise. Using DNA, we can prove that the ancestors of the Inaccessible Island rail flew to Inaccessible Island from South America about 1.5 million years ago”, says Martin Stervander, continuing:


“The bird has not had any natural enemies on the island and has not needed to fly in order to escape predators. Its ability to fly has therefore been reduced and ultimately lost through natural selection and evolution over thousands of years.”


Not being able to fly means that the Inaccessible Island rail does not waste energy on something that is unnecessary in order to survive and propagate.


“Our discovery focuses on the importance of continuing to prevent enemies of the Inaccessible Island rail from being introduced on the island. If that happens, it might disappear”, concludes Bengt Hansson, professor at Lund University and one of the researchers behind the study.


Source: Lund University [November 01, 2018]



TANN



Archive


Lab 3-D scans human skeletal remains dating back to the American Civil War

In the Virtual Curation Laboratory, the lab’s director, Bernard Means, Ph.D., is holding a realistic-looking 3-D printed replica of a human skull fragment that was dented by a bomb explosion during the Civil War.











Lab 3-D scans human skeletal remains dating back to the American Civil War
VCU professor Bernard Means, Ph.D., displays a 3-D printed replica of a skeletal hand with a bullet hole that
is part of the collection of the National Museum of Health and Medicine [Credit: Brian McNeill/VCU]

“For the rest of this person’s life, they had seizures because of the [injury],” Means said. “In fact, they died because they fell into water during a seizure and they drowned.”


Means 3-D scanned the skull fragment during a recent visit to the National Museum of Health and Medicine as part of an agreement with the museum to 3-D scan items, primarily historic bone specimens, from the Civil War through World War I.


The museum, located in Silver Spring, Maryland, was established during the Civil War as the Army Medical Museum, a center for the collection of specimens for research in military medicine and surgery.


VCU’s Virtual Curation Laboratory specializes in the 3-D scanning and 3-D printing of historic and archaeological objects, and is part of the School of World Studies in the College of Humanities and Sciences.











Lab 3-D scans human skeletal remains dating back to the American Civil War
VCU’s Virtual Curation Laboratory has 3-D scanned and 3-D printed a number of specimens from the National
Museum of Health and Medicine’s collection, including a mummified ear attached to skull fragment
 that was donated in the early 1900s [Credit: Brian McNeill/VCU]

So far, Means and his students have scanned and printed replicas of roughly 30 items in the museum’s collection.


Among the highlights are a leg bone that healed poorly after being shot during the Civil War, a skull with a hole in it from a Civil War surgeon’s trepanation procedure, a mummified ear attached to a skull fragment that was donated in the early 1900s, and a late 19th-century skeletal hand with a bullet hole from an area in the Midwest designated for Native American resettlement. None of the remains being 3-D scanned is Native American.


“In the National Museum of Health and Medicine’s collection, they have pathological specimens of people who were injured in combat, going back to the Civil War. Some of whom survived, some of whom did not,” Means said. “It is one of the best collections of battlefield trauma specimens in the world.”


By 3-D scanning items at the museum, the Virtual Curation Laboratory is aiming to make the collection more accessible to researchers and the public.


“They want to get 3-D scans of items in their collection and they want to get them out there so the public can see them and also so that researchers can access them,” Means said.











Lab 3-D scans human skeletal remains dating back to the American Civil War
Isabel Griffin, a senior communication arts major and Virtual Curation Laboratory manager,
paints a 3-D-printed replica of a bone fragment from the collection of the National
Museum of Health and Medicine [Credit: Brian McNeill/VCU]

For public programs, 3-D printed replicas allow visitors such as school groups to get a more hands-on experience with a museum’s collection, he said.


“If a school group visits, [the museum] can’t pass around human skeletal remains,” he said. “But they can pass around 3-D printed replicas.”


The collection is of particular interest to researchers focused on the history of battlefield trauma, as well as forensic anthropology.


Terrie Simmons-Ehrhardt, a researcher in the Department of Forensic Science who studies forensic anthropology, specifically in forensic craniofacial identification and 3-D osteology, has been collaborating with Means on 3-D scanning bone specimens with a goal of creating a digital forensic osteology collection that would be accessible to anyone doing forensic research or education.


“I am assisting Bernard with the surface scanning of NMHM osteological specimens and also assisting the museum with processing of micro-CT and CT scans of some specimens,” Simmons-Ehrhardt said. “We are generating high-resolution 3-D models to be shared online that can be interacted with either online or in 3-D software, as well as 3-D printed.”


Author: Brian Mcneill | Source: Virginia Commonwealth University [November 01, 2018]



TANN



Archive


Featured

Полет на параплане с обрыва на мысу Куяльницкого лимана, соленого озера. Экстремальный развлекательный полет проводится для любителей. ...

Popular