It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, May 12, 2020
Anti-Semitism in the US hits 4-decade high: report
2019 was the worst year for anti-Semitic attacks since the Anti-Defamation League began keeping records. This included a massive uptick in violent assaults.
Anti-Semitic incidents in the United States hit a four-decade high in 2019, according to the latest report from the Anti-Defamation League (ADL), one of the US' oldest and largest Jewish NGOs. The ADL's annual audit published late on Tuesday found that over 2,000 acts of assault, vandalism, and harassment had taken place – the most since the group started keeping track in 1979.
"The record number of incidents came as the Jewish community grappled with vicious and lethal antisemitic attacks against communities in Poway, Jersey City and Monsey, and a spree of violent assaults in Brooklyn," the ADL noted in its report.
Of the 96 victims of violent assaults, including five fatalities, across the US, 25 were targeted in Brooklyn alone. The area is home to many Hasidic and Ultra-Orthodox Jewish communities.
In total, there were 2,107 anti-Semitic incidents in the US, occurring in every US state except Alaska and Hawaii. This number represents a 12% increase on 2018. Overall, harassment increased by 6%, vandalism by 19%, and assault by a massive 56%.
"It's clear we must remain vigilant in working to counter the threat of violent antisemitism and denounce it in all forms, wherever the source and regardless of the political affiliation of its proponents," said Jonathan Greenblatt, the ADL's chief executive.
The annual report also highlighted that while incidents had decreased slightly at synagogues and Jewish community centers, anti-Semitism continued to increase at schools and universities.
In at least 170 cases, the motivation for the hate crimes was "anti-Israel animus" and that many Jewish school children and university students were targeted for their "real or assumed connection to Israel."
Greenblatt said one of the most important tools in fighting hate was better education about Jewish history and the Holocaust, adding that the ADL would petition state and federal governments to ensure this is included in school curriculums.
The FBI has also reported that all forms of hate crime across the US had hit a 16-year high. The bureau found that the vast majority of hate crimes in New York City targeted Jewish people, while overall the biggest increase was against the Latinx community amidst an atmosphere of anti-immigrant sentiment fomented by the incendiary rhetoric of the Trump administration.
Waiting game: testing the patience of predators and prey
Snakes and frogs appear to anticipate each other
IMAGE: A JAPANESE STRIPED SNAKE (ELAPHE QUADRIVIRGATA) AND DARK-SPOTTED FROG (PELOPHYLAX NIGROMACULATUS) STARING DOWN ANTICIPATING EACH OTHER'S NEXT MOVE view more
CREDIT: KYOTO UNIVERSITY/NOZOMI NISHIUMI
KYOTO UNIVERSITY
Kyoto, Japan -- 'Like a frog stared down by a snake', goes an old Japanese expression, descrbing an animal petrified with fear.
However, it now seems that this freeze in action may not be about fear at all, but rather a delicate waiting game of life and death.
A new report from researchers at Kyoto University's Graduate School of Science shows that this common interaction is all about patience, with each animal waiting for and anticipating its opponent's actions.
"When predator and prey face each other, it is generally thought that the initiator has the advantage that would mediate successful capture or escape," explains Nozomi Nishiumi, corresponding author of the report published in the Canadian Journal of Zoology.
"However, in cases involving snakes and frogs, they occasionally move extremely slowly -- or almost not at all. It looks like they purposely avoid taking preemptive action."
Nishiumi, together with colleague Akira Mori, examined how the animals' behaviors affected the consequences of their interaction by focusing specifically on the kinematics of the snakes' strikes and the frogs' flight behavior.
The team analyzed the movement patterns of the Japanese striped snake, Elaphe quadrivirgata, and the black-spotted pond frog, Pelophylax nigromaculatus, both in the field and in staged encounter experiments.
"In the staged encounters we wanted to look at the disadvantages of preemptive actions by analyzing the kinematic characteristics of each animal's movements," explains Nishiumi.
"The field observations, on the other hand, were designed to follow the consequences of the animals' actions and survival."
The team found that the counteractions of each animal were often effective because the initiator's actions were difficult to change once started. For example, if the snake initiated a strike action first, the frog would evade the attack because the trajectory of the strike could not be changed mid-movement, allowing the frog to escape safely while the snake spent time resetting its lunge posture.
Alternatively, if the frog first attempted an escape, the snake would start lunging immediately, and occasionally be able to adjust its strike direction in anticipation of the frog's direction of movement.
"The efficacy of this waiting tactic depends on the distance between them: the closer they are the less likely the counteraction succeeds," continues Nishiumi.
"In this regard, when approaching this critical distance, the animals appropriately switch their behaviors from waiting to taking action."
These results suggest that a game of patience occurs between the animals, providing insight on predicting the decision-making of predators and prey.
The paper "A game of patience between predator and prey: waiting for opponent's action determines successful capture or escape" appeared on 10 March 2020 in the Canadian Journal of Zoology, with doi:10.1139/cjz-2019-0164
About Kyoto University
Kyoto University is one of Japan and Asia's premier research institutions, founded in 1897 and responsible for producing numerous Nobel laureates and winners of other prestigious international prizes. A broad curriculum across the arts and sciences at both undergraduate and graduate levels is complemented by numerous research centers, as well as facilities and offices around Japan and the world. For more information please see: http://www.kyoto-u.ac.jp/en
Authors: Nozomi Nishiumi, Akira Mori
Contact: Nozomi Nishiumi PhD
National Institute for Basic Biology
5-1 Higashiyama, Myodaijichou, Okazaki, Aichi 444-8787, Japan
Can we really tell male and female dinosaurs apart?
QUEEN MARY UNIVERSITY OF LONDON
Scientists worldwide have long debated our ability to identify male and female dinosaurs. Now, research led by Queen Mary University of London has shown that despite previous claims of success, it's very difficult to spot differences between the sexes.
In the new study, researchers analysed skulls from modern-day gharials, an endangered and giant crocodilian species, to see how easy it is to distinguish between males and females using only fossil records.
Male gharials are larger in size than females and possess a fleshy growth on the end of their snout, known as a ghara. Whilst the ghara is made from soft tissue, it is supported by a bony hollow near the nostrils, known as the narial fossa, which can be identified in their skulls.
The research team, which included Jordan Mallon from the Canadian Museum of Nature, Patrick Hennessey from Georgia Southern University and Lawrence Witmer from Ohio University, studied 106 gharial specimens in museums across the world. They found that aside from the presence of the narial fossa in males, it was still very hard to tell the sexes apart.
Dr David Hone, Senior Lecturer in Zoology at Queen Mary University of London and author of the study, said: "Like dinosaurs, gharials are large, slow growing reptiles that lay eggs, which makes them a good model for studying extinct dinosaur species. Our research shows that even with prior knowledge of the sex of the specimen, it can still be difficult to tell male and female gharials apart. With most dinosaurs we don't have anywhere near that size of the dataset used for this study, and we don't know the sex of the animals, so we'd expect this task to be much harder."
In many species, males and females can look very different from each other. For example, antlers are largely only found in male deer and in peacocks, males are normally brightly-coloured with large, iridescent tail feathers whereas females are much more subdued in their colouration. This is known as sexual dimorphism and is very common within the animal kingdom. It is expected that dinosaurs also exhibit these differences, however this research suggests that in most cases this is far too difficult to tell from the skeleton alone.
Dr Hone said: "Some animals show extraordinarily high levels of sexual dimorphism, for example huge size differences between males and females. Gharials sit somewhere in the middle as they do possess these large narial fossa that can help with identification. Our study suggests that unless the differences between the dinosaurs are really striking, or there is a clear feature like the fossa, we will struggle to tell a male and female dinosaur apart using our existing dinosaur skeletons."
The new research also challenges previous studies that have hinted at differences between the sexes in popular dinosaur species such as the Tyrannosaurus rex (T. rex), and led to common misconceptions amongst the general public.
"Many years ago, a scientific paper suggested that female T. rex are bigger than males. However, this was based on records from 25 broken specimens and our results show this level of data just isn't good enough to be able to make this conclusion," Dr Hone added.
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Notes to Editors
Research publication: 'Ontogeny of a sexually selected structure in an extant archosaur Gavialis gangeticus (Pseudosuchia: Crocodylia) with implications for sexual dimorphism in dinosaurs' D Hone, J Mallon, P Hennessey, L Witmer. PeerJ
Supporting images available on request.
For a copy of the paper, please contact:
Sophie McLachlan Faculty Communications Manager (Science & Engineering) Queen Mary University of London sophie.mclachlan@qmul.ac.uk Tel: 020 7882 3787
About Queen Mary
Queen Mary University of London is a research-intensive university that connects minds worldwide. A member of the prestigious Russell Group, we work across the humanities and social sciences, medicine and dentistry, and science and engineering, with inspirational teaching directly informed by our world-leading research. In the most recent Research Excellence Framework we were ranked 5th in the country for the proportion of research outputs that were world-leading or internationally excellent. We have over 25,000 students and offer more than 240 degree programmes. Our reputation for excellent teaching was rewarded with silver in the most recent Teaching Excellence Framework. Queen Mary has a proud and distinctive history built on four historic institutions stretching back to 1785 and beyond. Common to each of these institutions - the London Hospital Medical College, St Bartholomew's Medical College, Westfield College and Queen Mary College - was the vision to provide hope and opportunity for the less privileged or otherwise under-represented. Today, Queen Mary University of London remains true to that belief in opening the doors of opportunity for anyone with the potential to succeed and helping to build a future we can all be proud of.
DNA surprises surfacing in the Atlantic: Species far from their usual southern homes
DNA scientists sampling the New Jersey shore bottle the changing ranges of marine life predicted a decade ago; Fishing DNA from seawater: a harmless, economical way to study marine animals' movements, diversity, distribution ... and perhaps abundance
THE ROCKEFELLER UNIVERSITY PROGRAMME FOR THE HUMAN ENVIRONMENT
IMAGE: BRAZILIAN COW NOSE RAY, NEVER KNOWN NORTH OF THE GULF OF MEXICO, FOUND IN THE ATLANTIC OFF NEW JERSEY BY DNA SCIENTISTS view more
CREDIT: JACQUES BURKHARDT
DNA scientists investigating new marine life migration patterns in the Atlantic Ocean surfaced the genetic traces of species far from their usual southern homes.
A species of ray -- the Brazilian cownose ray, Rhinoptera brasiliensis, and the Gulf kingfish, Menticirrhus littoralis, have been turning up when the weather turns warm in New Jersey's Barnegat Inlet, about a two hour drive south of New York City.
The ray has never before been recorded in the US north of the Gulf of Mexico; the perch-like Gulf kingfish has never before been recorded north of Chesapeake Bay, Virginia, about 250 miles (400 km) to the south.
Led by Mark Stoeckle of The Rockefeller University and published in the journal Frontiers in Marine Science, the study involved drawing seawater twice monthly for two years and testing it for genetic material -- DNA contained in cells sloughed off the slimy, gelatinous outer coating of a fish as it swims, for example, in its excretions, in tissue fragments shed in combat with a predator, or after death or injury.
Dr. Stoeckle explains that DNA degrades and disperses within a few days of an animal's departure, but lingers in the water, despite currents and tides, long enough to detect a species' passing presence.
Over two years, from spring 2017 to spring 2019, sampling was conducted at a pair of Barnegat Inlet, NJ sites within a few miles of each other -- an outer shore to sample Atlantic Ocean waters, and inside a sheltered bay.
In 2010, a Census of Marine Life program, the Future of Marine Animal Populations (FMAP), forecast changes in diversity of marine species based on available habitat and anticipated changes in water temperature.
Jesse Ausubel, Director of the Program for the Human Environment at The Rockefeller University, and CoML's co-founder, says the Brazilian cownose ray or Gulf kingfish far north of its known range fits FMAP's prediction, while noting that other explanations remain possible. For example, the animals may have simply evaded New Jersey trawl nets for years.
Found through DNA left behind off the coast New Jersey shore, the perch-like Gulf kingfish has never before been recorded north of Chesapeake Bay, Virginia, about 250 miles (400 km) to the south. With changes in the oceans owing to climate, chemical pollution, debris, noise, night-time illumination, and other factors, "this study further establishes aquatic environmental DNA (eDNA) as an innovative, inexpensive, low-impact way to monitor marine life migrations, changing ranges, diversity and distribution," says Jesse Ausubel
CREDIT
SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/
With changes in the oceans owing to climate, chemical pollution, debris, noise, night-time illumination, and other factors, Mr. Ausubel stresses, "this study further establishes aquatic environmental DNA (eDNA) as an innovative, inexpensive, low-impact way to monitor marine life migrations, changing ranges, diversity and distribution."
Says Dr. Stoeckle: "Promising work is also underway to confirm a relationship between the concentration of a species' DNA in seawater and the abundance of that species in the water. If water samples can provide an index of the number or total weight of fish of a given species in a defined ocean area, that offers a potential leap forward for sustainable fisheries and ocean management, improving the rationality with which fish quotas are set and the quality and reliability of their monitoring around the world."
Tony MacDonald, Director of Monmouth University's Urban Coast Institute, which helped initiate the work, adds: "Censusing marine fish and other animals that move typically involves costly, time-consuming surveys with specialized equipment and personnel. eDNA science is granting humanity a very old wish: an easy way to estimate the distribution and abundance of diverse fish species and other forms of aquatic life in the dark waters of rivers, lakes, and seas."
Dr. Stoeckle, who has worked with high school and college students to study New York Harbor and the Hudson River, adds that "the collection process is simple enough for supervised schoolchildren or citizen scientists on any coast anywhere to help monitor the changing ranges of all marine life." Co-author Mithun Das Mishu joined the project when he was a sophomore at Hunter College.
After water is drawn, it is filtered to concentrate the DNA for extraction. The target segment of the DNA is amplified in a laboratory and then sent for "next-generation" sequencing, the result of which--a record of all the DNA sequences in the sample--is fed into computer software that counts the number of copies of each sequence and searches for matches in an online public reference library.
The New Jersey study, co-authored by Mishu and bioinformatics expert Zachary Charlop-Powers, detected bony fish species in consistent seasonal patterns. And they found a small number of species accounted for the great majority of DNA obtained.
Detection of rays and other cartilaginous marine species, meanwhile, was confined mostly to warmer months.
In addition to straining its genetic material from the water, researchers used DNA to identify the decayed remains of a Brazilian cownose ray washed ashore in the sampling area in August 2017.
The researchers also added to growing global databases the first DNA reference sequences for 31 regional species catalogued by New Jersey scientists from trawl surveys over the past 30 years.
A growing number of applications emerging for aquatic environmental DNA (eDNA) tests: an innovative, inexpensive, low-impact way to monitor marine life migrations, changing ranges, diversity and distribution
Dr. Stoeckle's earlier studies of New York's East and Hudson Rivers revealed the presence or absence of several key fish species passing through those waters. The weekly data snapshots created a moving picture that largely reinforced and correlated with knowledge from years of fishnet trawls.
By conducting a series of tests over time, the work pioneered a novel way to record fish migration. eDNA has a goldilocks quality just right for research, Dr. Stoeckle notes: If it disappeared too quickly, sampling wouldn't tell us much; if it lingered too long, too much DNA would be in the water, undermining useful, timely insights.
Next steps include fine tuning calibrations, comparing eDNA "reads" and results with data from traditional surveys conducted with nets and sonar. Do 100 DNA "reads" indicate the presence of 1 fish or 10 fish?
Also to be determined: the rate at which different fish and other marine species shed DNA.
Support from the Marine Science and Policy Initiative of the Program for the Human Environment (The Rockefeller University) and the Urban Coast Institute (Monmouth University) initiated the work on aquatic DNA.
About Program for the Human Environment eDNA studies
Other images and tables used in the paper (https://bit.ly/2WD6OXE) are also available on request
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy
PRIVATE FOR PROFIT HEALTH CARE
Illuminating the impact of COVID-19 on hospitals and health systems in the USA
A comparative study of revenue and utilization
FAIR HEALTH
IMAGE: A FAIR HEALTH BRIEF, MAY 12, 2020. view more
CREDIT: WWW.FAIRHEALTH.ORG
NEW YORK, NY--May 12, 2020--In the third week of March 2020, as the COVID-19 pandemic escalated, large hospitals in the Northeast experienced a 26 percent decline in average per-facility revenues based on estimated in-network amounts as compared to the same period in 2019. Nationally, the decrease in revenue for large hospitals was 16 percent. These are among the findings of FAIR Health's second COVID-19 study, Illuminating the Impact of COVID-19 on Hospitals and Health Systems: A Comparative Study of Revenue and Utilization.
The third week of March 2020 was the week when thousands of new COVID-19 cases became commonplace in certain parts of the United States, particularly in the Northeast. Hospitals and health systems underwent financial strain as many elective procedures were deferred. FAIR Health's new brief illuminates the financial impact on hospitals by comparing revenues based on estimated in-network amounts on private insurance claims submitted by facilities in the first quarter (January to March) of 2020 with the first quarter of 2019 (adjusted by Consumer Price Index). The first quarter is analyzed month by month, and March is analyzed week by week. Also studied are discharge volume, settings, and diagnoses and procedures.
The study was based on claims data received by April 30, 2020, which meant some claims for services during the period examined were incurred but not reported (IBNR)--valid claims for covered services that had been performed but not yet reported to the insurer. For that reason, the 2019 claims used for the study were limited to those received by April 30, 2019, to produce an "apples to apples" comparison. Notwithstanding the IBNR issue, FAIR Health found that the impact of COVID-19 on hospitals was already substantial and of such public health relevance that it deemed it worthwhile to issue this report. FAIR Health will continue to monitor the data volume in the coming weeks.
Findings include:
In general, there was an association between larger hospital size and greater impact from COVID-19. Nationally, in large facilities (over 250 beds), average per-facility revenues based on estimated in-network amounts declined from $4.5 million in the first quarter of 2019 to $4.2 million in the first quarter of 2020. The gap was less pronounced in midsize facilities (101 to 250 beds) and not evident in small facilities (100 beds or fewer).
March was the month when COVID-19 had its greatest impact in the first quarter of 2020. Nationally, in that month, in midsize facilities, the decrease in average per-facility revenues based on estimated in-network amounts in 2020 from 2019 was four percent; in large facilities, five percent.
Facilities in the Northeast experienced a greater impact from COVID-19 than those in the nation as a whole. For example, in the Northeast, the decline in average per-facility revenues based on estimated in-network amounts in March 2020 from March 2019 was five percent for midsize facilities, nine percent for large ones.
Both nationally and in the Northeast, the decrease in facility discharge volume (i.e., patient discharges) from March 2019 to March 2020 was greater on a percentage basis than the decrease in revenues based on estimated in-network amounts. For example, in large facilities nationally, the drop in volume was 32 percent; in the Northeast, 40 percent.
Nationally, the decrease in facility discharge volume in the third week of March 2020 from the corresponding week in 2019 grew significantly compared to the first two weeks; it also appears greater than the decrease in the fourth week. But in the Northeast, in midsize facilities, the fourth week of March had a greater drop (34 percent) than the third week (30 percent).
From March 2019 to March 2020, the outpatient share of the distribution of estimated in-network amounts by settings decreased relative to the inpatient share. The effect was more pronounced in the Northeast than nationally.
The third and fourth weeks of March 2020, compared to the corresponding period in 2019, saw several changes in the most common diagnostic categories in the inpatient and ER settings. Nationally and in the Northeast, in the inpatient setting, diseases and disorders of the respiratory system rose in share of distribution by volume and estimated in-network dollars, while in the ER setting, acute respiratory diseases and infections rose.
FAIR Health President Robin Gelburd stated: "With this second study, we again use our data repository to shed light on the impact of COVID-19. As the pandemic continues to test the entire healthcare system, FAIR Health seeks to provide data and analysis to support all the system's participants."
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For the new FAIR Health brief on COVID-19, Illuminating the Impact of COVID-19 on Hospitals and Health Systems: A Comparative Study of Revenue and Utilization, click here.
For the first FAIR Health brief on COVID-19, COVID-19: The Projected Economic Impact of the COVID-19 Pandemic on the US Healthcare System, click here.
Follow us on Twitter @FAIRHealth
About FAIR Health
FAIR Health, a national, independent nonprofit organization that qualifies as a public charity under section 501(c)(3) of the tax code, is dedicated to bringing transparency to healthcare costs and health insurance information through data products, consumer resources and health systems research support. FAIR Health possesses the nation's largest collection of private healthcare claims data, which includes over 31 billion claim records contributed by payors and administrators who insure or process claims for private insurance plans covering more than 150 million individuals. FAIR Health licenses its privately billed data and data products--including benchmark modules, data visualizations, custom analytics and market indices--to commercial insurers and self-insurers, employers, providers, hospitals and healthcare systems, government agencies, researchers and others. Certified by the Centers for Medicare & Medicaid Services (CMS) as a national Qualified Entity, FAIR Health also receives data representing the experience of all individuals enrolled in traditional Medicare Parts A, B and D; FAIR Health houses data on Medicare Advantage enrollees in its private claims data repository. FAIR Health can produce insightful analytic reports and data products based on combined Medicare and commercial claims data for government, providers, payors and other authorized users. FAIR Health's systems for processing and storing protected health information have earned HITRUST CSF certification and achieved AICPA SOC 2 compliance by meeting the rigorous data security requirements of these standards. As a testament to the reliability and objectivity of FAIR Health data, the data have been incorporated in statutes and regulations around the country and designated as the official, neutral data source for a variety of state health programs, including workers' compensation and personal injury protection (PIP) programs. FAIR Health data serve as an official reference point in support of certain state balance billing laws that protect consumers against bills for surprise out-of-network and emergency services. FAIR Health also uses its database to power a free consumer website available in English and Spanish and an English/Spanish mobile app, which enable consumers to estimate and plan for their healthcare expenditures and offer a rich educational platform on health insurance. The website has been honored by the White House Summit on Smart Disclosure, the Agency for Healthcare Research and Quality (AHRQ), URAC, the eHealthcare Leadership Awards, appPicker, Employee Benefit News and Kiplinger's Personal Finance. FAIR Health also is named a top resource for patients in Dr. Marty Makary's book The Price We Pay: What Broke American Health Care--and How to Fix It and Elisabeth Rosenthal's book An American Sickness: How Healthcare Became Big Business and How You Can Take It Back. For more information on FAIR Health, visit fairhealth.org.
Are more head impacts during NFL career associated with increased risk of death?
JAMA NETWORK OPEN
What The Study Did: Nearly 14,000 current and former National Football League (NFL) players were included in an observational study that examined whether a greater amount of repeated head impacts throughout a professional football career were associated with increased risk of death.
Authors: Brittany L. Kmush, Ph.D., of Syracuse University in Syracuse, New York, is the corresponding author.
Editor's Note: The article includes funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.
Media advisory: The full study is linked to this news release.
Embed this link to provide your readers free access to the full-text article
About JAMA Network Open: JAMA Network Open is the new online-only open access general medical journal from the JAMA Network. On weekdays, the journal publishes peer-reviewed clinical research and commentary in more than 40 medical and health subject areas. Every article is free online from the day of publication.
A tale of two kinds of volcanoes
UNIVERSITY OF JOHANNESBURG
IMAGE: WHY A BIG VOLCANIC BLOW-UP AT THE POPULAR TRAVEL DESTIMATION SANTORINI 3200 YEARS AGO, BUT JUST A FEW HUNDRED KILOMETERS AWAY, NO DRAMA AT THE VOLCANOES ON AEGINA , METHANA... view more
CREDIT: MS THERESE VAN WYK, UNIVERSITY OF JOHANNESBURG
At an idyllic island in the Mediterranean Sea, ocean covers up the site of a vast volcanic explosion from 3200 years ago. A few hundred kilometers north-west, three other islands still have their volcanic histories from a few million years ago mostly intact. No explosions there. So why the differences between the Santorini caldera and the Aegina, Methana and Poros lava domes? Researchers used volcanic "fingerprints' and plate tectonics research to find out why.
The end of a civilisation
A big volcano blew up about 3200 years ago, right next to where Santorini island is in Greece today. During that eruption, liquid molten rock under the ground (magma) built up immense pressure, and then erupted into a lava explosion. The impact was so intense that the volcano collapsed into a huge basin called a caldera.
What had been an island-volcano, was then overrun by ocean, an event considered partially responsible for the demise of the Minoan civilisation.
Santorini Island became a popular travel destination with big ocean-going ships sailing over the caldera. The village of Phira perches on the cliff-edge of the remains of the volcano.
As idyllic as it looks, the Santorini volcano underneath the ocean still constitutes the biggest volcanic hazard for Europe, together with the Vesuvius volcano in Italy.
Toothpaste rather than fireworks
A few hundred kilometers north-west of Santorini, in Greece's Saronic gulf much closer to Athens, a completely different kind of "volcano" looks much less dramatic.
The small islands of Aegina, Methana and Poros sport rounded hills with roads winding uphill in hairpin bends. These hills have volcanic ancestry too - but they are nothing like Santorini.
Here, liquid lava didn't explode in a big eruption.
"There is no evidence that that large dramatic events ever took place at these islands," says Prof Marlina A. Elburg, a Geology researcher at the University of Johannesburg.
"Thick blocky lava oozed out of magma chambers under the ground at these islands between 5.3 to 2.6 million years ago, during the Pliocene. The lava was so thick, it was more like toothpaste or putty than liquid. It formed lava domes rather than lava volcanoes.
"After a few million years' worth of weathering, they're well camouflaged hills, but they are still considered volcanically active," she says.
How is it possible that volcanoes so close in geological time and space can behave to differently? The researchers used several techniques to find out.
Why a big volcanic blow-up at the popular travel destimation Santorini 3200 years ago, but just a few hundred kilometers away, no drama at the volcanoes on Aegina , Methana and Poros islands? Thin sections of the lavas from these four volcanoes yield some of the reasons why. Some minerals only form at greater depths - and the hornblende in the lava from Aegina island indicates that the magma chambers there are deeper than the those underneath the Santorini caldera. But plate tectonics add another, hidden reason also, found research from the University of Johannesburg.
Finding volcanic 'fingerprints'
Elburg and co-author Ingrid Smet, a PhD candidate at the time, analysed samples of the lavas in new whole rock analyses, in research published in Lithos.
The study followed on their previous research on the lavas at Methana, also published in Lithos.
They looked for the ratios of very specific elements in the samples, called isotope signatures. Isotope signatures work similar to 'fingerprints' for lavas - they help researchers figure out what the lavas were made of, where, and when they were formed.
"Mostly the isotope signatures matched what one would expect from where the islands are located in the Aegean volcanic arc," says Elburg.
But there were surprises too.
Subterranean recycling machine
Underneath all these volcanoes at Aegina, Methana, Poros and Santorini, something else is going on in deep inside the crust of planet Earth. Running roughly east to west underneath the Mediterranean Sea is the Aegean volcanic arc. This arc is where the African tectonic plate 'dives under' the Aegean microplate.
The 'diving under' process is called subduction by geologists. It means that one part of the cool outer crust of Earth starts moving underneath another part of the crust, getting 'recycled' inside the hot liquid rock of the Earth's mantle.
The islands of Aegina, Methana, Poros and Santorini are not just islands with volcanoes. All of them are an integral part of Earth's 'recycling machine' that keeps renewing the crust underneath the planet's oceans.
This raises the question: Why do these islands have such different 'lava histories', even though all of them are on the edge of the Aegean plate?
Some of the answers have to do with what goes into the lava "mixes" for the volcanoes.
Why a big volcanic blow-up at the popular travel destimation Santorini 3200 years ago, but just a few hundred kilometers away, no drama at the volcanoes on Aegina , Methana and Poros islands? At Santorini, the explosion was so intense, the volcano collapsed into a caldera and filled up with ocean. But the other islands have had no such drama. How can volcanoes so close in geological time and space behave so differently? Research from the University of Johannesburg uses lava 'fingerprints' and more to find out why.
Variable lava mix recipes
The African plate 'dives under' the Aegean plate in an oceanic trench in the Mediterranean Sea. This happens very slowly at a few centimeters per year. Which means the pristine cold basalt of the down-going African plate's crust has been soaking in ocean water for millions of years before it enters the much warmer magma underneath the over-riding Aegean plate.
"The crust of the down-going plate now consists of altered rocks, containing minerals with water in them. These minerals become unstable during subduction because of the increasing pressure and temperature, and release their water," says Elburg.
"This water lowers the melting point of the mantle, similar to what happens when adding salt to ice. That is why the mantle under the over-riding starts to melt. It is this molten material, or magma, that flows/oozes out of volcanoes/lava domes as lava."
Another possible ingredient of the differing lavas is sediments in the oceanic trench at the subduction zone. At the Aegean Arc the down-going plate is covered by a very thick pile of ocean sediments. Some of the sediment is former continental crust.
A lot of this sediment is 'scraped off' when the plate subducts and forms an accretionary (or build-up) wedge. However, some of it is also going down into the mantle and getting mixed with the melting mantle wedge, she says.
Same plate, different lavas
Since Aegina, Methana, Poros and Santorini volcanoes are all part of the same subduction zone, the different volcanic activity raises several big questions. One of these is:
Why the thick blocky lava at the western volcanic centres Aegina, Methana and Poros 2.5 to 2 million years ago, but liquid lava at Santorini 3200 years ago?
The answers to this creates other questions about the recycling behaviour of the planet we live on.
But subduction zones are tricky to study. It's not possible to go to one of those and come back with some sample materials. Scientists still need more understanding of what role the overriding plate plays; how much interaction there is between ascending magmas and the crust they ascend through; and whether subduction-related magmas obtain their geochemical signature from the sediment that is recycled back into the earth, says Elburg.
"The answers to these questions can help us understand to what extent the melting processes that started at more than 100 kilometers deep in the mantle, continue when the magma is closer to the surface of the earth," she says.
"This process of 'crustal contamination' is yet another 'Earth recycling machine', which may also influence the potential for ore deposits - like in the Andes, where major copper deposits are found, and where this 'intracrustal recycling' is thought to play an important role".
Deeper vs shallower
One way of studying lavas is to put thin slices (called thin sections) under a microscope and identify the minerals. Because minerals need different conditions to form, their presence can say a lot about where and how magmas were mixed.
In this study the minerals indicated that Santorini lavas were more liquid because they formed at inside shallower magma chambers, while the western volcanic centre lavas were thicker and more blocky because they formed in deeper magma chambers.
"The thin sections of the Santorini lavas display pyroxenes and significant plagioclase. This indicates that the magma from which the crystals formed was located at shallow depths in the earth," says Elburg.
And there is an invisible reason the magma was at shallower depths at Santorini.
"The tectonic plate above Santorini's magma chambers is being pulled apart. In geology terms, it is under localised extension. And because the plate is being stretched out and Santorini is in the middle of it, Santorini happens to be at the thinnest part of the plate.
"With a magma chamber at a shallower depth, the roof will cave in when the chamber starts emptying itself during an eruption. This makes the eruption even worse and creates a caldera, as at Santorini," she adds.
No explosions
In contrast, when they looked at the thin sections of the thick blocky lavas from Aegina and Methana, they found hornblende. The mineral was absent in the Santorini lavas.
Hornblende can only form if the magma is deep enough in the Earth. This indicates that the magma chambers on Aegina and Methana should be located deeper than on Santorini.
"With the magma chambers at greater depths for the western Aegina- Methana-Poros volcanoes, that makes for changes in the lava. There the magma chambers underneath the lava domes did not cave in. Additionally, the crystallization of the amphibole mineral group that includes hornblende, makes magma more viscous, or sticky. So it is more difficult for the magma to come to the surface in the first place.
Over-riding plate vs sediment
To figure out whether the over-riding plate or the ocean sediments were the bigger factor in creating thick blocky lavas, the researchers analysed specific 'lava fingerprints'. These radiogenic isotope ratios gave them the best indication on which materials were mixed into the underground magmas for those lavas.
"We compared Santorini with Aegina-Poros-Methana lavas in terms of their geochemistry on 87Sr/86Sr, 143Nd/144Nd and 208Pb/204Pb. They were distinctly different. Then by combining the radiogenic isotope signature of the lavas with trace element ratios, we managed to pinpoint the down-going sediment as the biggest influence creating thick blocky lavas, not the overriding plate.
No one lava size
"We found that Aegina and Methana-Poros have their own individual volcanic histories, even though they're part of the Aegean arc.
"This means that a simple one-size-fits-all explanation, based on crustal contamination history, for the difference in eruptive style compared to Santorini does not work.
"Modern subduction zones are not all alike. Even in one volcanic arc, more than one eruptive style points to differences in subduction processes," concludes Elburg.
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INTERVIEWS: For email interviews or questions, contact Prof Elburg at @uj.ac.za.
For interviews via mobile phone / Skype / Zoom with Prof Elburg, contact Ms Therese van Wyk at Theresevw@uj.ac.za or +27 71 139 8407 (mobile) in Johannesburg, UTC + 2.
The research was funded by FWO grants G.0585.06N, G.0669.06 and 1509007N., and TransNational Access project 079-TNA3 of Europlanet.
Chemical evidence of dairying by hunter-gatherers in Lesotho in the first millennium AD
UNIVERSITY OF BRISTOL
IMAGE: VIEW FROM JUST NORTH OF LIKOAENG (SITE LOCATION INDICATED WITH AN ARROW), LOOKING DOWNSTREAM ALONG THE SENQU RIVER. THE LINE OF CLIFFS RUNNING MIDWAY THROUGH THE PHOTO FROM THE LEFT... view more
CREDIT: PETER J. MITCHELL
After analysing organic residues from ancient pots, a team of scientists led by the University of Bristol has uncovered new evidence of dairying by hunter-gatherers in the landlocked South African country of Lesotho in the mid-late first millennium AD.
The study on organic residue analysis from South African hunter-gatherer pots is being published today in Nature Human Behaviour. Extensive archaeological evidence shows that Early Iron Age agricultural communities settled in the coastal regions of KwaZulu-Natal in South Africa from around AD 400.
Although these farmers appear to have been in contact with local lowland hunter-gatherer groups, it was long assumed that they had little or no direct contact with hunter-gatherers already occupying the mountainous regions of Lesotho, as they did not settle the region until the 19th century due to the unsuitability of the mountains for crop cultivation.
Over the past several decades however, remains of domestic animal bones have been uncovered in several sites in the Maloti-Drakensberg Mountains in Lesotho in hunter-gatherer contexts dating to the 1st and 2nd millennia AD.
At one site in particular - Likoaeng - domestic animal bones were found in association with an Early Iron Age potsherd and some fragments of iron. This discovery led to the suggestion that the hunter-gatherers occupying the site were following a 'hunters-with-sheep' mode of subsistence that incorporated the keeping of small numbers of livestock into what was otherwise a foraging economy and that they must have obtained these animals and objects through on-going contact with agricultural groups based on the coast.
In the past five years however, several studies have sequenced DNA from supposed domestic animal bones from these highland sites, and instead found them to belong to wild species. This led to the suggestion that the presence of domestic animals in the highlands, and therefore the level of contact, had been overestimated, yet the zooarchaeologists involved stand by their original morphological assessment of the bones.
Lead researcher, Helen Fewlass, now based at the Max Planck Institute for Evolutionary Anthropology (Leipzig) but who carried out the work as part of her master's project in the University of Bristol's Department of Anthropology and Archaeology, said: "We used organic residue analysis to investigate fats that become absorbed into the porous clay matrix of a pot during its use.
"We extracted and analysed lipid residues from pots from two hunter-gatherer sites with domestic livestock remains in the highlands of Lesotho, Likoaeng and Sehonghong, dating to the mid-late first millennium AD and compared them to lipids extracted from pots from a recent nearby agricultural settlement, Mokatlapoli.
"This allowed us to explore the subsistence practices of the hunter-gatherers occupying these sites to see if there was any evidence for their contact with farming groups."
The team found that dairy residues were present in approximately a third of the hunter-gatherer pots. They directly radiocarbon dated a dairy residue from Likoaeng to AD 579-654 and another from Sehonghong to AD 885-990. The results confirm the presence of domestic animals at these sites in the 1st millennium AD.
The team also observed patterning in the stable carbon isotopic values of fatty acids in the residues, which imply that different methods of animal husbandry were practised by the 1st millennium hunter-gatherer groups compared to the recent agricultural group occupying the same region.
The stable carbon isotopic values of dairy residues from the agricultural site clearly reflect the introduction of crops such as maize and sorghum into the region in the late nineteenth century and the foddering of domestic animals upon them.
As the hunter-gatherer groups must have learnt animal husbandry techniques, the results support the notion that hunter-gatherer groups in the highlands of Lesotho had on-going contact with farming communities in the lowlands, rather than just obtaining the animals through raids or long-distance exchange networks. Based on the direct date of the dairy residue from Likoaeng, contact must have been established within a few centuries of the arrival of agricultural groups in the coastal regions of South Africa.
The results also have implications for the on-going debate about the molecular vs morphological assessment of the faunal remains. The results of the organic residue analysis support the osteoarchaeological evidence for the presence of domestic animals at Likoaeng and Sehonghong. However, as large amounts of milk can be generated from one domestic animal, the prevalence of dairy residues does not tell us how many domestic animals were present.
Direct radiocarbon dating of domestic faunal remains in these contexts has been hampered by poor collagen preservation. The new method (published earlier this month in Nature) for direct dating of fats extracted from potsherds represents a new avenue for placing the arrival and presence of domestic animals in the area in a secure chronological context.
Helen Fewlass added: "The presence of dairy fats in pots from Likoaeng and Sehonghong in highland Lesotho shows that hunter-gatherers in the mountains had adopted at least sporadic use of livestock from agricultural groups in South Africa not long after their arrival in the 1st millennium AD."
Co-author, Dr Emmanuelle Casanova, from the University of Bristol's Organic Geochemistry Unit - part of the School of Chemistry, added: "In addition to the identification of dairying practices we were able apply a brand-new dating method for pottery vessels to verify the antiquity of the dairy residues which perfectly fits with the age of the hunter-gatherer groups."
This study represents the first analysis and direct radiocarbon dating of organic residues from pottery from south-eastern Africa. The high level of preservation found implies that the method has great potential for further applications in the region. This mountainous area of Lesotho has other hunter-gatherer sites containing pottery in contexts dating to the 1st and 2nd millennium AD so there is potential to expand this type of analysis to other sites in the region to understand whether this practise was relatively isolated or ubiquitous.
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New research determines our species created earliest modern artifacts in Europe
Innovative tools and pendants previously thought to be possibly the work of Neanderthals
NEW YORK UNIVERSITY
IMAGE: STONE ARTIFACTS FROM THE INITIAL UPPER PALEOLITHIC AT BACHO KIRO CAVE. 1-3, 5-7: POINTED BLADES AND FRAGMENTS FROM LAYER I; 4: SANDSTONE BEAD WITH MORPHOLOGY SIMILAR TO BONE BEADS; 8:... view more
Blade-like tools and animal tooth pendants previously discovered in Europe, and once thought to possibly be the work of Neanderthals, are in fact the creation of Homo sapiens, or modern humans, who emigrated from Africa, finds a new analysis by an international team of researchers.
Its conclusions, reported in the journal Nature, add new clarity to the arrival of Homo sapiens into Europe and to their interactions with the continent's indigenous and declining Neanderthal population.
The analysis centers on an earlier discovery of bones and other artifacts found in the Bacho Kiro cave in what is modern-day Bulgaria.
"Our findings link the expansion of what were then advanced technologies, such as blade tools and pendants made from teeth and bone, with the spread of Homo sapiens more than 45,000 years ago," explains Shara Bailey, a professor in NYU's Department of Anthropology and one of the paper's co-authors. "This confirms that Homo sapiens were mostly responsible for these 'modern' creations and that similarities between these and other sites in which Neanderthals made similar things are due to interaction between the populations."
The findings offer a new understanding of both the nature of these species and their interactions.
"If Neanderthals had created these 'modern' tools and jewelry, it would have indicated they had more advanced cognitive abilities than previously recognized," explains Bailey. "Nonetheless, there are some similarities in manufacturing techniques used by Homo sapiens at Bacho Kiro and Neanderthals elsewhere, which makes clear that there was cultural transmission going on between the two groups."
The analysis was led by researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
The team, which included scientists from Europe, the United States, and the United Kingdom, focused on the transition from the Middle to Upper Palaeolithic period, between 50,000 and 30,000 years ago. During this time, the European continent experienced the replacement and partial absorption of local Neanderthals by Homo sapiens populations from Africa. However, this process, anthropologists say, likely varied across regions, and the details of this transition remain largely unknown.
To better comprehend a piece of this transition, the team focused on one of several places--Bacho Kiro--where discoveries of the earliest modern technologies, such as pendants and blades, have been made.
To ascertain which species occupied the area of these discoveries, the scientists deployed several methodologies. Bailey, an expert in tooth analysis, and her colleagues examined teeth and bones that had been found in Bacho Kiro.
Using state-of-the-art technology called ZooMS (collagen peptide mass fingerprinting), they identified human bone fragments and concluded that they were at least 45,000 years old--a period coinciding with the arrival of multiple waves of Homo sapiens into Europe. Subsequent shape analyses of the tooth and DNA examination of the fragments determined that they belonged to Homo sapiens and not Neanderthals, whose presence was not evident among the discovered fossils.
"ZooMS allows us to identify previously unidentifiable bone fragments as some form of human," explains Bailey. "From there, we can apply more sophisticated techniques to identify the species and more accurately date human bones."
