четверг, 6 декабря 2018 г.

Ariane 6 on the way to flight


ESA – European Space Agency patch (old).


6 December 2018


This has been an intense year for Ariane 6 development, with progress boosted across Europe: plants are manufacturing new parts using novel methods, all engines have been tested, and the construction of launch facilities is well underway.



Artist’s view of the configuration of Ariane 6 using four boosters (A64)

ESA has worked with an industrial network led by prime contractor ArianeGroup, of more than 600 companies in 13 European countries, including 350 small- and medium-sized enterprises, to fine-tune the design and start production. Meanwhile, France’s CNES space agency has been preparing its launch facilities at Europe’s Spaceport in French Guiana.


Details on all these activities were recently shared at the 69th International Astronautical Congress in Bremen, Germany – along with two papers submitted to the congress: launch system and launcher system, here are the highlights:


https://esamultimedia.esa.int/docs/STS/Ariane6_Presentation2018.pdf


https://esamultimedia.esa.int/docs/STS/IAC-18,D2,1,1,x48586.pdf


https://esamultimedia.esa.int/docs/STS/IAC-18,D2,1,2,x42969.pdf


Europe’s launcher for a new decade



Ariane 6 possible missions and configurations

Europe’s new Ariane 6 launcher covers a broad range of commercial and institutional applications while dramatically decreasing the cost of launches compared to Ariane 5.


Enabled by ESA’s Light satellite Low-cost Launch opportunity Initiative, a multiple launch service for small satellites starting mid-2021 will offer cost-effective launch opportunities for satellites of under 400 kg, via a rideshare approach on launchers such as Ariane 6, and its smaller cousin Vega-C.


The Ariane 6’s core stage is powered by Vulcain 2.1, an upgraded engine derived from Ariane 5’s Vulcain 2; its upper stage is powered by the reignitable Vinci engine. Two or four P120C solid-fuel boosters for Ariane 6, common with Vega-C, will be strapped on to provide thrust at liftoff.


The P120C and Vulcain 2.1 development models have started their ground testing, the Vinci is now qualified. This leads to the next significant milestone: the delivery of the Ariane 6 qualification model, to start combined tests in French Guiana at the end of 2019.


The second P120C model will be tested in French Guiana early next year, to verify its design and performance.


The Ariane 6 upper stage will be tested at the DLR German Aerospace Center newly developed P5.2 test facility in Lampoldshausen at the end of 2019.


Specialist factories have started production


Casings for the P120C boosters are formed from specially developed carbon composite fibre, which is wound at Avio’s Colleferro factory in Italy.


The nozzles for the boosters will be produced at a rate of 35 per year from a highly automated facility opened in July in Le-Haillan, France.



Tour Avio’s Colleferro factory

This April, MT-Aerospace – one of the main industrial partners of ArianeGroup on the Ariane 6 project – integrated the first hydrogen tanks of Ariane 6’s upper stage liquid propulsion module at their Bremen, Germany, facility.


Airbus Defence and Space opened a facility this month in Oegstgeest, the Netherlands, to develop, build, test and qualify the engine frames for the Vulcain and Vinci engines. The Vinci frame will be transported to Bremen. The Vulcain frame will be sent to Les Mureaux, France, for final assembly with the Ariane 6 core stage.



Hydrogen tank for Ariane 6 upper stage

By the end of this year the ArianeGroup facility in Les Mureaux – hosting the largest friction stir welding machines in Europe – will be poised to begin producing the Ariane 6 cryogenic tanks at a rate of seven to eight stages at a time for Ariane 6’s lower liquid propulsion module.


Testing the limits of Ariane 6 propulsion


Testing is about stretching the limits of performance to gain a detailed understanding of how components work, not just under normal operating conditions but also at higher temperatures, pressures, and with different fuel mixtures.


The P120C booster underwent hot firing at Europe’s spaceport in French Guiana in July 2018. In 135 seconds it burned 142 tonnes of propellant.



First hot firing of P120C motor for Vega-C and Ariane 6

The Vulcain 2.1 engine will help to propel Ariane 6 in the first 10 minutes of flight, up to an altitude of 200 km, delivering 135 tonnes of thrust in vacuum. It has a simplified and more robust nozzle, a 3D-printed gas generator, and a heater for oxygen tank pressurisation.



Vulcain 2.1 engine first hot firing

The test campaign started in January with the first test firing at the DLR German Aerospace Center test facilities in Lampoldshausen. A total of 11 successful subsequent tests of the engine brought its total accumulated burn time to over 105 minutes. The second test campaign began in October.


Vinci is the re-ignitable engine of the upper stage that increases the operational flexibility of Ariane 6 and ensures that the engine safely deorbits at the end of the mission.



Vinci engine qualified in tests

This engine was successfully tested more than 140 times and reignited multiple times in succession in near vacuum to complete its qualification. Final testing in October brought a total of more than 14 hours of operation.


Launch facilities taking shape at Europe’s Spaceport
 



Timelapse chantier Ariane 6

About 600 people are currently employed in the construction of the Ariane 6 launch pad, which is 28.5 metres deep and 200 metres wide, formed with enough concrete to fill 67 Olympic sized swimming pools – approximately 167,500 cubic m.


In September, the 700 tonne launch table that will support Ariane 6 at launch was positioned on the launch pad.


The 8200 tonne mobile gantry that will store and protect Ariane 6 until it is retracted five hours before each launch, is currently being erected.


The steel deflectors that will funnel the fiery plumes of Ariane 6 into the exhaust tunnels at liftoff will soon be installed at the base of the launch pad.


Related articles & link:


Ariane 6 launch-pad: http://blogs.esa.int/ariane6/2018/06/01/deflecting-the-fiery-plumes-of-ariane-6/


ESA’s Light satellite Low-cost Launch opportunity Initiative: http://www.esa.int/Our_Activities/Space_Transportation/Shared_launch_opportunities_for_light_satellites


69th International Astronautical Congress in Bremen, Germany: http://www.iafastro.org/


Related links:


Airbus Defence and Space: http://www.airbus.com/space.html


ArianeGroup: https://www.ariane.group/en/


Avio: http://www.avio.com/en/


CNES: https://cnes.fr/en


MT Aerospace: http://www.mt-aerospace.de/


Space Transportation: http://www.esa.int/Our_Activities/Space_Transportation


Images, Videos, Text, Credits: ESA/D. Ducros/ArianeGroup/Holding-Hill Media/Euronews.


Best regards, Orbiter.chArchive link


Tracing iron in the North Pacific…


Tracing iron in the North Pacific http://www.geologypage.com/2018/12/tracing-iron-in-the-north-pacific.html


A microbe’s membrane helps it survive extreme environments…


A microbe’s membrane helps it survive extreme environments http://www.geologypage.com/2018/12/a-microbes-membrane-helps-it-survive-extreme-environments.html


Volcanoes fed by ‘mush’ reservoirs rather than molten magma…


Volcanoes fed by ‘mush’ reservoirs rather than molten magma chambers http://www.geologypage.com/2018/12/volcanoes-fed-by-mush-reservoirs-rather-than-molten-magma-chambers.html


Soft tissue shows Jurassic ichthyosaur was warm-blooded, had…


Soft tissue shows Jurassic ichthyosaur was warm-blooded, had blubber and camouflage http://www.geologypage.com/2018/12/soft-tissue-shows-jurassic-ichthyosaur-was-warm-blooded-had-blubber-and-camouflage.html


Human Research, Robotic Refueling, Crystallography and More Headed to Orbiting Lab

New

science is headed to the International Space Station aboard

the SpaceX Dragon.


Investigations

on this flight include a test of robotic technology for refueling spacecraft, a

project to map the world’s forests and two student studies inspired by Marvel’s

“Guardians of the Galaxy” series.


Learn

more about the science heading into low-Earth orbit:


The

forest is strong with this one: GEDI studies Earth’s forests in 3D


The Global Ecosystem

Dynamics Investigation (GEDI) is an instrument to measure and map Earth’s

tropical and temperate forests in 3D.


image

The Jedi knights may help

protect a galaxy far, far away, but our GEDI

will help us study and understand forest changes right here on Earth.


Robotic

refueling in space


What’s cooler than cool? Cryogenic propellants,

or ice-cold spacecraft fuel! Our Robotic Refueling Mission 3 (RRM3) will demonstrate technologies for storing and

transferring these special liquids. By establishing ways to replenish this fuel

supply in space, RRM3 could help spacecraft live

longer and journey farther
.


image

The mission’s techniques could even be applied

to potential lunar gas stations at the Moon, or refueling

rockets departing from Mars.


Staying

strong in space


The

Molecular Muscle investigation examines the

molecular causes of muscle abnormalities from spaceflight in C. elgans, a

roundworm and model organism.


This

study could give researchers a better understanding of why muscles deteriorate

in microgravity so they can improve methods to help crew members maintain their

strength in space.


image

Investigation

studies space-grown crystals for protection against radiation


Perfect Crystals is a study to learn more about an

antioxidant protein called manganese superoxide dismutase that protects the

body from the effects of radiation and some harmful chemicals.


The

station’s microgravity environment allows researchers to grow more perfectly

ordered crystals of the proteins. These crystals are brought back to Earth and

studied in detail to learn more about how the manganese superoxide dismutase

works. Understanding how this protein functions may aid researchers in

developing techniques to reduce the threat of radiation exposure to astronauts

as well as prevent and treat some kinds of cancers on Earth.


Satellite

deployment reaching new heights with SlingShot


SlingShot

is a new, cost-effective commercial satellite deployment system that will be

tested for the first time.


image

SlingShot

hardware, two small CubeSats, and a hosted payload will be carried to the

station inside SpaceX’s Dragon capsule and installed on a Cygnus spacecraft

already docked to the orbiting laboratory. Later, Cygnus will depart station

and fly to a pre-determined altitude to release the satellites and interact

with the hosted payload.


Investigation

studies accelerated aging in microgravity


Spaceflight

appears to accelerate aging in both humans and mice. Rodent Research-8 (RR-8) is a study to understand the physiology of

aging and the role it plays on the progression of disease in humans. This

investigation could provide a better understanding of how aging changes the

body, which may lead to new therapies for related conditions experienced by

astronauts in space and people on Earth.


Guardians

of the space station: Student contest flies to orbiting lab


The

MARVEL ‘Guardians of the Galaxy’ Space Station Challenge is a joint project between

the U.S. National Laboratory and Marvel Entertainment featuring two winning

experiments from a contest for American teenage students. For the contest,

students were asked to submit microgravity experiment concepts that related to

the Rocket and Groot characters from Marvel’s “Guardians of the Galaxy” comic

book series.


image

Team

Rocket: Staying Healthy in Space


If

an astronaut suffers a broken tooth or lost filling in space, they need a

reliable and easy way to fix it. This experiment investigates how well a dental

glue activated by ultraviolet light would work in microgravity. Researchers

will evaluate the use of the glue by treating simulated broken teeth and

testing them aboard the station.


Team

Groot: Aeroponic Farming in Microgravity


This

experiment explores an alternative method for watering plants in the absence of

gravity using a misting device to deliver water to the plant roots and an air

pump to blow excess water away. Results from this experiment may enable humans

to grow fruits and vegetables in microgravity, and eliminate a major obstacle

for long-term spaceflight.


These

investigation join hundreds of others currently happening aboard the station.

For more info, follow @ISS_Research!



Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com 


HiPOD (5 December 2018): Layers in a Crater Near Phlegra Montes …



HiPOD (5 December 2018): Layers in a Crater Near Phlegra Montes


   – The objective of this observation is to examine layers near the top of a crater. (Alt: 288 km. Black and white is less than 5 km across; enhanced color is less than 1 km across.)


NASA/JPL/University of Arizona


2018 December 6 Cetus Galaxies and Supernova Image Credit…


2018 December 6


Cetus Galaxies and Supernova
Image Credit & Copyright: Massimiliano Veschini


Explanation: Large spiral galaxy NGC 1055 at top left joins spiral Messier 77 (bottom right) in this cosmic view toward the aquatic constellation Cetus. The narrowed, dusty appearance of edge-on spiral NGC 1055 contrasts nicely with the face-on view of M77’s bright nucleus and spiral arms. Both over 100,000 light-years across, the pair are dominant members of a small galaxy group about 60 million light-years away. At that estimated distance, M77 is one of the most remote objects in Charles Messier’s catalog, and is separated from fellow island universe NGC 1055 by at least 500,000 light-years. The field of view is about the size of the full Moon on the sky and includes colorful foreground Milky Way stars along with more distant background galaxies. Taken on November 28, the sharp image also includes newly discovered supernova SN2018ivc, its location indicated in the arms of M77. The light from the explosion of one of M77’s massive stars was discovered by telescopes on planet Earth only a few days earlier on November 24.


∞ Source: apod.nasa.gov/apod/ap181206.html


Uneven rates of sea level rise tied to climate change

The pattern of uneven sea level rise over the last quarter century has been driven in part by human-caused climate change, not just natural variability, according to a new study.











Uneven rates of sea level rise tied to climate change
Altimeter era sea level trends [Credit: John T. Fasullo]

The findings suggest that regions of the world where seas have risen at higher than average rates — including the Eastern Seaboard of the United States and the Gulf of Mexico — can expect the trend to continue as the climate warms.


The study, published today in the Proceedings of the National Academy of Sciences, was authored by scientists John Fasullo at the National Center for Atmospheric Research (NCAR) and Steve Nerem at the University of Colorado Boulder.


“By knowing that climate change is playing a role in creating these regional patterns, we can be more confident that these same patterns may linger or even intensify in the future if climate change continues unabated,” Fasullo said. “With sea levels projected to rise a couple of feet or more this century on average, information about expected regional differences could be critical for coastal communities as they prepare.”


The research was funded by the National Science Foundation, which is NCAR’s sponsor, the NASA Sea Level Change Team, and the U.S. Department of Energy.


Finding the signal of climate change


For the study, Fasullo and Nerem, both members of the NASA Sea Level Change Team, analyzed the satellite altimetry sea level record, which includes measurements of sea surface heights stretching back to 1993. They mapped global average sea level rise as well as how particular regions deviated from the average.


For example, the oceans surrounding Antarctica and the U.S. West Coast have had lower-than-average sea level rise, while the U.S. East Coast and Southeast Asia, including the Philippines and Indonesia, have experienced the opposite. In some parts of the world, the rate of local sea level rise has been as much as twice the average.


Regional differences in sea level rise are influenced by where heat is stored in the ocean (since warm water expands to fill more space than cold water) and how that heat is transported around the globe by currents and wind. Uneven sea level rise is also influenced by ice sheets, which lose mass as they melt and shift the gravitational forces affecting regional sea surface height.


Natural shifts in ocean cycles — including the Pacific Decadal Oscillation, a pattern of sea surface temperatures similar to El Niño but longer lasting — are therefore known to affect sea levels. So scientists were not surprised to find that as the ocean rises, it rises unevenly. But it’s been difficult to say whether these natural cycles were the dominant influence on regional differences.


To investigate the role of climate change, the scientists turned to two sets of climate model runs, known as “large ensembles”: one created using the NCAR-based Community Earth System Model and one created using the Earth System Model at the National Oceanic and Atmospheric Administration. These large ensembles — many model simulations by the same model, describing the same time period — allow researchers to disentangle natural variability from the impacts of climate change. With enough runs, these impacts can be isolated even when they are relatively small compared to the impacts from natural variability.


The climate models suggest that in regions that have seen more or less sea level rise than average, as much as half of that variation may be attributed to climate change. The scientists also found that the impacts from climate change on regional sea level rise sometimes mimic the impacts from natural cycles.


“It turns out the sea level rise response to climate change in the Pacific resembles what happens during a particular phase of the Pacific Decadal Oscillation,” Fasullo said. “This explains why it’s been so difficult to determine how much of the pattern was natural or not, until now.”


Improving forecasts


The research findings have implications for local officials, who are interested in improved forecasts of sea level rise for the areas they oversee. In the past, forecasters have had to rely on the global rate of change — about 3 millimeters a year and accelerating — and knowledge of the uneven regional impacts associated with continued melting of the ice sheets covering Greenland and Antarctica.


The findings add the possibility that the regional patterns of sea level rise tied to climate change can also be included, because the models predict that the regional patterns observed in the satellite measurements will continue into the future.


“We now have a new tool — long-term satellite altimeter measurements — that we can use to help stakeholders who need information for specific locations,” said Nerem, a fellow of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder and a professor of aerospace engineering.


Author: Laura Snider | Source: National Center for Atmospheric Research [December 03, 2018]



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Darwin’s finches have developed a taste for junk food, and it may be impacting...

A UMass Boston professor and his colleagues have published new research showing that feeding on human junk food may be altering the course of evolution in Darwin’s finches.











Darwin's finches have developed a taste for junk food, and it may be impacting their evolution
Finches eat off a plate in an urban area of the Galapagos
[Credit: K. Gotanda]

Assistant Professor of Evolutionary Biology Luis De León says feeding on human foods is weakening natural selection on ground finch beaks, which is what drives the formation of new species in the wild. These findings, published in the journal Evolutionary Applications, suggest that the seemingly harmless activity of feeding birds might be altering the course of evolution in the iconic Darwin’s finches in the Galápagos islands.


“If we continue to feed finches, we’re not only affecting the individual species, but the processes that lead to the formation of new species,” De León said. “We’re getting in the way of evolution.”


Galápagos finches are famed for being the inspiration behind Charles Darwin’s pioneering work on evolution. They are an example of adaptive radiation, an evolutionary process that produces new species from a single, rapidly diversifying lineage. Their common ancestor arrived on the Galápagos about two million years ago, and since then Darwin’s finches have evolved into more than a dozen recognized species differing in body size, beak shape, and feeding behavior.


De León and fellow researchers from UMass Amherst, Universidad San Francisco de Quito, McGill University, and Norwegian University of Science and Technology were on Santa Cruz Island when they found two forms of medium ground finches — a small and large version — while studying beak size at an isolated, pristine site.


When they repeated the same set of measurements at a nearby urban site, the distinction between the two beak sizes was not present. Studying data collected by other researchers in the 1970s, the researchers could see the two types of medium ground finches had been present in the area before, but something had changed in the last 40-50 years.


They hypothesized that the change might have to do with urbanization and the rapidly increasing human population in that area. In particular, the introduction of novel foods brought by humans.











Darwin's finches have developed a taste for junk food, and it may be impacting their evolution
Finches eat from an egg crate left by the researchers
[Credit: University of Massachusetts Boston]

Using egg crates filled with natural seeds and human junk food — chips, cookies, and rice — the researchers tested to see if the finches were in fact feeding on human food and what their preference was, weighing the food before and after to see how much was eaten.


De León said they found that finches in the urban area were almost exclusively feeding on human food. When the experiment was repeated at an isolated site in nature, the finches ignored the trays.


They found that “urban” finches feed on human junk foods, and in fact prefer these foods over their natural diet. This indicates that ongoing urbanization in the Galápagos is eroding the ecological differences that originally drove the formation of species in Darwin’s finches.


“In contrast to their natural diet, the finches are changing their diet to human junk food,” De León said. “We know one way finches diversify and become new species is by specializing in different food types. All three or four species of ground finches at urban sites on Santa Cruz Island seem to be converging onto the same junk food diet. If that’s the case, the selection pressures that would be naturally  keeping them apart would be weakening, possibly leading to the collapse of the adaptive radiation of ground finches.”


Researchers also found a strong preference for human foods at EG Beach, a non-urban site visited by tourists located 12 kilometers away from the town of Puerto Ayora. This suggests that human behavior, rather than human population density, is the main driver of finches’ preference for human food, expanding the impacts of urbanization beyond city centers.


Now that the researchers know that finches are changing their diets to human junk food, they need to look at the consequences for the actual evolution of the species on this island.


“When thinking about preserving biodiversity in general, we often focus on preserving individual species,” he said. “What we show with this work is we also need to consider preserving the processes that lead to the formation of species.”











Darwin's finches have developed a taste for junk food, and it may be impacting their evolution
Assistant Professor of Evolutionary Biology Luis De León studies Darwin’s finches
[Credit: University of Massachusetts Boston]

De León and a PhD student will return to the Galapagos in January.


De León said they will continue to do more genetic analysis, looking at whether there is an increase in gene flow across the four species of ground finch. Now that the birds are eating the same diet, researchers want to know if they are also interbreeding.


Elaine Montes, a second-year PhD student at UMass Boston who is working with De León, will look at the physiological consequences of human junk food on Galapagos finches by analyzing telomeres, a long chain of repetitive DNA at the end of every chromosome that can shorten due to stress and aging.


“We want to see whether they have a shorter life span than birds in nature,” he said.


De León has worked at UMass Boston for two years. He received his PhD at McGill University, where he started his work on Galapagos finches 14 years ago.


“It’s a fascinating place. Every species is so unique; it captures your imagination. You can imagine how Darwin was fascinated by looking at all those species,” he said. “I feel privileged to essentially walk in Darwin’s footsteps.”


Author: Crystal Valencia | Source: University of Massachusetts Boston [December 03, 2018]



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Ideal marriage partners drive Waorani warriors to war

Why do people go to war when the consequences of warfare are so dramatic? Scholars have suggested that the motivations for participating in war either lie in the individual rewards warriors receive (to the victor goes the spoils) or because group members coerce them to participate for fear of punishment. Understanding the factors that motivate warriors to join war parties sheds light on some of the most fundamental aspects of human nature: How our ability to cooperate is linked to our most destructive tendencies.











Ideal marriage partners drive Waorani warriors to war
In a new study, a team of researchers examined the social composition of raiding parties and their relationship
to marriage alliances in an Amazonian tribal society, the Waorani of Ecuador
[Credit: Pete Oxford/australscope]

In a new study, a team of researchers examined the social composition of raiding parties and their relationship to marriage alliances in an Amazonian tribal society, the Waorani of Ecuador. The Waorani formerly practiced lethal raiding, or small-scale warfare, as part of their social fabric. The anthropologists spoke in detail with tribal members about their raiding histories in an attempt to understand what drives individuals to participate in acts of war. Theirs is one of only a handful of datasets in the world with detailed information about what warfare looks like in small-scale societies prior to the intervention of the state.


They found that Waorani are actively joining raids with people who could provide access to ideal marriage partners for themselves as well as their children. Additionally, subtle coercion from in-laws appears to be a factor in joining raids. The relationships built through raiding resulted in meaningful bonds between the men, which could shed light on the evolution of friendship.


“A big debate in anthropology is what warfare and raiding groups look like in small-scale societies. Arguments have always been about this nice band of brothers–literally brothers, uncles, fathers all fighting side-by-side with one another,” said Shane Macfarlan, assistant professor of anthropology at the University of Utah and lead author of the study. “But sometimes, kin are not enough. Warfare is about alliance building, relationships with other people where there might be something else to gain by fighting with one another–like marriage partners.”


The Waorani


The Waorani are indigenous Ecuadorians from the lowlands of the Amazon Rainforest made up of 2,000 individuals today. When people of Euro-American descent first made contact with members of the tribe in 1958, the population consisted of 500 individuals residing in four mutually hostile territories. Within the territories, Waorani lived in neighborhoods of longhouses, called nanicabo. Each neighborhood was separated by a one- to two-days walk, and each nanicabo was separated by a 30- to 60-minute walk.











Ideal marriage partners drive Waorani warriors to war
The Waorani formerly practiced lethal raiding, or small-scale warfare, as part of their social fabric
[Credit: Kleverenrique/WikiCommons]

For the Waorani, the ideal marriage partners are bilateral cross cousins–for example a man’s mother’s brother’s daughter or his father’s sister’s daughter. One of the ways to make alliances is through raiding. Lethal raiding was quite common amongst the Waorani; when an individual decided to raid, he would convince followers to join him.


“The benefit of making an alliance outside of your direct kin is that it expands your social universe for getting the things that you need, and one of the things that people need in all societies is mating partners,” said Macfarlan.


Between 2000 and 2001, co-authors Jim Yost, Pam Erickson of University of Connecticut and Steve Beckerman of Pennsylvania State University interviewed almost all of the Waorani population aged 49 years or older–65 women and 55 men. The researchers collected detailed genealogical information from multiple generations, and cross-referenced the data with existing Waorani genealogies. They also collected raid histories that included the men who participated, the organizer, the victims, and the rationale for the attack. The researchers used marriages and births to establish a timeline of the raids. From 1917 to 1970, there were 550 raid reports. The researchers consolidated them into 49 separate raids that involved 81 people.


In-laws, brothers and marriage


Macfarlan and senior author Stephen Beckerman analyzed the make-up of the raiding groups and the raiders’ marriage histories. If the “bands of brothers” model holds, then the raiders should include mostly direct ancestors or descendants of each other, known as lineal kin. If the groups were strategic alliances, then the individuals should consist of men who can provide marriage opportunities for each other–genetically related, but outside of lineal kinship. Because the researchers needed to be able to distinguish cousins, they only used individuals for whom they had grandparents’ information. They analyzed the social composition of the 49 raids, including the 1041 individual relationships that emerged from the 81 men who participated.











Ideal marriage partners drive Waorani warriors to war
Co-author Jim Yost (right) with a Waorani man discussing Waorani
 territory during the data collection component of the project
[Credit: Jim Yost]

Although males had a plenty of lineal kin to choose from for forming raiding parties, they selectively raided with non-lineal kin. They also found that men raided more frequently with men who were generically related to them, but from different lineages–the ideal marriage exchange partners. Indeed, the raiding alliances resulted in marriages for both the raiders, and for the raiders’ children.


Yet another motivation to join raiding parties seemed to include some coercion. Macfarlan found that sometimes men got married first, then raided more frequently with his in-laws.


While scholars have typically assumed that warfare was either about individual rewards or coercion we find that this is a two-way street. “Sometimes people go to war to find alliance partners that gives them access to marriage opportunities, but other times guys get married first and then these marriage ties are leveraged to coerce people into warfare.”


Evolution of friendship


Humans for the most part have three kinds of relationships: kinship, marriage and friendship. Traditionally, anthropologists only considered kinship and marriage as important. Recent interest has looked into the evolution of friendship itself. A common feature of friendship across cultures is that it promotes cooperation between people who are neither are kin nor our lovers, with our friends providing us with benefits that kin and lovers cannot. One context where friendship is extremely important is helping us deal with conflict from other people and groups, known as the Alliance Hypothesis.


The study’s findings provide evidence for this hypothesis, Macfarlan said.


“The act of killing another human is a really traumatic act, which causes people to share something in common psychologically that establishes trust and fosters things like friendships,” said Macfarlan.


The study was published in the journal Proceedings of the Royal Society B.


Source: University of Utah [December 03, 2018]



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NASA Sends New Research, Hardware to Space Station on SpaceX Mission


SpaceX – CRS-16 Dragon patch.


Dec. 5, 2018



Image above: A SpaceX Dragon spacecraft launches to the International Space Station at 1:16 p.m. EST Dec. 5, 2018, on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. The spacecraft, on its 16th mission for NASA under the agency’s Commercial Resupply Services contract, carries more than 5,600 pounds of research equipment, cargo and supplies. Image Credits: NASA Television.


Experiments in forest observation, protein crystal growth and in-space fuel transfer demonstration are heading to the International Space Station following the launch Wednesday of SpaceX’s 16th mission for NASA under the agency’s Commercial Resupply Services contract.



Falcon 9 launches CRS-16 Dragon & Falcon 9 first stage failed landing

The company’s Dragon spacecraft lifted off at 1:16 p.m. EST on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. It’s carrying more than 5,600 pounds of research equipment, cargo and supplies that will support the crew, station maintenance and dozens of the more than 250 investigations aboard the space station.


Expedition 57 Commander Alexander Gerst of ESA (European Space Agency) and Flight Engineer Serena Auñón-Chancellor of NASA will use the space station’s robotic arm to capture Dragon when it arrives two days later. NASA astronaut Anne McClain will monitor telemetry during the spacecraft’s approach.


Live coverage of the rendezvous and capture will air on NASA Television and the agency’s website beginning at 4:30 a.m. Saturday, Dec. 8, with installation coverage set to begin at 7:30 a.m.


Science Aboard Dragon


The Global Ecosystem Dynamics Investigation (GEDI) will provide high-quality laser ranging observations of the Earth’s forests and topography required to advance the understanding of important carbon and water cycling processes, biodiversity, and habitat. GEDI will be mounted on the Japanese Experiment Module’s Exposed Facility and provide the first high-resolution observations of forest vertical structure at a global scale. These observations will quantify the aboveground carbon stored in vegetation and changes that result from vegetation disturbance and recovery, the potential for forests to sequester carbon in the future, and habitat structure and its influence on habitat quality and biodiversity.


A small satellite deployment mechanism, called SlingShot, will be ride up in Dragon and then be installed in a Northrop Grumman Cygnus spacecraft prior to its departure from the space station. SlingShot can accommodate as many as 18 CubeSats of any format. After the Cygnus cargo ship departs from station, the spacecraft navigates to an altitude of 280 to 310 miles (an orbit higher than
that of the space station) to deploy the satellites.



SpaceX Dragon. Animation Credit: NASA

Robotic Refueling Mission-3 (RRM3) will demonstrate the first transfer and long-term storage of liquid methane, a cryogenic fluid, in microgravity. The ability to replenish and store cryogenic fluids, which can function as a fuel or coolant, will help enable long duration journeys to destinations, such as the Moon and Mars.


Growth of Large, Perfect Protein Crystals for Neutron Crystallography (Perfect Crystals) crystallizes an antioxidant protein found inside the human body to analyze its shape. This research may shed light on how the protein helps protect the human body from ionizing radiation and oxidants created as a byproduct of metabolism. For best results, analysis requires large crystals with minimal imperfections, which are more easily produced in the microgravity environment of the space station.


Dragon is scheduled to depart the station in January 2019 and return to Earth with more than 4,000 pounds of research, hardware and crew supplies.


For more than 18 years, humans have lived and worked continuously aboard the International Space Station, advancing scientific knowledge and demonstrating new technologies, making research breakthroughs not possible on Earth that will enable long-duration human and robotic exploration into deep space. A global endeavor, more than 200 people from 18 countries have visited the unique microgravity laboratory that has hosted more than 2,500 research investigations from researchers in 106 countries.


Related links:


SpaceX: http://www.nasa.gov/spacex


NASA Television: https://www.nasa.gov/live


Global Ecosystem Dynamics Investigation (GEDI): https://www.nasa.gov/feature/goddard/2018/gedi-to-measure-earths-forests


SlingShot: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7847


Robotic Refueling Mission-3 (RRM3): https://orbiterchspacenews.blogspot.com/2018/11/nasa-to-launch-new-refueling-mission.html


Perfect Crystals: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7617


Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Image (mentioned), Animation (mentioned), Video, Text, Credits: NASA/Kathryn Hambleton/Karen Northon/JSC/Gary Jordan/SpaceX/SciNews.


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NASA Science Shows Human Impact of Clean Air Policies


NASA logo.


Dec. 5, 2018


As local, federal, and international policies targeting the quality of the air we breathe continue to evolve, questions arise of how effective existing policies have been in improving human health. For example, how many lives have been saved by tough air pollution policies? How many illnesses have been caused by lax policies?



Image above: Annual mean levels of fine particulate matter (PM2.5) pollution declined in the United States between 1990 (left) and 2010 (right), leading to thousands of lives saved, according to researcher Jason West. Image Credit: Atmospheric Chemistry and Physics.


NASA recently initiated two projects to provide some answers drawing on its scientific expertise and global observations of air pollution from spacecraft orbiting Earth. It is information air quality managers say they need to refine current policies and develop effective new ones.


One project demonstrated that improvements in air quality in the United States between 1990 and 2010 reduced deaths from air pollution by nearly half. The other project, taking a global view of asthma, found that high levels of air pollution caused millions of emergency room visits annually.



Image above: The study of asthma impacts caused by air pollution used data on several pollutants including ozone. Shown here are annual average ozone concentrations from 2015; red indicates high concentrations, blue indicates lower levels. Image Credit: Environmental Health Perspectives.


Both projects are part of NASA’s ongoing efforts to help air quality managers and policymakers solve clean air problems using NASA data and products. These quick-turnaround, high-priority projects are funded by the agency’s Earth Science Division drawing on expertise in its Health and Air Quality Applied Sciences Team.


The project that focused on U.S. air quality improvements used a 21-year computer simulation to estimate air pollutant concentrations, combining that with county population and baseline mortality rates. The findings showed that pollution-related deaths from heart disease, pulmonary disease, lung cancer, and stroke declined as a result of air quality improvements.


“We’ve invested a lot of resources as a society to clean up our air,” said study co-author Jason West, professor of environmental sciences and engineering at the University of North Carolina, Chapel Hill. “This study demonstrates that those changes have had a real impact with fewer people dying each year due to exposure to outdoor air pollution.”



Image above: Jason West, University of North Carolina: “We’ve invested a lot of resources as a society to clean up our air. Our study demonstrates that those changes have had a real impact with fewer people dying each year due to exposure to outdoor air pollution.” Image Credit: University of North Carolina.


In 2010 alone, the study, published in Atmospheric Chemistry and Physics, found that some 40,000 lives were saved, compared to levels projected if air quality stayed at 1990 levels. Deaths from air pollution over this period decreased by 47 percent, from 135,000 to 71,000.


Paul Miller, deputy director of Northeast States for Coordinated Air Use Management in Boston, explained that West’s study provides a necessary retrospective view on the effect of air quality policy.


“We rarely have the time or resources to take a look back at what has been achieved and what has not,” Miller said. “West’s research can verify whether air quality strategies are helping us make progress and build confidence in our public health efforts.” 


Julie McDill, executive director the Mid-Atlantic Regional Air Management Association Inc. in Baltimore, shared that West’s findings will help her explain the importance of finding solutions for air quality challenges.


“I will be able to use the information about the number of lives saved as a result of fine particulate matter and ozone reductions when talking in general about the importance of air pollution control programs to human health,” she said.



Image above: Susan Anenberg, George Washington University: “Our findings suggest that policies aimed at cleaning up the air can reduce the global burden of asthma and improve respiratory health around the world.” Image Credit: George Washington University.


The second project, led by Susan Anenberg, associate professor of environmental and occupational health at the George Washington University, Washington, quantified air pollution’s impact on asthma cases around the globe. The team used atmospheric models, ground monitors, and data from NASA’s Aura spacecraft.


That study in Environmental Health Perspectives found that 9-23 million and 5-10 million annual visits to the emergency room for asthma worldwide in 2015 may have resulted from breathing in air polluted by ozone and fine particulate matter respectively, and that car emissions and other types of pollution may be a significant source of serious asthma attacks.


“Our findings suggest that policies aimed at cleaning up the air can reduce the global burden of asthma and improve respiratory health around the world,” Anenberg said.


According to Anenberg, nonprofits, policymakers, and air quality researchers can put these findings to work by using them to target known sources of pollution like ozone, fine particulate matter, and nitrogen dioxide.


Getting these types of science-based findings about the health impacts of air pollution out to policymakers, air quality managers and the public is another goal of West’s project. Team member Bryan Duncan, an atmospheric scientist at NASA Goddard Space Flight Center, Greenbelt, Maryland, is nearing completion of an online resource filled with satellite-based air quality estimates, health impacts, and data on ozone, fine particulate matter, and other pollutants. The new resource will be posted on the Air Quality Observations from Space website at NASA Goddard.


Related links:


Atmospheric Chemistry and Physics: https://www.atmos-chem-phys.net/18/15003/2018/


Environmental Health Perspectives: https://ehp.niehs.nih.gov/doi/full/10.1289/EHP3766


Air Quality Observations from Space: https://airquality.gsfc.nasa.gov/


Images (mentioned), Text, Credits: NASA/Sarah Loff/Steve Cole.


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New discovery complicates efforts to measure universe’s expansion

A study led by Texas Tech University shows that supersoft X-ray emissions can come from accretion as well as nuclear fusion.











New discovery complicates efforts to measure universe's expansion
Credit: NASA/CXC/M.Weiss

For decades, astronomers and astrophysicists have used a specific type of supernova to measure the expansion of the universe. But a recent discovery led by Texas Tech University may turn that notion on its head.


Supersoft X-ray emission – a very strong level of the weakest X-rays – has long been considered a result of nuclear fusion on the surface of a white dwarf, a small, very dense star. But a new detection of supersoft emissions that are clearly not powered by fusion is showing scientists that fusion is not the only way such emissions occur, according to a study published in the journal Nature Astronomy.


The event, ASASSN16-oh, was first noticed as a transient in the Small Magellanic Cloud by the All-Sky Automated Survey. Additional observations from NASA’s Swift Observatory and the Chandra X-ray Observatory helped to verify the finding.


“In the past, the supersoft sources have all been associated with nuclear fusion on the surface of white dwarfs,” said lead author Tom Maccarone, a professor in the Texas Tech Department of Physics & Astronomy. “As a white dwarf captures material from a companion star, the material piles up on the surface and becomes hot, and, eventually nuclear fusion takes place, much like in a hydrogen bomb.


“But this emission is coming from a region smaller than the surface of the white dwarf, and we have strong arguments against any kind of explosion having taken place on the white dwarf. Specifically, there are no broad emission lines in the X-ray or optical spectra, so there cannot have been any kind of strong wind generated. In some cases, nuclear fusion can be steady on the surface of a white dwarf, but it cannot start immediately as steady fusion. There must be an explosion of some kind when the fusion starts.”


The source of these emissions, then, is thought to be accretion – the process of accumulating matter – not fusion. The scientists believe the system consists of a highly evolved red giant star and a white dwarf with an extremely large disk of emission around it. The rate of inflow of matter through the disk is unstable, and when the material starts flowing more quickly, the brightness of the system shoots upward.


“What we’re seeing here is a transient episode of supersoft emission, but without any of the signs that we associate with nuclear fusion,” Maccarone said. “If a nova took place, we would expect to see material flowing away from the white dwarf. Here we don’t. Instead, what we are seeing is hot emission from the disk that is transporting the material from the companion star to the white dwarf. The transfer of mass is happening at a higher rate than in any system we’ve caught in the past.”


So what this finding shows is that there are two ways by which supersoft emission can be made: nuclear fusion and accretion.


“I am excited by this result,” Maccarone said. “It was a totally new phenomenon, and any time one finds one of those, it’s exciting.”


As exciting as this finding is on its own, perhaps the most important part is that it may change how astrophysicists measure the expansion of the universe. These objects were thought to be one of the main ways by which white dwarfs grow in mass and eventually explode as Type Ia supernovae.


“These systems also are the way we measure the expansion of the universe,” Maccarone said. “To measure that expansion more accurately than we do now, we need to understand the origin of the Type Ia supernovae. This finding – that there’s a new way to make supersoft sources – will cause us to re-think our approach to matching up the populations of these objects with the rates of the supernovae.”


Author: Glenys Young | Source: Texas Tech University [December 04, 2018]



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Set your teeth on EDGE: World’s weirdest sharks and rays on the brink of extinction

Sharks that use a whip-like tail to stun their prey, rays with saws on their faces, and river rays half the length of a bus are among the most unique species at risk of extinction according to the latest ranking from international conservation charity ZSL’s (Zoological Society of London) pioneering EDGE of Existence programme.











Set your teeth on EDGE: World's weirdest sharks and rays on the brink of extinction
The largetooth sawfish (Pristis pristis) is not only #1 on the EDGE sharks and rays list, but is also the highest ranking
 EDGE species across all the different animal groups ranked, including corals, reptiles, amphibians, mammals
and birds [Credit: (c) Simon Fraser University]

The new list revealed today (4 December) ranks the world’s 50 most Evolutionarily Distinct and Globally Endangered (EDGE) sharks, rays and chimeras – known collectively as Chondrichthyes.


These mythical-sounding (but very real) creatures have no bones in their bodies, only cartilage and appeared more than 400 million years ago, roaming the seas when dinosaurs lived. Each species on this list has few or no remaining close relatives, effectively representing distinct branches of the tree of life and making each of them truly irreplaceable. If they go extinct, we will have nothing like them left on the planet.


Topping the new list, at number one is the largetooth sawfish (Pristis pristis), which also holds the distinction of being the highest-ranking EDGE species in the world. Using an elongated snout (rostrum) lined with teeth on each side to slash at its prey, the large-tooth sawfish is facing threats from unsustainable fishing activities as it’s often caught as by-catch in nets.


Despite the fearsome reputation of the great white shark and the well-recognised appearance of the hammerhead, sharks are one of the least-studied groups of animals – some so elusive they’ve never been captured on camera. Many of these species are threatened by targeted fishing, driven by a desire for shark fins or other body parts, as well as being unintentionally caught (bycatch).


Habitat degradation, due to coastal development, mangrove deforestation, water pollution and trawling, is also to blame for the steep decline in many of these populations. However, the new EDGE List gives conservationists another tool to identify and prioritise species where there is a most pressing need for action.


EDGE Sharks co-ordinator and marine biologist, Fran Cabada said: “Sharks, rays and chimeras – making up the cartilaginous fish, have been around since the age of the dinosaurs, but due to human activities, their modern relatives are facing threats all over the world. They’re found in almost every aquatic environment and as many are apex predators, i.e., at the top of the food chain – they’re crucial to maintaining healthy ecosystems.











Set your teeth on EDGE: World's weirdest sharks and rays on the brink of extinction
Representative phylogeny tree (taxon-complete) of Chondrichthyes. Red dotes highlight
nodes defining orders [Credit: 
Stein et al. (2018)/EDGE]

“Unfortunately, sharks have a bad image. This means people often can’t see beyond the negative, and usually exaggerated stories, and don’t understand just how threatened and important they are.


“The new EDGE Sharks and Rays list gives us the opportunity to highlight the most unique sharks and rays on our planet which are also the most endangered, so that we can target conservation efforts where it’s needed most. Many are overlooked and poorly known, so conservation actions targeted at these survivors of ancient lineages should be prioritised.”


ZSL’s Marine and Freshwater Conservation Programme Manager, Dr. Matthew Gollock added: “The EDGE Sharks and Rays list comprises some of the most interesting and unique fish we have on this planet. The modern extinction of a single species from this list would cause the loss of millions of years of evolutionary history.


“Since 2013, we have been working in collaboration with partner organisations in the Canary Islands for the conservation of the angel shark (Squatina squatina), #5 in the EDGE list, increasing our knowledge of this species and working with divers, fishers and policymakers to improve management and policy.


“Our successes from this project have allowed us to expand our work to Wales, UK, where we have taken a similar stakeholder-lead approach to collect sightings and community memories of the angel shark in order to better understand and conserve this Critically Endangered species across its range.”


First established in 2007, the EDGE of Existence programme has previously published lists for amphibians, birds, corals, mammals and reptiles. The EDGE lists provide conservationists worldwide with a scientifically rigorous method of focusing their conservation efforts on animals and plants that represent a significant amount of threatened evolutionary history.


ZSL’s EDGE of Existence programme works with partners including the National Geographic Photo Ark and Fondation Segré to fund early-career conservationists striving to secure the future of EDGE species all around the world, through the EDGE Fellowship initiative. The first ever EDGE Fellowships on Sharks and Rays will begin in early 2019, implementing conservation actions for the largetooth sawfish and the pelagic thresher shark (Alopias pelagicus) in Asia.


For more information please see the original paper presenting ED values for these species.


Click here to explore the Top 50 EDGE Sharks and Rays List.


Click here for the latest EDGE Sharks and Rays List.


Source: Zoological Society of London [December 04, 2018]



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Microplastics found in all sea turtle species

Tests on more than 100 sea turtles—spanning three oceans and all seven species—have revealed microplastics in the guts of every single turtle.











Microplastics found in all sea turtle species
Credit: Belle Co, Pexels.com

Researchers from the University of Exeter and Plymouth Marine Laboratory, working with the Greenpeace Research Laboratories, looked for synthetic particles (less than 5mm in length) including microplastics in 102 sea turtles in the Atlantic, Pacific and Mediterranean.


Synthetic particles were found in all of the turtles, the most common being fibres, which can potentially come from sources including clothing, tyres, cigarette filters and maritime equipment such as ropes and fishing nets.


“The effect of these particles on turtles is unknown,” said lead author Dr. Emily Duncan, of the Centre for Ecology and Conservation on the University of Exeter’s Penryn Campus in Cornwall.


“Their small size means they can pass through the gut without causing a blockage, as is frequently reported with larger plastic fragments. However, future work should focus on whether microplastics may be affecting aquatic organisms more subtly. For example, they may possibly carry contaminants, bacteria or viruses, or they may affect the turtle at a cellular or subcellular level. This requires further investigation.”


In total, more than 800 synthetic particles were found in the 102 turtles studied. But researchers only tested part of each animal’s gut—so the total number of particles is estimated to be about 20 times higher.


Researchers do not currently understand how synthetic particles are ingested by turtles, but the likely sources are polluted seawater and sediments, and eating via prey or plants.


Professor Brendan Godley, senior author of the study, added: “It really is a great shame that many or even all of the world’s sea turtles have now ingested microplastics. At the moment, this is not the main threat to this species group but it is a clear sign that we need to act to better govern global waste.”


Necropsies were carried out on the turtles after they died either by stranding or bycatch (accidental catching in fishing). The study sites were North Carolina, USA (Atlantic), Northern Cyprus (Mediterranean) and Queensland, Australia (Pacific).


The turtles with the most synthetic particles were in the Mediterranean—thought to have higher rates of contamination than the Atlantic or Pacific—but this study’s sample sizes and methodology did not allow for detailed geographical comparisons.


Dr. Penelope Lindeque, of Plymouth Marine Laboratory, said: “While this study has been successful, it does not feel like a success to have found microplastic in the gut of every single turtle we have investigated.


“From our work over the years we have found microplastic in nearly all the species of marine animals we have looked at; from tiny zooplankton at the base of the marine food web to fish larvae, dolphins and now turtles. This study provides more evidence that we all need to help reduce the amount of plastic waste released to our seas and maintain clean, healthy and productive oceans for future generations.”


Louise Edge, plastics campaigner at Greenpeace, said: “This important research demonstrates the breadth of our plastics pollution problem. Our society’s addiction to throwaway plastic is fuelling a global environmental crisis that must be tackled at source.”


The paper is published in the journal Global Change Biology.


Source: University of Exeter [December 04, 2018]



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New parasite decimates giant clam species in Mediterranean

With rapid efficiency, a mysterious parasite is seeking out and killing a giant species of clam found only in the Mediterranean Sea. Unless scientists can find a way of stopping it soon, they say the mollusk could go extinct.











New parasite decimates giant clam species in Mediterranean
A diver observes a pen shell on the seabed in the Aegean Sea
[Credit: Yiannis Issaris/AP]

For thousands of years, the emblematic noble pen shell has been intrinsically connected to human civilization. The largest bivalve in the Mediterranean can grow to more than a meter (three feet) long and has provided food and one of the world’s rarest materials: sea silk spun from fibers it uses to secure itself to the seabed. The mollusk also contributes to clear water by filtering out organic particulates.
The pen shell, Pinna nobilis, has been on the European Union’s protected species list for decades because of overfishing, pollution and the destruction of its natural habitat, meaning any fishing is banned. But the ban is often poorly enforced, with the animal harvested for food or for its shell, which is used for decorative purposes.











New parasite decimates giant clam species in Mediterranean
A pen shell stands on the seabed of the Aegean Sea
[Credit: Yiannis Issaris/AP]

The pen shells, which have a life span of several decades and take years to reach reproductive age, were already dying faster than they could be replaced. So the spread of the microscopic parasite, which first appeared in the western Mediterranean in late 2016 and was identified just this year as a new species, has alarmed experts.


Exactly how the parasite kills isn’t completely clear, although scientists have found it attacks the pen shell’s digestive system. The infected animal is also unable to close its shell, incapacitating its defense against predators. Once infected, death is almost certain.











New parasite decimates giant clam species in Mediterranean
Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research,
holds a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens
[Credit: Thanassis Stavrakis/AP]

“In less than a year it wiped out (the pen shell population of) the Spanish coast,” said Maria del Mar Otero of the International Union for Conservation of Nature.


Soon parts of France, Malta, Tunisia and Italy were affected. In recent weeks, tests confirmed the same parasite, Haplosporidium pinnae, is responsible for pen shell die-offs in parts of Greece, and researchers have reported mass mortality as far east as Turkey and Cyprus.











New parasite decimates giant clam species in Mediterranean
Pen shells stand on the seabed in the Aegean Sea
[Credit: Yiannis Issaris/AP]

Scientists are now racing to understand how the parasite spreads and its life cycle — essential information for a successful rescue program. One theory is that it could be spreading through phytoplankton, the bivalve’s food source, but nobody knows for certain.
“We cannot be sure of anything at this point,” said Pantelis Katharios, senior researcher at the Institute of Marine Biology, Biotechnology and Aquaculture of the Hellenic Center for Marine Research, or HCMR.











New parasite decimates giant clam species in Mediterranean
A dead pen shell stands open in a seagrass meadow in the Aegean Sea’s Saronic Gulf
[Credit: Elena Becatoros]

“What we know now is that the Pinnas are dying, that the cause is this parasite, and we know that it’s spreading very, very rapidly,” he said. “And that is going to be a huge problem (for) the ecology and the balance of the ecosystem in the Mediterranean.”


Yiannis Issaris, marine ecologist at the HCMR’s Institute of Oceanography, initially noticed widespread pen shell death off the coast of Anavyssos, southeast of Athens, in mid-summer. He suspected the culprit could be the same one causing mortality in Spain — and testing proved him right.











New parasite decimates giant clam species in Mediterranean
A pen shell stands anchored in the seabed of the Aegean Sea
[Credit: Yiannis Issaris/AP]

Now the question is how to tackle the outbreak.


“This is very fresh for the scientific community,” Issaris said. “We’re still at the stage of recording where it has spread to.”











New parasite decimates giant clam species in Mediterranean
Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research,
takes measurements of a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens
[Credit: Thanassis Stavrakis/AP]

Some parts of Greece still have healthy populations of the mollusks, he noted, whereas in other areas they have been wiped out.
Protecting the pen shell in its natural habitat — sandy seabeds or seagrass meadows — appears “difficult to impossible,” Issaris said, particularly without knowing how the parasite spreads. In Spain, some healthy individuals were moved to aquariums.











New parasite decimates giant clam species in Mediterranean
Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research,
takes measurements of a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens
[Credit: Thanassis Stavrakis/AP]

Although tests are pending in some Mediterranean countries witnessing mass die-offs, experts have little doubt what the results will show.


“It’s very, very, very likely” to be the same parasite, Otero said. “There’s almost no question.”











New parasite decimates giant clam species in Mediterranean
Christina Pavloudi, foreground, post-doctoral researcher at the Hellenic Center for Marine Research laboratory
on the Greek island of Crete, and Georgia Sarafidou, a student at the same facility, carry out tests on samples
of noble pen shells stricken by a new parasite [Credit: Thanassis Stavrakis/AP]

One thing’s clear: the parasite is very particular in its choice of victim. A smaller, related species, the Pinna rudis, which also exists outside the Mediterranean, is unaffected.


“We don’t know how it has appeared in the Mediterranean… We only know that it causes mortality only in the Pinna nobilis,” Issaris said.











New parasite decimates giant clam species in Mediterranean
Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research,
holds a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens
[Credit: Thanassis Stavrakis/AP]

In the clear, shallow waters south of the Greek capital, dozens of dead pen shells lie scattered in a seagrass meadow, testament to the devastation.
Peering through a microscope at the tissue of an infected individual in his office in Crete, Katharios points out the culprit: small, oval-shaped parasites spread throughout the sample.


Scientists are puzzling over why an organism would be so lethal to the very species it depends on for its own survival.











New parasite decimates giant clam species in Mediterranean
Pantelis Katharios, senior researcher at the Institute of Marine Biology, Biotechnology and Aquaculture of the Hellenic
Center for Marine Research on the Greek island of Crete, checks microscope imaging of a new parasite killing
 the noble pen shell, or Pinna nobilis [Credit: Elena Becatoros]

“Normally parasites in nature do not have any benefit from harming the host, because they depend on the host,” Katharios explained. “But once in a while we may come across incidents like this, where we have massive mortalities.”


This could just be a natural phenomenon in which the parasite will eventually be wiped out along with its host, he said. Another possibility is that it originated in a different species and for some reason jumped to the pen shell. A third is that the pen shell’s immune system has been compromised by factors such as pollution, climate change or water temperature fluctuations.


“It’s extremely, extremely difficult to find the truth at this stage,” Katharios said.


Author: Elena Becatoros | Source: Associated Press [December 04, 2018]



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