A new beaked whale species Berardius minimus, which has been long postulated by local whalers in Hokkaido, Japan, has been confirmed.
In a collaboration between the National Museum of Nature and Science, Hokkaido University, Iwate University, and the United States National Museum of Natural History, a beaked whale species which has long been called Kurotsuchikujira (black Baird's beaked whale) by local Hokkaido whalers has been confirmed as the new cetacean species Berardius minimus (B. minimus).
Beaked whales prefer deep ocean waters and have a long diving capacity, making them hard to see and inadequately understood. The Stranding Network Hokkaido, a research group founded and managed by Professor Takashi F. Matsuishi of Hokkaido University, collected six stranded un-identified beaked whales along the coasts of the Okhotsk Sea.
The whales shared characteristics of B. bairdii (Baird's beaked whale) and were classified as belonging to the same genus Berardius. However, a number of distinguishable external characteristics, such as body proportions and color, led the researchers to investigate whether these beaked whales belong to a currently unclassified species.
"Just by looking at them, we could tell that they have a remarkably smaller body size, more spindle-shaped body, a shorter beak, and darker color compared to known Berardius species," explained Curator Emeritus Tadasu K. Yamada of the National Museum of Nature and Science from the research team.
In the current study, the specimens of this unknown species were studied in terms of their morphology, osteology, and molecular phylogeny. The results, published in the journal Scientific Reports, showed that the body length of physically mature individuals is distinctively smaller than B. bairdii (6.2-6.9m versus 10.0m). Detailed cranial measurements and DNA analyses further emphasized the significant difference from the other two known species in the genus Berardius. Due to it having the smallest body size in the genus, the researchers named the new species B. minimus.
"There are still many things we don't know about B. minimus," said Takashi F. Matsuishi. "We still don't know what adult females look like, and there are still many questions related to species distribution, for example. We hope to continue expanding what we know about B. minimus."
Local Hokkaido whalers also refer to some whales in the region as Karasu (crow). It is still unclear whether B. minimus (or Kurotsuchikujira) and Karasu are the same species or not, and the research team speculate that it is possible Karasu could be yet another different species.
Read more at Science Daily
Sep 3, 2019
Human perception of colors does not rely entirely on language
After patient RDS (identified only by his initials for privacy) suffered a stroke, he experienced a rare and unusual side effect: when he saw something red, blue, green, or any other chromatic hue, he could not name the object's color.
Using RDS as a subject, a study publishing on September 3 in the journal Cell Reports looks at how language shapes human thinking. Neuroscientists and philosophers have long wrestled with the interaction between language and thought: do names shape the way we categorize what we perceive, or do they correspond to categories that arise from perception?
To name the color red, for instance, we think of a red item as one of many in a vaguely defined spectrum that encompasses the concept "red." In this sense, we perform an act of categorization each time we call something by its name -- we group colors into discrete categories to identify mustard as a shade of yellow, for instance, or place teal in the blue family.
Senior author Paolo Bartolomeo, a neurologist at the Brain and Spine Institute in Salpêtrière Hospital in Paris, says, "We perceive colors as continuous. There is no sharp boundary between, say, red and blue. And yet conceptually we group colors into categories associated with color names.
"In our study, we had the unique opportunity to address the role of language in color categorization by testing a patient who couldn't effectively name colors after a stroke," he says.
Many scientists believe categorizing colors depends on top-down input from the language system to the visual cortex. Color names are believed to be stored in the brain's left hemisphere and to depend on language-related activity in the left side of the brain.
Conversely, these latest findings support recent neuroimaging studies suggesting that color categorization is distributed bilaterally in the human brain.
Viewing discs containing two colors from the same color category (e.g., two blue shades) or from different categories (e.g., brown and red), RDS was asked to identify same-category colors. He was also asked to name 34 color patches presented on a computer screen; eight of these patches were achromatic (white, black and grey), and 26 were chromatic.
Before his stroke, RDS perceived and named colors normally. After the stroke, an MRI revealed a lesion in the left region of his brain. This lesion apparently severed RDS's memory of color names from his visual perception of colors and his language system. Yet RDS could still group most colors -- even colors he couldn't name -- into categories such as dark or light or as being a mixture of other colors.
"We were surprised by his ability to consistently name so-called achromatic colors such as black, white, and gray, as opposed to his impaired naming of chromatic ones such as red, blue, and green," says the first author of the study, PhD student Katarzyna Siuda-Krzywicka. This suggested that our language system may process black, white, and gray differently from chromatic colors. Such striking dissociations raise important questions about how different color-related signals are segregated and integrated in the brain, she says.
To ensure that RDS's behavior did not reflect abnormal brain organization, the researchers compared the functioning of his unaffected brain areas to that of the same brain areas in healthy subjects and developed a non-verbal color-categorization test. "Our result -- that his color categories were independent from language -- could be generalized to healthy adults," Bartolomeo says.
Read more at Science Daily
Using RDS as a subject, a study publishing on September 3 in the journal Cell Reports looks at how language shapes human thinking. Neuroscientists and philosophers have long wrestled with the interaction between language and thought: do names shape the way we categorize what we perceive, or do they correspond to categories that arise from perception?
To name the color red, for instance, we think of a red item as one of many in a vaguely defined spectrum that encompasses the concept "red." In this sense, we perform an act of categorization each time we call something by its name -- we group colors into discrete categories to identify mustard as a shade of yellow, for instance, or place teal in the blue family.
Senior author Paolo Bartolomeo, a neurologist at the Brain and Spine Institute in Salpêtrière Hospital in Paris, says, "We perceive colors as continuous. There is no sharp boundary between, say, red and blue. And yet conceptually we group colors into categories associated with color names.
"In our study, we had the unique opportunity to address the role of language in color categorization by testing a patient who couldn't effectively name colors after a stroke," he says.
Many scientists believe categorizing colors depends on top-down input from the language system to the visual cortex. Color names are believed to be stored in the brain's left hemisphere and to depend on language-related activity in the left side of the brain.
Conversely, these latest findings support recent neuroimaging studies suggesting that color categorization is distributed bilaterally in the human brain.
Viewing discs containing two colors from the same color category (e.g., two blue shades) or from different categories (e.g., brown and red), RDS was asked to identify same-category colors. He was also asked to name 34 color patches presented on a computer screen; eight of these patches were achromatic (white, black and grey), and 26 were chromatic.
Before his stroke, RDS perceived and named colors normally. After the stroke, an MRI revealed a lesion in the left region of his brain. This lesion apparently severed RDS's memory of color names from his visual perception of colors and his language system. Yet RDS could still group most colors -- even colors he couldn't name -- into categories such as dark or light or as being a mixture of other colors.
"We were surprised by his ability to consistently name so-called achromatic colors such as black, white, and gray, as opposed to his impaired naming of chromatic ones such as red, blue, and green," says the first author of the study, PhD student Katarzyna Siuda-Krzywicka. This suggested that our language system may process black, white, and gray differently from chromatic colors. Such striking dissociations raise important questions about how different color-related signals are segregated and integrated in the brain, she says.
To ensure that RDS's behavior did not reflect abnormal brain organization, the researchers compared the functioning of his unaffected brain areas to that of the same brain areas in healthy subjects and developed a non-verbal color-categorization test. "Our result -- that his color categories were independent from language -- could be generalized to healthy adults," Bartolomeo says.
Read more at Science Daily
Reactor turns greenhouse gas into pure liquid fuel
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| Models of carbon dioxide molecules |
The catalytic reactor developed by the Rice University lab of chemical and biomolecular engineer Haotian Wang uses carbon dioxide as its feedstock and, in its latest prototype, produces highly purified and high concentrations of formic acid.
Formic acid produced by traditional carbon dioxide devices needs costly and energy-intensive purification steps, Wang said. The direct production of pure formic acid solutions will help to promote commercial carbon dioxide conversion technologies.
The method is detailed in Nature Energy.
Wang, who joined Rice's Brown School of Engineering in January, and his group pursue technologies that turn greenhouse gases into useful products. In tests, the new electrocatalyst reached an energy conversion efficiency of about 42%. That means nearly half of the electrical energy can be stored in formic acid as liquid fuel.
"Formic acid is an energy carrier," Wang said. "It's a fuel-cell fuel that can generate electricity and emit carbon dioxide -- which you can grab and recycle again.
"It's also fundamental in the chemical engineering industry as a feedstock for other chemicals, and a storage material for hydrogen that can hold nearly 1,000 times the energy of the same volume of hydrogen gas, which is difficult to compress," he said. "That's currently a big challenge for hydrogen fuel-cell cars."
Two advances made the new device possible, said lead author and Rice postdoctoral researcher Chuan Xia. The first was his development of a robust, two-dimensional bismuth catalyst and the second a solid-state electrolyte that eliminates the need for salt as part of the reaction.
"Bismuth is a very heavy atom, compared to transition metals like copper, iron or cobalt," Wang said. "Its mobility is much lower, particularly under reaction conditions. So that stabilizes the catalyst." He noted the reactor is structured to keep water from contacting the catalyst, which also helps preserve it.
Xia can make the nanomaterials in bulk. "Currently, people produce catalysts on the milligram or gram scales," he said. "We developed a way to produce them at the kilogram scale. That will make our process easier to scale up for industry."
The polymer-based solid electrolyte is coated with sulfonic acid ligands to conduct positive charge or amino functional groups to conduct negative ions. "Usually people reduce carbon dioxide in a traditional liquid electrolyte like salty water," Wang said. "You want the electricity to be conducted, but pure water electrolyte is too resistant. You need to add salts like sodium chloride or potassium bicarbonate so that ions can move freely in water.
"But when you generate formic acid that way, it mixes with the salts," he said. "For a majority of applications you have to remove the salts from the end product, which takes a lot of energy and cost. So we employed solid electrolytes that conduct protons and can be made of insoluble polymers or inorganic compounds, eliminating the need for salts."
The rate at which water flows through the product chamber determines the concentration of the solution. Slow throughput with the current setup produces a solution that is nearly 30% formic acid by weight, while faster flows allow the concentration to be customized. The researchers expect to achieve higher concentrations from next-generation reactors that accept gas flow to bring out pure formic acid vapors.
The Rice lab worked with Brookhaven National Laboratory to view the process in progress. "X-ray absorption spectroscopy, a powerful technique available at the Inner Shell Spectroscopy (ISS) beamline at Brookhaven Lab's National Synchrotron Light Source II, enables us to probe the electronic structure of electrocatalysts in operando -- that is, during the actual chemical process," said co-author Eli Stavitski, lead beamline scientist at ISS. "In this work, we followed bismuth's oxidation states at different potentials and were able to identify the catalyst's active state during carbon dioxide reduction."
With its current reactor, the lab generated formic acid continuously for 100 hours with negligible degradation of the reactor's components, including the nanoscale catalysts. Wang suggested the reactor could be easily retooled to produce such higher-value products as acetic acid, ethanol or propanol fuels.
Read more at Science Daily
How humans have shaped dogs' brains
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| Puppies of various dog breeds |
Over several hundred years, humans have selectively bred dogs to express specific physical and behavioral characteristics. Erin Hecht and colleagues investigated the effects of this selective pressure on brain structure by analyzing magnetic resonance imaging scans of 33 dog breeds. The research team observed wide variation in brain structure that was not simply related to body size or head shape.
The team then examined the areas of the brain with the most variation across breeds. This generated maps of six brain networks, with proposed functions varying from social bonding to movement, that were each associated with at least one behavioral characteristic. The variation in behaviors across breeds was correlated with anatomical variation in the six brain networks.
Studying the neuroanatomical variation in dogs offers a unique opportunity to study the evolutionary relationship between brain structure and behavior.
The article, "Significant Neuroanatomical Variation Among Domestic Dog Breeds," appears online Sept. 2, 2019 in the Journal of Neuroscience.
From Science Daily
Sep 2, 2019
What if we paid countries to protect biodiversity?
Researchers from Sweden, Germany, Brazil and the USA have developed a financial mechanism to support the protection of the world's natural heritage. In a recent study, they developed three different design options for an intergovernmental biodiversity financing mechanism. Asking what would happen if money was given to countries for providing protected areas, they simulated where the money would flow, what type of incentives this would create -- and how these incentives would align with international conservation goals.
After long negotiations, the international community has agreed to safeguard the global ecosystems and improve on the status of biodiversity. The global conservation goals for 2020, called the Aichi targets, are an ambitious hallmark. Yet, effective implementation is largely lacking. Biodiversity is still dwindling at rates only comparable to the last planetary mass extinction. Additional effort is required to reach the Aichi targets and even more so to halt biodiversity loss.
"Human well-being depends on ecological life support. Yet, we are constantly losing biodiversity and therefore the resilience of ecosystems. At the international level, there are political goals, but the implementation of conservation policies is a national task. There is no global financial mechanism that can help nations to reach their biodiversity targets," says lead author Nils Droste from Lund University, Sweden.
Brazil has successfully implemented Ecological Fiscal Transfer systems that compensate municipalities for hosting protected areas at a local level since the early 1990's. According to previous findings, such mechanisms help to create additional protected areas. The international research team has therefore set out to scale this idea up to the global level where not municipalities but nations are in charge of designating protected areas. They developed and compared three different design options:
An ecocentric model: where only protected area extent per country counts -- the bigger the protected area, the better;
A socio-ecological model: where protected areas and Human Development Index count, adding development justice to the previous model;
An anthropocentric model: where population density is also considered, as people benefit locally from protected areas.
The socio-ecological design was the one that proved to be the most efficient. The model provided the highest marginal incentives -- that is, the most additional money for protecting an additional percent of a country's area -- for countries that are the farthest from reaching the global conservation goals. The result surprised the researchers.
"While we developed the socio-ecological design with a fairness element in mind, believing that developing countries might be more easily convinced by a design that benefits them, we were surprised how well this particular design aligns with the global policy goals," says Nils Droste.
"It would most strongly incentivize additional conservation action where the global community is lacking it the most," he adds.
As the study was aimed at providing options, not prescriptions for policy makers, the study did not detail who should be paying or how large the fund should exactly be. Rather, it provides a yet unexplored option to develop a financial mechanism for biodiversity conservation akin to what the Green Climate Fund is for climate change.
Read more at Science Daily
After long negotiations, the international community has agreed to safeguard the global ecosystems and improve on the status of biodiversity. The global conservation goals for 2020, called the Aichi targets, are an ambitious hallmark. Yet, effective implementation is largely lacking. Biodiversity is still dwindling at rates only comparable to the last planetary mass extinction. Additional effort is required to reach the Aichi targets and even more so to halt biodiversity loss.
"Human well-being depends on ecological life support. Yet, we are constantly losing biodiversity and therefore the resilience of ecosystems. At the international level, there are political goals, but the implementation of conservation policies is a national task. There is no global financial mechanism that can help nations to reach their biodiversity targets," says lead author Nils Droste from Lund University, Sweden.
Brazil has successfully implemented Ecological Fiscal Transfer systems that compensate municipalities for hosting protected areas at a local level since the early 1990's. According to previous findings, such mechanisms help to create additional protected areas. The international research team has therefore set out to scale this idea up to the global level where not municipalities but nations are in charge of designating protected areas. They developed and compared three different design options:
An ecocentric model: where only protected area extent per country counts -- the bigger the protected area, the better;
A socio-ecological model: where protected areas and Human Development Index count, adding development justice to the previous model;
An anthropocentric model: where population density is also considered, as people benefit locally from protected areas.
The socio-ecological design was the one that proved to be the most efficient. The model provided the highest marginal incentives -- that is, the most additional money for protecting an additional percent of a country's area -- for countries that are the farthest from reaching the global conservation goals. The result surprised the researchers.
"While we developed the socio-ecological design with a fairness element in mind, believing that developing countries might be more easily convinced by a design that benefits them, we were surprised how well this particular design aligns with the global policy goals," says Nils Droste.
"It would most strongly incentivize additional conservation action where the global community is lacking it the most," he adds.
As the study was aimed at providing options, not prescriptions for policy makers, the study did not detail who should be paying or how large the fund should exactly be. Rather, it provides a yet unexplored option to develop a financial mechanism for biodiversity conservation akin to what the Green Climate Fund is for climate change.
Read more at Science Daily
New artifacts suggest people arrived in North America earlier than previously thought
Stone tools and other artifacts unearthed from an archeological dig at the Cooper's Ferry site in western Idaho suggest that people lived in the area 16,000 years ago, more than a thousand years earlier than scientists previously thought.
The artifacts would be considered among the earliest evidence of people in North America.
The findings, published today in Science, add weight to the hypothesis that initial human migration to the Americas followed a Pacific coastal route rather than through the opening of an inland ice-free corridor, said Loren Davis, a professor of anthropology at Oregon State University and the study's lead author.
"The Cooper's Ferry site is located along the Salmon River, which is a tributary of the larger Columbia River basin. Early peoples moving south along the Pacific coast would have encountered the Columbia River as the first place below the glaciers where they could easily walk and paddle in to North America," Davis said. "Essentially, the Columbia River corridor was the first off-ramp of a Pacific coast migration route.
"The timing and position of the Cooper's Ferry site is consistent with and most easily explained as the result of an early Pacific coastal migration."
Cooper's Ferry, located at the confluence of Rock Creek and the lower Salmon River, is known by the Nez Perce Tribe as an ancient village site named Nipéhe. Today the site is managed by the U.S. Bureau of Land Management.
Davis first began studying Cooper's Ferry as an archaeologist for the BLM in the 1990s. After joining the Oregon State faculty, he partnered with the BLM to establish a summer archaeological field school there, bringing undergraduate and graduate students from Oregon State and elsewhere for eight weeks each summer from 2009 to 2018 to help with the research.
The site includes two dig areas; the published findings are about artifacts found in area A. In the lower part of that area, researchers uncovered several hundred artifacts, including stone tools; charcoal; fire-cracked rock; and bone fragments likely from medium- to large-bodied animals, Davis said. They also found evidence of a fire hearth, a food processing station and other pits created as part of domestic activities at the site.
Over the last two summers, the team of students and researchers reached the lower layers of the site, which, as expected, contained some of the oldest artifacts uncovered, Davis said. He worked with a team of researchers at Oxford University, who were able to successfully radiocarbon date a number of the animal bone fragments.
The results showed many artifacts from the lowest layers are associated with dates in the range of 15,000 to 16,000 years old.
"Prior to getting these radiocarbon ages, the oldest things we'd found dated mostly in the 13,000-year range, and the earliest evidence of people in the Americas had been dated to just before 14,000 years old in a handful of other sites," Davis said. "When I first saw that the lower archaeological layer contained radiocarbon ages older than 14,000 years, I was stunned but skeptical and needed to see those numbers repeated over and over just to be sure they're right. So we ran more radiocarbon dates, and the lower layer consistently dated between 14,000-16,000 years old."
The dates from the oldest artifacts challenge the long-held "Clovis First" theory of early migration to the Americas, which suggested that people crossed from Siberia into North America and traveled down through an opening in the ice sheet near the present-day Dakotas. The ice-free corridor is hypothesized to have opened as early as 14,800 years ago, well after the date of the oldest artifacts found at Cooper's Ferry, Davis said.
"Now we have good evidence that people were in Idaho before that corridor opened," he said. "This evidence leads us to conclude that early peoples moved south of continental ice sheets along the Pacific coast."
Davis's team also found tooth fragments from an extinct form of horse known to have lived in North America at the end of the last glacial period. These tooth fragments, along with the radiocarbon dating, show that Cooper's Ferry is the oldest radiocarbon-dated site in North America that includes artifacts associated with the bones of extinct animals, Davis said.
The oldest artifacts uncovered at Cooper's Ferry also are very similar in form to older artifacts found in northeastern Asia, and particularly, Japan, Davis said. He is now collaborating with Japanese researchers to do further comparisons of artifacts from Japan, Russia and Cooper's Ferry. He is also awaiting carbon-dating information from artifacts from a second dig location at the Cooper's Ferry site.
Read more at Science Daily
The artifacts would be considered among the earliest evidence of people in North America.
The findings, published today in Science, add weight to the hypothesis that initial human migration to the Americas followed a Pacific coastal route rather than through the opening of an inland ice-free corridor, said Loren Davis, a professor of anthropology at Oregon State University and the study's lead author.
"The Cooper's Ferry site is located along the Salmon River, which is a tributary of the larger Columbia River basin. Early peoples moving south along the Pacific coast would have encountered the Columbia River as the first place below the glaciers where they could easily walk and paddle in to North America," Davis said. "Essentially, the Columbia River corridor was the first off-ramp of a Pacific coast migration route.
"The timing and position of the Cooper's Ferry site is consistent with and most easily explained as the result of an early Pacific coastal migration."
Cooper's Ferry, located at the confluence of Rock Creek and the lower Salmon River, is known by the Nez Perce Tribe as an ancient village site named Nipéhe. Today the site is managed by the U.S. Bureau of Land Management.
Davis first began studying Cooper's Ferry as an archaeologist for the BLM in the 1990s. After joining the Oregon State faculty, he partnered with the BLM to establish a summer archaeological field school there, bringing undergraduate and graduate students from Oregon State and elsewhere for eight weeks each summer from 2009 to 2018 to help with the research.
The site includes two dig areas; the published findings are about artifacts found in area A. In the lower part of that area, researchers uncovered several hundred artifacts, including stone tools; charcoal; fire-cracked rock; and bone fragments likely from medium- to large-bodied animals, Davis said. They also found evidence of a fire hearth, a food processing station and other pits created as part of domestic activities at the site.
Over the last two summers, the team of students and researchers reached the lower layers of the site, which, as expected, contained some of the oldest artifacts uncovered, Davis said. He worked with a team of researchers at Oxford University, who were able to successfully radiocarbon date a number of the animal bone fragments.
The results showed many artifacts from the lowest layers are associated with dates in the range of 15,000 to 16,000 years old.
"Prior to getting these radiocarbon ages, the oldest things we'd found dated mostly in the 13,000-year range, and the earliest evidence of people in the Americas had been dated to just before 14,000 years old in a handful of other sites," Davis said. "When I first saw that the lower archaeological layer contained radiocarbon ages older than 14,000 years, I was stunned but skeptical and needed to see those numbers repeated over and over just to be sure they're right. So we ran more radiocarbon dates, and the lower layer consistently dated between 14,000-16,000 years old."
The dates from the oldest artifacts challenge the long-held "Clovis First" theory of early migration to the Americas, which suggested that people crossed from Siberia into North America and traveled down through an opening in the ice sheet near the present-day Dakotas. The ice-free corridor is hypothesized to have opened as early as 14,800 years ago, well after the date of the oldest artifacts found at Cooper's Ferry, Davis said.
"Now we have good evidence that people were in Idaho before that corridor opened," he said. "This evidence leads us to conclude that early peoples moved south of continental ice sheets along the Pacific coast."
Davis's team also found tooth fragments from an extinct form of horse known to have lived in North America at the end of the last glacial period. These tooth fragments, along with the radiocarbon dating, show that Cooper's Ferry is the oldest radiocarbon-dated site in North America that includes artifacts associated with the bones of extinct animals, Davis said.
The oldest artifacts uncovered at Cooper's Ferry also are very similar in form to older artifacts found in northeastern Asia, and particularly, Japan, Davis said. He is now collaborating with Japanese researchers to do further comparisons of artifacts from Japan, Russia and Cooper's Ferry. He is also awaiting carbon-dating information from artifacts from a second dig location at the Cooper's Ferry site.
Read more at Science Daily
Evidence for past high-level sea rise
An international team of scientists, studying evidence preserved in speleothems in a coastal cave, illustrate that more than three million years ago -- a time in which the Earth was two to three degrees Celsius warmer than the pre-industrial era -- sea level was as much as 16 meters higher than the present day. Their findings represent significant implications for understanding and predicting the pace of current-day sea level rise amid a warming climate.
The scientists, including Professor Yemane Asmerom and Sr. Research Scientist Victor Polyak from The University of New Mexico, the University of South Florida, Universitat de les Illes Balears and Columbia University, published their findings in today's edition of the journal Nature. The analysis of deposits from Artà Cave on the island of Mallorca in the western Mediterranean Sea produced sea levels that serve as a target for future studies of ice sheet stability, ice sheet model calibrations and projections of future sea level rise, the scientists said.
Sea level rises as a result of melting ice sheets, such as those that cover Greenland and Antarctica. However, how much and how fast sea level will rise during warming is a question scientists have worked to answer. Reconstructing ice sheet and sea-level changes during past periods when climate was naturally warmer than today, provides an Earth's scale laboratory experiment to study this question according to USF Ph.D. student Oana Dumitru, the lead author, who did much of her dating work at UNM under the guidance of Asmerom and Polyak.
"Constraining models for sea level rise due to increased warming critically depends on actual measurements of past sea level," said Polyak. "This study provides very robust measurements of sea level heights during the Pliocene."
"We can use knowledge gained from past warm periods to tune ice sheet models that are then used to predict future ice sheet response to current global warming," said USF Department of Geosciences Professor Bogdan Onac.
The project focused on cave deposits known as phreatic overgrowths on speleothems. The deposits form in coastal caves at the interface between brackish water and cave air each time the ancient caves were flooded by rising sea levels. In Artà Cave, which is located within 100 meters of the coast, the water table is -- and was in the past -- coincident with sea level, says Professor Joan J. Fornós of Universitat de les Illes Balears.
The scientists discovered, analyzed, and interpreted six of the geologic formations found at elevations of 22.5 to 32 meters above present sea level. Careful sampling and laboratory analyses of 70 samples resulted in ages ranging from 4.4 to 3.3 million years old BP (Before Present), indicating that the cave deposits formed during the Pliocene epoch. The ages were determined using uranium-lead radiometric dating in UNM's Radiogenic Isotope Laboratory.
"This was a unique convergence between an ideally-suited natural setting worked out by the team of cave scientists and the technical developments we have achieved over the years in our lab at The University of New Mexico," said Asmerom. "Judicious investments in instrumentation and techniques result in these kinds of high-impact dividends."
"Sea level changes at Artà Cave can be caused by the melting and growing of ice sheets or by uplift or subsidence of the island itself," said Columbia University Assistant Professor Jacky Austermann, a member of the research team. She used numerical and statistical models to carefully analyze how much uplift or subsidence might have happened since the Pliocene and subtracted this from the elevation of the formations they investigated.
One key interval of particular interest during the Pliocene is the mid Piacenzian Warm Period -- some 3.264 to 3.025 million years ago -- when temperatures were 2 to 3º Celsius higher than pre-industrial levels. "The interval also marks the last time the Earth's atmospheric CO2 was as high as today, providing important clues about what the future holds in the face of current anthropogenic warming," Onac says.
This study found that during this period, global mean sea level was as high as 16.2 meters (with an uncertainty range of 5.6 to 19.2 meters) above present. This means that even if atmospheric CO2 stabilizes around current levels, the global mean sea level would still likely rise at least that high, if not higher, the scientists concluded. In fact, it is likely to rise higher because of the increase in the volume of the oceans due to rising temperature.
"Considering the present-day melt patterns, this extent of sea level rise would most likely be caused by a collapse of both Greenland and the West Antarctic ice sheets," Dumitru said.
Read more at Science Daily
The scientists, including Professor Yemane Asmerom and Sr. Research Scientist Victor Polyak from The University of New Mexico, the University of South Florida, Universitat de les Illes Balears and Columbia University, published their findings in today's edition of the journal Nature. The analysis of deposits from Artà Cave on the island of Mallorca in the western Mediterranean Sea produced sea levels that serve as a target for future studies of ice sheet stability, ice sheet model calibrations and projections of future sea level rise, the scientists said.
Sea level rises as a result of melting ice sheets, such as those that cover Greenland and Antarctica. However, how much and how fast sea level will rise during warming is a question scientists have worked to answer. Reconstructing ice sheet and sea-level changes during past periods when climate was naturally warmer than today, provides an Earth's scale laboratory experiment to study this question according to USF Ph.D. student Oana Dumitru, the lead author, who did much of her dating work at UNM under the guidance of Asmerom and Polyak.
"Constraining models for sea level rise due to increased warming critically depends on actual measurements of past sea level," said Polyak. "This study provides very robust measurements of sea level heights during the Pliocene."
"We can use knowledge gained from past warm periods to tune ice sheet models that are then used to predict future ice sheet response to current global warming," said USF Department of Geosciences Professor Bogdan Onac.
The project focused on cave deposits known as phreatic overgrowths on speleothems. The deposits form in coastal caves at the interface between brackish water and cave air each time the ancient caves were flooded by rising sea levels. In Artà Cave, which is located within 100 meters of the coast, the water table is -- and was in the past -- coincident with sea level, says Professor Joan J. Fornós of Universitat de les Illes Balears.
The scientists discovered, analyzed, and interpreted six of the geologic formations found at elevations of 22.5 to 32 meters above present sea level. Careful sampling and laboratory analyses of 70 samples resulted in ages ranging from 4.4 to 3.3 million years old BP (Before Present), indicating that the cave deposits formed during the Pliocene epoch. The ages were determined using uranium-lead radiometric dating in UNM's Radiogenic Isotope Laboratory.
"This was a unique convergence between an ideally-suited natural setting worked out by the team of cave scientists and the technical developments we have achieved over the years in our lab at The University of New Mexico," said Asmerom. "Judicious investments in instrumentation and techniques result in these kinds of high-impact dividends."
"Sea level changes at Artà Cave can be caused by the melting and growing of ice sheets or by uplift or subsidence of the island itself," said Columbia University Assistant Professor Jacky Austermann, a member of the research team. She used numerical and statistical models to carefully analyze how much uplift or subsidence might have happened since the Pliocene and subtracted this from the elevation of the formations they investigated.
One key interval of particular interest during the Pliocene is the mid Piacenzian Warm Period -- some 3.264 to 3.025 million years ago -- when temperatures were 2 to 3º Celsius higher than pre-industrial levels. "The interval also marks the last time the Earth's atmospheric CO2 was as high as today, providing important clues about what the future holds in the face of current anthropogenic warming," Onac says.
This study found that during this period, global mean sea level was as high as 16.2 meters (with an uncertainty range of 5.6 to 19.2 meters) above present. This means that even if atmospheric CO2 stabilizes around current levels, the global mean sea level would still likely rise at least that high, if not higher, the scientists concluded. In fact, it is likely to rise higher because of the increase in the volume of the oceans due to rising temperature.
"Considering the present-day melt patterns, this extent of sea level rise would most likely be caused by a collapse of both Greenland and the West Antarctic ice sheets," Dumitru said.
Read more at Science Daily
How bacteria behind hospital infections block out antibiotics
Drug-resistant bacteria responsible for deadly hospital-acquired infections shut out antibiotics by closing tiny doors in their cell walls.
The new finding by researchers at Imperial College London could allow researchers to design new drugs that 'pick the locks' of these closed doors and allow antibiotics into bacterial cells. The result is published today in Nature Communications.
The bacterium Klebsiella pneumoniae causes infections in the lungs, blood and wounds of those in hospitals, and patients that have compromised immune systems are especially vulnerable. More than 20,000 K. pneumoniae infections were recorded in UK hospitals in the past year.
Like many bacteria, K. pneumoniae is becoming increasingly resistant to antibiotics, particularly a family of drugs called Carbapenems. Carbapenems are used as antibiotics in hospitals when others have failed or are ineffective.
Therefore, rising resistance to Carbapenems could dramatically affect our ability to cure infections. For this reason, Carbapenem-resistant K. pneumoniae and are classified as 'critical' World Health Organization Priority 1 organisms.
Now, the team from Imperial has discovered one mechanism by which K. pneumoniae is able to resist Carbapenems. Antibiotics usually enter the K. pneumoniae bacteria through surface doorways known as pores. The team investigated the structure of the pores and showed that by shutting these doorways K. pneumoniae becomes resistant to multiple drugs, since antibiotics cannot enter and kill them.
First author, Dr Joshua Wong, from the Department of Life Sciences at Imperial, said: "The prevalence of antibiotic resistance is increasing, so we are becoming more and more reliant on drugs like Carbapenems that work against a wide range of bacteria.
"But now with important bacteria like K. pneumoniae gaining resistance to Carbapenems it's important we understand how they are able to achieve this. Our new study provides vital insights that could allow new strategies and drugs to be designed."
The team compared the structures of K. pneumoniae bacteria that were resistant to Carbapenems to those that weren't, and found the resistant bacteria had modified or absent versions of a protein that creates pores in the cell wall. Resistant bacteria have much smaller pores, blocking the drug from entering.
The closed doors aren't all good news for bacteria. They also mean that the bacteria can take in fewer nutrients, and tests in mice showed that the bacteria grow slower as a result.
However, the advantage in terms of avoiding antibiotics outweighed the negative impact of slower growth for the bacteria, allowing them to maintain a high level of infection.
The project was conducted in close collaboration with Dr Konstantinos Beis from the Department of Life Sciences, who is based at the Research Complex at Harwell in Oxfordshire.
The team was led by Professor Gad Frankel, from the Department of Life Sciences at Imperial, who said: "The modification the bacteria use to avoid antibiotics is difficult to get around. Any drugs to counteract this defence mechanism would likely also get blocked out by the closed doors.
"However, we hope that it will be possible to design drugs that can pick the lock of the door, and our data provides information to help scientists and pharmaceutical companies make these new agents a reality."
As resistant bacteria are weaker, these results suggest that the pressure posed by the extensive use of Carbapenems in hospital settings is a major driver in the spread of these superbugs. The study provides a direct scientific basis for the implementation of restrictive prescribing policies that would minimise the use of broad-spectrum agents such as Carbapenems.
Read more at Science Daily
The new finding by researchers at Imperial College London could allow researchers to design new drugs that 'pick the locks' of these closed doors and allow antibiotics into bacterial cells. The result is published today in Nature Communications.
The bacterium Klebsiella pneumoniae causes infections in the lungs, blood and wounds of those in hospitals, and patients that have compromised immune systems are especially vulnerable. More than 20,000 K. pneumoniae infections were recorded in UK hospitals in the past year.
Like many bacteria, K. pneumoniae is becoming increasingly resistant to antibiotics, particularly a family of drugs called Carbapenems. Carbapenems are used as antibiotics in hospitals when others have failed or are ineffective.
Therefore, rising resistance to Carbapenems could dramatically affect our ability to cure infections. For this reason, Carbapenem-resistant K. pneumoniae and are classified as 'critical' World Health Organization Priority 1 organisms.
Now, the team from Imperial has discovered one mechanism by which K. pneumoniae is able to resist Carbapenems. Antibiotics usually enter the K. pneumoniae bacteria through surface doorways known as pores. The team investigated the structure of the pores and showed that by shutting these doorways K. pneumoniae becomes resistant to multiple drugs, since antibiotics cannot enter and kill them.
First author, Dr Joshua Wong, from the Department of Life Sciences at Imperial, said: "The prevalence of antibiotic resistance is increasing, so we are becoming more and more reliant on drugs like Carbapenems that work against a wide range of bacteria.
"But now with important bacteria like K. pneumoniae gaining resistance to Carbapenems it's important we understand how they are able to achieve this. Our new study provides vital insights that could allow new strategies and drugs to be designed."
The team compared the structures of K. pneumoniae bacteria that were resistant to Carbapenems to those that weren't, and found the resistant bacteria had modified or absent versions of a protein that creates pores in the cell wall. Resistant bacteria have much smaller pores, blocking the drug from entering.
The closed doors aren't all good news for bacteria. They also mean that the bacteria can take in fewer nutrients, and tests in mice showed that the bacteria grow slower as a result.
However, the advantage in terms of avoiding antibiotics outweighed the negative impact of slower growth for the bacteria, allowing them to maintain a high level of infection.
The project was conducted in close collaboration with Dr Konstantinos Beis from the Department of Life Sciences, who is based at the Research Complex at Harwell in Oxfordshire.
The team was led by Professor Gad Frankel, from the Department of Life Sciences at Imperial, who said: "The modification the bacteria use to avoid antibiotics is difficult to get around. Any drugs to counteract this defence mechanism would likely also get blocked out by the closed doors.
"However, we hope that it will be possible to design drugs that can pick the lock of the door, and our data provides information to help scientists and pharmaceutical companies make these new agents a reality."
As resistant bacteria are weaker, these results suggest that the pressure posed by the extensive use of Carbapenems in hospital settings is a major driver in the spread of these superbugs. The study provides a direct scientific basis for the implementation of restrictive prescribing policies that would minimise the use of broad-spectrum agents such as Carbapenems.
Read more at Science Daily
Sep 1, 2019
Aspirin should not be recommended for healthy people over 70
Low-dose aspirin does not prolong disability-free survival of healthy people over 70, even in those at the highest risk of cardiovascular disease. The late breaking results of the ASPREE trial are presented today at ESC Congress 2019 together with the World Congress of Cardiology.
On behalf of the ASPREE Investigators, Professor Christopher Reid of Curtin University, Perth, Australia said: "An ever-increasing number of people reach the age of 70 without overt cardiovascular disease (CVD). This analysis suggests that improved risk prediction methods are needed to identify those who could benefit from daily low-dose aspirin."
European guidelines on the prevention of CVD do not recommend aspirin for individuals free from CVD due to the increased risk of major bleeding. This advice was subsequently supported by results in moderate risk patients (ARRIVE), diabetic patients (ASCEND), and in people over 70 (ASPREE) which demonstrated that modest reductions in CVD risk were outweighed by the increased bleeding hazard.
The primary finding from the ASPREE randomised trial was that in people aged 70 years or over with no known CVD, there was no effect of 100 mg of daily aspirin on the composite primary endpoint of disability-free survival (defined as those not reaching a primary endpoint of dementia or persistent physical disability or death). The primary endpoint was chosen to reflect the reasons for prescribing a preventive drug in an otherwise healthy elderly population.
This analysis examined whether the results for the primary endpoint of disability-free survival might vary by the baseline level of CVD risk. Analyses were also conducted for the secondary endpoints of all-cause mortality, major haemorrhage, and prevention of CVD (defined as fatal coronary heart disease, nonfatal myocardial infarction, fatal or nonfatal stroke, or hospitalisation for heart failure).
The investigators calculated ten-year CVD risk probabilities at baseline for the 19,114 ASPREE participants using the Framingham score (up to 75 years) and the atherosclerotic cardiovascular disease (ASCVD) pooled cohort risk equations (up to 79 years) and divided them into thirds. As there are no CVD risk scores available beyond the age ranges specified in the equations, they also classified participants according to the presence of 0 to 1, 2 to 3, or more than 3 CVD risk factors. Overall rates of disability-free survival, mortality, major bleeding and CVD were examined for each risk group and outcomes were compared for those treated with aspirin or placebo.
For participants in the lowest third of CVD risk, by both Framingham and ASCVD scores, there was no disability-free survival or cardiovascular benefit from aspirin. This group also had the highest likelihood of bleeding.
In contrast, those in the highest third of CVD risk, by both Framingham and ASCVD scores, had significantly lower CVD event rates on aspirin with similar rates of bleeding. Hazard ratios for CVD reduction with aspirin version placebo were 0.72 (95% confidence interval [CI] 0.54-0.95) for the group classified as high risk by the Framingham score and 0.75 (95% CI 0.58-0.97) for those defined as high risk by the ASCVD equations.
However, this reduction in CVD did not translate to a significantly improved disability-free survival. Hazard ratios for disability-free survival with aspirin versus placebo were 0.86 (95% CI 0.62-1.20) for the group designated high risk by the Framingham score and 0.89 (95% CI 0.62-1.28) for those considered high risk by the ASCVD equations.
Prof Reid said: "The findings emphasise that the risk-benefit trade-off for aspirin use in healthy older men and women varies across levels of cardiovascular risk. It also indicates that the reduction in CVD events in the highest risk groups using current stratification methods does not identify individuals in whom this advantage translates into longer disability-free survival."
New ways to identify groups at increased CVD risk, beyond the use of conventional risk factors and current prediction models, will be investigated in the ASPREE longitudinal follow-up study. Genetic and biomarker information will be included from the ASPREE biobank.
Read more at Science Daily
On behalf of the ASPREE Investigators, Professor Christopher Reid of Curtin University, Perth, Australia said: "An ever-increasing number of people reach the age of 70 without overt cardiovascular disease (CVD). This analysis suggests that improved risk prediction methods are needed to identify those who could benefit from daily low-dose aspirin."
European guidelines on the prevention of CVD do not recommend aspirin for individuals free from CVD due to the increased risk of major bleeding. This advice was subsequently supported by results in moderate risk patients (ARRIVE), diabetic patients (ASCEND), and in people over 70 (ASPREE) which demonstrated that modest reductions in CVD risk were outweighed by the increased bleeding hazard.
The primary finding from the ASPREE randomised trial was that in people aged 70 years or over with no known CVD, there was no effect of 100 mg of daily aspirin on the composite primary endpoint of disability-free survival (defined as those not reaching a primary endpoint of dementia or persistent physical disability or death). The primary endpoint was chosen to reflect the reasons for prescribing a preventive drug in an otherwise healthy elderly population.
This analysis examined whether the results for the primary endpoint of disability-free survival might vary by the baseline level of CVD risk. Analyses were also conducted for the secondary endpoints of all-cause mortality, major haemorrhage, and prevention of CVD (defined as fatal coronary heart disease, nonfatal myocardial infarction, fatal or nonfatal stroke, or hospitalisation for heart failure).
The investigators calculated ten-year CVD risk probabilities at baseline for the 19,114 ASPREE participants using the Framingham score (up to 75 years) and the atherosclerotic cardiovascular disease (ASCVD) pooled cohort risk equations (up to 79 years) and divided them into thirds. As there are no CVD risk scores available beyond the age ranges specified in the equations, they also classified participants according to the presence of 0 to 1, 2 to 3, or more than 3 CVD risk factors. Overall rates of disability-free survival, mortality, major bleeding and CVD were examined for each risk group and outcomes were compared for those treated with aspirin or placebo.
For participants in the lowest third of CVD risk, by both Framingham and ASCVD scores, there was no disability-free survival or cardiovascular benefit from aspirin. This group also had the highest likelihood of bleeding.
In contrast, those in the highest third of CVD risk, by both Framingham and ASCVD scores, had significantly lower CVD event rates on aspirin with similar rates of bleeding. Hazard ratios for CVD reduction with aspirin version placebo were 0.72 (95% confidence interval [CI] 0.54-0.95) for the group classified as high risk by the Framingham score and 0.75 (95% CI 0.58-0.97) for those defined as high risk by the ASCVD equations.
However, this reduction in CVD did not translate to a significantly improved disability-free survival. Hazard ratios for disability-free survival with aspirin versus placebo were 0.86 (95% CI 0.62-1.20) for the group designated high risk by the Framingham score and 0.89 (95% CI 0.62-1.28) for those considered high risk by the ASCVD equations.
Prof Reid said: "The findings emphasise that the risk-benefit trade-off for aspirin use in healthy older men and women varies across levels of cardiovascular risk. It also indicates that the reduction in CVD events in the highest risk groups using current stratification methods does not identify individuals in whom this advantage translates into longer disability-free survival."
New ways to identify groups at increased CVD risk, beyond the use of conventional risk factors and current prediction models, will be investigated in the ASPREE longitudinal follow-up study. Genetic and biomarker information will be included from the ASPREE biobank.
Read more at Science Daily
Suggested move to plant-based diets risks worsening brain health nutrient deficiency
The momentum behind a move to plant-based and vegan diets for the good of the planet is commendable, but risks worsening an already low intake of an essential nutrient involved in brain health, warns a nutritionist in the online journal BMJ Nutrition, Prevention & Health.
To make matters worse, the UK government has failed to recommend or monitor dietary levels of this nutrient -- choline -- found predominantly in animal foods, says Dr Emma Derbyshire, of Nutritional Insight, a consultancy specialising in nutrition and biomedical science.
Choline is an essential dietary nutrient, but the amount produced by the liver is not enough to meet the requirements of the human body.
Choline is critical to brain health, particularly during fetal development. It also influences liver function, with shortfalls linked to irregularities in blood fat metabolism as well as excess free radical cellular damage, writes Dr Derbyshire.
The primary sources of dietary choline are found in beef, eggs, dairy products, fish, and chicken, with much lower levels found in nuts, beans, and cruciferous vegetables, such as broccoli.
In 1998, recognising the importance of choline, the US Institute of Medicine recommended minimum daily intakes. These range from 425 mg/day for women to 550 mg/day for men, and 450 mg/day and 550 mg/day for pregnant and breastfeeding women, respectively, because of the critical role the nutrient has in fetal development.
In 2016, the European Food Safety Authority published similar daily requirements. Yet national dietary surveys in North America, Australia, and Europe show that habitual choline intake, on average, falls short of these recommendations.
"This is....concerning given that current trends appear to be towards meat reduction and plant-based diets," says Dr Derbyshire.
She commends the first report (EAT-Lancet) to compile a healthy food plan based on promoting environmental sustainability, but suggests that the restricted intakes of whole milk, eggs and animal protein it recommends could affect choline intake.
And she is at a loss to understand why choline does not feature in UK dietary guidance or national population monitoring data.
"Given the important physiological roles of choline and authorisation of certain health claims, it is questionable why choline has been overlooked for so long in the UK," she writes. "Choline is presently excluded from UK food composition databases, major dietary surveys, and dietary guidelines," she adds.
It may be time for the UK government's independent Scientific Advisory Committee on Nutrition to reverse this, she suggests, particularly given the mounting evidence on the importance of choline to human health and growing concerns about the sustainability of the planet's food production.
"More needs to be done to educate healthcare professionals and consumers about the importance of a choline-rich diet, and how to achieve this," she writes.
Read more at Science Daily
To make matters worse, the UK government has failed to recommend or monitor dietary levels of this nutrient -- choline -- found predominantly in animal foods, says Dr Emma Derbyshire, of Nutritional Insight, a consultancy specialising in nutrition and biomedical science.
Choline is an essential dietary nutrient, but the amount produced by the liver is not enough to meet the requirements of the human body.
Choline is critical to brain health, particularly during fetal development. It also influences liver function, with shortfalls linked to irregularities in blood fat metabolism as well as excess free radical cellular damage, writes Dr Derbyshire.
The primary sources of dietary choline are found in beef, eggs, dairy products, fish, and chicken, with much lower levels found in nuts, beans, and cruciferous vegetables, such as broccoli.
In 1998, recognising the importance of choline, the US Institute of Medicine recommended minimum daily intakes. These range from 425 mg/day for women to 550 mg/day for men, and 450 mg/day and 550 mg/day for pregnant and breastfeeding women, respectively, because of the critical role the nutrient has in fetal development.
In 2016, the European Food Safety Authority published similar daily requirements. Yet national dietary surveys in North America, Australia, and Europe show that habitual choline intake, on average, falls short of these recommendations.
"This is....concerning given that current trends appear to be towards meat reduction and plant-based diets," says Dr Derbyshire.
She commends the first report (EAT-Lancet) to compile a healthy food plan based on promoting environmental sustainability, but suggests that the restricted intakes of whole milk, eggs and animal protein it recommends could affect choline intake.
And she is at a loss to understand why choline does not feature in UK dietary guidance or national population monitoring data.
"Given the important physiological roles of choline and authorisation of certain health claims, it is questionable why choline has been overlooked for so long in the UK," she writes. "Choline is presently excluded from UK food composition databases, major dietary surveys, and dietary guidelines," she adds.
It may be time for the UK government's independent Scientific Advisory Committee on Nutrition to reverse this, she suggests, particularly given the mounting evidence on the importance of choline to human health and growing concerns about the sustainability of the planet's food production.
"More needs to be done to educate healthcare professionals and consumers about the importance of a choline-rich diet, and how to achieve this," she writes.
Read more at Science Daily
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