Tumor suppressor gene linked to stem cells, cancer biologists report

Just as archeologists try to decipher ancient tablets to discern their meaning, UT Southwestern Medical Center cancer biologists are working to decode the purpose of an ancient gene considered one of the most important in cancer research.The p53 gene appears to be involved in signaling other cells instrumental in stopping tumor development. But the p53 gene predates cancer, so scientists are uncertain what its original function is.In trying to unravel the mystery, Dr. John Abrams, Professor of Cell Biology at UT Southwestern, and his team made a crucial new discovery — tying the p53 gene to stem cells. Specifically, his lab found that when cellular damage is present, the gene is hyperactive in stem cells, but not in other cells. The findings suggest p53’s tumor suppression ability may have evolved from its more ancient ability to regulate stem cell growth.”The discovery was that only the stem cells light up. None of the others do. The exciting implication is that we are able to understand the function of p53 in stem cells,” said Dr. Abrams, Chair of the Genetics and Development program in UT Southwestern’s Graduate School of Biomedical Sciences. “We may, in fact, have some important answers for how p53 suppresses tumors.”The findings appear online in the journal eLife, a joint initiative of the Howard Hughes Medical Institute, the Max Planck Society, and the Wellcome Trust.p53 is one of the hardest working and most effective allies in the fight against cancer, said Dr. Abrams. …

Read more

Ancient sea creatures filtered food like modern whales

Ancient, giant marine animals used bizarre facial appendages to filter food from the ocean, according to new fossils discovered in northern Greenland. The new study, led by the University of Bristol and published today in Nature, describes how the strange species, called Tamisiocaris, used these huge, specialized appendages to filter plankton, similar to the way modern blue whales feed today.The animals lived 520 million years ago during the Early Cambrian, a period known as the ‘Cambrian Explosion’ in which all the major animal groups and complex ecosystems suddenly appeared. Tamisiocaris belongs to a group of animals called anomalocarids, a type of early arthropod that included the largest and some of the most iconic animals of the Cambrian period. They swam using flaps down either side of the body and had large appendages in front of their mouths that they most likely used to capture larger prey, such as trilobites.However, the newly discovered fossils show that those predators also evolved into suspension feeders, their grasping appendages morphing into a filtering apparatus that could be swept like a net through the water, trapping small crustaceans and other organisms as small as half a millimetre in size.The evolutionary trend that led from large, apex predators to gentle, suspension-feeding giants during the highly productive Cambrian period is one that has also taken place several other times throughout Earth’s history, according to lead author Dr Jakob Vinther, a lecturer in macroevolution at the University of Bristol.Dr Vinther said: “These primitive arthropods were, ecologically speaking, the sharks and whales of the Cambrian era. In both sharks and whales, some species evolved into suspension feeders and became gigantic, slow-moving animals that in turn fed on the smallest animals in the water.”In order to fully understand how the Tamisiocaris might have fed, the researchers created a 3D computer animation of the feeding appendage to explore the range of movements it could have made.”Tamisiocaris would have been a sweep net feeder, collecting particles in the fine mesh formed when it curled its appendage up against its mouth,” said Dr Martin Stein of the University of Copenhagen, who created the computer animation. “This is a rare instance when you can actually say something concrete about the feeding ecology of these types of ancient creatures with some confidence.”The discovery also helps highlight just how productive the Cambrian period was, showing how vastly different species of anomalocaridids evolved at that time, and provides further insight into the ecosystems that existed hundreds of millions of years ago.”The fact that large, free-swimming suspension feeders roamed the oceans tells us a lot about the ecosystem,” Dr Vinther said. “Feeding on the smallest particles by filtering them out of the water while actively swimming around requires a lot of energy — and therefore lots of food.”Tamisiocaris is one of many recent discoveries of remarkably diverse anomalocarids found in rocks aged 520 to 480 million years old. “We once thought that anomalocarids were a weird, failed experiment,” said co-author Dr Nicholas Longrich at the University of Bath. “Now we’re finding that they pulled off a major evolutionary explosion, doing everything from acting as top predators to feeding on tiny plankton.”The Tamisiocaris fossils were discovered during a series of recent expeditions led by co-author David Harper, a professor at Durham University. “The expeditions have unearthed a real treasure trove of new fossils in one of the remotest parts of the planet, and there are many new fossil animals still waiting to be described,” he said. …

Read more

New insights into ancient Pacific settlers’ diet: Diet based on foraging, not horticulture

Researchers from New Zealand’s University of Otago studying 3000-year-old skeletons from the oldest known cemetery in the Pacific Islands are casting new light on the diet and lives of the enigmatic Lapita people, the likely ancestors of Polynesians.Their results — obtained from analysing stable isotope ratios of three elements in the bone collagen of 49 adults buried at the Teouma archaeological site on Vanuatu’s Efate Island — suggest that its early Lapita settlers ate reef fish, marine turtles, fruit bats, free-range pigs and chickens, rather than primarily relying on growing crops for human food and animal fodder.The findings are newly published in the journal PLOS ONE. Study lead author Dr Rebecca Kinaston and colleague Associate Professor Hallie Buckley at the Department of Anatomy carried out the research in collaboration with the Vanuatu National Museum and researchers from the University of Marseilles and CNRS (UMR 7269 and UMR 7041) in France and The Australian National University, Canberra.Dr Kinaston says the study is the most detailed analysis of Lapita diet ever undertaken and provides intriguing insights into the socio-cultural elements of their society.”It was a unique opportunity to assess the lifeways of a colonising population on a tropical Pacific island,” she says.The researchers analysed the isotopic ratios of carbon, nitrogen and sulphur in adult human bone collagen and compared these with ratios in ancient and modern plants and animals from the location, which provided a comprehensive dietary baseline.”Examining these ratios gave us direct evidence of the broad make-up of these adults’ diets over the 10-20 years before they died, which helps clear up the long-running debate about how the Lapita settlers sustained themselves during the early phases of colonising each island during their eastward drive across the Pacific.”Dr Kinaston says it appears that the new colonists, rather than relying mainly on a “transported landscape” of the crop plants and domesticated animals they brought with them, were practicing a mixed subsistence strategy.”The dietary pattern we found suggests that in addition to eating pigs and chickens, settlers were also foraging for a variety of marine food and consuming wild animals — especially fruit bats — and that whatever horticultural food they produced was not heavily relied on,” she says.Isotopic analysis of the ancient pig bones found at the site also suggests that they were free-ranging rather than penned and given fodder from harvested crops.Study of the human bones revealed a sex difference in diet compositions, showing that Lapita men had more varied diets and greater access to protein from sources such as tortoises, pigs and chicken than women did.”This may have resulted from unequal food distribution, suggesting that males may have been considered of higher status in Lapita society and treated preferentially,” Dr Kinaston says.Story Source:The above story is based on materials provided by University of Otago. Note: Materials may be edited for content and length.

Read more

‘Steak-knife’ teeth reveal ecology of oldest land predators

The first top predators to walk on land were not afraid to bite off more than they could chew, a University of Toronto Mississauga study has found.Graduate student and lead author Kirstin Brink along with Professor Robert Reisz from U of T Mississauga’s Department of Biology suggest that Dimetrodon, a carnivore that walked on land between 298 million and 272 million years ago, was the first terrestrial vertebrate to develop serrated ziphodont teeth.According to the study published in Nature Communications, ziphodont teeth, with their serrated edges, produced a more-efficient bite and would have allowed Dimetrodon to eat prey much larger than itself.While most meat-eating dinosaurs possessed ziphodont teeth, fossil evidence suggests serrated teeth first evolved in Dimetrodon some 40 million years earlier than theropod dinosaurs.”Technologies such as scanning electron microscope (SEM) and histology allowed us to examine these teeth in detail to reveal previously unknown patterns in the evolutionary history of Dimetrodon,” Brink said.The four-meter-long Dimetrodon was the top of the terrestrial food chain in the Early Permian Period and is considered to be the forerunner of mammals.According to Brink and Reisz’s research, Dimetrodon had a diversity of previously unknown tooth structures and were also the first terrestrial vertebrate to develop cusps — teeth with raised points on the crown, which are dominant in mammals.The study also suggests ziphodont teeth were confined to later species of Dimetrodon, indicating a gradual change in feeding habits.”This research is an important step in reconstructing the structure of ancient complex communities,” Reisz said.”Teeth tell us a lot more about the ecology of animals than just looking at the skeleton.””We already know from fossil evidence which animals existed at that time but now with this type of research we are starting to piece together how the members of these communities interacted.”Brink and Reisz studied the changes in Dimetrodon teeth across 25 million years of evolution.The analysis indicated the changes in tooth structure occurred in the absence of any significant evolution in skull morphology. This, Brink and Reisz suggest, indicates a change in feeding style and trophic interactions.”The steak knife configuration of these teeth and the architecture of the skull suggest Dimetrodon was able to grab and rip and dismember large prey,” Reisz said.”Teeth fossils have attracted a lot of attention in dinosaurs but much less is known about the animals that lived during this first chapter in terrestrial evolution.”Story Source:The above story is based on materials provided by University of Toronto. Note: Materials may be edited for content and length.

Read more

Computer literate again! High tea and good bye to a beautiful mesothelioma warrior and dear friend.

Hurrah! After 3 weeks of putting up with our ancient computer that failed recently due to an electrical storm we have bought a new computer and Keith set it up last night. So much quicker for everything. For those that are MAC freaks I hate to disappoint you – we have another PC!Last Saturday 1 February 2014 was the inaugural Ban Asbestos Conference to be held in Pakistan thanks to the Syed Fareed Ahmed Memorial Mesothelioma General Hospital Foundation and in particular Syed Mezab Ahmed and his father who bravely took on the cause/case after their uncle/brother died of tongue cancer caused by exposure to asbestos while working in Pakistan. It is a credit to both of them holding this conference and showing much needed awareness and education. …

Read more

Mesothelioma Alternative Therapy – What Are Your Options?

Quite a number of patients afflicted with asbestos related diseases such as asbestosis and mesothelioma now-a days use different types of complimentary and alternative therapies in addition to conventional therapies like surgery and drugs.These alternative therapies are used by patients coping with asbestos related disease as a form of pain management, to improve general health, and also to provide symptomatic relief.Although these treatments do not offer a cure, they certainly help you to live more comfortable lives by providing relief from pain and stress.The most commonly used alternative therapies include the following:1} AcupunctureThis is one of the commonest forms of available alternative therapies today, and there are a lot of insurance companies offering coverage for this type of treatment. Acupuncture involves the …

Read more

Ancient DNA unravels Europe’s genetic diversity

Oct. 10, 2013 — Ancient DNA recovered from a time series of skeletons in Germany spanning 4,000 years of prehistory has been used to reconstruct the first detailed genetic history of modern-day Europeans.The study, published today in Science, reveals dramatic population changes with waves of prehistoric migration, not only from the accepted path via the Near East, but also from Western and Eastern Europe.The research was a collaboration between the Australian Centre for Ancient DNA (ACAD), at the University of Adelaide, researchers from the University of Mainz, the State Heritage Museum in Halle (Germany), and National Geographic Society’s Genographic Project. The teams used mitochondrial DNA (maternally inherited DNA) extracted from bone and teeth samples from 364 prehistoric human skeletons ‒ ten times more than previous ancient DNA studies.”This is the largest and most detailed genetic time series of Europe yet created, allowing us to establish a complete genetic chronology,” says joint-lead author Dr Wolfgang Haak of ACAD. “Focussing on this small but highly important geographic region meant we could generate a gapless record, and directly observe genetic changes in ‘real-time’ from 7,500 to 3,500 years ago, from the earliest farmers to the early Bronze Age.””Our study shows that a simple mix of indigenous hunter-gatherers and the incoming Near Eastern farmers cannot explain the modern-day diversity alone,” says joint-lead author Guido Brandt, PhD candidate at the University of Mainz. “The genetic results are much more complex than that. Instead, we found that two particular cultures at the brink of the Bronze Age 4,200 years ago had a marked role in the formation of Central Europe’s genetic makeup.”Professor Kurt Alt (University of Mainz) says: “What is intriguing is that the genetic signals can be directly compared with the changes in material culture seen in the archaeological record. It is fascinating to see genetic changes when certain cultures expanded vastly, clearly revealing interactions across very large distances.” These included migrations from both Western and Eastern Europe towards the end of the Stone Age, through expanding cultures such as the Bell Beaker and the Corded Ware (named after their pots).”This transect through time has produced a wealth of information about the genetic history of modern Europeans,” says ACAD Director Professor Alan Cooper. “There was a period of stasis after farming became established and suitable areas were settled, and then sudden turnovers during less stable times or when economic factors changed, such as the increasing importance of metal ores and secondary farming products. While the genetic signal of the first farming populations becomes increasingly diluted over time, we see the original hunter-gatherers make a surprising comeback.”Dr Haak says: “None of the dynamic changes we observed could have been inferred from modern-day genetic data alone, highlighting the potential power of combining ancient DNA studies with archaeology to reconstruct human evolutionary history.” The international team has been working closely on the genetic prehistory of Europeans for the past 7-8 years and is currently applying powerful new technologies to generate genomic data from the specimens.

Read more

Darwin’s dilemma resolved: Evolution’s ‘big bang’ explained by five times faster rates of evolution

Sep. 12, 2013 — A new study led by Adelaide researchers has estimated, for the first time, the rates of evolution during the “Cambrian explosion” when most modern animal groups appeared between 540 and 520 million years ago.The findings, published online today in the journal Current Biology, resolve “Darwin’s dilemma”: the sudden appearance of a plethora of modern animal groups in the fossil record during the early Cambrian period.”The abrupt appearance of dozens of animal groups during this time is arguably the most important evolutionary event after the origin of life,” says lead author Associate Professor Michael Lee of the University of Adelaide’s School of Earth and Environmental Sciences and the South Australian Museum.”These seemingly impossibly fast rates of evolution implied by this Cambrian explosion have long been exploited by opponents of evolution. Darwin himself famously considered that this was at odds with the normal evolutionary processes.”However, because of the notorious imperfection of the ancient fossil record, no-one has been able to accurately measure rates of evolution during this critical interval, often called evolution’s Big Bang.”In this study we’ve estimated that rates of both morphological and genetic evolution during the Cambrian explosion were five times faster than today — quite rapid, but perfectly consistent with Darwin’s theory of evolution.”The team, including researchers from the Natural History Museum in London, quantified the anatomical and genetic differences between living animals, and established a timeframe over which those differences accumulated with the help of the fossil record and intricate mathematical models. Their modelling showed that moderately accelerated evolution was sufficient to explain the seemingly sudden appearance of many groups of advanced animals in the fossil record during the Cambrian explosion.The research focused on arthropods (insects, crustaceans, arachnids and their relatives), which are the most diverse animal group in both the Cambrian period and present day.”It was during this Cambrian period that many of the most familiar traits associated with this group of animals evolved, like a hard exoskeleton, jointed legs, and compound (multi-faceted) eyes that are shared by all arthropods. We even find the first appearance in the fossil record of the antenna that insects, millipedes and lobsters all have, and the earliest biting jaws.” says co-author Dr Greg Edgecombe of the Natural History Museum.

Read more

Water hidden in the Moon may have proto-Earth origin

Sep. 10, 2013 — Water found in ancient Moon rocks might have actually originated from the proto-Earth and even survived the Moon-forming event. Latest research into the amount of water within lunar rocks returned during the Apollo missions is being presented by Jessica Barnes at the European Planetary Science Congress in London on Monday 9th September.Share This:The Moon, including its interior, is believed to be much wetter than was envisaged during the Apollo era. The study by Barnes and colleagues at The Open University, UK, investigated the amount of water present in the mineral apatite, a calcium phosphate mineral found in samples of the ancient lunar crust.“These are some of the oldest rocks we have from the Moon and are much older than the oldest rocks found on Earth. The antiquity of these rocks make them the most appropriate samples for trying to understand the water content of the Moon soon after it formed about 4.5 billion years ago and for unravelling where in the Solar System that water came from,” Barnes explains.Barnes and her colleagues have found that the ancient lunar rocks contain appreciable amounts of water locked into the crystal structure of apatite. They also measured the hydrogen isotopic signature of the water in these lunar rocks to identify the potential source(s) for the water.“The water locked into the mineral apatite in the Moon rocks studied has an isotopic signature very similar to that of the Earth and some carbonaceous chondrite meteorites,” says Barnes. “The remarkable consistency between the hydrogen composition of lunar samples and water-reservoirs of the Earth strongly suggests that there is a common origin for water in the Earth-Moon system.”This research has been funded by the UK Science and Technologies Facilities Council (STFC).Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Europlanet Media Centre. Note: Materials may be edited for content and length. For further information, please contact the source cited above. Need to cite this story in your essay, paper, or report? …

Read more

How the brain remembers pleasure: Implications for addiction

Aug. 25, 2013 — Key details of the way nerve cells in the brain remember pleasure are revealed in a study by University of Alabama at Birmingham (UAB) researchers published today in the journal Nature Neuroscience. The molecular events that form such “reward memories” appear to differ from those created by drug addiction, despite the popular theory that addiction hijacks normal reward pathways.Brain circuits have evolved to encourage behaviors proven to help our species survive by attaching pleasure to them. Eating rich food tastes good because it delivers energy and sex is desirable because it creates offspring. The same systems also connect in our mind’s environmental cues with actual pleasures to form reward memories.This study in rats supports the idea that the mammalian brain features several memory types, each using different circuits, with memories accessed and integrated as needed. Ancient memory types include those that remind us what to fear, what to seek out (reward), how to move (motor memory) and navigate (place memory). More recent developments enable us to remember the year Columbus sailed and our wedding day.”We believe reward memory may serve as a good model for understanding the molecular mechanisms behind many types of learning and memory,” said David Sweatt, Ph.D., chair of the UAB Department of Neurobiology, director of the Evelyn F. McKnight Brain Institute at UAB and corresponding author for the study. “Our results provide a leap in the field’s understanding of reward-learning mechanisms and promise to guide future attempts to solve related problems such as addiction and criminal behavior.”The study is the first to illustrate that reward memories are created by chemical changes that influence known memory-related genes in nerve cells within a brain region called the ventral tegmental area, or VTA. Experiments that blocked those chemical changes — a mix of DNA methylation and demethylation — in the VTA prevented rats from forming new reward memories.Methylation is the attachment of a methyl group (one carbon and three hydrogens) to a DNA chain at certain spots (cytosine bases). …

Read more

Archaeologists find massive fortifications from the Iron Age in present-day Israel

Aug. 19, 2013 — Researchers from Tel Aviv University have unearthed the remains of massive ancient fortifications built around an Iron-Age Assyrian harbor in present-day Israel.At the heart of the well-preserved fortifications is a mud-brick wall up to more than 12 feet wide and 15 feet high. The wall is covered in layers of mud and sand that stretch for hundreds of feet on either side. When they were built in the eighth century B.C.E., the fortifications formed a daunting crescent-shaped defense for an inland area covering more than 17 acres.The finding comes at the end of the first excavation season at the Ashdod-Yam archaeological dig in the contemporary Israeli coastal city of Ashdod, just south of Tel Aviv. Dr. Alexander Fantalkin of TAU’s Department of Archaeology and Ancient Near Eastern Cultures is leading the project on behalf of the Sonia and Marco Nadler Institute of Archaeology.”The fortifications appear to protect an artificial harbor,” says Fantalkin. “If so, this would be a discovery of international significance, the first known harbor of this kind in our corner of the Levant.”Building up and putting downWhen the fortifications were built, the Assyrians ruled the southeastern part of the Mediterranean basin, including parts of Africa and the Middle East. Assyrian inscriptions reveal that at the end of the century, Yamani, the rebel king of Ashdod, led a rebellion against Sargon II, the king of the Assyrian Empire. The Kingdom of Judah, under King Hezekiah, rejected Yamani’s call to join the insurrection.The Assyrians responded harshly to the rebellion, eventually destroying Philistine Ashdod. As a result, power shifted to the nearby area of Ashdod-Yam, where the TAU excavations are taking place. …

Read more

Discovery of stone monument adds new chapter to ancient Maya history: New World ‘Cleopatra story’ waits 1,000 years to be retold

July 17, 2013 — Archaeologists tunneling beneath the main temple of the ancient Maya city of El Perú-Waka’ in northern Guatemala have discovered an intricately carved stone monument with hieroglyphic text detailing the exploits of a little-known sixth-century princess whose progeny prevailed in a bloody, back-and-forth struggle between two of the civilization’s most powerful royal dynasties, Guatemalan cultural officials announced July 16.”Great rulers took pleasure in describing adversity as a prelude to ultimate success,” said research director David Freidel, PhD, a professor of anthropology in Arts & Sciences at Washington University in St. Louis. “Here the Snake queen, Lady Ikoom, prevailed in the end.”Freidel, who is studying in Paris this summer, said the stone monument, known officially as El Perú Stela 44, offers a wealth of new information about a “dark period” in Maya history, including the names of two previously unknown Maya rulers and the political realities that shaped their legacies.”The narrative of Stela 44 is full of twists and turns of the kind that are usually found in time of war but rarely detected in Precolumbian archaeology,” Freidel said.”The information in the text provides a new chapter in the history of the ancient kingdom of Waka’ and its political relations with the most powerful kingdoms in the Classic period lowland Maya world.”Carved stone monuments, such as Stela 44, have been unearthed in dozens of other important Maya ruins and each has made a critical contribution to the understanding of Maya culture.Freidel says that his epigrapher, Stanley Guenter, who deciphered the text, believes that Stela 44 was originally dedicated about 1450 years ago in the calendar period ending in 564 AD by the Wak dynasty King Wa’oom Uch’ab Tzi’kin, a title that translates roughly as “He Who Stands Up the Offering of the Eagle.”After standing exposed to the elements for more than 100 years, Stela 44 was moved by order of a later king and buried as an offering inside new construction that took place at the main El Perú-Waka’ temple about 700 AD, probably as part of funeral rituals for a great queen entombed in the building at this time, the research team suggests.El Perú-Waka’ is about 40 miles west of the famous Maya site of Tikal near the San Pedro Martir River in Laguna del Tigre National Park. In the Classic period this royal city commanded major trade routes running north to south and east to west.Freidel has directed research at this site in collaboration with Guatemalan and foreign archaeologists since 2003. At present, Lic. Juan Carlos Pérez Calderon is co-director of the project and Olivia Navarro Farr, an assistant professor at the College of Wooster in Ohio, is co-principal investigator and long term supervisor of work in the temple, known as Structure M13-1. Gautemalan archaeologist Griselda Perez discovered Stela 44 in this temple.The project carries out research under the auspices of the Ministry of Culture and Sports of Guatemala and its Directorate for Cultural and Natural Patrimony, the Council for Protected Areas, and it is sponsored by the Foundation for the Cultural and Natural Patrimony (PACUNAM) and the US Department of the Interior.Early in March 2013, Pérez was excavating a short tunnel along the centerline of the stairway of the temple in order to give access to other tunnels leading to a royal tomb discovered in 2012 when her excavators encountered Stela 44.Once the texts along the side of the monument were cleared, archaeologist Francisco Castaneda took detailed photographs and sent these to Guenter for decipherment.Guenter’s glyph analysis suggests that Stela 44 was commissioned by Wak dynasty King Wa’oom Uch’ab Tzi’kin to honor his father, King Chak Took Ich’aak (Red Spark Claw), who had died in 556 AD. Stela 44’s description of this royal father-son duo marks the first time their names have been known to modern history.A new queen, Lady Ikoom, also is featured in the text and she was important to the king who recovered this worn stela and used it again.Researchers believe that Lady Ikoom was one of two Snake dynasty princesses sent into arranged marriages with the rulers of El Perú-Waka’ and another nearby Maya city as a means of cementing Snake control over this region of Northern Guatemala.Lady Ikoom was a predecessor to one of the greatest queens of Classic Maya civilization, the seventh-century Maya Holy Snake Lord known as Lady K’abel who ruled El Perú-Waka’ for more than 20 years with her husband, King K’inich Bahlam II. She was the military governor of the Wak kingdom for her family, the imperial house of the Snake King, and she carried the title “Kaloomte,” translated as “Supreme Warrior,” higher in authority than her husband, the king.Around 700 AD, Stela 44 was brought to the main city temple by command of King K’inich Bahlam II to be buried as an offering, probably as part of the funeral rituals for his wife, queen Kaloomte’ K’abel.Last year, the project discovered fragments of another stela built into the final terrace walls of the city temple, Stela 43, dedicated by this king in 702 AD. Lady Ikoom is given pride of place on the front of that monument celebrating an event in 574. …

Read more

The origin of the turtle shell: Mystery solved

July 9, 2013 — A team of researchers from Japan has finally solved the riddle of the origin of the turtle shell.By observing the development of different animal species and confirming their results with fossil analysis and genomic data, researchers from the RIKEN Center for Developmental Biology show that the shell on the turtle’s back derives only from its ancestors’ ribcage and not from a combination of internal and external bone structures as is often thought. Their study is published today in the journal Nature Communications.The skeleton of vertebrates has evolved throughout history from two different structures, called the endo- and exoskeleton. In the human skeleton, the backbone and bones of the limbs evolved from the endoskeleton, whereas most of the skull elements derive from the exoskeleton. Fish scales and the alligator’s bony skin nodules are other examples of exoskeletons.The origin of the shell on the turtle’s back, or carapace, was unclear until now because it comprises parts of obvious endoskeletal origin and others that look more like the exoskeleton of alligators and fish. The outer part of the turtle carapace was thought to have derived from exoskeletal bones, while the internal part has been shown to originate from ribs and vertebrae and to be connected to the internal skeleton of the animal. However, no direct evidence has been obtained to show that the bony structures developing outside the ribcage in turtles derived from the exoskeleton.To investigate whether the turtle carapace evolved with any contribution from its ancestors’ exoskeleton, Dr. Tatsuya Hirasawa and his team carefully observed developing embryos of Chinese soft-shell turtles, chickens and alligators.In their analysis, they compared the development of the turtle carapace, the chick’s ribs and the alligator’s bony skin nodules.The researchers found that the major part of the turtle’s carapace is made from hypertrophied ribs and vertebrae and therefore derives solely from endoskeletal tissue.This finding was confirmed by the observation of fossils of the ancient turtle Odontochelys and the ancient reptile Sinosaurosphargis, that both exhibit shells of endoskeletal origin. Odontochelys has a rigid shell instead of a flexible ribcage. And Sinosaurosphargis possesses an endoskeletal shell similar to the turtle’s under, and separate from, a layer of exoskeletal bones.Taken together these results show that the turtle carapace has evolved independently from the exoskeleton. This scenario is also consistent with the recent phylogenetic analyses based on genomic data that have placed turtles in the same group as birds, crocodiles and marine reptiles like Sinosaurophargis, contradicting recent studies based solely on fossil record.”Recently, genomic analyses had given us evidence that turtles evolved from reptiles closely related to alligators and dinosaurs, not from primitive reptiles as once thought. …

Read more

Location of upwelling in Earth’s mantle discovered to be stable

June 26, 2013 — A study published in Nature today shares the discovery that large-scale upwelling within Earth’s mantle mostly occurs in only two places: beneath Africa and the Central Pacific. More importantly, Clinton Conrad, Associate Professor of Geology at the University of Hawaii — Manoa’s School of Ocean and Earth Science and Technology (SOEST) and colleagues revealed that these upwelling locations have remained remarkably stable over geologic time, despite dramatic reconfigurations of tectonic plate motions and continental locations on the Earth’s surface. “For example,” said Conrad, “the Pangaea supercontinent formed and broke apart at the surface, but we think that the upwelling locations in the mantle have remained relatively constant despite this activity.”Conrad has studied patterns of tectonic plates throughout his career, and has long noticed that the plates were, on average, moving northward. “Knowing this,” explained Conrad, “I was curious if I could determine a single location in the Northern Hemisphere toward which all plates are converging, on average.” After locating this point in eastern Asia, Conrad then wondered if other special points on Earth could characterize plate tectonics. “With some mathematical work, I described the plate tectonic ‘quadrupole’, which defines two points of ‘net convergence’ and two points of ‘net divergence’ of tectonic plate motions.”When the researchers computed the plate tectonic quadruople locations for present-day plate motions, they found that the net divergence locations were consistent with the African and central Pacific locations where scientists think that mantle upwellings are occurring today. “This observation was interesting and important, and it made sense,” said Conrad. “Next, we applied this formula to the time history of plate motions and plotted the points — I was astonished to see that the points have not moved over geologic time!” Because plate motions are merely the surface expression of the underlying dynamics of the Earth’s mantle, Conrad and his colleagues were able to infer that upwelling flow in the mantle must also remain stable over geologic time. “It was as if I was seeing the ‘ghosts’ of ancient mantle flow patterns, recorded in the geologic record of plate motions!”Earth’s mantle dynamics govern many aspects of geologic change on the Earth’s surface. This recent discovery that mantle upwelling has remained stable and centered on two locations (beneath Africa and the Central Pacific) provides a framework for understanding how mantle dynamics can be linked to surface geology over geologic time. For example, the researchers can now estimate how individual continents have moved relative to these two upwelling locations. …

Read more

New biomolecular archaeological evidence points to the beginnings of viniculture in France

June 3, 2013 — France is renowned the world over as a leader in the crafts of viticulture and winemaking — but the beginnings of French viniculture have been largely unknown, until now.Imported ancient Etruscan amphoras and a limestone press platform, discovered at the ancient port site of Lattara in southern France, have provided the earliest known biomolecular archaeological evidence of grape wine and winemaking — and point to the beginnings of a Celtic or Gallic vinicultural industry in France circa 500-400 BCE. Details of the discovery are published as “The Beginning of Viniculture in France” in the June 3, 2013 issue of Proceedings of the National Academy of Sciences (PNAS). Dr. Patrick McGovern, Director of the Biomolecular Archaeology Laboratory at the University of Pennsylvania Museum of Archaeology and Anthropology and author of Ancient Wine: The Search for the Origins of Viniculture (Princeton University Press, 2006) is the lead author on the paper, which was researched and written in collaboration with colleagues from France and the United States.For Dr. McGovern, much of whose career has been spent examining the archaeological data, developing the chemical analyses, and following the trail of the Eurasian grapevine (Vitis vinifera) in the wild and its domestication by humans, this confirmation of the earliest evidence of viniculture in France is a key step in understanding the ongoing development of what he calls the “wine culture” of the world — one that began in the Turkey’s Taurus Mountains, the Caucasus Mountains, and/or the Zagros Mountains of Iran about 9,000 years ago.”France’s rise to world prominence in the wine culture has been well documented, especially since the 12th century, when the Cistercian monks determined by trial-and-error that Chardonnay and Pinot Noir were the best cultivars to grow in Burgundy,” Dr. McGovern noted. “What we haven’t had is clear chemical evidence, combined with botanical and archaeological data, showing how wine was introduced into France and initiated a native industry.”Now we know that the ancient Etruscans lured the Gauls into the Mediterranean wine culture by importing wine into southern France. This built up a demand that could only be met by establishing a native industry, likely done by transplanting the domesticated vine from Italy, and enlisting the requisite winemaking expertise from the Etruscans.”Combined Archaeological, Chemical, and Archaeobotanical Evidence Corroborate DiscoveryAt the site of Lattara, merchant quarters inside a walled settlement, circa 525-475 BCE, held numerous Etruscan amphoras, three of which were selected for analysis because they were whole, unwashed, found in an undisturbed, sealed context, and showed signs of residue on their interior bases where precipitates of liquids, such as wine, collect. Judging by their shape and other features, they could be assigned to a specific Etruscan amphora type, likely manufactured at the city of Cisra (modern Cerveteri) in central Italy during the same time period.After sample extraction, ancient organic compounds were identified by a combination of state-of-the-art chemical techniques, including infrared spectrometry, gas chromatography-mass spectrometry, solid phase microextraction, ultrahigh-performance liquid chromatography tandem mass spectrometry, and one of the most sensitive techniques now available, used here for the first time to analyze ancient wine and grape samples, liquid chromatography-Orbitrap mass spectrometry.All the samples were positive for tartaric acid/tartrate (the biomarker or fingerprint compound for the Eurasian grape and wine in the Middle East and Mediterranean), as well as compounds deriving from pine tree resin. Herbal additives to the wine were also identified, including rosemary, basil and/or thyme, which are native to central Italy where the wine was likely made. …

Read more

A new chapter for Chinese medicine

Oct. 5, 2012 — When comes to minor complaints, chronic conditions and even fatal illnesses, people sometimes turn to ginseng and other herbal remedies.

A team of scientists from The Hong Kong Polytechnic University (PolyU) has been working on a new approach to drug development involving chemistry, biotechnology, mathematics, computer power and 5000-year ancient practices in Chinese medicine. The groundbreaking regime for herbal study and testing called quantitative-pattern-activity-relationship (“QPAR” in short) verifies the quality and health benefits of traditional herbs. While Western pharmacology focuses on purified chemical compounds such as Vitamin C, Prof. Chau Foo Tim from the Department of Applied Biology and Chemical Technology and Dr Daniel Sze from the Department of Health Technology and Informatics studied the impact from a mix of compounds, a unique property in herbs.

“Information-rich pattern called chromatographic fingerprint were used to prove the authenticity of a medicinal plant. Our research team has further utilized the ‘big data’ three dimensional (3D) fingerprints to give a good presentation of active ingredients and bioactivities that allow scientists to excavate any healing power from a mix of compounds,” said Prof. Chau.

To further bridge the gap between Chinese and Western medicines, Prof. Chau and Dr Sze have been working on a completely new drug classification and rating standard to establish a scientific link between traditional herbs and various diseases. The new QPAR standard for the first time links medicinal properties to cells, genes and proteins that trigger or contribute to a disease. For example, the magic fungus Ganoderma (靈芝) could be investigated for its ability to improve immunity by stimulating Dendritic Cells and therefore cell-mediated immune responses in our body.

“This is an innovative framework that quantifies the effect of traditional herbs would have on human health and common diseases on a sound scientific basis. QPAR can be used to verify how well Ganoderma can boost immunity and give a rating,” said Dr Sze.

The research is still at an early stage but if successful, scientists will only have to do laboratory tests and crunch on computers to build databases, and get an accurate projection of active ingredients, efficacy and toxicity for preliminary herbal study in the future.

Another breakthrough is that QPAR uses mathematical methods to make predictions and the sophisticated algorithms tapped into 5000-year ancient system of Chinese medicine which was based on the flow and balance of positive (yang) and negative (yin) energies in the body. “We believed that blending the Chinese understanding of diseases into the western medicines would yield an approach more successful in unlocking the full potential of Chinese herbs,” Dr Sze continued.

Dr Albert B. Wong, the founding president of the Modernised Chinese Medicine Association who was also a member of Hong Kong SAR Government’s Panel on Promoting Testing and Certification Services in Chinese Medicine Trade, shared his views on this novel technique. “Health benefits of herbal remedies are widely known but not yet proven. People don’t want to waste money or gamble on unproven treatments and then miss the chance of beating the diseases. New innovations are needed to bring transparency and credibility into herbal medicine.”

Dr Wong also believed that this innovation would drive the evolution of herbal trade. “Herbs can be grown, hand-picked or collected. The quality of active ingredients and medicinal effects also varies with region, altitude, growing techniques and processing methods. QPAR provides a scientific way to quickly verify the authenticity and active ingredients by different sources, making herbal trade fairer and more transparent. Drug companies would better control the prices and quality of raw herbs and also enforce standardisation and consistence across products. From the consumers’ point of view, it is worth to spend the money on products that can give exactly what they want for their health benefits.”

Read more

The Black Sea is a goldmine of ancient genetic data

May 6, 2013 — When Woods Hole Oceanographic Institution (WHOI) marine paleoecologist Marco Coolen was mining through vast amounts of genetic data from the Black Sea sediment record, he was amazed about the variety of past plankton species that left behind their genetic makeup (i.e., the plankton paleome).

The semi-isolated Black Sea is highly sensitive to climate driven environmental changes, and the underlying sediments represent high-resolution archives of past continental climate and concurrent hydrologic changes in the basin. The brackish Black Sea is currently receiving salty Mediterranean waters via the narrow Strait of Bosphorus as well as freshwater from rivers and via precipitation.

“However, during glacial sea level lowstands, the marine connection was hindered, and the Black Sea functioned as a giant lake,” says WHOI geologist Liviu Giosan.

He added that “the dynamics of the environmental changes from the Late Glacial into the Holocene (last 10,000 years) remain a matter of debate, and information on how these changes affected the plankton ecology of the Black Sea is sparse.”

Using a combination of advanced ancient DNA techniques and tools to reconstruct the past climate, Coolen, Giosan, and their colleagues have determined how communities of plankton have responded to changes in climate and the influence of humans over the last 11,400 years. Their results will be published in the Proceedings of the National Academy of Sciences, USA (PNAS), and will be available online on May 6.

Researchers traditionally reconstruct the make up of plankton by using a microscope to count the fossil skeletons found in sediment cores. But, this method is limited because most plankton leave no fossils, so instead Coolen looked for sedimentary genomic remains of the past inhabitants of the Black Sea water column.

“DNA offers the best opportunity to learn the past ecology of the Black Sea,” says Coolen. “For example, calcareous and organic-walled dinocysts are frequently used to reconstruct past environmental conditions, but 90 percent of the dinoflagellate species do not produce such diagnostic resting stages, yet their DNA remains in the fossil record.”

However, ancient DNA signatures in marine sediments have thus far been used for targeted reconstruction of specific plankton groups and those studies were based on very small clone libraries. Instead, the researchers used a high throughput next generation DNA sequencing approach called pyrosequencing to look for the overall plankton changes in the Back Sea from the deglaciation to recent times.

In addition, the researchers reconstructed past changes in salinity and temperature as the possible causes for plankton community shifts in the Black Sea.

To reconstruct the salinity, the WHOI team analyzed sediments containing highly resistant organic compounds called alkenones, which are uniquely produced by Emiliania huxleyi — the same photosynthetic organism oceanographers study to determine past sea surface temperatures. By examining the ratio of two hydrogen isotopes in the alkenones, they were able to map the salinity trend in the Black Sea over the last 6,500 years.

“One of the isotopes, deuterium, is not very common in nature,” explains Coolen, “And it doesn’t evaporate as easily as other isotopes. Higher ratios of deuterium are indicative of higher salinity.”

The WHOI team was funded through the National Science Foundation and they collaborated with Chris Quince and his postdoc Keith Harris from the Computational Microbial Genomics Group at the University of Glasgow, and with micropaloentologist Mariana Filipova-Marinova from the Natural History Museum in Varna, Bulgaria.

Their study revealed that 150 of 2,710 identified plankton showed a statistically significantly response to four environmental stages since the deglacial. Freshwater green algae were the best indicator species for lake conditions more than 9,000 years ago although the co-presence of previously unidentified marine plankton species indicated that the Black Sea might have been influenced to some extent by the Mediterranean Sea over at least the past 9,600 years. Dinoflagellates, cercozoa, eustigmatophytes, and haptophyte algae responded most dramatically to the gradual increase in salinity after the latest marine reconnection and during the warm and moist mid-Holocene climatic optimum. Salinity increased rapidly with the onset of the dry Subboreal climate stage after ca. 5200 years ago leading to an increase in marine fungi and the first occurrence of marine copepods. A gradual succession of phytoplankton such as dinoflagellates, diatoms, and golden algae occurred during refreshening of the Black Sea with the onset of the cool and wet Subatlantic climate around 2500 years ago. The most drastic changes in plankton occurred over the last century associated with recent human disturbances in the region.

The new findings show how sensitive marine ecosystems are to climate and human impact. The high throughput sequencing of ancient DNA signatures allows us to reconstruct a large part of ancient oceanic life including organisms that are not preserved as fossils.

Coolen added that ancient plankton DNA was even preserved in the oldest analyzed Black Sea lake sediments when the entire water column was most likely well mixed and oxygenated. This means that ancient plankton DNA might be widely preserved in sediments and can likely be used to reconstruct past life in the majority of oceanic and lake environments.

Read more

Ancient Egyptians accessorized with meteorites

May 30, 2013 — Researchers at The Open University (OU) and The University of Manchester have found conclusive proof that Ancient Egyptians used meteorites to make symbolic accessories for their dead.

The evidence comes from strings of iron beads which were excavated in 1911 at the Gerzeh cemetery, a burial site approximately 70km south of Cairo. Dating from 3350 to 3600 BC, thousands of years before Egypt’s Iron Age, the bead analysed was originally assumed to be from a meteorite owing to its composition of nickel-rich iron. But this hypothesis was challenged in the 1980s when academics proposed that much of the early worldwide examples of iron use originally thought to be of meteorite-origin were actually early smelting attempts.

Subsequently, the Gerzeh bead, still the earliest discovered use of iron by the Egyptians, was loaned by The Manchester Museum to the OU and Manchester’s School of Materials for further testing. Researchers used a combination of the OU’s electron microscope and the University’s X-Ray CT scanner to demonstrate that the nickel-rich chemical composition of the bead confirms its meteorite origins.

OU Project Officer Diane Johnson, who led the study, said: “This research highlights the application of modern technology to ancient materials not only to understand meteorites better but also to help us understand what ancient cultures considered these materials to be and the importance they placed upon them.”

Meteorite iron had profound implications for the Ancient Egyptians, both in their perception of the iron in the context of its celestial origin and in early metallurgy attempts.

Dr Joyce Tyldesley is a Senior Lecturer in Egyptology at The University of Manchester and worked on the research. She said: “Today, we see iron first and foremost as a practical, rather dull metal. To the ancient Egyptians, however, it was a rare and beautiful material which, as it fell from the sky, surely had some magical/religious properties. They therefore used this remarkable metal to create small objects of beauty and religious significance which were so important to them that they chose to include them in their graves.”

Philip Withers, Professor of Materials Science at The University of Manchester, added: “Meteorites have a unique microstructural and chemical fingerprint because they cooled incredibly slowly as they travelled through space. It was really interesting to find that fingerprint turn up in Egyptian artefacts.”

The results of the study of the bead can be obtained in the paper, ‘Analysis of a Prehistoric Egyptian Iron Bead with Implications for the use and perception of meteorite iron in ancient Egypt.’ published in the Meteoritics and Planetary Science journal.

Read more

How turtles got their shells: Fossil of extinct South African reptile provides clues

May 30, 2013 — Through careful study of an ancient ancestor of modern turtles, researchers now have a clearer picture of how the turtles’ most unusual shell came to be. The findings, reported on May 30 in Current Biology, a Cell Press publication, help to fill a 30- to 55-million-year gap in the turtle fossil record through study of an extinct South African reptile known as Eunotosaurus.

“The turtle shell is a complex structure whose initial transformations started over 260 million years ago in the Permian period,” says Tyler Lyson of Yale University and the Smithsonian. “Like other complex structures, the shell evolved over millions of years and was gradually modified into its present-day shape.”

The turtle shell isn’t really just one thing — it is made up of approximately 50 bones. Turtles are the only animals that form a shell through the fusion of ribs and vertebrae. In all other animals, shells are formed from bony scales on the surface; they don’t stick their bones on the outsides of their bodies.

“The reason, I think, that more animals don’t form a shell via the broadening and eventually suturing together of the ribs is that the ribs of mammals and lizards are used to help ventilate the lungs,” Lyson says. “If you incorporate your ribs into a protective shell, then you have to find a new way to breathe!” Turtles have done just that, with the help of a muscular sling.

Until recently, the oldest known fossil turtles, dating back about 215 million years, had fully developed shells, making it hard to see the sequence of evolutionary events that produced them. That changed in 2008 with the discovery of Chinese Odontochelys semitestacea, a reptile about 220 million years old, which had a fully developed plastron — the belly side of the shell — but only a partial carapace on its back.

Eunotosaurus takes the turtle and its shell back another 40 million years or so. It had nine broadened ribs found only in turtles. And like turtles, it lacked the intercostal muscles running between its ribs. But Eunotosaurus didn’t have other features common to Odontochelys and turtles, including broad spines on their vertebrae.

Lyson says he and his colleagues now plan to investigate various other aspects of turtles’ respiratory systems, which allow them to manage with their ribs locked up into a protective outer shell. “It is clear that this novel lung ventilation mechanism evolved in tandem with the origin of the turtle shell,” he says.

Read more

Clam fossils divulge secrets of ecologic stability

May 15, 2013 — Clam fossils from the middle Devonian era — some 380 million years ago — now yield a better paleontological picture of the capacity of ecosystems to remain stable in the face of environmental change, according to research published today (May 15) in the online journal PLOS ONE.

Trained to examine species abundance — the head counts of specimens — paleontologists test the stability of Earth’s past ecosystems. The research shows that factors such as predation and organism body size from epochs-gone-by can now be considered in such detective work.

Back 380 million years ago, New York was under the Devonian sea. Today, the fossils found in the rocks of this region have become well known for documenting long-term stability in species composition — that is, the same species have been found to persist with little change over a 5 million year period. But research has found that species abundance in this ancient ecosystem went up and down, generating debate among paleontologists whether the fauna, as a whole, was also stable in terms of its ecology.

A team of Cornell, Paleontological Research Institution (PRI) — an affiliate of Cornell — and University of Cincinnati researchers revisited this debate by examining the ecological stability of the Devonian clam fauna.

“To understand how these species fared in the Devonian, you have to look at how they interacted with other species. There is more to ecology than just the abundance and distribution of species,” said Gregory Dietl, Cornell adjunct professor, earth and atmospheric sciences, and a paleontologist at PRI.

The research, “Abundance Is Not Enough: The Need for Multiple Lines of Evidence in Testing for Ecological Stability in the Fossil Record,” was written by Judith Nagel-Myers, paleontologist, PRI; John Handley, PRI; Carlton Brett, University of Cincinnati professor of geology; and Dietl.

The scientists took a new approach to testing ecological stability: In addition to counting numbers of clams, they examined repair scars on fossil clams that were left by the unsuccessful attacks from shell-crushing predators, and the body size of the clam assemblage as it yields biological information on the structure of food webs.

“Surprisingly, predation pressure and the body size structure of the clams remained stable, even as abundance varied,” said Nagel-Myers. Possible mechanisms that explain the clam assemblage’s stability are related to the dynamics of food webs — the same mechanisms operating in food webs today. In one mechanism, predators switched between feeding on different clam species as their abundance varied.

The ancient Devonian ecosystem was more complex than previously thought, as it cautions scientists against basing conclusions on a single factor. Said Dietl: “Our results thus raise serious doubt as to whether ecological stability can be tested meaningfully, solely based upon the abundance of taxa, which has been the standard metric used to test for ecological stability in paleoecology.”

Read more

Utilizzando il sito, accetti l'utilizzo dei cookie da parte nostra. maggiori informazioni

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close