(Credit: Image courtesy of Southern Methodist University)

Certain isotopic measurements carried out on fossil land snail shells, have yielded oxygen isotope ratios indicating that the relative humidity on the islands was at a higher level 50,000 years ago, before undergoing a long-term decrease to the time of maximum global cooling and glaciations, some fifteen thousand to twenty thousand years ago. Such research was headed by Yurena Yates, a post-doctoral researcher, and geochemistry professor Crayton J. Yapp; based at the Roy M. Huffington Department of Earth Sciences of Southern Methodist University in Dallas, Texas.

The finding suggests that, relative humidity has truly oscillated somewhat in the midst of subsequent post-glacial climactic fluctuations; but it would end up decreasing even further to modern values. This is what has caused an overall dryness in the eastern Canary Islands over the last 50,000 years – according to Yanes. The low-altitude areas are marked by low annual rainfall rates and a landscape consisting of short grasses and shrubs. The research itself is an advancement of the understanding of the worldwide paleoclimate, at an important time in the history of human evolution: when hunting and gathering shifted to agriculture (originally in the Middle East, before spreading elsewhere).

This isotopic evidence is indicative of changing atmospheric and oceanic circulation in connection with the waxing, waning and disappearance of vast ice sheets during the last 50,000 year period, at mid-to-high latitudes along the continents of the Northern hemisphere. Furthermore, this research shows consistency with the observed decline in diversity of the very moisture-sensitive land snails.

About the land snail shells: they are abundant and sensitive to changes in the environment; and they are well-preserved as fossils. It is a fact that measuring the variations in fossil shells’ oxygen isotope ratios is capable of yielding information to do with changes in ancient-time climactic conditions. The shells are composed of calcium, oxygen and carbon, which together form the mineral aragonite.

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Nanotechnology, or more affectionately nicknamed as nanotech, is a field of research that deals with controlling matter on an atomic or molecular level. This has multiple applications that range anywhere from electronics, to energy production, to engineering, to physics, and even to medicine. In the field of medicine alone, nanotech is giving rise to tools and possible applications that are now being streamlined to focus on finding and eradicating cancer cells. This is a particularly timely issue because cancer is now the foremost killing disease of the modern times. As humankind evolves into the new millennia, it seems that cancer cells are evolving as well. As such, there are still no known medicines or medical procedures that can prevent or cure the occurrence of any type of cancer.

The Role Of Nanotechnology In Medicine

Cancer, or any disease for that matter, begins and ends with the tiniest life force within the human body. These are the living cells that carry out the multiple complex functions necessary for life. Unfortunately, with today’s tools for diagnosis and surgical procedures, there is always the possibility that: damaged, infected and disease-carrying cells are overlooked (and thereby not eradicated by the treatment); and that the surgical procedure might actually do more damage as opposed to letting the disease run its course. It is not uncommon for cancer cells to metastasize to other organs in the body after removing the cancer afflicted part – even with aggressive chemotherapy. It is also not uncommon to hear patients dying from the surgical procedures or surgery patients suffering from the complications of the post operative treatments.

With nanotech, medicine has a fighting chance against cancer cells by producing diagnostic tools that can pinpoint the occurrence of cancerous growths as they happen; and by removing these in the cellular level that the afflicted body does not even have to be surgically opened. Nanotech has paved the way for various possibilities in diagnosis, cure and prevention of all possible diseases. Most of these are still a few technology tweaks along the way. However, the point is: the potential is now here and what may have been sheer impossibilities a good 50 years back are now becoming real by the minute. Right now, all eyes are focused on cancer research.

Cancer research with nanotech is particularly useful when it comes to the development and construction of smaller but more efficient cancer detection gadgets that can be easily replicated with the right technology. This means that formerly expensive diagnostic tools for cancer detection can now be made at more economical rates. Complex molecular machines can also be started on and developed further to help with correct and early disease diagnosis. One possibility that a lot of nanotech researchers are trying to develop are the molecular computers that not only works as a diagnostic tool but can be used as a search-and-destroy “operative” that can eradicate cancer cells on a cellular level. This is a proposed alternative to the various cocktails of medications and the series of medical procedures that one cancer patient has to endure just to slow down the process of cancer growth.

“This is the barbecue pit,” says Blackhorse, pointing to the foot of a well-preserved, two-story building that archaeologists have interpreted as a rare, above-ground religious chamber known as a tower kiva. Unlike most Navajo who have strong taboos against dealing with the deceased, Blackhorse is not afraid of burials or places associated with the dead, such as ancient sites like Kin Klizhin.

“Yep,” agrees Stein. “They be cooking up some stuff here.” He walks carefully around the tower kiva’s perimeter as if he were examining it for the first time. A beanpole with a droopy mustache, Stein is an Anglo who has spent the better part of his life safeguarding archaeological sites for the Navajo Nation. He has put in 40 years studying Chaco alone and is the supervisory archaeologist for the Chaco Sites Protection Program, which represents Navajo interests in the management of sites associated with the canyon.

Both are well regarded in Southwestern archaeological circles, but I’m confused by their talk of cookouts. The National Park Service (NPS) signpost at the path’s entrance vaguely describes Kin Klizhin as a place of “ceremonial function.” But Blackhorse explains that the kiva served as a human sacrificial altar and a center for ritual cannibalism. His story, like everything else about Chaco according to Navajo belief, is about the Gambler, an evil magician with a hooked, crooked nose who enslaved the ancient Navajo and forced them to build the great houses of Chaco.

According to Blackhorse, the Gambler rode out to Kin Klizhin on a large reptile that was his guardian. His priests sacrificed humans at the site, and the Gambler, says Blackhorse, came here “to swallow their souls.” This is not the tale the NPS tells visitors to Chaco.

Much of Chaco’s history remains shrouded in mystery, but the orthodox interpretation is that by 1050, it had become a ceremonial, administrative, and economic center. The massive great houses, the largest of which stood more than three stories tall, were connected by roads linking 150 of them in the Four Corners region.

Most scholars agree Chaco served as a special gathering place, where many Pueblo peoples and clans converged to share their ceremonies and traditions. But Blackhorse and Stein disagree with this benign view of Chaco. They also don’t think that the modern Hopi of Arizona and the Rio Grande Pueblo groups of New Mexico are the sole heirs to Chaco’s cultural heritage. Instead, the two contend that Chaco was a melting pot of various Native American groups, and argue that Navajo cosmology, oral tradition, and Chaco’s building design all point to a strong link between the Navajo and the Anasazi. Blackhorse’s master narrative is straight out of Navajo oral history: Chaco was designed and built by the Navajo at the behest of the Gambler, a Lex Luthor-type villain who came from the south and enslaved the Navajo after beating them at games. He then used Chaco’s dark energy to gain control over nature and build a sprawling empire in the Four Corners. According to the Navajo legend, the Gambler also enslaved the Pueblo people.

But the evidence for this story in the archaeological record is slight. When I ask NPS archaeologist Roger Moore if he knows anything about Kin Klizhin being used for human sacrifice and cannibalism, he tells me the site hasn’t been officially excavated. “There’s no way of knowing,” he says. “From an archaeological standpoint, we can’t substantiate it and we can’t deny it.” Stein concedes the theory that the Navajo descend from the Anasazi is “incredibly unpopular” among Southwestern archaeologists. (The very word Anasazi, a Navajo noun Blackhorse translates as “ancient ones,” is controversial.) The NPS, despite its Pueblo-centric narrative, is more receptive. Prompted by the 1990 Native American Graves Protection and Repatriation Act (NAGPRA), the NPS ruled in 1999 that the Navajo–along with 18 modern-day Pueblo tribes–had ancestral affiliation to Chaco Canyon, which borders the Navajo reservation. The decision came after federal researchers completed an exhaustive inventory of Chaco’s collection of human remains and ceremonial objects.

First built around 1700, Three Corn Ruin is one of many pueblitos, or small masonry dwellings, that the Navajo constructed on mesas and other defensible locations in the Four Corners area. (Courtesy National Park Service)

But no archaeological evidence for the Navajo’s prehistoric ties to Chaco was cited in the decision. Rather, the NPS relied largely on Navajo oral history. The story of the Gambler, and its significance in Navajo culture, was cited specifically.

The decision stunned the archaeological world. The scientific consensus is that the Navajo belong to the Athabascan language group, whose members are found mainly in Alaska and Canada (the Apache are also Athabascan). It’s thought that the ancestors of the modern Navajo didn’t even enter the Four Corners until about the 1500s, almost 300 years after Chaco was abandoned. Archaeologists believe the Navajo adopted some Pueblo traits after their arrival in the Southwest. Following the Pueblo Revolt against the Spaniards in 1680, some Pueblo groups sought refuge with the Navajo. The two groups intermarried and their cultures became entwined to a certain extent. “The Navajo weren’t Navajo until they started integrating Pueblo traits,” contends Michael Yeatts, an archaeologist with the Hopi tribe. As an example, he points to the Navajo Yeibechi healing ceremony, which he says resembles certain Hopi rituals.

There are other intriguing cultural similarities between the Navajo and Pueblo tribes. The Acoma, a Pueblo tribe in New Mexico, have a similar Gambler story that explains the ruins of Chaco, but omits the Navajo. Additionally, numerous mythological characters, including the Hero Twins, also found in Mesoamerican lore, figure prominently in both Navajo and Pueblo origin stories.

Unsurprisingly, the Navajo chafe at the notion that they co-opted Pueblo history as their own. “We have always been here,” says Blackhorse, referring to the Four Corners area.Read more here .

An examination of a fungus that is found in the ancient dung and preserved in lake sediments has helped build a picture of what happened to the beasts.The study sheds light on the ecological consequences of the extinction and the role that humans may have played in it.Researchers describe this development in the journal Science.

The study was led by Jacquelyn Gill from the University of Wisconsin, Madison, in the US.

She and her colleagues studied the Sporormiella fungal spores contained in the sediment deep within the bed of Appleman Lake in Indiana.

Many very large mammals including mammoths, mastodons and ground sloths inhabited forests in this area of North America about 20,000 years ago.

Sporormiella produces spores in the dung of large herbivores. These are then preserved in the layers of mud and can provide an index of the number of these great animals, or megafauna, that roamed the environment at a particular time.

“Sediment cores are much like ice cores, except with lake mud,” explained Ms Gill. “The spores [and other materials] settle out into the lake mud and get buried over time.”

She and her team simply counted the pollen, charcoal and Sporormiella in these layers of mud, tracking the timescale of ancient environmental changes.

Their results showed a slow decline in megafauna that began about 15,000 years ago and appeared to last for about 1,000 years.

This discovery rules out one idea that the extinction might have been caused by an extraterrestrial object striking Earth 13,000 years ago.

The scientists also spotted signals of major environmental changes around the time of the extinction.

“This study is exciting because we’re getting some solid data about the ecological consequences of the removal of these animals,” said Ms Gill.

“After their decline we see an increase in the more warm-adapted deciduous trees, and an increase in charcoal [which means there was] an increase in the number of forest fires.

“So we can see that the forest is reassembling following the extinction.”

Human or environmen

The study also shows that the decline began about 1,000 years before the Clovis period – when the archaeological record shows that humans were making stone tools designed specifically to hunt large animals.

Prior to this discovery, some scientists believed that Clovis people hunted the animals to extinction.

But Professor Christopher Johnson from James Cook University in Queensland, Australia, said the study still supports the hypothesis that humans were primarily responsible for the mammals’ decline.

Professor Johnson was not involved in the study but wrote an accompanying article in the same issue of Science, outlining its significance.

He wrote: “If people were responsible… they must have been pre-Clovis settlers.

“The existence of such people has been controversial, but archaeological evidence is slowly coming to light.”

Ms Gill commented: “We can’t resolve the climate versus humans debate but we have eliminated one of the main hypotheses for each camp.”

She added that there were “modern conservation implications” to the study.

“We know the large herbivores on the landscape today are some of the most threatened,” she said.

“And we’re starting to learn that they’re ecological keystones. They’re not just charismatic, they might also be ecologically significant.”

Professor Johnson told BBC News: “If we want to understand the history of ecosystems across the planet we really need to understand the effects of megafaunal extinction.” Source:  BBC

After years of study, the researchers have begun to piece together the bizarre story of the boneworms, all of which are in the genus Osedax. The worms start out as microscopic larvae, drifting through the darkness of the deep sea. At some point they encounter a large dead animal on the seafloor. It may be a whale, an elephant seal, or even the carcass of a cow that washed out to sea during a storm. Following chemical cues, the tiny larvae settle down onto the bones of the dead animal.

Once settled, the boneworms grow quickly, like weeds after a rain. One end of each worm develops feathery palps, which extract oxygen from seawater. The other end of the worm develops root-like appendages that grow down into the bone. Bacteria within these roots are believed to digest proteins and perhaps lipids within the bones, providing nutrition for the worms.

Soon the worms become sexually mature. Strangely enough, they all become females. Additional microscopic larvae continue to settle in the area. Some of these larvae land on the palps of the female worms. These develop into male worms. But they never grow large enough to be seen by the naked eye. Somehow these microscopic male worms find their way into the tube that surrounds the female’s body. Dozens of them share this space, not eating at all, but releasing sperm that fertilize the female’s eggs. Eventually the female worm sends thousands of fertilized eggs out into the surrounding water, and the cycle begins again.

Dr. Robert Vrijenhoek, an evolutionary biologist at MBARI, has been fascinated with these worms ever since he and his colleagues first discovered their unusual lifestyles and bizarre reproductive habits. Vrijenhoek has been trying to find out how widespread and genetically diverse these worms are. He would also like to know how they manage to find and colonize the bones of dead whales in the vast, pitch-black expanse of the deep seafloor.

Between 2004 and 2008, Vrijenhoek’s research team towed five dead whales off of Monterey Bay beaches and sank them at different depths within Monterey Canyon. Every few months, coauthor Shannon Johnson and others on the team would send one of MBARI’s remotely operated vehicles (ROVs) down to study the worms and other animals that had colonized the whale carcasses.

To their surprise, the different whale carcasses yielded different types of boneworms. One whale carcass hosted three or four different types of worms. After examining all of the worms, coauthor Greg Rouse concluded that most of them were entirely new to science. The researchers also discovered that the worms would colonize cow-bones placed on the seafloor, which showed that the worms were not limited to feeding on dead whales.

In their recent paper in the journal BMC Biology, Vrijenhoek and his coauthors describe the results of extensive DNA analyses on all the different types of Osedax worms that have been discovered so far (including two species found off Sweden and Japan). This work suggests that these worms could belong to as many as 17 different species, most of which have yet to be named. None of the worms appear to interbreed, despite the fact that some of them grow side by side.

Based on their appearance and similarities in their DNA, the researchers divided the boneworms into several groups. Some of the worms have feathery palps, which may be red, pink, striped, or even greenish in color. Others have bare palps. One type of boneworm has no palps at all. Its body forms a single, long, tapering tube, which curls at the end like a pig’s tail. This worm has evolved to live in the seafloor sediment near a dead whale. It sends long, fibrous “roots” into the mud, presumably in search of fragments of bone on which to feed.

Knowing how fast the DNA of these worms changes (mutates) over time, the researchers can calculate how long it has been since worms in the genus Osedax first evolved as a distinct group. Using one possible estimate of mutation rates, the researchers hypothesized that this group could have evolved about 45 million years ago — about the time the first large open-ocean whales show up in the fossil record. Alternatively, the worms may have evolved more slowly, which would suggest that the genus is much older, and first evolved about 130 million years ago. If this second estimate is correct, the worms could have feasted on the bones of immense sea-going reptiles during the age of the dinosaurs.

Eventually the researchers will give all these new worms their own species names. First, however, they must collect enough samples of each possible species for additional laboratory analysis and distribution to type-specimen collections. Like a classic horror story, the macabre saga of the boneworms will continue to thrill marine biologists for years to come.

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Adapted from materials provided by Monterey Bay Aquarium Research Institute via sciencedaily

The scientist while studying the effect of magnetism tells how human lungs are badly affected with particles emitted by the vehicles. As a result of the exposure the lungs are badly affected and the diseases like asthma and other respiratory troubles. It is revealed from a study that leaves of the trees that stand by the highways are more magnetic than that of the leaves of the forests. The cause is rather simple. The trees in the forest are not exposed to such a tremendous amount of pollution that the trees in the cities naturally are. As a result the quantity of pollution always varies.

To gauge the quantity of pollution it needs many air-quality monitoring stations. Hence it is very hard to locate the percentage of pollution in the air. There is no effective study of pollution emitted from the running vehicles. But if the magnetized systems come in the fore front the places with high density of pollution can easily be pinpointed. Thereafter it may help the planners of the city to design the networks for healthier transportation.

If the leaves are collected the picture comes to the limelight how badly affected the areas surrounding the highways really are. The scientists at ease come to the conclusion that the effect of polluted fume has a bad effect on the nature too. They no longer need to collect the samples from the trees to examine the quantity of carbon dioxide. The magnetized leaves would bring before them the needed data. Then it would be of great help to the scientists to assay the quantity of polluted particles emitted by vehicles. Even the kids, if they are trained, can be able to measure the level of pollution without using any equipment. The magnetized leaves would be enough.

It is noted by a group of researchers that human life as well as the aquatic life is really at stake at this present moment. According to the researchers the creatures living at the close proximity of water such as the crabs and other insects that have to depend on river water are dreadfully endangered. They are carrying on research how badly the aquatic life is affected as a result of rampant use of insecticides in the fields.

The researchers of Helmholtz Centre for Environmental Research have invented a necessary tool that can provide enough data regarding the danger of the organisms and the harmful effect of insecticides on water sources. The researchers are on the way to collect data from different corners of the globe and carry on thorough study to gauge how fatal the effect on insecticides on the organisms is. Thus it also comes to the purview of the researchers where the water is absolutely polluted, where the level is a bit lower. Following this method researchers from France, Germany and Finland have been able to collect the regional data to evaluate the extent of pollution.

According o the researchers if the calculation method is followed suitable steps can be adopted to curb the pollution of the rivers from the grasp of pesticides. According to a scientist from the calculation method it can be known where water is yet to be polluted and how the pure water is trying to compensate the infected water of the rivers. If this effort is successful the avenue of conservation method can be widened. Giving stress on the particular tool the scientist referred that if conservation is successful the complex chemical tests that need much fund can be avoided.