Courtesy Clover_1Last Christmas, my son's girlfriend introduced me to honey-flavored yogurt, a delicious concoction of creamy sweetness. I've never been a fan of yogurt, but I immediately fell in love with this stuff, and try to keep a container of it on-hand in the fridge at all times. I can't seem to get enough of it.
One of the reasons it's so tasty is because it's made with whole milk which makes it high in fat, and therefore will make anyone who ingests it high in fat, too. Right? Maybe not.
Two new studies seem to point to just the opposite. Several middle-aged men who participated in a Swedish study and consumed high-fat dairy products, were tracked over a 12 year period and showed much less propensity of becoming obese when compared to men who followed a low or no high-fat diet in the same study. The research appeared in the journal Scandinavian Journal of Primary Health Care.
In the second study involving the meta-analysis of 16 empirical studies showed that - despite working under the hypothesis that a diet of high-fat foods leads to higher heart disease risk and contributes to obesity - no evidence supporting the claim was found. Actually, according to the study which appeared in the European Journal of Nutrition, consumption of high-fat dairy products were instead associated with a lower obesity risk.
Non-fat and low-fat yogurts still command a larger portion of the market but on the organic side of the things products with higher saturated fat content is, surprisingly, on the upswing. It's unclear why that is. A previous study involving children also showed that a low-fat diet was more likely to lead to obesity.
"There may be bio-active substances in the milk fat that may be altering our metabolism in a way that helps us utilize the fat and burn it for energy, rather than storing it in our bodies," said Greg Miller, of the National Dairy Council.
Besides the newly associated weight benefits, whole organic milk also contains higher levels of omega-3 fatty acids which help reduce the risk of cardiovascular diseases. It's also speculated that consumption of higher fat content may lead to a greater and faster feeling of being satisfied and full, and lead to a sooner cessation of the urge to eat.
For purely scientific reasons I'll be heading for the refrigerator in a moment to see if that's the case.
At the Sheffield site we encountered many different kinds of lithic material that the Oneota used at this site. As we sort through our findings there are multiple different types of lithic material that have been identified. Lithics are stone artifacts and it consists of items such as stone tools or stone flakes. There were fragments of all different colors and luster and density to them. Going through all these different kinds of tools and flakes may lead someone to think: “Where did these rocks come from?”
The most common lithic we found at Sheffield was Prairie Du Chien Chert, which makes sense because quarries can be found throughout the southeastern part of Minnesota. Another kind of lithic material we found was Tongue River Silica and this rock can be found on the western side of Minnesota. One stone that was particularly interesting to me though is Hixton Orthoquartzite since it is sparkly. We believed the lithic material made of Hixton came from quarries in west Wisconsin.
These are just three of the many lithic materials we found at Sheffield, these lithic materials are significant because of where they originate from. The Sheffield site is located along the Saint Croix River which acted as a means for transportation. Did the Oneota move from place to place and collected these rocks in their travels?
Lithics are an important part in archaeology and not just because the tools made from them look cool. The material that makes up the stone can have as much information as how the lithic material was made into a stone tool. We are not just looking at rocks, but the more we know about what types of material were being used the more we might know about the people who lived at Sheffield.
Courtesy The Science Museum of MinnesotaJoin us on December 14th, from 12-4pm, at the Science Museum of Minnesota, to talk to the KAYSC Heritage Crew and the Archaeology staff in the Archaeology Lab! Get a behind the scenes look at the artifacts from the Sheffield Site, an Oneota Site along the St Croix River! Learn about Minnesota Archaeology, and the research the Archaeology Department has been working on with the Heritage Crew! Dr Ed Fleming will be available to talk to the public about the Sheffield Site and his other projects at the Science Museum of Minnesota!
The other labs on Level 3 will be open as well! Visit the paleontology lab, ethnobotany lab, and biology labs! Visit with the other scientists who work hard to preserve the collections in the museum, and learn about their research too!
Courtesy Victor Hugo KingFifty years after the fateful day in Dallas, Texas, people are still working to find definitive answers to the details of the shooting of President John F. Kennedy.
What if the current forensic investigation techniques would have been available then? That's a question the Discovery Channel recently posed in producing the show "JFK: Inside the Target Car." Here's a quick summary of things they learned through their experiments. Click here to get more details about how this all was done.
The Dallas motorcade scene was recreated with modern-day, high tech dummies situated in a car. The dummies were made of materials that have similar properties to human flesh, bone and blood. Sharpshooters then shot the surrogates from the model depository, the grassy knoll, and four other plausible locations that are part of assassination theories.
Two forensic experts, who had no knowledge that the situation was set up to recreate the shooting in Dallas, examined the evidence. Their finding was that shots came from above and behind the pathway of the car, a finding consistent with the location of the Texas Textbook Depository.
Up-to-date science was also applied in making a 3-D animated simulation of the assassination scene based on angles of possible bullet paths, information from the Zapruder home movie of the motorcade, and also wind speeds and directions. Based on blood spatters created through those simulations, the origin of the fatal shots had to be from the textbook depository.
Experts add that while modern science more accurately determine where the shots were fired from, they still cannot determine without doubt if Lee Harvey Oswald was the shooter.
How do you feel about this new application of science to this dark moment of American history? Does it answer your questions on the assassination? Share your thoughts with other Science Buzz readers.
Here's a link to the Discovery Channel's website for the show.
When someone tells you about your nice features you should tell them how fun it is to excavate. I am talking about features in archaeology, of course. A feature is information that contains a cultural importance and cannot be taken to the lab the way it was found.
Examples features are hearths and post-molds. These features are located when the soils have certain qualities in them. Since archaeologists must keep digging to learn more from their block, the feature is destroyed as you dig the feature out. Another example is when artifacts are found together or next to other features. You can see this when artifacts are given context to where they are found. A group of shells found together has more cultural value than individual artifacts by themselves in an excavation unit. Just as how a piece of bone have more meaning when it is found in a fire hearth. As I have said before, the further we excavate down into our blocks we destroy the features, so in order for features to be represented, archaeologists record the features they find as they excavate.
To record features that are a part of the soil, archaeologists draw and map out the block that they dig with each layer that they dig out. In doing so they will have somewhat of a 3-D map of where the feature was in their block. At the Sheffield site we normally dig ten centimeters per layer and record what we find on the surface. When we find a feature we start digging in five centimeters layers. We dig in smaller layers so that we can record the shape of the feature more accurately. The behavior of how we dig also changes. Sometimes we dig out certain sections of the feature in order to record how the feature looks from the side.
Archeology is ultimately a destructive science and keeping a good record is key for a good analysis. The features we see as we dig will not physically be there when we go analyze our data in the lab. The more data we record from our features the more chances we have of making a cultural connection with our findings. Features are one of the most important parts of archeology because it gives the artifacts and other data more meaning to why they might be there. Without features archeology would just end up as a display of objects without any cultural significance.
Courtesy Mark RyanOver the past couple years, Science Buzz has posted several stories (here and here) about the humongous patches of garbage and plastic debris found floating in the world's oceans. It's a serious problem and one that should raise red flags for anyone concerned with the Earth's environment. But even more troubling is the recent news that plastic particles have now been found in all five of the Great Lakes lining the border of the USA and Canada. Unlike the large globs of plastic clogging areas of the ocean, the plastics polluting the Great Lakes are microscopic particles detectable only in a microscope. But they're no less disturbing.
A team of researchers led by Dr. Sherri “Sam” Mason, professor of chemistry at SUNY-Fredonia has been gathering water samples and reported finding high concentrations of plastic particles in the chain of freshwater lakes. One of the researchers involved is environmental chemist Lorena Rios-Mendoza from University of Wisconsin-Superior. Both she and Mason have studied the Great Trash Island (aka Trashlantis) in the Pacific Ocean but has now turned their attention to the Great Lakes.
Most of the plastic found in the water is visible only under a microscope, but has been found in all five of the Great Lakes, both in the water column, and in lake sediment. The amount of micro-plastic varies between lakes with Lake Erie - the shallowest and smallest by water volume - containing the largest ratio and Lake Superior - the largest and most voluminous - a much smaller ratio. But it doesn't matter; the point is that we're polluting some of our important sources of fresh water with plastic.
It's thought that cosmetics with could one of the sources, since the industry relies heavily on using micro-beads in its products. These tiny plastic particles used on our faces, skin, and teeth, eventually get washed off into the water supply where they're too small to get filtered out. But cosmetics certainly aren't the only source.
Courtesy tedxgp2Think of the ungodly amount of plastic material we use and discard every year. Surprisingly, only about five percent of the bags, bottles, cups, electronics, etc. get recycled; most plastic trash ends up in landfills where it slowly degrades and eventually finds its way into the world's favorite garbage dump: the oceans.
“We have no idea how long some of these plastics stay in the ocean, could be more than 40 years,” Rios-Mendoza said. She also worries if organic toxins in the water can attach themselves to the tiny plastic particles, and end up in the food chain. In this regard, Rios-Mendoza has been sampling Great Lake fish to see if such toxic particles are present in their guts.
It's important to remember that only 3 percent of the world's water is freshwater and the five Great Lakes - Superior, Huron, Michigan, Ontario, and Erie - together contain 20 percent of that freshwater. That's a large portion of a relatively scarce and essential life ingredient. Last fall, I posted an interesting graphic that illustrates nicely Earth's total water supply versus fresh water and puts things in perspective.
Courtesy Mark RyanRios-Mendoza and Mason have been collaborating with a research and education group called 5Gyres Institute that monitors and studies garbage patches found in five subtropical gyres in the world's oceans. Rio-Mendoza presented a preliminary study of their work on the Great Lakes at a recent meeting of the American Chemical Society. The team's future studies involve pinpointing the sources of plastic pollution and acquiring a better understanding of how plastics degrade in the environment.
"We all need to become aware of how much plastic we use in our lives and avoid using single-use products. Don’t buy water in plastic bottles or cosmetic products with micro beads. Bring re-usable bags to the store with you. Simple things like this make a big difference, but it’s also important to keep talking about this issue and raising awareness about how it affects the Great Lakes and the world’s oceans.” --- Dr. Sherri Mason“
By the way, here in Minnesota, and situated at the western tip of Lake Superior, the city of Duluth was recently proclaimed to have the best tasting drinking water in the state. By best-tasting, I'm assuming they mean it has no taste whatsoever since water is described as a colorless, tasteless liquid. Whatever the case, I always thought Duluth's drinking water was the best while growing up there (my grandparents lived in a Twin Cities' suburb and I never liked the taste of their softener-treated water).
In another water-related story, it's estimated that life on Earth can survive for at least another 1.75 billion years until we move out of the habitable zone and our oceans (and other water sources) will evaporate in the increased heat. So it's probably best that we take care of what water we have - it needs to sustain us for a long time.
Heritage went to the Sheffield on August 20th and the 21st to help out with the excavation. We learned how to screen for artifacts, measure the depth of our unit using datum points, and we learned how people use the data from geophysics to select where we should dig.
Courtesy Science Museum of MN
Screening for artifacts is when we sift through the dirt we dug from our unit. We use a tool called a screener that lets the loose dirt through so we can see the artifacts better. To get rid of the clumpy dirt we pushed it through the screen with our hands. The first unit we were at was called Block Two and we found a lot of artifacts in that unit. We learned how to recognize what was an artifact and what was not. Lithics, or stone that have been worked, have a sharper edge and a distinct pattern when it is shaped. Bone fragments are usually lighter in color than most of the items on the screener and you can see holes that are porous spots in them that make bones lighter in weight. To identify pottery they have a certain color on one side and a different one on the other side. When you look at pottery fragments from the side it looks like it has layers and the outer and inner faces of the pottery are flat. Sometimes you see small indents in the pottery meaning that it was tempered but the temper decayed away.
Courtesy Science Museum of MN
When we are digging in a unit we have to dig across and go down layer by layer. To make sure we stay level as we dug we use a datum point. A datum point is a point we designate to measure from. We tie a string to the datum point and to make sure it’s always level to the datum point there is a line level attached to it. To measure the depth of our unit we made sure the string is taut and nothing is obstructing its path, then we take a tape measure and put it perpendicular to the string and then take the measurement in centimeters. We record the unit every time we dig down ten centimeters by taking pictures and drawing sketches of the unit.
Courtesy Science Museum of MN
Geophysics is where we collect data from the ground to choose where a likely spot to dig would be. One of the machines used to determine the locations of the Sheffield units looks at the electrical resistance in the ground. Less resistance usually indicated that the ground was dug up and refilled. Resistance low areas might have been a fire pit or other settlement features thus making it a good site to look for artifacts. Another machine can spot magnetic differences in the ground. Dirt has different magnetic outputs from rocks and artifacts. One area of the site has a very different magnetic output so the team decided to put block three in that area to dig there. The last method we used to determine the location of our units was using lidar technology. Lidar is where you use shine light on an area and study how the surface reflects to map out the surface of the area.
Courtesy Science Museum of MN
Overall, I had a lot of fun at the site especially when I found pottery. I find pottery more interesting than lithics or bone for reasons I do not know why. It was really hot and humid but no one passed out so it was fine. Before we started digging we helped sift through the dirt in block two and we found a lot of pottery and debitage, or flakes, from stone tools. We even found an intact arrow point. We were assigned to dig in Block 3 where the magnetic anomaly was, but we only found one fragment of pottery and the rest were roots and rocks so digging there wasn’t so exciting. Learning from Ed, Jasmine, Mary, and Anne on the field has been very fun. I can understand why they like doing this for a living.
On Wednesday July 30th The Heritage crew took a small lesson on flint knapping with Rod Johnson. Rod has been flint knapping for about 30 years and he pursued this skill because it related to his work with archeology.
After a small power point about the history and different styles of flint knapping we were given some hands on experience on how you flint knapp.
Rod also showed us the marks that are present in flint knapping that differs from regular rocks. Being able to distinguish these marks is a good skill to have when figuring out if an item is a worked artifact or just a random rock. One of the marks is called the bulb of percussion. The bulb of percussion is the part of the rock that swells into a bulb after you hit it. Following the bulb of percussion are ripples in the rock. It looks like you dropped something into a river and seeing its ripples but instead of dropping you strike the platform and instead of river it’s a rock and instead of the ripples fading it stays frozen into the rock.
Courtesy SMMIn an area called Kasota, a kid found a mysterious mandible in the riverbed. A mandible if you don't know is the lower jawbone of an animal. My friends and I all believed it to be a cow, elk, or a moose skull. After researching and comparing it to other skulls we found out that it was indeed a cow skull.
We went to the Science House in the Science Museum of Minnesota to compare our mandibles to the ones in their collection. When we compared it to the elk mandible, our mandible was the same length but it was obvious that bone between the teeth and the bottom of the mandible was narrower on the elk mandible. Our mandible was too big to be any deer mandible so we were certain it was not a deer mandible. When we were comparing it to the moose our mandible seemed a little too small to be a moose mandible. When we compared it to the cow mandible it was almost a perfect match. So we concluded that it was the mandible of a cow.
Courtesy Mark RyanI've had the great fortune of being able to volunteer in the paleontology lab at the Science Museum of Minnesota. I'm in my fourth month there and it's been a real blast. My first project was preparing (cleaning) the skull of a small oreodont collected from the White River Formation in Wyoming. This is the same formation exposed in the fossil-rich South Dakota Badlands. By cleaning, I mean removing all the rock (matrix) in which the skull is encased. I've also helped patch up the casts of a couple of lambeosaurus skulls, and spent a few days puzzling over a crocodile skull reduced to about 1000 pieces.
Courtesy Mark RyanAt the moment, preparators been working on the remains of a 52 million year-old gar collected from the Green River Formation in southwestern Wyoming. Most of the work is being done by the more experienced volunteers in the lab but I've been able to help a little, taking my turn with the air scribe to reveal some caudal scales in their rocky grave. This particular specimen, an ancient member of Lepisosteus, was collected in Lincoln County, Wyoming. It's fascinating work uncovering something that last saw sunlight more than 50 million years ago. Now, at least, its remains can bask in the glare of the paleo lab's artificial lights.
Courtesy Mark RyanFifty some million years ago, the gar lived in a large body of water known as Fossil Lake, one of three intermountain lakes that existed at different times in a sub-tropical environment in that part of Wyoming. The intermountain basin in and around the lake teemed with both floral and faunal life that over about 4000 years lived and died and were fossilized forming one of the great Lagerstätten in the world. The surrounding mountains were composed mainly of limestone, and the rivers and streams eroding those mountains carried high levels of calcite (CaC3) into the lake, resulting in a high sedimentation rate that added to the ideal fossilization environment.
Most of the fossils coming out of the Fossil Lake strata have been fossilized by a process called permineralization, where mineral-rich water permeates all the spaces and pores in the skeleton and the minerals (in this case calcite) crystallize out of the water replacing bone material down to the cellular level. Some carbonization is also involved. This process depletes the remains of volatiles and is caused by the heat and pressure of sediment compression, which also crushes and flattens the fossils, and tends to color them either brown or black.
Courtesy Mark RyanThat's very apparent with our gar. Although only portions of the fish's remains have been exhumed (its head and tail) the fossil is already providing some information about what followed the gar's death (taphonomy). Lepisosteus favored the shallow, swampy edges of Fossil Lake and when it died it probably floated on the surface for a while giving bacteria time to enter its mouth and gills and begin their decomposition work before the corpse was buried beneath sediments.
We can deduce this scenario by the manner the remains are preserved. The bones of the gar's skull and jaws are scattered and jumbled in a mish-mash of bones and scales. The head appears to have been blown apart, and that's probably what happened. As the microbes feasted on the fish's head, they released gases inside the corpse which built up, and bloated the gar to a point where it burst from the internal pressure. The mandibles, the cranium, and other bones broke apart before settling to the bottom and are disarticulated. The very end of the tail, however, shows no such disruption. The rays of the caudal fins looking almost as fresh as they did when the gar died half a million centuries ago.
Courtesy Mark RyanThe scales of its mid-section are beginning to come to light. These diamond-shaped structures were covered with ganoin, an enamel-like tissue containing less than five percent organic material. The mineralized tissue gave Lepisosteus a very tough, predator-resistant exterior when it was alive but not so resistant to the bacteria that attacked the gar from the inside after it died. Preliminary work of the mid-section is showing signs of decomposition there but further work required.
One of the major experts on the fossils found in the Green River Formation is Lance Grande, a graduate of the University of Minnesota (and elsewhere) who has been working at Chicago's Field Museum for the past few decades. In the early '80s, Dr. Grande wrote a hefty bulletin titled Paleontology of the Green River Formation for the Wyoming Geological Survey, and has now come out with a new book titled The Lost World of Fossil Lake: Snapshots from Deep Time. In a recent television interview, Dr. Grande talked about his book and about the fossils found in the Green River Formation.
Hundreds of thousands of finely preserved fossils from Fossil Lake deposits can be found in museum displays and on rock shop shelves world-wide. The best fossils were buried quickly and preserved in near pristine condition. Many of these come from what used to be the deep center of the lake where conditions were probably anoxic and burial fairly swift. At times during Fossil Lake's history events like seasonal algal blooms or rapid turnovers of the water column occurred and caused massive die-offs of fishes. Other fish, like our gar, probably just died a regular death.
Courtesy Mark RyanEvery fossil tells a story, and our gar is no exception. Back in the Eocene epoch it lived for a short time in the then subtropic environment of southwest Wyoming, doing what gars do before it finally died along the shores of Fossil Lake. After it was buried, it was fossilized, dug up, and transferred to the collections vault of the Science Museum of Minnesota. A few months ago, it was retrieved from the vault and brought into the paleo lab where it's been worked on each week by several people. Whatever the gar was thinking when it was alive back in the late Eocene, you can be sure it was unaware that its post-mortem life would provide hours of detailed work, study and fascination for another curious life-form 52 million years later.
SOURCES AND LINKS