Author Archives: Greg

The largest pterosaurs have not been grounded yet

In one post (New evidence on the size of pterosaurs) we explored the study by Henderson (2010) in which he modeled pterosaur body forms to generate estimates of body mass. He modeled different areas of the body separately, applying various densities to the different body sections to calculate his masses. His results suggested that the largest pterosaurs like Pteranodon (wing span of 17.5 feet) and Anhanguera (wingspan 13.5 feet) weighed about as much as the heaviest flying birds (41 and 14 pounds respectively). He reasoned that birds represent a reasonable analogy for flying limits in vertebrates, so this range of masses could represent the upper limit of being able to have powered flight in vertebrates.

His results for the giant pterosaur Quetzalcoatlus were astonishing. His calculations suggest that this animal weighed in at 1200 pounds, with a wingspan of almost 37 feet. After discussing various ways to interpret this result, Henderson suggested that maybe these truly giant animals did not fly at all, but were secondarily terrestrial. This evolutionary track can be found among the birds with giants like ostriches and emus growing large and losing the ability to fly.

The giant pterosaur Quetzalcoatlus northropi compared to a modern giraffe. Illustration by Mark Witton.

The giant pterosaur Quetzalcoatlus northropi compared to a modern giraffe. Illustration by Mark Witton.

Henderson’s work and conclusions was challenged by Witton and Habib (2010). Their criticisms involve several arguments. First, they suggest that birds may not be the best models for flight capacity, and that wing structure, overall anatomy, and launch mechanics were very different in pterosaurs. If so, then using birds as models for flight requirements and limitations in pterosaurs could significantly skew the results.

The heart of the arguments of Witton and Habib are the estimates of wingspan and mass suggested previously for pterosaurs. They note that relatively modest difference in wingspan calculations could have dramatic implications for calculations of mass. They state that mass estimates for a pterosaur with a 43 foot wingspan would be almost twice the estimate for a pterosaur with a 33 foot wingspan. Their assessment of the fossil material suggests that no pterosaurs had a wingspan of greater than 33-36 feet.

Likewise, Witton and Habib are critical of the body shape models used by Henderson for Quetzalcoatlus, arguing that his estimates of body size were too large, and were responsible for the very high mass values he obtained. Combined with Witton and Habib’s wingspan estimates, they calculate a body mass for Quetzalcoatlus of about 440 pounds, about one third the value of Henderson.

All of this discussion about wingspans and weights teases us with the question we really want to know—did the largest winged animals ever known actually fly? Could we have looked up into the Mesozoic skies and seen an animal flying overhead with a 34 foot wingspan and weighing as much as a tiger?

The problem, as is often the case in paleontology, is a lack of fossil material. The preserved material of these large pterosaurs is very fragmentary, and this significantly impacts our ability to accurately estimate their overall size and mass. We have in these two studies outlined here two extremes. We need more fossils before we can really know which study is most accurate.

Also, it is likely that birds may not be the best models for pterosaur flight as pointed out by Witton and Habib. Birds do things very differently than bats, our only other modern flying vertebrate, and it is most likely that pterosaurs had unexpected adaptations. For example, Habib (2008) is finding evidence for a vaulting launch in the largest pterosaurs.

Check out this video on the Quadrupedal launch in pterosaurs for an interesting viewpoint.

The largest pterosaurs have not been grounded quite yet.

 

References:

Habib, M.B., 2008. Comparative evidence for quadrupedal launch in pterosaurs. Zitteliana, B28: 159-166.

Henderson, D.M., 2010. Pterosaur body mass estimates from three-dimensional mathematical slicing. Journal of Vertebrate Paleontology, 30(3): 768-785.

Witton, M.P. and Habib, M.B., 2010. On the size and flight diversity of giant pterosaurs, the use of birds as pterosaur analogues and comments on pterosaur flightlessness. PloS One, 5(11): 1-18.

 

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Treating for bedbugs

Bedbugs have been a rising concern for the last two decades. You can read more about the biology of these pesky house bugs here. In this post we will investigate several methods that might help you deal with them.

The first thing to do is to confirm that you have an infestation, and this can be tricky. Bedbugs can live in large numbers near their food source (you), but they are masters at avoiding detection. Since they generally feed at night, they congregate near beds and sleeping areas. Often they hide in headboards, mattresses, baseboards and carpet crevasses, and bedside furniture. Adults are easily identified when seen as they are about 1/8 of an inch long, dark brown in color, and have dark bands across their backs.

Bedbug nymph

Bedbug

Other telltale signs of bedbugs are blood spots in the bedding, fecal spots in the mattress and box springs, shed skins of the bugs, and of course bites on people. The bites of the bedbugs are on exposed skin, often on the extremities, and the can welt up and itch. You may find that some of the welts line up as the bugs might bite several times while going in a straight line.

Once an infestation has been confirmed action is called for. These pesky bugs can be very hard to eradicate. And for many, they cause great stress and anxiety. When you know that you are being fed upon at night you may hate to crawl into bed and sleep. After all, your bed is your place of refuge, and if you are not safe there, nights can become a nightmare.

The process for getting rid of these little suckers (literally) can be a lot of physical work. Start by physically cleaning all the areas around the bed. Wash all bedding in hot water. The heat will kill any bugs and eggs. Take clutter from around the bed, places where the bugs could hide, and heat treat it as well. You cannot simply tie up the stuff in plastic bags as the bugs and their eggs can live for a very long time between feedings. However, I have found it to be effective to place the bags in your car in the hot sun. Repeated heating in a hot car is enough to kill the bugs and eggs.

Pull drawers out of bedside tables and look behind them, cleaning everything in the drawer and behind the drawer meticulously. A vacuum can help. Clean the crevasses around the baseboards and any cracks. Check the box springs carefully, and clean any debris so at least you can see later if there is new activity.

Bugs can also hide in clothing, so you may need to re-wash your entire wardrobe, and then store it in sealed plastic bags to protect from re-infestation. Clothing should be washed and dried in a hot dryer. You may wish to use the commercial machines at a Laundromat. Vacuum your carpets thoroughly. If you have furniture that is infested you may just wish to throw it away. If you do however, be sure to either destroy it or mark it clearly that it is infested so someone else does not carry it home.

Even all this meticulous cleaning will likely not be enough. There are a number of non-chemical treatments that have been suggested. I offer them there for those who would like to avoid the chemicals, but realistically I am not sure how effective they really are.

There are commercially made bed bug traps. Mattress covers might be a good idea. They are designed to trap any bugs inside so they cannot get to you. You would need to also cover the box springs. And while they may trap those already inside, that is likely not the only population you have. Bed post dishes have been suggested. This is where you place the bed legs into a container and put oil or something similar that the bugs cannot cross. The idea is it keeps the bugs from climbing up into the bed in the first place. The problem with this is you have to keep the containers full, and it would only take one time of a blanket falling to the floor, or of you having a bug on a bed slipper and unknowingly giving it a lift to the bed.

Diatomaceous earth has been suggested. The idea here is that the clay will desiccate the bugs, dry them out, and kill them. But direct contact with the bugs is required, and if they are not adequately covered it will have no effect.

Heat does kill the bugs, so steam can be effective. The problem with it is the heat has to be applied very close to the bug itself, and if you cannot get the steam deep into every surface where the bugs might hide, they simply will retreat to a safe place and reemerge.

As much as we all shy away from chemicals, this may be a time to bring out the big guns. I highly recommend a professional exterminator as they are trained in the use and application of the insecticides, and since you will be spraying surfaces that you will come into contact with it is best to get professional help.

I have read (but an not endorsing) that you can effectively spray for the bugs yourself by using a combination of 2 oz of Cy-Kicks-CS (with 6% cyfluthrin) and 1 oz of Martins IGR (1.3% of 2-{1methyl2(4phenoxyphenoxy)ethoxy}pyridine) per gallon of water. These chemicals should be available at a local do-it-yourself store. You will have to repeat the spraying and thorough cleaning of all areas 5 to 7 days after the first treatment as the bugs are not killed instantly but the chemicals inhibits growth and breeding.

Bedbug infestations can be a nightmare. It is best to catch them early. Also, be aware that if you live in a multi-unit dwelling, you cannot just treat one apartment—all of them must be thoroughly dealt with or the bugs will simply move from unit to unit.

So, sleep tight, and don’t let the bedbugs bite—ever again!

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Civilization, War and Climate Change

Over the years there has been growing debate over whether civilization and the environment are integrally linked. Many scientists believe this to be the case, as it appears that several major events in the history of civilization have had an impact on the environment, while major environmental changes have also altered the course of human history. For instance, the Mongolian conquest of the 13th and 14th centuries altered carbon emissions, whereas the Roman Empire flourished during a period of rich summers, and subsequently fell apart during a period of erratic seasons.

Illustration of a Mongol WarriorRecently, scientists have uncovered evidence that suggests the Mongolian conquest of large portions of Asia, the Middle East and Europe may have had an impact on carbon dioxide emissions. When the Mongolians invaded these areas, they often destroyed entire crops, severely affecting the regions’ agriculture. As a result, many farms were abandoned, allowing the forests to take over the land. Thus, during 13th and 14th centuries, these forests were able to grow markedly and absorb huge amounts of carbon dioxide. The study claims that the total decrease in carbon dioxide during this period would be enough to cancel out one year of modern carbon emissions from gasoline. Yet it is important to remember that the Mongolian period of conquest extended across almost two centuries, which means that the actual yearly reductions were relatively insignificant in comparison with our current level of emissions. Nonetheless, the study does show that major events in human society are capable of having an impact in on the environment.

Another study, published in the Feb. 4 issue of Science magazine, also demonstrates the relationship between civilization and the climate. According to the authors of the study, the height of the Roman Empire occurred during a period when the growing season was consistently experiencing optimal conditions. Such conditions provided great economic wealth and the means to uphold the structure of the empire. Thus, the citizens of lands conquered by the empire were much less likely to show dissent.

Conversely, the collapse of the Roman Empire occurred during a period of erratic environmental conditions (perhaps partly due to agricultural overproduction within the empire) that yielded poor or mediocre crops. Without a steady food-supply, the empire faced dissent among its citizens. As the power structure was threatened within, the empire became susceptible to invasion from without and collapsed. In this way, environmental factors defined two of the largest events in Western history: the rise and fall of the Roman Empire.

Jared Diamond expounds upon this idea in his book “Guns, Germs, and Steel.”

According to Diamond, geographical determinism has defined the prosperity of American society. For instance, the vast natural resources of the country spurred our economy tremendously in the early days of the industrial revolution and our physical isolation from the rest of Western society has allowed us to remain prosperous after two world wars. Clearly, much of what makes America dominant is the physical geography that defines it as a nation.

Although the world’s booms and busts have been influenced by environmental factors, ultimately it seems that civilization has had a much larger impact on the environment. In the last 300 years, human population has increased by a factor of 10. Two worldwide wars have been fought and industrial growth has continued to increase in developed and under-developed countries at an unprecedented level. While many of these developments have been beneficial to civilization, the impact on the environment has not been so positive.

One of the negative effects brought about by civilization is the trend of global warming. Since 1750, human beings have steadily increased their production of carbon dioxide, methane, nitrous oxide and other greenhouse gases. These gases are emitted into the atmosphere as by-products of fossil fuel burning, agriculture (in fertilizers and from increased numbers of livestock) and other industrial products, such as refrigerants and aerosols. The greater concentration of these gases in the atmosphere increases the atmosphere’s ability to retain heat radiated from the sun or earth’s surface. Thus, we are experiencing global warming: an increase in the average global temperature. This increase amounts to about 0.74 degrees Celsius. While a difference of less than one degree may seem inconsequential, the average global temperature has only shown an increase of six degrees Celsius since the ice age, which means environmentalists and scientists both have every reason to be concerned about the state of our ecosystem.

By drawing from scientific studies and historical examples, we can clearly see civilization is integrally linked to the environment. Like Genghis Khan, we haven’t undertaken our endeavors with the purpose of changing the environment. Nonetheless, the implementation of large-scale activities such as automobile use, airplane travel, and even war, have significantly impacted the environment and may have very serious consequences for civilization. However, unlike Genghis Khan, we have the scientific knowledge to evaluate and limit the negative consequences of our actions. Hopefully, we will be able to learn from history in time to make a difference.

Author

Ashley Warner is a graduate student working toward her Masters in Conservation Biology. She currently resides in Washington state.


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Action-packed dirt bike games

Racing games sure have come a long way. In the “olden” days, you might be able to find a simple dirt bike game that attempted to simulate the high energy experience of racing around a rough track. Today, there are a lot of choices in games, and they include far more the standard dirt bike to drive and crash up, too.

Here are the features of a couple of the highest rated games available today.

Pure (rating 4 out of 5)

PurePure, by Disney, is predominately an ATV motocross game (PlayStation 3, Xbox, and PC). You are given a lot of flexibility in building your own custom vehicle from the ground up. And you can race across seven of the world’s most dramatic natural environments, modeled after the real places, including Wyoming, New Mexico, and Italy. In all, there are more than 30 tracks to try out.

Reviewers generally like the graphics of this game, and the customization of the vehicles. One negative statement that comes up is the lack of variation in the game play experience, and that it tended to become repetitive, but overall are good value.

MX vs ATV Reflex (rating 4 out of 5)

ReflexA slightly newer release than Pure, MX vs. ATV Reflex (PlayStation 3, Xbox, Nintendo DS, and Sony PSP) adds several different dimensions to the genre. First, there are a wider variety of vehicle classes you can pilot, including ATVs, buggies, motorcycles, and trucks. One of the coolest features I think is the real time terrain deformation, that is, as you and other drivers go around the track, furrows and damage done by the vehicles is preserved for the next lap, making each lap a new challenge as you adjust to changing conditions.

Also, as you make your way through the game you can encounter famous top riders in the sport, and you can test your skill against their digital personas. Another feature that the makers tout is the wreck avoidance system, giving rise to the “reflex” part of the title. As you attempt death-defying tricks, jumps, and feats, the game tells you if you are not pulling out of it in time to land safely. The wreck avoidance system gives you a chance, with quick reflexes, to save yourself at the last second—if you are fast enough.

Motorstorm Pacific Rift (rating 4.5 out of 5)

MotorstormMotorstorm (PlayStation 3) takes this game style to a different level, claiming to be faster, and more brutal than the competition. The game features 8 different vehicle classes (bikes, ATV, buggies, rally cars, racing trucks, mud pluggers, monster trucks, and big rigs). Winning is not the only thing in this game, as you also score points for how you race, and how well you out compete and out crush your opponents.

Unlike the other games that seeks to simulate real-world places, this game’s action takes place on a single Pacific island set aside for the races. But the island is large enough to have four distinct zones, and therefore, four distinct types of racing: air, fire, water, and earth.

Unlike some games, it does feature a split screen view for multi-player action with friends, and it also boasts of real-time track deformation. Action is the name of this game, as it claims to be brutal, dangerous, relentless, and unpredictable. Reviewers rate the experience very highly. The limited platform availability is the only down side of this game, unless of course you have the PlayStation—in which case, you can gloat over your friends.

See also
Fishing games—a sea of options

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Fishing games—a sea of options

Fishing remains a very popular past time for many people. And, there are many reasons that people seek it out, ranging from some low-key family time, solitude on quite waters, the thrill of fighting with another species, to professional and tournament fishers interested in competition.

When you cannot get out on the water, you may be interested in a fishing game to help pass the time, and the range of titles and formats can be overwhelming. There is a tough balance to achieve in fishing games—enough action for the video gamer, and enough simulated fishing to satisfy the fishers, and this explains why there are few fishing games that have been really successful. Here, I will provide comments about a few of the best-reviewed fishing games out there today.

Atlus Pro Fishing Challenge (rating 4 out of 5)

Altus Pro Fishing ChallengeFor simulation games, an older and highly rated game is Atlus Pro Fishing Challenge (for Xbox). With the fishing rod controller, this game provides an in-depth experience, simulating a real fishing trip. The game features 4 photorealistic lakes. You create your avatar and there are many “skins” to select from, including both men and women. You gear up at the tackle shop and head for the water. The game has over 100 pieces of tackle including rods, lines, reels, and lures. As you progress in the game and win tournaments you can unlock optional gear and clothing as a reward.

You select lures, rods, reels, and other equipment and learn about water conditions as to where to find the best fish. Depth, water temperature, and other environmental variables are given for you to find the best holes. One feature that may be a plus or a negative is that the action is all viewed from above water—just like in real life you are not transported to an underwater view of the action. You cast, and trawl, and when a fish bites the real fun begins.

You cannot just reel it in—your line will break or the fish will otherwise get away. Instead, you must “play” the fish, letting it battle you until it fatigues and you can safely bring it aboard, just as in real life. You can even utilize the online gaming experience to visit a virtual lake and interact with other anglers. This is as close to a real in-door fishing experience you are likely to get. 

Rapala Pro Fishing (rating 4 out of 5)


Rapala Pro FishingRapala Pro Fishing (PC, PlayStation 2, PlayStation3, and Nintendo Wii) has also been around for a while, and is generally well reviewed. In contrast to Pro Fishing Challenge, it is slightly more of an arcade experience in that you do not have to fuss as much with all the variables to start fishing, but there are variables to play with. The game features 11 species of fish, 12 localities around the world, and 2 game modes, free and tournament.

You have a fishing buddy in the game that can help by pointing out various tips to improve your experience, such as changing lures and other things that can be a big help. The camera view briefly shows you underwater scenes as fish approach and takes the hook. After that, it is above water views as you fight to land your fish. If you leave too much slack in the line your fish will throw the hook. Keep the line too tight and it could snap.

Rapala Pro Bass Fishing 2010 (rating 4.5 out of 5)

Rapala Pro Bass Fishing 2010One of the newest video fish games on the market is Rapala Pro Bass Fishing 2010 (Nintendo Wii, PlayStation 2 and 3, Xbox, Nintendo DS, and Sony PSP). This game comes in both a standard edition and a rod peripheral bundle edition. The game features over 25 species of trophy fish as well as many lures, boats, and other gear. There are several game modes including free, amateur, pro, and legendary, and head to head, with 4 levels of competitions at each. There are a variety of competitions styles within the game, including heaviest, longest fish, most fish caught in a given period, and so on.

This game boasts of a true tournament structure, with the action presented as a live TV event, including announcers calling the action. Being very new, many reviewers really like how this game makes use of the newest PlayStation move technology.

The game features a lot of different gear, with 49 lures, and extra rods, reels, and boats. Built-in fish-o-pedia will tell you if you have the right lure for the target species you are after. Once hooked, the view shows a split screen view of both above and under-water action. You fight your fish, working to keep it in the center of the screen so it does not snap your line and get away.

Given the diversity of formats available for this game, and the quality of its graphics, I think this is the game I would opt for, all things being equal, if I wanted just one fishing game in my collection.

Fishing Controllers

Of course, a true fishing experience involves a quality fishing controller. Here is a list of several fishing controllers you can get for your system. This section is not comprehensive, and I have not reviewed these controllers, but list them for you as a place to start if you need a controller and will not get one with the game bundle you purchase. Happy fishing!

Naki Bass Champion X Fishing Controller for Xbox

Naki Bass Champion 2 Fishing Controller for PS2

Wii Fishing Rod with Reel for Nintendo Wii

See Also:
Marcum fish finders
Fishing as a pastime for you and your family
Breeding fish in a home aquarium
Action-packed dirt bike games

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