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Archive for June, 2007

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A bit of scribbling just cropped up in New Scientist. Here’s the first 200 words or so:

It’s about some neat research into the way rip currents work – great food for thought during those endless counterproductive paddleouts at your local beachbreak.

It was interesting to write for a straight-ahead magazine like New Scientist. Forget these fanciful Scribble posts, where I get to mosey around in whatever I think is interesting; this story was concerned with explaining What Happened. And I didn’t even get to do all of that in my 1,200 words. Here are some things that had to get left out:

By the way, the above picture of rip currents is all wrong. Here’s something a little closer to reality, according to drifters deployed by Jamie MacMahan and colleagues (thanks, Jamie). White arrows indicate current speed and direction:

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The term “rip current” wasn’t even invented until about 1925, in Science, when some scientists rebelled at the notion of the “undertow myth,” kicking off a flurry of indignant correspondence.

Francis Shepard, of Scripps, pioneered rip current research – taking measurements while dodging set waves in a rowboat.

In the 1960s, other researchers tossed waterlogged whiffleball-like floats into the surf. They tracked where they went using a camera dangling from a helium balloon.

Until this year, even the most intensive rip current studies recorded very few measurements in rip channels themselves. It’s just too dang hard to install a current sensor with a freakin’ rip current whipping past you at 4 knots.

Jamie MacMahan, one of the scientists I wrote about, said six years ago they did manage to install a sensor in a rip channel north of Monterey. It ran on batteries and logged data to a chip to be recovered after 3 weeks or so. They’ve never found it. “As far as we know, it’s still down there, it’s just a lot deeper,” he told me.

MacMahan is cool. Young, already an assistant professor at the Naval Postgraduate School. He’s a little shorter than me, fit but rounded, kind of like a polar bear. Most of the time I talked to him, he had salt water running down his nose. When he’s in the office, he kicks his flip-flops off next to his hard drive. He figured out how to use off-the-shelf GPS for his surf drifters by cruising techie blogs. He invented a way to measure sea floor contours in pounding surf using a depth meter and a jet ski.

The GPS surf drifter was invented by Wilford Schmidt when he was a Ph.D. student at Scripps. He’s now a professor at U. of Puerto Rico in Mayaguez, where he surfs choice Caribbean waves early in the morning. He’s starting to study wave turbulence by installing video cameras in the crystal clear tropical water. He says, kind of gloatingly, that the only reason no one’s done it before is that at the world’s major oceanographic research centers, the water’s just too murky.

Tim Stanton, the other Naval Postgraduate School researcher in the story, studies the other side of rip currents. Where MacMahan’s interested in how the sand shapes the water currents, Stanton’s interested in how the water moves the sand around.

Here’s a classic example of the trials of field research: Stanton’s focus for this year’s field experiment was deploying a super-high precision instrument that measures how much sand is moving in the current, in 1-centimeter slices through the water. He designed the electronics himself and built the instrument to measure continuously for several weeks.

How’d it work? Well, one drawback to studying rip currents is you have to put your instruments in rip currents. The very first day, some kelp got caught up in a rip, recirculated in the eddying flow, and knocked the instrument flat. Last time I saw Stanton, he was planning an expedition for the next low tide to look for any remaining pieces of the instrument.

In the New Scientist article, Ad Reniers is a Dutch modeler who’s a whiz at fluid dynamics. In person, he wore a flaming orange Hawaiian shirt. It was unbuttoned far enough to see his Tecate temporary tattoo. (“Hey, Cinco de Mayo, man.”)

I had an interesting chat with Dr. Edie Gallagher, who studies sand transport at Franklin and Marshall College in Lancaster, Pennsylvania. Standing there in a wetsuit, still dripping wet, she looked at the undulating beach in front of us and said something like, “It’s basically an exact reflection of the waves that strike this beach. The sand that’s here is here because these waves leave it. Anything finer, they carry out. Anything coarser stays up in the rivers.” That, to me, was a whole new way of looking at beaches.

Thanks to all the scientists who helped me write the story.

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Thanks to the pharmaceutical industry, most of us are familiar with the concept of time-release capsules. Our tummies ache and we soothe them – not with a concentrated blast of raw medicine, but with a pill that gently releases its ingredients through the day.

Now picture a 13-mile-wide time-release capsule floating in the Weddell Sea – that nook of water that hides out in the lee of the Antarctic Peninsula. That’s the picture that Ken Smith, of the Monterey Bay Aquarium Research Institute, and his colleagues offered this week in Science Express.

Smith and his team studied a couple of large icebergs as they drifted away from the Frozen Continent. Granted, it doesn’t take eight scientists and an NSF grant to realize that icebergs melt in water. But what Smith found interesting was all the dirt sprinkled throughout the ice. While dirt is pretty unremarkable on land, it gets increasingly rare and precious as you head out to sea. The minerals and nutrients it contains are simply missing from large swaths of ocean water. In this respect, an iceberg is sort of like a humongous Jolly Rancher candy drifting through the sea, slowly distributing its goods.

iceberg_smaller.jpg Smith’s study measured the effect of the added nutrients – evident to more than 2 miles away – and traced them up the food chain. They found more phytoplankton, more krill and more seabirds around their icebergs than in open water. In 4,300 square miles of the Weddell Sea, they counted a thousand more icebergs and calculated they could be spurring productivity in as much as 39% of the Weddell’s waters. When all that fertilization is combined, they suggest, it could have a significant contribution to drawing carbon dioxide out of the atmosphere and sequestering it in the ocean.

Sound familiar? This is a neat illustration of a nearly self-contained ecosystem, the kind of microcosm – like a termite mound, or a tree frog living in a bromeliad plant – that never fails to capture our imagination. That’s why I like the story. And yet, didn’t Science just report something far less optimistic about fertilizing ocean waters and carbon dioxide? Yes, not two months ago, in fact, we learned that most of that carbon – 50% to 80% of it – gets recycled by zooplankton and never makes it to the safety of deep waters.

I suppose it’s hard to blame Smith et al. for not fleshing out their argument. They are, after all, writing in Science, which is so tight on space that it no longer bothers printing study methods (relegating them instead to “supporting online material”). But then, if academia has become so compartmentalized, is it fair to turn around and blame journalists for misrepresenting the broader issue? Their word counts are even stingier (and their syllable counts? forget it).

Science Express, where Smith’s article appeared, is the online-only, rush-publication branch of Science that its editors reserve for the coolest, latest-breaking research. This same week, Science ran two articles about carbon sinks – basically, the question of where all the carbon that doesn’t stay in our atmosphere winds up. One reported that tropical forests do more carbon uptake and northern forests less than we previously thought. The other suggests changing wind patterns in the Southern Ocean have reduced its capacity for soaking up carbon over the last 25 years.

To help Science‘s readership keep all this research straight, David Baker, of the National Center for Atmospheric Research, offered a “Perspective” article summarizing the two papers. But even here, the scope was reined in. The editorial didn’t mention Smith’s article, even though the same publisher ran it the very same week and it broached the very same topic: carbon dioxide uptake in the Southern Ocean

For academia, this is appropriate. Smith and co. didn’t offer any actual data about carbon sequestration, so it’s premature for scientists to talk about it. And yet, which of these various papers should a reporter draw from? As long as scientists drop nuggets of research haphazardly into the literature, we have to expect it to diffuse on its own, slowly and gently, into the ocean of public awareness. So far, climate change seems to have taken some 50 years to acheive an effective dose.

Illustration: Nicolle Rager Fuller, National Science Foundation; photo: Rob Sherlock, MBARI.

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griffon.jpgMore than 100 griffon vultures glided into Belgium this week, some 600 miles north of their breeding grounds in Spain. Taking up residence in an old field, the pack spent the next few days glowering at assorted birders and gawkers. A few got fed up and took off for Holland. On Tuesday, some Belgian environmentalists stopped by with some pig carcasses so the griffons could fuel up for their return flight. And just like that, they left.

The interesting part about the story – above and beyond the simple thrill it must have been to watch a band of feathered Hell’s Angels drop out of the sky unannounced – is the reason being tossed around for the birds’ strange behavior. People think the vultures are starving, getting desperate, and embarking on long flights looking for food.

It’s quite possible. Ever since mad cow disease scared people in 2002, the E.U. has forbidden farmers from leaving dead cattle out on their land to rot. There seems to be little evidence that’s done anything to reduce mad cow disease, but it has made for some very hungry vultures. In addition to kick-starting this vulturine road trip (think Dennis Hopper in Easy Rider), about 100 griffons near Burgos, northern Spain, assembled themselves into a posse last month and took down a perfectly healthy cow and her calf. Yikes.

It sure sounds like a good explanation – perhaps that’s why it crops up in every one of the handful of news reports on the story. And I’m all for vulture survival. But let’s at least wave the scientific method in its general direction. Apparently the E.U. says they’ve given Spanish farmers special dispensation to leave carcasses out, but few farmers actually do. And anyway, why would vultures fly northward, farther into the E.U., to find a meal?

I know, I know, vultures can’t be expected to keep up with politics, but north puts them out of the limits of their historical range, and there probably is some reason why they weren’t in northern Europe already. For an animal that has some degree of latitudinal awareness when it chooses a place to live, it seems a strange time to begin ignoring it.

I think what’s interesting here is not whether the mad-cow carcass ban actually causes vulture rampages. It’s that the hypothesis is attractive enough that it can bypass the scientific process and crop up in the news more or less as fact. (Spiegel Online, the first link in this post, does offer the E.U.’s alternative explanation, but much lower down in the story.) News space is tight, and a couple of shorter articles mentioned only the mad-cow explanation.  Read a couple of these articles in a row, and you (think you) know all you need to know about mad cows, carcasses and vulture conservation. Sound familiar?

(It seems almost unbelievable that there are no videos yet of the birds on YouTube. Perhaps I just don’t know how to search for “Brussels vultures” in Flemish, Dutch or French. I did at least learn that a “Brussels griffon” is a kind of small yappy dog that certain people like to dress up and feature in movies.)

Image: by Rev. Francis Orphen Morris, 1891, via birdcheck

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If you’re interested, check out the slimmed-down set of 78 photos from our recent road trip. Clouds, rocks, self-taken group shots, and mustaches galore.

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I’m sorry to report that yesterday’s post about disease-causing organisms in ocean water is only half the story: there’s also disease-causing chemicals out there, too.

Now I realize that in the back of pretty much everyone’s minds, there’s the knowledge that ocean water contains nasty chemicals. So I won’t take a lot of your time here – I’ll just remind you of a few names to keep track of.

Lead and mercury aside, most can be neatly tied up in one or a few generic terms: organochlorines, polyhalogenated aromatic hydrocarbons, polychlorinated biphenyls. Big names like DDT, dioxin, and PCBs fit into one or more of those categories. But as with microbes, it’s pretty difficult to keep the subcategories straight: what’s the difference between PCDD, PCDF, PBDE, PCN, or the murky-sounding DBP, or “chlorination disinfection byproducts”? HFINo***

But again, we can count ourselves lucky to have people who do know the difference – and who are getting pretty good at measuring it. A couple of recent studies did the math all the way through to estimating roughly how much of these chemicals a typical seafood-enjoyer ingests.

For instance, a typical Catalonian hombre might eat 1.53 nanograms of polychlorinated naphthalenes (PCN) in a day – more if he eats a lot of salmon or sole and less if he prefers shrimp or cuttlefish. A Belgian study analyzed “market baskets,” comparing the chemical contamination of many typical foods. Fish topped the list of most contaminated, with PBDE levels nearly twice as high as the second place (dairy and eggs). Fast food was a distant third, with steak and chicken breast registering even safer. The authors noted one exceptional salmon filet that raised the bar, coming in with a PBDE concentration five times the seafood average and nearly an order of magnitude above second place.

In eastern U.S. fish markets, you can find more than 20 times as much PCB and PBDE in wild bluefish as you can in farmed salmon (and wild salmon had only half as much of these chemicals as farmed salmon).

That may sound like yet another plug for wild salmon, but then again, consider the wildness of your salmon’s homeland. Does it cavort in essentially urban waters like Portland’s Columbia River or the Nisqually estuary south of Seattle? Because if it does, it’s likely to pick up PCBs, DDTs and PAHs from runoff.

Young chinook salmon heading out to sea from the Duwamish Estuary, the Columbia River and Yaquina Bay had PCB levels in NOAA fisheries’ red zone – above 2,400 nanograms per gram of fat. (I imagine it has been argued that as these salmon grow up in relatively pure open ocean waters, those levels will come back down. But still.)

It’s also curious that coho salmon sampled from the same locations as the chinooks were consistently less contaminated – by factors of 2-5. Sounds like a mystery for the ecologists to solve.

There’s still the question of how much and how steady of a diet of these compounds one needs before cancer sets in. Part of the trouble lies in toxicity differences among the many compounds (called congeners) that are contained within the categories I listed at the top of this increasingly glum post. Unfortunately, for almost every one of those thousands of congeners, we just don’t know specific toxicity levels.

Well, if it’s any comfort to you, all those omega-III fatty acids are still really good for you.

Image: Alaska’s Wildlife. Thanks to SeaWeb for the tips.

***HFINo = HellifIknow

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Reports of the declining state of the world’s fisheries aside, there’s a whole new frontier opening up in the world of ocean life.

They’re called “emerging diseases”: small, aggressive specks of life working like hell to get noticed in a mostly hostile environment. Kind of like “emerging indie-rock,” just less noisy and more likely to stick around.

Many of the diseases aren’t exactly new, they’re just cropping up in new places as a side-effect of how good we are at detecting tiny things. And while your best chance of catching a nasty marine disease probably still involves a raw oyster, every new virus or bacterium that shows up in a water sample is another possible period of porcelain worship for you. And, joking aside, death by diarrhoea happens some 1.8 million times per year, with 90% of its victims younger than 5.

Still, you don’t read a lot about the culprits, at least in part because once you get down to the level of microscopic things there are few terms familiar enough for a reader to hang onto. I mean, the bright and ferociously well-informed Scribble readership can probably keep their bacteria straight from their viruses, but is that true for USA Today’s? Even for our lofty selves, the smugness evaporates as soon as we go one level down: Where would you file Hepatitis E? the polyomaviruses? the adenoviruses? The rotaviruses? The enterococcans? The nematodes? Which of those contain DNA? (And no, the answer is not all of them.)

The pattern with most of these emerging diseases is that they’ve become better at surviving in places we assume are unlivable. Salt water is a great example – it’s famously antiseptic and has long been considered a great receptacle for treated and untreated wastewater. But several bits of biological fine print seem to have created some loopholes. With more humans in the world flocking to the same number of beaches, more contaminants are washing directly into the water – where odds are they spend less time combating the elements before encountering another bather. One more reason to surf alone.

A University of Miami study put 10 normal-looking, clean adults with good jobs into a kiddie pool filled with 4,700 liters of sea water. After 15 minutes, they found that on average, each person had contributed 600,000 enterococcus (indicative of fecal contamination) and 6 million staphylococcus (skin infection) colony-forming units. Each person. Finally I understand what those signs mean by “Please shower before bathing.”

Cooperation is another way microbes confound us. The bacterium that causes cholera, Vibrio cholerae, is not especially dangerous to people until it winds up in the gut of a little zooplankton called a copepod. Then it becomes one of the most dangerous of all waterborne illnesses.

The cholera-copepod link is pretty well known – Rita Colwell helped figure it out and soon found that Bangladeshi women could use folded sari cloth to filter out copepods from their drinking water. The Vibrio bacteria passed straight through the filter, but cholera infection still dropped by about 80% because the copepods were gone.

Alliances like this seem to be another stratagem pathogens have for staying alive long enough to do us in. Last year I got to write about Rebecca Gast‘s work isolating Legionella and other bacteria and amoeba from sea water. It appeared that shortly after riding out of the sewer outfall pipe, some bacteria managed to get themselves ingested by amoeba. They were quite happy with the arrangement, as the insides of the amoeba were more hospitable than the surrounding sea water. As time goes on, the colonies inside the amoeba grow in number and virulence.

Enter large, sunburned man bobbing in inflatable seahorse ring, slurping from warm can of beer. In the world of emerging diseases, that’s a picture that’s not going to get any prettier.

A single table of contents in a single journal like Water Research offers enough material to go on and on. But I don’t even know what most of these things are – I don’t even know what they sort of are. I guess we can be thankful that, like so much of the rest of science, there are people making their careers solving problems we may never hear of. Ignorance is bliss. So far, anyway.

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Brother Dodges Sniper

yellowribbon.jpg My brother Owen was hit in the head by a sniper bullet yesterday in Baghdad. He’s uninjured, through some incredible luck, or perhaps just leftover grace from one of his myriad religions (ranging from Christianity to Harley-Davidsons). The bullet pierced his hi-tech Army headphones, ripped through the kevlar lining of his helmet, and… stopped. At first he thought he’d been hit by a large and well-aimed rock.

He’s been in Iraq for a year. Coincidentally, yesterday is the day he would have been climbing into a C-130 and heading home to his wife, dog and margarita blender, had his tour not been extended as part of The Surge.

So I’m reclaiming the yellow ribbon. On this post, at least, it no longer means that somehow, our troops wound up in a war, and it’s our duty to support them.

3,500 soldiers have died in Iraq and each one of them is President Bush’s fault. His fault for making up the reasons to go to war, his fault for not planning for an occupation, his fault for lacking the imagination to think of another course, his fault for not having the basic American guts to admit he was wrong, his fault for thinking that cocky = capable, his fault for thinking democracy could be pushed like religion in a revival tent.

His fault for running for re-election on a yellow ribbon, then hiding behind it until 2008.

Much is made of how our armed forces are the best-equipped, best-trained fighting force the world has ever seen. But even the Titanic sank when someone steered it straight into an iceberg. This is an amateurishly conceived war led by a president who is totally out of his depth and clung to by politicians who can’t imagine any disaster larger than the loss of their own jobs.

Periodically, Owen writes about daily life for the Sandbox under the pseudonym Sgt. Roy Batty.  His reports are more vivid and more enlightening than anything on TV. Read one here, and e-mail a word of support to sgtroybatty at yahoo dot com. The troops can hear us, even if their leaders can’t.

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Happy World Ocean day – at least, to all of you in the western hemisphere, since by coincidence I am writing this at midnight Greenwich Mean Time, meaning that for the whole eastern hemisphere it’s already tomorrow. Weird.

The good ocean advocates over at Blogfish organized a blog carnival to celebrate the day. Lead blogfish Mark Powell (no relation, but there’s more about him here) compiled links and summaries for a few dozen thoughtful ocean bloggers. He ends with a fitting conclusion: Who knew there were so many of us?

Or that we were so good? A fascinating post at Zooillogix on creeping crinoids shows something that looks sort of a like a zombie underwater sunflower tiptoeing across the seafloor in a totally Tim Burtonish way. I’d say it even beats out the walking octopus from a few years ago.

The Surfrider Foundation puts in a good word for menhaden, those teeny schooling fish that people have been hauling out from Chesapeake Bay and elsewhere on the East Coast for decades.

Oceana has been filming French fishermen illegally using drift nets, and apparently the fishermen recently attempted a raid to confiscate the evidence.  Didn’t work.

Pharyngula even gets into the game with some background on how an octopus can change color so fast. Not to be outdone, the Daily Kos has about 1,000 words on how pearls form (Hint: they’re not the tears of angels, nor are they the result of an oyster swallowing a dewdrop. Interestingly, they also don’t come from a grain of sand.)

The blog links just keep coming: Gulf Restoration Network snuck one into the comments section, correcting an absence of news from the Gulf of Mexico. (The Scribbler spent a good portion of high school a small distance above the Gulf of Mexico, hanging off the side of a catamaran.)

And if you’re too on-the-go to sit still for all this silliness, take your ocean blog with you at cephalopodcast. It is a carnival, after all.

Now, to find the frozen fried Twinkies.

Carnival badge: cephalopodcast

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heddha.jpg Pudgy, snub-nosed, totally cute and only slightly prickly. Can there possibly be such a thing as too many hedgehogs? Apparently, the answer is yes, at least for small islands like the Hebrides west of Scotland, where hedgehogs only recently arrived.

And yes, this story is filed under climate change because the author traces a possible looming hedgehog bonanza as one nightmarish offshoot of the coming global warming. Now, I don’t normally like to poke fun at global warming alarmists – I mean, what’s alarmist about standing in a burning building and pulling the fire alarm? But he may be stretching things a bit here.

Nevertheless, introduced hedgehogs don’t confine themselves to politely rummaging under privet bushes. On tiny islands like South Uist they barge around like they own the place, cracking shorebird eggs with their little nubbin teeth and sucking out the contents. Their natural predators, foxes and badgers, are absent from the island, so apart from the odd death by recklessly driven Mini or wobbly hedgehog syndrome, there’s no stopping them.

A Journal of Zoology paper by the (aptly named) Digger Jackson estimated about 2,700 adult hedgehogs on the island and found up to 32 per square kilometer in some pastures. Come springtime, all that concentrated adorableness creates quite a bustle in your hedgerow, as adults churn out some 3,000 youngsters each year.

Most young die over the long, harsh North Atlantic winter, rendering the hedgehog population something of an annual crop, like arugula. But the Hebrides have warmed at an average rate of 0.06 degrees C per year over the last 20 years. With milder winters, earlier springs and warm, insect-filled summers, the author reports, hedgehog populations could be on the rise.

Image: hedgehog coffee mug by Judie Peters, on cafepress

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Central Oregon’s Painted Hills, in the John Day Fossil Beds national monument.

The road trip is over. We wound 2,500 miles onto the odometer, took 414 photos, visited 15 friends, crossed the continental divide 9 times, and gawped at 13 volcanoes, 7 sandhill cranes, 4 snakes (50 percent rattlesnake), 3 eagles, 2 harlequin ducks and 1 sopping wet beaver.

We rolled back into town Sunday afternoon to find a 4 foot south swell marching against the cliffs on the west side. Tragically I was in no shape to surf. A freak accident involving a carnivorous Oregon hearthstone had left my pinky toe the color of a western sunset and feeling roughly the size of the U.S.S. Macon. I would post a picture but some of you have probably eaten recently.

We consoled ourselves at Los Pericos, a new Santa Cruz taqueria that has developed some sort of proprietary technology for cooking carnitas. They stew the meat in pepper and bay leaves, then shred it and press it against a hot griddle till the frayed edges are brown and crisp as breakfast potatoes. Serve it with nachos made from thick corn tortillas fried that day, add a tamarindo Jarritos, and it’s Welcome to Santa Cruz!

Taquerias are a cutthroat market in Santa Cruz, and Los Pericos occupies an ill-fated location that has seen at least five establishments close their doors in the last four years. But the periquenos really want their restaurant to make it. They’ve posted signs with large letters offering vegetarian options and student discounts. Menudo, served on weekends, draws the true-believers.

Once you’re inside, the scruffy proprietors make special trips to bring you disposable plastic forks and napkins. If at any moment they find you chipless, they hurry over, gesturing at the makeshift salsa cooler with a grand sweep of the arm. Then they go back to the grill to assemble your mountain of carnitas. I hear the rest of their menu is good, too, and I plan to explore it someday. But not just yet.

In my hazy post-carnitas aftermath, I discovered that President Bush has flip-flopped on climate change – I suppose we should be grateful for small (and hopelessly tardy) mercies. The New York Times realized that water quality at SoCal surf spots is sometimes yucky. And someone posted an unbelievable amateur wildlife clip from Kruger National Park in South Africa. All I can say is it’s only 8 minutes and it involves some lionesses, some water buffalo, plus a cameo or two. Watch the whole thing and don’t fast forward or you’ll miss the shockers (thanks, Andy).

Finally, Jenn, here’s a Mt. St. Helens shot for you. I’m not sure our pilot knew there was such a thing as a flyover advisory. There’ll be more trip pictures up on Flickr just as soon as I remember my password.

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A warm thanks to everyone who provided us with beds, beers, fun times, happy pets, good music, and large hunks of roasted animal during the road trip.

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