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July 13th, 2009
topteddy
 | 08:15 pm
It's hard to miss the focus on bisphenol A (BPA)—we know it leeches from bottles and cans into beverages and foods. But a new study out of the Harvard School of Public Health is the first to make a direct link between urinary BPA levels and drinking from polycarbonate bottles, a material widely used for baby bottles and drinking containers.
The results of the study are unsettling:
After just one week of drinking all cold beverages from polycarbonate bottles, BPA concentrations in the participants' urine increased by an astounding 69 percent, from 1.3 μg/L creatinine before using the bottles, to 2.1 μg/L after using the polycarbonate bottles for a week. A 2008 Centers for Disease Control study listed the national geometric urinary BPA mean at 2.6 μg/L.
These findings offer a key piece of evidence in the search for the health impact of BPA. The Harvard doctoral student who led the research, Jenny Carwile, explains:
While previous studies have demonstrated that BPA is linked to adverse health effects, this study fills in a missing piece of the puzzle—whether or not polycarbonate plastic bottles are an important contributor to the amount of BPA in the body.
It is important to note that the study was not looking at how much BPA accumulates in the body, but at the amount of BPA that makes its way through the body before it is expelled.
Critics may automatically think the BPA detected could be linked to other sources of BPA exposure, but it's unlikely.
The study's 77 participants—all students at Harvard—followed a generally uniform routine, week over week, including eating in campus dining halls.
The participants also went through a week-long "washout" phase in which they drank all cold beverages from reusable metal bottles, in this case, new Kleen Kanteen bottles, which are BPA-free. Orally administered BPA has a half-life of about six hours, and it is eliminated from the body after about 24 hours, so a week-long cleanse was deemed sufficient.
The following week, participants drank all cold beverages from the polycarbonate bottles they were provided with. The bottles used in the study were new Nalgene Lexan narrow mouth and Nalgene Lexan wide mouth bottles.
Fruit juices, carbonated beverages and drinks such as Gatorade can increase BPA leeching, but the study did not place restrictions on which beverages students could drink from the bottle. Participants were, however, instructed not to fill their containers with water from coolers placed in the dining halls.
It is also important to note that participants did not drink hot beverages from the bottles and they didn't wash their bottles in a dishwasher, as many people do. Heat from either of these sources could have yielded an even greater increase in urinary BPA, says Karin B. Michels, associate professor of epidemiology at the Harvard School of Public Health and Harvard Medical School and senior author of the study:
If you heat those bottles, as is the case with baby bottles, we would expect the levels to be considerably higher. This would be of concern since infants may be particularly susceptible to BPA's endocrine-disrupting potential.
Each participant provided urine samples on two of the last three days at the end of each week in order to prevent unusually high or low levels from affecting the results.
BPA Bans in Baby and/or Infant Products
With concern over the health impacts on infants and toddlers, governments at all levels have moved toward banning BPA in food-related products geared at infants and toddlers. The areas currently banning BPA include:
Minnesota
Chicago
Suffolk County, NY
Canada
Similar laws are being considered in California and Connecticut. And according to Renee Sharp, the director of the Environmental Working Group's California office, sweeping change across the country is necessary:
These astonishing results should be a clarion call to lawmakers and public health officials that babies are being exposed to BPA, and at levels that could likely have an impact on their development.
But what about older kids and adults? Should we accept BPA exposure as something we just have to deal with—or go to great lengths to avoid? If nothing else this study shows BPA levels in adults should also be a cause for concern.
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maradydd
 | 03:10 am
Okay, ![[info]](http://l-stat.livejournal.com/img/userinfo.gif) tdj, I may be going to bed angry, but I got a great belly laugh in from the following, linked from one of the comments in the post about Dembski:
And now I sleep.
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maradydd
 | 02:22 am
By way of Pharyngula, apparently the creationists are starting to abuse information theory, not just physics, in their tortured attempts to justify their doctrine.
Of course, you understand, this means war.
ETA: /me reads the comments. Oh. Apparently creationists reject Claude Shannon's work on information theory. Infidels. They shall be first against the wall when the revolution comes.
One thing that I will never understand is why creationists believe that an omniscient God is bad at math.
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maradydd
| 02:25 pm - Progress report
Chording glove pattern prototype, version 1, three fingers and a thumb left to knit:
I am making this up as I go along, thus there are a few irregularities that I will correct in the next version when I take my notes and turn them into a proper pattern. I realized halfway up the index finger that I'd failed to knit a solid line up the thumb side (for mounting the thumb switches) like I'd planned to, and that ugly-looking line right across the palm was an experiment that didn't quite work out and that I couldn't be arsed to go back and fix. (The fishnet pattern is made by knitting two stitches together, then making a hole by bringing the yarn to the front, over and over again. The cool spirally pattern comes from having each row of holes offset from the next by one stitch, which was obligatory when I was making increases for the thumb; I forgot to alternate when I started going up for the thumb side of the palm.)
All in all, though, I'm quite happy with how it's turning out, especially since a couple of experiments succeeded -- you can rib lace after all! -- and some things that I was worried would look stupid, like the solid fingertips (for stability, and to have a place to anchor the switches), look okay after all. Since this is an attempt to figure out a pattern, I'm making this out of plain cotton, and will wire it up by sewing 30ga wire through the knit stitches (the thicker "lines" that you see on the glove), but I still want to figure out a way to work the wiring into the pattern itself, because it will look cooler and I am stubborn like that.
Barring anything weird happening, I should have the complete standalone USB keyboard glove working sometime this week. I have my wire-wrap sockets now, and have soldered in half of the discrete components (the ones I had spares of, by way of a test run); I'm going to hold off moving the rest of the circuit from the breadboard until I have the glove finished and the switches mounted and wired, but the actual wiring-up shouldn't take more than an hour or two.
I'm kind of tempted to set up an Etsy shop and sell these, though I'm not sure how much would be a fair price. The actual knitting probably takes about ten hours (spread out over a few days, since my hands get sore quickly), and the soldering goes fast; the parts are less than $20 total. Any thoughts? Would you buy one?
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July 11th, 2009
maradydd
| 10:50 pm - My Saturday evening
A little cafe, lined with books and magazines; a table in the garden next to a tree-shaded trampoline; a small carafe of French wine and a volume of Chesterton.
It's a good one, this life is.
Current Mood: ![[mood icon]](http://l-stat.livejournal.com/img/mood/bitospud/courier/white/happy.gif) pleased
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July 10th, 2009
July 9th, 2009
galoototron
 | 09:03 pm - Shoe rack: Side frame pieces
I'm in the process of making a shoe rack. It will basically be two side frames with three shelves, all done with mortise-and-tenon joints. I have most of the wood dimensioned, and have the boards for one of the sides cut to length now:
There are going to be quite a lot of mortise-and-tenon joints in this project. I've been practicing, and am getting much better. The fun part is that I'm no longer using the "drill and chop out" method of making the mortise. Now that I have no more downstairs neighbors, I've just been chopping the whole thing out with a chisel. It's noisy and destructive and a lot faster than fooling around with the drills.
This wood is some rather cheap mystery softwood. These boards have a lot of knots in them; in fact, they're downright tragic if you look at them whole. However, if you buy 10- and 12-inch widths, you get a lot of sections that have clear wood, and you can get cuts that are quartersawn in this way. This is a pretty common trick with softwoods.
The growth rings are very closely packed in some of these boards, but it's still a rather soft wood, somewhere around the toughness of yellow-poplar (tuliptree). It's always kind of tricky to make joints in wood like this, but I must admit that there's a bit of a charge when you succeed.
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bramcohen
 | 03:24 pm - Someone at Mozilla Foundation needs to be fired
Somebody at Mozilla decided they need lots of 'true' random numbers.
My patience for this subject completely ran out about five years ago, so this post is going to show a complete lack of diplomacy. I would like to emphasize, in advance, that this is my honest, reasoned opinion, not said in anger, and that if you ask my opinion again in the future I'll say the exact same thing.
Once a computer has collected a small number of 'true' random bits (maybe it's 128, maybe it's 256, but regardless it's small) there's no need whatsoever for it to block on collecting more 'random' numbers. A pseudorandom number generator based on AES will be able to generate random numbers based on that seed until the end of the universe and noone constrained by the laws of physics and math will ever be able to tell the difference between that and 'true' random numbers. This is extremely well established cryptography. To require 'true' random numbers is, to use an apt analogy, wankery. It does not, and cannot, do anything to improve security, and it mostly just causes huge amounts of pain. It is (and I repeat myself, because I have a hunch people will think I'm glossing over some nuance here) of no benefit whatsoever.
My advice to the Mozilla foundation (and again, this is my reasoned opinion, not said in anger, and I won't be changing my mind later): find out who was responsible for this policy of requiring lots of 'true' random numbers, and fire them. Fire them today. They have demonstrated gross incompetence, a total lack of understanding of the very most basic concepts in security.
Some people might think that if I knew more about who was behind this and what their specific motivations are, then that might change my mind. That is incorrect. The security field is filled with people who to non-experts seem very impressive and knowledgeable, especially when they're advocating, and even moreso demanding, very painful and difficult things in the name of security. Most of these people are frauds. I have had it with paying homage to the concept of impartiality when discussing these peoples's opinions. If someone spouts a bunch of technical mumbo-jumbo to bring the conversation to a place which a lay person has trouble understanding, then they may be able to make the argument be based on pure rhetoric, but gross incompetence is still gross incompetence, and despite having found an effective way to bullshit their way through, they're still wrong.
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maradydd
| 10:50 pm - Behold my wrist-mounted USB hub
Seven ports! I need to make a really short USB cable so that I can hook the chording glove up to it.
Four on the inside, three on the outside. USB-mini in the back, optional power supply.
The wristband is a padded velcro thingy that the company that a guy I know works for ordered by mistake. Normally, a smaller beige plastic holder for a barcode scanner velcros onto it; I took the velcro off the plastic thingy and put it on the hub.
My original plan was to get one of those four-port unpowered jobs, mount it in the original plastic housing, and also add slots for SD cards. I may still do that, since the guy has lots of these wristbands available. This approach means less work to do with a Dremel, but I like the idea of storage on the go. Perhaps one for each wrist, to support keyboard and mouse. (Hey, if I ever don't feel like chording but have the rig set up anyway, I can just plug an ordinary USB keyboard into my wrist!)
If I do make a custom wrist-mount, I might go all out and make a PCB for it using this approach.
ETA: Three hours in, I'm still wearing it comfortably, which is impressive for me, since I usually fidget like crazy with bracelets, watches and things like that. I did flip it to the inside of my wrist, because I realised that the titanium bracers that Chris++ is making for the sleeves of my leather longcoat will go on the outside of my arms, leaving no room for an outward-facing hub, but I think it will fit okay on the inside. Worst-case scenario, the velcro straps are long enough that if I have to, I can wear the hub on my bicep. Time to get one of those retractable USB-A/USB-mini-B cables, the clicky kind.
Current Mood: ![[mood icon]](http://l-stat.livejournal.com/img/mood/bitospud/courier/white/busy.gif) busy
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maradydd
| 04:49 pm - Photo meme
Snagged from michiexile.
1.Take a picture of yourself right now.
2.Don’t change your clothes, don’t fix your hair…just take a picture.
3.Post that picture with NO editing.
4.Post these instructions with your picture.
Me and my Arduino NG, with the accelerometer I just rigged up to it.
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July 8th, 2009
galoototron
| 07:32 pm - Various handles and knobs
I'm in the process of varnishing four saw handles, a plane tote, and a plane knob. Here are half of the pieces.
As usual, I'm not being terribly speedy here. It's been seven months since I started working on that tenon saw handle in the center. Things happen but I like to think that sooner or later, I get back to this stuff. (Especially since I've had the saw blade sharpened almost since I started on the handle and it's otherwise ready to go.)
The larger hand saw handle in the rear is for a Disston D-8 that will become one of my new rip saws, somewhere at around 7TPI. This will be in addition to a No. 7 (I think) that's going to be a larger 4.5TPI rip saw. The handle for that one is also in this batch, thankfully. Both of these handles were glopped over with some awful green paint that I needed to strip before the refinishing process started. What is it with the green paint?
The initial finish on these two handles was a mix of "colonial maple" stain, some satin polyurethane, and tung oil, for an oil/varnish blend (this makes the rays in the beech look nice). After a few coats of that, I'm now putting on satin polyurethane. I like the way that a top coat of polyurethane feels on the other handles I've done (as opposed to alkyd varnish and oil/varnish blends), and it seems to hold up better. It takes a little more effort to get polyurethane to look decent, but it's not that bad.
I think I need one or two more coats on the handles.
The knob is from a Millers Falls #22 jointer plane that's been waiting for restoration. I did not use the oil/varnish blend on this (or its accompanying tote), because the ray structure in this tropical wood did not seem worth bringing out. I may be done with the plane parts; I'll evaluate that later.
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galoototron
| 09:48 am - Shooting board
I made a shooting board a couple of weeks ago. As with the bench hook, I don't know why I did not do this earlier.
As it turns out, there's a repeating pattern of things I don't know here. I have no idea why I dovetailed the lip onto the front. I did this on the bench hook, too. It didn't take long and it wasn't hard, but why? I also don't know why I decided to do two little pieces for the front lip instead of one big piece.
The Veritas low-angle block plane works fine for shooting stuff of this width. You could use a low-angle jack plane for this, too. But I now see why people like their miter planes. I don't really see myself spending so much cash on one of those for this purpose, though.
I need to make a rack for my chisels and small saws. The bench is a mess.
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July 7th, 2009
bramcohen
| 11:30 am - Ludology in City of Heroes
City of Heroes has had some interesting issues with its gameplay, involving a character named Twixt using some tactics which made everybody hate him.
Several years ago I happened to be seated next to the designer of City of Heroes at an event where he won something. He was a pudgy guy, wearing big round glasses, with a white city of heroes t-shirt and a blue cape on. We got into a conversation about his game, and I asked what it was that made it compelling, and he said that it's every kid's fantasy of being a superhero, and it was very obvious that he'd based the game's design on his own. I asked him if City of Heroes is compelling as a pure abstract game, and the interesting response was that he didn't understand the question. After a few minutes of conversation he got what I was asking, and his answer, which really perplexed me at the time, was that it was a good question, but he didn't know.
Consider a game with the following semantics: You sit, unmoving, for two hours, with no user feedback, no buttons to push, nothing, completely passive, while the game plays out in front of you, exactly the same way as it would for anybody else. This sounds like a terrible game, but it's exactly what movies are, and movies are very popular and get little criticism that they're terrible games.
The Twixt problem was caused not so much by any one person behaving unreasonably as the game engine having a problem. There's a battle tactic which is quite effective but has the effect of wiping out an enemy without even giving them a chance to play, making it not much fun for them and it doesn't even get much credit for you. Because City of Heroes is more fantasy than game, players have a convention of not using this tactic, because that maximizes the fun of play. This is done at the expense of an individual's success taking the game as a sport, but since the game isn't a sport, people don't worry about that too much. Real sports don't involve dressing up as superheroes (except for figure skating, but that isn't a real sport). What really should be done is that the rules should be modified so that the particular tactic isn't so nasty. It's a general rule of game design that all players should get a chance to play and have fun, even if they aren't very good, and tactics which allow a better player to win without the weaker player even having a chance to try to retaliate are no fun.
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maradydd
| 01:15 am - Brief weekend update
A three-day-long rave. In a field full of windmills. With an absinthe bar. Cool art; music so good that I frequently could not convince myself to leave the dance floor; truly excellent conversations about evolutionary psychology, game theory as applied to intentional communities, chemotaxis and other forms of animal communication (did you know bees' dances have regional dialects? I didn't until Sunday), and emergent network behaviours at the molecular, cellular, and human scales. I spent a good chunk of the time uncertain where my boots were and mostly unconcerned about that fact; I also lost my pants for a day and a half straight, though not the ones I was wearing at the time and not for any particularly exciting reason, but hey, that makes a good line, doesn't it? (Works better for "No shit, there I was" than for "So, there was this girl...", but hey, you can't win 'em all.)
More details later. At the moment I'm going to go soak the grime off of myself, see if a warm bath will unwind these knots in my shoulders, and slather Vitamin E cream all over the ridiculous-looking asymmetric sunburn that is my shoulders and upper back. (Note to self: do not fall asleep in full sun while wearing a tank top ever again.)
Current Mood: satisfied
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July 6th, 2009
bramcohen
| 04:07 pm - Bandwidth fundamentals
A random person asks about something they read on Wikipedia:
Example from wiki below:
http://en.wikipedia.org/wiki/Bram_Cohen
quote from site:
MojoNation allows people to break up confidential files into encrypted chunks and distribute those pieces on computers also running the software. If someone wanted to download a copy of this encrypted file, he would have to download it simultaneously from many computers. This concept, Cohen thought, was perfect for a file sharing program, since programs like KaZaA take a long time to download a large file because the file is (usually) coming from one source (or "peer"). Cohen designed BitTorrent to be able to download files from many different sources, thus speeding up the download time, especially for users with faster download than upload speeds. Thus, the more popular a file is, the faster a user will be able to download it, since many people will be downloading it at the same time, and these people will also be uploading the data to other users.
This explanation was lifted from an actual new article, which doesn't necessarily mean it's true. In fact, it's somewhere between grossly misleading and wrong. There's a classic fallacy because if one person stands up during a concert they get a better view, then if everybody stood up during a concert they'd all get a better view. This is of course is not true - they wind up slightly worse off by all standing, because they all compete with each other for a view. The same thing happens with downloading from a server. In general, web servers will give about the same rate to every client downloading from them, so if you open many more connections than everybody else you get a greater proportion of the bandwidth and hence a better rate. But you do so simply by taking bandwidth from other downloaders. The overall supply of upload is unchange, it's simply being shuffled around. If everybody does the same thing it results in overall slightly worse performance and you're basically back where you started, but with a bunch of headaches tacked on.
On the internet, the formula is bytes downloaded = bytes uploaded. It's that simple.
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bramcohen
| 02:50 pm - The Uncanny Cube
From deep in the uncanny valley of the Rubik's Cube, it's the Uncanny Cube. At first blush this appears to be a slight variant, but it is quite profoundly and perversely different.
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paisleychick
 | 10:26 am - Elections and the Flu
Legislative elections were held a week ago Sunday. The city was more shutdown than normal for Sundays. You couldn't buy alcohol until 21:00 hrs - a couple of hours after the polls closed. I took the 88 bus to La Matanza, once again going to the province of Buenos Aires to take photos. A friend was working the polls and he said that it should be okay for me to take photos of people voting. The bus started five blocks from our apartment and dropped me off about six blocks from the school. The hour and a bit ride went without incident as per usual on the buses here.
Upon arriving at the school, I walked in and upstairs and took some photos looking down on the crowds and of people voting. I didn't get very far before an official came up to me with her clipboard and said it was against electoral code to take photos inside. As she was accompanied by a cop and also really nice about it all, I asked her if I could take photos outside and she said of course. Always easier to ask forgiveness than permission when shooting, but still, a bummer. I left without saying goodbye as my friend was busy and I had to go. As I have been making an effort to walk at least an hour a day, I walked back to "downtown" which was about 1 hr and 15 mins walk away. I was glad to get the exercise, see the town and also I got the best shot of the day, a torn campaign poster.
I haven't been paying very close attention to the news, but I have been trying to loosely follow the elections. They were congressional elections and the big news grabber was that Nestor Kirchner, the former president and husband of the current president, Christina Fernandez Kirchner, was running in the province of Buenos Aires. He lost. In fact the Kirchners took a beating and lost control of congress. There were rumours that they would leave the presidency if that happened and that chaos would break out. All was calm this past week on the politics front, at least from the point of view of the streets not being a mess.
What hasn't been calm is all the hyps about GRIPE A! OMG we're all gonna die!!!! Not really, or at least not now, but people are freaking out. Schools have been closed for a month as of last week. I'm just going about my normal routine and just washing my hands and using alcohol gel a lot more often. I see a lot of people with surgical masks and scarves around their noses & mouths out in the streets and on the buses, etc. They are useless, but make people feel better, much like the security theater at the airports. They don't protect the wearer from infection. They only prevent a sick person from infecting others as the masks are nowhere near airtight. Argentina is third in the world with the number of deaths from this flu at 55 as of this morning. This is behind Mexico and the USA. Unfortunately, this is a third world country and the government is scrambling and behind the ball and people are hording tamiflu and there is only one lab to test for the flu and it takes 15 days which is too long to get a good result. If you need tamiflu you need it quicker than the 15 days it takes to confirm. Ahhh, Argentina, I love you, I just hope you don't kill me.
Current Location: Buenos Aires, Argentina
Current Mood: ![[mood icon]](http://stat.livejournal.com/img/mood/niaha/kitty/ankthinkp.gif) contemplative
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