Imablog Perspectives of a Canadian in the Old/Deep/New/Geographic South: This is where I ramble on about nothing in particular and post a few nice pictures.

Happy Canada Day!

Happy 137th Canada day!

Saturn's rings up close

Tons of pictures from Cassini today. Most of them are closeups of the rings during the orbital insertion. Very cool if you're into that kind of thing. For the rest, it's just a bunch of boring pictures of grey stripes.

Images at JPL and NASA
Images from CICLOPS

I just want to get some sleep

Anybody who's married will tell you that there are times where their spouse wakes them up in the middle of the night. Maybe it's a jab to the side or a kick to the leg while they're sleeping, or nights they can't sleep so you shouldn't be able to either. Or they get up to pee and can't get back to sleep. Sometimes it's for good reason. Other times there's just no reason at all.

I wonder how many of them get woken up by a wet finger in the ear.

Yes, at 2 this morning, I woke up from my peaceful slumber to my wife sticking a finger in my ear. Not just any finger, but a wet one. And it wasn't just moist either. It was a wet, drippy slobbery (at least I hope it was just slobbery) finger being swirled around in my ear.

My wife woke me up with a wet willie this morning. And I can tell you, it is a rather shocking way to wake up.

Ugh, mail spam

Either spammers are getting better at constructing their messages to evade filters, are just spamming more or Earthlink's Spamblocker has been seriously sucking lately because the amount of spam making it through to my inbox has at least doubled over the past few days.

Normally I'd just see 7-10 messages a day in the junk mailbox when I check my mail in the morning and usually none throughout the day, but lately it's been more like 20-30 messages in the morning and a relatively steady stream of 2-3/hour throughout the rest of the day.

That said, Spamblocker is still great. What gets through is probably about a tenth of what gets intercepted. And what does get through gets tagged by POPFile and sent to the trash by my Eudora filters so I never have to dirty my eyeballs looking at it.

So hah! Take that spammers!

MathML test

Just checking to see if MathML is usable inside this weblog with my browsers at all.

${\left[a+b\right]}^{260}+{\left\{a+b\right\}}_i$

a + b 2

x 2 + 4 ⁢ x + 4 = 0

x = - b ± b 2 - 4 ⁢ a ⁢ c 2 ⁢ a

$\begin{pmatrix}0 & 1 & 0\\ 0 & 0 & 1\\ 1 & 0 & 0\end{pmatrix}$

$17+29i\in \mathbb{C}$

Rats, well that didn't work too well, did it.

Not quite sure I understand what's going on here. According to the sample pages it should mostly work with Firefox, Mozilla and IE6. Not sure why the examples above don't work. I must be doing something wrong...

Modelling a radionuclide generator in Excel

We've been teaching our first year (second year now) residents about nuclear medicine physics, and one of the topics we've covered is producing radionuclides for medical use. So I'm trying to whip up a spreadsheet that will model the activity of a typical Mo-Tc radionuclide generator to show off transient equilibrium and what happens when the generator is eluted.

Modelling the Mo/Tc activity in the generator is easy. What I'm finding a little more difficult is including the effects of generator elution where some of the Tc activity is removed from the generator. I'm thinking if I can reformulate the transient equilibrium equation as a recursive equation that looks something like A(t+dt) = f(A(t)) then I can get it to work. Spreadsheets are good at dealing with recursive equations. Should be simple.

So let's start with the Bateman equation (need to learn some MathML). For a 2 radionuclide (parent/daughter) setup, it looks like

A_d(t) = A_p(0)(λ_d/(λ_d-λ_p))(exp(-λ_pt)-exp(-λ_dt)) + A_d(0)exp(-λ_dt)

Now, it's a fairly simple exercise to show that when transient equilibrium is established, the recursive equation has the form

A_d(t+1) = A_d(t)exp(-λ_p)

But, when the generator is eluted, transient equilibrium no longer exists, and we need to go back to the Bateman equation to determine the daughter activity.

So, supposing that at time t=0, we have no initial daughter activity. Our equation looks like

A_d(0) = A_p(0)(λ_d/(λ_d-λ_p))

And at time t=1, we have

A_d(1) = A_p(0)(λ_d/(λ_d-λ_p))(exp(-λ_p)-exp(-λ_d))

At time t=2,

A_d(1) = A_p(0)(λ_d/(λ_d-λ_p))(exp(-2λ_p)-exp(-2λ_d))

Already we can see that the term containing the difference of exponentials

exp(-λ_p)-exp(-λ_d)

Tour de France Day 1

It's day 1 of the Tour de France. Starting with a short individual team time trial (6.1 km) in Liege Belgium. Looks to be a simple out and back course. Fastest cyclist at the moment is Pereiro at 7:01.39, givng him an average speed of 52.1 kph. They're really cruising. I can only manage speeds like that for short bursts.

Today's OLN word of the day is CYCLYSM.

Tour de France Day 2

It's a nasty rainy looking day on the first stage of the Tour. Causing a little bit of trouble with spills, but nothing that looked too bad. Look for a big finish by the sprinters today.

Today's OLN word of the day is LANCE.

Stick a skewer in me and call me done

There are days where I wonder how the heck I ended up here. Why am I in a place where a cool summer morning is the same as a blazing hot summer day back home? Where the mornings start off at 25°C, which would be a scorching day back home. And it only gets worse from there as the day goes on. This is only the beginning of the hot season too.

Dogsitting

This weeked we're dogsitting for a friend of ours. My wife says the dog, Molly, is an Australian shepherd or something like that. She has a black shaggy coat and looks shepherdish, although for some reason she lacks a tail. A dog without a tail is a very strange looking creature. Molly's a pretty sweet dog, although a little spoiled and bratty. A bit of a scaredy cat too, at least until she gets used to things. Inquisitive too. And oh boy, does she ever drool.

She's a high energy dog, and most definitely not an apartment dog. If we had a big yard or an acreage, she would be a cool dog to have. I thinks she'd really go for the agility test thing. She really likes to walk and was pulling me all over the place earlier. Next time we go walking I'm going to have to break out my rollerblades.

Tour de France Day 9

There's just no break from the rain for the riders early on in this year's tour. It's becoming the year of the crashes with riders spilling almost daily. Lots of exciting sprint finishes on the past few stages. All the big contenders are still in good position going into the first rest day of the race. Starting Tuesday, the tour gets into hillier territory, so look for the standings to start shifting.

Fedora Core 3 Test 1

I see that FC3 Test 1 ISO images are out and available for grabbing. It's probably better to use one of the mirrors to grab it.

I wonder how you go about upgrading an existing Fedora installation...

Oh wait, I just need to look here for updates.

Tour de France Day 13

An entertaining stage today with some of the first big climbs of the Tour. Even the cows were getting into the race. Most days you see spectators waving flags and running along with the riders, particularly on the climbs. Today some cows decided to run along with the peleton too. I'm sure their owner is going to be the talk of the town.

Tomorrow it's into the mountains. Two big climbs at the end will be sure to separate the men from the boys.

Naptime!

It's almost 2AM. Way past my bedtime, but I can't get to sleep. Had a nap earlier this evening when I knew I shouldn't have, so now I'm wide awake watching an old rerun of Northern Exposure. Ironically enough, it's the episode about the Northern Lights messing up everyone's dreams.

I gotta say, I think Northern Exposure was one of the best TV shows ever made. It was quirky, the characters were interesting and it was just plain fun to watch. Ed was one of my favourite characters on the show. Ed was cool, in a kind of geeky sort of way.

DHCP issues with FC2

I'm sure it's just me, but my FC2 box seems to be having issues holding onto IP addresses. Our DHCP server here issues IP addresses with a lease period of 1 week. So why is it that every time I have to reboot the Fedora box or the network connection drops on me I end up getting a new IP address?

Hmmm.

Haven't started digging into it yet. No time at the moment, so it'll just have to wait and I'll just have to deal with it for the time being.

Trying to lure me away?

I wonder if the number of recruiters and headhunters calling you has any relation to reputation. Lately all the calls I seem to be getting are from recruiting companies looking to fill positions and asking me if I'm interested.

Grok make fire. Grok cook.

Just about to head out to the beach and grill my face off. The wife decided to organize a picnic/barbeque and invited a bunch of her classmates along. She's completely incapable of planning any kind of event without turning it into a huge production, so I expect I'll have my hands full grilling stacks of hamburgers and hotdogs while she entertains. Her planning skills usually make for memorable events though.

My pulled pork pseudo-barbeque came out very nicely again, but I'm hoping most people will want bugers so I can take most of it home with me :). I've got about 3 dozen burgers and a Sam's Club sized package of hot dogs to cook. That and the 10 pounds of pulled pork ought to keep people happy.

I just hope we don't get rained out before everything gets started.

Dog shows

My wife likes to watch dog shows on Animal Planet. Sometimes they're interesting. But I've always wondered why they don't put the dogs through any kind of skill test...kind of like the talent contest in beauty pagents.

After all, these dogs are being judged to see how they compare to the breed standard, and most dogs are bred for a particular purpose or task. So how can a dog be judged best of breed if they don't test to see if the dog can do what it was bred for? Sure, a dog can look good, but what if it's dumb as a post? Some best of breed that would be.

Stargate: Atlantis

I liked it. I think it's going to be a cool spin-off with bad guys that make the Goa'uld look like playground bullies. The new digital Stargates in Atlantis are pretty spiffy looking. The only problem I had with it was that the new team had absolutely no trouble communicating with they aliens they found in a whole other galaxy millions of light years away. I'm still looking forward to the upcoming shows though. Hopefully the Stargate writers don't fall into the same trap that the Star Trek writers seem to keep falling into and recycling plots.

Tour de France Day 16

It's a hot toasty day after yesterday's climbs devastated the group. Today is a relatively flat stage, which I'm sure will be used as a welcome rest stage after yesterday's stage and in preparation for tomorrow's stage heading into the Alps. I don't expect too much of a change in the standings today unless something big happens. I expect Voekler may hang onto the yellow jersey for another day unless yesterday's effort left him too drained to stay close to Armstrong.

Today's OLN word of the day is BREAK AWAY.

Chillin' on the beach.

Yesterday's beach picnic turned out reasonably well. The rain stayed away long enough to get everything grilled, people to eat and spend some time playing on the beach. As expected, I spent most of the time walking back and forth between the two grills we had going to cook all the food. Didn't have quite as many people come by as we expected, so there was plenty of food left over. And just as I planned, setting out the pulled pork a little after most people filled up on burgers and hot dogs ("Oh wait, there's some pulled pork barbeque too!") meant that there was plenty of pulled pork left over for me :). Excellent...

Imagine a Beowulf cluster of these!

This would be a pretty sweet machine to get my hands on. 1024 Itanium 2 processors all acting as a single computer running off a single Linux image, rather than 1024 separate nodes like in regular clusters. Throw in 3TB RAM and 370TB of storage and you've got some serious computing at your fingertips. When it's operational, it alone will account for 1/6 of NCSA's computing power and doubles their existing storage space.

The SGI® Altix® system, to be named Cobalt, will consist of 1,024 Intel® Itanium® 2 processors running the Linux® operating system, 3 terabytes of globally accessible memory, and 370 terabytes of SGI® InfiniteStorage that will serve as the Center's shared file system, accessible by other high-performance computing resources within NCSA.

Found at Slashdot.

It's dead Jim

My wife's cellphone has finally given up the ghost. If you squeeze and twist it just right, you can get it to start up, but then it dies again. I figure all the times she's dropped it has knocked something loose inside the phone. So now I have to go find her another one. I was looking at the Motorola V400 because it's a pretty nice looking phone, but it has no IR port. She uses the IR to beam stuff between her PDA and phone, so now I'm trying to decide if I should just replace the Nokia 6360 with another one or go with the 3200. The 3200 does a little more than the 6360, but it has a smaller battery which might not go over too well with the wife.

This is what Nokia puts on their cell phone battery pages:

Replacing a Battery?
A new Nokia phone may cost you less than a battery, after rebates, with a new wireless service plan.

Let's eat!

Alton Brown says it pretty well in his latest rant/blog after seeing Supersize Me!.

We are fat and sick and dying because we have handed a basic, fundamental and intimate function of life over to corporations. We choose to value our nourishment so little that we entrust it to strangers. We hand our lives over to big companies and then drag them to court when the deal goes bad. This is insanity.

Is MacDonalds food bad for you? What do you think? Does that mean you shouldn't eat it? No, it just means you shouldn't live on it or anything else made by someone you wouldn't hug.

Anatomy of a Nokia 6360

So now that my wife has a new Nokia 3200, I thought I'd disassemble the old phone and see if I could make it work reliably again. I figure cell phones can't have that many parts inside, so it's probably just a matter of tightening or reseating any connections between boards.

So let's see what's in this thing.

This is the Nokia 6360, albeit a rather beat up one.

We begin our dissection by carefully removing the dorsal cover to expose the battery. The battery is a standard issue 3.6V 900mAh Li-ion battery that Nokia claims to deliver 5 hours talk and 12 hours standby time.

After removing the battery, we see there are 4 Torx screws that need to be removed to take the back cover off. A suitably sized hex wrench can be used to remove the screws if a Torx screwdriver is unavailable.

There is a compartment at the bottom which looks like it might be used to contain something, but it's empty.

When the screws are removed the front cover pops off exposing the button pad and LCD screen. I'm guessing the small rubber circle at the base of the phone is the microphone. The speaker is actually embedded in the top cover and connects to the main board via two circular contact pads above the LCD screen.

Looking down the top of the phone we see the power switch and the two LEDs used for infrared beaming.

There are two additional screws above the LCD screen that need to be removed in order to extract the main board. Two clips at the base of the phone also serve to restrain the main board. Carefully press these out and the bottom section of the main board can be slid out. Don't push too hard or you'll break the clips.

The top portion of the main board contains what appears to be the radio components of the cell phone. I would guess that the perforated metal cover serves as an RF shield for the radio bits.

There are three prominent ICs on the bottom portion of the main board, along with the power and main connector, battery terminals and several contact pads. The two rectangular contact pads closest to the battery terminals are used for the vibrating alarm. Two contact pads on the opposite side of the main board connect to a small square object embedded in the back plate with the vibrating alarm. I have no idea what this object does.

There is a peculiar chunk of plastic type material at the top of the phone in the back section. There is a silvery paint on it and it contacts the main board in two places: just below the IR LEDs and and at the side of the main board opposite the little nubby thing. This would appear to be the actual antenna for the phone. Quite a bit different that I thought it would look like.

Since there was nothing to reconnect or reseat (everything connects via contact pads), the only thing to do was just clean off the contact pads, reassemble the phone and make sure all the screws were tight so that everything makes good contact. After doing that, the phone seems to operate reliably once again.

We are squishy inside

There are times when my wife tells me far more anatomy than I really want to know. Like how the lungs of her cadaver are all squishy, and the sounds it makes when she squeezes them. She says it's cool. Me, all I need to know is that there are hard bits protecting the soft squishy bits and that keep the squishy bits from collapsing into a pile of goo.

Headed to the AAPM meeting

This weekend I'm headed to Pittsburgh for a week for the Annual Meeting and Summer School. This will be my first AAPM meeting and I'm looking forward to catching up with some friends there.

I've never been to Pittsburgh so it should be interesting, although I don't know that I'll have much time to check out much of the place. Probably just the area within walking distance of my hotel and the convention center. Looking forward to checking out Carnegie Mellon too, where the Summer School is located.

Gotta make sure I remember to bring my camera.

Hopefully I'll be able to find a TV station there that carries Tour de France coverage, otherwise I'm going to miss the last week of the race.

Live from Pittsburgh!

One cancelled flight and a delayed flight later I finally made it to Pittsburgh 7 hours after I left for the airport in Charleston. It was only supposed to be a two hour trip.

So far I like what I see of Pittsburgh, although I haven't seen much except for the road between the airport and downtown. Pittsburgh has a very nice downtown area that is easily walkable. It's a very hilly area, which is a nice change and sharp contrast to the flatness of Charleston, where the only hills you're going to encounter are overpasses and bridges. Long riverfront areas make for a nice place to walk in the evenings. The convention center where the AAPM meeting is only a short 15 minute walk from my hotel, and there looks to be a lot of shops and interesting little restaurants very near by. And even better is that the hotel I'm in, The Renaissance Pittsburgh (besides being very posh and stylish), offers free Net access! It's slow, but adequate. Faster Net access can be had for a price, but their free service is enough for my needs. The monitor on this ancient relic of a laptop I'm using (a P120 Dell Latitude XPi) is choosing this week of all weeks to flake out on me though.

Got here just before a baseball game started, so there were throngs and throngs of people around headed to the ball park. It's quite the sight to look across the river and see a stadium full of people, and then to hear them roar when something good happens.

Tomorrow is the first day of the meeting, and I expect to be busy with committee and task group meetings most of the day.

AAPM Day 2

It's been a pretty good meeting so far. Lots of good topics at the Continuing Ed and Scientific sessions today. Managed to meet up with a few friends too and arrange some times to get together and catch up.

Started off today with a CE session on PET physics and instrumentation. Basically a review of the innards of PET detectors and scanners. Nothing new, but the speaker did cover some more recent developments in PET/CT scanners. A good intro for physicists needing to learn about PET.

Second session of the day was one on Fluoroscopy and image perception given by Phil Rauch, one of my mentors at Henry Ford Hospital. An excellent talk on the clinical goals of fluoro imaging and touching on some aspects of image perception. I think the part of his talk on picking out signal from a noisy background really made an impact on the audience. I'll have to get a copy of his presentation and use it for teaching our residents.

The AAPM President's symposium was on the future of diagnostic imaging and radiation therapy. A very timely topic with some excellent speakers. More and more there is this new field emerging as a union of therapy and imaging. It's not quite diagnostic imaging, but it's not quite radiation therapy. You have things like image guided therapy and imaging for staging disease and monitoring therapy. You really see it in the number of radiation therapy centers opening up imaging departments. The use of PET/CT in oncology is a major driving force in bringing PET into hospitals, even though the technology has been around for 20 years now. I think diagnostic radiology and radiation therapy departments will start getting closer again in the coming years. Ironic considering that many radiation therapy departments emerged from radiology departments 30 or 40 years ago.

The afternoon was taken up by a science session and symposium on CT noise metrics. Interesting talks on various ways of measuring noise in CT imaging. Even though I haven't made much in the way of meaningful contributions to the TG yet, I'm learning a lot more about CT just by being part of the task group.

The evening started off with the AAPM Awards ceremony and reception. Congrats to my friend Stephen Steciw for being part of the group that won the Farrington Daniels award for best dosimetry paper in Medical Physics. Then after the reception it was a bit of a HFH physics resident reunion dinner with some former fellow residents and physicists. It was a good time and really nice getting caught up.

Looking forward to another good day tomorrow.

Coming for MT 3.1

Looks like there are a lot of new things coming for MT 3.1 that we can look forward to in about a month or so. Things like scheduled posting and the ability to publish dynamically, which should help ease the pain of rebuilding. Also a plug-in pack with the winners from the plugin contest.

Can't wait!

AAPM Day 4

The last full day of AAPM, and I'm ready to head back. Unfortunately I have to stay for the Summer School too. My brain's pretty full now but I'm stuck till Sunday. Guess I'll have to make some more room in there somewhere.

Last night's AAPM Night Out at the Carnegie Science Center was a lot of fun. Such a cool place and so many fun things to do! I think it was a good time for everyone who went. I certainly had a good time playing with all the displays, like the lasers and the sound tube or the paper airplane wind tunnel. And the miniature railroad was pretty sweet too. A huge model train set with a whole bunch of tiny detailed movements in the scenery. The Robotics display was pretty cool too. Lots of people tried their hand at making the robot arm shoot free throws. CSC is definitely a fun place to go play.

Lacking any other AAPM sanctioned events, I went out with a couple of friends to catch the Pittsburgh Pirates play the Atlanta Braves. It was the first major league baseball game I had ever been to. An interesting event. Lots of people wandering around, watching the game, eating and drinking beer, and socializing. Pittsburgh lost 1-0 despite managing to get 11 hits versus Atlanta's 5. Watching the pyroghy (or perogie as they spell it here) race was entertaining. At first I wasn't quite sure what the heck those weirdo half moon things were, but then I realized they were pyroghys. Strange thing to race I thought, but hey, the crowd seemed to enjoy it. It was a pretty close finish. I think they might have had to go to the photo for the winner.

You know you're a medical physics geek when you're looking at the Jumbotron and wondering what the MTF characteristics of it are.