Archive for July, 2012

Achilles surgery — progress

July 29, 2012

Friday: Three weeks since surgery. My second physical therapy session. I rode the bike over, and the therapist put it up on a trainer and suggested a few things about my riding style, including not flexing my ankle so much as I came through the pedal stroke. Ok, that’s worth a try. He has also given me several stretches and exercises. From the viewpoint of stress on the ankle, I think the hardest is to rise up onto both toes, then let down only on the wounded leg.

He agrees with my general approach: do as much as I can and try not to do too much.

There is enough discomfort that I decided not to bicycle in to work (15 miles). I did the prescribed stretches and exercises, though, and by Saturday, the ankle was sore enough that I took a day off. Worked around the house, no stretches and no exercises.

Sunday, and I feel considerably better. Elmar is here from Sweden; with Jacky, we went to the Arastradero preserve for a short hike (4.7 miles, 600 vertical feet). Nice to get out, very nice indeed. It has been far too long! And by the time we got back to the car, I was beginning to feel a bit of pain in the ankle, so it was probably about the right distance for today. Elmar went on to do a real hike (Monument peak); I only wish I could go along. Next time!


July 24, 2012

I have read with interest several books – and seen a movie or two – about autistic people and autism. As one who always thinks of the right thing to say a second – or an hour – or ten years – too late to say it, I think I recognize some of what’s happening. Introspectively, I conceptualize my case as grinding slowly but exceeding fine. In some ways, it seems that I think slowly, but it may be that I consider more input than those who are instantly ready with a response.

What I surmise may be happening with the autistic is that they accept all possible input – photographic memory seems to be common – and in my analysis, they are so busy processing input that they never have the CPU cycles to generate output. Hence the external appearance that they are out of touch or even stupid. Not so; they just haven’t learned how to erect filters, filters that separate the inputs that matter from those that don’t. When eventually they generate output, they are often discovered to be brilliant or creative or both.

I haven’t studied the literature, so this may be well-known. Conversely, there may be hard evidence that my view is nonsense. Take this as an observation from someone who is close enough to that world to perhaps have some dim insight into it.

Patrick Basham: regressive taxation on sugary drinks

July 24, 2012

In this op-ed published on Cato’s site, Patrick Basham writes:

A sugar tax also has undesirable social and economic consequences. This tax is economically regressive, as a disproportionate share of the tax is paid by low earners, who pay a higher proportion of their incomes in sales tax and also consume a disproportionate share of sugary snacks and drinks.

Patrick, please explain why a regressive tax is socially and economically undesirable? After all, a regressive tax is more likely to encourage a majority to vote against increased government intrusiveness.

Think about it.


How we hear

July 22, 2012

As part of publishing my book, I of course got to know the people at Wiley to a certain extent. They invited me to review a book proposal, in return for which I was offered a credit against anything Wiley published. I browsed around and decided to indulge myself with a copy of Principles of Human Anatomy (Tortora and Nielsen), a topic that has always interested me.

It’s about a thousand pages, lushly illustrated. I have been working through it for many weeks now, and learning a lot of interesting things. Prior to my Achilles surgery, of course, I went over the foot and leg part of the book, an exercise during which it became very apparent that a thousand pages is only enough for a cursory overview. Although the drawings are very well done, I also found that dissection videos [not for the squeamish!] on YouTube gave me a much better understanding of the three-dimensional arrangements of these things.

Most recently I have been reading about eyes and ears. Lots of really interesting things about eyes, but this post is about ears.

To my nasty, suspicious engineer’s mind, the cochlear ducts with the organ of Corti look a lot like a filter. My thought was that forward- and counter-propagating waves might create highly localized resonance peaks that could help account for our ability to discriminate fine pitch. So I did some research.

Simple filtering doesn’t quite tell the story, but a lot is known. There are three outer rows of hair cells, which are mostly enervated by motor neurons (!), and a single inner row of hair cells, which receives about 95% of the efferent (sensory) neurons. The outer hair cells appear to act as an active amplifier (Gold, as summarized by Bell), and probably as a filter.

The ear actually produces sound — I didn’t know that! — otoacoustic emissions. I was disappointed not to find a recording of such an emission on the web. At any rate, none of this is new to those in the business.

I did find some interesting videos that explained how all this works in more detail:

The first one is a good introduction to the process of hearing, and in particular to the arrangement of the scala vestibuli, the scala tympani and the scala media (between them, as you would expect). The organ of Corti is the amplifier, filter and detector. It exists in the scala media, atop the basilar membrane, which separates the scala tympani from the scala media. A tongue-like membrane in the scala media, the tectorial membrane, overlaps and touches the tops of the hair cells. The simple idea is that motion between the membranes causes the hair cells to flex, ultimately resulting in the generation of a neural impulse and the sensation of hearing.

Hair cells are equipped in four rows, three rows of outer hair cells and one row of inner hair cells. 95% of the sensory neurons go to the single row of inner hair cells: this is where signal detection occurs. The outer three rows receive efferent (motor) neurons, and act to filter and amplify pressure waves before unleashing them onto the inner row.

All this is really cool, except for one small detail. In the part of this video that shows how auditory sensation is generated, the animation zooms in on an outer hair cell. Well, no, I don’t think so. Not unless there’s a whole lot of the story they’re not telling us!

The second video covers some of the same ground, but has some excellent electron microscopy of actual hair cells, and even shows a hair cell in action. Definitely worth the watching.

In the discussion about hearing loss, however, this video also talks about  loss of hairs on the outer cells, not the inner ones. Now, we would expect that loss of outer cell hairs would result in less amplification, perhaps, and poorer pitch resolution, but those are surely secondary effects. The primary loss would surely be loss of hairs on the inner layer cells.

I checked out several other models and animations, as well as learned papers on the web, and they all of them are missing what seems to me to be another important point.

Above (in the usual drawing) the scala media is the scala vestibuli, separated from the scala media by the vestibular membrane, also known as Reissner’s membrane. I found only one explanation of its purpose, namely to assist in maintaining chemical and nutrient balance for the part that really matters.

No, no, no. This is like hanging a dog on the wall in act I and then wondering why it did not bark in the night. If there were no functionality associated with the scala vestibuli, it wouldn’t be there, and for sure it wouldn’t have a flexible membrane coupling it in with the organ of Corti.

There has to be something there, and I return, with modifications, to my conjecture from the beginning that the difference between the pressure wave from the two outer scalae is related to delay evaluation and helps with stereolocation of sound sources.

Further, the hairs on at least the outer cells are of different lengths, and could therefore plausibly be understood to respond to compression, rather than just horizontal displacement. That surely has to be part of the story, too.

Well, I am a complete amateur on all of this, and probably don’t even know what questions to ask, much less how to recognize a good answer. But I have also learned that the frontier of our knowledge is closer than we sometimes think, and a thoughtful question can sometimes be productive.

Achilles + 2 weeks: Saturday

July 21, 2012

Within the last two or three days, I have taken off the boot, abandoned the crutches, and driven the car. I am still using the boot, cinched tight, for my half-hour stints on the stationary bicycle, and although I am taking stairs two at a time (as usual), I am not running up. Being cautious and careful. I hope Dr Saxena would agree, but ultimately of course, it is my own responsbility. I see him Monday to have the stitches removed.

Today (Saturday) I walked to a nearby park, about three blocks away. Without boot or crutches, that may be enough for now, and besides, it’s a really hot day, not that much fun to be out.

And as always, a certain amount of careful inspection is rewarded by finding interesting things to photograph.

Achilles — the second Wednesday

July 18, 2012

For the first time this morning, I took a shower. Bathtub water is gray after the first round of soap and shampoo, and I don’t feel like I’m really getting clean; a shower is much better. Some improvising — sitting on the floor of the shower stall to wash the strong foot — but it feels good. The doctor wanted me to keep the wound dry until the stitches are removed, but it’s hard to believe that it’s still noticeably vulnerable to contamination. Let it be wet!

I have been working up my time on the bicycle, 5 minutes per day. Today I did 30 minutes, for the first time. The bike has toe clips; I released the strap and fit the toe of my boot into it, but it tends to twist my foot enough that the heel bangs into the chainstay, so I reverted to just using the flat side of the pedal.

How much exercise am I getting? Well, not very much, but at the end of my bicycle time, my clothes are soaking wet, water is running down my face and over my glasses, and there’s a liberal surround of water (not raindrops!) on the floor around the bike. Better than nothing.

What I learned is that I can do more if I cinch the boot up tight, to minimize the flexure of my ankle.

This afternoon I walked to the downtown library, about a mile in each direction, the longest walk yet. I’m embarrassingly slow, but it’s better than nothing.

Slowly, slowly…

Achilles surgery III, Thursday

July 12, 2012

The first day I tried the bike (Tuesday), I put in five minutes, enough to give it a try and see whether it was going to work out. Some pain, but not too bad. The ankle swelled, and there is probably some fresh bleeding under the skin. Ice makes a difference.

Yesterday, I put in ten minutes on the bike. I want to do as much as I can, but not more. I’m also getting more comfortable with the crutches, willing to go up and down steps and stairs now. My shoulders are not yet strong enough for any great distance, but certainly better than the first day or two (it also helps that I can offload a small amount of weight onto the booted foot).

Today, fifteen minutes on the bike, spinning as fast as I can, against not much resistance. About 80 rpm is the max I can sustain with my booted foot just sitting atop the pedal. If I could clip in, it would be higher than that. And I would work harder and flex the ankle and damage myself… oh well.

Then ice while I lunched on a peanut butter, onion and cheese sandwich.

And it’s a good opportunity for study of some technical topics that I have had on my list for a while, but never found time to learn about. All in all, I’m managing okay, but it will indeed be good to be able to get out and start doing real things again.

Later: I walked around the block. All the way around. First time, quite an achievement. How embarrassing, that walking around the block would represent a milestone!

Achilles surgery, Tuesday

July 10, 2012

Everything feels great, and if not for Dr Saxena’s words of caution, I would undoubtedly be out there overdoing it. As it is, I am trying to be cautious, as cautious as possible. The stitches come out in two weeks (believe it or not!), and I’m supposed to wear a boot until then, and not put weight on the foot.

At least I can take off the boot for much of the time, especially to wash! You never appreciate how good it feels to wash until you can’t! Here we see the doctor’s signature and an arrow, from the pre-op inspection.

This is the wound itself, a few strands from the cotton dressing still adhering. It is not oozing, and I will omit the cotton and the pad in future.

Though still wearing the boot to walk, I am putting my foot down with each crutch-assisted step, trying not to put too much weight on the foot. Still, it’s a great relief to my sore shoulders to have some of the weight offloaded. And of course, I have to work on yet one more gait. When I forget and put my full weight on the bad leg, there is enough pain to remind me.

Dr Saxena said it was okay to ride an exercycle as long as I didn’t flex the ankle. So I rigged Jacky’s bike in the trackstand — her bike has flat pedals — set up a stepladder nearby as a way to assist the clumsy climb on and off the bike, and got in a few minutes of exercise. Yet another new experience, not being able to clip into the pedal. Whenever I forget, my booted foot skids off the pedal, and the freely rotating pedal bangs me in the back of the leg.

Only about five minutes today; I could feel some pain in the wound, and I really don’t want a setback. I’ll do more later, maybe today, or at least on subsequent days.

Achilles surgery

July 8, 2012

I damaged my Achilles tendons some years ago, and they have been limiting my activities since. For example, I can no longer cycle in the hills, only on the flatlands. And I need a rest day between bicycle commutes or after long hikes. The right leg causes most of the trouble, and finally it was time to do something about it.

Dr Saxena at Palo Alto medical foundation is a respected sports medicine specialist in this area. He says it’s a tight paratenon, the lining around the tendon, causing overuse pain something like a carpal tunnel, and by slitting the paratenon, the pressure can be relieved and the pain disappears. I think I will be off the trails for 4-6 weeks.

I checked into the PAMF surgecenter Friday afternoon. The waiting room has a good-sized aquarium with colorful tropical fish. I went over to have a look, and noticed tiny stalks from the rocks and gravel at the bottom. On closer inspection, I saw that they were animals, sea lillies, I think (crinoids). I bet nine people out of eight don’t notice them!

Friendly and helpful people, and I like their processes to make sure everything goes all right. For example, I was asked several times for my name, date of birth, and why I was there. Dr Saxena came in and marked the right ankle while I was awake and paying attention. I suppose it gets really awkward if they do a heart transplant on someone who came in for hangnail repair.

They have curtained-off areas for the prep work, changing clothes, final consultation, paperwork and such. As they wheeled me down the corridor on a gurney to the operating room, I was irresistably reminded of Calvin: “Wheee!”

Next thing I knew, I was talking with an orderly who offered me water (they don’t let you eat or drink, not even water, after midnight of the previous day). Good idea; I drank three glasses. Jacky was there to give me a ride home. I am wearing a boot that immobilizes the ankle. It has a rigid sole and comes almost up to the knee. They want me to leave it on until the post-op consultation Monday morning.

I have never used crutches before, and I’m clumsy with them. I suppose by about the time I begin to develop some level of proficiency, I won’t need them any more.

There are a couple of steps up to get into the house, so it’s an opportunity to figure out how to deal with steps. One at a time, that’s how. The habits of a lifetime make it hard to resist going for the next one in an alternating pattern: I find I have to stop, think about it, and plan the ascent, to make sure I do it properly. Possibly even more risky going down, where the same temptation is even stronger.

Obvious in retrospect, but somewhat unexpected: when my hands are occupied with crutches, I can’t carry anything. Jacky is very good about helping with things, and I strapped on my cycling belt pack, which allows me to more or carry around at least some of the things I need.

They want me to put an ice bag at the back of the knee from time to time. This is as close to the wound as I can get, with the boot on, and I guess it helps cool the blood a little bit, to help reduce swelling. I’m not convinced it really makes much difference, but I do it anyway.

I made it safely to the second floor at bedtime. Jacky put a fat pillow at the foot of the bed, and I elevated the booted foot onto the pillow for the night. I omitted all of the pain pills. Big mistake? No, not really. A little worse than the usual 20-mile hiking aftermath, but not all that bad. Not the best night’s sleep I ever had, but okay.

Saturday morning, and I made it down the stairs without falling. I can tell that my shoulders will be sore from the extra load, but it will be yet another day or so for the full effect to show up. Spent the day around the house, mostly, although I tried going for a walk in the afternoon. It was about half a block out, half a block back, enough.

By evening, I was ready to try some exercises, to see if I can keep the bad leg from losing too much strength and flexibility. I’m wiggling my toes in the boot, and waving the leg around in all directions, flexing the knee, and pretty much doing everything I can think of that does not require motion at the ankle joint. Better than nothing… I hope.

Saturday night was still awkward wearing the boot in bed, but there is very little pain at this point. That’s encouraging.

Sunday I tried a tub bath, foot up on a low stool that we put into the bathtub. Clumsy, also something I hope I won’t have to get used to. Then I adjusted the crutches for a better fit. We went out by car for breakfast, and they do seem to be an improvement.

Sierra Azul

July 4, 2012

First, let me post a couple more pictures of my little friend from the backyard table. I have no idea what it is, but it sure is cute!

The fourth of July gave me one more excuse to go on a long hike before being out of action from surgery. Well, a moderately long hike. Only 13 miles, but 3800 vertical feet, and on a hot day in the south bay, it was long enough.

I parked at Lexington dam reservoir and hiked uphill in the Sierra Azul open space preserve. Took a trail that provides access to a string of electrical transmission towers; the high point is at 3000′, under one of the towers. Hot, dry, steep. Heavily overgrown with poison oak, but the trails are fire roads, so it’s easy to avoid. Lots of trees, scrub oak and buckeye, a little madrone and here and there a laurel. Because the trails are fire roads, there’s not as much shade as I would have liked. A few mountain bikes, a few hikers.

Across the valley we see the characteristic square block at the top of Mt Umunhum. It has to do with some kind of radar installation, now disused because of the end of the cold war. You see this square building against the sky from many miles away, specifically from the top of Page Mill road, looking down the San Andreas rift zone. The epicenter of the 1989 Loma Prieta earthquake was right near here.

Looking to the east, we see Mt Hamilton. This is the first time I have ever seen the Lick observatory below the skyline! The dome above the skyline is the 120 inch reflector.

I mentioned that the top of the hike was at the base of an electrical tower. While I munched calories and soaked up a bit of water, I searched for small animals.

I find empty cicada shells once in a while, but rarely see the animals themselves. This one had a strategy of playing dead, but after I flashed it a few times, it tried to crawl away and hide under a leaf.

This is the dead leaf of a fern. Quite common, but small enough that they’re easy to ignore.

Took an alternate trail down, alleged to go to or past Priest rock. I didn’t see any special rock formations.

Home before mid-afternoon to the block party, where I wandered over, shook hands with Clarence, the archetypal organizer (and I learned he had been a navigator in the RAF during the second world war), soaked up a few more calories, and mellowed out.

Spiders and snakeflies and harvestmen, oh dear!

July 1, 2012

Some catching up to do… when last I updated the blog, we had a collection of spiderlings. While the ladder was out, I took the opportunity to photograph an adult or two.

The photo below shows a spider that has just molted its skin! The old skin, there in front, and the new surface, light and shiny. That’s pretty cool.

A few days later, I was sitting in the back yard soaking up a beer, when a little guy came along and perched on my pants leg. The weave of the cloth (below) gives you an idea how big he isn’t!

And this little fellow ran back and forth on the rim of the table for quite a while.

<time passes> I hiked Purisima Redwoods open space preserve with Albert, and the next day, Big Basin Redwoods state park. Nice hikes, but I have no photos to post.

<more time passes> 1 July 2012

Today I left the car at the Wunderlich parking lot, hiked to Skyline, thence to Huddart park and back. As 22 mile hikes go, this one is pretty easy: one climb to Skyline, then along the ridge on a trail that is certainly not flat, but doesn’t gain or lose all that much extra elevation.

When I crossed Kings Mountain road, I stopped for a shot of the cyclists going down. They move right along.

I asked Albert if he knew why trees grow in spirals (he didn’t). When I asked the question, we were looking at an example of a right-hand screw; we speculated that trees in the southern hemisphere might twist the other way.

But here is possibly the most extreme spiral tree I have ever encountered, and it’s a left-hand twist. Most of the madrones around this area were also left-handed, although I saw some right-handed madrones further along. So maybe it’s just in the DNA.

On the way back downhill in Wunderlich park, I stopped to inspect a growth of thistles along the trail. At first I thought this was a tiny mantis, but when you think about it, it’s clearly not a mantis.

Upon research, I discover it’s a snakefly. I don’t think I have ever heard of snakeflies before, and I’m sure I haven’t seen any. Carnivorous.

And in the same area — if you weren’t paying attention, you might think this was a spider.

A harvestman, the other kind of daddy long-legs.

In this picture (above) we can see the little turret atop the head, with one eye on either side. Spiders are considerably more advanced than this.

Finally, a moth; I liked the dual yellow lines of the rolled-up proboscis.

This is the last hike for a while. Friday is for surgery on an Achilles tendon that has been giving me trouble for a number of years now. and I’ll be off the trails for a while.