I can (finally!) talk about one of the most interesting discoveries I made during my postdoc at Cambridge, in Walter Federle’s lab. (For a primer on sticky feet, check out my last post.) In our paper, published yesterday in PLoS ONE, we describe for the first time fluid secretions associated with arachnid adhesive pads, most surprisingly in spiders.
Why is this surprising? Fluid secretions have long been observed on the adhesive pads of insects, but we had several good reasons to believe that, despite their common arthropod ancestry, spiders were using a dry adhesive mechanism like the gecko.
- Spiders shouldn’t need a fluid. Both spiders and geckos have elaborately branched, “fibrillar” adhesives, which theoretically allow them to adhere solely by dry, intermolecular interactions. Beetles and flies have fluid-aided fibrillar adhesives, but their adhesive hairs are much simpler in structure. We wouldn’t expect them to be able to stick without a fluid (or at least not as well).
- Insects and spiders are both arthropods, but they’re about as distantly related as you can get and still be arthropods. There are a LOT of species more closely related to each group that don’t have adhesive pads at all, which is to say that they evolved their adhesive pads independently, and we can’t assume that what we know about one group applies to the other.
- Many previous researchers have studied spider adhesives and reported the absence of an adhesive fluid, and the absence of the secretory apparatus to produce such a fluid. The consensus in the literature up till now was that spiders have a dry adhesive.
So that was my assumption when I arrived at Cambridge. After studying the dry adhesives of geckos for many years, I wanted to see how they compared with their arthropod counterparts, the spiders. My labmates in Cambridge studied insect adhesive pads in ants, stick insects, cockroaches and beetles, all of which secrete very complicated fluids – biphasic, viscous, rate-dependent, non-Newtonian emulsions with hydrophobic and hydrophilic components. If it were up to me, I wouldn’t touch that stuff with a ten-foot pole.
Science had other ideas. I wanted to see what a spider’s foot looked like as it was adhering, so I used a technique called interference reflection microscopy (IRM), which is a great method for visualizing interfaces. I had to corral a spider in a small box and convince it to cling, upside-down, to a microscope slide underneath the microscope stage. It wasn’t easy, but when I finally found a willing participant – a young Chilean Rose tarantula – I sat and watched for a while. At first, it was just as I expected. I could see thousands of minute hairs making close contact with the surface. But after a few minutes, the spider started slipping. (Glass isn’t the easiest surface to stick to, believe it or not.) The spider kept repositioning its feet, trying to maintain its grip. And that’s when I started to see streaks of fluid left behind where its feet had been.
Figure 1. (A) Tarantula (Grammostola rosea) setae. (B) Fluid trail left behind by a Grammostola tarsus. (C) Mite (Gromphadorholaelaps schaeferi) clinging upside down to a polystyrene-coated glass coverslip, showing two adhesive pads in contact. Footprints are indicated by arrowheads. A trail of fluid is also visible, lower left. (D) Jumping spider (Salticus scenicus) fluid trail from one tarsus. (E) Solifugid (Gluvia dorsalis) tarsus, arolium situated distally, at base of claws. (F) Fluid footprint left by one Gluvia arolium.
Once I’d found fluid in one species, I started to look at other spiders, and other arachnids. I was particularly interested in the spider relatives called solifugids, which have smooth adhesive pads. Previous researchers had reported that they had not found a secretion, which would have made it the only known smooth pad to adhere by a dry mechanism. I got in contact with Sérgio Henriques, who was able to supply us with solifugid specimens from Portugal. They too had fluid secretions, as well as various mites (with smooth and fibrillar pads). It appeared to be a general trend. I asked Jan-Henning Dirks to apply his IRM expertise to my arachnid footprints, and we determined that much like the footprints left behind by insect feet, they were hydrophobic, with very low contact angles, and remained liquid indefinitely. (The hydrophilic component of insect secretions is difficult to catch on camera, as it is extremely volatile and evaporates instantly on exposure to air. We suspect that arachnid secretions are biphasic like the insects’, and thanks to Walter we have evidence of such a secretion from a single mite, but obviously this needs to be investigated further.)
Why hadn’t anyone noticed these secretions before? We speculate that researchers did not expect to see them, having heard others (including myself) describe them as dry adhesives. The fluid trails are very small, and their refractive index is close to that of glass, making them difficult to see with standard light microscopy techniques. Finally, the fluids aren’t continuously secreted. This suggests that spider adhesive pads, and perhaps those of the other arachnids, function adequately without the secretion. (Maybe they even work better without it!) Further study is clearly needed to test such a hypothesis.
In the end, though, it turned out we weren’t the first people to see these secretions. After submitting our manuscript for publication, we discovered a letter from John Blackwall, Esq., F.L.S, addressed to the Secretary of the Linnean Society of London in 1833, describing some observations he’d made of spiders clinging to glass:
“… The next point to be determined, therefore, was whether spiders … when moving in a vertical direction on clean glass, leave any visible track behind them.
“Careful and repeated examinations, made with lenses of moderately high magnifying powers, in a strong light, and at a favourable angle, speedily convinced me that my conjecture was well founded, as I never failed to discover unequivocal evidence of its truth; though in the case of the spiders considerable difficulties presented themselves, in consequence of the exceedingly minute quantity of adhesive matter emitted by the brushes of those animals. On submitting this secretion to the direct rays of the sun, in the month of July, and to brisk currents of air, whose drying power was great, I ascertained that it did not suffer any perceptible diminution by evaporation under those circumstances.”
At least we can say our findings are consistent.
Citation: Anne M. Peattie, Jan-Henning Dirks, Sérgio Henriques, Walter Federle (2011) Arachnids secrete a fluid over their adhesive pads. PLoS ONE 6: e20485. (doi: 10.1371/journal.pone.0020485)
Animals have evolved a variety of strategies for gripping, scaling and clinging to surfaces. Arguably the most powerful of these strategies is the adhesive pad. If an animal can walk upside-down on a smooth surface, there’s an excellent chance it has adhesive pads on its feet. These pads are unlike anything humans have engineered. No glue or suction cups or velcro or magnets are involved. They work sort of like tape, if tape were self-cleaning and could be attached and detached rapidly and repeatedly without any loss in performance. (So, not really like tape at all.) Many different animals have evolved adhesive pads specifically for locomotion, and these pads vary considerably in their structure and underlying mechanism.
The two basic adhesive pad structural forms we see in nature are smooth and fibrillar. Smooth and fibrillar pads can in turn be “wet” or “dry”, depending on whether the animal secretes a fluid over them.
Fibrillar pads resemble microscopic forests, or toothbrushes, and are sometimes referred to as “hairy” adhesives. Geckos, spiders, beetles and flies have fibrillar adhesives.
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| Ptyodactylus hasselquistii by Anne Peattie |
Gecko adhesive (Thecadactylus rapicauda) by Anne Peattie |
Smooth pads look more like balloons or rubber balls. They’re defined by their smooth, continuous surface. Animals with smooth pads include frogs, bats, grasshoppers, cockroaches, ants and stick insects.
How do they work? (The short answer)
Despite their differences, both types of pads can do one thing very well: adapt and conform to just about any kind of surface, down to the sub-micron scale. Regardless of their material properties, they behave like very soft, compliant structures. This compliance allows direct intermolecular bonding between the foot and the substrate. Individual hairs on fibrillar pads are composed of a stiff material, but each one can bend and adapt to meet either rough or smooth surfaces at a very local level. Smooth pads, it turns out, are actually fibrillar on the inside, but appear smooth because they are covered with an unbroken layer of soft material. Despite this extra layer of material, smooth pads are just as good at conforming to bumpy surfaces as fibrillar pads are (Bullock et al., 2008). Once this intimate contact is established, molecules making up the pad come in such close contact with molecules making up the substrate that they become attractive to each other and form intermolecular bonds, namely the ubiquitous and versatile van der Waals interactions.
Tape: a human-engineered adhesive
Tape, which also relies on intermolecular bonding for adhesion, is a layer of very soft material (the tacky side) bonded to a layer of stronger material (the non-sticky backing). When you apply tape to a wall, that soft material oozes onto the paint and in and around small bumps, forming bonds with the wall while maintaining its connection to the backing. Any loose debris (or thumbprints, or water) that gets in between the tape backing and the wall prevents the sticky layer from forming a bond with both of those surfaces, lowering the overall attachment force. When you peel tape away from a surface, it tends to leave behind a sticky residue. The softness of the sticky material makes it very weak internally. It tears apart when you peel it, some of it staying stuck to the substrate and some of it staying stuck to the backing (unless the substrate material is even weaker, in which case it carries some of the substrate away with it; either way it’s not going to work a second time). The strength of tape is dependent largely on its thickness. The thicker the tape, the bigger the bumps it can tolerate, and the stronger it will stick. Scotch tape has a thickness around 1/1000th of an inch (0.025 mm), electrical tape is about five times that (0.13 mm) and duct tape can be ten times as thick (0.25 mm) or more. Even the thickest tapes are not that thick, and tapes perform best when stuck to smooth surfaces. The strength of tape’s bond further relies on a preload force – that would be your thumb – pressing the tape into the surface, forcing the goo to flow and conform to the wall. The harder you press, the stronger the bond (to a point). For this reason, tape is known as a “pressure-sensitive adhesive” in the industry parlance.
How do they work? (The longer answer)
Animals with sticky pads on their feet can run around without worrying about their feet getting clogged with debris or tearing apart as they peel away. Some of these animals can attach and detach all of their 4, 6, 8 or more feet over 10 times per second. They don’t have the time (or energy) to press each foot into the surface and yank it off again. A tape-like mechanism is not an option during rapid locomotion. So how do sticky-footed animals do it?
One important property of sticky feet is their orientation-dependence. Each individual adhesive pad has an active and inactive state. Unlike tape, sticky feet don’t need to be pushed into the surface, but they do have to be dragged across the surface, ever so slightly, to begin sticking. When the pad is oriented correctly, that drag pulls the adhesive pad further into its active state, creating more contact and stronger adhesion. This dragging motion is imperceptible compared to the motion of the whole foot, and adhesive pads evolved such that the animal doesn’t have to change anything about its normal climbing gait to use them. In fact, most animals with adhesive pads can adhere to a vertical surface without any effort at all; the body weight of the animal alone “loads” the adhesive, activating it. To detach, the animal simply shifts its pads in the opposite direction – or lifts them straight up – again requiring negligible effort beyond the normal movement inherent to a stride. In this sense, sticky feet resemble claws much more closely than tape. Claws only function while loaded in a particular direction, and reversing that load causes them to unhook from their purchase. (This is not a coincidence; adhesive pads evolved in the presence of claws, and the two attachment modes had to work in parallel.) Tape, once engaged, resists detachment no matter which way you pull on it. In designing an adhesive meant for permanent or static detachment, orientation dependence would be a flaw. But for rapid, dynamic attachment, it’s a feature.
Sticky feet are self-cleaning, which is probably one of the coolest and least understood things about them. We can watch it happening before our eyes in the lab but the mechanism is still something of a mystery. Part of the answer is in the orientation dependence I described above. Between each step, adhesive pads revert to their non-active state. The gecko’s dry, fibrillar adhesive branches into minute tips so small (200 nm) that each one, on its own, hardly adheres at all. Only when the animal activates millions of these tips in concert, distributed across all of its toes, does it generate enough force to support its body weight. Between steps, any debris that was in contact with just a few dozen, or even a few thousand, of these tips will suddenly find that it’s in contact with far fewer as the adhesive hairs spring into their inactive configuration, leaving the debris suddenly unattached and easily brushed away as the animal initiates its next step (Hansen & Autumn, 2005). Smooth pads also change shape between steps, contracting and radically decreasing the available surface area of the pad, but perhaps more importantly, smooth pads are always “wet”. That is, animals with smooth pads secrete a fluid over them, which could help “wash” debris away. Many animals with fibrillar adhesive pads also secrete fluids over their feet, so this potential strategy is not limited to smooth pads (Clemente, et al., 2010).
It’s important to note that fluid secretions from adhesive pads do not act like glue. They don’t dry out and harden. They are viscous (like oil) but not inherently tacky, the way honey is. (If you want to get technical about it, they are non-Newtonian emulsions; Dirks et al., 2010) Secretions seem to help fill in gaps on uneven (rough) surfaces, improving attachment, but on smooth surfaces, less fluid is better (Drechsler & Federle, 2006). Researchers are still working out their exact contributions to attachment.
Finally, animals with adhesive pads can stick to a wide variety of different surfaces, from smooth, waxy plants to rough, dusty rocks, plus a lot of things they never encounter in nature, like silicon wafers and glass slides. In general, sticky feet adhere more strongly to smooth surfaces than to rough, and there is good reason for this. All of these animals have claws, which work fine as long as there are bumps and crags to hook onto. Adhesive pads represent an overall improvement in attachment capability over claws – some animals have even lost claws after evolving adhesive pads – but their exceptional performance on smooth surfaces suggests that adhesive pads are an adaptation for climbing smooth surfaces in particular.
References cited
Bullock JMR, Drechsler P, Federle W (2008) Comparison of smooth and hairy attachment pads in insects: friction, adhesion and mechanisms for direction-dependence. J Exp Biol 211:3333-3343 (doi: 10.1242/jeb.020941)
Clemente CJ, Bullock JMR, Beale A, Federle W (2010) Evidence for self-cleaning in fluid-based smooth and hairy adhesive systems of insects. J Exp Biol 213:635-642 (doi: 10.1242/jeb.038232)
Dirks J-H, Clemente CJ, Federle W (2010) Insect tricks: two-phasic foot pad secretion prevents slipping. J R Soc Interface 7:587-5593 (doi: 10.1098/rsif.2009.0308)
Drechsler P, Federle W (2006) Biomechanics of smooth adhesive pads in insects: influence of tarsal secretion on attachment performance. J Comp Physiol A 192:1213-1222 (doi: 10.1007/s00359-006-0150-5)
Hansen WR, Autumn K (2005) Evidence for self-cleaning in gecko setae. Proc Natl Acad Sci USA 102:385-389 (doi: 10.1073/pnas.0408304102)
Further reading
Peattie AM (2009) Functional demands of dynamic biological adhesion: an integrative approach. J Comp Physiol B 179:231-239 (doi: 10.1007/s00360-008-0310-8) [PDF]
A recent paper by Rind et al. in Journal of Experimental Biology, titled “Tarantulas cling to smooth vertical surfaces by secreting silk from their feet”, got a lot of press coverage when it came out, as well it should have – but for completely different reasons than it did. The authors present some beautiful morphological descriptions of the silk-secreting spigots on tarantula feet, the existence of which was originally described by Gorb et al. in their 2006 Nature paper, “Silk-like secretion from tarantula feet”. That paper was later questioned by another team of investigators who were unable to reproduce the results, so the Rind et al. paper is particularly valuable in that it puts an important debate to rest, while also providing insight into the evolutionary history of silk-spinning itself. As the authors note,
[T]arsal silk secretion would provide strong support for the hypothesis that spider spinnerets are derived from modified limbs (Shultz, 1987; Shear et al., 1989; Damen et al., 2002; Selden et al., 2008), and direct silk secretion from a setae on a limb without any complex storage organ may represent the ancestral condition, with silk production from abdominal spinnerets being the product of much later evolution. The ability of spiders to secrete silk from their feet would show that silk production is controlled by developmental modules able to be expressed in a variety of body parts (Selden et al., 2008).
Tarantulas and other mygalomorphs represent some of the most “basal” spider species – that is, they are thought to resemble ancient spiders more closely than other spiders living today. The discovery of silk-secreting organs in a group of more highly derived spiders would be interesting but not as informative on a historical level; it would suggest that tarsal silk is possible, and might have existed previously, or it might be new to that group. The fact that tarantulas have tarsal silk tells us something about how silk evolved in all spiders, which is pretty cool.
Here’s my issue with the paper: it’s called “Tarantulas cling to smooth vertical surfaces by secreting silk from their feet”. This has nothing to do with the evolution of spider silk. How about some bullet points?
- Tarantula feet are covered in adhesive hairs, much like those of geckos, which generate large adhesive forces. To say that tarantulas cling to smooth vertical surfaces by secreting silk from their feet is therefore leaving out a large piece, if not the vast majority, of the attachment pie. If you want to talk about adaptations for climbing, adhesive setae are where it’s at. They’ve arisen multiple times independently in several different groups of spiders besides tarantulas, not to mention in geckos, mites, beetles, flies, and a bunch of other insects.
- The authors provide no mechanical data to support their assertion that silk is involved in attachment. They note that it appears after the animal has slipped on a smooth vertical surface, and they note that the tarantula has a low safety factor. From these two observations they infer that the silk must aid in climbing. This is a hypothesis, not the demonstrated result of the paper. If I wanted to show that tarsal silk aided in climbing, I would try to disable the silk-producing setae and compare their climbing ability afterwards to their climbing ability with those setae intact. Considering that silk-producing setae are outnumbered by adhesive setae by about 50:1, I wouldn’t predict much of an effect, but that’s how I would test that hypothesis.
- The authors argue that silk could compensate for the low safety factor of large spiders, but if it does, it’s not doing a very good job. Tarantulas just aren’t that good at climbing, relative to other animals with fibrillar adhesives. This is a classic surface-area-to-volume scaling problem. Adhesive force scales with surface area, while body mass scales with volume. Bigger animals can’t increase their adhesive pad area enough to compensate for their added weight, so safety factor (potential sticking power divided by body weight) goes down as animal size goes up. (Aside: In my opinion, safety factors aren’t a useful way of thinking about evolution. We’re all living on the edge by certain measures, and “overbuilt” by others. Animals fall and die sometimes. More safety is pretty much always better.) Then, the authors themselves point out that not all tarantulas are large. If – again, as I see it, the main finding of the paper – tarsal silk is the ancestral condition, we would certainly expect to find it in all tarantulas (and while we’re looking, let’s check out some spiders from the even more basal Mesothelae), including the small ones, contradicting the safety factor argument.
Finally, since we’re talking about spiders “shooting” silk out of their feet (which, sorry, doesn’t happen – it’s secreted, it’s exuded, it’s not ejected or projected or anything like that, and they certainly aren’t shooting webs out of their feet but who reads the Daily Mail anyway?), let’s talk about Spider-Man. Spider-Man’s silk is much like that produced by orb-weavers. It’s the sticky, prey-trapping silk that most people think of when they think of spider silk, from the Charlotte’s-Web-type spider most people think of when they think of spiders (unless they’re thinking of a tarantula). Tarantulas don’t spin sticky, viscous webs to capture prey. They find prey and grab that prey with their pedipalps, which, much like their legs, are covered in adhesive hairs. Tarantulas use their silk to build nests. They are not swinging around on it like Tarzan. I can only speculate, but I’d say that when the creators of Spider-Man gave him his silk-shooting wrists, it was an understandable compromise resulting from the rocky union between the posterior spinnerets of an orb-weaver and the mammalian tetrapod body plan (that’s two arms and two legs for you non-biologists). Mapping the former onto the latter, Spider-Man’s silk should technically be shooting out of his, well, butt. I don’t blame the artist for taking some license and moving the silk-producing organs to a less repellant location. However, that choice was entirely coincidental with the evolutionary history of spider silk spinning and has no evidential weight in evaluating whether tarantulas use their silk to climb vertical surfaces, poorly.
Thoughts?
ETA In the interest of full disclosure I am the author of a paper in press about spider feet and their attachment mechanism. Watch this space.
Several years ago, while at a conference, I ran into an emeritus professor from my department at the poster session. He had recently met his first grandchild, and all he wanted to talk about was the joy of parenting. He said, “If you’re a biologist, you really have to have a kid. You just learn so much about biology.”
That comment stuck with me, and once I had my daughter, it resonated. Development, genetics, behavior, immunology, endocrinology, psychology, motor control … digestion. (Lots of digestion.) I imagine her neurons stretching and linking, making connections and refining them daily. She can say “dog”! But now every animal is a dog (“woof woof!”). She knows “baby”, but everyone is “baby” – at least, until she learns a few more words. She can tell the difference between animate and inanimate objects, animals and humans. It blows my mind that there was a time when I didn’t know these things. Suddenly I wish I’d taken a philosophy course. Meanwhile, my parenting strategies are based on my understanding of evolution. I constantly ask myself how our current environment compares with those we evolved from, and how our ancient physiology and anatomy react to things like anti-microbial soap, diapers, and processed foods.
Other professors (also parents) told me never to have kids. Those remarks were made in the heat of high-stress moments and I didn’t take them seriously. Still, they were inappropriate and I hope they were never repeated to any other students. Every year I know, or know of, more moms who are successfully pursuing tenure-track faculty jobs. I’m optimistic that attitudes are changing, that more women are seeing scientific careers as a realistic and rewarding possibility, and that for every woman who heads down that path, ten more young women are encouraged to follow in their footsteps.
Thank you to David Wescott for putting #scimom in motion. I hope to see #scidad next!
edited to say: For more #scimom posts see David Wescott’s list on his blog. I’ve linked to a few of the early ones below.
The Mother Geek blogs about her parenting “thing”
Nutgraf with kind of a fan letter to science
Motherhood has made Micro Dr. O a slob
Susan Wells on why she and her kids love science
Emily Finke still drinks water out of the hose.
The Wandering Scientist talks about motherhood, science, and all that.
Sheril Kirshenbaum tells parents to focus on critical thinking if they want kids to get interested in science.
ETA: Not official #scimom posts but recent and relevant
Elaine Westwick on increasing diversity in science blogging
A Hypothesis Is A Wish Your Brain Makes by Catherine Connors at Her Bad Mother.
Nicole and Maggie explain Why I’m not a guilt-stricken mother and why I have it all and why the patriarchy sucks
I’ve been without an academic affiliation for close to a year now, an experience that’s given me a new appreciation for open acess journals. I still receive tables of contents for Nature and Science via e-mail, but I’ve given up reading them since I can’t get past the abstract page of the articles. For now, I learn about scientific breakthroughs much the same way as the general public does: from online newspapers and magazines, blogs and Twitter.
Yet I am still writing papers and submitting them for publication – so with my new perspective I am re-considering where I send those papers. The old model, in an ideal case, went something like: (1) Choose the journal with the highest impact factor, (2) Get lucky, pull strings, whatever it takes – I don’t actually know – and get your paper accepted by your first choice journal, (3) The mainstream media picks up your story and spreads a distorted, “sexy” version of the findings. Would I like Science or Nature to publish my best work? I won’t lie. Yes, it would be nice to get that kind of exposure. Will I be devastated if they don’t? No. Should publication in these journals be a prerequisite to finding a tenure-track job? Absolutely not. Is there a better way of defining the impact of your research? Definitely. Start with the Alt-Metrics Manifesto if you don’t believe me.
Here’s what I notice about papers written for open access journals: They are so very readable. The authors (and editors) consider their expanded audience. Look at any paper in a PLoS journal and you will see: What they did, how they did it, and why, all clearly stated at the top of the paper. The typical Science or Nature paper is dense with jargon and light on explanation, because the authors assume readers will be members of the field and that everyone else will read the press release. The situation has nominally improved with the introduction of (optional) supplementary electronic material, but overall the format provides lots of incentive for overstating conclusions and under-reporting evidence.
While I wait for an open access publishing nirvana, I take heart in the fact that peer review is no longer limited to two or three researchers chosen by an editor who may or may not know anything about the science at hand. The recent arsenic-eating-bacteria story was a great reminder that, more and more, peer review is happening immediately and publicly. No longer do we have to wait a year for a new paper, or for an editor-approved letter of rebuttal. Even more exciting in this case, the mainstream media picked up on the backlash and reported it. In this paradigm, it doesn’t matter so much where I publish a paper, just that I get it out there. The quality will be reflected in the post-publication reactions, rather than pre-determined by the anonymous few.
I have a lot to be thankful for this Thanksgiving: my daughter was born a year ago today. I put this video together for her.
First Year of Maeve from Anne Peattie on Vimeo.
I discovered, via fortunate coincidence, that this Victorian on the corner of 7th and Channing – which I walk by and admire every day – is an official Berkeley landmark. As is this former factory, which was across the street from our previous Berkeley residence. I admit, I sometimes get the impression that there is a group of radical Berkeley Landmarkists going around protecting buildings of questionable value. A cruise around the Berkeley Architectural Heritage Association website reminded me that, in this forward-thinking city, it’s easy to forget everything that came before.
Two books I can highly recommend, on that theme:
Berkeley 1900: Daily Life at the Turn of the Century, by Richard Schwartz
I am always fascinated by historic images of places familiar to me in the here and now. This book has ‘em, and much more.
On Her Own Terms: Annie Montague Alexander and the Rise of Science in the American West, by Barbara R. Stein
The truly amazing story of one woman with a passion for biology who, through a combination of strong will and ample financial resources, muscled her way into the boys’ club and left a lasting legacy.
This week, Oakland elected Jean Quan mayor, the first woman to hold the job. She will also be the nation’s first female Asian-American mayor. But the real story is how she was elected. November 2010 marked the introduction of ranked choice voting (RCV) to several Bay Area cities’ ballots. San Francisco residents have been using RCV since 2004, but for Berkeley, Oakland and San Leandro, this was the first time residents – and candidates – got a taste of the new system.
Candidate Don Perata, former President Pro Tem of the California State Senate and current lobbyist for the CCPOA, a powerful state prison guards’ union, apparently ran his campaign as he had with previous campaigns, telling supporters simply to vote for him. Jean Quan and fellow candidate Rebecca Kaplan did their homework, formed an alliance, and instructed supporters to rank them first and second. Their campaign slogan? Vote Anyone But Don.
Although Perata won the majority of the first place votes, he lost in the instant runoff when the vast majority of the second and third-place votes went to Quan.
From SFGate:
Perata never told supporters whom they should list second and third. As he pulled ahead on the strength of first-place votes on election night, he was asked by a KTVU-TV reporter what he thought would happen next.
“It’s a good question,” he said. “I don’t understand how ranked-choice voting works.”
It might be too late for Don, but future candidates would do well to read up on it.
Earlier today, I read a very interesting NY Times article about the vast sums of money spent by the USDA, on campaigns benefitting companies like Domino’s and Taco Bell, to promote ever greater cheese consumption – in direct contradiction with our federal dietary guidelines and the food pyramid, which are established by… the USDA. Between discovering the disgusting amount of saturated fat in a Taco Bell steak quesadilla, and not wanting to let Michelle Obama down in her fight against obesity, I started to think I might have to give up cheese, in solidarity. (Oh, and government agencies, huh? Think they could be a little more efficient?)
Thankfully, David Lebovitz’s take on making authentic swiss fondue was the perfect antidote to impending cheese-phobia. Although I may have caught a bad case of food envy.
I spent way too much time yesterday (including my extra daylight savings hour) trying to figure out how to speed up video in QuickTime. Hopefully somebody out there can learn from my experience.
How to speed up/slow down video in QuickTime:
1. Open original movie in QT.
Optional: Copy segment to be altered into a new player (I do this to avoid overwriting the original file)
2. Select all (command A) and copy (command C)
3. Trim the movie to desired *time* length – that is, if you have a 2 minute original file and you want to speed it up 10x, use the handles to select an arbitrary 12 second segment somewhere in the window and click “Trim to selection”. Now you have a 12 second video clip in the player.
4. Click on “Add to Selection and Scale” under the Edit menu to paste the scaled segment into the player. You should be able to play the clip now and see that it’s all there and sped up (or slowed down) appropriately.
5. Open Movie Properties and delete Video Track 1 and Sound Track 1. This is the arbitrary (12 second) bit you chose and then copied over in the previous steps, and it can come back to haunt you if you try to import the movie elsewhere (e.g. into iMovie)
6. “Save as…”
Warning: Theoretically the audio should scale with the video. I found that this didn’t always happen, and I’d lose the audio partway through the clip. To fix that issue, I opened up Movie Properties before scaling and extracted the original sound (Sound Track 1) to another player by clicking on “Extract” in the Movie Properties window. Once I was satisfied that the video had scaled properly, I selected the entire sound clip, copied it, and going back to the video window, I performed one more “Add to Selection and Scale.” That eliminated surprises down the line when I imported the clips into iMovie.
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