Wikipedia:Reference desk/Archives/Science/2013 April 10

= April 10 =

Overlook, Portland, Oregon aka Swan Island
Can anybody help me find some information about the environment of Overlook, Portland, Oregon aka Swan Island prior to the industrialization of the 20th century and after it to the present day? Like flora and fauna. If not something about island ecosystems in the lower reaches of the Willamette River where it meets the Columbia. Again very specific, so I don't care anything about the ecosystem of Oregon in general only that specific region and if not only region similar to it on the islands of the lower reaches of the Willamette River where it meets the Columbia.--170.140.214.104 (talk) 16:20, 10 April 2013 (UTC)
 * Good luck. According to this source, in 1841 there was "a dense stand of oak trees" that were cut down to build the Star of Oregon.  Sean.hoyland  - talk 17:06, 10 April 2013 (UTC)
 * Searching with the term "Columbia River Estuary" might help a little. The Columbia River Estuary reaches to Bonneville on the Columbia and Willamette Falls on the Willamette, and as a topic of study tends to focus on the ecology (present and historic) of the rivers and their many islands, wetlands, floodplains. I didn't search very hard, but some possible leads: This page,, the slides of some presentation, says the Willamette River was much shallower, with broader wetlands along it, and that apparently the main channel went east of Swan Island instead of west as it does today (the east channel is now just an inlet/lagoon). One of the slides shows the Swan Island area's bathymetry in 1888 and 2001, another changes in "off channel habitat". It also mentions (as do many other sources) how dam building on both rivers has radically altered the river flow (flow seasonality and freshet magnitudes are greatly reduced now—that is, water flow and river levels used to change dramatically over the course of the year, but now they don't much). And this page, , which among other things describes historical conditions at various sites around the Willamette-Columbia confluence. As with other sources, it mentions the historic abundance of Sagittaria latifolia (wapato) on the river islands around what's now Portland. Another thing you could do is look for sources on other islands in the area that are more likely to the kind of info you want. Sauvie Island comes to mind as one for which there's likely to be a lot of info. We have a few excellent/featured pages about wetlands and small streams in the Portland area, like Columbia Slough, Johnson Creek (Willamette River), and Tryon Creek. While these pages might not answer your questions directly, they might help give a general sense of things, and their reference sections might have useful sources to check. Pfly (talk) 08:05, 11 April 2013 (UTC)
 * PS, you could also ask over at Wikipedia talk:WikiProject Oregon, where there are many friendly folk who know an amazing amount of stuff about Oregon and the Portland area. Pfly (talk) 05:56, 12 April 2013 (UTC)

Jewellery chain
Is there a page (maybe on the internet?) that shows/teaches how to make singapore chain, or box chain, and other designs, such as in Jewellery chain?Curb Chain (talk) 17:17, 10 April 2013 (UTC)

Are there materials that turn light into sound?
Clearly it is possible to hook up a solar cell to a loudspeaker. Shine light on the solar cell, the loudspeaker produces a tone.

Are there (artificial?) materials that do this spontaneousely? Materials that absorb light energy and re-radiate it acoustically? 81.11.175.240 (talk) 18:43, 10 April 2013 (UTC)


 * well this is not very general but it technically does meet the requirements: the laser light–generated using a commercial laser–ionizes a small area of water, which superheats, creating an explosion of steam that generates pulses of sound waves at about 220 decibels. Gzuckier (talk) 20:02, 10 April 2013 (UTC)
 * The problem which you would need to overcome is that light is electromagnetic while sound is kinetic. I also doubt hooking up a speaker to a solar cell would produce any audible tone, unless you also hooking up a tone generator. Or, maybe you could put a fan in front of the solar cell so that it is covered and exposed at an audible frequency. but then you're still not really getting "light into sound", you're generating a tone using sunlight as the "carrier wave". In a more convoluted way, we turn light into sound when we speak :) Vespine (talk) 00:49, 11 April 2013 (UTC)


 * A cat placed into a sunbeam will often purr. I know, I know, not right. But what I'm trying to get at here is that the transformation of electromagnetic energy into acoustic energy is probably only accomplished through some sort of complicated intermediary, such a large biological organism. For non-biological approaches, maybe something like the crack of a melting iceberg? Again, not exactly what you're asking for. --Mr.98 (talk) 01:14, 11 April 2013 (UTC)
 * I wonder if we could somehow involve Piezoelectricity? But that still requires voltage, not light, so not really any different to your speaker idea.... Vespine (talk) 06:01, 11 April 2013 (UTC)


 * The simplest way I can imagine to go from light to sound would be a material with albedo that changes depending on temperature. As it heats up, it gets more reflective. This causes it to absorb less light energy and cool down. Once it is cooler it is less reflective and able to warm up more again. Then you would have to find a way to make the interaction happen quickly enough that the thermal expansion/contraction creates an audible noise. The overall system would need to be underdamped to be able to sustain the oscillation, and I'm not sure if that is possible. 38.111.64.107 (talk) 13:52, 12 April 2013 (UTC)

Bed bug feeding frequency
Every few days I wake up with a bite and I'm wondering whether I might have bed bugs. At some point I also had a rash around my jaw which I attributed to acne. I don't know when that was though. I'm wondering how long bed bugs could go without nutrition? If I go home (I'm a student), how long should I stay away to ensure bed bugs have all died? I haven't noticed any other signs though. It might be something else biting me. Playful spider perhaps. --2.97.27.107 (talk) 21:12, 10 April 2013 (UTC)


 * Have a look at Bedbug. It explains they prefer to feed every 5-10 days, but in some circumstances can last much longer, up to a year. As far as I know, adaptation to rare feeding is common in blood suckers, with some ticks and fleas reliably going several months without a fresh blood meal. Also note that bedbugs can "share" their meals, by piercing the stomachs of their peers and stealing their meal. If that sounds bad, it's just the start. Bedbugs also procreate though traumatic insemination! SemanticMantis (talk) 22:28, 10 April 2013 (UTC)


 * Unfortunately, if your bed bugs were mature and have laid eggs, you can't just wait for the adults to die. The eggs could be in the seams of your clothing, or your luggage, or anywhere in your bedroom.  Have a look at the Bed bug article for other evidence to look out for before you take drastic measures.  I hope the cause is something less persistent.    D b f i r s   08:23, 11 April 2013 (UTC)


 * Although the question isn't strictly a request for medical advice, it would probably be in your best interest to consult a professional - in this case, the Orkin Man, or some equivalent. ←Baseball Bugs What's up, Doc? carrots→ 10:17, 11 April 2013 (UTC)

synthesising DNA
hi there, I was wondering if there was a technique which would produce the synthesis (rather than the sequencing) of a specific strand of DNA with a known sequence? Presumably using its base nucleotides? Does it work? Would it work?

could you set up a basic but high yield automated process to carry out protein synthesis from the amino acids, even for longer & more sophisticated proteins?

I'm already familiar with PCR, selecting existing sequences or alleiles for amplification or expression invitro - I'm interested in synthesising very long strands or sequences which may not be found in nature.

Thanks! Horatio Snickers (talk) 21:23, 10 April 2013 (UTC)
 * See Artificial gene synthesis. Dmcq (talk) 21:30, 10 April 2013 (UTC)


 * Not only can it be done, it is regularly done these days. If you Google "gene synthesis" you can find companies that will do it for you over the internet. Like gene sequencing, the price has dropped dramatically over the past 10 years, though it is still relatively more expensive than sequencing. --Mr.98 (talk) 23:50, 10 April 2013 (UTC)

Rabies-like symptoms in ducks
A friend of mine was pursued by an aggressive duck apparently intent on attacking, in a manner described as being reminiscent of rabies. Only mammals have rabies, though; can any diseases cause rabies-like symptoms in ducks? הסרפד (call me Hasirpad) (formerly R——bo) 22:52, 10 April 2013 (UTC)


 * Birds can be aggressive, especially when defending their nesting areas. Geese are notorious for attacking people.  See Friendly Persuasion.  RNealK (talk) 23:14, 10 April 2013 (UTC)
 * Sorry, I didn't provide all the details of the circumstances, which make the above explanation unlikely:
 * Would ducks nest in high-traffic public parks? Would a provoked duck pursue the provoker—presumably well past her nesting grounds? הסרפד  (call me Hasirpad) (formerly R——bo) 23:45, 10 April 2013 (UTC)
 * Not only mammals can get rabies, it can infect any warm blooded animal, including birds, however apparently birds have only been infected in experiments and not found in the wild. I saw a video on YouTube of a pelican eating a seagull and the explanation someone gave is that there is a rabies like disease that pelicans can get, so maybe it wasn't rabies, but something rabies like. In Australia, there is no actual rabies virus in the wild, but we are warned about fruit bats in particular because they can carry rabies like diseases. I just did a quick Google and it appears to be this Australian bat lyssavirus: closely related to rabies. Maybe there's something similar in birds. Vespine (talk) 23:51, 10 April 2013 (UTC)
 * Having said that, I also think you don't need rabies or any rabies like disease to explain an aggressive duck, maybe it was just an aggressive duck? There are plenty of aggressive dogs and most don't have rabies too. Vespine (talk) 23:53, 10 April 2013 (UTC)
 * Once, when sitting on the ground in a public park, I was mobbed by ducks that wanted my White Castle hamburgers. Deor (talk) 00:29, 11 April 2013 (UTC)
 * Let me guess: To get even with them for attacking, you gave it to them. ←Baseball Bugs What's up, Doc? carrots→ 01:52, 11 April 2013 (UTC)
 * More or less. While I was fighting some of them off with my left hand, others managed to snatch a burger from my right hand. At that point, I gave up.Deor (talk) 10:44, 11 April 2013 (UTC)


 * Yes, land and waterfowl will nest in public parks. Yes, they can be very aggressive, especially given they nest on the ground.  Swans have killed people and there are stories of rapes.  Turkey attacks were a big item in NJ last summer in various municipalities.  A girlfriend of mine was terrified of ducks, and she would murmur "the ducks... the ducks..." like the ending of Apocalypse Now.  My younger sisters went to the Schuykill to feed the ducks popcorn and were attacked and bitten and left in tears.  Male ducks gang up on and rape females, sometimes drowning them in the process.  Remember, these little monsters are just velociraptors with beaks instead of teeth. μηδείς (talk) 17:45, 11 April 2013 (UTC)
 * Birds are mean sons of bitches. Like Medeis says, they are the only living dinosaurs. Shadowjams (talk) 20:56, 11 April 2013 (UTC)
 * Why didn't jurassic park have any giant rabid ducks that would have been cool.165.212.189.187 (talk) 17:30, 12 April 2013 (UTC)
 * There were duck relatives at the end of the Cretaceous, but not during the Jurassic. See. μηδείς (talk) 03:10, 13 April 2013 (UTC)