Moth Eyes

Navigating a demon-haunted world

Tech.Ed: Pimp my app

Twitter love: #auteched #arc202

If you read my Twitter feed (and, let’s be honest, it’s not like I’ve put any effort into promoting it), you may have noticed that, last week, I was at Tech.Ed. Anyway, I’ve got notes on a number of the sessions and I figured I may as well post write them up in some sort of coherent format. Some sort of coherent format – I’m working from some fairly disconnected dot points here.

The first session will be Pimp My App, presented by Shane Morris.

The user experience of an application is defined not so much by the designers as by the developers and their time frames. The specification usually defines the features – and if the user experience is simply one line in the spec – “and it should be usable”, that will define how much attention it gets during development.

One trick that designers use is the “squint” test – you squint at the page, and see what draws your eye. This should, ideally, be what your users are supposed to find.

User experience design is not primarily about graphics – graphics can set the tone, but they are the last part of the UX design.

All user interface elements need to be processed by the user, so remove all unnecessary elements – it makes it easier for the user to understand the page. Unlike in school essays, variation should be limited – the more consistent the user interface is, the easier it will be for your users to deal with it.

How many colours should you use. Scott suggested this simple test: rate your graphic design skills on a scale of one to five. Now use that many colours. Background colours should be neutral colours – white, grey, black, navy, blue or brown are good choices. Cool colours appear to recede in the user’s vision, hot colours pop forward. One good way of adding colour is to pick new shades of the same colour. Another trick is to pick an image that expresses the right sort of feeling, and select colours from that.

Some useful sites for colour selection:

Kuler, ColourLovers
These allow you to select and search colour pallets. If you select “Create” it will allow you to upload an image and select colours from that, or from a base colour.

Vischeck
Vischeck shows your UI (or image) as it would be seen by a colour-blind user – a useful check to have.

Scott also suggested a simple test for how many fonts you should use. First, rate your graphic design skills on a scale of one to five. Now, use one font.

Unwanted relationships and JPEG artifactsAlignments between document elements create relationships. This is a useful thing – but it’s no good if you create relationships between the wrong things.

There are several ways you can group elements besides groupboxes – proximity, similarity, alignment and even just by surrounding them with whitespace. You can add visual weight to an element with the use of colour, size, constrast, irregular shape, and misalignment.

This was a deservedly popular session – both the presenter and his content was great. I enjoyed it greatly and I’ve got to recommending watching Shane Morris give a talk if you ever get the chance.


August 30, 2010 at 10:32 pm Comments (3)

Photo #11 – Bush Stone-curlew

Bush stone-curlews

Burhinus grallarius, photographed on Magnetic Island.


August 15, 2010 at 9:16 pm Comments (0)

Photo #10 – Moon, Venus and Mars

This is actually my first astronomy photo – I quite like how it turned out. Photographed in Canberra, 13 August 2010.

You can click to embiggen.


August 13, 2010 at 8:42 pm Comments (0)

Rapid adaptation to temperature change… and its limits

ResearchBlogging.orgPeople often think of evolution as though natural selection were sitting around waiting for new mutations to promote or cull. But it’s not really like that. A great deal of variation exists in any population, much of which has little or no effect on the survival or reproductive success of individuals carrying that variation. However, a changing environment can alter all that.

Gasterosteus aculeatusBarrett et. al. (2010) were interested in how population of three-spine sticklebacks (Gasterosteus aculeatus) would respond to lower temperature extremes. They collected a sample of sticklebacks from both marine lagoons and freshwater lakes in British Columbia, Canada. First, they acclimated the fish to living in fresh water, as well at a consistent temperature and daylight length.

Lakes are far more variable in temperature than the oceans – they are warmer in summer and cooler in the winter – due to the smaller quantity of water which needs to gain or lose heat. Rather unsurprisingly, the researchers found that the lake-dwelling sticklebacks could tolerate significantly colder temperatures than their marine counterparts (both populations could tolerate much higher temperatures than they ever encountered in the environment). They also demonstrated that the degree of tolerance for cold extremes was heritable – even raised in the same environment, the offspring of lake-dwelling fish could tolerate lower temperatures, whereas marine sticklebacks could not (and hybrids were intermediate).

The interesting part, however, was when they got to raising populations of sticklebacks with marine ancestors in ponds, which could get even colder in the winter than the freshwater lakes. In just three generations (three years), the population evolved to tolerate temperatures 2.5°C colder than their marine forebears! This wouldn’t have been a new mutation – existing genes, already present (but perhaps rare) had become far more common in the population than they had previously been.

It wasn’t all good news for the sticklebacks, though. Genetic diversity is critical to maintaining populations, and a period of such strong natural selection will dramatically reduce a population’s diversity. Even if a population can adapt to one sudden shock, it may so deplete their genetic diversity that there won’t be any convenient alternative genes in the population when the next hit comes.

Canada temperature anomaly 2009 vs 2006-2008 from GISTEMPThe next year brought the coldest winter that part of Canada had seen for several decades, and despite all their adaptations, all three of the experimental populations were wiped out. It may be that it was just too cold, or perhaps the increased ice cover on the ponds reduced the oxygen levels in the water to below what the fish needed. Either way, it’s a grim prospect for conservation biologists if a population that seems, by all accounts, to be surviving and even adapting to the changes in its environment can suddenly hit an unpassable barrier and go extinct.

Sticklebacks have a history of being able to adapt to significantly changing temperatures over the last few millennia, and so they may have had an advantage in having genes for dealing with a changing climate already present in their populations. That may not be the case for all species, and this study has shown just how drastic effect a change in temperature extremes can have on populations.

References

Barrett, R., Paccard, A., Healy, T., Bergek, S., Schulte, P., Schluter, D., & Rogers, S. (2010). Rapid evolution of cold tolerance in stickleback Proceedings of the Royal Society B: Biological Sciences DOI: 10.1098/rspb.2010.0923

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August 7, 2010 at 9:58 pm Comments (11)