Cytoscape v3.0.2 on Mac OS X

Cytoscape 3.0.2 was released on 1st August, a bugfix release for the 3.x series. However, there is a compatibility issue with the latest Java update from Apple resulting in Cytoscape hanging on startup. I'd followed advice found elsewhere to update to the latest Java version with no success, until I found this post from Tim Hull, outlining a simple way to check what version you have installed.

/usr/libexec/java_home -v 1.6 -exec java -version

If the output contains “xM4508”, you have the broken version. If it contains "xM4509", this is probably a different issue...

If you find that you have the bad version, you can download the updated from Apple using the links below:

The updated Java fixed the problem for me.

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Building a MicroPython heart rate monitor  biology

Pulse sensors have become popular due to their use in health-monitors like the Fitbit. The sensors used are cheap, simple and pretty reliable at getting a reasonable indication of heart rate in daily use. They work by sensing the change in light absorption or reflection by blood as it pulses through your arteries — a technique jauntily named photoplethysmography (PPG). The rising and falling light signal can be used to identify the pulse, and subsequently calculate heart rate. More

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