category archives: science

non-invasive imaging of the plant water transport system using x-ray microCT

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it’s been rather quiet in the blog lately, so i thought i’d share a peek into what we’ve been up to at work:

Hydraulic vulnerability analysis using X-ray microCT
MicroCT cross section of a Eucalyptus stem. One of the major points of critique for hydraulic measurements of xylem vulnerability and embolism is that they are destructive measurements. In contrast, non-invasive imaging has made it possible to observe xylem function and the spread of embolism in living, intact plants without destructive sampling and associated artefacts.

In collaboration with Iain Young and Richard Flavel at the University of New England, Armidale, we recently scanned the stems of young Eucalyptus trees at high resolution using X-ray Micro Computed Tomography (microCT) to visualize the loss of hydraulic function at increasing levels of drought. [more...]

how to print a timestamp with periodic output from WinWedge

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how to print a timestamp with periodic output from WinWedge WinWedge is a simple tool to obtain periodic readouts through a serial RS-232 or COM interface (e.g. from an analytical balance). unfortunately, though, obtaining a timestamp for every data point is not as intuitive as it could be.
here’s how you can automatically add a timestamp to your periodic output with WinWedge (tested with WinWedge32 Std. V3.0).

let’s assume that you’ve already configured the basic communication (“Port” – “Settings”) and timer settings (“Define” – “Serial Output Strings” > “Interval (ms)” and “Timer Controlled Output String”). [more...]

[categories: computers & technology, science] [tags: , ]

algal collection in living pictures [lytro]

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algal collection in living pictures [lytro] the algal collection of the department of botany (university of innsbruck, austria) is an extremely photogenic subject. i published some pictures of the collection a few years ago, one of which has since been awarded “science image” by our university’s biannual magazine.

now, i’m happy to present the first interactive “living pictures” of the collection, taken with a lytro lightfield camera.


(lytro living picture: click to refocus, click&drag for perspective shift)
(view on lytro.com

somehow, it’s fascinating that you can tell these (mostly) single-celled organisms apart by the macroscopic shape of their cell colonies.

more pictures are waiting for you in my new lytro album: algal collection

mars simulation tweetup at the dachstein ice cave, austria [photos]

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here are some pictures from the first austrian #marstweetup – a twitter event that gave 16 space-enthusiastic twitter users from all over europe a deeper insight in to the ongoings of a live mars simulation. the event took place inside the world’s largest accessible ice cave in dachstein, austria.


[more...]

[categories: computers & technology, photo, science] [tags: , ]

sterile plant culture

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the tip of a carnation shoot (dianthus sp.) is taken and ridded of all the leaves, except the primordial leaves

about one year ago, i took part in a laboratory class where we learned various methods related to artificial plant reproduction.
one of the exercises was to create meristem cultures from a carnation plant (dianthus sp.), under sterile conditions.

from each shoot of the plant, we removed the developing leaves on the tip, almost down to the meristem (the few primary cells that constantly divide into more cells). we stopped the exraction at the smallest primordial leaves, placed the tiny piece of plant material on culture medium (in test tubes, under sterile conditions), added a cap to the tube, and sealed it with parafilm.
the following weeks, it was positioned beneath a daylight lamp, and after the experiment was finished, i asked if i could take one specimen home with me.

march 16th: meristem culture about two months after the procedure. development of root tissue.

considering that it’s an almost completely closed system, i didn’t expect little william the carnation to last this long: the plant grew and grew until it reached the top, and i’ve just recently placed it upside down, so that it could grow “upwards” again.

two notes:
most people don’t consider that, in darkness, plants need to “breathe” just as animals do (as in: use O2 and release CO2), so the gas contents are probably still OK, if only limited. (also, i’m assuming that parafilm isn’t able to stop slow diffusion of gas molecules completely.)

supposedly getting low on fresh nutrients, the plant seems to have given up on the lower leaves so that it could develop new ones. the old, withered leaves do not decompose since there aren’t any microorganisms in the system.

photos: sterile plant culture

[categories: photo, science] [tags: , , ]

missing link no longer missing? early primate provides evolution clues

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thumbnail picture
taken from original
publication

scientists say they’ve found and studied a complete fossil of a primate that is likely to be an early ancestor of the human species. this exciting finding may be an important “snapshot” from the time when humans, apes and monkeys diverged from the other primates such as lemurs.

a brand-new documentary, titled “the link” is set to air soon in the US, UK, norway and germany. a trailer and air dates are presented at revealingthelink.com.

Early Primate Provides Evolution Clues
Scientists say a 47-million-year-old fossil found in Germany may be a key link to explaining the evolution of early primates and, perhaps, telling them about developments that led to modern human beings. [more...]

[category: science] [tags: ]

coblation conchotomy – the end of a blocked nose era

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warning: the following links and videos show some things that you are probably going to find gross. watch them at your own risk.

someone once told me, that buddhism says “once a year, you should do something you’ve never done before”.
i’ve had so many different things inside my nose lately that i think that counts for 2009.

some time ago, i discovered two fairly large masses in my nostrils.
searching for information on the internet returned lots of websites that were talking about either nasal haematoma (see photo quiz of the aafp, pictures at meduweb) or haemangioma (e.g. blog post and corresponding picture).
it wasn’t likely to be a haematoma because that is usually caused by being hit on your nose (which i hadn’t been), and the “balloons” in these pictures originated in the septum, while mine seemed to originate on the opposite side.. i didn’t know about the tumours, though.

i was relieved to hear my ENT doctor tell me that i just had very large turbinates (or nasal conchae). turns out this is why my nose had been more or less constantly congested for several years.

in terms of treatment, i had two choices:
[more...]

[categories: general, science] [tags: ]