tag archives: microscopy

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...]

stellate parenchyma [photo and animation]

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stellate parenchyma is a form of aeration tissue (aerenchyma) in plants, which helps with internal air circulation in plants. the tissue is typical of aquatic and wetland plants, and consists of cells with large intercellular spaces that allow air supply to underwater plant parts.

stellate parenchyma (aerenchyma) of juncus sp.

due to the very narrow depth of field at high magnification, the picture is actually a focus stack of 22 combined layers. to get a feeling for the three-dimensional structure of this anatomical section, check out the animation below: [more...]

[categories: nature, photo] [tags: , , , ]

the beauty of wood anatomy

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wood is one of the most important substances in the human world: it’s essential for areas as diverse as music (instruments), construction, living (furniture, heating), art (sculptures) and has a broad spectrum of other uses.
its beauty can be found anywhere along the way, from a living tree to a carefully carved toothpick. going a bit deeper, it seems to just get more and more beautiful.

sweet chestnut (castanea sativa) - year rings and wood anatomy

in this post, i’d like to show you the beauy of wood anatomy at a magnification that shows individual water transport vessels. [more...]

[categories: nature, photo] [tags: , , , ]

snippet from university: differencial interference contrast microscopy animation

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nature often keeps me busy concentrating to not just stare at something with an open mouth.
in a recent class, we looked at developmental stages of plant embryos, from the zygote to a fully grown embryo inside a mature seed.

the animation below shows a young embryo that is being formed inside the ovule (entire structure). it will grow from a single cell to a complete, viable plant embryo, and the surrounding space will be filled with nutrients and storage substances that will give the little germinating seed the best chances possible.

animation: globular embryo (arrow) in an ovule of capsella bursa-pastoris. differencial interference contrast microscopy and herr-prepared specimen
animation: globular embryo (arrow) in an ovule of capsella bursa-pastoris.
differencial interference contrast microscopy and herr-prepared specimen

there are lots more pictures available, i’ll hope to find the time to upload them.

clsm animation, or: what i did last week

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last week, i took part in a practical class dealing with specific kinds of microscopy – namely confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM).
while we’re still waiting for the results of the second part, we’ve had plenty of time to play around with the CLSM.

here’s one of the numerous animations:

it shows part of a leaf of arabidopsis thaliana, that was genetically modified in a way that makes certain structure molecules within the cell walls visible.

to be more specific, the sequences of the green fluorescent protein (GFP, originally a gene of the crystal jellyfish, aequorea victoria) and a corresponding microtubule binding domain were inserted into the plant’s DNA, so that the cell walls would emit green light when exposed to light of a particular frequency (not all cells actually produced these molecules).
autofluorescense of chloroplasts is displayed in red.

using the CLSM, about 20 images were recorded at different levels of the leaf. these layers were then rendered in an animation that highlights its tridimensionality.

the image width equals 150 μm, that’s approx. 1/7th of a millimeter.

through the microscope

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a freshwater mite (hydrachnidia), dorsal
kiss me!

last month, i’ve had the chance to work on a river sampling from upper austria. the level of biodiversity exceeded anything i had seen from tyrolean rivers*, by far…

i just had to take the time to photograph some of the animals i found in that sampling: caddisfly larvae (trichoptera) and freshwater mites (hydrachnidia).

caddisfly larvae are somewhat special because many species build little portable cases for protection. kind-of like snails, only they don’t secrete their homes, they tinker them with stuff that’s lying around on the ground, and silk.

freshwater mites, on the other hand, are …”cute little balls” with (usually) 8 legs. there are more than 1000 species just within europe, and they can be used as indicator organisms because of distinct preferences in water quality etc.

[view photos: caddisfly larvae and freshwater mites]

* which, granted, weren’t that many either

[categories: nature, photo] [tags: ]