Spectral reflectance as a function of wavelength for toes of a) <i>A. callidryas</i> and b) <i>H. arborea</i>.

<p>Spectra were calculated from HSD data cubes from selected regions of interest. In both species additional characteristic absorption bands were found in the region of 520 to 580/NIR spectrum was calculated for a homogeneous area of interest consisting of 54 (<i>Agalychnis callidryas</i>) and 223 pixels <i>(Hyla arborea)</i>.</p

Spectral reflectance of dorsal coloration as a function of wavelength for a+b) <i>Agalychnis callidryias</i>, c+d) <i>Litoria caerulea</i> and e+f) <i>Hyla arborea</i>.

<p>Spectra were calculated from HSD data cubes from selected regions of interest. Shown are both reflectance in a+c+e) from 400 to 1000 nm (VIS and NIR) and b+d+f) in the range from 1000–2500 nm (SWIR). The VIS/NIR spectrum was calculated for a homogeneous area of dorsal skin from 4794, 246 and 443 pixels for <i>Litoria caerulea</i>, <i>Agalychnis callidryas</i> and <i>H. arborea</i> respectively. The SWIR spectrum was calculated for a homogeneous area of dorsal skin from 980, 362 and 273 pixels.</p

<i>Agalychnis callidryas</i> (A+E), <i>Litoria caerulea</i> (B+F) and <i>Hyla arborea</i> (C,D+G,H).

<p>Images acquired by digital color (left column) or red-edge photography (right column). Red-edge photographs (E–H) have been acquired by using a “two” channel camera (Red channel: Red+IR; Blue channel: blue) Canon EOS Digital Rebel XSi modified red-edge camera with removed hot-mirror substituted by maxmax.com, Canon 85 mm telephoto lens. (As the green pixels are missing (or very dark), overall images G and H were slightly brightness corrected). Color photographs (A–D): Image acquisition performed with a Canon EOS 400D camera.</p

Hyperspectral imaging.

<p>Images of <i>Litoria caerulea</i> (A), <i>Agalychnis callidrya</i>s (B) and <i>Hyla arborea</i> (C) are shown for selected bands from the acquired hyperspectral cubes in the visible and NIR (460, 550, 640 and 800 nm).</p

Hyperspectral imaging.

<p>Images of <i>Litoria caerulea</i> (A), <i>Agalychnis callidrya</i>s (B) and <i>Hyla arborea</i> (C) are shown for selected bands from the acquired hyperspectral cubes in the NIR and SWIR SWIR (1124, 1212, 1289, 1472 and 1680 nm).</p

Normalized red-edge images of (A) <i>Agalychnis callidryas</i>, (B) <i>Litoria caerulea</i> and (C) <i>Hyla arborea</i> using a pseudo-coloration color scheme.

<p>The color index is given in figure(see equation 1+2). Raw images were acquired using a modifed Canon EOS Rebel XSi CCD camera which a optimized CCD sensitivity (D), in which the red channel is limited to the red-edge range of the spectrum (based on data provided by maxmax.com).</p

Hyperspectral imaging of three anuran species.

<p>(A) Hyperspectral imaging setup to acquire spectra and monochromatic images of a frog (2) and a reflectance standard (1) for wavelengths in the VIS, NIR and SWIR range of the spectrum. Images were acquired using two hyperspectral cameras (3 and 4) whereby the images were taken in a two pass setup. The complete setup is mounted on a solid aluminium stand (7). The first camera (3) allows to acquire a stack of hyper spectral images in the VIS and NIR (400 to 1000 nm). The second camera (4) acquires a stack of hyperspectral images in the SWIR (1000 to 2500 nm). Each camera can be driven by a stepping motor (6) along the axis of the metal bar seprateley during image acquisition in push-broom mode. Cameras and the moving stage were connected to a desktop computer (5), both controlling image acquisition and the moving-stage. Frogs (2) are imaged while sitting directly beside a 50% reflection standard (1). Illumination is provided using a halogen lamp (10) which ensured a sufficient amount light both in VIS, NIR and SWIR (8). (B) Exemplary area of interest used to calculate the reflectance spectra of <i>Agalychnis callidryas</i>. (C) Photo of the two hyperspectral cameras mounted on the moving stage.</p

Open-source, vendor-independent, automated multi-beat tissue Doppler echocardiography analysis

Current guidelines for measuring cardiac function by tissue Doppler recommend using multiple beats, but this has a time cost for human operators. We present an open-source, vendor-independent, drag-and-drop software capable of automating the measurement process. A database of ~8000 tissue Doppler beats (48 patients) from the septal and lateral annuli were analyzed by three expert echocardiographers. We developed an intensity- and gradient-based automated algorithm to measure tissue Doppler velocities. We tested its performance against manual measurements from the expert human operators. Our algorithm showed strong agreement with expert human operators. Performance was indistinguishable from a human operator: for algorithm, mean difference and SDD from the mean of human operators’ estimates 0.48?±?1.12 cm/s (R2?=?0.82); for the humans individually this was 0.43?±?1.11 cm/s (R2?=?0.84), ?0.88?±?1.12 cm/s (R2?=?0.84) and 0.41?±?1.30 cm/s (R2?=?0.78). Agreement between operators and the automated algorithm was preserved when measuring at either the edge or middle of the trace. The algorithm was 10-fold quicker than manual measurements (p?</p

Frame rate required for speckle tracking echocardiography: A quantitative clinical study with open-source, vendor-independent software

BackgroundAssessing left ventricular function with speckle tracking is useful in patient diagnosis but requires a temporal resolution that can follow myocardial motion. In this study we investigated the effect of different frame rates on the accuracy of speckle tracking results, highlighting the temporal resolution where reliable results can be obtained.Material and methods27 patients were scanned at two different frame rates at their resting heart rate. From all acquired loops, lower temporal resolution image sequences were generated by dropping frames, decreasing the frame rate by up to 10-fold.ResultsTissue velocities were estimated by automated speckle tracking. Above 40 frames/s the peak velocity was reliably measured. When frame rate was lower, the inter-frame interval containing the instant of highest velocity also contained lower velocities, and therefore the average velocity in that interval was an underestimate of the clinically desired instantaneous maximum velocity.ConclusionsThe higher the frame rate, the more accurately maximum velocities are identified by speckle tracking, until the frame rate drops below 40 frames/s, beyond which there is little increase in peak velocity. We provide in an online supplement the vendor-independent software we used for automatic speckle-tracked velocity assessment to help others working in this field.</p

Phenotypes and growth performances at high CO₂ and after transition to ambient air.

<p>(<b>A</b>) Plants were first grown in 1% CO₂ (HC) for eight weeks to stadium 5.1 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042809#pone.0042809-Boyes1" target="_blank">[25]</a>, then transferred to ambient air (LC; 0.038% CO₂) and monitored for another 2 weeks. For more detailed time courses see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042809#pone.0042809.s001" target="_blank">Figure S1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042809#pone.0042809.s002" target="_blank">Figure S2</a>. (<b>B</b>) Absolute rosette growth rates of photorespiratory mutants before and after transfer to LC. Shown is the projected rosette area (A_PT) as calculated from automated image acquisition and analysis using the phenotyping platform GROWSCREEN FLUORO. Plants were transferred to LC before reaching stadium 5.1 to allow comparability with the DISP-based growth analysis (shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042809#pone-0042809-g005" target="_blank">Figure 5</a>) of young developing leaves before and after transfer. Monitoring started 11 days after picking for a period of 10 days in HC conditions (stadium 1.04). Next, plants were transferred to LC and monitored for another 7 days. Data points represent mean values ± SD from 8 individual plants.</p