No abstract

The new colour photometric stereo camera produces images of skin and skin tumours in which the reflectance information that is related to subsurface pigment distribution is separated from the surface topographic information. The total information generated by the system, for use in visual or automated analysis, is potentially greater than that for either conventional photography or dermatoscopy alone. Its further development and broader clinical evaluation are warranted to determine its usefulness and role in a wide range of dermatological tasks, including tele-dermatology applications.

We investigated a method to quantify field-state wheat RSA in a phenotyping way, depicting the 3D topology of wheat RSA in 14d periods. The phenotyping procedure, proposed for understanding the spatio-temporal variations of root-soil interaction and the RSA dynamics in the field, is realized with a set of indices of mm scale precision, illustrating the gradients of both wheat root angle and elongation rate along soil depth, as well as the foraging potential along the side directions. The 70d was identified as the shifting point distinguishing the linear root length elongation from power-law development. Root vertical angle in the 40 mm surface soil layer was the largest, but steadily decreased along the soil depth. After 98d, larger root vertical angle appeared in the deep soil layers. PAC revealed a stable root foraging potential in the 0–70d period, which increased rapidly afterwards (70–112d). Root foraging potential, explained by MaxW/MaxD ratio, revealed an enhanced gravitropism in 14d period. No-till post-paddy wheat RLD decreased exponentially in both depth and circular directions, with 90% roots concentrated within the top 20 cm soil layer. RER along soil depth was either positive or negative, depending on specific soil layers and the sampling time.

Understanding chemistry and the effects of humic substances on plant growth is important for using organic fertilizer or soil amendment for sustainable snap bean production. The objective of this study was to characterize different fractions of humic acid (HA) derived from Leonardite and evaluate their effects on seedling growth and nutrient uptake of snap bean (Phaseolus vulgaris L.). HAs extracted from Leonardite were separated based on molecular weights into three fractions (HS1, HS2, HS3) plus sediment (SED). With direct polarization combined with spectral editing techniques, functional groups of HAs were quantified and the results indicated that HAs with low molecular weights had more O-alkyl and carboxyl C groups than those with large molecular sizes. A plant growth experiment was conducted as a randomized split-plot design with three replications and repeated for three plantings. The results show that addition of HAs was beneficial to leaf and root growth of snap bean compared with the control (no HA). Plants treated with low-molecular weight HAs had significantly greater root length, root surface area, and uptake of potassium by shoot than those treated with other HAs, while leaf growth was affected mainly by HAs with high molecular weight.

Computerised analysis on skin lesion images has been reported to be helpful in achieving objective and reproducible diagnosis of melanoma. In particular, asymmetry in shape, colour and structure reflects the irregular growth of melanin under the skin and is of great importance for diagnosing the malignancy of skin lesions. This paper proposes a novel asymmetry analysis based on a newly developed pigmentation elevation model and the global point signatures (GPSs). Specifically, the pigmentation elevation model was first constructed by computer-based analysis of dermoscopy images, for the identification of melanin and haemoglobin. Asymmetry of skin lesions was then assessed through quantifying distributions of the pigmentation elevation model using the GPSs, derived from a Laplace-Beltrami operator. This new approach allows quantifying the shape and pigmentation distributions of cutaneous lesions simultaneously. Algorithm performance was tested on 351 dermoscopy images, including 88 malignant melanomas and 263 benign naevi, employing a support vector machine (SVM) with tenfold cross-validation strategy. Competitive diagnostic results were achieved using the proposed asymmetry descriptor only, presenting 86.36 % sensitivity, 82.13 % specificity and overall 83.43 % accuracy, respectively. In addition, the proposed GPS-based asymmetry analysis enables working on dermoscopy images from different databases and is approved to be inherently robust to the external imaging variations. These advantages suggested that the proposed method has good potential for follow-up treatment.