Adaptive Feature Extraction for Blood Vessel Segmentation and Contrast Recalculation in Laser Speckle Contrast Imaging

Microvasculature analysis in biomedical images is essential in the medical area to evaluate diseases by extracting properties of blood vessels, such as relative blood flow or morphological measurements such as diameter. Given the advantages of Laser Speckle Contrast Imaging (LSCI), several studies have aimed to reduce inherent noise to distinguish between tissue and blood vessels at higher depths. These studies have shown that computing Contrast Images (CIs) with Analysis Windows (AWs) larger than standard sizes obtains better statistical estimators. The main issue is that larger samples combine pixels of microvasculature with tissue regions, reducing the spatial resolution of the CI. This work proposes using adaptive AWs of variable size and shape to calculate the features required to train a segmentation model that discriminates between blood vessels and tissue in LSCI. The obtained results show that it is possible to improve segmentation rates of blood vessels up to 45% in high depths (≈900 μm) by extracting features adaptively. The main contribution of this work is the experimentation with LSCI images under different depths and exposure times through adaptive processing methods, furthering the understanding the performance of the different approaches under these conditions. Results also suggest that it is possible to train a segmentation model to discriminate between pixels belonging to blood vessels and those belonging to tissue. Therefore, an adaptive feature extraction method may improve the quality of the features and thus increase the classification rates of blood vessels in LSCI

Ultra-diluted bioactive compounds enhance energy storage and oocyte quality during gonad conditioning of Pacific calico scallop Argopecten ventricosus (Sowerby II, 1842)

WOS:000591249000001Ultra-diluted bioactive compounds have emerged as an alternative to enhance marine organism performance and to improve broodstock gonad maturation. This study evaluated for the first time the effect of three homeopathically ultra-diluted bioactive compounds (HUBC's) authorized by the health authority as medicines for humans, on the general reproductive physiology of Argopecten ventricosus, a commercially important scallop species. The experiment included three HUBC's treatments at centesimal dilution assessed in triplicate under laboratory conditions, T1: PaV-30C + PhA-30C, T2: PaV-30C + SiT-30C, and T3: ViT-30C, and a non-treated field reference group (FRG) maintained in aquaculture facilities as reference. The bioenergetics of scallop reproduction and oocyte quality increased with the three HUBC treatments, but particularly in those treated with T2. The organisms treated with T3 showed not only the highest proliferation of vitellogenic and post-vitellogenic oocytes but also the greatest oxidative damage in tissues and oocytes. In contrast, the scallops from T1 and T2 showed less oxidative damage. The results suggest that ultra-diluted formula T2 is a potential alternative to optimize A. ventricosus gonad ripening, food-nutrient management and oocyte quality because although T3 allowed accelerating the gametogenesis process, it increased oxidative damage. This study could help to improve gonad broodstock condition and larval yield of this species in hatcheries