Empirical Evaluation of Deep Learning Approaches for Landmark Detection in Fish Bioimages

In this paper we perform an empirical evaluation of variants of deep learning methods to automatically localize anatomical landmarks in bioimages of fishes acquired using different imaging modalities (microscopy and radiography). We compare two methodologies namely heatmap based regression and multivariate direct regression, and evaluate them in combination with several Convolutional Neural Network (CNN) architectures. Heatmap based regression approaches employ Gaussian or Exponential heatmap generation functions combined with CNNs to output the heatmaps corresponding to landmark locations whereas direct regression approaches output directly the (x, y) coordinates corresponding to landmark locations. In our experiments, we use two microscopy datasets of Zebrafish and Medaka fish and one radiography dataset of gilthead Seabream. On our three datasets, the heatmap approach with Exponential function and U-Net architecture performs better. Datasets and open-source code for training and prediction are made available to ease future landmark detection research and bioimaging applications

Search for light resonances decaying to boosted quark pairs and produced in association with a photon or a jet in proton–proton collisions at √s=13 TeV with the ATLAS detector

This Letter presents a search for new light resonances decaying to pairs of quarks and produced in association with a high-pT photon or jet. The dataset consists of proton–proton collisions with an integrated luminosity of 36.1 fb−1at a centre-of-mass energy of √s=13TeV recorded by the ATLAS detector at the Large Hadron Collider. Resonance candidates are identified as massive large-radius jets with substructure consistent with a particle decaying into a quark pair. The mass spectrum of the candidates is examined for local excesses above background. No evidence of a new resonance is observed in the data, which are used to exclude the production of a lepto-phobic axial-vector Z boson

The effects of stocking densities versus tank volume on the skeleton of gilthead seabream Sparus aurata in the hatchery and preongrowing phases of the production cycle

INTRODUCTION: Gilthead sea bream (Sparus aurata) production is one of the main aquaculture industries in the Mediterranean, producing 258,754 tones of seafood in 2019 (FAO, 2021). However, in recent years uncertainty regarding the profitability and the economic losses have been inevitable for many production facilities due to rapid market expansion in the 1980s followed by an oversupply establishing a lower market value in the last two decades (Llorente et al., 2020). Therefore, a focus on increasing the production value rather than increasing production quantity would be a sustainable solution to improve profitability and adjust for long-term environmental and economic goals in the EU (Llorente et al., 2020). The coupled application of Large Volumes (O/ =30-60m3) and low densities (< 16 larvae/L) has been demonstrated (Koumoundourous et al., 2004; Boglione et al., 2009; Prestinicola et al., 2013) augment the survival rate and the morphological quality of gilthead sea bream and other Sparids. However, the separate effects of density or volume, decoupled from each other has not been investigated. This knowledge will help farmers to produce subadults of higher quality to be ongrown by modulating only one of these two factors, without any need for extra economic investment, hightech solutions, or new tanks. The aim of this study was to individuate which between ‘large volume’ and ‘low density’ is the main driver in attaining high quality gilthead sea bream during both the hatchery (from eggs to juveniles) and the preongrowing (Waverage up to ~55 g). The experimental design envisaged to test the effects at a commercial scale of A) larger and smaller tank volumes on seabream, stocked at the same density; and B) higher and lower stocking densities on seabream maintained in the same tank volume. The experimented tank volumes were smaller, and the densities higher than those tested in previous studies. The choice of the experimental tank volumes (500 vs 1000 L) was based on the ubiquity of these tanks in almost every Mediterranean farm. The densities we utilized were those indicated as interesting to be tested by API (Italian Association of Fish farmers). MATERIALS & METHOD: Experimental rearing were conducted in the EcoAqua facilities at the University of Las Palmas, Gran Canaria (Spain) for the hatchery phase and at the Intituto Portugues do Mar e Atmosfera facilities in Olhão Portugal for the preongrowing phase. 3 different densities (Low Density (LD): 25 eggs/L and 5kg/m3; Medium Density (MD): 125 eggs/L and 10kg/ m3; High Density (HD): 250 eggs/L and 20kg/m3) were utilized for the hatchery and ongrowing phases respectively. Two tank volumes were tested for each density condition, in all the trials: 500L tanks (small volume) and 1000L tanks (large volume). Natural seawater was pumped into the systems and all of the rearing parameters were maintained the same for all of the conditions, save the volume or the density. Additionally, oxygen was maintained at above 70% SAT for both trials. Seabream were reared for approximately 2 months in each trial. Juveniles from the hatchery phase were whole-mount stained with Alizarin red while the sub-adults from the preongrowing cycle were radiographed. Monitoring of skeletal anomalies was done for both studies using an adapted alphanumeric code to account for skeletal elements affected and region of body in which the anomaly was located Prestinicola et al. (2013). Data was expressed in a raw matrix in order to calculate the frequencies of anomaly types found over the total amount of anomalies and a binary matrix to calculate the frequencies of individuals affected by every anomaly types. All statistical analyses and graphs were done using Python and Past 4.02 (Hammer et al., 2001). RESULTS: Strikingly the environmental parameters of varying degrees in density and volume elicited similar responses in both early juveniles and subadults. Both experimental cycles enhanced significant greater lengths, reduced opercular, jaw, and vertebral axis anomalies in LD reared seabream, while larger volumes reduced the incidence of jaw anomalies. This outcome highlights the predominant effect of environmental drivers on skeletal plasticity in this species, regardless of notable differences in genetic origin, life-stage, and ontogenetic phases (Fig. 1). The possible hypotheses (behavioral, chemo-physical, physiological, etc…) that can be formulated to explain this primary, more positive effect of low stocking density rather than the larger tank volume, are largely discussed. ACKNOWLEDGEMENT: This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreement No. 766347, BioMedAqu, ETN 766347

A Baseline for Skeletal Investigations in Medaka (Oryzias latipes): The Effects of Rearing Density on the Postcranial Phenotype

Oryzias latipes is increasingly used as a model in biomedical skeletal research. The standard approach is to generate genetic variants with particular skeletal phenotypes which resemble skeletal diseases in humans. The proper diagnosis of skeletal variation is key for this type of research. However, even laboratory rearing conditions can alter skeletal phenotypes. The subject of this study is the link between skeletal phenotypes and rearing conditions. Thus, wildtype medaka were reared from hatching to an early juvenile stage at low (LD: 5 individuals/L), medium (MD: 15 individuals /L), and high (HD: 45 individuals /L) densities. The objectives of the study are: (I) provide a comprehensive overview of the skeletal elements in medaka; (II) evaluate the effects of rearing density on specific meristic counts and on the variability in type and incidence of skeletal anomalies; (III) define the best laboratory settings to obtain a skeletal reference for a sound evaluation of future experimental conditions; (IV) contribute to elucidating the structural and cellular changes related to the onset of skeletal anomalies. The results from this study reveal that rearing densities greater than 5 medaka/L reduce the animals’ growth. This reduction is related to decreased mineralization of dermal (fin rays) and perichondral (fin supporting elements) bone. Furthermore, high density increases anomalies affecting the caudal fin endoskeleton and dermal rays, and the preural vertebral centra. A series of static observations on Alizarin red S-whole mount stained preural fusions provide insights into the etiology of centra fusion. The fusion of preural centra involves the ectopic formation of bony bridges over the intact intervertebral ligament. An apparent consequence is the degradation of the intervertebral ligaments and the remodeling and reshaping of the fused vertebral centra into a biconoid-shaped centrum

Silver-palladium Thick-film Conductors

The trends in integrated circuit packaging technology are toward high speed, high density, reliability, and low cost. These demand the improvement of material formulations and processing technology. Among the thick-film materials systems, conductor materials generally represent an important and the most expensive element. Therefore, attention has been centered on the performance of the fired metal film and its cost. Silver and palladium (Ag/Pd) conductors are important components of thick-film paste technology. Thick-film Ag/Pd conductors find applications in many aspects of electronics and electronic packaging, such as hybrid microcircuits, multichip modules, packaging for integrated microcircuits, and in passive electronic components such as multilayer capacitors, varistors, and inductors. in this paper, the performance and properties of fired Ag/Pd films are discussed through their physical and chemical aspects. the final film properties are correlated to a number of factors, including thermodynamics and kinetics of Pd oxidation during burnout and firing; chemical and physical reaction of the Ag/Pd with the ceramic substrate, organic vehicle, and solder; Ag diffusion and migration; inorganic and organic additives; powders characteristics; and paste properties