First recorded case of leucism in the velvet belly lantern shark Etmopterus spinax (Squaliformes: Etmopteridae)

The capture of a female specimen of the velvet belly lantern shark Etmopterus spinax with abnormal skin coloration is reported. The specimen was captured off northern Spain (Bay of Biscay, North-eastern Atlantic) in 2021 by bottom trawling. The lack of dermal melanophores combined with a normal retinal pigmentation, lead us to considerate the specimen as leucistic. This is the first case of leucism in E. spinax and the second record of colour aberration in the family Etmopteridae. A comprehensive updated review of published literature on albinism and leucism in chondrichthyans is also provided.En prens

Reversible holography and optical phase conjugation for image formation/correction using highly efficient organic photorefractive polymers

AbstractIn this work, we report the reversible reconstruction of holographic and distorted transmission images through the four wave mixing (FWM) technique and optical phase conjugation (OPC), an alternative method to adaptive optics, by using highly efficient Photorefractive (PR) polymers fabricated in our laboratories. These PR polymers are based on our synthesized nonlinear chromophore 4-[4-(diethylamino)-2 hydroxybenzylideneamino] benzonitrile (Dc). For the PR devices, diffraction efficiencies as high as 90% at 25wt.% doping level of Dc at an external applied electric field (Eext) around 56V/μm are achieved. The reconstruction implementation is simple, of low cost, all-optical and it is capable of recovering 90% of the original images. The real-time holographic experiments were performed at Eext of just 27V/μm, which is one of the lowest reported values. Reversible holographic imaging is showed with a rise-time around 0.35s

Circulating levels of specific members of chromosome 19 microRNA cluster are associated with preeclampsia development

Purpose: To perform serum microRNA expression profiling to identify members of chromosome 19 miRNA cluster involved in preeclampsia development. Methods: Serum chromosome 19 miRNA cluster microRNA expression profiling was evaluated at 12, 16, and 20 gestational weeks and at the time of preeclampsia diagnosis, in women who developed preeclampsia (WWD-PE; n = 16) and controls (n = 18) using TaqMan low density array plates. Results: A total of 51 chromosome 19 microRNA cluster members were evaluated. The circulating hsa-miRs 512-3p, 518f3p, 520c-3p, and 520d-3p, were differentially expressed between groups (P < 0.05). Compared with controls, serum levels of hsa-miR-518f-3p at 20 GW were useful for identifying WWD-Mild-PE (P = 0.035) and WWD-Severe-PE(P = 0.007). Conclusions: Serum hsa-miRs 512-3p, 518f-3p, 520c-3p, and 520d-3p, are differentially expressed between WWD-PE and controls and their role in the development of preeclampsia should be investigated further

Architectural Diversity of the Cuticle and Epidermis of Native and Hybrid Tomato Fruit Genotypes and the Relation to Polygalacturonase Expression

The tomato (Solanum lycopersicum L.) fruit has been widely studied because of its high consumption, nutritional value, and well-characterized genome. It also represents a good model for studying the structure and function of the cuticle, a protective film that is deposited on the surface of outer epidermal cell walls, and affects the integrity and firmness of the fruit, and, therefore, its commercialization. To evaluate the differences in their structure and function, we characterized the morphology of the cuticle and the epidermis and their relationship to firmness, brightness, weight loss, and transcript levels of polygalacturonase (PGA) in four hybrid genotypes and four native genotypes of different origins, shapes, and colors. Our results show a different architecture of the epidermis and cell wall among the genotypes. Native genotypes showed irregular-shaped epidermal cells and a thicker epidermis. Anticlinal pegs were also present to only one-third of the depth of the epidermal cells. The hybrid fruit surface was smoother compared to native genotypes, and it was associated with a higher level of brightness and a less weight loss. A negative correlation between firmness and PGA transcript levels was found. The chartreuse yellow genotype was the firmest, and it had the lowest levels of PGA expression. Meanwhile, the black genotype displayed the lowest weight loss and stem scar diameter. Our results suggest that several morphological features of the cuticle and epidermis have been modified through selection of the tomato fruit, altering quality parameters, such as weight loss and firmness

Sharing food with hyenas: a latrine of Pachycrocuta brevirostris in the Early Pleistocene assemblage of Fuente Nueva-3 (Orce, Baza Basin, SE Spain)

The Early Pleistocene archeological site of Fuente Nueva-3 (FN3) preserves some of the oldest evidence of hominin presence in Western Europe, including a huge assemblage of Oldowan tools and evidence of butchering and marrow processing of large mammal bones. Moreover, there is also evidence of the regular presence of carnivores at the site, including a small proportion of bones that show tooth marks, the majority of which can be attributed to the giant, short-faced hyena Pachycrocuta brevirostris, and there are 220 coprolites, most of them from the Upper Archeological Level. In order to identify the defecating agent, we analyze here the coprolites and compare them with other specimens from the literature and with scats from zoo spotted hyenas (Crocuta crocuta). The morphology, color, size, and chemical composition of the FN3 coprolites allow us to attribute them to the hyena P. brevirostris, which is also represented at the site by fossil specimens. In addition, we evaluate the origin of the accumulation of coprolites and discuss on the role played by the scavenging hyenas in the accumulation and modification of the bone remains unearthed at the site, which allows evaluating the contribution of the giant hyena to this Early Pleistocene site. Finally, based on the lithology of layer 5 of the Upper Archeological Level, fine sands and clays deposited in a salt-lake environment, we hypothesize that this layer may have acted as a quicksand where large-sized animals like elephants were trapped and their carcasses lured scavenging carnivores.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEJunta de AndalucíaGeneralitat de CatalunyaMinisterio de Ciencia e InnovaciónComunidad de Madridpu

A comparison of back propagation and Generalized Regression Neural Networks performance in neutron spectrometry

The process of unfolding the neutron energy spectrum has been subject of research for many years. Monte Carlo, iterative methods, the bayesian theory, the principle of maximum entropy are some of the methods used. The drawbacks associated with traditional unfolding procedures have motivated the research of complementary approaches. Back Propagation Neural Networks (BPNN), have been applied with success in neutron spectrometry and dosimetry domains, however, the structure and learning parameters are factors that highly impact in the networks performance. In ANN domain, Generalized Regression Neural Network (GRNN) is one of the simplest neural networks in term of network architecture and learning algorithm. The learning is instantaneous, requiring no time for training. Opposite to BPNN, a GRNN would be formed instantly with just a 1-pass training on the development data. In the network development phase, the only hurdle is to optimize the hyper-parameter, which is known as sigma, governing the smoothness of the network. The aim of this work was to compare the performance of BPNN and GRNN in the solution of the neutron spectrometry problem. From results obtained it can be observed that despite the very similar results, GRNN performs better than BPNN

Optimización de redes neuronales artificiales para la reconstrucción del espectro de neutrones y sus dosis equivalentes

En el presente trabajo se utilizo la metodología de diseño robusto de redes neuronales artificiales para determinar una topología óptima de red capaz de resolver con eficiencia los problemas de espectrometría y dosimetría de neutrones. Para el diseño de la topología de red optimizada se entrenaron 36 distintas arquitecturas de red en base a un arreglo ortogonal con una configuración L9(34), L4(32). Para el entrenamiento de las redes neuronales, se utilizo un código de cómputo desarrollado en el entorno de programación de Matlab, el cual automatiza el procesamiento y análisis de la información, reduciendo considerablemente el tiempo empleado en esta actividad para el investigador. Para el entrenamiento de las redes de propagación hacia adelante se utilizo un compendio de espectro de neutrones publicado por la Agencia Internacional de Energía Atómica, donde del total se utilizaron el 80% para el entrenamiento y 20% para la prueba, entrenada con un algoritmo de propagación inversa siendo los datos de entrada las tasas de conteo correspondientes a las 7 esferas del sistemas espectrométrico de esferas Bonner, como datos de salida, la red neuronal obtiene el espectro de neutrones expresado en 60 grupos de energía y se calculan de forma simultánea 15 cantidades dosimétricas

Déjà vu: on the use of meat resources by sabretooth cats, hominins, and hyaenas in the Early Pleistocene site of Fuente Nueva 3 (Guadix‑Baza Depression, SE Spain)

The late Early Pleistocene archaeological site of Fuente Nueva 3 (Orce, Guadix-Baza Depression, SE Spain), dated to ~1.4 Ma, provides evidence on the subsistence strategies of the first hominin population that dispersed in Western Europe. The site preserves Oldowan tool assemblages associated with abundant remains of large mammals. A small proportion of these remains show cut marks and percussion marks resulting from defleshing and bone fracturing, and a small proportion of bones also show tooth marks. Previous taphonomic studies of FN3 suggested that the hominins had secondary access to the prey leftovers abandoned by sabretooth cats and other primary predators. However, a recent analysis by Yravedra et al. (2021) of the frequency of anthropogenic marks and tooth marks has concluded that the hominins had primary access to the carcasses of a wide variety of ungulate prey, even though the frequency of evisceration marks is strikingly low. In this rebuttal, we analyse the patterns of bone preservation in FN3, which show that the exploitation of bone marrow by the hominins after hammerstone breakage was a usual activity at the site. Our study also reviews the evidence available on the lesser abilities of sabretooth cats for carcass processing compared to pantherine felids. This reinforces the hypothesis that primary predators provided the hominins the opportunity to scavenge sizeable chunks of meat and bone marrow of their prey carcasses before the arrival of hyaenas. Finally, we also provide new inferences on resource availability and competition intensity among the members of the carnivore guild in FN3, which reinforce our interpretation that a secondary access by the Oldowan hominins to the prey leftovers of sabretooth cats was an optimal foraging strategy in the Guadix-Baza Depression.Funding for open access publishing: Universidad Málaga/CBUA This work has been granted by projects CGL-2016-78577-P, CGL-2016-80975-P, and PID2019-111185GB-I00 of the Spanish Ministry of Science, Innovation and University, “Junta de Andalucía” (FEDER) project UMA18-FEDERJA-188, “Generalitat de Catalunya” grant GENCAT 2017SGR 859, and by Research Group RNM-146 from “Junta de Andalucía.” Funding for open access charge: Universidad de Málaga / CBU

A neutron spectrum unfolding code based on generalized regression artificial neural networks

The most delicate part of neutron spectrometry, is the unfolding process. The derivation of the spectral information is not simple because the unknown is not given directly as a result of the measurements. Novel methods based on Artificial Neural Networks have been widely investigated. In prior works, back propagation neural networks (BPNN) have been used to solve the neutron spectrometry problem, however, some drawbacks still exist using this kind of neural nets, i.e. the optimum selection of the network topology and the long training time. Compared to BPNN, it's usually much faster to train a generalized regression neural network (GRNN). That's mainly because spread constant is the only parameter used in GRNN. Another feature is that the network will converge to a global minimum, provided that the optimal values of spread has been determined and that the dataset adequately represents the problem space. In addition, GRNN are often more accurate than BPNN in the prediction. These characteristics make GRNNs to be of great interest in the neutron spectrometry domain. This work presents a computational tool based on GRNN capable to solve the neutron spectrometry problem. This computational code, automates the pre-processing, training and testing stages using a k-fold cross validation of 3 folds, the statistical analysis and the post-processing of the information, using 7 Bonner spheres rate counts as only entrance data. The code was designed for a Bonner Spheres System based on a LiI(Eu) neutron detector and a response matrix expressed in 60 energy bins taken from an International Atomic Energy Agency compilation

Aquacultural Homoeopathy: A Focus on Marine Species

Homoeopathy is an alternative medical system proposed by Samuel Hahnemann in the eighteenth century. It uses highly diluted and agitated substances that derived from plants, minerals or animals, which have shown to be effective in human medicine, agronomy, veterinary, and as a novelty, in marine aquaculture. Aquacultural homoeopathy has developed rapidly in recent years, partially motivated by the misuse of powerful drugs (hormones, antibiotics, disinfectants) that when solving a problem generate undesirable side effects. In the last 10 years, scientific articles have been published on its application in freshwater fish native to Brazil, obtaining beneficial effects on growth, survival, hepatosomatic index, development of muscle fibres and lipid content in muscle. At Centro de Investigaciones Biológicas del Noroeste (CIBNOR, Mexico: www.cibnor.mx), we have studied the effects of homoeopathy to improve the culture of economically important marine species of molluscs, fish and shrimp. In this chapter, we show a selection of different research with preliminary or advanced results, related to the use of homoeopathy and its impact on zootechnic, biochemical, genomic and transcriptomic parameters in marine molluscs, fish and crustaceans. The results obtained suggest that homoeopathy is an eco-friendly alternative applicable in aquaculture industry to improve various productive and health aspects