Biology, ecology and management perspectives of overexploited deposit-feeders sea cucumbers, with focus on Holothuria tubulosa (Gmelin, 1788)

The increasing harvesting of low trophic level organisms is rising concern about the possible consequences on the ecosystem functioning. In particular, the continuous demand of sea cucumbers from the international market lead to the overexploitation of either traditionally harvested and new target species, including the Mediterranean ones. Sea cucumbers are mostly deposit feeders able to consume sedimentary organic matter and, thus, are ideal candidate for the remediation of eutrophicated sediments, like those beneath aquaculture plants. Breeding and restocking of overexploited sea cucumbers populations are well established practice for Indo-Pacific species like Holothuria scabra and Apostichopus japonicus. Some attempts have been also made for the Mediterranean species Holothuria tubulosa, but, so far, the adaptation of protocols used for other species presented several issues. We here summarize narratively the available information about sea cucumbers rearing protocols with the aim of identifying their major flaws and gaps of knowledge and fostering research about new triggers for spawning and feasible protocols to reduce the high mortality of post-settlers.

The Course Reform and Internet Teaching of New Inorganic Materials

With the continuous demand of material performance, the development of materials is rapid, and the professional curriculum teaching of “new inorganic materials” as well as its teaching methods related to the internet mandate a reform, in order to meet the needs of innovative high-quality personnel training. The update and optimization of the teaching content and methods assisted by the internet meet the needs of modern teaching and research work. More than 90% of students believe that internet teaching is conducive to the understanding of classroom knowledge and the development of innovative projects.

Optimization of Reactive Diluent for Bio-Based Unsaturated Polyester Resin: A Rheological and Thermomechanical Study

Nowadays, unsaturated polyester resins (UPR) are mainly obtained from non-renewable resources. The ever-increasing regulations and the continuous demand for more sustainability have led to extensive research towards more environmentally suitable alternatives to petroleum-based materials. However, one of the main disadvantages of bio-based UPR is their relatively high viscosity compared to petrochemical ones. In order to overcome this drawback, in this work, we investigated the possibility to lower the resin viscosity utilizing a mixture of dimethyl itaconate (DMI) and methyl methacrylate (MMA) as a reactive diluent. The effect of the DMI and MMA ratio on resin rheological properties was investigated. The optimal curing parameters were determined and all UPRs had a high gel content, which was shown to be dependent on the DMI and MMA ratio in the formulation. Furthermore, thermomechanical and mechanical properties of the resulting network were also found to be affected by the used reactive diluent mixture. A small substitution of DMI by MMA proved to be advantageous since it offers lower resin viscosity and improved mechanical properties.

Fabrication of Photothermal Film for Deicing Process Based on Gold Nano-Aggregate Encapsulated Yolk-Shell Structure

Ice accumulation on vessels, airplanes, or on the off-shore plants surfaces causes major accidents and difficulties in operation. Therefore, highly efficient and environmentally friendly materials for use as deicing surfaces are in continuous demand. Accordingly, photothermal materials have gained enormous attention owing to their outstanding performance in the removal of ice. Herein, a gold nano-aggregate yolk-shell structure (GNA-YS) was introduced as a deicing material. GNA-YS was homogeneously dispersed in photocurable polyurethane acrylate and used to fabricate a highly efficient and sunlight-responsive GNA-YS film. Upon irradiation with an 810 nm light-emitting diode (LED) (135 mW cm−2), the temperature of the GNA-YS film increased by approximately 70 °C within 2 min, which rapidly (within 6 min) melted the accumulated ice. Moreover, the GNA-YS film exhibited a temperature increase of 15 °C in a refrigerator under LED illumination for 1 min. Additionally excellent stability was confirmed through repeated experiments. The newly developed deicing GNA-YS film has prospective applicability in vessels or airplanes.

Fluorescent Materials for Monitoring Mitochondrial Biology

Mitochondria play important roles in diverse cellular processes such as energy production, cellular metabolism, and apoptosis to promote cell death. To investigate mitochondria-associated biological processes such as structure, dynamics, morphological change, metabolism, and mitophagy, there exists a continuous demand for visualizing and monitoring techniques elucidating mitochondrial biology and disease-relevancy. Due to the advantages of high sensitivity and practicality, fluorescence phenomena have been most widely used as scientific techniques for the visualization of biological phenomena and systems. In this review, we briefly overview the different types of fluorescent materials such as chemical probes, peptide- or protein-based probes, and nanomaterials for monitoring mitochondrial biology.

Venom Use in Eulipotyphlans: An Evolutionary and Ecological Approach

Venomousness is a complex functional trait that has evolved independently many times in the animal kingdom, although it is rare among mammals. Intriguingly, most venomous mammal species belong to Eulipotyphla (solenodons, shrews). This fact may be linked to their high metabolic rate and a nearly continuous demand of nutritious food, and thus it relates the venom functions to facilitation of their efficient foraging. While mammalian venoms have been investigated using biochemical and molecular assays, studies of their ecological functions have been neglected for a long time. Therefore, we provide here an overview of what is currently known about eulipotyphlan venoms, followed by a discussion of how these venoms might have evolved under ecological pressures related to food acquisition, ecological interactions, and defense and protection. We delineate six mutually nonexclusive functions of venom (prey hunting, food hoarding, food digestion, reducing intra- and interspecific conflicts, avoidance of predation risk, weapons in intraspecific competition) and a number of different subfunctions for eulipotyphlans, among which some are so far only hypothetical while others have some empirical confirmation. The functions resulting from the need for food acquisition seem to be the most important for solenodons and especially for shrews. We also present several hypotheses explaining why, despite so many potentially beneficial functions, venomousness is rare even among eulipotyphlans. The tentativeness of many of the arguments presented in this review highlights our main conclusion, i.e., insights regarding the functions of eulipotyphlan venoms merit additional study.

Multiple Boris solvers for particle-in-cell (PIC) simulation

<div> <div> <div> <p> Particle-in-cell (PIC) simulation has long been used in theoretical plasma physics. In PIC simulation, the Boris solver is the de-facto standard for solving particle motion, and it has been used over a half century. Meanwhile, there is a continuous demand for better particle solvers. In this contribution, we introduce a family of Boris-type schemes for integrating the motion of charged particles. We call the new solvers the multiple Boris solvers. The new solvers essentially repeat the standard two-step procedure multiple times in the Lorentz-force part, and we derive a single-step form for arbitrary subcycle number <em>n</em>. The new solvers give <em>n<sup>2</sup></em> times smaller errors, allow larger timesteps, but they are computationally affordable for moderate <em>n</em>. The multiple Boris solvers also reduce a numerical error in long-term plasma motion in a relativistic magnetized flow.</p> </div> </div> </div><p>Reference:</p><ul><li>S. Zenitani & T. N. Kato, <em>Multiple Boris integrators for particle-in-cell simulation</em>, Comput. Phys. Commun. <strong>247</strong>, 106954, doi:10.1016/j.cpc.2019.106954 (2020)</li> </ul>