Ecosistemas de las profundidades marinas: Reservorio privilegiado de la biodiversidad y desafíos tecnológicos

30 páginasFinancial support of the BBVA FoundationPeer reviewe

The ecology of deep-sea Holothurians

SIGLEAvailable from British Library Document Supply Centre- DSC:DX84336 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Does the Variability of Other Comprehensive Income (OCI) Play a Role in the Determination of Cost of Debt, Capital Structure and Credit Ratings?

In this paper, we focus on the usefulness of other comprehensive income (OCI) to debt investors. We conceptualize OCI’s usefulness to be its risk relevance. We hypothesize that credit risk is associated with OCI volatility and so we contribute to the debate whether this volatility is viewed by creditors as capturing useful information about debt risk or just “noise.” Specifically, we consider whether OCI’s volatility that is linked to accounting standards in the recent two decades is associated with cost of debt, non-price terms of debt contracting (i.e. covenants, security), capital and maturity structure, and credit ratings. We construct three samples to conduct our tests: (1) a new loan sample from Dealscan and (2) a comprehensive sample from COMPUSTAT and (3) credit ratings sample. We find strong evidence that higher volatility of OCI is associated with a higher cost of debt, higher likelihood of collateral requirement, and stronger credit rationing (lower use of debt). We also find statistically significant but economically weak evidence that OCI volatility is related to shorter debt maturity and lower credit ratings. Overall, our evidence suggests that OCI volatility provides useful information to credit markets and shapes debt contracting and the firm’s capital structure accordingly

Gebrukothuria profundus, a new genus and species of laetmogonid holothurian (Elasipodida, Laetmogonidae) from around the Crozet Plateau in the Southern Indian Ocean

A new genus and species of laetmogonid holothurian (Elasipodida, Laetmogonidae), collected from around the Crozet Plateau in the Southern Indian Ocean, is described. It differs from other members of the family in that the body wall lacks the wheel-shaped calcareous deposits completely. Instead only rods are present. The genus is also distinguished by the combination of other morphological characters lacking in other known genera: absence of circum-oral and ventrolateral papillae together with development of midventral tube feet. All other members of the family Laetmogonidae are known to have wheel-shaped deposits, therefore diagnosis of the family is refined

Design of Virtual Tutoring Agents for a Virtual Biology Experiment

Virtual learning environments (VLEs) may possess many advantages over traditional teaching methods in skills training that offer empowerment of constructing the skills by freely exploring a VLE. However, a conflict between the free exploration and ensuring the learning tasks tackled emerges in the learning process. A strategy to balance the conflict is to employ virtual tutoring agents to scaffold the learning tasks. This research has been carried out to investigate the issues of design and utility of a virtual tutoring agent system in a VLE to allow higher education (university based) students to practise immunology laboratory experiments, which simulates a well known immunochemical assay in the Life Sciences area, namely a Radio Immunoassay. This paper discusses the classification of category of the virtual agents in a VLE and focuses on the design of tutoring agents. Three types of the tutoring agents have been selected and implemented in the Radio Immunoassay simulation. The considered points in programming the virtual tutoring agents and their tasks are presented in this paper. A formative evaluation studies have been carried out and discussed to verify the designed virtual tutoring agents are satisfied to the target students' needs. Keywords Design of virtual tutoring agent, agent-based virtual learning environments, agent-based virtual environment for biology experiment, agent-based training software in biology, intelligent virtual laboratory, interactive learning software

Improving the estimation of deep-sea megabenthos biomass: dimension to wet weight conversions for abyssal invertebrates

Deep-sea megafaunal biomass has typically been assessed by sampling with benthic sledges and trawls, but non-destructive methods, particularly photography, are becoming increasingly common. Estimation of individual wet weight in seabed photographs has been achieved using equations obtained from measured trawl-caught specimens for a limited number of taxa. However, a lack of appropriate conversion factors has limited estimation across taxa encompassing whole communities. Here we compile relationships between measured body dimensions and preserved wet weights for a comprehensive catalogue of abyssal epibenthic megafauna, using ~47,000 specimens from the Porcupine Abyssal Plain (NE Atlantic) housed in the Discovery Collections. The practical application of the method is demonstrated using an extremely large dataset of specimen measurements from seabed photographs taken in the same location. We also collate corresponding field data on fresh wet weight, to estimate the impact of fixation in formalin and preservation in industrial denatured alcohol on the apparent biomass. Taxa with substantial proportions of soft tissues lose 35 to 60% of their wet weight during preservation, while those with greater proportions of hard tissues lose 10 to 20%. Our total estimated fresh wet weight biomass of holothurians and cnidarians in the photographic survey was ~20 times the previous estimates of total invertebrate biomass based on trawl catches. This dramatic uplift in megabenthic biomass has significant implications for studies of standing stocks, community metabolism, and numerical modelling of benthic carbon flows

Monoamine oxidase-A promotes protective autophagy in human SH-SY5Y neuroblastoma cells through Bcl-2 phosphorylation.

Monoamine oxidases (MAOs) are located on the outer mitochondrial membrane and are drug targets for the treatment of neurological disorders. MAOs control the levels of neurotransmitters in the brain via oxidative deamination and contribute to reactive oxygen species (ROS) generation through their catalytic by-product H2O2. Increased ROS levels may modulate mitochondrial function and mitochondrial dysfunction is implicated in a vast array of disorders. However, the downstream effects of MAO-A mediated ROS production in a neuronal model has not been previously investigated. In this study, using MAO-A overexpressing neuroblastoma cells, we demonstrate that higher levels of MAO-A protein/activity results in increased basal ROS levels with associated increase in protein oxidation. Increased MAO-A levels result in increased Lysine-63 linked ubiquitination of mitochondrial proteins and promotes autophagy through Bcl-2 phosphorylation. Furthermore, ROS generated locally on the mitochondrial outer membrane by MAO-A promotes phosphorylation of dynamin-1-like protein, leading to mitochondrial fragmentation and clearance without complete loss of mitochondrial membrane potential. Cellular ATP levels are maintained following MAO-A overexpression and complex IV activity/protein levels increased, revealing a close relationship between MAO-A levels and mitochondrial function. Finally, the downstream effects of increased MAO-A levels are dependent on the availability of amine substrates and in the presence of exogenous substrate, cell viability is dramatically reduced. This study shows for the first time that MAO-A generated ROS is involved in quality control signalling, and increase in MAO-A protein levels leads to a protective cellular response in order to mediate removal of damaged macromolecules/organelles, but substrate availability may ultimately determine cell fate. The latter is particularly important in conditions such as Parkinson's disease, where a dopamine precursor is used to treat disease symptoms and highlights that the fate of MAO-A containing dopaminergic neurons may depend on both MAO-A levels and catecholamine substrate availability

Moebius strip enterprises and expertise in the creative industries: new challenges for lifelong learning?

The paper argues that the emergence of a new mode of production – co-configuration is generating new modes of expertise that EU policies for lifelong learning are not designed to support professionals to develop. It maintains that this change can be seen most clearly when we analyse Small and Medium Size (SMEs) enterprises in the creative industries. Drawing on concepts from Political Economy - ‘Moebius strip enterprise/expertise’ and Cultural Historical Activity Theory - project-object’ and the ‘space of reasons’, the paper highlights conceptually and through a case study of an SME in the creative industries what is distinctive about the new modes of expertise, before moving on to reconceptualise expertise and learning and to consider the implications of this reconceptualisation for EU policies for lifelong learning. The paper concludes that the new challenge for LLL is to support the development of new forms expertise that are difficult to credentialise, yet, are central to the wider European goal of realising a knowledge economy

The future of auroral E-region plasma turbulence research

The heating caused by ionospheric E-region plasma turbulence has documented global implications for the energy transfer from space into the terrestrial atmosphere. Traveling atmospheric disturbances, neutral wind motion, energy deposition rates, and ionospheric conductance have all been shown to be potentially affected by turbulent plasma heating. Therefore it is proposed to enhance and expand existing ionospheric radar capabilities and fund research into E-region plasma turbulence so that it is possible to more accurately quantify the solar-terrestrial energy budget and study phenomena related to E-region plasma turbulence. The proposed research funding includes the development of models to accurately predict and model the E-region plasma turbulence using particle-in-cell analysis, fluid-based analysis, and hybrid combinations of the two. This review provides an expanded and more detailed description of the past, present, and future of auroral E-region plasma turbulence research compared to the summary report submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024–2033 (Huyghebaert et al., 2022a)