Influences of thermal environment on fish growth

Indexación: Scopus.Thermoregulation in ectothermic animals is influenced by the ability to effectively respond to thermal variations. While it is known that ectotherms are affected by thermal changes, it remains unknown whether physiological and/or metabolic traits are impacted by modifications to the thermal environment. Our research provides key evidence that fish ectotherms are highly influenced by thermal variability during development, which leads to important modifications at several metabolic levels (e.g., growth trajectories, microstructural alterations, muscle injuries, and molecular mechanisms). In Atlantic salmon (Salmo salar), a wide thermal range (ΔT 6.4°C) during development (posthatch larvae to juveniles) was associated with increases in key thermal performance measures for survival and growth trajectory. Other metabolic traits were also significantly influenced, such as size, muscle cellularity, and molecular growth regulators possibly affected by adaptive processes. In contrast, a restricted thermal range (ΔT 1.4°C) was detrimental to growth, survival, and cellular microstructure as muscle growth could not keep pace with increased metabolic demands. These findings provide a possible basic explanation for the effects of thermal environment during growth. In conclusion, our results highlight the key role of thermal range amplitude on survival and on interactions with major metabolism-regulating processes that have positive adaptive effects for organisms.http://onlinelibrary.wiley.com/doi/10.1002/ece3.3239/ful

Synthesis, physicochemical and photophysical characterization of 4-(1-Pyrenyl)-Butyl-α-d-mannopyranoside

Indexación: Web of Science; Scopus; Scielo.Glycolipids are biomolecules composed of a lipid chain (lipophilic) and a monosaccharide or oligosaccharide as hydrophilic group. Their chemical structure and biological role make them undoubtedly good candidates for a large and continuously growing number of biotechnological applications. Mannose is a carbohydrate present on membrane glycolipids of a wide number of pathogenic microorganisms (bacteria, fungi, protozoa, and viruses) and specifically recognized by several lectins. We synthesized a mannose derivative linked through a short methylene chain to a pyrene moiety which behaves as a surfactant, able to aggregate, and retains the photophysical properties of pyrene: showing comparable absorption and emission spectra, having lower fluorescence quantum yield and the ability to form excimer, and finally the ability to produce O-2((1)Delta(g)) with high quantum yields. Thus, this novel molecule would open future applications for detection (fluorescence) or inactivation (singlet oxygen) of bacterial pathogens, viruses, tumor cells, or particular cells.http://ref.scielo.org/pcn4d

Reinforcement learning for semi-autonomous approximate quantum eigensolver

The characterization of an operator by its eigenvectors and eigenvalues allows us to know its action over any quantum state. Here, we propose a protocol to obtain an approximation of the eigenvectors of an arbitrary Hermitian quantum operator. This protocol is based on measurement and feedback processes, which characterize a reinforcement learning protocol. Our proposal is composed of two systems, a black box named environment and a quantum state named agent. The role of the environment is to change any quantum state by a unitary matrix $\hat{U}_E=e^{-i\tau\hat{\mathcal{O}}_E}$ where $\hat{\mathcal{O}}_E$ is a Hermitian operator, and $\tau$ is a real parameter. The agent is a quantum state which adapts to some eigenvector of $\hat{\mathcal{O}}_E$ by repeated interactions with the environment, feedback process, and semi-random rotations. With this proposal, we can obtain an approximation of the eigenvectors of a random qubit operator with average fidelity over 90\% in less than 10 iterations, and surpass 98\% in less than 300 iterations. Moreover, for the two-qubit cases, the four eigenvectors are obtained with fidelities above 89\% in 8000 iterations for a random operator, and fidelities of $99\%$ for an operator with the Bell states as eigenvectors. This protocol can be useful to implement semi-autonomous quantum devices which should be capable of extracting information and deciding with minimal resources and without human intervention.Comment: 15 pages, 6 figure

Aplicación de la estadística en temáticas de administración de empresas

El presente artículo da cuenta de una experiencia de aula desarrollada en el Instituto de Educación Continua de la Universidad de Los Lagos de Osorno – Chile con alumnos y alumnas del primer año de la carrera Técnico Universitario en Administración de Empresas, quienes en el módulo de Estadística desarrollaron investigaciones en sus lugares de trabajo sobre temas propios de su profesión. Los estudiantes formaron equipos de trabajo y eligieron problemáticas relacionadas a sus carreras, luego aplicaron cuestionarios para recolectar información, presentaron los datos recopilados en tablas y gráficos de los cuales obtuvieron estadígrafos que permitieron establecer conclusiones. Para la descripción y análisis de los resultados, cada equipo realizó un informe escrito sobre la investigación. Como resultado de la experiencia se logró que los estudiantes se introdujeran en una problemática propia de su área laboral, investigaran y recopilaran información sobre el tema y pudieran visualizar a la estadística como una disciplina potencialmente útil para su formación profesional y futura vida laboral

The GIRAFFE Inner Bulge Survey (GIBS). I. Survey Description and a kinematical map of the Milky Way bulge

The Galactic bulge is a massive, old component of the Milky Way. It is known to host a bar, and it has recently been demonstrated to have a pronounced boxy/peanut structure in its outer region. Several independent studies suggest the presence of more than one stellar populations in the bulge, with different origins and a relative fraction changing across the bulge area. This is the first of a series of papers presenting the results of the Giraffe Inner Bulge Survey, carried out at the ESO-VLT with the multifibre spectrograph FLAMES. Spectra of ~5000 red clump giants in 24 bulge fields have been obtained at resolution R=6500, in the infrared Calcium triplet wavelength region at 8500 {\AA}. They are used to derive radial velocities and metallicities, based on new calibration specifically devised for this project. Radial velocities for another ~1200 bulge red clump giants, obtained from similar archive data, have been added to the sample. Higher resolution spectra have been obtained for 450 additional stars at latitude b=-3.5, with the aim of investigating chemical abundance patterns variations with longitude, across the inner bulge. In total we present here radial velocities for 6392 RC stars. We derive a radial velocity, and velocity dispersion map of the Milky Way bulge, useful to be compared with similar maps of external bulges, and to infer the expected velocities and dispersion at any line of sight. The K-type giants kinematics is consistent with the cylindrical rotation pattern of M-giants from the BRAVA survey. Our sample enables to extend this result to latitude b=-2, closer to the Galactic plane than probed by previous surveys. Finally, we find strong evidence for a velocity dispersion peak at (0,-1) and (0,-2), possibly indicative of a high density peak in the central 250 pc of the bulgeComment: A&A in pres

Adaptive random quantum eigensolver

We propose an adaptive random quantum algorithm to obtain an optimized eigensolver. Specifically, we introduce a general method to parametrize and optimize the probability density function of a random number generator, which is the core of stochastic algorithms. We follow a bioinspired evolutionary mutation method to introduce changes in the involved matrices. Our optimization is based on two figures of merit: learning speed and learning accuracy. This method provides high fidelities for the searched eigenvectors and faster convergence on the way to quantum advantage with current noisy intermediate-scaled quantum computers.Junta de Andalucía (Grants No. P20-00617 and No. US-1380840)Science and Technology Commission of Shanghai Municipality (Grant No. 2019SHZDZX01-ZX04