Structural analysis of the variable major proteins of Borrelia hermsii.

Borrelia hermsii undergoes spontaneous antigenic variation in vivo and in vitro. Serotype specificity is associated with expression of one of a family of molecular weight-variable proteins, the pI proteins. We studied the structure of the pI proteins as well as the molecular weight-invariable pII proteins of three serotypes of B. hermsii HS1: C, 7, and 21. The techniques used were one-dimensional (1-D) mapping of Staphylococcus aureus V8 protease-generated peptides and two-dimensional (2-D) mapping of alpha-chymotrypsin-generated peptides. The pI and pII proteins were isolated by excision of polypeptides from stained polyacrylamide gel electropherograms. The 1-D peptide patterns were visualized by fluorography of intrinsically [14C]leucine-labeled proteins or by silver stain. Before 2-D mapping, polypeptides in excised gel fragments were labeled with 125I in the presence of chloramine-T. We also compared the 2-D peptide maps of pI proteins, pI7 and pI21, after their surface-exposed portions were radioiodinated using 1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycoluril (Iodogen). The I-D and 2-D peptide maps demonstrated the following: (a) pI proteins of the three serotypes have few V8 protease- or chymotrypsin-generated peptides in common, and (b) pI proteins of each serotype appear to be identical. The findings suggest that pI protein variability derives from extensive differences in the amino acid sequences of these proteins

Smart and networking underwater robots in cooperation meshes : the swarms ECSEL : H2020 project

The work presented on this paper is aimed to explain the role that unmanned underwater vehicles (AUVs/ROVs) plays in the ECSEL-H2020 SWARMS project. The main goal of the project is to reduce the operational cost and increase the safety of tasks assigned to divers in these operations. This will be achieved enabling the AUVs/ROVs to work in a cooperative mesh. The challenge is to design and develop an integrated platform (a set of Software/Hardware components), incorporated into the current generation of underwater vehicles in order to improve autonomy, cooperation, robustness, cost-effectiveness, and reliability of the offshore operations. The first demonstration of the project will be performed at PLOCAN (Oceanic Platform of the Canary Islands) where these technologies will be validated on its first stage.Peer Reviewe

Ancestral Spin Information in Gravitational Waves from Black Hole Mergers

The heaviest black holes discovered through gravitational waves have masses that are difficult to explain with current standard stellar models. This discrepancy may be due to a series of hierarchical mergers, where the observed black holes are themselves the products of previous mergers. Here we present a method to estimate the masses and spins of previous generations of black holes based on the masses and spins of black holes in a binary. Examining the merger GW190521, we find that assuming black hole spins that are consistent with those of merger remnants will alter the reconstructed ancestral spins when compared to results with uninformed priors. At the same time, the inclusion of black hole spins does not significantly affect the mass distributions of the ancestral black holes.Comment: 4 pages, 2 figure

The (B0+?)+O6 system FN CMa: A case for tidal-pulsational interaction?

FN CMa is visually double with a separation of about 0.6arcsec. Sixty high-cadence VLT/UVES spectra permit the A and B components to be disentangled, as the relative contribution of each star to the total light entering the spectrograph fluctuates between exposures due to changes in seeing. Component A exhibits rapid line-profile variations, leading us to attribute the photometric variability seen by HIPPARCOS (with a derived P=0.08866d) to this component. From a total of 122 archival and new echelle spectra it is shown that component A is an SB1 binary with an orbital period of 117.55 days. The eccentricity of 0.6 may result in tidal modulation of the pulsation(s) of component Aa.Comment: 2 pages, 1 figure, IAUS 272 - Active OB Stars: Structure, Evolution, Mass Loss and Critical Limit

Welcome project : towards a new wave energy converter technology concept

Peer Reviewe

Diseño y Simulación de un Deshidratador Mixto Indirecto de Frutas/Design and simulation of an Indirect Mixed Fruit Dehydrator

En el presente estudio se determinaron las características del diseño para un Deshidratador Mixto Indirecto (DMI) con una capacidad de 50 kg. Este deshidratador está constituido por el colector solar, placa de absorción, cubierta, ducto de succión, ventilador, resistencias eléctricas, zona de secado y ducto de aireación. Los elementos fueron diseñados mediante el programa SolidWorks, que permitió la simulación mecánica y termodinámica del proceso de secado, mediante el cual se pudieron determinar las características de los elementos del equipo. Se calculó que la temperatura óptima para la deshidratación de las frutas está entre los 40 y 70 ∘C. El calor específico del compartimiento de secado fue uniforme, con un valor de 2860,8 J/(kg.K); con la ayuda del ventilador se logró homogenizar el flujo del aire a la temperatura de deshidratación: a 50∘C fue homogénea en la zona de secado. Los resultados obtenidos en la simulación vaticinan un correcto funcionamiento del equipo. The present study determined the design characteristics for an Indirect Mixed Dehydrator (IMD) with a capacity of 50 kg. The solar collector, absorption plate, cover, suction duct, fan, electric resistances, drying zone and aeration duct constitute this dehydrator. The elements were designed trough the SolidWorks program, which allowed the mechanical and thermodynamic simulation of the drying process; by which it was possible to determine the elements' characteristics of the equipment. The optimum temperature for the dehydration of fruits was between 40 and 70 ∘C. The specific heat of the drying compartment was uniform and has a value of 2860.8 J / (kg K), with the help of the fan it is possible to homogenize the air flow at the dehydration temperature: at 50 ∘C it was homogeneous in the drying zone. The results obtained in the simulation guarantee the correct functioning of the equipment. Palabras Clave: Deshidratador Mixto Indirecto, Deshidratador de Frutas, simulación mecánica y termodinámica. Keywords: Indirect Mixed Dehydrator, Fruit Dehydrator, mechanical and thermodynamics simulatio

On the characteristics of natural hydraulic dampers: An image-based approach to study the fluid flow behaviour inside the human meniscal tissue

The meniscal tissue is a layered material with varying properties influenced by collagen content and arrangement. Understanding the relationship between structure and properties is crucial for disease management, treatment development, and biomaterial design. The internal layer of the meniscus is softer and more deformable than the outer layers, thanks to interconnected collagen channels that guide fluid flow. To investigate these relationships, we propose a novel approach that combines Computational Fluid Dynamics (CFD) with Image Analysis (CFD-IA). We analyze fluid flow in the internal architecture of the human meniscus across a range of inlet velocities (0.1mm/s to 1.6m/s) using high-resolution 3D micro-computed tomography scans. Statistical correlations are observed between architectural parameters (tortuosity, connectivity, porosity, pore size) and fluid flow parameters (Re number distribution, permeability). Some channels exhibit Re values of 1400 at an inlet velocity of 1.6m/s, and a transition from Darcy's regime to a non-Darcian regime occurs around an inlet velocity of 0.02m/s. Location-dependent permeability ranges from 20-32 Darcy. Regression modelling reveals a strong correlation between fluid velocity and tortuosity at high inlet velocities, as well as with channel diameter at low inlet velocities. At higher inlet velocities, flow paths deviate more from the preferential direction, resulting in a decrease in the concentration parameter by an average of 0.4. This research provides valuable insights into the fluid flow behaviour within the meniscus and its structural influences.Comment: 20 Pages, 5 Figure