Twofold topological phase transitions induced by third-nearest-neighbor interactions in 1D chains

Strong long-range interactions up to third nearest neighbors may induce a topological phase transition in one-dimensional chains. Unlike the Su-Schrieffer-Heeger model, this transition from trivial to topological phase occurs with the emergence of a pseudospin valley structure and a twofold nontrivial topological phase. Within a tight-binding approach, these topological phases are analyzed in detail and it is shown that the low-energy excitations follow a modified Dirac equation. An experimental realization in a one-dimensional elastic chain, where it is feasible to tune directly the third-nearest-neighbor interaction strength, is proposed.Comment: 6 pages, 3 figure

Testimonio de las declaraciones de varios oficiales complicados en la revolución del Comandante Castillo

Declaraciones de testigos que informan respecto a un movimiento revolucionario contra el gobierno de Córdoba. Firmado por el escribano Rafael Argüell

Análisis de la transmisión de datos en VHF: limitaciones, cambio evolutivo e innovación

Las telecomunicaciones se constituyen como un pilar fundamental de la doctrina de nuestro ejército y, principalmente, en su vertiente de transmisión de datos. A lo largo del tiempo, se han ido desarrollando nuevos sistemas y medios para llevar a cabo las comunicaciones a distancia y el sistema de comunicación vía radio siempre ha tenido una importancia crucial en el enlace entre unidades. Es por ello que los distintos sistemas de radio han ido evolucionando con el objetivo de mejorar las capacidades, superando las limitaciones de sistemas previos. Este trabajo ha sido enfocado al estudio de la transmisión de datos a través del radioteléfono PR4G dentro de la sección de radio de la compañía de transmisiones de la Brigada “Guzmán el Bueno X”. Con este fin, se ha realizado una investigación y un posterior análisis sobre el funcionamiento del sistema empleado para la transmisión de datos, hallando puntos de conflicto que supongan limitaciones en el empleo de este sistema, y proponiendo mejoras que supondrían un aumento de la eficiencia de dicha sección a la hora de llevar a cabo la transmisión de datos vía PR4G. Como consecuencia del estudio realizado, se ha detectado el retraso en cuanto a los equipos informáticos, y ciertos puntos de conflicto de los modos IP del radioteléfono requieren de una innovación, en función de su relevancia. Pese a ello, el radioteléfono PR4G se constituye como un sistema sólido que permite una transmisión de datos fiable y segura.<br /

Analysis of a new begomovirus unveils a composite element conserved in the CP gene promoters of several Geminiviridae genera: Clues to comprehend the complex regulation of late genes

"A novel bipartite begomovirus, Blechum interveinal chlorosis virus (BleICV), was characterized at the genome level. Comparative analyses revealed that BleICV coat protein (CP) gene promoter is highly divergent from the equivalent region of other begomoviruses (BGVs), with the single exception of Tomato chino La Paz virus (ToChLPV) with which it shares a 23-bp phylogenetic footprint exhibiting dyad symmetry. Systematic examination of the homologous CP promoter segment of 132 New World BGVs revealed the existence of a quasi-palindromic DNA segment displaying a strongly conserved ACTT-(N7)-AAGT core. The spacer sequence between the palindromic motifs is constant in length, but its sequence is highly variable among viral species, presenting a relaxed consensus (TT)GGKCCCY, which is similar to the Conserved Late Element or CLE (GTGGTCCC), a putative TrAP-responsive element. The homologous CP promoter region of Old World BGVs exhibited a distinct organization, with the putative TATA-box overlapping the left half of the ACTT-N7 composite element. Similar CP promoter sequences, dubbed “TATA-associated composite element” or TACE, were found in viruses belonging to different Geminiviridae genera, hence hinting unsuspected evolutionary relationships among those lineages. To get cues about the TACE function, the regulatory function of the CLE was explored in distinct experimental systems. Transgenic tobacco plants harboring a GUS reporter gene driven by a promoter composed by CLE multimers expressed high beta-glucuronidase activity in absence of viral factors, and that expression was increased by begomovirus infection. On the other hand, the TrAP-responsiveness of a truncated CP promoter of Tomato golden mosaic virus (TGMV) was abolished by site-directed mutation of the only CLE present in it, whereas the artificial addition of one CLE to the -125 truncated promoter strongly enhanced the transactivation level in tobacco protoplasts. These results indicate that the CLE is a TrAP-responsive element, hence providing valuable clues to interpret the recurrent association of the CLE with the TACE. On the basis of the aforesaid direct evidences and the insights afforded by the extensive comparative analysis of BleICV CP promoter, we propose that the TACE might be involved in the TrAP-mediated derepression of CP gene in vascular tissues.

Polymerase III transcription is necessary for T cell priming by dendritic cells

Exposure to microbe-associated molecular patterns (MAMPs) causes dendritic cells (DCs) to undergo a remarkable activation process characterized by changes in key biochemical mechanisms. These enhance antigen processing and presentation, as well as strengthen DC capacity to stimulate naïve T cell proliferation. Here, we show that in response to the MAMPS lipopolysaccharide and polyriboinosinic:polyribocytidylic acid (Poly I:C), RNA polymerase III (Pol lII)-dependent transcription and consequently tRNA gene expression are strongly induced in DCs. This is in part caused by the phosphorylation and nuclear export of MAF1 homolog negative regulator of Poll III (MAF1), via a synergistic casein kinase 2 (CK2)- and mammalian target of rapamycin-dependent signaling cascade downstream of Toll-like receptors (TLRs). De novo tRNA expression is necessary to augment protein synthesis and compensate for tRNA degradation driven by TLR-dependent DC exposure to type-I IFN. Although protein synthesis is not strongly inhibited in absence of RNA Pol III activity, it compromises the translation of key DC mRNAs, like those coding for costimulatory molecules and proinflammatory cytokines, which instead can be stored in stress granules, as shown for CD86 mRNA. TLR-dependent CK2 stimulation and subsequent RNA Pol III activation are therefore key for the acquisition by DCs of their unique T cell immune-stimulatory functions.publishe

Coupled resonator acoustic waveguides-based acoustic interferometers designed within two-dimensional phononic crystals: experiment and theory

The acoustic response of defect-based acoustic interferometer-like designs, known as Coupled Resonator Acoustic Waveguides (CRAWs), in two-dimensional phononic crystals (PnCs) is reported. The PnC is composed of steel cylinders arranged in a square lattice within a water matrix with defects induced by selectively removing cylinders to create Mach-Zehnder-like (MZ) defect-based interferometers. Two defect-based acoustic interferometers of MZ-type are fabricated, one with arms oriented horizontally and another one with arms oriented diagonally, and their transmission features are experimentally characterized using ultrasonic spectroscopy. The experimental data are compared with finite element method (FEM) simulations and with tight-binding (TB) calculations in which each defect is treated as a resonator coupled to its neighboring ones. Significantly, the results exhibit excellent agreement indicating the reliability of the proposed approach. This comprehensive match is of paramount importance for accurately predicting and optimizing resonant modes supported by defect arrays, thus enabling the tailoring of phononic structures and defect-based waveguides to meet specific requirements. This successful implementation of FEM and TB calculations in investigating CRAWs systems within phononic crystals paves the way for designing advanced acoustic devices with desired functionalities for various practical applications, demonstrating the application of solid-state electronics principles to underwater acoustic devices description

Evaluation of a SUMO E2 conjugating enzyme involved in resistance to Clavibacter michiganensis subsp. michiganensis in Solanum peruvianum, through a tomato mottle virus VIGS assay

"Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial wilt and canker of tomato. Currently, no Solanum lycopersicum resistant varieties are commercially available, but some degree of Cmm resistance has been identified in Solanum peruvianurn. Previous research showed up regulation of a SUMO E2 conjugating enzyme (SCEI) transcript in S. peruvianum compared to S. lycopersicum following infection with Cmm. In order to test the role of SCEI in resistance to Cmm, a fragment of SCEI from S. peruvianum was cloned into a novel virus induced gene silencing (VIGS) vector based on the geminivirus, Tomato Mottle Virus (ToMoV). Using biolistic inoculation, the ToMoV-based VIGS vector was shown to be effective in S. peruvianum by silencing the magnesium chelatase gene, resulting in leaf bleaching. VIGS with the ToMoV_SCEI construct resulted in 61% silencing of SCEI in leaves of S. peruvianum as determined by quantitative RT-PCR. The SCEI -silenced plants showed unilateral wilting (15 dpi) and subsequent death (20 dpi) of the entire plant after Cmm inoculation, whereas the empty vector-treated plants only showed wilting in the Cmm-inoculated leaf. The SCEI-silenced plants showed higher Cmm colonization and an average of 4.5 times more damaged tissue compared to the empty vector control plants. SCEI appears to play an important role in the innate immunity of S. peruvianum against Cmm, perhaps through the regulation of transcription factors, leading to expression of proteins involved in salicylic acid dependent defense responses.

Comunicación y Gestión de Calidad: Experiencia de la Escuela de Enfermería de la Universidad de Costa Rica

This research reconstructs the process and experiences of collaborative work between the School of Nursing Information and Dissemination Commission and the advisers of the Center for Academic Evaluation of the University of Costa Rica, during the design and execution of the Strategic Plan of Communication in the period of 2021-2022, as part of the intrinsic elements of Quality Management. The objective of this systematization of experiences was to reflect on the strategies proposed and the learnings obtained from the process. For this, the methodological proposal of Jara (2012) was used. For the analysis of the experience, minutes of meetings, official records, and other documents derived from collaborative work were used. Communication planning facilitates and strengthens the achievement of the objectives related to the quality management of Higher Education, since it is a transforming element that optimizes processes, favors accountability, and generates community among the people involved.En esta investigación, se reconstruye el proceso y las experiencias del trabajo colaborativo entre la Comisión de Divulgación e Información de la Escuela de Enfermería y las asesoras del Centro de Evaluación Académica de la Universidad de Costa Rica, durante el diseño y la ejecución del plan estratégico de comunicación en el periodo 2021-2022, como parte de los elementos intrínsecos de la Gestión de la calidad. El objetivo de esta sistematización de experiencias fue reflexionar sobre las estrategias planteadas y los aprendizajes obtenidos del proceso; para ello, se utilizó la propuesta metodológica de Jara (2012). Para el análisis de la experiencia, se emplearon minutas de reuniones, oficios y otros registros documentales derivados del trabajo colaborativo. La planificación de la comunicación facilita y fortalece el logro de los objetivos vinculados con la gestión de la calidad de la educación superior, puesto que es un elemento transformador que optimiza procesos, favorece la rendición de cuentas y genera comunidad entre las personas implicadas

Microbial community in resistant and susceptible Churra sheep infected by Teladorsagia circumcincta

[EN]Gastrointestinal nematodes (GIN) are a major threat to health and welfare in small ruminants worldwide. Teladorsagia circumcincta is a nematode that inhabits the abomasum of sheep, especially in temperate regions, causing important economic losses. Given that T. circumcincta and microbiome share the same niche, interactions between them and the host are expected. Although it is known that within a sheep breed there are animals that are more resistant than others to infection by GIN, it is not known if the microbiome influences the phenotype of these animals. Under this condition, 12 sheep were classified according to their cumulative faecal egg count (cFEC) at the end of a first experimental infection, 6 as resistant group (RG) and 6 as susceptible group (SG) to T. circumcincta infection. Then, all sheep were experimentally infected with 70,000 L3 of T. circumcincta and at day 7 days post-infection were euthanized. At necropsy, gastric mucosa and gastric content from abomasum were collected to extract bacterial DNA and sequence V3-V4 region from 16S rRNA gene using Ilumina technology. After bioanalysis performed, results showed that α-diversity and β-diversity remained similar in both groups. However, resistant phenotype sheep showed a higher number of bacteria butyrate-fermenting species as Clostridium sensu stricto 1 (abundance in RG: 1.29% and in SG: 0.069%; p = 0.05), and Turicibacter (abundance in RG: 0.31% and in SG: 0.027%; p = 0.07) in gastric content but also Serratia spp in gastric mucosa (abundance in RG: 0.12% and in SG: 0.041%; p = 0.07). A trend towards a significant negative correlation between cFEC and Clostridium sensu stricto 1 abundance in gastric content was detected (r = − 0.537; p = 0.08). These data suggest that microbiome composition could be another factor associated with the development of the resistant phenotype modifying the interaction with the host and the in last instance affecting the individual risk of infection.S

Detection of a Subset of Posttranscriptional Transfer RNA Modifications in Vivo with a Restriction Fragment Length Polymorphism-Based Method

Transfer RNAs (tRNAs) are among the most heavily modified RNA species. Posttranscriptional tRNA modifications (ptRMs) play fundamental roles in modulating tRNA structure and function and are being increasingly linked to human physiology and disease. Detection of ptRMs is often challenging, expensive, and laborious. Restriction fragment length polymorphism (RFLP) analyses study the patterns of DNA cleavage after restriction enzyme treatment and have been used for the qualitative detection of modified bases on mRNAs. It is known that some ptRMs induce specific and reproducible base “mutations” when tRNAs are reverse transcribed. For example, inosine, which derives from the deamination of adenosine, is detected as a guanosine when an inosine-containing tRNA is reverse transcribed, amplified via polymerase chain reaction (PCR), and sequenced. ptRM-dependent base changes on reverse transcription PCR amplicons generated as a consequence of the reverse transcription reaction might create or abolish endonuclease restriction sites. The suitability of RFLP for the detection and/or quantification of ptRMs has not been studied thus far. Here we show that different ptRMs can be detected at specific sites of different tRNA types by RFLP. For the examples studied, we show that this approach can reliably estimate the modification status of the sample, a feature that can be useful in the study of the regulatory role of tRNA modifications in gene expression