Ascidias invasoras ¿un problema ambiental o una ventana de oportunidades?

Las ascidias son animales bénticos marinos presentes en las costas de todo el mundo; crecen prácticamente sobre cualquier tipo de superficie. Esta característica de fijación les permite ser transportadas accidentalmente, a otras áreas que no son su hábitat natural, por lo que se les conoce como especies exóticas/invasoras. Esto puede causar problemas ecológicos al alterar la diversidad de las especies nativas, ocasionando algunas repercusiones graves en actividades como la pesca y el cultivo de algunas especies, como ocurre en la bahía de La Paz, ya que en años recientes la llegada de la ascidia colonial Distaplia stylifera ha ocasionado problemas severos en maricultivos. Las ascidias producen compuestos químicos conocidos como metabolitos secundarios, muchos de ellos tienen diversas propiedades bioactivas, como antimicrobianos, antivirales, antitumorales, entre otras. Además, las ascidias tienen un significativo contenido de proteína, glucógeno y minerales, en comparación con otros alimentos de origen animal, por lo que las ascidias invasoras, como D. stylifera, representan un nicho de oportunidad para evaluar su potencial de aprovechamiento convirtiendo de esta forma, un problema ambiental en una ventana de oportunidades como fuente de compuestos con actividad biológica y nutritivas útiles en diversas ramas de la industria, principalmente la farmacéutica y la alimentici

Core-less Multiphase Converter with Transformer Coupling

A coupled multiphase converter where the coupling among the phases is done using core-less planar transformers is presented in this paper. Operating principle of the transformer-coupled converter has been presented previously in the literature and in this paper this concept is applied to develop a core-less converter. Two prototypes operating at high frequency (4 MHz), with low profile (3 mm - 4 mm) and 60 W of output power, with two different core-less transformers are presented. Main advantages of applying this concept at high frequency are size reduction and operation with core-less transformers. This topology can be considered as a dc-dc transformer and applications for this topology can be `dc-dc transformers' for two-stage power supply systems and voltage scaling power supplies

Differential leukocyte expression of IFITM1 and IFITM3 in patients with severe pandemic influenza A(H1N1) and COVID-19

Interferon-induced transmembrane (IFITM) proteins mediate protection against enveloped viruses by blocking membrane fusion at endosomes. IFITM1 and IFITM3 are crucial for protection against influenza, and various single nucleotide polymorphisms altering their function have been linked to disease susceptibility. However, bulk IFITM1 and IFITM3 mRNA expression dynamics and their correlation with clinical outcomes have not been extensively addressed in patients with respiratory infections. In this study, we evaluated the expression of IFITM1 and IFITM3 in peripheral leukocytes from healthy controls and individuals with severe pandemic influenza A(H1N1) or coronavirus disease 2019 (COVID-19). Comparisons between participants grouped according to their clinical characteristics, underlying disease, and outcomes showed that the downregulation of IFITM1 was a distinctive characteristic of severe pandemic influenza A(H1N1) that correlated with outcomes, including mortality. Conversely, increased IFITM3 expression was a common feature of severe pandemic influenza A(H1N1) and COVID-19. Using a high-dose murine model of infection, we confirmed not only the downregulation of IFITM1 but also of IFITM3 in the lungs of mice with severe influenza, as opposed to humans. Analyses in the comparative cohort also indicate the possible participation of IFITM3 in COVID-19. Our results add to the evidence supporting a protective function of IFITM proteins against viral respiratory infections in humans.Introduction Methods - Human samples - IFITM expression in humans - Influenza infection in mice - IFITM expression in mice - Cytokine levels in mouse lungs - Study approval - Statistical analysis Results - Participant characteristics - IFITM1 and IFITM3 in patients with severe pandemic influenza A(H1N1) - High-dose influenza A (H1N1) virus infection downregulates IFITM expression in mice - IFITM1 and IFITM3 in severe COVID-19 Discussio

Magnetic operations: a little fuzzy physics?

We examine the behaviour of charged particles in homogeneous, constant and/or oscillating magnetic fields in the non-relativistic approximation. A special role of the geometric center of the particle trajectory is elucidated. In quantum case it becomes a 'fuzzy point' with non-commuting coordinates, an element of non-commutative geometry which enters into the traditional control problems. We show that its application extends beyond the usually considered time independent magnetic fields of the quantum Hall effect. Some simple cases of magnetic control by oscillating fields lead to the stability maps differing from the traditional Strutt diagram.Comment: 28 pages, 8 figure

Regeneración de oreomunnea mexicana (Juglandaceae), una especie relicto, amenazada del bosque de niebla de sierra juárez, oaxaca, México

Oreomunnea mexicana (Stand.) J.F. Leroy is a relict species, threatened and a key species for cloud ecosystem functionof the Sierra Juárez, Oaxaca, the most extensive and best conserved in Mexico. This study includes a diagnostic on two critical stages of the process of population regeneration of O. mexicana. To this end, it analyzed the: 1) production, dispersion, viability and germination of seeds, 2) effect of predation on the growth and survival of the seedlings, and 3) effect of environmental variables (soil, canopy structure and solar radiation) on the regeneration of the species. The study was made from 2014 to 2015 in the cloud forest of Santiago Comaltepec, Oaxaca, Mexico, in two locations (San Bernardo and El Orquidiario). Differences in seed production were found between years and between locations, as well as low seed viability and a high percentage of seed parasitism. The establishment and growth of the seedlings are subject to find suitable microhabitats, since seedlings have specific illumination and soil requirements. The high edaphic specificity faced by the species could be a key factor for its fragmented and discontinuous distribution in Sierra Juárez. Further population regeneration studies are recommended to increase knowledge of the species and thereby achieve its conservation. © 2019, Instituto de Ecologia, A.C. All rights reserved

Clinical consequences of BRCA2 hypomorphism

Altres ajuts: Asociación Española contra el Cáncer (LABAE16020PORTT)Altres ajuts: Asociación Española contra el Cáncer (ERAPERMED2019-215)The tumor suppressor FANCD1/BRCA2 is crucial for DNA homologous recombination repair (HRR). BRCA2 biallelic pathogenic variants result in a severe form of Fanconi anemia (FA) syndrome, whereas monoallelic pathogenic variants cause mainly hereditary breast and ovarian cancer predisposition. For decades, the co-occurrence in trans with a clearly pathogenic variant led to assume that the other allele was benign. However, here we show a patient with biallelic BRCA2 (c.1813dup and c.7796 A > G) diagnosed at age 33 with FA after a hypertoxic reaction to chemotherapy during breast cancer treatment. After DNA damage, patient cells displayed intermediate chromosome fragility, reduced survival, cell cycle defects, and significantly decreased RAD51 foci formation. With a newly developed cell-based flow cytometric assay, we measured single BRCA2 allele contributions to HRR, and found that expression of the missense allele in a BRCA2 KO cellular background partially recovered HRR activity. Our data suggest that a hypomorphic BRCA2 allele retaining 37-54% of normal HRR function can prevent FA clinical phenotype, but not the early onset of breast cancer and severe hypersensitivity to chemotherapy