52 research outputs found

    Polarization switching in vertical-cavity surface emitting lasers observed at constant active region temperature

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    Includes bibliographical references (page 3352).Polarization switching in gain-guided, vertical-cavity, surface-emitting lasers was studied as a function of the active region temperature. We show that polarization switching occurs even when the active region temperature is kept constant during fast pulse low duty cycle operation. This temperature independent polarization switching phenomenon is explained in terms of a recently developed model

    Transient response of vertical-cavity surface-emitting lasers of different active-region diameters

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    Includes bibliographical references (pages 614-615).The multimode dynamics of vertical-cavity surface-emitting lasers with different active-region diameters was measured under subnanosecond electrical excitation (800-ps pulse duration, 100-ps risetime). The dynamics is characterized by the delayed onset of higher order modes which have a turn-on delay that is dependent on the active-region diameter and the excitation parameters. A simple model that can be used to estimate this turn-on delay for large-area devices is presented. Polarization resolved measurements show that, under this fast excitation condition, both orthogonal polarization states are isomorphic. The influence of the observed dynamics on the relative intensity noise of these devices is also discussed

    Schnurri-3 drives tumor growth and invasion in cancer cells expressing interleukin-13 receptor alpha 2

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    Interleukin 13 receptor alpha 2 (IL13Rα2) is a relevant therapeutic target in glioblastoma (GBM) and other tumors associated with tumor growth and invasion. In a previous study, we demonstrated that protein tyrosine phosphatase 1B (PTP1B) is a key mediator of the IL-13/IL13Rα2 signaling pathway. PTP1B regulates cancer cell invasion through Src activation. However, PTP1B/Src downstream signaling mechanisms that modulate the invasion process remain unclear. In the present research, we have characterized the PTP1B interactome and the PTP1B-associated phosphoproteome after IL-13 treatment, in different cellular contexts, using proteomic strategies. PTP1B was associated with proteins involved in signal transduction, vesicle transport, and with multiple proteins from the NF-κB signaling pathway, including Tenascin-C (TNC). PTP1B participated with NF-κB in TNC-mediated proliferation and invasion. Analysis of the phosphorylation patterns obtained after PTP1B activation with IL-13 showed increased phosphorylation of the transcription factor Schnurri-3 (SHN3), a reported competitor of NF-κB. SHN3 silencing caused a potent inhibition in cell invasion and proliferation, associated with a down-regulation of the Wnt/β-catenin pathway, an extensive decline of MMP9 expression and the subsequent inhibition of tumor growth and metastasis in mouse models. Regarding clinical value, high expression of SHN3 was associated with poor survival in GBM, showing a significant correlation with the classical and mesenchymal subtypes. In CRC, SHN3 expression showed a preferential association with the mesenchymal subtypes CMS4 and CRIS-B. Moreover, SHN3 expression strongly correlated with IL13Rα2 and MMP9-associated poor prognosis in different cancers. In conclusion, we have uncovered the participation of SNH3 in the IL-13/IL13Rα2/PTP1B pathway to promote tumor growth and invasion. These findings support a potential therapeutic value for SHN3.Angela Martín-Regalado was supported by an FPU fellowship (FPU18/05766-MEFP). Laura Pintado-Berninches was supported by a Margarita Salas contract (CA1/RSUE/2021-00208) from the Ministry of Universities (Spain). Javier Robles and Issam Boukich were supported by IND2019/BMD-17153 and IND2022/BMD-23554 fellow ships of the Comunidad de Madrid. This project was supported by grants RTI2018-095055-B-I00, PID2021-122227OB-I00 and CPP2021-008337 from the MCIN/AEI/10.13039/501100011033 using Next Generation EU/PRTR funds to JIC, and PI21CIII/00002 from the MCIN and FEDER funds to PSG and NINDS R01 NS122395 to IVB.S

    Fox : a un año de la alternancia

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    Reflexiones críticas desde diversas disciplinas de las ciencias sociales acerca del primer año de gobierno de Vicente Fox Quesada. Entre los rubros que se analizan están: la política cultural, el sector rural, los jóvenes, los derechos humanos, la cultura indígena y la seguridad pública.ITESO, A.C

    Group and call effect in achieving success in a subject: Analyses of the "Biology and Botany" whole life in the E.U.I.T.A. (University of Seville)

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    La Biología y la Botánica son dos materias fundamentales en la formación de un ingeniero técnico agrícola. Sus contenidos se han ofrecido a veces en asignaturas independientes y, en otras ocasiones como la que nos ocupa, en una sola asignatura. Por otra parte, siempre se ha mirado con interés, e incluso preocupación, el efecto de la variable grupo, de forma independiente o relacionándola con su distribución en turnos de mañana o tarde, así como la importancia de la convocatoria (en los distintos momentos a lo largo del curso académico) en la que el alumno consigue superar la asignatura. Aquí presentamos los resultados en la consecución de objetivos por parte de los alumnos y, por ende, de los profesores y de la Universidad de Sevilla a lo largo de la totalidad de la vida de la asignatura "Biología y Botánica" dentro del plan de estudios 2003/04 para tres titulaciones simultáneas, desde su comienzo en el curso 2003/04 hasta su extinción en el curso 2009/10, de la E.U.I.T.A. (Escuela Universitaria de Ingeniería Técnica Agrícola) de la Universidad de Sevilla. Además se consideran convocatorias pertenecientes al período de extinción añadido. Los análisis toman en cuenta además el éxito en la superación de la asignatura tanto de forma cualitativa (aprobado o suspenso de la evaluación a la que el alumno se ha sometido) como cuantitativa (nota conseguida). Las conclusiones obtenidas permiten mirar los resultados y la consecución de objetivos, así como una potencial toma de decisiones para el futuro, basándose en un marco temporal amplio y objetivo.Biology and Botany are two critical issues in the formation of a technical agricultural engineer. Their topics are sometimes offered in separate subjects and, at other times as here, within a single one. Besides, it has always been considered with interest, and even concern, the effect of the variable group, independently or in relation to their distribution in the morning or afternoon turns, and the importance of the call (at different times during the academic year) at which the student gets to pass the subject. Here we present the results in the achievement of objectives by students, and therefore teachers and the University of Seville, along the entire life of the subject "Biology and Botany" within the teaching 2003/04 plan for three simultaneous academic programs, from its start in the course 2003/04 to its extinction in the course 2009/10, in the E.U.I.T.A. (University School of Technical Agricultural Engineering) of the University of Seville. Calls belonging to the period of extinction are also considered. Analyses are both qualitative, based on having success in passing the subject or not, and quantitative (mark scored). Obtained conclusions let us see the results and the achievement of objectives, as well as a potential decision-making for the future, with a base on a comprehensive and objective frame

    Congenital leptin deficiency and leptin gene missense mutation found in two colombian sisters with severe obesity

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    Background: Congenital leptin deficiency is a recessive genetic disorder associated with severe early-onset obesity. It is caused by mutations in the leptin (LEP) gene, which encodes the protein product leptin. These mutations may cause nonsense-mediated mRNA decay, defective secretion or the phenomenon of biologically inactive leptin, but typically lead to an absence of circulating leptin, resulting in a rare type of monogenic extreme obesity with intense hyperphagia, and serious metabolic abnormalities. Methods: We present two severely obese sisters from Colombia, members of the same lineal consanguinity. Their serum leptin was measured by MicroELISA. DNA sequencing was performed on MiSeq equipment (Illumina) of a next-generation sequencing (NGS) panel involving genes related to severe obesity, including LEP. Results: Direct sequencing of the coding region of LEP gene in the sisters revealed a novel homozygous missense mutation in exon 3 [NM_002303.3], C350G>T [p.C117F]. Detailed information and clinical measurements of these sisters were also collected. Their serum leptin levels were undetectable despite their markedly elevated fat mass. Conclusions: The mutation of LEP, absence of detectable leptin, and the severe obesity found in these sisters provide the first evidence of monogenic leptin deficiency reported in the continents of North and South America. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

    COVID-19 infection in adult patients with hematological malignancies: a European Hematology Association Survey (EPICOVIDEHA)

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    Background: Patients with hematological malignancies (HM) are at high risk of mortality from SARS-CoV-2 disease 2019 (COVID-19). A better understanding of risk factors for adverse outcomes may improve clinical management in these patients. We therefore studied baseline characteristics of HM patients developing COVID-19 and analyzed predictors of mortality. Methods: The survey was supported by the Scientific Working Group Infection in Hematology of the European Hematology Association (EHA). Eligible for the analysis were adult patients with HM and laboratory-confirmed COVID-19 observed between March and December 2020. Results: The study sample includes 3801 cases, represented by lymphoproliferative (mainly non-Hodgkin lymphoma n = 1084, myeloma n = 684 and chronic lymphoid leukemia n = 474) and myeloproliferative malignancies (mainly acute myeloid leukemia n = 497 and myelodysplastic syndromes n = 279). Severe/critical COVID-19 was observed in 63.8% of patients (n = 2425). Overall, 2778 (73.1%) of the patients were hospitalized, 689 (18.1%) of whom were admitted to intensive care units (ICUs). Overall, 1185 patients (31.2%) died. The primary cause of death was COVID-19 in 688 patients (58.1%), HM in 173 patients (14.6%), and a combination of both COVID-19 and progressing HM in 155 patients (13.1%). Highest mortality was observed in acute myeloid leukemia (199/497, 40%) and myelodysplastic syndromes (118/279, 42.3%). The mortality rate significantly decreased between the first COVID-19 wave (March–May 2020) and the second wave (October–December 2020) (581/1427, 40.7% vs. 439/1773, 24.8%, p value < 0.0001). In the multivariable analysis, age, active malignancy, chronic cardiac disease, liver disease, renal impairment, smoking history, and ICU stay correlated with mortality. Acute myeloid leukemia was a higher mortality risk than lymphoproliferative diseases. Conclusions: This survey confirms that COVID-19 patients with HM are at high risk of lethal complications. However, improved COVID-19 prevention has reduced mortality despite an increase in the number of reported cases.EPICOVIDEHA has received funds from Optics COMMITTM (COVID-19 Unmet Medical Needs and Associated Research Extension) COVID-19 RFP program by GILEAD Science, United States (Project 2020-8223)

    Demographic History of Indigenous Populations in Mesoamerica Based on mtDNA Sequence Data

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    The genetic characterization of Native American groups provides insights into their history and demographic events. We sequenced the mitochondrial D-loop region (control region) of 520 samples from eight Mexican indigenous groups. In addition to an analysis of the genetic diversity, structure and genetic relationship between 28 Native American populations, we applied Bayesian skyline methodology for a deeper insight into the history of Mesoamerica. AMOVA tests applying cultural, linguistic and geographic criteria were performed. MDS plots showed a central cluster of Oaxaca and Maya populations, whereas those from the North and West were located on the periphery. Demographic reconstruction indicates higher values of the effective number of breeding females (Nef) in Central Mesoamerica during the Preclassic period, whereas this pattern moves toward the Classic period for groups in the North and West. Conversely, Nef minimum values are distributed either in the Lithic period (i.e. founder effects) or in recent periods (i.e. population declines). The Mesomerican regions showed differences in population fluctuation as indicated by the maximum Inter-Generational Rate (IGRmax): i) Center-South from the lithic period until the Preclassic; ii) West from the beginning of the Preclassic period until early Classic; iii) North characterized by a wide range of temporal variation from the Lithic to the Preclassic. Our findings are consistent with the genetic variations observed between central, South and Southeast Mesoamerica and the North-West region that are related to differences in genetic drift, structure, and temporal survival strategies (agriculture versus hunter-gathering, respectively). Interestingly, although the European contact had a major negative demographic impact, we detect a previous decline in Mesoamerica that had begun a few hundred years before

    The European Solar Telescope

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    The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes operating in visible and near-infrared wavelengths: the Swedish 1m Solar Telescope, the German Vacuum Tower Telescope and GREGOR, the French Télescope Héliographique pour l’Étude du Magnétisme et des Instabilités Solaires, and the Dutch Open Telescope. With its 4.2 m primary mirror and an open configuration, EST will become the most powerful European ground-based facility to study the Sun in the coming decades in the visible and near-infrared bands. EST uses the most innovative technological advances: the first adaptive secondary mirror ever used in a solar telescope, a complex multi-conjugate adaptive optics with deformable mirrors that form part of the optical design in a natural way, a polarimetrically compensated telescope design that eliminates the complex temporal variation and wavelength dependence of the telescope Mueller matrix, and an instrument suite containing several (etalon-based) tunable imaging spectropolarimeters and several integral field unit spectropolarimeters. This publication summarises some fundamental science questions that can be addressed with the telescope, together with a complete description of its major subsystems
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