Bibliometric analysis of scientific research on biochar

Objective: To identify the most relevant aspects of global scientific research on biochar in terms of the number of articles published, main authors and producer countries, citation, journal or journal topics, funding institutions and general trends. Design/ methodology/approach: A bibliometric research was carried out in the Scopus database. The word "biochar" was used as a search engine. The search was limited to articles and reviews published from 2009 to March 2020. The VOS viewer software was used to identify the main thematic axes and glimpse the knowledge gaps that exist to date. Results: A total of 11,444 documents were identified. The trend of work on biochar is on the rise. China and the United States are the countries with the most biochar publications. Jefferson Lehman and Stephen Josephs are the most cited authors on the subject. Global research in biochar focuses on the mitigating effect of climate change and the properties that this material has to improve the physicochemical properties of the soil. Research on biochar in Mexico is scarce. Limitations / implications: Biochar is a new technology that is not fully understood. Findings / Conclusions: Interest in biochar as a multifaceted solution to agricultural and environmental problems is growing at a rapid rate both domestically and internationally.Objective: To identify the most relevant aspects of global scientific research on biocharin terms of number of articles published, main authors and publishing countries, citation,subjects of scientific journals, funding institutions and general trends.Design/Methodology/Approach: A bibliometric study was carried out in the Scopusdatabase. The word "biochar" was used in the search engine. The search was limited to articles and reviews published from 2009 to March 2020. The VOS viewer software was used to identify the main thematic axes and to glimpse the knowledge gaps that exist to date.Results: A total of 11,444 documents were identified. The trend of work on biochar is onthe rise. China and the United States are the countries with the most publications onbiochar. Jefferson Lehman and Stephen Josephs are the most cited authors on thesubject. Global research on biochar focuses on the mitigating effect of climate changeand the properties that this material has to improve the physicochemical properties ofthe soil. Research on biochar in Mexico is scarce. Study Limitations/Implications: Biochar is a new technology that is not fullyunderstood.Findings/Conclusions: Interest in biochar as a multifaceted solution to agricultural andenvironmental problems is growing at a rapid rate both domestically and internationally

The labor market effects of technology shocks

We analyze the effects of neutral and investment-specific technology shocks on hours worked and unemployment. We characterize the response of unemployment in terms of job separation and job finding rates. We find that job separation rates mainly account for the impact response of unemployment while job finding rates for movements along its adjustment path. Neutral shocks increase unemployment and explain a substantial portion of unemployment and output volatilityinvestment-specific shocks expand employment and hours worked and mostly contribute to hours worked volatility. We show that this evidence is consistent with the view that neutral technological progress prompts Schumpeterian creative destruction, while investment specific technological progress has standard neoclassical feature

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Variaci?n intraespec?fica de rasgos funcionales de Cedrela odorata sobre un gradiente clim?tico en la Pen?nsula de Nicoya, Costa Rica

Tesis (Maestr?a) ? CATIE, Turrialba (Costa Rica), 2018Se conoce como variaci?n intraespec?fica a aquella diferenciaci?n fenot?pica dentro de una misma especie; es decir, individuos de la misma especie presentan caracter?sticas morfol?gicas o fisiol?gicas distintas. Recientes estudios sugieren que la variaci?n intraespec?fica de las especies puede influir en procesos ecol?gicos como el ensamblaje de comunidades. Estas investigaciones proponen que las especies presentan variaci?n en sus rasgos funcionales, para hacerlas m?s susceptibles de lograr superar los filtros ambientales del ecosistema. Al traspasar estos filtros, las especies con caracter?sticas similares coexisten y forman comunidades. Las caracter?sticas f?sicas, morfol?gicas y fisiol?gicas que influyen sobre el ?xito biol?gico de las especies, se conocen como rasgos funcionales. La ecolog?a funcional es la rama de la ecolog?a que se encarga de estudiar estos rasgos y trata de explicar c?mo a su vez tienen eco sobre el funcionamiento del ecosistema. La variaci?n en los rasgos, estar?a ligada a procesos de respuesta a las condiciones clim?ticas del entorno o a diferentes tipos y niveles de perturbaci?n. La manera m?s factible de comprobar estas ideas es mediante la investigaci?n en gradientes clim?ticos, ya que se pueden apreciar cambios en las condiciones ambientales en distancias relativamente cortas. Debido a lo anterior, se implement? un proyecto de investigaci?n para conocer si la especie Cedrela odorata, importante en los bosques secundarios de la pen?nsula de Nicoya, presentaba cierto grado de variaci?n intraespec?fica en sus rasgos funcionales, y si dicha variaci?n estaba relacionada a las condiciones clim?ticas de la zona de estudio. Para ello, se dividi? en tres ?reas clasificadas seg?n la cantidad de precipitaci?n media anual. El estrato 1 con un rango entre 1600-2400 mm, el estrato 2 entre 2400-2800 y el estrato 3 entre los 2800-4000 mm. Cada estrato coincide con las zonas de vida Holdridge: bosque seco tropical, bosque h?medo tropical y bosque muy h?medo tropical respectivamente. Se seleccionaron y evaluaron cinco rasgos funcionales (?rea foliar (mm2), contenido de materia seca foliar (mg/g), ?rea foliar espec?fica (mm2/mg), densidad de madera (g/cm3) y grosor de corteza (cm), con el prop?sito de conocer si exist?an diferencias entre las divisiones del gradiente y comprobar las hip?tesis planteadas. La hip?tesis central fue que la especie de estudio presentar?a caracter?sticas funcionales m?s adquisitivas en la zona h?meda y m?s conservativas en la zona seca, demostrando as? que C. odorata mostraba variaci?n intraespec?fica en sus rasgos. Cedrela odorata en la pen?nsula de Nicoya present? variabilidad en la media de los valores de sus rasgos, sin embargo, la hip?tesis sobre caracter?sticas conservativas y adquisitivas no se cumpli?. Solo el ?rea foliar parece responder positivamente al r?gimen de precipitaci?n, pues fue menor en el bosque seco tropical que en el bosque h?medo y muy h?medo tropical. Si bien C. odorata no cumpli? con las hip?tesis propuestas, esta especie arb?rea tropical si presenta cierto grado de variaci?n intraespec?fica en esta ?rea geogr?fica. Se aprecia que C. odorata obtuvo valores distintos en las medias de sus rasgos entre zonas del gradiente (p < 0,05), lo que sugiere la existencia de un proceso de ajuste como respuesta a los est?mulos externos, que no necesariamente es la cantidad de lluvia por a?o, el filtro ambiental con mayor efecto sobre la variaci?n en los valores de rasgos. La variaci?n intraespec?fica de los rasgos funcionales de Cedrela odorata podr?a ser el motor de la resiliencia de esta especie; sin embargo, hace falta mayor investigaci?n para tener certeza acerca de este proceso de adaptaci?n.CATIE (Centro Agron?mico Tropical de Investigaci?n y Ense?anza

Caso clínico:: Síndrome de Dravet

INTRODUCCIÓN. El Síndrome de Dravet es la forma más grave de un espectro de epi-lepsias relacionadas con el gen SCN1A, y se caracteriza por ser una epi-lepsia refractaria de inicio precoz. CASO CLÍNICO Paciente con embarazo y parto normales. Presenta la primera crisis alos 3 meses y medio, hemiconvulsión afebril izquierda. La segunda ocu-rrió a las 24 horas.A lo largo de la evolución de su enfermedad ha presentado distin-tos tipos de crisis: primero hemiconvulsiones afebriles/febriles, con fre-cuente generalización posterior. Posteriormente aparecen crisis miocló-nicas, orofaciales y de extremidades. En los últimos años coinciden conla primera y última fase del sueño.Ha presentado hasta 20 crisis al día y tres estatus (el primero al añode vida). Se objetivó comienzo de retraso psicomotor a los 2 años ymedio, junto a rasgos de trastorno del espectro autista.Ha recibido tratamiento con 13 tipos de fármacos antiepilépticos,junto a dieta cetogénica.Las exploraciones complementarias realizadas son normales o conalteraciones inespecíficas. En mayo de 2009 se recibe genética positiva.Actualmente tiene 12 años, y el número de crisis es variable. Está eneducación especial, en la exploración neurológica destaca torpeza motora. COMENTARIOS La causa más frecuente del Síndrome de Dravet es la alteración en la subu-nidad α1 del canal de sodio SCN1A neuronal (de novo). Existen otrosgenes implicados.Las crisis aparecen en el primer año de vida, generalmente con fiebre,generalizadas o unilaterales, que pueden ser prolongadas. Con el tiempo,aumentan en frecuencia, sin fiebre y aparecen otros tipos de crisis.El desarrollo es normal hasta el inicio de la enfermedad, pero poste-riormente se observan diversos grados de retraso. Con el aumento de lafrecuencia y la gravedad de las crisis pueden aparecer otras alteraciones(motoras, lenguaje, comportamiento...).Algunos fármacos son beneficiosos para el control de las crisis, perootros son claramente contraproducentes (Lamotrigina, Fenitoína, Carba-mazepina, Oxcarbazepina,Vigabatrina)

Facial Nerve Regeneration through Progesterone-Loaded Chitosan Prosthesis. A Preliminary Report

Biodegradable nerve guides have represented new treatment alternatives for nerve repairing. They are gradually biodegradable, exert biological effects directly to the injured nerve, and act as drug- or cell-delivery devices. Furthermore, progesterone (PROG) has been demonstrated to promote injured peripheral nerve regeneration. In this study, it was hypothesized that PROG delivered from chitosan prostheses provides better facial nerve regenerative response than chitosan prostheses with no PROG. As there are no reports on the use of the former as nerve-guide material in the regeneration of injured nerves, this is the main objective of the present work. Chitosan prostheses containing PROG were used to bridge 10-mm gaps in rabbit facial nerves. The regenerated nerves were evaluated 45 days after implantation in animals with the use of light microscopy and morphometric analysis. Gas chromatography was used in order to quantify PROG content in prosthesis prior to and after implantation in subcutaneous tissue at different periods of up to 60 days. In addition, the prosthesis walls were evaluated with histological techniques in order to assess their integrity and the surrounding tissue reaction. Chitosan prostheses allowed PROG release during the time needed for nerve regeneration. At 45 days myelinated nerve fibers were observed in both the proximal and distal stumps. This parameter and the N ratio were higher in the progesterone-treated group when compared to that of the vehicle control. Findings indicate that chitosan prostheses were useful in nerve regeneration, acting as a long-lasting PROG delivery device a faster nerve regeneration. © 2003 Wiley Periodicals, Inc.Peer Reviewe