Smearing of causality by compositeness divides dispersive approaches into exact ones and precision-limited ones

Scattering off the edge of a composite particle or finite-range interaction can precede that off its center. An effective theory treatment with pointlike particles and contact interactions must find that the scattered experimental wave is slightly advanced, in violation of causality (the fundamental underlying theory being causal). In practice, partialwave or other projections of multivariate amplitudes exponentially grow with Im(E), so that analyticity is not sufficient to obtain a dispersion relation for them, but only for a slightly modified function (the modified relations additionally connect different J). This can limit the precision of certain dispersive approaches to compositeness based on Cauchy's theorem. Awareness of this may be of interest to some dispersive tests of the Standard Model with hadrons, and to unitarization methods used to extend electroweak effective theories. Interestingly, the Inverse Amplitude Method is safe (as the inverse amplitude has the opposite, convergent behavior allowing contour closure). Generically, one-dimensional sum rules such as for the photon vacuum polarization, form factors or the Adler function are not affected by this uncertainty; nor are fixed-t dispersion relations, cleverly constructed to avoid it and whose consequences are solid

Growth Promoting Rhizobacterium Effects on Coffea arabiga Scion onto Robusta Rootstock

Context: No reports about the response of the main Coffea arabica L. genotypes grafted onto Coffea canephora in the presence of plant growth promoting rhizobium have been found yet. Aim: To evaluate the effect of Rhizobium alamii Rpr2 on C. arabica L. development while grafted onto C. canephora (Robusta). Methods: The trial was conducted under a randomized block design, with a 4x2 factorial arrangement, in four replicas. The factors were four C. arabica L. genotypes. (Isla 6-14, Isla 5-15, Isla 6-11, and San Ramón), and two rhizobium application levels (with rhizobium or without it). The days to inosculation were evaluated, along with the percentage of graft inosculation, graft height, graft stem height, number of graft leaf pairs, foliar area, dry leaf mass, root growth, root volume, and root dry mass. Results: The results showed the interaction between the grafted C. arabica species, and strain R. alamii Rpr2. The inoculated scion Isla 6-14/Robusta showed a better response than the other treatments and the control, which makes it a suitable variant for coffee growing. Conclusions: The utilization of plant-growth promoting bacteria is an effective alternative for grafting stimulation and development, which might lead to greater availability of plantlets ready for large-scale planting in the field

Simulación e implementación de proceso de Pick and Place colaborativo con dos robots industriales

In recent times, a fraction of industrial robotics has been oriented to a collaborative approach between different devices to achieve a specific task. This paper describes the simulation and deployment of a metallic beam pick a place process using tow industrial robots. At first, the tool design is presented; it used an electromagnet attached to the robot end effector to lift the load correctly. The communication sequence between the robot's controllers using the digital I/O modules is discussed. The software Robot Studio allowed the process simulation, in which the performance was validated. All the tasks were tested in two ABB IRB 140 industrial robots.En los últimos años la robótica industrial se ha orientado hacia la coordinación entre diferentes manipuladores para realizar una determinada labor. En este sentido, el presente documento expone la simulación e implementación de un proceso Pick and Place de una viga metálica haciendo uso de dos robots industriales. Para tal fin, se diseñó una herramienta de electroimán para levantar apropiadamente la carga. Además, se elaboró una secuencia de comunicación entre los dos robots haciendo uso de los módulos de I/O digitales de los controladores, para así sincronizar el movimiento de los robots de manera sencilla. Finalmente, se implementó el proceso y se verificó el funcionamiento correcto de todos los sistemas descritos anteriormente

Rizobacteria promotora del crecimiento favorece el desarrollo de Coffea arabiga L. injertadas sobre patrón robusta

Contexto: En el Cuba aún no se ha informado la respuesta de los principales genotipos de Coffea arabica L. injertados sobre Coffea canephora en presencia de cepa de rizobio promotora del crecimiento vegetal. Objetivo: Evaluar el efecto de Rhizobium alamii Rpr2, en el desarrollo de C. arabica L., injertadas de forma individual sobre el patrón C. canephora (Robusta). Métodos: El ensayo se condujo bajo un diseño de bloques al azar en arreglo factorial 4x2, con cuatro réplicas.  Los factores fueron cuatro genotipos de C. arabica L. (Isla 6-14, Isla 5-15, Isla 6-11 y San Ramón) y dos niveles de aplicación de rizobio (con y sin aplicación). Se evaluó los días al prendimiento, porcentaje de prendimiento del injerto, altura del injerto, diámetro del tallo del injerto, número de pares hojas del injerto, área foliar, masa seca foliar, crecimiento de la raíz, volumen de la raíz y masa seca de la raíz. Resultados: Los resultados mostraron la interacción que existe entre el tipo de la especie C. arabica injertada y la cepa R. alamii Rpr2. El injerto Isla 6-14/Robusta inoculado se mostró superior con respecto a los demás tratamientos y controles, lo cual lo convierte en una variante a emplear en la caficultura. Conclusiones: El uso de bacterias promotoras do crecimiento vegetal es una alternativa eficaz en la estimulación y desarrollo de injertos que puede redundar en una mayor disponibilidad de posturas aptas para ampliar el volumen de café a ser establecido en condiciones de campo

Aplicación de Nanomateriales en la Agricultura

In recent years, the use of nanomaterials in various areas of science and engineering has increased considerably. In agriculture it is not the exception, due to the need to look for new alternatives to traditional fungicides for the development of corn grains and other cereals. In this work, a study of the cytotoxicity of a material composed of chitosan-carbon nanotubes (CNT) applied to the fungus Aspergillus parasiticus as support in agriculture and food preservation was carried out. The cytotoxicity of the composite material was determined through the experimental technique of optical microscopy by evaluating the number of germinated spores where the inhibition of hyphal growth in the culture of the Aspergillus parasiticus fungus was evidenced. Transmission electron microscopy (TEM) was used, where it was found that the carbon nanotubes are immersed in the chitosan polymer matrix and the presence of chitosan nanoaggregates of 50 nm in diameter was observed, which in turn are located as a coating on the surface of the CNTs. This work is evidence that the use of nanomaterials presents a good tool in the fight against pathogens in agriculture.En los últimos años el uso de los nanomateriales en diversas áreas de ciencia e ingeniería va aumentado consideradamente. En la agricultura no es la excepción, debido a la necesidad de buscar nuevas alternativas a los fungicidas tradicionales para el desarrollo de los granos de maíz y otros cereales. En este trabajo se llevó a cabo un estudio de la citotoxicidad de un material compuesto por quitosano-nanotubos de carbono (CNT) aplicados al hongo Aspergillus parasiticus como apoyo en la agricultura y conservación de alimentos. Se determinó la citotoxicidad del material compuesto mediante la técnica experimental de microscopia óptica al evaluar el número de esporas germinadas donde se evidenció la inhibición del crecimiento de hifas en el cultivo del hongo Aspergillus parasiticus. Se utilizó la microscopía electrónica de transmisión (TEM) donde se encontró que los nanotubos de carbono se encuentran inmersos en la matriz polimérica del quitosano y se observó la presencia de nanoagregados de quitosano de 50 nm de diámetro que se localizan a su vez a modo de recubrimiento sobre la superficie de los CNT. Este trabajo es una evidencia de que el uso de nanomateriales presenta una buena herramienta en el combate de agentes patógenos en la agricultura

La modernización del campo y la globalización económica

El presente libro incluye las ponencias presentadas en el del XIV Seminario de Economía Agrícola del Tercer Mundo, en el cual participan distinguidos especialistas nacionales y extranjeros, atentos a la dinámica y a la problemática actual de la producción primaria y el desarrollo rural de México y el mundo. El interés se centró en la elaboración de análisis críticos y propositivos en torno a los cambios ocurridos durante los últimos años en el sector rural mexicano a la luz del proceso de modernización y globalización económica en que está inmerso nuestro país. Los trabajos presentados en el Seminario muestran un consenso básico en torno a la importancia estratégica del sector agropecuario y rural para la construcción de un proyecto de desarrollo nacional sostenido, equilibrado y democrático

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

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