Caracterización de aislamientos de Ralstonia Solanacearum Raza 2, agente causal de Moko de plátano, en el Valle del Cauca, Colombia = Characterizing Strains of Ralstonia Solanacearum Race 2, Causal Agent of Moko of Plantain, In Valle Del Cauca, Colombia

Moko is a bacterial wilt of plantain and banana, caused by Ralstonia solanacearum race 2. It is the most important disease of these crops in Colombia, affecting 125,000 families. R. solanacearum has a wide range of hosts, geographical distribution, and pathogenicity. This study aimed to isolate R. solanacearum from infected plant tissue, using SMSA medium, real-time PCR with specific TaqMan probe Mus 20P and primers Mus 20F and Mus 20RP, and duplex PCR. We then evaluated the strains pathogenicity levels. A total of 93 samples of infected plant tissue from pseudostems, rachis, and petioles of selected plantain and banana plants were obtained in Valle del Cauca. Samples were amplified with duplex PCR and real-time PCR, with specific TaqMan probe Mus 20P and specific primers Mus 20F and Mus 20RP. The strains, identified by PCR as R. solanacearum, were inoculated into plantain plants of Dominico Hartón (Musa cv. AAB). As the positive check, the pathogenic strain R. solanacearum CIAT 078 was used. An analysis of variance was carried out for the variable AUDPC with minimum significant difference (MSD; = 5%) to separate the strains into three groups of pathogenicity. Seventy-five strains were positive for real-time PCR with Ct value 25, which corresponded to the pathogen Ralstonia solanacearum. For 61 of the 75 strains obtained, the fragment was located in a gene related to chemotaxis protein, which is used to identify the strains as R. solanacearum phylotype II, measuring 500 bp, which was amplified with primers 93F/93R and 5F/5R

El Management como práctica: una aproximación a la naturaleza del trabajo directivo

En el presente trabajo se realiza una reflexión sobre la naturaleza del trabajo directivo –management–, a la luz de los tres modos posibles de conocimiento: la teoría, la práctica y la técnica. Puntualmente, se analiza el trabajo de tres autores: Henry Mintzberg, Ikujiro Nonaka y Alasdair MacIntyre, con el fin de mostrar cómo la evolución del estudio teórico de esta disciplina ha ido evidenciando su carácter eminentemente práctico. Mintzberg aporta una excelente introducción al fenómeno, ya que combina muy bien la observación práctica con la reflexión sobre lo que hacen los realmente directivos. Nonaka, por su parte, resalta el dinamismo de la empresa: su capacidad de innovar, de crear y compartir conocimiento. Finalmente, MacIntyre reivindica la perspectiva aristotélica en el estudio de la vida organizacional, con su revitalización de la noción de práctica. Se concluye resaltando que concebir el trabajo directivo como una práctica abre paso a una teoría normativa de la acción y su influencia en las organizaciones.This article reflects on the nature of managerial work, which historically has been approached as a theory, a practice, or a technique. The work of three authors, Henry Mintzberg, Ikujiro Nonaka and Alasdair MacIntyre, is analyzed in order to show how the evolution of this discipline’s theoretical study demonstrates its eminently practical nature. Mintzberg provides an excellent introduction to the phenomenon, perceptively combining practical observation with reflection on what managers actually do. Nonaka, on the other hand, highlights the dynamism of the business firm and its ability to innovate, create and share knowledge. Finally, MacIntyre revives the Aristotelian perspective in the study of organizational life, revitalizing the idea of practice. We conclude by emphasizing that conceiving of managerial work as a practice implies the acceptance of a normative theory of organizations

Evaluation of the Uncertainty of Surface Temperature Measurements in Photovoltaic Modules in Outdoor Operation

Faults in photovoltaic modules in operation can lead to power losses. By determining the module surface temperature, hot spots that can potentially cause this power loss can be detected. Temperature measurement by radiation allows a complete, reliable, and fast qualitative determination of hot spots on PV modules in outdoor operation. However, to obtain quantitative values, it is necessary to consider multiple factors: emissivity, reflected radiation, wind speed, intensity, shading, etc. Temperature quantitative measurement evaluation by contact is more studied, although by this technique it is impossible to examine the temperature of the entire module to detect hot spots because it is a point measurement and due to shading caused by the measurement probe on the surface. In this work, a method of temperature measurement by radiation is described, evaluating the uncertainty components, and a comparison is made with temperature measurement by contact on the module rear side points where module heating has been detected, also evaluating the uncertainty components. This comparison of both methods and uncertainty determination allows establishing a methodology in quantitative temperature measurement by radiation in photovoltaic modules in outdoor operation

Uncertainty Assessment in Temperature Uniformity Survey of Thermal Processing Equipment According to AMS2750 Aerospace Specification

Thermal processing equipment used in the aerospace industry must meet the requirements of the processes for which they are intended. The periodic tests performed by calibration laboratories, according to the AMS2750 specification, are intended to ensure compliance with these equipment requirements. While this specification does not explicitly state the need for uncertainty calculation, it does specify that pyrometry laboratories must have an ISO/IEC 17025 Quality System accredited by a recognized regional body which is a member of the International Laboratory Accreditation Cooperation (ILAC). Therefore, the calculation of uncertainties is necessary. This work presents a methodology for conducting temperature uniformity surveys and uncertainty assessment in these tests. This methodology has been applied to four different types of equipment to analyse, in each case, the contributions of uncertainties and to assess their potential for improvement. The objectives that laboratories should aim for include improving measurement accuracy and reducing uncertainty components in order to meet the criteria of both AMS2750 and ISO/IEC 17025

Strategy Based on Two Stages for IR Thermographic Inspections of Photovoltaic Plants

Aerial infrared (IR) thermography has been implemented in recent years, proving to be a powerful and versatile technique for performing maintenance at photovoltaic (PV) plants. Its application speed and reliability using unmanned aerial vehicles (UAVs) or drones make it extremely interesting at large PV plants, due to the associated savings in time and costs. Ground-level thermographic inspection is slower and more costly to apply, although it does provide higher optical resolution, due to being conducted closer to the PV modules being inspected. Both techniques used in combination can improve the diagnosis. An IR thermography inspection strategy is proposed for PV plants based on two stages. The first stage of the inspection is aerial, enabling thermal faults to be detected and located quickly and reliably. The second stage of the inspection is done on the ground and applied only to the most relevant incidents revealed in the first stage. This inspection strategy was applied to a 100 kW PV plant, with an improved diagnosis verified via this procedure, as the ground-level inspection detects one-off thermal incidents from objects creating shade and from solar reflections. For PV modules with open circuits or open substrings, the use of one technique or another is immaterial

Expresión de la autoestima del ser humano

Concebir la creatividad como la facultad que posee el hombre para pensar de manera diferente de los demás y de sí mismo, es apasionante y seductor; pero concebirla además de ello como una habilidad que no sólo haya su soporte fisiológico en el cerebro humano, sino que se fundamenta también en la autoestima de la persona, lo hace todavía más apasionante y sobre todo más humanizante, constructivo y edificante