Effect of Cultivar on Chlorophyll Meter and Canopy Reflectance Measurements in Cucumber

Optical sensors can be used to assess crop N status to assist with N fertilizer management. Differences between cultivars may affect optical sensor measurement. Cultivar effects on measurements made with the SPAD-502 (Soil Plant Analysis Development) meter and the MC-100 (Chlorophyll Concentration Meter), and of several vegetation indices measured with the Crop Circle ACS470 canopy reflectance sensor, were assessed. A cucumber (Cucumis sativus L.) crop was grown in a greenhouse, with three cultivars. Each cultivar received three N treatments, of increasing N concentration, being deficient (N1), sufficient (N2) and excessive (N3). There were significant differences between cultivars in the measurements made with both chlorophyll meters, particularly when N supply was sufficient and excessive (N2 and N3 treatments, respectively). There were no consistent differences between cultivars in vegetation indices. Optical sensor measurements were strongly linearly related to leaf N content in each of the three cultivars. The lack of a consistent effect of cultivar on the relationship with leaf N content suggests that a unique equation to estimate leaf N content from vegetation indices can be applied to all three cultivars. Results of chlorophyll meter measurements suggest that care should be taken when using sufficiency values, determined for a particular cultiva

The Use of Chlorophyll Meters to Assess Crop N Status and Derivation of Sufficiency Values for Sweet Pepper

Chlorophyll meters are promising tools for improving the nitrogen (N) management of vegetable crops. To facilitate on-farm use of these meters, sufficiency values that identify deficient and sufficient crop N status are required. This work evaluated the ability of three chlorophyll meters (SPAD-502, atLEAF+, and MC-100) to assess crop N status in sweet pepper. It also determined sufficiency values for optimal N nutrition for each meter for pepper. The experimental work was conducted in a greenhouse, in Almería, Spain, very similar to those used for commercial production, in three different crops grown with fertigation. In each crop, there were five treatments of different N concentration in the nutrient solution, applied in each irrigation, ranging from a very deficient to very excessive N supply. In general, chlorophyll meter measurements were strongly related to crop N status in all phenological stages of the three crops, indicating that these measurements are good indicators of the crop N status of pepper. Sufficiency values determined for each meter for the four major phenological stages were consistent between the three crops. This demonstrated the potential for using these meters with sufficiency values to improve the N management of commercial sweet pepper crops

Creativity training programs in primary education: A systematic review and meta-analysis

The aim of the systematic review was to examine the effectiveness of creativity training programs, interventions, or practices on creativity or divergent thinking in typical developing primary education pupils. A systematic review protocol was designed and implemented, and a systematic literature search was conducted across diverse electronic platforms and databases, as well as other resources. The final sample of high methodological quality studies reviewed was 6. A narrative content analysis approach was adopted, and a random effects analysis with restricted maximum likelihood was used to conduct the meta-analysis. The meta-analytic estimate of the overall effect size of the combined studies shows moderate effect across all studies. The results suggest that some programs, interventions, or practices exist that can effectively help teachers, practitioners, and policy makers to promote creativity or divergent thinking in school-aged children

Information in feedback ratchets

Feedback control uses the state information of the system to actuate on it. The information used implies an effective entropy reduction of the controlled system, potentially increasing its performance. How to compute this entropy reduction has been formally shown for a general system, and has been explicitly computed for spatially discrete systems. Here, we address a relevant example of how to compute the entropy reduction by information in a spatially continuous feedback-controlled system. Specifically, we consider a feedback flashing ratchet, which constitutes a paradigmatic example for the role of information and feedback in the dynamics and thermodynamics of transport induced by the rectification of Brownian motion. A Brownian particle moves in a periodic potential that is switched on and off by a controller, with the latter performing the switching depending on the system state. We show how the entropy reduction can be computed from the entropy of a sequence of control actions, and also discuss the required sampling effort for its accurate computation. Moreover, the output power developed by the particle against an external force is investigated, which -- for some values of the system parameters -- is shown to become larger than the input power due to the switching of the potential: the apparent efficiency of the ratchet thus becomes higher than one, if the entropy reduction contribution is not considered. This result highlights the relevance of including the entropy reduction by information in the thermodynamic balance of feedback controlled devices, specifically when writing the second principle: the inclusion of the entropy reduction by information leads to a well-behaved efficiency over all the range of parameters investigated.Comment: 17 pages, 13 figure

MODELO LIGERO PARA LA EVALUACIÓN DE PROCESOS SOFTWARE

 RESUMENLa mejora en los procesos de desarrollo de software garantiza a las empresas, alcanzar altos niveles de madurez en los procesos e incrementa la competitividad internacional. Es necesario adecuar los modelos de mejora, evaluación y calidad que son reconocidos internacionalmente, a las características propias de los países donde son aplicados. Estos modelos difícilmente pueden ser aplicados en la mayoría de las empresas de muchos países iberoamericanos debido a la gran inversión en dinero, tiempo y recursos que requieren, así como a la complejidad de las recomendaciones que proporcionan y a un retorno de la inversión a largo plazo. Especialmente, las pequeñas empresas que inicien una cultura de mejora continua tienen la necesidad de realizar una evaluación respecto a un modelo de calidad. El primer paso en el proceso de mejora es determinar el estado en el que se encuentran sus procesos software. El proceso de evaluación permite conocer las fortalezas y debilidades que guían un programa de mejora de procesos al interior de la organización. El objetivo de este articulo es presentar MECPDS, un modelo ligero de evaluación de la calidad de procesos de desarrollo de software basado las normas ISO/IEC 12207:2002 e ISO/IEC 15504:2003 aplicable a las micro, pequeñas y medianas empresas, de manera fácil y económica, con pocos recursos y en poco tiempo.   PALABRAS CLAVESModelos de EvaluaciónFramework de MedidaModelos de Proceso de ReferenciaCapacidad del ProcesoCumplimiento del ProcesoISO/IEC 12207:2002ISO/IEC 15504:2003.  ABSTRACTThe Software Process Improvement guarantees to organizations, to reach high maturity levels in processes and increases international competitiveness. It is necessary to adapt the Improvement, Evaluation and Quality Models that are recognized internationally, to the own characteristics of countries where they are applied. These models hardly can be applied in the companies of many Latin American countries due to the great investment in money, time and resources that they require, as well as the complexity of the recommendations that they provide and a return of the investment in the long term. Specially, small organizations that initiate a culture of continuous improvement have the necessity to make an evaluation with respect to a Quality Model. The first step in the improvement process is to determine the current state of their software processes. The evaluation process allows us to know the strengths and weaknesses that guide a processes improvement program within an organization. The goal of this paper is to present MECPDS, a light model of evaluation of the quality of software development processes based on norms ISO/IEC 12207:2002 and ISO/IEC 15504:2003 applicable to micro, small and medium organizations, of easy and economic way, with investment of few resources and time. KEYWORDSEvaluation ModelsMeasurement FrameworkProcess Reference ModelsProcess CapabilityFulfillment of ProcessISO/IEC 12207:2002ISO/IEC 15504:2003

Global trends in nitrate leaching research in the 1960–2017 period

Nitrate leaching is the process whereby the nitrate (NO3−) anion moves downwards in the soil profile with soil water. Nitrate leaching is commonly associated with chemical nitrogen (N) fertilizers used in agriculture. Nitrate leaching from different sources and contamination of surface and groundwater is a global phenomenon that has prompted social and political pressure to reduce nitrate leaching and contamination of water bodies. This bibliometric study analyzed global trends in nitrate leaching research. The results showed a rising interest in the last decades in this topic; given the growth tendency over the last years, it was envisaged that the importance on nitrate leaching research will continue increasing in the future. Knowledge on nitrate leaching was mostly disseminated through scientific publications (90% of total documents recovered), both as journal articles and reviews, classified in the Scopus database in the Agricultural, Biological and Environmental Sciences areas. Most publications dealt with soil nitrogen losses from agroecosystems and farmlands and the associated impact on the environment; they were published in journals with a focus on the influence of anthropogenic and soil-crop-animal systems in the environment, and on how such changes in the environment impact agroecosystems. Most documents published on nitrate leaching were indisputably from the United States, followed by China, the United Kingdom and Germany. An analysis of the main keywords showed an overall dominance of the soil nitrogen cycle, fertilizer use in agriculture and water quality aspects. The evolution of main crop species involved in nitrate leaching research showed a rising relevance of research conducted with maize, wheat and grasses from 1990 onwards. The most productive institutions in terms of number of documents dealing with nitrate leaching research, h-index and total citations, were located in the United States, China and the Netherlands. The United States Department of Agriculture stood out, followed by the Chinese Academy of Sciences and Wageningen University and Research. There were clusters of institutions with intercontinental interaction, on nitrate leaching research, between institutions from Europe, Asia and South and North America. Overall, this study has highlighted, from a bibliometric perspective, the rising concern on nitrate leaching. Progress in this field has been made particularly on the impact of the soil-plant-animal system on the environment and agroecosystems, and on fundamental and applied aspects of plant-soil interactions with an emphasis in cropping systems

Distinct expression patterns predict differential roles of the miRNA-binding proteins, Lin28 and Lin28b, in the mouse testis: studies during postnatal development and in a model of hypogonadotropic hypogonadism

[Abstract] Lin28 (also termed Lin28a) and Lin28b are related RNA-binding proteins, involved in the control of microRNA synthesis, especially of the let-7 family, with putative functions in early (embryo) development. However, their roles during postnatal maturation remain ill defined. Despite the general assumption that Lin28 and Lin28b share similar targets and functions, conclusive demonstration of such redundancy is still missing. In addition, recent observations suggest a role of Lin28 proteins in mammalian reproduction, which is yet to be defined. We document herein the patterns of RNA expression and protein distribution of Lin28 and Lin28b in mouse testis during postnatal development and in a model of hypogonadotropic hypogonadism as a result of inactivation of the kisspeptin receptor, Gpr54. Lin28 and Lin28b mRNAs were expressed in mouse testis across postnatal maturation, but their levels disparately varied between neonatal and pubertal periods, with peak Lin28 levels in infantile testes and sustained elevation of Lin28b mRNA in young adult male gonads, where relative levels of let-7a and let-7b miRNAs were significantly suppressed. In addition, Lin28 peptides displayed totally different patterns of cellular distribution in mouse testis: Lin28 was located in undifferentiated and type-A1 spermatogonia, whereas Lin28b was confined to spermatids and interstitial Leydig cells. These profiles were perturbed in Gpr54 null mouse testis, which showed preserved but irregular Lin28 signal and absence of Lin28b peptide, which was rescued by administration of gonadotropins, mainly hCG (as super-agonist of LH). In addition, increased relative levels of Lin28, but not Lin28b, mRNA and of let-7a/let-7b miRNAs were observed in Gpr54 KO mouse testes. Altogether, our data are the first to document the divergent patterns of cellular distribution and mRNA expression of Lin28 and Lin28b in the mouse testis along postnatal maturation and their alteration in a model of congenital hypogonadotropic hypogonadism. Our findings suggest distinct functional roles of these two related, but not overlapping, miRNA-binding proteins in the male gonad.Ministerio de Ciencia e Innovación; BFU 2008-00984Ministerio de Ciencia e Innovación; BFU2011-25021Junta de Andalucía; Project P08-CVI-03788European Commission; DEER FP7-ENV-2007-

Testicular expression of the Lin28/let-7 system: hormonal regulation and changes during postnatal maturation and after manipulations of puberty

[Abstract] The Lin28/let-7 system, which includes the RNA-binding proteins, Lin28a/Lin28b, and let-7 miRNAs, has emerged as putative regulator of puberty and male gametogenesis; yet, its expression pattern and regulation in postnatal testis remain ill defined. We report herein expression profiles of Lin28 and let-7 members, and related mir-145 and mir-132, in rat testis during postnatal maturation and in models of altered puberty and hormonal deregulation. Neonatal expression of Lin28a and Lin28b was low and rose markedly during the infantile period; yet, expression patterns diverged thereafter, with persistently elevated levels only for Lin28b, which peaked at puberty. Let-7a, let-7b, mir-132 and mir-145 showed profiles opposite to Lin28b. In fact, let-7b and mir-145 were abundant in pachytene spermatocytes, but absent in elongating spermatids, where high expression of Lin28b was previously reported. Perturbation of puberty by neonatal estrogenization reverted the Lin28/let-7 expression ratio; expression changes were also detected in other models of delayed puberty, due to early photoperiod or nutritional manipulations. In addition, hypophysectomy or growth hormone (GH) deficiency revealed regulation of this system by gonadotropins and GH. Our data document the expression profiles of the Lin28/let-7 system in rat testis along postnatal/pubertal maturation, and their perturbation in models of pubertal and hormonal manipulation.Ministerio de Economía y Competitividad; BFU2011-025021Ministerio de Economía y Competitividad; BFU2014-57581Junta de Andalucía; P08-CVI-03788Junta de Andalucía; P12-FQM-01943Xunta de Galicia; EM2013/01

Improving oral presentation skills for radiology residents through clinical session meetings in the virtual world Second Life

Background: The objective of this study was to conduct a clinical session meeting in the virtual world of Second Life to improve the oral presentation skills of radiology residents and to assess the perception of the attendees. Methods: A clinical session meeting (10 two-hour sessions over four weeks), where participants presented their own clinical sessions, followed by a turn of interventions by the attendees, was designed and carried out. Attendees were asked to complete an evaluation questionnaire. Descriptive statistics were performed. Results: Twenty-eight radiology residents attended the meeting, and 23 (81.2%) completed the evaluation questionnaire; 95.7–100% of them agreed that the virtual environment was attractive and suitable for holding the meeting and that the content was appropriate for their training as residents. They rated with ≥8.9 points (from 1 to 10) different aspects of the experience, highlighting the role of teachers (9.7 ± 0.6) and the usefulness of their training (9.4 ± 0.9). Conclusions: Second Life can be used effectively to train oral communication skills in public, in an environment perceived as attractive and suitable for learning, through an experience described by the attendees as interesting and useful, highlighting the advantages of social contact with their peersWe want to acknowledge the Asociación de Radiólogos del Sur, a subsidiary of SERAM, for its contribution to the maintenance costs of the Medical Master Island during the development of this project. Partial funding for open access charge: Universidad de Málag