Light-harvesting in bacteria exploits a critical interplay between transport and trapping dynamics

Light-harvesting bacteria Rhodospirillum Photometricum were recently found to adopt strikingly different architectures depending on illumination conditions. We present analytic and numerical calculations which explain this observation by quantifying a dynamical interplay between excitation transfer kinetics and reaction center cycling. High light-intensity membranes (HLIM) exploit dissipation as a photo-protective mechanism, thereby safeguarding a steady supply of chemical energy, while low light-intensity membranes (LLIM) efficiently process unused illumination intensity by channelling it to open reaction centers. More generally, our analysis elucidates and quantifies the trade-offs in natural network design for solar energy conversion.Comment: 4 pages and 4 figures. Accepted for publication in Physical Review Letters

Innovation in the value chain of wood products: data, equations and life-cycle analysis

This chapter represents a review of the state of the art of the techniques and methodologies described and used in Lizarralde et af., 2008. Several issues have been reviewed and updated, while the work area and most of data remain equal,as an exercise of methodology review. Assessment of C02 sequestration on wood products starts to raise importance when measuring the global sequestration in a forest. In this work, a more accurate estimation of C0.2 on wood products is proposed,taking into account not only the volume but the useful life of those products. In order to estímate this carbon uptake and sequestration, innovation in forestry reveals new technologies and methodologies such as forest inventory using LiDAR technology or advanced modelling techniques. Besides,a new accountability and legal framework is added to review the state of the art of this particular issue. With this new information and knowing yield data of transformation of these products in final commercial products, the sequestration rate of each product and its useful life, we will be able to calculate the global sequestration of annual cuttings in an important and well-known forest in Spain.Instituto Universitario de Gestión Forestal Sostenibl

A web-based application to simulate alternatives for sustainable forest management: SIMANFOR

Producción CientíficaGrowth and yield models at different scales are useful tools for forest stakeholders. Adequate simulation of forest stand conditions after different silvicultural scenarios allows stakeholders to adopt appropriate actions to maintain forest integrity while forest products and services are obtained to benefit society as a whole. SIMANFOR is a platform to simulate sustainable forest management alternatives, integrating different modules to manage forest inventories, simulate and project stand conditions and maintain systems security and integrity. SIMANFOR output is compatible with an Office environment (Microsoft or Open), allowing users to exchange data and files between SIMANFOR and their own software. New developments are being planned under a web 2.0 environment to take advantage of user input to improve SIMANFOR in the future

Valoración de salud mental en formación de profesores en dos universidades chilenas

This study analyzed the evaluation of professors of pedagogy and directors programs, about the importance of mental health in vocational training, and factors that might influence this valuation. The methodology includes participation of 17 academicians (professors and belonging to the managerial staff) of two universities in southern Chile. A survey with closed and open questions, and in-depth interviews were used to collect information. Data was analyzed using content analysis. The results show that teachers have, mostly, a high personal assessment of the topic ( = 2.8, between 0 and 3). There is, on the other hand, an ambivalent valuation on the part of the institutions; a lack of knowledge and a low conceptual and procedural proficiency of pedagogues, and a low priority as a competence in their training (59% of participants are not aware of the existence of any programs or courses related to this subject). The ambivalence in institutions, its importance as competence in teachers’ training and the consistency with the low priority given to the subject in public policies are discussed.El estudio analizó la valoración de docentes universitarios de pedagogía y directores de carrera respecto a la importancia de la salud mental en la formación profesional analizando, además, los factores que podrían influir en dicha valoración. Dentro de la metodología utilizada se consideró la participación de 17 académicos (docentes y directivos) formadores de profesores de dos instituciones universitarias del sur de Chile. Para la recolección de información se utilizó una encuesta con preguntas cerradas y abiertas y entrevistas en profundidad; se analizó la información mediante análisis de contenido. Los resultados muestran que los docentes tienen, en su mayoría, una alta valoración personal del tema ( = 2.8, entre 0 y 3), existiendo una valoración ambivalente por parte de las instituciones; bajo conocimiento y dominio conceptual y procedimental, de los pedagogos, y baja prioridad como competencia en su formación (59% desconoce la existencia de asignaturas o programas en la carrera). Se discute acerca de la ambivalencia que presentaría en las instituciones, su importancia como competencia en la formación docente y la consistencia con la escasa importancia dada, en general, al tema a nivel de política pública.El estudio analizó la valoración de docentes universitarios de pedagogía y directores de carrera respecto a la importancia de la salud mental en la formación profesional analizando, además, los factores que podrían influir en dicha valoración. Dentro de la metodología utilizada se consideró la participación de 17 académicos (docentes y directivos) formadores de profesores de dos instituciones universitarias del sur de Chile. Para la recolección de información se utilizó una encuesta con preguntas cerradas y abiertas y entrevistas en profundidad; se analizó la información mediante análisis de contenido. Los resultados muestran que los docentes tienen, en su mayoría, una alta valoración personal del tema ( = 2.8, entre 0 y 3), existiendo una valoración ambivalente por parte de las instituciones; bajo conocimiento y dominio conceptual y procedimental, de los pedagogos, y baja prioridad como competencia en su formación (59% desconoce la existencia de asignaturas o programas en la carrera). Se discute acerca de la ambivalencia que presentaría en las instituciones, su importancia como competencia en la formación docente y la consistencia con la escasa importancia dada, en general, al tema a nivel de política pública

Economy and Environmental Problems in the Mexican Coastal States

A canonical correspondence analysis (CCA) for environmental and economic variables was performed for 17 Mexican coastal states. The ordination method allowed us to identify three groups, namely hydroelectric energy generation (I), pollution (II) and harbours (III), which were associated to different human activities. Furthermore, CCA is efficient to help us generate hypotheses for future research. It is therefore advised that CCA should be used for routine analyses into economics.Coastal States of Mexico, Canonical Correspondence Analysis, Diversity Index, Economic Development, Environmental Variables.

Interplay between excitation kinetics and reaction-center dynamics in purple bacteria

Photosynthesis is arguably the fundamental process of Life, since it enables energy from the Sun to enter the food-chain on Earth. It is a remarkable non-equilibrium process in which photons are converted to many-body excitations which traverse a complex biomolecular membrane, getting captured and fueling chemical reactions within a reaction-center in order to produce nutrients. The precise nature of these dynamical processes -- which lie at the interface between quantum and classical behaviour, and involve both noise and coordination -- are still being explored. Here we focus on a striking recent empirical finding concerning an illumination-driven transition in the biomolecular membrane architecture of {\it Rsp. Photometricum} purple bacteria. Using stochastic realisations to describe a hopping rate model for excitation transfer, we show numerically and analytically that this surprising shift in preferred architectures can be traced to the interplay between the excitation kinetics and the reaction center dynamics. The net effect is that the bacteria profit from efficient metabolism at low illumination intensities while using dissipation to avoid an oversupply of energy at high illumination intensities.Comment: 21 pages, 13 figures, accepted for publication in New Journal of Physic

Educational Accountability: High and Low Points of Its Implementation and Challenges for Latin America

Este trabajo busca avanzar en esta discusión existente respecto del aporte del mecanismo de accountability educacional al desarrollo de procesos de mejoramiento escolar. Para ello, se realizó una revisión de estudios de implementación de políticas educativas que incorporan accountability, preguntándose qué elementos de éste favorecen o difi cultan el mejoramiento escolar, enfatizando la relación de estos hallazgos con los contextos en que se han aplicado estas políticas. Al fi nal del trabajo, se incluye una discusión de los resultados de la revisión y proyecciones para el análisis de este fenómeno en América Latina. This work is intended to propel forward the current discussion regarding the contribution of the educational accountability mechanism to the development of school improvement processes. A literature review of a set of implementation studies of educational policies that incorporate educational accountability was conducted to discover what elements of this mechanism help or hinder educational improvement in the specifi c contexts in which they are applied. A discussion of the results of this review and projections for Latin America are presented at the end of the paper.

Predicting Recurrence and Progression in Patients with Non-Muscle-Invasive Bladder Cancer : Systematic Review on the Performance of Risk Stratification Models

BACKGROUND: Several classifications have been reported to stratify non-muscle-invasive bladder cancer (NMIBC) in risk groups according to the probability of recurrence and progression. OBJECTIVE: To systematically review the current evidence regarding risk stratification of NMIBC. METHODS: The systematic review was performed in accordance with the PRISMA statement. Studies providing data on development and/or external validation cohorts of models and risk stratification tables for recurrence and/or progression for patients with NMIBC, reporting at least one discrimination measure (AUC or C-Index) were included. RESULTS: Twenty-five studies involving 22,737 patients were included. Six classifications were identified, three of them were predictive models (EORTC, CUETO, EAU 2021) and three were based on expert opinion (EAU 2020, AUA, NCCN). A high risk of bias was present in the majority of the studies. Certain heterogenicity was found among the studies regarding adjuvant therapy, postoperative instillation or second resection. The definition of oncological outcomes was not standardized in the included studies. CUETO and EORTC scoring systems are the most validated. In general, validations showed a poor discrimination capability to predict recurrence, slightly better for progression. The EAU 2021 model overestimates the risk of progression in patients treated with BCG. Carcinoma in situ is underrepresented in all the studies analyzed. CONCLUSIONS: The existing classifications show poor discrimination capability for recurrence and possibly helpful discrimination capability for progression in NMIBC patients. These results highlight the unmet need to develop novel accurate risk models for patients with NMIBC, which could be improved with the combination of clinicopathological and molecular information

Sex-differences in the oxygenation levels of intercostales and vastus lateralis muscles during incremental exercise

This study aimed to examine sex differences in oxygen saturation in respiratory (SmO2-m.intercostales) and locomotor muscles (SmO2-m.vastus lateralis) while performing physical exercise. Twenty-five (12 women) healthy and physically active participants were evaluated during an incremental test with a cycle ergometer, while ventilatory variables (lung ventilation [V ̇E], tidal volume [Vt], and respiratory rate [RR]) were acquired through the breath-by-breath method. SmO2 was acquired using the MOXY devices on the m.intercostales and m.vastus lateralis. A two-way ANOVA (sex × time) indicated that women showed a greater significant decrease of SmO2-m.intercostales, and men showed a greater significant decrease of SmO2-m.vastus lateralis. Additionally, women reached a higher level of ΔSmO2-m.intercostales normalized to V ̇E (L·min-1) (p<0.001), whereas men had a higher level of ΔSmO2-m.vastus lateralis normalized to peak workload-to-weight (watts·kg-1, PtW) (p=0.049), as confirmed by Student's t-test. During an incremental physical exercise, women experienced a greater cost of breathing, reflected by greater deoxygenation of the respiratory muscles, whereas men had a higher peripheral load, indicated by greater deoxygenation of the locomotor muscles