Modeling the vacuolar storage of malate shed lights on pre- and post-harvest fruit acidity

Background: Malate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. Several studies suggest that malate accumulation in fruit cells is controlled at the level of vacuolar storage. However, the regulation of vacuolar malate storage throughout fruit development, and the origins of the phenotypic variability of the malate concentration within fruit species remain to be clarified. In the present study, we adapted the mechanistic model of vacuolar storage proposed by Lobit et al. in order to study the accumulation of malate in pre and postharvest fruits. The main adaptation concerned the variation of the free energy of ATP hydrolysis during fruit development. Banana fruit was taken as a reference because it has the particularity of having separate growth and post-harvest ripening stages, during which malate concentration undergoes substantial changes. Moreover, the concentration of malate in banana pulp varies greatly among cultivars which make possible to use the model as a tool to analyze the genotypic variability. The model was calibrated and validated using data sets from three cultivars with contrasting malate accumulation, grown under different fruit loads and potassium supplies, and harvested at different stages. Results: The model predicted the pre and post-harvest dynamics of malate concentration with fairly good accuracy for the three cultivars (mean RRMSE = 0.25-0.42). The sensitivity of the model to parameters and input variables was analyzed. According to the model, vacuolar composition, in particular potassium and organic acid concentrations, had an important effect on malate accumulation. The model suggested that rising temperatures depressed malate accumulation. The model also helped distinguish differences in malate concentration among the three cultivars and between the pre and post-harvest stages by highlighting the probable importance of proton pump activity and particularly of the free energy of ATP hydrolysis and vacuolar pH. Conclusions: This model appears to be an interesting tool to study malate accumulation in pre and postharvest fruits and to get insights into the ecophysiological determinants of fruit acidity, and thus may be useful for fruit quality improvement. (Résumé d'auteur

Consensus on the definition and criteria for failure of surgical treatment in bacterial arthritis of a native joint. An international Delphi study

Abstract PurposeThe literature presents a wide range of success rates for a single surgical intervention of bacterial‐septic‐arthritis, and there is a lack of clear criteria for identifying treatment failure and making decisions about reintervention. This Delphi study aims to establish a consensus among an international panel of experts regarding the definition of treatment failure and the criteria for reintervention in case of bacterial arthritis.MethodsThe conducting and reporting Delphi studies (CREDES) criteria were used. Data from a systematic review was provided as the basis for the study. A list of 100 potential experts were identified. The study was designed and conducted as follows: (I) identification and invitation of an expert panel, (II) informing the participating expert panel on the research question and subject, and (III) conducting two or three Delphi rounds to reach consensus on explicit research items. Potential criteria were rated on a five‐point Likert scale.ResultsSixty orthopaedic experts from nine countries participated in this Delphi study, with 55 completing all three rounds. The mean experience as an orthopaedic surgeon was 15 years (SD ± 9). Strong (96%) consensus was reached on the definition of treatment failure: the persistence of physical signs of arthritis (e.g., pain and swelling) and/or systemic inflammation (e.g., fever and no improvement in CRP) despite surgical and antibiotic treatment. Furthermore, consensus (>80%) was reached on six criteria influencing the decision for reintervention; pain (81%), sepsis (98%), fever (88%), serum CRP (93%), blood culture (82%), and synovial fluid culture (84%).ConclusionThe definition of treatment failure for bacterial arthritis after a single surgical intervention was established through a three‐round Delphi study. Additionally, consensus was reached on six criteria that are helpful for determining the need for reintervention. This definition and these criteria may help in the development of clinical guidelines, and will empower physicians to make more precise and consistent decisions regarding reintervention for patients, ultimately aiming to reduce over‐ and undertreatment and improve patient outcomes.Level of EvidenceLevel V

Tendencias de la cultura y cambio organizacional: estudio de caso

La imagen corporativa en relación con el medio se evidencia en el informe de Deloitte (2018) sobre tendencias del capital humano, en donde se reportan alrededor de 11.000 cuestionarios aplicados a gerentes de 140 países y 150 líderes de empresas colombianas, el planteamiento realizado sugiere que el capital social cobra tanto importancia como el físico y el financiero. Estos aspectos están relacionados con la identidad corporativa y cómo se relaciona a su vez con la cultura y la gestión del en la organización. La cultura y la gestión del cambio han cobrado mucho interés para las personas que guían las organizaciones, los estudios realizados por Deloitte en 2017 se focalizaron en la relación de la cultura y el compromiso como elementos importantes del empleado; los resultados del estudio dejan en evidencia cómo la habilidad de las organizaciones para afrontar inconvenientes de compromiso y cultura tenían una reducción del 14% con respecto al año anterior, estos datos permiten entender la complejidad del ambiente en el ámbito laboral y dan cuenta de la importancia de desarrollar conocimiento válido que oriente a académicos y empresarios para que puedan abordar de una manera adecuada estos aspectos.1a edició

The determination of micro quantities of manganese in plant material.

After a liquid-liquid extraction with 2-thenoyltrifluoro-acetone, micro quantities of Mn in plant material can be determined with formaldoxime without interference from other elements. [A.S. (Abstract retrieved from CAB Abstracts by CABI’s permission)</jats:p

Determination of micro-quantities of magnesium.

To 25 ml or less of a neutral sample (containing up to 20 gamma Mg) in a 150ml separating funnel, 10 ml tartrate solution, 10 ml boric-acid buffer and 5 ml Na diethyldithiocarbamate are added and the solution made up to 50 ml. After extracting with 25 ml chloroform and discarding the organic phase the water phase is rinsed with about 10 ml chloroform and the organic phase again discarded. 10 ml of masking agent, 1 ml n-butylamine and 10 ml extracting solution (8-hydroxyquinoline in chloroform) are then added. After shaking and separating the organic phase a knife point of Na2SO4 is added and the extinction of the samples and that of a l0 gamma Mg standard are measured against a simultaneously treated reagent blank at 380 nm. (Abstract retrieved from CAB Abstracts by CABI’s permission)</jats:p