Evolución de los ácidos grasos en el mesocarpo del níspero (Mespilus germanica. L.) a diferentes estados de maduración

The fatty acid composition of medlar (Mespilus germanica L.) varied significantly among the ripening stages sampled at 157, 172 and 187 DAFs (days after full bloom). Twenty-one different fatty acids were detected in preclimacteric fruit and 17 when the climacteric began. Principal fatty acids, determined in medlar fruit harvested from October (157 and 172 DAFs) to November (187 DAF) were mainly palmitic acid (16:0), linoleic acid (18:2n-6), and a-linolenic acid (18:3n-3). While the content of saturated fatty acids [palmitic acid (16:0) and stearic acid (18:0)] increased, the content of the essential polyunsaturated fatty acids [linoleic acid (18:2n-6) and linolenic acid (18:3n-3)] decreased through ripening, in parallel with pulp darkening. The percentage of linoleic acid and a-linolenic acid in ripe, hard fruits was 60.0 and 13.5 % of dry wt at 157 DAF which decreased throughout ripening, remaining at 28.7 and 5.6 % of dry wt, respectively, in the fully softened and darkened pulp. A marked decreases in the double bond index, percentage of unsaturation and the ratio of unsaturation/saturation were also seen throughout the medlar ripening. The contribution of unsaturated fatty acid to the total fatty acid content decreased markedly as the medlar fruit became progressively softer and darkened.La composición en ácidos grasos del níspero (Mespilus germanica L.) varió significativamente entre los estados de maduración muestreados a los 157, 172 y 187 DAFs (días después de la floración). Veinte y un ácidos grasos diferentes fueron detectados en el fruto preclimatérico y 17 cuando comenzó el climaterio. Los ácidos grasos principales encontrados en nísperos, recolectados desde Octubre (157 y 172 DAFs) hasta Noviembre (187 DAF), fueron principalmente ácido palmítico (16:0), ácido linoléico (18:2n-6), y ácido a-linolénico (18:3n-3). En tanto que el contenido en ácidos grasos saturados (ácido palmítico (16:0) y ácido esteárico (18:0)) aumentó, el contenido en ácidos grasos esenciales (ácido linoleico (18:2n-6) y ácido linolénico (18:3n-6)) disminuyó durante la maduración, en paralelo con el oscurecimiento de la pulpa. El porcentaje de ácido linoleico y de ácido a-linolénico en frutos maduros sin reblandecer fue de 60.0 y 13.5 % del peso seco a 157 DAF, disminuyendo durante la maduración, y permaneciendo a 28.7 y 56 % del peso seco, respectivamente, en la pulpa completamente blanda y oscura. También se observó durante la maduración del níspero una marcada disminución en el número de dobles enlaces, en el tanto por ciento de instauración y en la relación instauración / saturación. La contribución de los ácidos grasos insaturados al contenido de ácidos grasos totales disminuyó marcadamente cuando el níspero comenzó progresivamente a reblandecerse y oscurecerse

Phase angle correlates with n-3 fatty acids and cholesterol in red cells of Nigerian children with sickle cell disease

OBJECTIVE: To determine the cholesterol content and fatty acid composition of red cell membrane phospholipids (PL) of children with sickle cell disease (SCD) and to correlate these levels with whole body phase angle that is related to the integrity and function of cell membranes. STUDY DESIGN: Blood samples were obtained from 69 children with SCD and 72 healthy age- and gender-matched controls in Nigeria for the determination of the cholesterol content and proportions of fatty acids in red cell PL. Bioelectrical impedance analysis was used to obtain resistance (R) and reactance (Xc) from which phase angle was calculated as arctan Xc/R. Cholesterol (normalized to lipid phosphorus) and the proportions of individual fatty acids were correlated with phase angle. RESULTS: The proportions of palmitic (p < 0.001), stearic acid (p = 0.003) and cholesterol (p < 0.001) were significantly higher in the red cells of children with SCD, whereas the proportions of arachidonic acid and docosahexaenoic acid were reduced (p = 0.03 and < 0.001, respectively) compared to controls. The phase angle was inversely correlated with the proportions of palmitic acid (p = 0.03) and oleic acid (p < 0.001) and cholesterol (p = 0.003). Three n-3 polyunsaturated fatty acids-eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid- were positively correlated with phase angle (p < 0.001). CONCLUSIONS: The fatty acid composition and cholesterol content of tissue membranes in SCD correlate with the phase shift measured by bioelectrical impedance analysis. Phase angle measurements may provide a non-invasive method for monitoring interventions aimed at altering the lipid composition of membranes

Towards A Microgrid Based Residential Home Energy Management Using Genetic Algorithm

This paper proposes a load scheduling approach for a residential home in an islanded PV microgrid scenario based on a Genetic Algorithm (GA). The primary aim is to inform on how a Demand Side Management (DSM) could reduce the capital cost of the residential home energy use and operational cost of the microgrid by minimizing the use of fossil fuel generator. The research study proposes and describes the design for load allocation to achieve utilization of solar PV resources optimally. The proposed scheme is based on the time-of-use (TOU) and improvement of electricity users' comfort. The demonstration of the concept is presented and discussed based on a single smart home scenario using a solar PV microgrid and battery in a rural community of Enugu State, Nigeria

How conservation initiatives go to scale

Although a major portion of the planet’s land and sea is managed to conserve biodiversity, little is known about the extent, speed and patterns of adoption of conservation initiatives. We undertook a quantitative exploration of how area-based conservation initiatives go to scale by analysing the adoption of 22 widely recognized and diverse initiatives from across the globe. We use a standardized approach to compare the potential of different initiatives to reach scale. While our study is not exhaustive, our analyses reveal consistent patterns across a variety of initiatives: adoption of most initiatives (82% of our case studies) started slowly before rapidly going to scale. Consistent with diffusion of innovation theory, most initiatives exhibit slow–fast–slow (that is, sigmoidal) dynamics driven by interactions between existing and potential adopters. However, uptake rates and saturation points vary among the initiatives and across localities. Our models suggest that the uptake of most of our case studies is limited; over half of the initiatives will be taken up by <30% of their potential adopters. We also provide a methodology for quantitatively understanding the process of scaling. Our findings inform us how initiatives scale up to widespread adoption, which will facilitate forecasts of the future level of adoption of initiatives, and benchmark their extent and speed of adoption against those of our case studies

Biodiversity patterns of Arctic diatom assemblages in lakes and streams: Current reference conditions and historical context for biomonitoring

Comprehensive assessments of contemporary diatom distributions across the Arctic remain scarce. Furthermore, studies tracking species compositional differences across space and time, as well as diatom responses to climate warming, are mainly limited to paleolimnological studies due to a lack of routine monitoring in lakes and streams across vast areas of the Arctic. The study aims to provide a spatial assessment of contemporary species distributions across the circum-Arctic, establish contemporary biodiversity patterns of diatom assemblages to use as reference conditions for future biomonitoring assessments, and determine pre-industrial baseline conditions to provide historical context for modern diatom distributions. Diatom assemblages were assessed using information from ongoing regulatory monitoring programmes, individual research projects, and from surface sediment layers obtained from lake cores. Pre-industrial baseline conditions as well as the nature, direction and magnitude of changes in diatom assemblages over the pastc.200 years were determined by comparing surface sediment samples (i.e. containing modern assemblages) with a sediment interval deposited prior to the onset of significant anthropogenic activities (i.e. containing pre-1850 assemblages), together with an examination of diatoms preserved in contiguous samples from dated sediment cores. We identified several biotypes with distinct diatom assemblages using contemporary diatom data from both lakes and streams, including a biotype typical for High Arctic regions. Differences in diatom assemblage composition across circum-Arctic regions were gradual rather than abrupt. Species richness was lowest in High Arctic regions compared to Low Arctic and sub-Arctic regions, and higher in lakes than in streams. Dominant diatom taxa were not endemic to the Arctic. Species richness in both lakes and streams reached maximum values between 60 degrees N and 75 degrees N but was highly variable, probably reflecting differences in local and regional environmental factors and possibly sampling effort. We found clear taxon-specific differences between contemporary and pre-industrial samples that were often specific to both ecozone and lake depth. Regional patterns of species turnover (beta-diversity) in the pastc.200 years revealed that regions of the Canadian High Arctic and the Hudson Bay Lowlands to the south showed most compositional change, whereas the easternmost regions of the Canadian Arctic changed least. As shown in previous Arctic diatom studies, global warming has already affected these remote high latitude ecosystems. Our results provide reference conditions for future environmental monitoring programmes in the Arctic. Furthermore, diatom taxa identification and harmonisation require improvement, starting with circum-Arctic intercalibrations. Despite the challenges posed by the remoteness of the Arctic, our study shows the need for routine monitoring programmes that have a wide geographical coverage for both streams and lakes