Terrestrial-marine continuum of sedimentary natural organic matter in a mid-latitude estuarine system

Journal of Soils and Sediments - Humic acids (HA) have several environmental roles, but are particularly important in aquatic environments, being recognized as redox active natural organic matter...     

Growth response of Pinus pinaster Ait. to climatic variables in central Spanish forests

? The effect of climatic variables (temperature and precipitation) on radial growth of the Mediterranean Maritime pine (Pinus pinaster Ait.) was studied using dendrochronological techniques in the Iberian Peninsula.

? Ten tree-ring width chronologies, along the central distribution area of the species, were built. Chronology variability was analysed using Principal Component Analysis (PCA) for the period 1952–2005.

? The first principal component (PC1) explained 56% of tree-growth variability. Tree-growth association with climate was analysed at regional and local scales using correlation coefficient and bootstrapped response functions.

? Radial growth at both scales was positively correlated with rainfall during and prior to the growing season at all sites, and with summer rainfall before the growing season at five sites. Mean temperature effect changed according to the sampling site, from non-significant at the highest sites to significant (positive relationship in winter) at the lowest sites. Growth season temperature also had a negative effect.

? The Kalman filter was applied to estimate changing association between growth and climate over-time. Results suggested a change in association, initiated in the 80s, from non-significant to significant (*p < 0.05) at six of the sampling sites.

? Pinus pinaster is an accurate species for analysing tree-growth association with climate and for studying plant behaviour under global change conditions.

     

Changes in Cd,Cu, Ni,Pb and Zn Fractionation and Liberation Due to Mussel Shell Amendment on a Mine Soil

Mining activities are related to relevant environmental pollution issues that should be controlled. We used sequential extractions to fractionate Cd, Cu, Ni, Pb and Zn retained on unamended or mussel shell‐amended mine soil samples, all of them treated with a mixture of the five heavy metals (total metal concentration of 1·57 mmol L⁻¹), after 1, 7 and 30 days of incubation. In addition, we used the stirred flow chamber technique to study the release of each of the five heavy metals from these different unamended and shell‐amended soil samples. The results indicate that the shell amendment caused a decrease in the most soluble fraction, while increasing the most recalcitrant (least mobile) fraction. With equivalent implications, the stirred flow chamber experiments showed that mussel shell amendment was associated to a decrease in heavy metal release and increased retention. The highest mussel shell dose and incubation time caused the most relevant changes in pH values and thus in metal retention, also indicating the importance of pH modifications in the mechanism of retention acting in the amended samples. In view of these results, the use of mussel shell amendment can be encouraged to increase heavy metal retention in acid mine soils, in order to minimise risks of environmental pollution. Copyright © 2016 John Wiley & Sons, Ltd.     

Hypolipidemic effect in cholesterol-fed rats of a soluble fiber-rich product obtained from cocoa husks

A new soluble cocoa fiber product (SCFP), obtained after enzymatic treatment of cocoa husks, was characterized and its potential health effects studied in an animal model of dietary-induced hypercholesterolemia. The SCFP was rich in soluble dietary fiber (DF) and antioxidant polyphenols. Consumption of a cholesterol-rich diet containing the SCFP as a source of DF resulted in lower food intake and body weight gain in comparison with control groups consuming cholesterol-free or cholesterol-rich diets with cellulose as DF. The cholesterol-rich diet caused remarkable hypercholesterolemia. However, the SCFP diminished the negative impact of the cholesterol-rich diet, buffering the decrease of high density lipoprotein-cholesterol, and the increase of total and low density lipoprotein-cholesterol levels, and lipid peroxidation (malondialdehyde levels) induced by the fatty diet. The SCFP also decreased triglyceride levels to values lower than those in the group fed the cholesterol-free diet. These results put forward the potential application of the SCFP as a dietary supplement or functional food ingredient.     

Analysis of tree interactions in a mixed Mediterranean pine stand using competition indices

Studying species interactions in mixed forests allows us to assess their potential benefits and adapt current silvicultural tools developed in monospecific stands to multi-specific stands. We analyzed tree interactions in a Pinus halepensis Mill. and Pinus pinea L. mixed plantation using individual tree neighborhood models and competition indices that accounted for symmetric and asymmetric competition, to analyze whether the growth of each species was better explained by symmetric or asymmetric competition. We also split the competition indices into their intra- and interspecific forms, to test for competition effects on growth change based on competitor identity. Finally, we analyzed whether P. halepensis and P. pinea trees had different growth responses to competition. When calculating competition indices, we explored how spatial information and size of competitor trees contributed to the quantification of the process. Competition measurements were optimized to more precisely describe interactions. Results showed that the inclusion of competition indices generated important improvements in growth models. The main mode of competition was symmetric, which could be related to water restrictions typical of the Mediterranean climate. Considering competitor identity did not improve the growth models, while measurement without discriminating competitors by species generated more parsimonious models. P. halepensis and P. pinea trees had similar growth responses to competition, indicating that the two species cope with competition in similar ways. However, P. pinea showed lower average growth than P. halepensis in the period analyzed. Results suggest that preventing the onset of intense interspecific competition processes could help slow down the long-term replacement of P. pinea by P. halepensis and could have benefits for silvicultural management in systems with two species that share ecological niches but are capable of generating different goods and services.     

Use of Baru (Brazilian Almond) Waste from Physical Extraction of Oil to Produce Gluten Free Cakes

The extraction of oil from baru almonds produces a waste that carries part of their nutritional qualities and antioxidants. It can be used to produce partially deffated baru flour (PDBF). We aimed to evaluate the applicability of PDBF and the effect of the addition of xanthan gum (XG) to produce gluten free cakes. Cakes were prepared with 100 % wheat flour (WF cake) and with 100 % PDBF and four different levels of XG (0 %-PDBF cake, 0.1 %-X1, 0.2 %-X2 and 0.3 %-X3 cakes), and evaluated for composition, antioxidants, moisture, specific volume, texture and sensory acceptance. PDBF cakes showed lower carbohydrate values, but higher protein, lipids, calories and antioxidant contents. They were rich in fiber, as well as iron, zinc and copper. The replacement of WF by PDBF resulted in an increased hardness and adhesiveness and a decreased cohesiveness, elasticity and moisture. Chewiness of X2 cake was similar to that of WF cake. X2 and X3 cakes showed specific volume closer to that of WF cake. No difference was found among the treatments for texture and appearance acceptances. Flavor of X2 and X3 cakes were more accepted than WF cake. Acceptance of all cakes were in the liking region of hedonic scale. PBDF associated to XG is a feasible option to substitute WF in gluten free cake, improving its nutritional quality.

     

Histopathological Changes in Third-Instar and Adult Anastrepha ludens (Diptera: Tephritidae) After in vitro Heat Treatment

The Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), is one of the most harmful pests of mango causing direct damage by oviposition on the fruit pulp. Mango for export is subjected to hydrothermal treatment as a quarantine method for the control of this pest, but exposure to heat for long periods of time reduces considerably the quality and shelf-life of treated fruit. The aim of this work was to study morphological changes of third-instar larvae and adults of A. ludens after in vitro exposure to high temperature at sublethal times. A heating block system was used to expose larvae at 46.1°C for 19.6 and 12.9 min, producing 94.6 and 70% mortality, respectively. Treated larvae were processed for optical microscopy. A fraction of surviving treated larvae was separated into containers with artificial diet to allow development into adults. Adult sexual organs were dissected and processed for transmission electron microscopy analysis. Results showed that 94.6% of the treated larvae died at 46.1°C for 19.6 min and none of the surviving larvae eclosed to adulthood, as they developed as malformed puparia. For the in vitro treatment at 46.1°C during 12.9 min, 70% of the treated larvae died and only 3.75% reached the adult stage, but ultrastructural damage in the male testes and in the female ovaries was observed. Additionally, 11.1% of the adult flies from the in vitro treatment also showed wing malformation and were incapable of flying. The analysis showed that surviving flies were unable to reproduce.