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1.
Plant Foods for Human Nutrition - The effects of cocoa-derived polyphenols on cognitive functions have been analyzed through numerous studies using different interventions (doses, vehicles, time...  相似文献   
2.
Octopus maya is a carnivorous species and protein is the main energy source. During the present study, two different dietary protein levels (40 and 60% CP) were offered to octopuses as specifically designed artificial diets, to determine protein needs and the effects on metabolism. Frozen crab (Callinectes spp.) was used as control. Results obtained demonstrated that crab remains as one of the best diets for O. maya. The artificial diet with 60% CP produced a low but positive growth rate, and at times, a physiological response similar to that observed in octopuses fed crabs. The present results show the capacity of O. maya juveniles to adjust their digestive enzymes to different types of food and protein level, and this appears to be well correlated with octopus growth. General proteases and trypsin from the pancreas were well correlated with growth rates. A low activity was observed in octopuses fed 40% PC diet (negative growth rate), while a high activity was present in octopuses fed 60% CP diet and crabs (low and high growth rate, respectively). In contrast, these same enzymes were inducted in the salivary glands of octopuses fed with the diet that promoted weight loss (40% CP diet), while a reduced activity was observed in octopuses fed crabs. Energy budget indicates that the animals ingested more than 1,000 kJ week−1 kg−1; with such energy, octopuses should satisfy their physiological demands such as was observed when animals were fed crab (I = 1,300 kJ week−1 kg−1; P = 834 kJ week−1 kg−1). However, a very low digested energy was observed in octopuses the fed artificial diets, indicating that these could have a factor that limits digestibility.  相似文献   
3.
Agaves are long-lived semelparous plants that produce a high number of seeds, in dehiscent capsules, on the apical section of a stalk, up to 5 m long, after 8–25 years. These and other characteristics such as yield and yield components are scarcely evaluated in the plants of the Agave genus. The objective of this study was to quantify the capsules and seeds yield of A. salmiana Otto ex Salm-Dyck plants simultaneously maturing and growing in the same region. Infructescences of three plants simultaneously growing at San Luis Potosí, Mexico, were harvested. On them we evaluated the number of umbels, capsules and seeds (normal and sterile) and their mass per plant. The study was developed on a completely randomized design with each infructescence as an experimental unit. Also, the type distribution of the number and mass of these yield components along the stalk was evaluated with the Chi square test for goodness of fit, the Shapiro–Wilks for normality tests, asymmetry and kurtosis. Data were analyzed with the ANOVA and multiple comparisons by the Tukey test (p?≤?0.05). The number of umbels per plant (17–25), capsule per umbel (2–179) and per plant (554–1990), normal seed per capsule (0–297), normal seeds per plant (30,610–186,209) and sterile seeds per plant (211,059–619,251) widely and significantly varied among infructescences. Biomass of capsules per plant umbel (3–795 g), biomass of sterile and normal seeds per capsule (0.071–1.449 and 0–3.320 g), per umbel (0.34–97.76 and 0.21–185.26 g) and per plant (182–1052 and 334–2069 g) also varied widely. Seed yield was statistically different between plants simultaneously growing and maturing at the same site.  相似文献   
4.
In a pear orchard, when leaf senescence occurs, nitrogen (N) is added to the soil by the fallen leaves and can be re-used by the tree after undergoing decomposition and mineralization processes. Studies on leaf decomposition and N mineralization in orchards are scarce but essential to understand the N balance in the tree–soil ecosystem in a sustainable or precision agriculture. This study aimed to quantify the contribution of pear tree senescent leaves to N cycling in the orchard and its re-cycling by the crop. ‘Rocha’ pear unlabelled leaves were incubated in situ using the litter-bag technique and 15N-enriched leaves were placed at the soil surface in undisturbed confined cores.One- to six-year-old pear trees returned to the soil between 1 kg N ha?1 year?1 and 6 kg N ha?1 year?1 from senescent leaves that decomposed at rates varying from 0.0025 day?1 (d?1) to 0.0047 d?1 (estimated by both techniques, respectively). In the litter-bags, after 506–641 days, only 18–35% of initial DW was recovered in the soil, whereas in the soil cores the weight loss was higher, resulting in only 30–6% of initial DW after 398–406 d. After this period, between 36% and 110% of the initial N of the senescent leaves was recovered as organic 15N in the surface soil layer (0–7.5 cm), depending on climatic conditions, and being more prone to be absorbed by weeds.  相似文献   
5.
Abstract

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe (AMF). Plant growth parameters, total phenol compounds and total flavonoids were evaluated on leaves. Anthocyanin contents, soluble solids (SS), pH, titratable acidity (TA) and SS/TA ratio was evaluated in blackberries fruits. Blackberry plants were obtained from cuttings from field plants, which were distributed in soil according to a randomized complete block design with three repetitions. Treatments were vermicompost (10?g plant?1), phosphate rock (1?g plant?1), Glomus mosseae (AMF), (1?g plant?1), PR + AMF, V + PR, V +AMF, V + PR+ AMF and control without any amended. Plant height and stem diameter were measured five months after treatments, while total phenols and total flavonoids in leaves were evaluated eight months later. Anthocyanins, SS, pH, and TA were determined in blackberry fruits ten months after. Plant height was not statistically affected (p≤0.05), although total phenol compounds were higher (21.1?mg g?1 dry plant) in the V+PR+AMF treatment, whereas the V + AMF treatment produced more dry plant total flavonoids (1.4?mg g?1), compared with control plants. Blackberries produced with the vermicompost treatment had more anthocyanins (9.54?mg g?1) than control plants. Soluble solids, pH and titratable acidity were not statistically (p≤0.05) affected by any treatment.  相似文献   
6.

Purpose

Due to the modernization of the agro-industrial sector, compounds with different toxicity and effects on human health and animal have been used and consequently affecting the environment. Among them, tetracycline (TC) stands out as one of the antibiotics most commonly used worldwide. This study evaluated the TC interaction with different fractions of peat in natura and humic substances, humic acid, fulvic acid, and humin.

Materials and methods

The different fractions of the organic matter were characterized by organic matter content, elemental analysis, spectroscopic analysis (E4/E6), and nuclear magnetic resonance of carbon 13 (NMR 13C), and the interaction between TC and different fractions of organic matter was made by fluorescence spectrometry. We used the tangential ultra-filtration system for determining the complexation capability of humic substances (HSs), fulvic acids (FA), humic acids (HA), and humin (HUM) from peat with TC. Finally, we evaluated sorption kinetic experiments between TC and peat in natura.

Results and discussion

The peat samples, humic substances, FAs, HAs, and HUM were characterized by organic matter (OM), atomic ratio (H/C and C/O) calculated from elemental analysis data, functional groups quantified by NMR 13C data, and E4/E6 ratio, and the results show significant differences in the structural characteristics of the fractions of OM influenced by the type of microorganisms and environmental factors associated with this decomposition. Data analysis revealed the strongest interaction between HUM and TC (59.19 mg g?1), followed by interaction between HS and TC (43.36 mg g?1 HS). In the sorption studies, these conditions showed the best model to describe the system under consideration using the Freundlich model.

Conclusions

The results showed that the different fractions of the OM extracted from peat show different contributions that affect the bioavailability of contaminants to the environment.
  相似文献   
7.
Phytoparasitica - Soybean plants are exposed to multiple stresses during development. Co-occurring stresses can activate common defense pathways on plants, increasing end products concentrations,...  相似文献   
8.
The conflict between conservation and timber production is shifting in regions such as Biscay (Basque Country, northern Spain) where planted forests are no longer profitable without public subsidies and environmentalist claim that public subsidies should be reoriented to the regeneration of natural forest. This paper develops an approach that integrates scientific knowledge and stakeholders’ demands to provide decision-making guidelines for the development of new landscape planning strategies while considering ecosystem services. First, a participatory process was conducted to develop a community vision for the region’s sustainable future considering the opportunities and constrains provided by the landscape and its ecosystems. In the participatory process forest management was considered an important driver for the region`s landscape development and forest multi-functionality was envisioned as a feasible attractive alternative. The participatory process identified a knowledge gap on the synergies and trade-offs between biodiversity and carbon storage and how these depend on different forest types. Second, to study the existing synergies and trade-offs between biodiversity and carbon storage and disentangle the identified knowledge gap, a GIS-based research was conducted based on spatially explicit indicators. Our spatial analysis results showed that natural forests’ contribution to biodiversity and carbon storage is higher than that of the plantations with exotic species in the region. The results from the spatial analysis converged with those from the participatory process in the suitability of promoting, where possible and appropriate, natural forest ecosystems restoration. This iterative learning and decision making process is already showing its effectiveness for decision making, with concrete examples of how the results obtained with the applied approach are being included in planning and decision-making processes.  相似文献   
9.
The increase in demand for food due to the rapid population growth in recent years has raised the use of fertilizers, particularly phosphate salts. This fact has contributed to the excess amount of phosphorus species in aquatic systems. This is due to the leaching of these species present in the fertilizers applied to the soil to aquatic environments and may lead to eutrophication in these environments. Substances capable of interacting with the phosphate in the aquatic environment are promising for the reduction on the environmental impact. The humin, an insoluble fraction of humic material, has potential for phosphate retention, behaving like a chelating resin. Thus, the purpose of this research was to study the interaction between humin and phosphate. The equilibrium time between humin and phosphate was 15 min, where hydrogenionic potential (pH) 4.0 was the most effective in the interaction process. In this pH, the humin retained 33% of phosphate added. The complexing capacity of the humin-phosphate system was 11.53 mg g?1. The adsorption studies indicated that the system follows a kinetic pseudo-second-order model. The Freundlich model was the most suitable to describe the phosphate adsorption process in humin. To evaluate the humin application in real systems, humin was added to the domestic wastewater. Sixteen percent of the total phosphate was adsorbed by the humin. Based on these results, humin has the potential to phosphate retention in domestic wastewater and could be used as a chelating resin minimizing environmental impact.  相似文献   
10.
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