An Overview to the Health Benefits of Seaweeds Consumption

Currently, seaweeds are gaining major attention due to the benefits they give to our health. Recent studies demonstrate the high nutritional value of seaweeds and the powerful properties that seaweeds’ bioactive compounds provide. Species of class Phaeophyceae, phylum Rhodophyta and Chlorophyta possess unique compounds with several properties that are potential allies of our health, which make them valuable compounds to be involved in biotechnological applications. In this review, the health benefits given by consumption of seaweeds as whole food or by assumption of bioactive compounds trough natural drugs are highlighted. The use of seaweeds in agriculture is also highlighted, as they assure soils and crops free from chemicals; thus, it is advantageous for our health. The addition of seaweed extracts in food, nutraceutical, pharmaceutical and industrial companies will enhance the production and consumption/usage of seaweed-based products. Therefore, there is the need to implement the research on seaweeds, with the aim to identify more bioactive compounds, which may assure benefits to human and animal health.     

Effects of Protein Concentration,Plasticiser, and pH on the Properties of Protein Films from Whitemouth Croaker (Micropogonias furnieri) Residues

ABSTRACT

Proteins have been used extensively because of their relative abundance, nutritional qualities, and film-forming ability with a good structural integrity and mechanical properties. This study investigated the effects of protein isolate and glycerol concentration and pH on the properties of protein films obtained from Whitemouth croaker (Micropogonias furnieri) residues. The films were evaluated for mechanical properties, thickness, water solubility, water vapor permeability (WVP), and morphological properties. The lowest water solubility of the films occurred at low pHs and low glycerol concentrations. The films had high elongation and higher tensile strength when prepared with higher concentrations of protein isolate, lower concentrations of glycerol, and at lower pHs. The WVP and thickness of the films had a low correlation coefficient. The films were rough and had irregular surfaces. These results indicated that protein isolates from fish of low commercial value can be used as a component of new polymeric films for packaging. However, more studies are needed to assess their barrier action against oxygen, thermal behaviors, and their performance in different types of packaging.     

Screening and characterization of sex-specific DNA fragments in the freshwater fish matrinchã, Brycon amazonicus (Teleostei: Characiformes: Characidae)

The matrinch? Brycon amazonicus, a commercially important freshwater fish resource, has no heteromorphic sex chromosomes so far described. In the present study, we performed a screening of sex-associated DNA markers in this species, through the use of a random amplified polymorphic DNA (RAPD) assay and a genomic DNA restriction digestion analysis. DNA digestions evidenced no differences between sexes. Sixty-six random primers were used in pooled and individual DNA samples of males and females, and the analysis of the RAPD fingerprints revealed one female sex-associated band. Cloning and sequencing of this band led to the identification of two distinct DNA segments. While one of the isolated fragments showed a significant identity with a described protein gene (phosphatidylinositol glycan anchor biosynthesis, class W), the other fragment, composed of 535?bp, corresponds to a novel DNA marker. Further experiments were performed with this second DNA fragment in order to verify its sex-specificity. Data on dot blot hybridization, using total DNA of both sexes, confirmed its female-specificity in B. amazonicus. A primer set was designed based on its sequence data and used in PCR with DNA samples of this species, leading to diagnose the animals' sexes with a 100?% overall accuracy through a sequence characterized amplified region approach. No amplification results were found for two other species of the genus-B. orbignyanus and B. lundii. The obtained data can lead to the hypothesis that B. amazonicus may present heteromorphic sex chromosomes that should be in an early phase of differentiation.     

The yield pattern considering the distance to flow accumulation lines

Precision agriculture techniques imply a spatial management of fields and to do so a good understanding of the spatial and temporal variability of yield is needed. Average yield data from seven irrigated maize fields were used to study the yield pattern considering the distance of plants to flow accumulation lines. It was found that there is a significant correlation between average yield and distance to flow accumulation lines (DFL). This correlation is best represented by a polynomial function. The most common shape of the yield pattern curve considering the distance to flow accumulation lines shows that there is an increase in average yield with DFL from 0 to 12.5–17.5 m. Near the flow lines the average yield presents lower values due to drainage problems causing plant growth problems. It was also observed higher yield variability near the flow lines. For higher distances from the flow lines there is a continuous decrease in average yield due to less water availability and other variations of soil properties.     

Common Bean Productivity Following Diverse Boron Applications on Soil

Aspects related to micronutrients management are still poorly studied and need to be clarified to guarantee sustainable production. In this way, the study aimed to evaluate boron (B) fertilization effects on nutrition and production of common beans. The parameters measured were relative chlorophyll index, dry mass, boron transport, utilization and absorption efficiencies, B content, and B accumulation in plant tissues. The study showed that the dry mass production was negatively affected by B application, with linear dry mass decrease following the increase of B doses. Accordingly, it was found that the common bean cultivar Esplendor presented high absorption capacity of boron, and can reach 175 mg kg^?1. However, the high absorption caused phytotoxicity and reduced dry matter production by up to 30%, reflecting the efficiency of boron use by the plant, which was reduced in up to 75%.     

Prebiotic,probiotic, and synbiotic in the diet of Nile tilapia post-larvae during the sex reversal phase

This study evaluated the use of the prebiotic Active-MOS® (mannanoligosaccharides—Biorigin®) and two probiotics: PAS-TR® (Bacillus subtilis and Bacillus cereus var. toyoi—Imeve®) and Bioplus 2BC® (1.6 × 10¹⁰ UFC g^?1 de Bacillus subtilis and 1.6 × 10¹⁰ UFC g^?1 Bacillus licheniformis—Christian Hansen®) tested separately and together, in the diet of Nile tilapia post-larvae during the sex reversal phase. The experiment was conducted in two stages: (i) a total of 2160 3-day-old post-larvae (PL) (10.39 ± 0.85 mm and 12.28 ± 3.15 mg) were used and distributed in 24 tanks of 40 L each (3.0 PL L^?1). Growth performance, chemical analysis of carcass, bacterial recovery, and histomorphometry of intestinal villi were evaluated; (ii) 240 tilapia (4.28 ± 0.19 cm and 1.19 ± 0.09 g) from the previous experiment were used and stocked at 10 PL per aquarium. The parameters evaluated were survival and relative protection level after bacterial challenge against Aeromonas hydrophila. Six treatments with four replications in a completely randomized design were used for both experimental stages. Additives in the diet of tilapia post-larvae did not determine significant differences in growth, survival, microbiological, or histomorphometric parameters in this study. Nevertheless, after the experimental infection, advantages on the use of the additives were observed in terms of higher relative protection levels (38.10%) and relative percent survival in fish receiving Active-MOS® + Bioplus 2BC®. Therefore, we recommend the use of synbiotic (Active-MOS® + Bioplus 2BC®) in the farming of Nile tilapia PL with recurrent outbreaks of bacterial diseases during the sex reversal phase.     

Toxic effects of mercury chloride on silver catfish (Rhamdia quelen) spermatozoa

Heavy metals are highly toxic elements that are present in the environment, especially in water. Mercury chloride (HgCl₂) stands out among these compounds because of its strong ability to induce damage to any tissue with which it comes into contact. The gametes of spawning aquatic animals, such as fish, are susceptible to such damage. Thus, our objective was to evaluate the toxic potential of HgCl₂ in the capacitation and activation of Rhamdia quelen sperm. Semen was collected from seven males and activated in 58 mM sodium chloride (NaCl) containing 0 (control), 4^?10, 7^?10, 7^?9, and 7^?8 M HgCl₂. The evaluated variables included motility, vigor, motility time, morphology, membrane integrity, membrane fluidity, mitochondrial functionality, production of reactive oxygen species (ROS), and DNA fragmentation. All evaluated HgCl₂ concentrations increased primary pathologies and reduced motility, vigor and motility time. Damage to membrane integrity and fluidity began occurring at a concentration of 7^?10 M HgCl₂. These results indicate that HgCl₂ has a toxic effect on different sites of fish spermatozoa and that sperm motility decreases after exposure to HgCl₂, impairing sperm capacitation and activation.     

Spatial variability and temporal stability of apparent soil electrical conductivity in a Mediterranean pasture

The general objectives of this study were to evaluate (i) the specificity of the spatial and temporal dynamics of apparent soil electrical conductivity (EC_a) measured by a electromagnetic induction (EMI) sensor, over 7 years, in variable conditions (of soil moisture content (SMC), soil vegetation cover and grazing management) and, consequently, (ii) the potential for implementing site-specific management (SSM). The DUALEM 1S sensor was used to measure the EC_a in a 6 ha pasture experimental field four times between June 2007 and February of 2013. Soil spatial variability was characterized by 76 samples, geo-referenced with the global positioning system (GPS). The soil was characterized in terms of texture, moisture content, pH, organic matter content, nitrogen, phosphorus and potassium. This study shows a significant temporal stability of the EC_a patterns under several conditions, behavior that is an excellent indicator of reliability of this tool to survey spatial soil variability and to delineate potential site-specific management zones (SSMZ). Significant correlations were obtained in this work between the EC_a and relative field elevation, pH, silt and soil moisture content. These results open perspectives for using the EMI sensor as an indicator of SMC in irrigation management and of needs of limestone correction in Mediterranean pastures. However, it is interesting to extend the findings to other types of soil to verify the origin of the lack of correlation between the EC_a data measured by DUALEM sensor and properties such as the clay, organic matter or phosphorus soil content, fundamental parameters for establishment of pasture SSM projects.