Publications

Abstract The availability of a large number of high‐density markers (SNPs) allows the estimation of historical effective population size ( N e ) from linkage disequilibrium between loci. A recent refinement of methods to estimate historical N e from the recent past has been shown to be rather accurate with simulation data. The method has also been applied to real data for numerous species. However, the simulation data cannot encompass all the complexities of real genomes, and the performance of any estimation method with real data is always uncertain, as the true demography of the populations is not known. Here, we carried out an experimental design with Drosophila melanogaster to test the method with real data following a known demographic history. We used a population maintained in the laboratory with a constant census size of about 2800 individuals and subjected the population to a drastic decline to a size of 100 individuals. After a few generations, the population was expanded back to the previous size and after a few further generations again expanded to twice the initial size. Estimates of historical N e were obtained with the software GONE both for autosomal and X chromosomes from samples of 17 individuals sequenced for the whole genome. Estimates of the historical effective size were able to infer the patterns of changes that occurred in the populations showing generally good performance of the method. We discuss the limitations of the method and the application of the software carried out so far.

Seaweeds are a typical food of East-Asian cuisine, to which are alleged several beneficial health effects have been attributed. Their availability and their nutritional and chemical composition have favored the increase in its consumption worldwide, as well as a focus of research due to their bioactive properties. In this regard, seaweed proteins are nutritionally valuable and comprise several specific enzymes, glycoproteins, cell wall-attached proteins, red algae phycobiliproteins, lectins, peptides, or mycosporine-like amino acids. This great extent of molecules has been reported to exert significant antioxidant, antimicrobial, anti-inflammatory, antihypertensive, antidiabetic, or antitumoral properties. Hence, knowledge on algae proteins and derived compounds have gained special interest for the potential nutraceutical, cosmetic or pharmaceutical industries based on these bioactivities. Although several molecular mechanisms of action on how these proteins and peptides exert biological activities have been described, many gaps in knowledge still need to be filled. Updating the current knowledge related to seaweed proteins and peptides is of interest to further asses their potential health benefits. This review addresses the characteristics of seaweed protein and protein-derived molecules, their natural occurrence, their studied bioactive properties, and their described potential mechanisms of action.

Retention and release kinetics of Cu on four acid Typic haplumbrepts developed on two different types of parent rock material (granite and amphibolite) were studied with a stirred‐flow chamber (SFC) method. The granitic soils were lower in organic material and lower in Fe and Al oxides than the soils formed in amphibolite. The kinetic parameters were assessed in four consecutive Cu retention–release cycles by alternately applying pulses of solutions with and without Cu. Granite soils showed lower total Cu retention (7–12 mmol kg −1 ) than amphibolite soils (16–21 mmol kg −1 ) after one single pulse application of 0.0787 mmol Cu L −1 at pH 5.5, which may be due to differences in their organic and oxides compositions. The amount of Cu retained diminished to 40 to 25% in the third retention cycle relative to the first, suggesting that the soils' Cu retention depends on the previous metal loading. Conversely, the released Cu was approximately 20% of that retained in the first cycle, but the amounts released were similar for all cycles and all soils. The results obtained were fitted using a first‐order equation for both retention and release of Cu. In the first cycle, first order rate coefficients of retention ranged from 0.084 to 0.56 min −1 , and increased by about a factor of two in the next cycle. Release rate coefficients were more than 10 times lower than those of retention, and less dependent on the previous metal loading. The process of retention and release of Cu was found to be hysteretic, which suggest that the desorption mechanism or path is not an exact opposite of the adsorption mechanism or path.

Abstract Background The plant growth is influenced by multiple interactions with biotic (microbial) and abiotic components in their surroundings. These microbial interactions have both positive and negative effects on plant. Plant growth promoting bacterial (PGPR) interaction could result in positive growth under normal as well as in stress conditions. Methods Here, we have screened two PGPR’s and determined their potential in induction of specific gene in host plant to overcome the adverse effect of biotic stress caused by Magnaporthe grisea , a fungal pathogen that cause blast in rice. We demonstrated the glucanase protein mode of action by performing comparative modeling and molecular docking of guanosine triphosphate (GTP) ligand with the protein. Besides, molecular dynamic simulations have been performed to understand the behavior of the glucanase-GTP complex. Results The results clearly showed that selected PGPR was better able to induce modification in host plant at morphological, biochemical, physiological and molecular level by activating the expression of β-1,3-glucanases gene in infected host plant. The docking results indicated that Tyr75, Arg256, Gly258, and Ser223 of glucanase formed four crucial hydrogen bonds with the GTP, while, only Val220 found to form hydrophobic contact with ligand. Conclusions The PGPR able to induce β-1,3-glucanases gene in host plant upon pathogenic interaction and β-1,3-glucanases form complex with GTP by hydrophilic interaction for induction of defense cascade for acquiring resistance against Magnaporthe grisea. Graphical abstract

Ultrasound-assisted extraction (UAE) is introduced to upper-level analytical chemistry students as a simple strategy focused on sample preparation for trace-metal determination in biological tissues. Nickel extraction in seafood samples and quantification by electrothermal atomic absorption spectrometry (ETAAS) are carried out by a team of four students. The experiment covers (i) the study of variables influencing the extraction process (sonication time, ultrasound amplitude, acid concentration, particle size, and sample mass) and the selection of optimal conditions; (ii) the determination of analytical characteristics and method validation using certified reference materials; and (iii) the analysis of seafood samples (i.e., mussels, prawns, hake, and sole).