Evaluation of a modified QuEChERS extraction of multiple classes of pesticides from a rice paddy soil by LC-APCI-MS/MS

A new method for the determination of clomazone, fipronil, tebuconazole, propiconazole, and azoxystrobin in samples of rice paddy soil is presented. The extraction of the pesticides from soil samples was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Some extraction conditions such as salt addition, sample acidification, use of buffer, and cleanup step were evaluated. The optimized method dealt with a single extraction of the compounds under study with acidified acetonitrile, followed by the addition of MgSO(4) and NaCl prior to the final determination by liquid chromatography-atmospheric chemical pressure ionization-tandem mass spectrometry. Validation studies were carried out in soil samples. Recoveries of the spiked samples ranged between 70.3 and 120% with relative standard deviation lower than 18.2%. The limits of quantification were between 10 and 50 μg kg(-1). The method was applied to the analysis of real samples of soils where rice is cultivated.     

The Prospective Use of Brazilian Marine Macroalgae in Schistosomiasis Control

Schistosomiasis is a parasitic disease that affects more than 250 million people. The treatment is limited to praziquantel and the control of the intermediate host with the highly toxic molluscicidal niclosamide. Marine algae are a poorly explored and promising alternative that can provide lead compounds, and the use of multivariate analysis could contribute to quicker discovery. As part of our search for new natural compounds with which to control schistosomiasis, we screened 45 crude extracts obtained from 37 Brazilian seaweed species for their molluscicidal activity against Biomphalaria glabrata embryos and schistosomicidal activities against Schistosoma mansoni. Two sets of extracts were taxonomically grouped for metabolomic analysis. The extracts were analyzed by GC–MS, and the data were subjected to Pattern Hunter and Pearson correlation tests. Overall, 22 species (60%) showed activity in at least one of the two models. Multivariate analysis pointed towards 3 hits against B. glabrata veliger embryos in the Laurencia/Laurenciella set, 5 hits against B. glabrata blastula embryos, and 31 against S. mansoni in the Ochrophyta set. Preliminary annotations suggested some compounds such as triquinane alcohols, prenylated guaianes, dichotomanes, and xenianes. Despite the putative identification, this work presents potential candidates and can guide future isolation and identification.     

Iron Mobilization and Mineralogical Alterations Induced by Iron-Deficient Cucumber Plants (Cucumis sativus L.) in a Calcareous Soil

Dicotyledons cope with ion (Fe) shortage by releasing low-molecular-weight organic compounds into the rhizosphere to mobilize Fe through reduction and complexation mechanisms. The effects induced by these root exudates on soil mineralogy and the connections between Fe mobilization and mineral weathering processes have not been completely clarified. In a batch experiment, we tested two different kinds of organic compounds commonly exuded by Fe-deficient plants, i.e., three organic acids (citrate, malate, and oxalate) and three flavonoids (rutin, quercetin, and genistein), alone or in combination, for their ability to mobilize Fe from a calcareous soil and modify its mineralogy. The effect of root exudates on soil mineralogy was assessed in vivo by cultivating Fe-deficient and Fe-sufficient cucumber plants (Cucumis sativus L.) in a RHIZOtest device. Mineralogical analyses were performed by X-ray powder diffraction. The batch experiment showed that citrate and, particularly, rutin (alone or combined with organic acids or genistein) promoted Fe mobilization from the soil. The combinations of rutin and organic acids modified the soil mineralogy by dissolving the amorphous fractions and promoting the formation of illite. These mineralogical alterations were significantly correlated with the amount of Fe mobilized from the soil. The RHIZOtest experiment revealed a drastic dissolution of amorphous components in the rhizosphere soil of Fe-deficient plants, possibly caused by the intense release of phenolics, amino acids, and organic acids, but without any formation of illite. Both batch and RHIZOtest experiments proved that exudates released by cucumber under Fe deficiency concurred to the rapid modification (on a day-scale) of the mineralogy of a calcareous soil.     

Offshore currents explain the discontinuity of a fish community in the seagrass bed along the Japanese archipelago

Oceanographic conditions can affect spatial variability in fish community structures by influencing the temperature‐dependent latitudinal distribution of adult fishes and transport during their young stages. In order to examine latitudinal variability in the fish community structure within a single coastal ecosystem, quantitative sampling was conducted in the sub‐tidal zone of seagrass Zostera marina beds over a broad latitudinal scale (31.31–43.0°N: from subtropical to sub‐boreal zones, covering 80% of the latitudinal range of seagrass distribution in Japan) in the western North Pacific based on a uniform methodology. Cluster analysis with the similarity of fish communities showed that 13 sampling sites were divided into two clusters. The border between the two clusters corresponded with the area of mixing of two dominant currents, Oyashio and Kuroshio, which form a border between the warm temperate zone and the cool temperate zone off the Pacific coast of Japan. Oceanographic properties, such as major currents off the coast, are suggested to affect the latitudinal variability in the fish communities in the coastal ecosystem in the western North Pacific.     

Morphological changes,peptidase activity,and effects of exogenous enzymes in the early ontogeny of Nile tilapia,Oreochromis niloticus

Aquaculture International - During the early ontogeny, the transition from endogenous (yolk protein) to exogenous feeding (artificial diets) represents a critical period linked to the...     

Effect of Organic Acids on Physical-Mechanical and Antifungicidal Properties of Anchovy Protein Films

The use of active biodegradable films from renewable sources like anchovy, with the incorporation of organic acids, such as sorbic acid (SA) and benzoic acid (BA), is an alternative to decrease environmental pollution and minimize the development of fungi in foods. This study investigated the respective influences of SA and BA at 0, 0.50, 0.75, and 1.50% on the growth of Aspergillus flavus and Rhizopus oryzae and on Argentine anchovy protein film properties (L*, a*, b*, tensile strength, elongation at break, solubility in water, water vapor permeability, and Fourier transform infrared spectroscopy (FTIR)). Results showed that the incorporation of SA or BA at different levels significantly increased the water vapor permeability, water solubility, and elongation at break of the films, but decreased the tensile strength and L* parameter (p < 0.05). FTIR evidenced an interaction between the BA and Argentine protein isolate. Also, the influences of the SA or BA concentration on antifungal activity was observed. The greatest effectiveness was obtained for films containing SA against R. oryzae compared to BA film treatments. In conclusion, the Argentine anchovy protein films could retain their antifungal property by incorporation of these organic acids.     

Algal-Derived Halogenated Sesquiterpenes from Laurencia dendroidea as Lead Compounds in Schistosomiasis Environmental Control

Schistosomiasis has been controlled for more than 40 years with a single drug, praziquantel, and only one molluscicide, niclosamide, raising concern of the possibility of the emergence of resistant strains. However, the molecular targets for both agents are thus far unknown. Consequently, the search for lead compounds from natural sources has been encouraged due to their diverse structure and function. Our search for natural compounds with potential use in schistosomiasis control led to the identification of an algal species, Laurencia dendroidea, whose extracts demonstrated significant activity toward both Schistosoma mansoni parasites and their intermediate host snails Biomphalaria glabrata. In the present study, three seaweed-derived halogenated sesquiterpenes, (−)-elatol, rogiolol, and obtusol are proposed as potential lead compounds for the development of anthelminthic drugs for the treatment of and pesticides for the environmental control of schistosomiasis. The three compounds were screened for their antischistosomal and molluscicidal activities. The screening revealed that rogiolol exhibits significant activity toward the survival of adult worms, and that all three compounds showed activity against S. mansoni cercariae and B. glabrata embryos. Biomonitored fractioning of L. dendroidea extracts indicated elatol as the most active compound toward cercariae larvae and snail embryos.     

Pulmonary atherosclerosis and pulmonary arterial pressure in cholesterol-fed New Zealand white rabbits.

The lung produces many vasoactive substances originating from its vascular endothelium and plays an important part in various pathose. The present study was carried out to clarify pulmonary atherosclerosis and pulmonary arterial pressure, and to elucidate a part of the pulmonary pathosis in cholesterol-fed rabbits. Atherosclerosis was induced by feeding the animals a cholesterol-rich diet. When the rabbits were fed the cholesterol-enriched diets for 15 weeks, the grade of the atherosclerosis was severer than in 8W-feeding rabbits. The lesions of 8W-feeding rabbits were mainly composed of foam cells and fibrous components, whereas in 15W-feeding rabbits, the aggregation of foam cells beneath the endothelium of the vessel was infiltrating the media and severe stenose of the lumen was observed. In the entire pulmonary arterial system, the severe obstructive vascular lesions were localized and not diffused. The pulmonary arterial pressures of the rabbits increased slightly with time and the mean pressures were 11.3+/-0.9 (control group), 11.8+/-1.0 (8W group) and 13.7+/-1.5 mmHg (15W group) respectively. A significant difference existed in the mean pressure between the control group and 15W-feeding group, but there were no significant differences in the systolic and diastolic pressures among the three groups. In conclusion, we could induce pulmonary atherosclerosis in rabbits by feeding them a hyper-cholesterol diet but not overt pulmonary hypertension.     

Globulin and albumin proteins in dehulled seeds of three Phaseolus vulgaris cultivars

Albumin and globulin fractions, obtained after modifications of the Osborne's fractionation scheme, were investigated in the seeds of three cultivars of Phaseolus vulgaris, after removal of the seed coats, to prevent interactions of tannins and phenols with the globulins. Also, by using an appropriate buffer to separate the globulins more efficiently, no cross-contaminations were observed in SDS-PAGE between these two fractions. The combination of these two procedures resulted in globulin to albumin ratios 70percnt higher than those published previously with the same cultivars. Amino acid compositions of total globulin, phaseolin and albumin fractions are presented. Whereas the albumins contained much more cysteine than the globulins, the concentrations of methionine were evenly distributed in these two fractions. Also, the bulk of methionine was found in phaseolin; cysteine was found in non-phaseolin proteins. In addition, the globulins contained unexpectedly high amounts of lysine.