Deposition of gold mining tailings in tropical soils: metal pollution and toxicity to earthworms

Journal of Soils and Sediments - This study consists of the evaluation of metals acute toxicity levels taking into consideration a hypothetic scenario of dam breaking and land deposition of two...     

Spray-drying Microencapsulation of an Extract from Tilia tomentosa Moench Flowers: Physicochemical Characterization and in Vitro Intestinal Activity

Plant Foods for Human Nutrition - Silver linden (Tilia tomentosa Moench, TtM) flowers possess several health-promoting properties, especially at the neurological level, such as intestinal...     

Administration of Probiotic Strain to Improve Sea Bream Wellness during Development

Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult sea bream (Sparus aurata) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously, during sea bream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. The probiotic treatment influenced gut colonization: at 35 days post-hatching (p.h.) L. fructivorans was not present in the gut, but the treatment induced colonization by L. plantarum. At 66 days p.h., L. fructivorans was evident also in the control; moreover, when suitable environmental conditions appeared in the post-metamorphosis gastro-intestinal tract, competition between L. plantarum and L. fructivorans occurred. At 90 days p.h., L. plantarum was displaced by L. fructivorans that became significantly higher with respect to the control. In treated groups, probiotic administration significantly decreased larvae and fry mortality.     

Biological and Artificial Matrixes as PAH Accumulators: An Experimental Comparative Study

In order to find out a new effective accumulator of polycyclic aromatic hydrocarbons (PAHs) useful for monitoring studies on a large scale and low costs, the accumulation capacity of both biological and artificial matrixes (mosses and polyester fibers, respectively) has been tested. For this purposes, Hypnum cupressiforme and dacron® were exposed to pollution airborne in two sites located nearby an active iron industry and in center of the town of Trieste, where high PAH pollution spots, due to vehicular traffic, are usually detected. The samplers were exposed in six sampling sessions for 21 days. The results obtained were compared with data collected by active PAH samplers, usually employed for official widespread monitoring. The level of correlation between the data sets was calculated. Furthermore, a repeatability study of data was performed. According to the results, both matrixes are good PAH accumulators, though they show different skills.     

Studies on the Nutrition of Spotted Sand Bass Paralabrax maculatofasciatus: Effect of the Dietary Protein Level on Growth and Protein Utilization in Juveniles Fed Semipurified Diets

Two feeding trials were conducted to determine the digestibility of a casein-based semi-purified diet and the effects of different protein levels on growth and protein use of spotted sand bass Paralabrax maculatofasciatus juveniles. For trial I, a semipurified diet with vitamin-free casein as the sole source of protein was fed three times a day to apparent satiation, for a period of 20 d. Feces were collected by siphoning each tank. The digestibility of the experimental diet was high: 97% for protein, 89% for lipids, and 84% for gross energy, whereas that of organic matter was 78%. For trial II, seven diets were formulated using vitamin-free casein at graded levels (25, 30, 35, 40, 45, 50, and 55% protein). Triplicate tanks for each dietary treatment were stocked with fish and fed by hand three times a day to apparent satiation for 6 wk. Perfomance of fish fed the different diets was evaluated for survival, percent weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio. Survival was 100% for all treatments. Growth of spotted sand bass juveniles increased as the dietary protein increased, but no evidence of reaching a plateau was found. The daily feed intake values showed an inverse relation to the protein content of the diets. The feed conversion ratio did not differ among diets containing 40% protein or greater. The results indicate that spotted sand bass juveniles with 2.5-g mean weight need at least 55% dietary protein for best growth when casein is the sole protein source. However, in terms of feed conversion ratio, the requirement apparently could be lower.     

A Conus regularis Conotoxin with a Novel Eight-Cysteine Framework Inhibits CaV2.2 Channels and Displays an Anti-Nociceptive Activity

A novel peptide, RsXXIVA, was isolated from the venom duct of Conus regularis, a worm-hunting species collected in the Sea of Cortez, México. Its primary structure was determined by mass spectrometry and confirmed by automated Edman degradation. This conotoxin contains 40 amino acids and exhibits a novel arrangement of eight cysteine residues (C-C-C-C-CC-CC). Surprisingly, two loops of the novel peptide are highly identical to the amino acids sequence of ω-MVIIA. The total length and disulfide pairing of both peptides are quite different, although the two most important residues for the described function of ω-MVIIA (Lys2 and Tyr13) are also present in the peptide reported here. Electrophysiological analysis using superior cervical ganglion (SCG) neurons indicates that RsXXIVA inhibits Ca_V2.2 channel current in a dose-dependent manner with an EC₅₀ of 2.8 μM, whose effect is partially reversed after washing. Furthermore, RsXXIVA was tested in hot-plate assays to measure the potential anti-nociceptive effect to an acute thermal stimulus, showing an analgesic effect in acute thermal pain at 30 and 45 min post-injection. Also, the toxin shows an anti-nociceptive effect in a formalin chronic pain test. However, the low affinity for Ca_V2.2 suggests that the primary target of the peptide could be different from that of ω-MVIIA.     

A novel mutation of the CLCN1 gene associated with myotonia hereditaria in an Australian cattle dog

BACKGROUND: Heritable myotonia is a genetic muscle disorder characterized by slow relaxation of skeletal muscles. The main clinical signs are skeletal muscle stiffness, especially after vigorous contraction, and muscle hypertrophy. Muscle stiffness may be enhanced by inactivity, and often is relieved by exercise. Myotonia can be inherited in an autosomal dominant or recessive manner (Thomsen- or Becker-type myotonia, respectively). In mice, goats, Miniature Schnauzer dogs, and most affected humans, the disorder is caused by mutations in CLCN1, which encodes the skeletal muscle voltage-gated chloride channel, Cl1C-1. HYPOTHESIS: We hypothesized that an Australian Cattle Dog with generalized muscle stiffness and hypertrophy examined at the Ontario Veterinary College would have a mutation in the CLCN1 gene. ANIMALS: A pure-bred Australian Cattle Dog from Ontario, Canada, was used. METHODS: Based on clinical signs and electromyographic test results, a diagnosis of myotonia hereditaria was made, and a muscle biopsy was collected for genetic analysis. RESULTS: Sequence data obtained from the affected dog confirmed that it was homozygous for a single base insertion in the CLCN1 coding sequence. This mutation would result in a truncated ClC-1 protein being expressed, which, based on molecular evidence from other studies, would result in functionally compromised chloride conduction in the skeletal muscles of the animal. CONCLUSIONS AND CLINICAL IMPORTANCE: To the authors' knowledge, this report describes the Ist case of myotonia in an Australian Cattle Dog and represents the 1st non-Schnauzer canine myotonia to be genetically characterized. In addition, we developed a polymerase chain reaction-based genetic screen to detect heterozygotes with this mutation in the at-large Australian Cattle Dog population.     

A practical and reliable procedure for in vitro induction of tetraploid tomato

A relatively rapid, practical and reliable procedure for in vitro production of tetraploid tomato using colchicine is described. Using this procedure 11.11% generation of tetraploids was obtained after exposure of seedling shoot meristem explants with 8 mM colchicine for 96 h. Confirmation of tetraploid production (2n = 48), was determined by flow cytometry and verified by cytogenetic analysis of root tip preparations. The results indicate that the procedure is adequate for induction and screening of tetraploid tomato plantlets.     

Shedding light on the migratory patterns of the Amazonian goliath catfish,Brachyplatystoma platynemum,using otolith 87Sr/86Sr analyses

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Iron oxide‐humic acid coprecipitates as iron source for cucumber plants

In soil, iron (Fe) solubility depends on complex interactions between Fe minerals and organic matter, but very little is known about plant availability of Fe present in Fe oxides associated with humic substances. For this purpose, this study investigates the effect of Fe mineral crystallinity in the presence of humic acids (HA) on Fe availability to plants. Four Fe–HA mineral coprecipitates were prepared, either in the presence or absence of oxygen, i.e., two goethite (G)‐HA samples containing large amounts of Fe as nanocrystalline goethite and ferrihydrite mixed phases, and two magnetite (M)‐HA samples containing crystalline magnetite. Bioavailability studies were conducted in hydroponic systems on cucumber plants (Cucumis sativus L.) grown under Fe deficient conditions and supplied with the Fe–HA coprecipitates containing goethite or magnetite. Results showed that plants grown in the presence of Fe–HA coprecipitates exhibited a complete recovery from Fe deficiency, albeit less efficiently than plants resupplied with Fe‐chelate fertilizer used as control (Fe‐diethylene triamine penta acetic acid, Fe‐DTPA). However, the supply with either G‐ or M–HA coprecipitates produced different effects on plants: G–HA‐treated plants showed a higher Fe content in leaves, while M–HA‐treated plants displayed a higher leaf biomass and SPAD (Soil–Plant Analysis Development) index recovery, as compared to Fe‐DTPA. The distribution of macronutrients in the leaves, as imaged by micro X‐ray fluorescence (µXRF) spectroscopy, was different in G–HA and M–HA‐treated plants. In particular, plants supplied with the poorly crystalline G–HA coprecipitate with a lower Fe/HA ratio showed features more similar to those of fully recovered plants (supplied with Fe‐DTPA). These results highlight the importance of mineral crystallinity of Fe–HA coprecipitates on Fe bioavailability and Fe uptake in hydroponic experiments. In addition, the present data demonstrate that cucumber plants can efficiently mobilize Fe, even from goethite and ferrihydrite mixed phases and magnetite, which are usually considered unavailable for plant nutrition.