Nitrous oxide emissions from soil during soybean [(Glycine max (L.) Merrill] crop phenological stages and stubbles decomposition period

The purpose of this study was to evaluate, during the phenological stages of inoculated soybean crop [Glycine max (L.) Merrill], the effect of different N fertilization levels and inoculation with Bradyrhizobium japonicum on N₂O emissions from the soil. Gas emissions were evaluated at field conditions by the static-chamber method. Nitrogen fertilization increased N₂O emissions significantly (P < 0.05). The variable that best explained cumulative N₂O emissions during the whole soybean growing season was the soil nitrate level (r ² = 0.1899; P = 0.0231). Soil moisture presented a greater control on N₂O emissions between the grain-filling period and the crop commercial maturity (r ² = 0.5361; P < 0.0001), which coincided with a positive balance of the available soil N, as a consequence of the decrease in crop requirements and root and nodular decomposition. Only soil soluble carbon (r ² = 0.29; P = 0.019) and moisture (r ² = 0.24; P = 0.039) were correlated with N₂O emissions during the residue decomposition period. The relationship between soil variables and N₂O emissions depended on crop phenological or stubbles decomposition stages.     

Edwardsiella ictaluri as the causative agent of mortality in cultured Nile tilapia

Edwardsiella ictaluri was consistently isolated from the spleens, livers, and head kidneys of diseased Nile tilapia Oreochromis niloticus from a farm experiencing mortality events in several culture ponds. We describe the first published outbreak of E. ictaluri-induced edwardsiellosis in Nile tilapia. Pure cultures of the isolated bacteria were characterized both biochemically and molecularly. Biochemical analysis was performed using the API-20E and RapID One systems, and antimicrobial susceptibility was determined by the broth microdilution method. Molecular analysis involved sequencing of the 16S rRNA gene, species-specific real-time polymerase chain reaction (PCR), and PCR-mediated genomic fingerprinting (rep-PCR). Pairwise sequence analysis of the 16S rRNA gene identified the case isolates to be a 100% match to E. ictaluri cultured from channel catfish in the southeastern United States. However, rep-PCR analysis identified the case isolates to be genetically different from representative strains isolated from disease outbreaks in cultured channel catfish in Mississippi. Infectivity challenges (intraperitoneal injection and immersion) demonstrated that a representative E. ictaluri strain isolated from tilapia was pathogenic to naive tilapia, reproducing clinical signs and mortality, thereby establishing Koch's postulates.     

Immune response to haemophilus parahaemolyticus (HP) infection in the pig I. In vitro tests to detect sensitized cells in the blood of infected and vaccinated animals

The in vitro immune response of pigs in herds infected or non-infected with H. parahaemolyticus (HP) was investigated by lymphocyte stimulation and leucocyte migration inhibition tests. The stimulation of pig lymphocytes with HP bacteria has been measured by ³H-thymidine incorporation. The response of the cells seems to be specific, lymphocytes from chronically HP-infected animals showed positive reactions with high frequency, while on the contrary, cells from SPF (specific pathogen free) animals reacted only occasionally to the HP antigens. However, in the leucocyte migration inhibition test the reactions were less specific; the widely occurring H. parasuis bacteria seem to possess antigen(s) which causes cross reactions with HP in this test.Vaccination with HP bacteria induced sensitive lymphocytes in the blood of SPF pigs and an increase of the in vitro lymphocyte reactions in already positive animals.     

Effect of oral administration of high vitamin C and E dosages on the gilthead seabream (Sparus aurata L.) innate immune system

The effect of the oral administration of high dosages of vitamins C and E on the innate immune system of the seabream was investigated. Gilthead seabream (Sparus aurata L.) were fed four different diets for 45 days: a commercial diet as control, a 3g/kg vitamin C-supplemented diet, a 1.2g/kg vitamin E-supplemented diet or a diet containing both vitamin supplements. After 15, 30 and 45 days, serum ascorbic acid and alpha-tocopherol levels, growth, complement titers and head-kidney leucocyte phagocytic and respiratory burst activities were evaluated. The results showed that serum vitamin levels reflected dietary input. Fish fed the vitamin C-supplemented diet showed an enhanced respiratory burst activity, while fish fed the vitamin E-supplemented diet exhibited increased complement and phagocytic activities. All of these positive effects were found in fish fed the joint diet, as well as a synergistically enhanced respiratory burst activity at day 30. The results demonstrate that in vivo vitamins C and E exert a synergistic effect enhancing the respiratory burst activity of seabream phagocytes.     

Sorption and thermodynamic properties of wood of <Emphasis Type="Italic">Pinus canariensis</Emphasis> C. Sm. ex DC. buried in volcanic ash during eruption

The hygroscopicity and thermodynamic properties of Pinus canariensis wood buried in volcanic ash, dating from 1100 BC, were studied and compared with recently felled juvenile and mature wood of the same species. The sorption isotherms were obtained by the saturated salt method at 35 and 50 °C. The isotherms were fitted using the Guggenheim–Anderson–de Boer model. The thermodynamic parameters were determined following the Clausius–Clapeyron integration method. To understand the behaviour of each type of wood, the chemical composition, infrared spectra and X-ray diffractograms were determined for each sample. The mature wood has a higher sugar content and lower extractive content than the juvenile and the buried wood. For both temperatures, the isotherm of the mature wood is above the isotherm of the juvenile wood and this, in turn, is above the isotherm of the buried wood, primarily influenced by the higher cellulose and hemicellulose contents and lower extractives content in the mature wood, resulting in a higher number of accessible –OH groups. Degradation of the buried wood due to high temperatures explains why its isotherms are below the isotherms of the recent wood. The energy involved in the desorption process is greater than in adsorption. Similarly, more energy is involved in the mature wood than in the juvenile wood, and the energy involved in the juvenile wood is greater than in the buried wood.     

Characterization of oral double balloon endoscopy in the dog

Exploration of the canine small intestine using conventional endoscopy is restricted to the duodenum and/or the ileum. Double balloon endoscopy (DBE) is a ‘push and pull’ technique that has been described in humans and permits a complete exploration of the small intestine. In this study, oral DBE was performed on 12 healthy dogs (10–34 kg) to characterize for the first time the efficiency, exploration dynamics and safety of the technique.DBE was successful in 83% of dogs; the average estimated insertion depth of the endoscope was 287 ± 36 cm, and the average duration of the exploration was 84 ± 8 min. No complications or relevant adverse clinical effects were observed, and there was no indication of post-procedure pancreatitis based on serology of two specific markers of pancreatitis (amylase and lipase) and the immediate nonspecific inflammatory mediator C-reactive protein. The study showed that oral DBE is viable and safe in the dog, allowing for the diagnosis and treatment of gastrointestinal diseases deep in the small intestine to an extent that has not previously been possible using conventional endoscopy.     

Paraparesis as initial manifestation of a Prototheca zopfii infection in a dog

A case of protothecosis causing non‐ambulatory paraparesis in a dog without clinical evidence of disseminated infection is described. A five‐year‐old female Labrador retriever was referred with a 10‐day history of progressive non‐ambulatory paraparesis and lumbar pain as the only physical and neurological abnormalities. Lumbar myelography revealed severe extradural spinal cord compression extending from L4 to L7 vertebrae, and a right hemilaminectomy was performed. Surgical findings included an adherent whitish hard ill‐defined mass. Cytology and biopsy results disclosed the presence of algae enclosed in a matrix of chronic inflammatory infiltrate. Culture confirmed the presence of Prototheca species. Neurological improvement occurred within a month, and the dog received antifungal treatment without evidence of clinical disseminated disease for 6 months, but died after a generalised tonic–clonic seizure. Post‐mortem examination revealed multiple foci of inflammatory granulomatous infiltrate and algae‐like structures in the brain, lumbar intumescence and cauda equina. Prototheca zopfii was identified using molecular biology methods.     

Edwardsiella ictaluri as the Causative Agent of Mortality in Cultured Nile Tilapia

Abstract

Edwardsiella ictaluri was consistently isolated from the spleens, livers, and head kidneys of diseased Nile tilapia Oreochromis niloticus from a farm experiencing mortality events in several culture ponds. We describe the first published outbreak of E. ictaluri–induced edwardsiellosis in Nile tilapia. Pure cultures of the isolated bacteria were characterized both biochemically and molecularly. Biochemical analysis was performed using the API-20E and RapID One systems, and antimicrobial susceptibility was determined by the broth microdilution method. Molecular analysis involved sequencing of the 16S rRNA gene, species-specific real-time polymerase chain reaction (PCR), and PCR-mediated genomic fingerprinting (rep-PCR). Pairwise sequence analysis of the 16S rRNA gene identified the case isolates to be a 100% match to E. ictaluri cultured from channel catfish in the southeastern United States. However, rep-PCR analysis identified the case isolates to be genetically different from representative strains isolated from disease outbreaks in cultured channel catfish in Mississippi. Infectivity challenges (intraperitoneal injection and immersion) demonstrated that a representative E. ictaluri strain isolated from tilapia was pathogenic to naïve tilapia, reproducing clinical signs and mortality, thereby establishing Koch's postulates.

Received August 30, 2011; accepted January 30, 2012     

Driving AMPA receptors into synapses by LTP and CaMKII: requirement for GluR1 and PDZ domain interaction

To elucidate mechanisms that control and execute activity-dependent synaptic plasticity, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors (AMPA-Rs) with an electrophysiological tag were expressed in rat hippocampal neurons. Long-term potentiation (LTP) or increased activity of the calcium/calmodulin-dependent protein kinase II (CaMKII) induced delivery of tagged AMPA-Rs into synapses. This effect was not diminished by mutating the CaMKII phosphorylation site on the GluR1 AMPA-R subunit, but was blocked by mutating a predicted PDZ domain interaction site. These results show that LTP and CaMKII activity drive AMPA-Rs to synapses by a mechanism that requires the association between GluR1 and a PDZ domain protein.     

Phenolic Profile and Antioxidant Capacity of Chickpeas (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) as Affected by a Dehydration Process

This study presents the effects of soaking, cooking and industrial dehydration on the phenolic profile, and antioxidant capacity in two chickpea varieties (Sinaloa and Castellano). Chromatographic analysis identified a total of 24 phenolic components, being isoflavones the main phenolics in raw and processed Sinaloa and Castellano flours. The impact of the industrial dehydration was different depending on the chickpea variety. Although Castellano chickpea exhibited the highest levels of phenolic compounds (103.1 μg/g), significant reductions were observed during processing; in contrast, the dehydration did not cause any further effects in Sinaloa flours. Interestingly, Sinaloa variety showed high thermal stability of isoflavones during processing. As expected, the levels of antioxidant capacity were in accordance with the behavior of phenolic compounds exhibiting noticeable reductions in Castellano chickpea and not relevant changes in Sinaloa chickpea. Thus, the significant occurrence of bioactive phenolic compounds along with the relevant antioxidant capacities of dehydrated chickpea flours make them to be considered functional ingredients for their beneficial health effects, especially in case of Sinaloa.