Development of an Isavirus minigenome system to study the function of the pocket RNA-binding domain of the viral nucleoprotein (NP) in salmon cells

The Isavirus is an orthomyxovirus with a genome composed of eight segments of negative single-strand RNA (−ssRNA). It has been proposed that the eight genomic segments of the Isavirus are organized as a ribonucleoprotein (RNP) complex called a minigenome, which contains all the viral RNA segments, a viral heterotrimeric polymerase and multiple copies of the viral nucleoprotein (NP). Here, we develop an Isavirus minigenome system and show the importance of the formation of active RNPs and the role of viral NP R189, R194, R302 and K325 residues in the NP RNA-binding domain in the context of RNPs. The results indicate it is possible to generate a minigenome in salmon cells, a composite ISAV RNPs with EGFP-based chimeric vRNA with heterotrimeric polymerase (PB1, PB2, PA) and NP protein using CMV-based auxiliary plasmids. It was also shown that NP R189, R194, R302 and K325 residues are important to generate viral mRNA from the constituted RNPs and a detectable reporter protein. This work is the first salmon cell-based minigenome assay for the Isavirus, which was evaluated by a bioinformatic and functional study of the NP protein in viral RNPs, which showed that correct NP-vRNA interaction is key to the functioning of RNPs.     

Increased number of large non‐atretic follicles and co‐dominance effects account for high litter sizes in Bonga sheep

To understand the ovarian basis for prolificacy of Bonga sheep, a total of 31 ewes were selected based on litter size (LS) records and divided into two groups: High Prolificacy (HP) (n = 20) with LS ≥ 2 and Low Prolificacy (LP) (n = 11) with LS = 1. At a synchronized estrus, follicular dynamics were determined using transrectal ultrasonography. Plasma estradiol concentrations were also monitored. In total 27 ewes were observed in estrus being 9/11 LP (82%) and 18/20 HP (90%). On the day of estrus (day 0), the mean number of large follicles was higher (p < .05) in HP (1.78 ± 0.19) than in LP (1.0 ± 0.28) ewes. Prior to estrus, more (p < .05) medium follicles were visible for HP compared to LP ewes. Plasma estradiol concentrations were higher in HP compared to LP ewes (18.91 ± 0.41 vs. 14.51 ± 0.65 pg/ml; p < .05) and similarly was ovulation number (2.3 ± 0.15 vs. 1.28 ± 0. 14; p < .05). Higher ovulation rates and litter size in Bonga sheep are evidenced by the previous presence of more large follicles and the existence of co‐dominance effects as most likely medium follicles are selected to ovulate.     

Increased apoptosis of CD4 and CD8 T lymphocytes in the airways of horses with recurrent airway obstruction

Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition similar to human asthma caused by exposure of susceptible horses to poorly ventilated stable environments. The disease is characterized by neutrophilic airway inflammation, mucus hypersecretion and reversible bronchoconstriction. This inflammatory process is mediated by several factors, including antibodies, cytokines, resident cells of the airway and inflammatory cellular components that arrive in the respiratory tract. An increasing body of evidence has lent support to the concept that a dysregulation of T cell apoptosis may play a central role in the development of airway inflammation and the associated asthma. Therefore, the aim of this study was to investigate early and late apoptosis of CD4 and CD8 T cell subpopulations obtained from the airways of acute RAO-positive animals after exposure to hay/straw. The percentages of CD4 and CD8 T cells and their associated frequencies of apoptosis were quantified using flow cytometry. Hay/straw exposure induced clinical airway obstruction, airway neutrophilia and increased airway mucus production in RAO-positive horses. In addition, allergen exposure increased the percentage of CD4 T cells in RAO-positive horses as well as the frequency of early and late apoptosis in both CD4 and CD8 lymphocyte subpopulations. These results suggest that the higher frequency of lymphocyte apoptosis may play a role in disease progression of horses afflicted with RAO and may partially explain the characteristic remission of this pathological condition once the allergen source is removed. However, further studies are needed to clarify the role of T cell apoptosis in RAO-affected horses.     

Phylogenetic analysis of Suid Herpesvirus 1 isolates from Argentina

Argentinean Suid Herpesvirus 1 isolates were compared with reference strains and sequences available at GenBank and phylogenetically analyzed. A short fragment of the gE gene of the immunodominant epitopes was used for preliminary grouping of isolates by phylogenetic analysis. The analysis of the partial gC gene provided more precise genetic typing and segregation into the main genotypes I and II. Results confirmed that the Argentinean genotype I isolates predominate in our country. The topology of the partial gC gene was similar to that previously reported. The Argentinean type I isolates belonged to one cluster and grouped together with NIA-3 and American and Brazilian genotype I strains. However, the results obtained by the algorithms allow inferring that the Yamagata S-81 and Mer (genotype II) strains are grouped together.     

Mechanistic model to understand in vivo salt release and perception during the consumption of dairy gels

The objective of this study was to develop a model to simulate salt release during eating. Salt release kinetics during eating was measured for four model dairy products with different dynamic salty perceptions. A simple in vivo model of salt release was developed to differentiate between the contribution of the individual and of the product to salt release. The most difficult model parameter to determine or predict is the evolution of the contact area between the product and the saliva. Fitting the model to the experimental data showed that the subject's masticatory performance and fracture initiation energy of the product determined the contact area between the product and the saliva generated by mastication. Finally, the role of release dynamics on sensory time-intensity profiles is discussed.     

Predicting risks of tornado and severe thunderstorm damage to southeastern U.S. forests

Landscape Ecology - The southeastern U.S. experiences tornadoes and severe thunderstorms that can economic and ecological damages to forest stands resulting in loss of timber, reduction in...     

Usefulness of Foliar Nitrogen-Sulfur Ratio in Spring Red Wheat

Sulfur (S) availability indicators are necessary for a rational use of fertilizers. Experiments were carried out to evaluate the sensitivity and stability of nitrogen (N):S ratio in spring red wheat. Yield responses were determined in three replications over five experimental sites. Sulfur application did not increase N concentration in plant, whereas the effect on total S concentration was varied. Results showed 25, 35, 80, and 85% correctly diagnosed samples at stages Z22, Z24, Z31, and Z39, respectively. In treatments without S limitations, a decrease in N:S ratio was observed as the crop cycle advanced. Nitrogen: S ratio differed according to the site; however, these variations tend to decrease as the crop cycle advance. In summary, for spring red wheat, N:S ratio in plant is a useful method for S deficiencies diagnostic from the end of tillering to flag leaf.     

STABILITY OF FOLIAR NITROGEN:SULFUR RATIO IN SPRING RED WHEAT AND SULFUR DILUTION CURVE

A key aspect of any sulfur (S) availability indicator is its stability throughout the crop cycle. Nine experiments were conducted with the objective to evaluate the stability of the nitrogen (N):S ratio in aerial biomass (W) in spring wheat, and to define the critical curve of S dilution. As the crop cycle progressed, a decrease (P < 0.05) in total N:S was determined. This lack of stability was explained by a lower S dilution in relation to N (P < 0.05). A decrease (P < 0.05) in N accumulation rate in relation to S was obtained as the crop cycle progressed, which points out that S accumulation in relation to N is later. A first approach was determined to the definition of the S dilution critical curve (Sc) from tillering beginning to stem elongation end (Sc = 0.37 W^?0.169; r² = 0.71 and n = 24).     

A framework for the integrated assessment and management of dredged materials in Italy: a case study based on the application of Local Sediment Quality Guidelines

Purpose

In order to assess sediment quality and to account for the great geochemical heterogeneity of Italian coasts, Local Sediment Quality Guidelines (LSQGs) have to be defined for specific portions of the coastline based on the approach developed by ICRAM–APAT (2007). This paper describes the application of LSQGs to the harbour of Fiumicino (Rome, Italy). The aims were to evaluate the quality of dredging sediments through an integrated chemical–ecotoxicological approach and to define suitable management options.

Materials and methods

Thirty-eight sediment cores, covering the planned dredging depth, were collected in the study area and sliced into 92 sediment samples. Chemical analyses, including inorganic and organic contaminants as well as microbiological parameters, were carried out for all the samples. A bioassay battery composed by the bacterium Vibrio fischeri, the sea urchin Paracentrotus lividus and the alga Dunaliella tertiolecta was applied on one third of the samples. LSQGs were derived from chemical and ecotoxicological data of the harbour area, and were integrated with those from the identified dumping site. The Baseline Chemical Level, corresponding to an absent or unlikely ecotoxicological hazard, and the Limit Chemical Level, corresponding to a probable ecotoxicological hazard, were the LSQGs derived for each chemical.

Results and discussion

A gradient of increasing contamination, moving inland due to urban and agricultural effluents, was observed. Ecotoxicological analyses, similar to microbiological ones, confirmed the poor sediment quality, with the exception of a sample located at the port entrance, where hydrodynamics flush sediment away from the site. Principal component analysis allowed a clear discrimination of three areas, each affected by a different contamination degree and influenced by many sources related to industrial, commercial and/or urban activities. Using LSQGs and the results of bioassays, it was possible to classify the sediment quality of the whole harbour area and to define the most suitable management options. It was found that Fiumicino harbour sediment was not suitable for either beach nourishment or for offshore dumping, with the exception of a negligible amount located at the port entrance. In turn, most sediment seemed to be suitable for disposal in a properly sealed confined disposal facility or for mechanical/chemical treatment.

Conclusions

This case study provided useful insights for implementing the development of LSQGs for more realistic sediment management and will assist in promoting its application to harbour dredging at the local level.