Molecular cloning, expression and first antigenic characterization of human astrovirus VP26 structural protein and a C-terminal deleted form

The open reading frame 2 (ORF2) of human astrovirus (HAstV) encodes the structural VP26 protein that seems to be the main antigenic viral protein. However, its functional role remains unclear. Bioinformatic predictions revealed that VP29 and VP26 proteins could be involved in virus-cell interaction. In this study, we describe for the first time the cloning and expression in Escherichia coli (E. coli) of a recombinant VP26 (rVP26) protein and a VP26 C-terminal truncated form (VP26 Delta C), followed by purification by NTA-Ni(2+) agarose affinity chromatography. Protein expression and purification were evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot (WB). Then, the purified proteins were evaluated for antigenic properties in enzyme linked immunosorbent assay (ELISA) using a polyclonal antibody (PAb) and a neutralizing monoclonal antibody (nMAb) named PL2, both of them directed to HAstV. The results presented herein indicate that the C-terminal end of the VP26 protein is essential to maintain the neutralizing epitope recognized by nMAb PL2 and that the N-terminus of VP26 protein may contain antigenic lineal-epitopes recognized by PAb. Thus, these recombinant proteins can be ideal tools for further antigenic, biochemical, structural and functional VP26 protein characterization, in order to evaluate its potential role in immunodiagnosis and vaccine studies.     

1-Methyl cyclopropene extends postharvest life of spinach leaves

Senescence of detached spinach leaves either untreated or treated with 0.1 or 1.0 μL L^?1 1-MCP has been investigated. 1-MCP treated leaves had higher chlorophyll content and photosystem II potential quantum yield (Fv/Fm) and lower solute leakage than untreated leaves after storage in darkness at 23 °C for 6 d, indicating a delay of senescence. Ethylene production was increased in spinach supplemented with 1-MCP after 3 d storage and then declined to the rates of untreated leaves. 1-MCP treated spinach had higher ascorbic acid and glutathione concentrations, and a low oxidised/reduced ratio for both antioxidants. Accumulations of ammonium and protein degradation were reduced by 1-MCP. The results presented here indicate that inhibition of ethylene sensitivity can be successfully used to extend the postharvest life of spinach leaves.     

Exploring the recent upsurge in productivity disparities among European regions

This paper analyses thse evolution of productivity disparities across 156 European regions in the period 2000–2015. Using regional data, a battery of inequality indexes enables us to assess the extent of regional disparities. After confirming that labour productivity is the main component of income disparities, a dynamic shift-share analysis is carried out at a 10-industry level of disaggregation. The study evaluates the relative role of the three components underlying the disparities in regional productivity: changes in the industry mix, and within- and between-industry productivity gaps. The main results can be summarised as follows. First, regional disparities are on the rise again in the EU. Second, most regions are now closer to the average, while a small group of the richest regions are moving further away. Third, the main drivers of productivity disparities are within-industry differences in labour productivity with regard to the richest regions and, less importantly, the specialisation of the richest regions in more progressive industries. Finally, the net effect of structural change is still making a positive contribution to convergence with the leading regions.     

Efficacy of Fe(o,o-EDDHA) and Fe(o,p-EDDHA) isomers in supplying Fe to strategy I plants differs in nutrient solution and calcareous soil

The FeEDDHA [iron(3+) ethylenediamine di(o-hydroxyphenylacetic) acid] is one of the most efficient iron chelates employed in the correction of iron clorosis in calcareous soils. FeEDDHA presents different positional isomers: the ortho-ortho (o,o), the ortho-para (o,p), and the para-para (p,p). Of these isomers, the p,p cannot chelate Fe in soil solution in a wide range of pH values, while both o,o and o,p can. The objective of this work was to compare the efficiency of both isomers (o,o and o,p) to provide Fe to two Strategy I plants (tomato and peach) in nutrient solution (pH approximately 6.0), as well as in calcareous soil (pH approximately 8.4; CALCIXEREPT). For this, chelates of both o,o-EDDHA and o,p-EDDHA with 57Fe (a nonradioactive isotope of Fe) were used, where the 57Fe acts as a tracer. The results obtained showed that the o,o isomer is capable of providing sufficient Fe to plants in both nutrient solution and calcareous soil. However, the o,p isomer is capable of providing sufficient Fe to plants in nutrient solution but not in calcareous soil.     

Enzymatic and fungal treatments on sugarcane bagasse for the production of mechanical pulps

Crude ligninolytic enzyme extracts from Phanerochaete chrysosporium fungi were applied to sugarcane bagasse, prior to thermomechanical (TMP) and chemithermomechanical pulping (CTMP), and their properties were compared with the normal TMP and CTMP and also with TMP and CTMP pretreated with Ceriporiopsis subvermispora and P. chrysosporium fungi. The sugarcane bagasse was impregnated with the crude enzyme extract containing lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac). The results show that pretreatment with enzyme crude extract is an advantageous way to produce TMP and CTMP from sugarcane bagasse, as compared with only fungal pretreatment. Enzymatic pretreatments need only hours to enhance pulping and paper properties, compared with the weeks necessary for fungal treatments. Higher pulp yields were obtained compared with the fungal pretreatments. Enzymatic pretreatment reduced the energy consumption in a proportion similar to that of C. subvermispora fungal pretreatment and increased the pulp tensile index compared with the normal TMP and CTMP pulps, although the tensile strength was somewhat lower than that for pulps from C. subvermispora fungal pretreatment before CTMP processing. An advantage of enzymatic pretreatment is that brightness is increased compared with normal TMP and CTMP processes, whereas fungal pretreatments reduce the brightness.     

Population declines of a long-lived salamander: a 20+-year study of hellbenders, Cryptobranchus alleganiensis

Accurate assessment of whether long-lived species are stable or declining is challenging. Life history characteristics such as delayed maturity result in relatively slow population responses to perturbations, so data should be collected across a relatively long time span. Because differential effects on age classes can be important, studies should also examine potential changes in the population's age structure. Moreover, multiple populations should be studied to indicate whether changes are regional or are restricted to local populations. We incorporated all three factors (long duration, multiple populations, age structure data) into our study of the conservation status of a long-lived aquatic salamander, the hellbender, Cryptobranchus alleganiensis. Over the 20+ years of this study, populations of hellbenders declined by an average of about 77%. This decline was characterized by a shift in size (age) structure, with a disproportionate decrease in numbers of young individuals. The change in density and age structure was consistent for populations in five rivers and for two subspecies (C. a. alleganiensis and C. a. bishopi), indicating that the decline is not restricted to one or two local populations. For the population with the most extensive data, the decline had clearly begun by the 1980s and there was a significant decrease in body condition over the period of the study. It is not known whether population declines for hellbenders have a single cause or whether each population has experienced independent declines.     

Effects of a dairy product fortified with multiple micronutrients and omega-3 fatty acids on birth weight and gestation duration in pregnant Chilean women

OBJECTIVE: To test the hypothesis that maternal food fortification with omega-3 fatty acids and multiple micronutrients increases birth weight and gestation duration, as primary outcomes. DESIGN: Non-blinded, randomised controlled study. SETTING: Pregnant women received powdered milk during their health check-ups at 19 antenatal clinics and delivered at two maternity hospitals in Santiago, Chile. SUBJECT: Pregnant women were assigned to receive regular powdered milk (n = 477) or a milk product fortified with multiple micronutrients and omega-3 fatty acids (n = 495). RESULTS: Intention-to-treat analysis showed that mean birth weight was higher in the intervention group than in controls (65.4 g difference, 95% confidence interval (CI) 5-126 g; P = 0.03) and the incidence of very preterm birth (0.80 just for mean birth weight and birth length in the on-treatment analysis; birth length in that analysis had a difference of 0.57 cm (95% CI 0.19-0.96 cm; P = 0.003). CONCLUSIONS: The new intervention resulted in increased mean birth weight. Associations with gestation duration and most secondary outcomes need a larger sample size for confirmation.     

Characterization of the reconstructed 1918 Spanish influenza pandemic virus

The pandemic influenza virus of 1918-1919 killed an estimated 20 to 50 million people worldwide. With the recent availability of the complete 1918 influenza virus coding sequence, we used reverse genetics to generate an influenza virus bearing all eight gene segments of the pandemic virus to study the properties associated with its extraordinary virulence. In stark contrast to contemporary human influenza H1N1 viruses, the 1918 pandemic virus had the ability to replicate in the absence of trypsin, caused death in mice and embryonated chicken eggs, and displayed a high-growth phenotype in human bronchial epithelial cells. Moreover, the coordinated expression of the 1918 virus genes most certainly confers the unique high-virulence phenotype observed with this pandemic virus.     

Effect of the photoperiod on the larval development,body growth and muscle cellularity of shi drum (Umbrina cirrosa L.)

Shi drum (Umbrina cirrosa L.) larvae were maintained under three photoperiod regimes: a natural photoperiod regime (16L:8D), continuous light (24L) and equal durations of light and dark (12L:12D) from the end of the vitelline phase to the end of the metamorphosis. Muscle and body parameters were studied at hatching and at 4, 10, 14, 39 and 55 days post hatching (dph). During the vitelline phase, the total body length growth was scarce, whereas the muscle grew significantly, being the hypertrophy of the main mechanism involved. Both the total body length and the hypertrophy were significantly greater at 16L:8D than in the rest of photoperiod regimes. At 10 and 14 dph, the greatest body length was reached at 16L:8D, followed by the 24L group, showing the 12L:12D group the lowest values. At 14 dph, the hypertrophy and hyperplasia were also higher at 16L:8D than in the rest of groups. At 39 dph, the highest values of body length were reached in both 16L:8D and 12L:12D regimes, this latter group reaching the highest values of hypertrophy, thus showing a compensatory growth when comparing with the previous stages. The end of the metamorphosis took place at 50–55 dph in all the groups, with 2.7–3.1 cm of body length (P > 0.05). At this stage, the transverse area of the white muscle was similar among the groups, but the greatest hypertrophy was reached at 16L:8D, whereas the highest hyperplasia was reached at 24L.     

Tolerance to Formalin by a Fluidized-Bed Biofilter and Rainbow Trout Oncorhynchus mykiss in a Recirculating Culture System

Formalin tolerances of a fluidized-bed sand biofilter and rainbow trout Oncorhynchus mykiss were tested in a semi-closed freshwater recirculating culture system. Progressively higher formalin levels were tested until fish mortality (±1.9%) occurred. A 1-h exposure to 167 ppm formalin, followed by flushing, was safe for trout (no mortality) at 15.0 C but not at 16.5 C. A 110-ppm indefinite treatment (no flushing) was safe at 17.3 C, but 120 ppm at 17.3 C and 100 ppm at 17.8 C were not. Biofilter nitrification was not impaired by 1-h formdin treatments up to 167 ppm at 16.5 C, and not, usually, by indefinite treatments up to 120 ppm at 17.3 C. However, a find indefinite treatment of 70 ppm was followed by abnormally high nitrite levels for 9 d. Formaldehyde remained detectable in the system for 11 h during indefinite treatment at 120 ppm formalin. Tests on the system's Co₂ stripper did not indicate that it removed formaldehyde.