Assessing and predicting granular‐materials hydrophobicity by parametrizing a general equation of state§

Wettability is related to forces or surface tensions (σ) acting at the solid–liquid–vapor interface. Given that surface tensions are difficult to assess directly, contact angles (CA) are used as indicators of the balance of forces acting in the system. In this context, the ES theory was developed as an alternative to assess the σ parameters of the Young's equation. This research evaluates the applicability of a proposed equation of state (ES), which is in theory also able to predict the CA of a sample when two σ parameters of the Young's equation and two fitting parameters (β and α) of the function Φ = (σ_SL) are known (Φ: molecular interaction parameter, σ_SL: solid–liquid surface tension). These parameters were determined by different experimental methods assessing the CA, in order to determine which method is more suitable to validate the ES theory: Capillary Rise Method (CRM) and Wilhelmy Plate Method (WPM). For WPM, two modes (advancing and equilibrium CA) were applied. Finally, results of CA between the experimental measurements obtained by WPM and those predicted by the ES were compared. Samples of coarse silt, fine sand, and nonporous glass beads with different levels of water repellency were used as test materials. In line with previous research, all methods showed lower values of σ for samples with increasing hydrophobicity. At the same time, Φ reduces consistently with higher hydrophobicity, up to ≈ 0.5–0.6 based on CRM and WPM‐ECA data, and even lower (≈ 0.1–0.2) in WPM‐ACA. α increased with higher hydrophobicity, having relatively stable values in samples having σ_SV > 40 mN m^–1. β showed stable values for samples having σ_SV > 35–40 mN m^–1. In hydrophobic samples (σ_SV < 35 mN m^–1), β decreased in calculations based on WPM‐ACA data, and to a minor degree in WPM‐ECA. The agreement between the CA directly measured (WPM) and those predicted by the ES was low, although better for the WPM‐ECA, suggesting that this last approach can be considered more suitable to evaluate the ES theory.     

Abrupt temperature changes in the Western Mediterranean over the past 250,000 years

A continuous high-resolution Western Mediterranean sea surface temperature (SST) alkenone record spanning the past 250,000 years shows that abrupt changes were more common at warming than at cooling. During marine isotope stage (MIS) 6, SST oscillated following a stadial-interstadial pattern but at lower intensities and rates of change than in the Dansgaard/Oeschger events of MIS 3. Some of the most prominent events occurred over MISs 5 and 7, after prolonged warm periods of high stability. Climate during the whole period was predominantly maintained in interglacial-interstadial conditions, whereas the duration of stadials was much shorter.     

Insertion and stable expression of Gaussia luciferase gene by the genome of bovine viral diarrhea virus

As a tool to address selected issues of virus biology, we constructed a recombinant cDNA clone of bovine viral diarrhea virus (BVDV) expressing Gaussia luciferase (Gluc) reporter gene. A full-length genomic cDNA clone of a non-cytopathic BVDV isolate was assembled by recombination in yeast Saccharomyces cerevisiae. The Gluc gene was inserted between the N^pro and Core protein coding regions by recombination. The cDNA transcribed in vitro was infectious upon transfection of MDBK cells, resulting in reporter gene expression and productive virus replication. The rescued viruses were stable for 15 passages in cell culture, maintaining the replication kinetics, focus size and morphology similar to those of the parental virus. Expression and correct processing of the reporter protein were also maintained, as demonstrated by Gluc activity. These results demonstrate that genes up to 555 bp are simply assembled by a single step in yeast recombination and are stably expressed by this cDNA clone.     

Differences between acceleromyography and electromyography during neuromuscular function monitoring in anesthetized Beagle dogs

ObjectiveQuantitative neuromuscular monitoring is essential for studies of potency and duration of neuromuscular blocking agents, and for detecting residual paralysis in anesthetized patients. This investigation evaluates whether there are systematic differences between acceleromyography (AMG) and electromyography (EMG); two quantitative methods for monitoring neuromuscular block.Study designProspective.AnimalsTen healthy Beagle dogs.MethodsDogs were anesthetized with isoflurane and dexmedetomidine. Both ulnar nerves were stimulated with a train-of-four (TOF) pattern every 15 seconds. The magnitude of the first twitch (T1) and the TOF ratio (magnitude of T4/T1; TOFR) were quantified simultaneously with AMG and EMG, applied randomly to each extremity. The extent of maximal block (T1 depression) and onset time were measured by AMG and EMG during TOF monitoring after the administration of cisatracurium (0.05 mg kg⁻¹). In addition, recovery of T1 to 25% and 75%, the recovery index (time between T1 of 25% and 75%), and recovery of the TOFR to 0.9 were used to characterize recovery from cisatracurium and were compared between monitors. Regression and Bland-Altman plots for T1 and TOFR were also created.ResultsMaximal block and onset time were not different between monitors. Time to recovery of T1 to 25% and 75%, and time to TOF ratio 0.9 was significantly shorter with AMG. The recovery index was not different between monitors. When the TOFR returned to 0.9 with AMG, EMG still measured considerable residual block (TOFR 0.47).Conclusions and clinical relevanceElectromyography consistently detected residual NMB when recovery from NMB was complete as assessed by AMG.     

Bacteriological water quality of recirculating aquatic systems for maintenance of yellowtail amberjack Seriola lalandi

The bacteriological water quality associated with marine fish farming systems can be a determining factor in the development of disease, and understanding this quality is fundamental for the prevention and control of possible disease outbreaks. In the present study, the bacteriological water quality of a yellowtail amberjack Seriola lalandi broodstock maintenance system, composed of two units of a recirculation aquaculture system (RAS 1 and RAS 2), was determined. From February 2016 to January 2017, monthly samples of surface water were taken at six points in the two RAS systems: (a) from the water reception tank and (b) from filter 1 and (c) tank 1 (in RAS 1) and (d) filter 2 and (e) tank 2 (in RAS 2) and from a joint (f) discharge point. The bacteriological quality was determined by counting total heterotrophic bacteria (THB) and by molecular identification (16S rRNA gene). The number of THB showed a tendency to decrease in filters 1 and 2, to increase in tanks 1 and 2, and again increase in the discharge. The fluctuation of THB, in general, was from 1.0 × 10³ to 2.9 × 10⁵ CFU/mL. In total, 102 colonies were isolated, corresponding to nine orders and 52 species, and Vibrionales and Alteromonadales were the most abundant orders. The bacterium Vibrio harveyi, a pathogen of S. lalandi, was identified, as were other bacterial species that are known pathogens; however, no signs of disease or mortality events were recorded during the study. These results suggest that the bacterial community contributed to the maintenance of a balance in the RAS, which prevented the development of infectious diseases. Furthermore, the physicochemical parameters (temperature, oxygen, nitrogen compounds, and alkalinity) were maintained within the optimum range required by S. lalandi. Some zoonotic bacteria were found, as well as bacteria with probiotic and industrial uses. These results represent the first report on bacteriological quality in RAS for S. lalandi.     

Effects of Wheat Starch and Gluten on Tortilla Texture

Wheat starches were isolated from three wheat flours. Two vital wheat glutens, one from a commercial source and another one isolated from straight-grade flour, were combined with wheat starches to form reconstituted flours with a protein level of 10%. Several characteristics of tortillas made with the hot-press method were measured. No significant difference (P < 0.05) occurred in texture of tortillas made with hard wheat gluten and soft wheat gluten. Wheat starches did not have any significant (P < 0.05) effect on tortilla stretchability or foldability. Analysis of variance confirmed that wheat starch and gluten had limited effects on tortilla texture. The possible reasons were that the solubles of wheat flour were not included, and the shortening in the tortilla formula interfered with the interaction of gluten and starch.     

Composition of Functional Lipids in Hulled and Hulless Barley in Fractions Obtained by Scarification and in Barley Oil

Two cultivars of hulled barley (Thoroughbred and Nomini) and two cultivars of hulless barley (Doyce and Merlin) were scarified to abrade the outer layers of hull and pericarp. The resulting scarification fines fractions were evaluated as potential sources of functional lipids (phyto‐sterols, tocopherols, and tocotrienols). The levels of total phytosterols and total tocotrienols in the barley scarification fine fractions were probably not high enough to justify their use as functional foods. However, the levels of total phytosterols and total tocotrienols in the oils extracted from both whole kernels and scarified fines were both sufficiently high to make it reasonable to consider their potential use as new functional oils. Indeed, the levels of total tocotrienols in barley oils (2,911–6,126 mg/kg of oil) are several‐fold higher than those reported in two other oils that are being marketed as high in tocotrienols: palm oil (530 mg/kg) and rice bran oil (770 mg/kg). The levels of total phytosterols in barley oils range from 1.20 to 9.60 g/100 g of oil.