Evaluating the distribution of African swine fever virus within a feed mill environment following manufacture of inoculated feed

It is critical to understand the role feed manufacturing may have regarding potential African swine fever virus (ASFV) transmission, especially given the evidence that feed and/or ingredients may be potential vectors. The objective of the study was to evaluate the distribution of ASFV in a feed mill following manufacture of contaminated feed. To accomplish this, a pilot-scale feed mill consisting of a mixer, bucket elevator, and spouting was constructed in a BSL-3Ag facility. First, a batch of ASFV-free feed was manufactured, followed by a batch of feed that had an ASFV-contaminated ingredient added to feed, which was then mixed and discharged from the equipment. Subsequently, four additional ASFV-free batches of feed were manufactured using the same equipment. Environmental swabs from 18 locations within the BSL-3Ag room were collected after each batch of feed was discharged. The locations of the swabs were categorized into four zones: 1) feed contact surface, 2) non-feed contact surface < 1 meter away from feed, 3) non-feed contact surface > 1 meter from feed, and 4) transient surfaces. Environmental swabs were analyzed using a qPCR specific for the ASFV p72 gene and reported as genomic copy number (CN)/mL of environmental swab processing buffer. Genomic copies were transformed with a log10 function for statistical analysis. There was no evidence of a zone × batch interaction for log10 genomic CN/mL (P = 0.625) or cycle threshold (Ct) value (P = 0.608). Sampling zone impacted the log10 p72 genomic CN/mL (P < 0.0001) and Ct values (P < 0.0001), with a greater amount of viral genome detected on transient surfaces compared to other surfaces (P < 0.05). This study illustrates that once ASFV enters the feed mill environment it becomes widespread and movement of people can significantly contribute to the spread of ASFV in a feed mill environment.

The Flow Field, Particle Distribution, and Determination of the Optimal Sampling Area around Aircraft

Particle trajectories around an aircraft will change during a flight; therefore, analyzing particle distribution around the aircraft is necessary to accurately sample aerosols. Both computational fluid dynamics (CFD) simulations and wind tunnel experiments are employed to optimize the sampling zones around an aircraft. The wind tunnel model is the Harbin Y-12, similar to the Twin Otter and King Air. The aircraft head is taken as the coordinate original point. The coordinate X is parallel to the wings, the coordinate Y is parallel to the fuselage, and the coordinate Z is perpendicular to the fuselage. The results show that the closer the distance to the central line for the X direction is, the greater the velocity error is. A suitable position for sampling is under the fuselage because of low turbulence, convenient connection pipelines, and safety considerations. The shadow and enhancement zone area thicknesses gradually increase with increasing particle size. The shadow zone thickness under the fuselage is approximately 20, 70, 110, and 350 mm for particle sizes of 1, 10, 20, and 50 μm, respectively. The greater the distance from the aircraft head for the Y direction is, the smaller the velocity error is. The attack angle has no obvious effect on the flow speed at different positions. The CFD simulation results are in basic agreement with the wind tunnel experiment results. The optimal sampling zone is approximately 2300–6500 mm for the Y direction for the aircraft head, 250–500 mm for the X direction for the aircraft head, and 490–600 mm for the Z direction under the fuselage of aircraft.

Spatial variation of valuable bacterial enzymes in soil: A case study from different agro ecological zones of West Bengal, India

The spatial variability of cellulase, amylase, protease and pectinase activities were evaluated from four zones of West Bengal, India. The enzyme production data was plotted on the map of the study areas and spatial variability of cellulase, amylase, protease and pectinase activity was obtained. Available nitrogen of the soil was the most variable parameter with changing enzyme activity. It also varied with the available phosphorus but the variation was least with organic carbon content of the soil. Amylase was correlated with pectinase, available nitrogen and phosphorus. Cellulase was correlated with only available nitrogen; protease was correlated with pectinase and Pectinase was correlated with available nitrogen of the soil of the four sampling zone. Except protease activity, other enzymes were significantly correlated with bacterial density of the soil. These findings ultimately develop relationship among soil major nutrients and the map can be used for future enzyme bioprospecting in West Bengal, India.

Changes in the juvenile fish assemblage of a Mediterranean shallow Posidonia oceanica seagrass nursery area after half century

The within-year dynamics of the juvenile fish community over a shallow nursery seagrass-dominated habitat (Posidonia oceanica) in a Mediterranean Bay was compared between two surveys separated 50 years (1960 and 2012-2013). A nocturnal survey over depths ranging from 2 to 10 m over patched seagrass meadows was conducted for one year (2012-2013) through 72 epibenthic tows spread fortnightly in 4 close-by stations, mimicking a survey, conducted in 1960, in terms of sampling intensity, sampling zone, temporal coverage and sampling gear. Although a large proportion of fish species was similar among surveys, remarkable and statistically significant differences were detected. A striking feature was that one of the most common and abundant sparidae species nowadays, Diplodus annularis, did not appear in 1960. Other strong differences included the disappearance of European eel Anguilla anguilla in the recent survey. Further, one of the most valuable species for artisanal fisheries in the area, the black scorpionfish Scorpaena porcus, was almost 10 times less abundant in 1960. A finer-scale study of the 2012-2013 survey allowed a quantitative analysis between species composition and potential environmental drivers through Redundancy Analysis that described well the current pattern of time-dependent recruitment pulses in nearshore meadows from the area through a year, with marked effects of surface temperature and photoperiod. The comparison between surveys suggests that some strong differences between surveys are unlikely attributable to interannual stochasticity in recruitment or environmental variability but may be related with i) unaccounted for habitat transformation and/or ii) the strong decrease of juvenile fishing mortality in this shallow nursery area since the enforcement of bans on littoral epibenthic trawling activities characteristic of this area.

Ontogenetic and intraspecific variability in otolith shape of anchoveta (Engraulis ringens) used to identify demographic units in the Pacific Southeast off Chile

The phenotypical variability in otolith shape of anchoveta (Engraulis ringens) was analysed in three zones (I, II and III) from north to south along the Chilean coast, using juvenile and adult fish. Generalised additive models were used to analyse shape indices and canonical discriminant analysis was used to analyse elliptical Fourier harmonics. The form factor and ellipticity indices varied significantly among the three zones, whereas roundness, circularity and rectangularity indices only showed differences between Zones I and III. Fourier reconstructed outlines for five ontogenetic stages suggested important differences among sampling zones, which were larger for sampling Zone III, where, at the same fish length, otoliths were smaller than those sampled in Zones I and II, at least at the pre-recruit stage. Elliptical Fourier descriptors showed significant differences among the three units, with a total percentage of correct classifications for juveniles of 89 and 74% for raw data and cross-validated cases respectively, compared with &gt;85 and ~65% respectively for adult fish. The results support the hypothesis that juveniles and adults of anchoveta have remained segregated throughout their entire, or at least a fraction of, their life cycle, mainly between the extreme northward and southward zones.

EVALUATION OF THE INFLUENCE OF THE TIDES ON THE PHYSICALCHEMICAL PARAMETERS PRESENT IN THE WATERS OF THE GUARAGUAÇU RIVER - PR

The GuaraguaçU River is an important Paranaense coastal ecosystem. As this water body approaches the mouth of the river, fresh water is gradually mixed with the salt water of the ocean by the action of the tidal cycle, thus characterizing the estuarine environment. In this study gravimetric tests were carried out to determine the concentration of total solids dissolved in the samples of said river. These values were compared with those of electrical conductivity and the salinity of the samples. Sixteen samples were collected in each of the two sampling periods, with the first period being high tide and the other with low tide. For the homogeneity of the results, the distance between the sampling points was 1100m, making the total of 18km. By evaluating the results obtained, one can notice that in the mixing of the waters three very distinct zones are formed: the first is the one in which there is predominance of continental water; the second is where the mixture of continental and oceanic waters occurs and the third is where there is predominance of oceanic water. In the second sampling zone, the increase in the values of the obtained results is clearly observed, the closer they are to the mouth of the river.

Abundance, relative growth and fecundity of Emerita rathbunae Schmitt, 1935 (Decapoda, Anomura, Hippidae) in the S.E. Gulf of California, Mexico

Specimens of the mole crabEmerita rathbunaeSchmitt, 1935, were collected during a one-year period along two sandy beaches in the S.E. Gulf of California, Mexico. A total of 2171 specimens were examined. Only 8% of the collected females were ovigerous. The large majority of males (95%) were collected in the sand as “free living” males, while the rest (39 individuals) were “dwarf males”, with developed genital papilla, 95% of which were found attached to females. Density for pooled samples reached an overall maximum of 309.8 orgs/m2in February and a minimum in April (65.0 orgs/m2). Females always outnumbered males, except in February. Ovigerous females were observed in the first half of the study period (February to September). Proportions of males were very similar throughout the study period, while indeterminate specimens were proportionally more abundant in its second half. Relationships between CW and CL for both males and females were highly correlated and isometric. Relationships between size and weight were highly correlated in both males and non-ovigerous females for pooled samples or for each sampling zone, and in each case growth was isometric. The number of eggs per ovigerous female varied considerably, from 910 to 22 866, and the relationship between number of eggs per batch and body size was poorly correlated. In the study area,E. rathbunaeappears to have a rather restricted reproduction period. A larger series of data combined with the analysis of other environmental factors, such as beach profiles, current patterns and primary productivity, might bring some additional information on this species biology and ecology. Due to the key role that mole crabs play in the food web of sandy beaches, special attention should be provided to this particular habitat.

Multiplex Single Molecule Detection Module for Stroke Diagnosis

A polymer-based, multiplex single molecule detection module (SMD) was developed with a fluidic substrate and a cover plate. The fluidic substrate was fabricated using a single-step, double-sided hot embossing in poly(methyl methacrylate) (PMMA) with sampling zone microchannels on the bottom side and microlenses on the top. Shallow sampling zone microchannels (5 μm deep and 100 μm wide) were made to improve sampling efficiency and microlenses were adopted to collect the fluorescent radiation from the sampling zone microchannels. A cyclic olefin copolymer (COC) embedded waveguide in PMMA along with an integrated coupling prism was fabricated using polydimethylsiloxane (PDMS) stencils and melted COC (40% w/v in toluene) on the cover plate. The COC waveguide with a COC integrated coupling prism will be used for evanescent excitation of fluorescent samples in the sampling zone microchannels. The fluidic substrate was bonded with the cover plate using thermal fusion bonding based on a pressure-assisted boiling point control system. This approach allowed for sealing of shallow microchannels without observable sagging of the cover plate, which was confirmed by leakage testing with fluorescent dyes. The completed SMD module will be tested for characterization of the optical performances such as signal-to-noise ratio and sampling efficiency and it will provide the capability for rapid screening of stroke at low cost.

Activity and diversity of methane-oxidizing bacteria in glacier forefields on siliceous and calcareous bedrock

The global methane (CH4) cycle is largely driven by methanogenic archaea and methane-oxidizing bacteria (MOB), but little is known about their activity and diversity in pioneer ecosystems. We conducted a field survey in forefields of 13 receding Swiss glaciers on both siliceous and calcareous bedrock to investigate and quantify CH4 turnover based on soil-gas CH4 concentration profiles, and to characterize MOB communities using pmoA sequencing and T-RFLP. Methane turnover was fundamentally different in the two bedrock categories. Of the 36 CH4 concentration profiles from siliceous locations, 11 showed atmospheric CH4 consumption at concentrations of ∼1–2 μl l−1 with soil-atmosphere CH4 fluxes of −0.14 to −1.1 mg m−2 d−1. Another 11 profiles showed no apparent activity, while the remaining 14 exhibited slightly increased CH4 concentrations of ∼2–10 μl l−1, most likely due to microsite methanogenesis. In contrast, all profiles from calcareous sites suggested a substantial, yet unknown CH4 source below our sampling zone, with soil-gas CH4 concentrations reaching up to 1400 μl l−1. Remarkably, most soils oxidized ∼90% of the deep-soil CH4, resulting in soil-atmosphere fluxes of 0.12 to 31 mg m−2 d−1. MOB showed limited diversity in both siliceous and calcareous forefields: all identified pmoA sequences formed only 5 OTUs and, with one exception, could be assigned to either Methylocystis or the as-yet-uncultivated Upland Soil Cluster γ (USCγ). The latter dominated T-RFLP patterns of all siliceous and most calcareous samples, while Methylocystis dominated in 4 calcareous samples. As Type I MOB are widespread in cold climate habitats with elevated CH4 concentrations, USCγ might be the corresponding Type I MOBs in habitats exposed to near-atmospheric CH4 concentrations.