Parasitic helminth infections have a considerable impact on global human health as well as animal welfare and production. Although co-infection with multiple parasite species within a host is common, ...there is a dearth of tools with which to study the composition of these complex parasite communities. Helminth species vary in their pathogenicity, epidemiology and drug sensitivity and the interactions that occur between co-infecting species and their hosts are poorly understood. We describe the first application of deep amplicon sequencing to study parasitic nematode communities as well as introduce the concept of the gastro-intestinal "nemabiome". The approach is analogous to 16S rDNA deep sequencing used to explore microbial communities, but utilizes the nematode ITS-2 rDNA locus instead. Gastro-intestinal parasites of cattle were used to develop the concept, as this host has many well-defined gastro-intestinal nematode species that commonly occur as complex co-infections. Further, the availability of pure mono-parasite populations from experimentally infected cattle allowed us to prepare mock parasite communities to determine, and correct for, species representation biases in the sequence data. We demonstrate that, once these biases have been corrected, accurate relative quantitation of gastro-intestinal parasitic nematode communities in cattle fecal samples can be achieved. We have validated the accuracy of the method applied to field-samples by comparing the results of detailed morphological examination of L3 larvae populations with those of the sequencing assay. The results illustrate the insights that can be gained into the species composition of parasite communities, using grazing cattle in the mid-west USA as an example. However, both the technical approach and the concept of the 'nemabiome' have a wide range of potential applications in human and veterinary medicine. These include investigations of host-parasite and parasite-parasite interactions during co-infection, parasite epidemiology, parasite ecology and the response of parasite populations to both drug treatments and control programs.
There is currently great interest in replacing the harmful volatile hydrofluorocarbon fluids used in refrigeration and air-conditioning with solid materials that display magnetocaloric, ...electrocaloric or mechanocaloric effects. However, the field-driven thermal changes in all of these caloric materials fall short with respect to their fluid counterparts. Here we show that plastic crystals of neopentylglycol (CH
)
C(CH
OH)
display extremely large pressure-driven thermal changes near room temperature due to molecular reconfiguration, that these changes outperform those observed in any type of caloric material, and that these changes are comparable with those exploited commercially in hydrofluorocarbons. Our discovery of colossal barocaloric effects in a plastic crystal should bring barocaloric materials to the forefront of research and development in order to achieve safe environmentally friendly cooling without compromising performance.
The article presents physical and theoretical generalizations of the space-time metrics, based on invariant coordinate time transformations over the intervals of the observed periodic emission of ...pulsars. Synchronization of spatial reference systems by the observed passage of the wave front of the coherent radiation of a pulsar corresponds to the axiomatic matching of coordinate time scales defined by the observed rotation parameters of the pulsar with the initial coordinates of spatial reference frames within the homogeneous Galileo space of the Galaxy. As a result, all physical processes in such coordinates systems, including the observed coherent radiation of a pulsar, are indistinguishable from each of them. The estimated span of minimum recognizable on the pulsar time scale is 10−12-10−14 s in the extent from several years to several decades and then gradually decreases, reaching limit values of the order of 10−16-10−17 s in the extent compared to the lifetime of a pulsar. The relative size of the resolved interval is within approximately 10−19-10−29.
The physicochemical and emulsifying properties of lentil protein isolates (LPI) were investigated as a function of their degree of hydrolysis (DH of 4, 9 and 20%) following exposure to trypsin/heat. ...Specifically, interfacial tension, surface characteristics (charge and hydrophobicity) and intrinsic fluorescence were determined. These parameters were then related to changes in the emulsification activity (EAI) and stability indices (ESI) of unhydrolyzed (u-LPI) and hydrolyzed LPI (h-LPI) in a flaxseed oil–water emulsion. Interfacial tension was found to decrease from ~6.5 to ~6.1mN m−1 for u-LPI and h-LPI (DH 4–20%), respectively. A similar trend was observed for surface hydrophobicity, which declined from ~30 to ~24 for the u-LPI and h-LPI (DH 4–20%), respectively. In contrast, surface charge values were similar for all materials (~−37mV). Intrinsic fluorescence as a function of emission wavelengths (300–400nm) indicated a slight change in the tertiary conformation of LPI upon hydrolysis, where the magnitude of fluorescence intensity declined relative to that of u-LPI. Changes in physicochemical properties upon hydrolysis had a detrimental effect on EAI and ESI values, which declined from ~51 to ~47m2g−1 and ~12 to ~11min for u-LPI and h-LPI (DH 4–20%), respectively.
► Limited hydrolysis of lentil proteins negatively impacted emulsifying properties. ► Limited hydrolysis of lentil proteins led to a decrease in surface hydrophobicity. ► Physiochemical and emulsifying properties were similar over the DH range of 4–20.
We obtain the es - as series of simultaneous and joint rotational motions of the planets. Copernicus (1473-1543 analytical coordinate-independent pulsar time scales, which are determined by the ...observed rotation parameters of pulsar. The scales extent into barycentric and any topocentric coordinate systems, providing simultaneity of the observed physical phenomena, including the periodic radiation of a pulsar as well, in any point of the three-dimensional space.
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•Nemabiome deep amplicon sequencing is a powerful new approach to explore cattle gastro-intestinal nematode communities.•Low parasite species diversity was found in Canadian cattle ...compared with more southerly regions.•Ostertagia ostertagi is the most prevalent gastro-intestinal nematode species in Canadian cattle.•Low treatment effectiveness of macrocyclic lactones was found in Canadian beef cattle.•There was an increase in Cooperia spp. relative to O. ostertagi after ivermectin treatment.
Next-generation deep amplicon sequencing, or metabarcoding, has revolutionized the study of microbial communities in humans, animals and the environment. However, such approaches have yet to be applied to parasitic helminth communities. We recently described the first example of such a method – nemabiome sequencing – based on deep-amplicon sequencing of internal transcribed spacer 2 (ITS-2) rDNA, and validated its ability to quantitatively assess the species composition of cattle gastro-intestinal nematode (GIN) communities. Here, we present the first application of this approach to explore GIN species diversity and the impact of anthelmintic drug treatments. First, we investigated GIN species diversity in cow-calf beef cattle herds in several different regions, using coproculture derived L3s. A screen of 50 Canadian beef herds revealed parasite species diversity to be low overall. The majority of parasite communities were comprised of just two species; Ostertagia ostertagi and Cooperia oncophora. Cooperia punctata was present at much lower levels overall, but nevertheless comprised a substantive part of the parasite community of several herds in eastern Canada. In contrast, nemabiome sequencing revealed higher GIN species diversity in beef calves sampled from central/south-eastern USA and Sao Paulo State, Brazil. In these regions C. punctata predominated in most herds with Haemonchus placei predominating in a few cases. Ostertagia ostertagi and C. oncophora were relatively minor species in these regions in contrast to the Canadian herds. We also examined the impact of routine macrocyclic lactone pour-on treatments on GIN communities in the Canadian beef herds. Low treatment effectiveness was observed in many cases, and nemabiome sequencing revealed an overall increase in the proportion of Cooperia spp. relative to O. ostertagi post-treatment. This work demonstrates the power of nemabiome metabarcoding to provide a detailed picture of GIN parasite community structure in large sample sets and illustrates its potential use in research, diagnostics and surveillance.
The paper presents a low-dimensional model of bioconvective flow for gyrotactic microorganisms. The problem was solved based on the Lorenz approach. This model enabled determining boundaries of ...different flow regimes. With the help of analytical and numerical methods, four criteria for the stability of bioconvective flows were identified in the form of Rayleigh numbers. These criteria determine the boundaries of the onset of the regimes of monotonous bioconvection Racr1∗, oscillating instabilities Racr2∗, turbulent pulsations Racr3∗ and developed turbulent flow Racr4∗. The features of the dependences of the critical Rayleigh numbers on the Schmidt number and the parameter α0 (describing the geometric structure of microorganisms) are analyzed.
•Low-dimensional model of bioconvective flow for gyrotactic microorganisms was proposed.•Lorenz approach was used to solve the problem.•Boundaries of different flow regimes were determined.•Four Rayleigh numbers as stability criteria of bioconvective flows were identified.
Abstract
The article considers a complex of geometric representations of space-time, based on general dynamic theories of celestial mechanics in close connection with pulsar astrometry as the ...physical basis of coordinate-time transformations within the solar system and galactic space as a whole. The pulsar time scale is considered as a certain material system with continuous and stable motion, representing a certain measurable parameter – the rotation period
P
, which changes as a function of the independent time variable – its derivative. The physical pulsar scale is a sequence of measured daily increments of the initial radiation period within any duration. According to observations at the BSA radio telescope (Pushchino) of the pulsar B0950+08, the time scale was determined with an initial period of P
0
=0.2530653211840410 s on the date MJD
0
= 58971 (02.05.2020; 21h.58m.07s). A measured daily increment ΔP = 1.4441·10E-11 s corresponds to the measured value of the derivative P = 1.6759949886E-16, which is determined by the observational timing data. Measured ΔP are defined in the 25th decimal place. Up to 14-15 digits, Δ P there is a pulsar time scale with femtosecond resolution. From 15-16 to 25 digits Δ P is presumably sequential fixation of discrete states of microparticles during quantum-mechanical interactions of matter and electromagnetic radiation of a pulsar. According to our hypothesis, the diversity of the material world and physical processes occurring in celestial and quantum mechanics are finite and it can be generalized. This implies the inseparable unity of physical laws in four-dimensional space of celestial and quantum mechanics, detectable on pulsar time scales under the same conditions.
The paper analyses a novel model of unsteady convective heat transfer in a nanofluid layer on a flat vertical surface subject to instantaneous (abrupt) onset of film boiling. It occurs if heat flux ...suddenly switched on exceeds the critical heat flux necessary to bring a nanofluid to film boiling regime. The usual system of equations of fluid flow and convective heat transfer is supplemented by an equation for the concentration of nanoparticles. To complement the problem statement, two sets of the boundary and initial conditions were used. The first condition corresponds to problem of film boiling derived by Bromley, whereas the second was suggested by Ellion for a stationary liquid at the vapor-liquid interface. The solution of the problem enabled predicting variation of temperature distributions, Nusselt numbers, velocity profiles and friction coefficients in time. Computations were performed numerically based on the self-similar equations derived using the Lie group transformations. Results of unsteady simulations of convective heat transfer during instantaneous onset of film boiling of a nanofluid with different concentrations of nanoparticles demonstrated qualitative agreement with experiments.
•Instantaneous transition to film boiling in nanofluids was studied at sudden heat input.•Unsteady convective heat transfer in the vapor film was modeled theoretically.•The problem was solved analytically and analyzed for two sets of boundary conditions.•The theoretical solution was successfully validated via comparisons with experiments.
The paper focused on an analytical analysis of the main features of heat transfer in incompressible steady-state flow in a microconfusor with account for the second-order slip boundary conditions. ...The second-order boundary conditions serve as a closure of a system of the continuity, transport, and energy differential equations. As a result, novel solutions were obtained for the velocity and temperature profiles, as well as for the friction coefficient and the Nusselt number. These solutions demonstrated that an increase in the Knudsen number leads to a decrease in the Nusselt number. It was shown that the account for the second-order terms in the boundary conditions noticeably affects the fluid flow characteristics and does not influence on the heat transfer characteristics. It was also revealed that flow slippage effects on heat transfer weaken with an increase in the Prandtl number.
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