bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Pyrolysis on Biogas Production during Anaerobic Co-digestion of Corn Stover
Authors: Na Risu , Kushima Keisuke , Shimizu Naoto
Published: January 2021

The effects of pyrolysis pretreatment on biogas production during anaerobic co-digestion of corn stover were studied. The corn stover characteristics were investigated by performing thermogravimetric analysis using a heating rate of 10.0°C/min and an air atmosphere at atmospheric pressure. Corn stover aliquots pretreated in an electric furnace at 100°C for 360 min, 200°C for 15 min, and 300°C for 5 min were used. Untreated and pretreated corn stover samples were analyzed by scanning electron microscopy and other methods, and the bulk densities and component ratios were compared to identify changes caused by the pretreatments. The amounts of total solids, volatile solids, volatile fatty acids, and total ammonia nitrogen produced when the stover samples were anaerobically digested were measured. The biogas production rate and the methane concentration in the biogas were determined. The substrate-specific methane yields were determined, and the relationships between the yields and pretreatment conditions were assessed. The sample pretreated at 300°C for 5 min produced the most biogas. The corn stover total solid bulk density was directly related to the substrate-specific methane yield, the substratespecific methane yield decreasing as the total solid bulk density increased.
Design of 10 kW Low Temperature Power Cycle Using Amine— CO2 Fluid
Authors: Ogawa Takashi , Mawatari Takashi , Itoh Akira , Yamamoto Yasushi
Published: January 2021

Our thermodynamic study indicated that low temperature power cycle using amine-CO2 fluid can obtain the performance equal to or higher than that of the current organic Rankine cycle. We designed a 10 kW test equipment. We set high temperature heat source is hot water at the temperature of 90°C and the flow rate of 8,200kg/h, which is a coolant from a gas engine. The heat and mass balance of the equipment was calculated thermodynamically. The result showed the power of 10.5kW and the system efficiency of 7.3 per cent at the the amine – CO2 fluid flow rate of 1,000kg/h, and the turbine expansion ratio of 4.8. The preliminary estimation shows as follows. The diameter and rotational speed of the turbine blade are 0.115m and 54,400min-1, respectively. The number, width, and length of the recuperator plates are 20, 117mm, and 835mm, respectively. The height and cross sectional area of the absorption bed are 0.35m and 0.027m2, respectively.
Synthesis of Silver Doped Titanium Dioxide by Wet-Ball Milling Sol–Gel Method for Antibacterial Application
Authors: Eksangsri Tippabust , Sapcharoenkun Chaweewan , Phromma Siripond
Published: January 2021

Titanium dioxide (TiO2) has been extensively studied as photo-catalyst for water treatment, air purification and antibacterial applications due to its challenging properties such as chemical stability, environmental friendly and strong photocatalytic activity. However, the limitation of TiO2 on its dependent to ultraviolet radiation for photocatalytic activity is still aroused. In this study, silver doped titanium dioxide (Ag-TiO2) was synthesized by wet-ball milling sol–gel method (WBMS). Ag-TiO2 molar ratio was varied from 0% to 10% to study the effect of silver content on the synthesized Ag-TiO2 characteristics and the ability to apply on antibacterial applications. The objective of this work was to find an optimal concentration of Ag in Ag-TiO2. Characterization of the particle size, morphology, and surface area of synthesized Ag-TiO2 were discussed by techniques of transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). Photocatalytic activity was investigated from degradation of methylene blue. Antibacterial activity was conducted by finding minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests performed on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) under dark condition and under visible light. The results demonstrated that the doping of Ag inhibited crystal growth of Ag-TiO2. The smallest particle size and the highest surface area were obtained from 5% Ag-TiO2. Also, it was found that methylene blue degradation rate increased to the highest number of 1.62x10−3 min−1 when Ag concentration reached 5%, and methylene blue degradation rate reduced when Ag concentration was higher than 5%. The antibacterial activity of Ag-TiO2 was better than TiO2. The optimal concentration of 3-5% Ag-TiO2 was observed from the MIC and MBC tests.
Geopolymerization of Coal Fly Ash, Ceramic Tile Waste and Spent Bleaching Earth for the Production of Sodium Aluminosilicate Monolith
Authors: Macasil Renzo , Redublo Anne Paulinne , Santos Amabelle , Torres Clark Ivan , Pangayao Denvert
Published: January 2021

In this study, compressive strength, density, porosity, and methylene blue adsorptive intensity of sodium aluminosilicate monolith produced from coal fly ash (CFA), ceramic tile waste (CTW), and spent bleaching earth (SBE) were evaluated. Using simple lattice mixture design, CFA-CTW-SBE blend with mass ratio of 55.95% CFA, 38.73% CTW, and 5.31% SBE, and an alkali solution containing 80% 8M NaOH and 20% sodium silicate, resulted to a maximum desirability of 12.4MPa compressive strength, 1310 kg/m3 density, 17.03% porosity, and 1.63% methylene blue adsorption intensity. The properties of the product conform to the specifications of ASTM C90-14 for lightweight load-bearing concrete.
Loading Silica for Supporting Carbon Black Filler to Prevent Degradation Natural Rubber Caused DME
Authors: Saputra Asep Handaya , Sari Tuti Indah , Maspanger Dadi R. , Bismo Setijo
Published: January 2021

DME (Dimethyl Ether) is the future environmental friendly fuel. Some parts of equipment for transporting the DME are using rubber as a hoses or seals. This research is about the using of natural rubber for those applications. The influential part in the manufacture of natural rubber products are fillers. The use of filler depends on what the product will be made. DME nature have high permeability and easy to absorb into a rubber and plastic. In such of that, the rubber or plastic could be damaged and not durable. In order to determine the type of degradation, the number of samples were immersed in liquid DME. The ratio of the loading of carbon black/silica filler in natural rubber was varied. DME causes two types of degradation, namely absorption and extraction. The addition of filler composition can reduce the absorption and extraction, which can cause a reduction in the percentage decrease in the value of the change in mass and a decrease in tensile strength. On the other hand, the addition of filler composition will increase the changes of hardness. The higher filler loading, will increase the crosslink density and lower scorch time. The presence of silica further is to enhance the crosslink density as well as to lower scorch time. Therefore, the presence of silica affect on the decreasing of the swelling level and shrinking. In general, the presence of silica filler in the mixture will be slightly lowering the tensile strength, but not affecting the elongation at break. The presence of silica before and after soaking with DME will increase hardness.
Übersicht der Heilmittel-Richtlinie einschließlich
des Heilmittelkatalogs – unter besonderer Berücksichtigung der
Änderungen (gültig ab 01.01.2021)
Authors: Ranker Alexander , Lemhöfer Christina , Lehmann Julius , Liebl Max
Published: January 2021

Zum 01.01.2021 tritt eine Erneuerung der Heilmittel-Richtlinie
einschließlich des Heilmittelkatalogs in Kraft. Dies zielt auf eine
Entbürokratisierung sowie eine Verbesserung der
Übersichtlichkeit und Transparenz des Verordnungsprozesses ab. Der
Beitrag stellt Heilmittel und Heilmittelverordnungen im gesetzlichen
Krankenversicherungssystem (GKV) und die Neuerungen als Übersicht
dar. Zudem wird das neue Verordnungsformular 13 vorgestellt.
Competition reduces profitability: the case of the Indian life microinsurance industry
Authors: Banerjee Subrato , Savitha Basri
Published: January 2021

We aim to understand the effect of market and firm-level concentration on return on equity in the Indian life microinsurance industry (LMI). This research is one of the first attempts to empirically test structure–performance issues in India. Using data on 14 companies that remained active in the LMI market during 2009–2019, we demonstrate that firms in the Indian LMI market scored better on profitability measures whenever competitive pressures were lower. We calculate Herfindahl–Hirschman concentration indexes (HHI), market share and entropy measures and use panel data techniques to find a positive effect of concentration and a negative effect of market share. We conclude that LMI-specialised insurers in India perform better than diversified insurers.
A refined model for epitaxial tilt of elastically strained epilayers grown on miscut substrates
Authors: Liao Michael E. , Goorsky Mark S.
Published: January 2021

A refined model of the origin of epitaxial tilt on miscut (or vicinal) substrates due to elastic lattice deformation is presented. The Nagai tilt model [Nagai, J. Appl. Phys. 45, 3789 (1974)] is often cited to explain the tilt of low index lattice planes in a pseudomorphic layer deposited on a miscut substrate that is observed in, for example, high resolution x-ray diffraction measurements. Here, however, we show that the Nagai model applies biaxial stress incorrectly to the epitaxial layer. Most importantly, the stress applied to an epitaxial layer on a miscut substrate is not along a low index plane but is rather along the surface plane. For example, the surface plane of a nominally (001) cubic substrate with a miscut of 10° toward [110] is the (118) plane and the stress applied is parallel to the (118) plane and not (001). Furthermore, under the framework of reciprocal space, the {00l} reflections would be symmetric reflections for on-axis substrates but asymmetric reflections for miscut substrates. The tilt that is experimentally observed between the low index substrate planes and the epitaxial layer planes [(001) for example with a miscut substrate] matches that which is predicted by treating the low index reflections as asymmetric reflections. An epitaxial tilt equation is provided which describes the tilt between epitaxial and substrate layers based on the lattice parameter mismatch as well as Poisson’s ratio of the layer that is applicable to any crystal system. This approach negates the need for the uneven distortions at the interface that are presented in the Nagai illustration. The approach presented here shows that a physically accurate biaxial deformation accounts for all of the observed experimental phenomena and provides a direct approach to determining the unit cell distortions.
Angular dependence and absorption properties of the anapole mode of Si nano-disks
Authors: Fornasari L. , Passoni M. , Marabelli F. , Chen Y. , Wang Y. , Dal Negro L.
Published: January 2021

The polarization- and angle-resolved optical responses of the anapole mode in silicon nano-disks array have been experimentally and theoretically investigated. The good agreement between measured data and simulations yields to a consistent description of the anapole mode behavior that exhibits different features for TE or TM polarization excitation. Scattering matrix calculation allows us to disentangle scattered and diffused light contributions and to provide a quantitative estimation of the absorbance enhancement associated with 2D excitation of the anapole mode. We performed the multipolar decomposition of the far-field scattered radiation for both TE and TM polarizations and unambiguously identified the anapole resonant condition in excellent agreement with the experimental results over a large range of incident angles. Our findings demonstrate the controlled excitation of electromagnetic anapole modes in engineered arrays of silicon nano-disks for the development of optical nanostructures with enhanced light–matter interaction.
Noise spectroscopy of molecular electronic junctions
Authors: Kim Youngsang , Song Hyunwook
Published: January 2021

Over the past few decades, the field of molecular electronics has greatly benefited from advances in the fundamental understanding of charge transport mechanisms. Molecular junctions represent a field whose potential is realized through detailed studies of charge transport on the nanoscale. Applications of molecular junctions, such as molecular logic circuits, rely on precise mechanistic information as investigative techniques are refined. Current advances have originated from improvements in a variety of characterization techniques, with noise spectroscopy contributing to key studies of transport phenomena. Noise spectroscopy has shown to be useful for probing latent electronic characteristics in molecular junctions, giving insight beyond standard methods of charge transport study. This review presents an in-depth background on fundamental concepts in electronic noise spectroscopy, covering topics such as flicker, generation-recombination, random telegraph signal, and shot noises. Recent advances in noise spectroscopy techniques and their applications to the study of molecular junctions are discussed, highlighting the impact of this technique in the improvement of molecular junction stability and reliability, the study of interference in charge transport, and the emergence of vibrational excitation phenomena. This review provides a comprehensive understanding of noise analyses in the field of molecular junctions and gives insight for further advances in molecular and nanoscale electronics.
Active motion of passive asymmetric dumbbells in a non-equilibrium bath
Authors: Belan Sergey , Kardar Mehran
Published: January 2021

Persistent motion of passive asymmetric bodies in non-equilibrium media has been experimentally observed in a variety of settings. However, fundamental constraints on the efficiency of such motion are not fully explored. Understanding such limits, and ways to circumvent them, is important for efficient utilization of energy stored in agitated surroundings for purposes of taxis and transport. Here, we examine such issues in the context of erratic movements of a passive asymmetric dumbbell driven by non-equilibrium noise. For uncorrelated (white) noise, we find a (non-Boltzmann) joint probability distribution for the velocity and orientation, which indicates that the dumbbell preferentially moves along its symmetry axis. The dumbbell thus behaves as an Ornstein–Uhlenbeck walker, a prototype of active matter. Exploring the efficiency of this active motion, we show that in the over-damped limit, the persistence length l of the dumbbell is bound from above by half its mean size, while the propulsion speed v∥ is proportional to its inverse size. The persistence length can be increased by exploiting inertial effects beyond the over-damped regime, but this improvement always comes at the price of smaller propulsion speeds. This limitation is explained by noting that the diffusivity of a dumbbell, related to the product v∥ l, is always less than that of its components, thus severely constraining the usefulness of passive dumbbells as active particles.
Diffusion Monte Carlo method on small boron clusters using single- and multi- determinant–Jastrow trial wavefunctions
Authors: Peng Yun , Zhou Xiaojun , Wang Zhifan , Wang Fan
Published: January 2021

Multireference character in some small boron clusters could be significant, and a previous all-electron fixed-node diffusion quantum Monte Carlo (FN-DMC) calculation with the single-determinant-Jastrow (SDJ) trial wavefunction shows that the atomization energy (AE) of B4+ is overestimated by about 1.4 eV compared with the coupled cluster method with single, doubles, and perturbative triples [CCSD(T)] results. All-electron FN-DMC calculations and those with the pseudopotential (PP) using SDJ and multi-determinant-Jastrow (MDJ) trial wavefunctions with B3LYP orbitals as well as CC calculations at different levels are carried out on BnQ (n = 1–5, Q = −1, 0, 1) clusters. The obtained FN-DMC energies indicate that the node error of the employed SDJ trial wavefunction in all-electron calculations is different from that with the PP for some clusters. The error of AEs and dissociation energies (DEs) from all-electron FN-DMC calculations is larger than that with the PP when the SDJ trial wavefunction is employed, while errors of CC methods do not depend on whether the PP is used. AEs and DEs of the boron clusters are improved significantly when MDJ trial wavefunctions are used in both all-electron calculations and those with the PP, and their error is similar to that of CCSD(T) compared with CCSDT(Q) results. On the other hand, reasonable adiabatic electron detachment energies (ADEs) and ionization potentials (AIPs) are achieved with FN-DMC using SDJ trial wavefunctions and MDJ is less effective on ADEs and AIPs. Furthermore, the relative energy between two structures of B9− is predicted reliably with FN-DMC using the SDJ trial wavefunction and the effect of MDJ is negligible, while density functional theory results using different exchange-correlation functionals differ significantly.
SSIA: A sensitivity-supervised interlock algorithm for high-performance microkinetic solving
Authors: Chen Jianfu , Jia Menglei , Lai Zhuangzhuang , Hu Peijun , Wang Haifeng
Published: January 2021

Microkinetic modeling has drawn increasing attention for quantitatively analyzing catalytic networks in recent decades, in which the speed and stability of the solver play a crucial role. However, for the multi-step complex systems with a wide variation of rate constants, the often encountered stiff problem leads to the low success rate and high computational cost in the numerical solution. Here, we report a new efficient sensitivity-supervised interlock algorithm (SSIA), which enables us to solve the steady state of heterogeneous catalytic systems in the microkinetic modeling with a 100% success rate. In SSIA, we introduce the coverage sensitivity of surface intermediates to monitor the low-precision time-integration of ordinary differential equations, through which a quasi-steady-state is located. Further optimized by the high-precision damped Newton’s method, this quasi-steady-state can converge with a low computational cost. Besides, to simulate the large differences (usually by orders of magnitude) among the practical coverages of different intermediates, we propose the initial coverages in SSIA to be generated in exponential space, which allows a larger and more realistic search scope. On examining three representative catalytic models, we demonstrate that SSIA is superior in both speed and robustness compared with its traditional counterparts. This efficient algorithm can be promisingly applied in existing microkinetic solvers to achieve large-scale modeling of stiff catalytic networks.
The planar spread of a liquid jet and hydraulic jump on a porous layer
Authors: Wang Yunpeng , Khayat Roger E.
Published: January 2021

The flow of a planar liquid free surface jet impinging on a porous layer is theoretically examined, with particular emphasis on the influence of porosity ϕ, stress jump coefficient χ, and depth of the porous layer on the super- and sub-critical regions. Despite the numerous studies in the literature on the flow over a porous medium, the jet impingement on a porous layer has not been studied. An averaging integral approach is adopted to capture the flow in the developing boundary-layer and fully viscous regions upstream of the hydraulic jump. Asymptotic analyses for small distance from impingement, small porosity, and small porous layer depth are also conducted, elucidating the various mechanisms behind the behavior predicted numerically. We find a domain of validity for the stress jump coefficient χ in which numerical and experimental values of χ from the literature seem to fall. The transition point, where the outer edge of the boundary layer intersects the film surface, moves downstream with increasing porosity and stress jump coefficient accompanied by a drop in the film thickness. While the height of the hydraulic jump generally decreases with increasing ϕ for any permeability, the jump location decreases for small χ and increases for large χ.
Atomistic-scale insight into the polyethylene electrical breakdown: An eReaxFF molecular dynamics study
Authors: Akbarian Dooman , Ganeshan Karthik , Woodward W. H. Hunter , Moore Jonathan , van Duin Adri C. T.
Published: January 2021

Cross-linked polyethylene (XLPE) has been recognized as an outstanding insulator for high-voltage power cables due to its favorable structural integrity at high temperature, low moisture sensitivity, chemical resistance, and low rates of failure due to aging. However, the roles of by-products and amorphous regions generated during the XLPE production are not clearly known at the atomistic scale. In this study, we present an eReaxFF-based molecular dynamics simulation framework with an explicit electron description verified against density functional theory data to investigate the roles of XLPE by-products and processing variables such as density and voids on the time to dielectric breakdown (TDDB) of polyethylene (PE). Our simulation results indicate that an increase in density of PE increases the TDDB; however, adding a by-product with positive electron affinity such as acetophenone can reduce the TDDB. Furthermore, during the electrical breakdown in PE, electrons tend to migrate through voids when transferring from the anode to cathode. In comparison with neutral acetophenone, we find that the acetophenone radical anion can significantly reduce the energy barrier and the reaction energy of secondary chemical reactions.
Realization of incompressible Navier–Stokes flow as superposition of transport processes for Clebsch potentials
Authors: Sato Naoki
Published: January 2021

In ideal fluids, Clebsch potentials occur as paired canonical variables associated with the Hamiltonian description of the Euler equations. This paper explores the properties of the incompressible Navier–Stokes equations when the velocity field is expressed through a complete set of paired Clebsch potentials. First, it is shown that the incompressible Navier–Stokes equations can be cast as a system of transport (convection–diffusion) equations where each Clebsch potential plays the role of a generalized distribution function. The diffusion operator associated with each Clebsch potential departs from the standard Laplacian due to a term depending on the Lie-bracket of the corresponding Clebsch pair. It is further shown that the Clebsch potentials can be used to define a Shannon-type entropy measure, i.e., a functional, different from energy and enstrophy, whose growth rate is non-negative. As a consequence, the flow must vanish at equilibrium. This functional can be interpreted as a measure of the topological complexity of the velocity field. In addition, the Clebsch parameterization enables the identification of a class of flows, larger than the class of two-dimensional flows, possessing the property that the vortex stretching term identically vanishes and the growth rate of enstrophy is non-positive.
Photothermal and photovoltaic properties of transparent thin films of porphyrin compounds for energy applications
Authors: Lin Jou , Shi Donglu
Published: January 2021

To address the critical issues in solar energy, the current research has focused on developing advanced solar harvesting materials that are low cost, lightweight, and environmentally friendly. Among many organic photovoltaics (PVs), the porphyrin compounds exhibit unique structural features that are responsible for strong ultraviolet (UV) and near infrared absorptions and high average visible transmittance, making them ideal candidates for solar-based energy applications. The porphyrin compounds have also been found to exhibit strong photothermal (PT) effects and recently applied for optical thermal insulation of building skins. These structural and optical properties of the porphyrin compounds enable them to function as a PT or a PV device upon sufficient solar harvesting. It is possible to develop a transparent porphyrin thin film with PT- and PV-dual-modality for converting sunlight to either electricity or thermal energy, which can be altered depending on energy consumption needs. A building skin can be engineered into an active device with the PT- and PV-dual modality for large-scale energy harvesting, saving, and generation. This review provides the current experimental results on the PT and PV properties of the porphyrin compounds such as chlorophyll and chlorophyllin. Their PT and PV mechanisms are discussed in correlations to their electronic structures. Also discussed are the synthesis routes, thin film deposition, and potential energy applications of the porphyrin compounds.
103 Characterization of the receptors of the endocannabinoid system in equine sperm: Possible role of anandamide in sperm function
Authors: Arroyo-Salvo C. , Lottero R. , Gambini A. , Martinez S. Perez
Published: January 2021

Conventional IVF in horses remains challenging. In particular, stallion sperm fails to penetrate the zona pellucida, possibly due to incomplete invitro sperm capacitation. Therefore, there is a need to elucidate, in horses, molecules with a proven role during capacitation in other mammals. Our laboratory has described the relevance of the endocannabinoid system in capacitation of bovine and murine sperm. We reported that anandamide (AEA), an endocannabinoid present in follicular and oviducal fluids, induced capacitation-associated events. The aims of this work were to characterise the localization of cannabinoid receptors in equine sperm and to evaluate the effects of AEA on levels of tyrosine-phosphorylated proteins (pY) and substrates phosphorylated by protein kinase A (pPKA). Both cannabinoid receptors (CB1, CB2, TRPV1) and pPKA and pY were localised in sperm by indirect immunofluorescence. Sperm (15×106mL−1) were incubated, at 38.5°C in air, in modified Tyrode’s-albumin-lactate-pyruvate (TALP) with 25mM NaHCO3, 5mM dextrose and 1mgmL−1 polyvinyl alcohol (PVA; TALP-Bic-PVA) or TALP-Bic-PVA supplemented with AEA (0.1, 1, 10, 100nM, and 1µM) for 4h. After incubation, Western blot was used to determine levels of pY and pPKA in 4.5×106 sperm. Cryopreserved sperm samples from three stallions were evaluated. The normality of data distributions and homoscedasticity were verified with the Shapiro-Wilk and Levene tests, respectively. Data were analysed by one-way ANOVA and Bonferroni post hoc test, with P<0.05 considered significant. Based on immunofluorescence, CB1 was mainly localised in the post-acrosomal region and flagellum (93.4%±5.5, mean±s.d.), CB2 in the post-acrosomal region and middle piece (89.9%±28.3), and TRPV1 in the post-acrosomal region and flagellum (89.3%±9). Sperm positive for pPKA had fluorescence in the middle piece and principal piece of the flagellum. Incubation with 1nM AEA for 4h induced a 61% increase in pPKA levels compared with TALP-Bic-PVA medium alone, with no induction of pY levels in any treatment. In conclusion, cannabinoid receptors were present in equine sperm, and incubation with AEA induced an increase in PKA activity, an essential event associated with sperm capacitation. To our knowledge, this was the first report describing the presence of receptors of the endocannabinoid system in equine sperm and the potential role of AEA in the acquisition of sperm fertilizing ability.
106 Exogenous melatonin administration improves behavioural signs, serum melatonin, testosterone, and semen quality in male dromedary (Camelus dromedarius) camels
Authors: Dholpuria S. , Purohit G. N. , Vyas S.
Published: January 2021

The present study aimed to evaluate the effects of exogenous administration of melatonin to male camels on reproductive behaviour, seminal parameters, and serum concentrations of melatonin and testosterone during the non-breeding and subsequent breeding seasons. In September 2018, male camels (n=12) were randomly allocated to subcutaneous injections of either melatonin (MLT, 0.643 mg/kg; n=6) dissolved in corn oil, or plain corn oil; (control n=6). The camels were observed for behavioural signs of rut. A second dose of either MLT (1 mg/kg) or corn oil (control) was administered on 7 October 2018 subcutaneously, as camels did not show any change in behaviour until 6 October 2018, and the camels were again observed for behavioural signs of rut. Blood was collected from all camels on 1 September 2018, and then at weekly intervals until 7 January 2019. The serum was separated and stored until further assay of serum melatonin and testosterone using ELISA kits. Semen was collected from camels showing signs of rut period, and the reaction time, copulation time, and seminal parameters were evaluated. Data obtained was analysed by using the computer program SPSS (version 25; IBM Corp.), and means and standard errors were compared. Male reproductive behaviours (protrusion of soft palate, poll gland secretions, frequent urination, increased frothy salivation) were more pronounced in MLT-treated camels (83.33%) than in control camels (50%). Reaction time and copulation times were lower (112.81±30.06s and 229.8±37.91s) in MLT-treated camels than in controls (359.00±41.35s and 301.89±93.90s). Higher semen volume was observed in MLT-treated (5.34±2.06mL) than in control (3.11±1.75mL) camels (P<0.01). Semen collected from MLT-treated camels had more gel formation (81.25%), significantly higher sperm motility (67.50±2.32%), and increased sperm concentration (326.56±38.67 million mL−1) compared with samples obtained from the control males (P<0.01). Serum melatonin concentrations increased in both treated and control camels during the breeding season compared with concentrations before the breeding season. In MLT-treated camels, serum melatonin concentrations increased significantly and continued to be significantly higher than that in control camels for the entire study period (P<0.01). Serum testosterone concentrations were higher in both MLT-treated and control camels during the breeding season compared with those during the non-breeding season (P<0.01). We concluded that exogenous subcutaneous MLT administration improves sexual behaviour, seminal parameters, and serum testosterone concentrations during both the non-breeding and breeding seasons.
110 Pregnancy rate and embryo viability in response to chorionic gonadotrophins given for oestrus induction and gonadotrophin-releasing hormone 5 days after timed laparoscope-aided insemination of lactating and non-lactating goats
Authors: Calle M. , Dawson L. , Rojas M. , Loetz E.
Published: January 2021

Gonadotrophins are included in oestrous/ovulation synchronization (E/OS) regimens when breeding early in the transitional phase to promote follicular development. However, the time of use has been a matter of debate. Hence, the objective of this study was to determine whether equine and human chorionic gonadotrophins (eCG and hCG, respectively) given 24h before or 24h after concurrent removal of intravaginal progestagen (P4) and prostaglandin (PGF2α) delivery influences pregnancy rate (PR) and/or embryo viability (EV). Relatedly, the influence of gonadotrophin-releasing hormone (GnRH) 5 days post-breeding (dpb) on PR and/or EV was also considered. A prospective randomised control trial was conducted using lactating and non-lactating Alpine breed goats of different parity, average±s.e. age, and bodyweight (3.7±2.6), and (52.5±7), respectively. Goats were time-bred at 48h after P4 removal by laparoscopy (LAI; n=75) or by natural service (NS; n=29) during the early transitional breeding phase in mid-September through mid-December (corresponding to 12:12h daylight/darkness). E/OS used an intravaginal device containing 300mg of P4 for 12±1d. At P4 removal, 2mL of PGF2α was administered IM. Twenty-four hours before (E) or 24h after (L) P4 removal, an IM dose of 1.5mL containing 120IU of eCG and 60IU of hCG was given. A third control (C) group (n=38) was not exposed to gonadotrophins. GnRH analogue was given (n=51) 5 days after insemination, and the remaining goats (n=53) received an IM dose of 2mL of saline solution. PR was evaluated at 18 to 24 (dpb) by non-return to oestrus (NRE), at 30 dpb by pregnancy-specific protein B (PSPB), and at 40 dpb by ultrasound imaging (UI). EV was determined from the difference between pregnancy outcomes for NRE and PSPB, and PSPB and UI. Statistical analysis (JMP/SAS vs.11; SAS Institute Inc.) were obtained using logistic regression. All concomitant variables (i.e. parity, bodyweight, days of P4 exposure, and lactation were not influenced by PR or EV; P>0.07). The overall PR was 71% for LAI and 69% for NS and, as shown in Table 1, was similar (P>0.49) at all times (at 18 to 24, 30, and 40 dpb). Likewise, the breeding procedure did not influence the levels of EV at 30 or 40 dpb. E/OS protocol or the use of GnRH 5 dpb did not affect PR or EV at any of the time points evaluated.

Table 1.
Main effect mean comparisons and logistic model probabilities for pregnancy rate (PR) and embryo viability (EV) by main treatment effect

Response variable (days post-breeding)
Breeding procedure
E/OS Protocol
Gonadotrophin

LAI
NS
P>
Control
Early
Late
P>
GnRH
Placebo
P>

PR at 18–24
77
72
0.49
76
73
78
0.83
78
74
0.49

PR at 30
68
66
0.65
66
65
70
0.82
71
64
0.43

PR at 40
69
69
0.78
66
69
73
0.77
73
66
0.43

EV at 30
89
90
0.94
86
94
90
0.65
92
87
0.46

EV at 40
88
95
0.42
86
89
94
0.73
92
87
0.43
118 A comparison of intravaginal progesterone devices for fixed-time artificial insemination in beef cattle
Authors: Zwiefelhofer E. M. , Yang S. X. , Asai-Coakwell M. , Colazo M. G. , Hellquist J. , Zwiefelhofer M. L. , Anzar M. , Adams G. P.
Published: January 2021

Intravaginal progesterone (P4) devices used for ovarian synchronization before fixed-time AI (FTAI) differ in drug release, which may influence fertility outcome. A 2×2 study was designed to determine the effects of different intravaginal devices (PRID Delta, 1.55g of P4 vs. CIDR, 1.38g of P4) and parity (heifers vs. cows) on follicular dynamics, expression of oestrus, and pregnancy per AI (P/AI). At random stages of the oestrous cycle, nulliparous beef heifers and lactating cows were given 100µg of gonadorelin (gonadotrophin-releasing hormone, GnRH) intramuscularly (IM) and assigned randomly to either the PRID (n=76 heifers, 76 multiparous, 27 primiparous) or CIDR (n=76 heifers, 73 multiparous, 32 primiparous) group. Devices were removed 5 days later, an oestrus-detection patch was applied just cranial to the tail head, and 500µg of cloprostenol was given IM at the time of device removal and again 24h later. At 72h after device removal, cattle were inseminated and given 100µg of GnRH IM. Transrectal ultrasonography was used to determine the diameter of the largest follicle on the day of device removal and at FTAI, ovulation time, and pregnancy status 30 days after FTAI. A colour change of ≥50% of the oestrus-detection patch at FTAI was taken as expression of oestrus. Data were compared among groups by 2-way ANOVA using MIXED and GLIMMIX procedures. There were no interactions between P4 device and parity for any endpoint. The diameter of the largest follicle (mean±s.e.m.) was not different between PRID and CIDR groups on either the day of device removal (10.6±0.1 vs. 10.9±0.1mm) or the day of FTAI (13.7±0.1 vs. 13.9±0.1mm). The proportion displaying oestrus did not differ between P4 device groups, but was greater in heifers than in cows [121/152 (79.6%) vs. 135/207 (65.2%); P<0.01], and the interval from FTAI to ovulation was shorter in heifers than in cows (27.8±1.2 vs. 32.0±1.1 h; P=0.01). The P/AI was not different between P4 device groups or parity groups (overall 67.0%, 238/355). However, among lactating cows, the P/AI tended to be greater in the PRID vs. CIDR group [75/102 (73.5%) vs. 64/105 (61.0%); P=0.10], and was greater in multiparous vs. primiparous cows [106/148 (71.6%) vs. 33/59 (55.9%); P=0.04]. Among cattle that displayed oestrus, the P/AI tended to be greater in the PRID vs. CIDR group [92/123 (74.8%) vs. 85/131 (64.9%); P=0.09]. Among lactating cows that displayed oestrus, the P/AI was greater in multiparous vs. primiparous cows [74/94 (78.2%) vs. 24/42 (57.1%); P<0.01]. In summary, follicular dynamics and expression of oestrus did not differ between PRID and CIDR groups, but the P/AI tended to be greater in PRID-treated lactating cows and in cattle that displayed oestrus.
This research was supported by CEVA Animal Health, Saskatchewan ADF, Agriculture and Agri-Foods Canada, and Rockway Inc.
15 Blastocysts altered CDX2 and SOX2 gene expression and pregnancy failure after embryo transfer in yak heterospecific somatic cell nuclear transfer
Authors: Felipe M. Y. , Rodríguez M. D. , Ratner L. D. , De Stéfano A. , Valdez A. M. , Salamone D. F.
Published: January 2021

Heterospecific cloning is a tool for the genetic rescue of endangered animals. Our objective was to evaluate the effects of heterospecific yak (Bos grunniens) cloned embryo aggregation on the expression levels of NANOG, OCT4, CDX2, and SOX2 genes, and to compare with IVF, parthenogenetic zona-free (P-ZF), and homospecific bovine cloned embryos (BB1x). Oocytes were recovered from the ovaries of slaughtered cows and invitro matured for 22h. The zona pellucida was removed by protease treatment and then mature oocytes were enucleated by micromanipulation. Enucleated oocytes were placed in phytohemagglutinin to induce adherence with a somatic donor cell followed by electrofusion (with two 30-µs pulses of 1.2 kV/cm, 0.1s apart). Two hours after fusion, reconstructed embryos were activated using ionomycin followed by 6-(dimethylamino)purine (6-DMAP) treatment for 3h and cultured in synthetic oviductal fluid (SOF) medium for 7 days. The experimental groups were IVF, P-ZF, BB1x, heterospecific yak-bovine cloned embryos (1 embryo per microwell, YB1x), and heterospecific yak-bovine cloned embryos aggregated (2 embryos per microwell, YB2x). In all experimental groups, cleavage and blastocyst rates were assessed 7 days after activation. In addition, 5 blastocysts were pooled for each biological replicate, and pluripotency-specific genes (NANOG, SOX2, CDX2, and OCT4) were analysed by quantitative PCR. Data were analysed by the ΔΔCT method using the geometric mean of ACTB (actin) and GAPDH as internal standard followed by one-way ANOVA. Cleavages rates were significantly lower in the YB1x group compared with the other groups. Moreover, blastocyst rates in YB2x (31.34%, n=67) were significantly higher than in YB1x (13.86%, n=101) and BB1x (13.33%, n=45) groups, but there were no significant differences compared with the IVF (43.82%, n=89) and P-ZF (25%, n=68) groups. In contrast, although no significant differences were observed among groups in the expression of NANOG and OCT4 genes, the expression of CDX2 was lower in YB2x and YB1x blastocysts compared with the BB1X, P-ZF, and IVF (control) groups. In addition, a decrease in SOX2 gene expression was observed in the YB2x and YB1x blastocysts compared with the BB1X group. Blastocysts from YB1x (n=5) and YB2x (n=18) groups were transferred to recipient cows (n=23) on Day 7. Forty days after embryo transfer, presence of uterine fluid was detected by ultrasound in 3 recipient cows (from YB2x), suggesting embryo loss. In concordance with our previous reports, yak heterospecific SCNT blastocysts showed underexpression of CDX2 and SOX2 compared with the overexpression observed for these genes in bovine homospecific SCNT blastocysts. Thus, yak heterospecific SCNT blastocysts may have compromised developmental competence associated with altered expression of CDX2 and SOX2 that cannot be rescued by the aggregation of 2 reconstructed embryos.
28 Evaluation invitro of two protocols of vitrification from alpaca (Vicugna pacos) embryos
Authors: Huanca W. , Marin G. , Cordero A. , Uchuari M. , Huanca W. F.
Published: January 2021

The reproductive efficiency of South American camelids as the alpaca is low, with a few number of animals having a good genetic characteristic. The transfer of cryopreserved embryos has great potential to disseminate valuable genetic, but the suitable protocol for such cryopreservation still needs to be developed. In this study, two protocols of vitrification of alpaca embryos were tested. Day 6.5 post-mating, embryos (n=66) were recovered from 14 female alpacas through a non-surgical technique and classified according to the characteristics of old world camelids reported by Skidmore et al. 2004 (Reprod. Fertil. Dev. 16, 605–609). Only quality 1 and 2 embryos were used for the study. They were placed together in 50-µL drops of holding medium for 30min and transferred to a 100-µL drop of equilibration solution 1, consisting of 7.5% (v/v) ethylene glycol (EG) + 0.25M sucrose. After 1min, embryos were transferred to equilibration solution 2, consisting of 15% (v/v) EG + 0.5M sucrose. After 2min, embryos were transferred into 2 consecutive drops of vitrification solutions A [SA: 30% (v/v) EG + 1M sucrose] for 20s each, then in 2 other drops of vitrification solution B [SB: 30% (v/v) EG + 3% glycerol + 1M sucrose] for 20s each. Thereafter, embryos were quickly loaded into open pulled straws (OPS) in a volume of 10µL and then plunged into liquid nitrogen. For warming, the OPS were held in air for 5s and subsequently thawed at 37°C for 50s. Straws were emptied into 1mL of prewarmed holding medium solution (HMS1) containing 1M sucrose for wash and the thawed blastocysts were transferred into a second 1mL of prewarmed HMS1. After 5min incubation at 37°C, the blastocysts were transferred into 1mL of warmed Holding medium solution 2 (HMS2) containing 0.5M sucrose maintained at room temperature (∼24°C) for evaluation. Data were analysed by the Chi-squared test. Post-thaw embryo expansion results were 81.3% and 58.8% for SA and SB (P<0.05), respectively. Post-thaw embryo quality (1 and 2) were found at 62.5% and 29.1% with SA and SB, respectively (P<0.05). In conclusion, the vitrification of alpaca embryos with the ethylene glycol:sucrose solution results in better post-thaw outcomes than the ethylene glycol:sucrose:glycerol. Further experiments with embryo transfer are needed.
This research was funded by FONDECYT project no. 149-2017.
65 Co-culture of porcine epithelial oviductal cells and invitro-produced embryos: Effect on embryo development and quality
Authors: Lorenzo M. S. , Teplitz G. M. , Cruzans P. R. , Luchetti C. G. , Ghersa J. , Lombardo D. M.
Published: January 2021

The oviduct is involved in many reproductive functions, including early embryo development. The epithelial cells that cover the oviduct produce oviducal fluid and could be used to recreate the invivo environment into which embryo development takes place. This study aimed to evaluate the co-culture of porcine embryos with a monolayer of porcine oviducal epithelial cells (POEC) and its effect on embryo development and quality. The POEC were obtained by pressing the isthmus (from diestrus sow oviducts) using slides and performing 3 cycles of vortexing and decanting in DMEM-F12 medium. Passage 1 cells were used for these experiments (POEC-1). Oocytes were obtained from follicular aspiration of slaughterhouse ovaries. Oocytes were invitro matured for 44h in TCM-199 supplemented with human menopausal gonadotrophin and cyclic AMP during the first 22h. Invitro fertilization was performed with 17°C-refrigerated boar semen for 4h in 100-µL drops of TCM-199 with caffeine, bovine serum albumin, sodium lactate, and sodium pyruvate (20 denuded oocytes per drop, 1×106 spermatozoa mL−1). Presumptive zygotes were washed and randomly assigned to one of the following groups for invitro culture: control (50-µL drop of NCSU-23 with sodium pyruvate and lactate), POEC-1 (same as the control+POEC-1 50 000 cells mL−1), POEC-1+FBS (same as the control+POEC-1 50 000 cells mL−1 and 2.5% of fetal bovine serum). Culture conditions were 7% O2, 5% CO2, 39°C, and humidity. On Day 2, the cleavage rate was recorded, and embryos were transferred to NCSU-23 drops with glucose and without cells. The blastocyst rate was recorded on Day 7. Embryo quality was assessed by counting the number of cells per blastocyst (Hoechst) and the apoptosis index (TUNEL-positive cells/total cells). Co-culture with POEC-1 significantly increased the blastocyst rate (control: 14%; POEC-1+FBS: 10%; POEC-1: 28%; P<0.05 Chi-squared test) and allowed embryo hatching (control: 0; POEC-1+FBS: 22.2%; POEC-1: 7; P<0.05 Chi-squared test). However, there was no significant difference in the number of cells per blastocyst (control: 58.6±6; POEC-1+FBS: 50.3±3.7; POEC-1: 50.6±4.8; nonparametric ANOVA) or in the apoptosis index (control: 8.1; POEC+FBS 8.3; POEC: 7.4; nonparametric ANOVA). The use of POEC-1 during the first 2 days of embryo culture enhanced embryo development and improved culture conditions, allowing embryo hatching. The effect on embryo development could be due to an effect of POEC itself or the effect of feeder cells. Other parameters of embryo quality should be evaluated in the future.
73 Use of embryo transfer technology to salvage the germplasm of elite dromedary camels (Camelus dromedarius) infected with brucellosis
Authors: Abouhefnawy H. A. , Wani N. A.
Published: January 2021

The present study was conducted to evaluate the potential of embryo transfer technology to salvage invivo-produced embryos from elite dromedary camels infected with brucellosis without transmission of the pathogen to the recipients or offspring. Ten elite racing champions who tested positive for brucella comprised the experimental group, whereas 3 donors negative for brucella acted as the control. Each donor animal received a combination of 2500IU of equine chorionic gonadotrophin (eCG; Folligon; Intervet), given as a single intramuscular injection on Day 1 of the treatment protocol, and 400mg of pFSH (Folltropin; Bioniche), injected twice daily in declining doses of 2×80mg, 2×60mg, 2×40mg, and 2×20mg over 4 days, also beginning on Day 1. They were mated with a fertile bull on the 11th day after the start of treatment. The donors of the group 1 received a combination of tetracycline, and streptomycin on alternate days for 2 weeks before mating with a fertile male. An injection of 20µg of gonadotrophin-releasing hormone (Receptal, Intervet) was given to them immediately after mating to induce ovulation. The embryos were collected by the non-surgical method on Day 7 day after ovulation as per the guidelines published by IETS. All embryos were washed at least 3 times in holding medium supplemented with antibiotics and then transferred individually into the left uterine horn of synchronized recipients. All recipients and calves born were tested for brucellosis every 3 weeks. The data were analysed using a two-sample t-test (Minitab statistical software, Minitab Ltd.). Results are shown in Table 1. No difference was observed in the number of embryos collected per flushing and pregnancies established at Day 60. The proportion of pregnancies reaching term from the total number of embryos transferred and from the pregnancies established on Day 60 did not differ from embryos obtained from brucella-infected and control donors. All recipients tested negative for brucellosis during their gestation and until weaning. All calves born were also negative for brucellosis on birth and until weaning and handing over to clients. In conclusion, this is the first study in camels wherein we have demonstrated that invivo-produced embryos from elite dromedary females infected with brucellosis could be collected and transferred to synchronized recipients without transmitting the pathogen to the recipients or offspring.

Table 1.
Pregnancies established from invivo-produced embryos collected from elite dromedary camels infected with brucellosis

Donor group (N)
Total number of flushings
No. of embryos collected per flushing (n±s.e.m.)
Pregnancies on Day 60 (% mean±s.e.m.)
Pregnancies reaching term (% mean±s.e.m.) from:

Embryos transferred
Pregnancies on Day 60

Brucella (10)
30
5.4±0.6
55.1±2.6
44.4±2.3
83.2±3.6

Control (3)
6
5.3±0.6
65.7±6.3
53.3±6.8
80.9±7.7

P-value

0.969
0.173
0.262
0.797