11351 research outputs found
Sort by
Effect of copulation on estrus duration, LH response, and ovulation in Boer goats
No full textThe objectives of this investigation were to determine the effect of copulation on estrus duration, LH response and ovulation in Boer goats. A controlled randomized study, with two replicates, in which does were divided at each replicate in treatment (COP; n = 12) and control (CON; n = 12) groups was performed. All the does were pluriparous and estrus synchronized with CIDR (progesterone 300 mg) maintained in the vagina for seven days, and received 50 μg of GnRH at device insertion and 5 mg of natural prostaglandin F-2 im at CIDR removal. The COP group received two copulas within the first 4 h of estrus onset, and the CON group was only permitted to be mounted. Estrus was detected twice a day during the first 24 h after pessary removal and then every 4 h by using bucks with canvas apron as teasers, led by leash for 96 h. Blood was collected during all the estrus period after each estrus detection and analyzed for LH by radioimmunoassay (RIA). In addition, at the second replicate ovulation time and number of ovulations were also monitored by transrectal ultrasonography using a linear 7.5 MHz probe beginning 24 h after estrus onset and repeated every 4 h until all the preovulatory follicles disappeared. Estrus onset was 36.7 ± 10.5 h and 35.5 ± 13.6 h for CON and COP groups, respectively (P = 0.82). Estrus duration for the same groups was 40.3 ± 9.9 h and 28.3 ± 4.7 h, respectively (P = 0.001). The LH peak time for the CON group was 17.7 ± 6.3 h, and for the COP group, it was 10.9 ± 2.6 h (P = 0.004). The LH peak magnitude for the same groups was 31.5 ± 16.2 ng/mL and 34.9 ± 20.7 ng/mL, respectively (P = 0.34). The LH peak duration was not different between groups (CON: 7.3 ± 1.6 h versus COP: 7.2 ± 2.4 h; P = 0.94). The first ovulation time for CON and COP groups was 33.7 ± 3.9 h and 29.1 ± 3.2 h (P = 0.05), and the last ovulation time for the same groups was 37.7 ± 3.9 h and 32.6 ± 2.5 h, respectively (P = 0.02). The overall time from LH peak to ovulation was 18.6 ± 4.8 h without differences between groups (CON: 16.3 ± 5.6 h versus COP: 20.6 ± 3.3 h; P = 0.15). The number of ovulations for the CON group was 2.2 ± 0.4, and for COP group, it was 2.1 ± 0.4 (P = 0.96). It was concluded that copulation reduced estrus duration and hastened LH peak and ovulation in Boer goats
Fake news detection enhancement with data imputation
No full textRaw datasets collected for fake news detection usually contain some noise such as missing values. In order to improve the performance of machine learning based fake news detection, a novel data preprocessing method is proposed in this paper to process the missing values. Specifically, we have successfully handled the missing values problem by using data imputation for both categorical and numerical features. For categorical features, we imputed missing values with the most frequent value in the columns. For numerical features, the mean value of the column is used to impute numerical missing values. In addition, TF-IDF vectorization is applied in feature extraction to filter out irrelevant features. Experimental results show that Multi-Layer Perceptron (MLP) classifier with the proposed data preprocessing method outperforms baselines and improves the prediction accuracy by more than 15%
Rotation and radiation effects on MHD flow past an inclined plate with variable wall temperature and mass diffusion in the presence of Hall current
Get PDFIn the present paper, rotation and radiation effects on unsteady MHD flow passed an inclined plate with variable wall temperature and mass diffusion in the presence of Hall current has been studied. The fluid considered is viscous, incompressible and electrically conducting. Earlier, we have studied unsteady MHD flow past an impulsively started inclined plate with variable temperature and mass diffusion. In that study we had analyzed the effect of Hall current (2016). We obtained the results which were in agreement with the desired flow phenomenon. To study further, we are changing the model by considering radiation and rotation effect on fluid. The plate temperature and the concentration level near the plate increase linearly with time. The model contains equations of motion, diffusion equation and equation of energy. The governing system of partial differential equations is transformed to dimensionless equations by using non-dimensional variables. To analyze the solution of the model, desirable sets of the values of the parameters have been considered. The governing equations involved in the flow model are solved by the Laplace-transform technique. The results obtained have been analyzed with the help of graphs drawn for different parameters. The numerical values obtained for the drag at boundary and Nusselt number have been tabulated. We found that the values obtained for velocity, concentration and temperature are in concurrence with the actual flow of the fluid. The results of the study may find applications in the field related to the solar physics dealing with the solar cycle, the sunspot development, the structure of rotating magnetic stars etc
The Circular Restricted Four-body Problem With Triaxial Primaries and Variable Infinitesimal Mass
Get PDFThis paper investigates the circular restricted four-body problem in which three primaries are taken as triaxial rigid body which are placed at the vertices of an equilateral triangle and the fourth infinitesimal body is varying its mass with time. We used the Jeans law to determine equations of motion and then evaluated the Jacobi integral. In the next section, we have performed the computational work to draw the graphs of the equilibrium points in different planes, zero velocity curves, surfaces and the Newton-Raphson basins of attraction with the variations of the triaxiality parameters. Finally, we have examined the linear stability of the equilibrium points with the help of Meshcherskii space-time inverse transformation and found that all the equilibrium points are unstable
Assessing potential climate change impacts on irrigation requirements of major crops in the brazos headwaters Basin, Texas
No full textIn order for the agricultural sector to be sustainable, farming practices and management strategies need to be informed by site-specific information regarding potential climate change impacts on irrigation requirements and water budget components of different crops. Such information would allow managers and producers to select cropping systems that ensure efficient use of water resources and crop productivity. The major challenge in understanding the link between cropping systems and climate change is the uncertainty of how the climate would change in the future and lack of understanding how different crops would respond to those changes. This study analyzed the potential impact of climate change on irrigation requirements of four major crops (cotton, corn, sorghum, and winter wheat) in the Brazos Headwaters Basin, Texas. The irrigation requirement of crops was calculated for the baseline period (1980-2010) and three projected periods: 2020s (2011-2030), 2055s (2046-2065), and 2090s (2080-2099). Daily climate predictions from 15 general circulation models (GCMs) under three greenhouse gas (GHG) emission scenarios (B1, A1B, and A2) were generated for three future periods using the Long Ashton Research Station-Weather Generator (LARS-WG) statistical downscaling model. Grid-based (55 grids at ~38 km resolution) irrigation water requirements (IRRs) and other water budget components of each crop were calculated using the Irrigation Management System (IManSys) model. Future period projection results show that evapotranspiration (ET) and IRR will increase for all crops, while precipitation is projected to decrease compared with the baseline period. On average, precipitation meets only 25-32% of the ET demand, depending on crop type. In general, projections from almost all GCMs show an increase in IRR for all crops for the three future periods under the three GHG emission scenarios. Irrigation requirement prediction uncertainty between GCMs was consistently greater in July and August for corn, cotton, and sorghum regardless of period and emission scenario. However, for winter wheat, greater uncertainties between GCMs were observed during April and May. Irrigation requirements show significant variations across spatial locations. There was no consistent spatial trend in changes of IRR for the four crops. A unit change in precipitation is projected to affect IRR differently depending on the crop type
Global Stability of Ebola Virus Disease Model with Contact Tracing and Quarantine
Get PDFThis study considers a deterministic model of Ebola Virus Disease (EVD) incorporating contact tracing and quarantine as interventions. The model analyze the existence and stability of Disease-Free Equilibrium (DFE) and Endemic Equilibrium (EE) states. The local stability of EE is established using centre manifold theorem. The global stability of the two equilibrium states are obtained by constructing the Lyapunov function. Numerical simulations are carried out to examine the impact of contact tracing and quarantine measures on the transmission dynamics of EVD. The result indicates that EVD could be eliminated faster when contact tracing and quarantine measures are implemented together
An Accelerate Process for the Successive Approximations Method In the Case of Monotonous Convergence
Get PDFWe study an iterative process to accelerate the successive approximations method in a monotonous convergence framework. It consists in interrupting the sequence of the successive approximations method produced at the kth iteration and substituting it by a combination of the element of the sequence produced at the iterate k + 1 and an extrapolation vector. The latter uses a parameter which can be calculated mathematically. We illustrate numerically this process by studying a freeboundary problems class
Cilia Transport for Micropolar Fluid Through a Uniform Cylindrical Tube
Get PDFThe aim of this work is to study the role that the cilia motion plays in the transport of a micropolar fluid in a uniform cylindrical tube. The transport due to systems of beating cilia is responsible for the transport of bio-fluids in numerous physiological processes. Cylindrical coordinates are used to formulate the system of equations with the suitable boundary conditions governing the flow. Such system is then simplified through considering the long wavelength and low Reynolds number assumptions. Solutions are found for the velocity components, the pressure gradient, and the stream function which include many parameters such as the cilia length parameter, the eccentricity parameter of the elliptical motion and the wave number. The results shows that the pumping machinery functions more efficiently to push ahead micropolar fluid than Newtonian fluid. The obtained results may help to understand more the processes of the transport of bio-fluids in human body