108,893 research outputs found
Immunological profiles of Bos taurus and Bos indicus cattle infested with the cattle tick, Rhipicephalus (Boophilus) microplus
No full textThe cattle tick, Rhipicephalus (Boophilus) microplus, is a major threat to the improvement of cattle production in tropical and subtropical countries worldwide. Bos indicus cattle are naturally more resistant to infestation with the cattle tick than are Bos taurus breeds, although considerable variation in resistance occurs within and between breeds. It is not known which genes contribute to the resistant phenotype, nor have immune parameters involved in resistance to R. microplus been fully described for the bovine host. This study was undertaken to determine whether selected cellular and antibody parameters of the peripheral circulation differed between tick-resistant Bos indicus and tick-susceptible Bos taurus cattle following a period of tick infestations. This study demonstrated significant differences between the two breeds with respect to the percentage of cellular subsets comprising the peripheral blood mononuclear cell population, cytokine expression by peripheral blood leukocytes, and levels of tick-specific immunoglobulin G1 (IgG1) antibodies measured in the peripheral circulation. In addition to these parameters, the Affymetrix bovine genome microarray was used to analyze gene expression by peripheral blood leukocytes of these animals. The results demonstrate that the Bos indicus cattle developed a stabilized T-cell-mediated response to tick infestation evidenced by their cellular profile and leukocyte cytokine spectrum. The Bos taurus cattle demonstrated cellular and gene expression profiles consistent with a sustained innate, inflammatory response to infestation, although high tick-specific IgG1 titers suggest that these animals have also developed a T-cell response to infestation
Complete mitochondrial genomes of Bos taurus and Bos indicus provide new insights into intraspecies variation taxonomy and domestication
No full textThe taurine and zebuine cattle breeds comprise the majority of the world cattle population but their taxonomic status is still controversial. The two forms of cattle are currently classified as Bos taurus and Bos indicus species and are differentiated primarily by the presence or absence of a hump. However, these two species hybridize readily, producing fully fertile offspring. We have determined and analyzed complete B. taurus and B. indicus mitochondrial genome sequences to investigate the extent of sequence divergences and to study their taxonomic status by molecular dating. The sequences encompassed 16,338 and 16,339 nucleotides, respectively, and differed at 237 positions. Estimated divergence times indicated that the two cattle lineages separated 1.7-2.0 million years ago. Combined phylogenetic analyses of 18 new and 130 previously reported extant B. taurus and B. indicus control region sequences with data from 32 archaeological specimens of the extinct wild aurochs (Bos primigenius) identified four major maternal lineages. B. primigenius haplotypes were present in all but the B. indicus lineage, and one B. taurus sequence clustered with B. primigenius P haplotypes that were not previously linked with domestic cattle. The B. indicus cluster and a recently reported new B. primigenius haplotype that represents a new lineage were approximately equidistant from the B. taurus cluster. These data suggest domestications from several differentiated populations of B. primigenius and a subspecies status for taurine (B. primigenius taurus) and zebuine (B. primigenius indicus) cattle.S. Hiendleder, H. Lewalski, A. Jank
Joshua Davis: Author of Spare Parts
No full textCitation: K-State First (2016). Joshua Davis: Author of Spare Parts [Flier]. Manhattan, Kansas: K-State First.Flyer advertising Joshua Davis's author talk at Kansas State University
Steven Johnson Author Talk Poster
No full textK-State Book NetworkA poster advertising an author talk by Steven Johnson at Kansas State University on September 3, 2014. Steven Johnson's book "The Ghost Map" was the 2014-2015 common book
Numerical BOS of Bunsen premixed lean H2-air flame
No full textLAUREA MAGISTRALEL'idrogeno, un elemento vitale nella ricerca di energia sostenibile, rimane complesso nelle sue dinamiche di combustione, svelando un ambito dove la nostra comprensione, seppur significativa, rimane incompleta. Questo studio esplora la combustione dell'idrogeno attraverso un approccio integrato, combinando la modellizzazione computazionale della dinamica dei fluidi (CFD) con tecniche di validazione sperimentale. L'obiettivo è sviluppare un modello di fiamma CFD accoppiato con la tecnica numerica Background-Oriented Schlieren (BOS) per simulare e convalidare i risultati sperimentali.
Metodologicamente, un modello di simulazione a freddo in 3D utilizzando il modello di turbolenza SST k-ω in FLUENT ANSYS costituisce la base. Successivamente, viene costruito un modello di simulazione della fiamma assiale simmetrico-2D incorporando il meccanismo globale a un passo di Verna e il Concetto di Dissipazione degli Eddy (EDC). Questi modelli forniscono dati essenziali per simulare la tecnica numerica BOS.
Le simulazioni numeriche BOS producono mappe di temperatura, densità e indice di rifrazione, facilitati dall'adattamento dell'Algoritmo ARAP di Siptkens. Le simulazioni BOS in avanti generano mappe di spostamento, che a loro volta fungono da dati di input per le simulazioni BOS inverse, producendo nuove mappe di parametri.
I risultati indicano che il modello CFD potrebbe rappresentare con precisione i risultati sperimentali, convalidando la sua efficacia nel catturare le complessità delle dinamiche di combustione dell'idrogeno. Questa importanza si estende all'utilità del modello CFD per convalidare misurazioni sperimentali ed ottimizzare configurazioni sperimentali, riducendo così le incertezze associate alle tecniche impiegate.Hydrogen, a vital element in the pursuit of sustainable energy, remains intricate in its combustion dynamics, unveiling a domain where our understanding, while significant, remains incomplete. This study explores hydrogen combustion through an integrated approach, combining computational fluid dynamics (CFD) modeling with experimental validation techniques. The objective is to develop a CFD flame model coupled with numerical Background-Oriented Schlieren (BOS) technique to both simulate and validate experimental results.
Methodologically, a 3D cold simulation model using the SST k-ω turbulence model in FLUENT ANSYS lays the groundwork. Subsequently, an axial symmetrical-2D flame simulation model incorporating Verna's one-step global mechanism and Eddy Dissipation Concept (EDC) is constructed. These models provide essential data for simulating the numerical BOS technique.
The numerical BOS simulations yield temperature, density, and refractive index maps, facilitated by the adaptation of Siptkens's ARAP Algorithm. Forward BOS simulations generate displacement maps, which, in turn, serve as input data for Reverse BOS simulations, yielding new parameter maps.
Findings indicate that the CFD model could accurately represent experimental results, validating its efficacy in capturing the complexities of hydrogen combustion dynamics. This significance extends to the utility of the CFD model in validating experimental measurements and optimizing experimental setups, thereby reducing uncertainties associated with the techniques employed
Direction change of fluid particles in confined two-dimensional turbulence
No full textThe directional change of a fluid particle can be measured by the angle between two subsequent particle displacement increments. At small values of the time-increment the so-defined angle is proportional to the curvature of the trajectory. At large values this coarse-grained curvature should be affected by the presence of solid no-slip walls around the flow domain. We compare homogeneous and confined two-dimensional turbulent flows and show that the PDF of the angle is indeed strongly modified by the presence of walls
Genome sequencing of the extinct Eurasian wild aurochs, Bos primigenius, illuminates the phylogeography and evolution of cattle
No full textBackground
Domestication of the now-extinct wild aurochs, Bos primigenius, gave rise to the two major domestic extant cattle taxa, B. taurus and B. indicus. While previous genetic studies have shed some light on the evolutionary relationships between European aurochs and modern cattle, important questions remain unanswered, including the phylogenetic status of aurochs, whether gene flow from aurochs into early domestic populations occurred, and which genomic regions were subject to selection processes during and after domestication. Here, we address these questions using whole-genome sequencing data generated from an approximately 6,750-year-old British aurochs bone and genome sequence data from 81 additional cattle plus genome-wide single nucleotide polymorphism data from a diverse panel of 1,225 modern animals.
Results
Phylogenomic analyses place the aurochs as a distinct outgroup to the domestic B. taurus lineage, supporting the predominant Near Eastern origin of European cattle. Conversely, traditional British and Irish breeds share more genetic variants with this aurochs specimen than other European populations, supporting localized gene flow from aurochs into the ancestors of modern British and Irish cattle, perhaps through purposeful restocking by early herders in Britain. Finally, the functions of genes showing evidence for positive selection in B. taurus are enriched for neurobiology, growth, metabolism and immunobiology, suggesting that these biological processes have been important in the domestication of cattle.
Conclusions
This work provides important new information regarding the origins and functional evolution of modern cattle, revealing that the interface between early European domestic populations and wild aurochs was significantly more complex than previously thought
Experimental Legal Studies on Perceived Procedural Justice and Trust in Law and Society
No full textAkkermans, A.J. [Promotor]Bos, K. van den [Promotor
LIMITS OF WEIGHTED SPLINES BASED ON PIECEWISE-CONSTANT WEIGHT-FUNCTIONS
No full textWe study limits of weighted splines when the weight function is piecewise constant
ON THE MATRIX [(XI-XJ)3] AND THE CUBIC SPLINE CONTINUITY EQUATIONS
No full textWe discuss the relation bewteen the cubic spline continuity equations and the matrix of distances cubed
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