Despite rigorous vaccination protocols, calf morbidity is the primary contributor to economic loss in the calf sector of the dairy industry. Melatonin has modulated immune response in other mature animal species. We hypothesized that exogenous melatonin may improve the cellular response to vaccination in dairy calves.
View Article and Find Full Text PDFEffects of a nutritional packet strategically offered to calf-fed system steers on growth performance, nutrient digestibility, feeding behavior, ruminal variables, and carcass characteristics were evaluated. Angus crossbred steer-calves ( = 60; body weight [BW] = 234 ± 4 kg) were used in a randomized complete block design (block = BW) and stratified into two treatments: 1) control; and 2) 30 g/steer-daily (dry matter [DM] basis) of a nutritional packet containing (steer-daily basis): Live yeast (; 1.7 × 10 CFU), vitamin C (Ascorbic acid, 162 mg), vitamin B1 (thiamin hydrochloride, 400 mg), sodium chloride (2.
View Article and Find Full Text PDFBacteriological characterization of bovine liver abscesses has been accomplished by cultural methods but DNA methods are still needed, as many bacteria are not conducive to laboratory culture. In addition to this gap in research, there have been no studies which identify the bacterial presence within healthy, non-abscessed liver tissue. The objective of this study was to compare the bacteriome of both abscessed and non-abscessed bovine livers in an observational case-control study design.
View Article and Find Full Text PDFDespite the regular use of feed-grade macrolide-antibiotics, bovine liver abscesses persist, representing a financial burden to pre- and post-mortem sectors of the beef industry. An immunoglobulin-Y () additive developed to target and was evaluated for the control of liver abscesses. Research is needed for the impact of liver abscess severity as well as abscess duration on steer performance and carcass characteristics.
View Article and Find Full Text PDFCondensed tannins (CT) might improve animal and system-level efficiency due to enhanced protein efficiency and reduced CH4. This study evaluated the impact of quebracho tannin (QT) extract fed at 0%, 1.5%, 3%, and 4.
View Article and Find Full Text PDFMicrobiol Resour Announc
December 2019
As an opportunistic pathogen, is involved in a wide spectrum of nosocomial infections. phages may prove useful as therapeutics for treating infections caused by multidrug-resistant strains. Here, we report the complete genome sequence of siphophage Sazh, which is closely related to phages T1 and TLS.
View Article and Find Full Text PDFThe objective of this trial was to determine the benefits of supplementing active dried yeast (ADY; 3 × 1010 CFU/d of Saccharomyces cerevisiae) in diets of growing and finishing steers on ruminal pH and liver health, and evaluate the relationship of these variables with performance traits. Growing beef steers (n = 120) were blocked by weight (i.e.
View Article and Find Full Text PDFThe use of active dried yeast (ADY) in the diets of feedlot steers may improve feed efficiency, growth performance, and reduce days on feed. Strategic timing of ADY inclusion in the diet may increase feed conversion or aid in the dietary transition from growing to finishing diets. One hundred twenty steers, blocked by weight, were fed four diets for 164 d: grower (70 d), first transition diet (7 d), second transition diet for (7 d), and finisher (80 d) in a GrowSafe System.
View Article and Find Full Text PDFThe objective of this trial was to determine the effects of supplementing active dried yeast (ADY) in the diets of finishing steers on energy and nitrogen metabolism and ruminal pH characteristics under thermoneutral (TN) or heat-stressed (HS) conditions. Eight British cross steers received 1 of 2 treatments (TRT) [either a control finishing diet (CON) or supplemented with 3 g/d of ADY] under 1 of 2 temperatures [TEMP: TN = 18 ± 0.55 °C and 20 ± 1.
View Article and Find Full Text PDFIonophores and antibiotics have been shown to decrease ruminal methanogenesis both in vitro and in vivo but have shown little evidence toward a sustainable means of mitigation. Feed additive rotation was proposed and investigated for methane, VFA, and microbial population response. In the present study, cannulated steers ( = 12) were fed a moderate-forage basal diet in a Calan gate facility for 13 wk.
View Article and Find Full Text PDFA method to measure the optical response across the surface of a phase-only liquid crystal on silicon device using binary phase gratings is described together with a procedure to compensate its spatial optical phase variation. As a result, the residual power between zero and the minima of the first diffraction order for a binary grating can be reduced by more than 10 dB, from -15.98 dB to -26.
View Article and Find Full Text PDFIt is shown that reflective liquid crystal on silicon (LCOS) spatial light modulator (SLM) based interconnects or fiber switches that use defocus to reduce crosstalk can be evaluated and optimized using a fractional Fourier transform if certain optical symmetry conditions are met. Theoretically the maximum allowable linear hologram phase error compared to a Fourier switch is increased by a factor of six before the target crosstalk for telecom applications of -40 dB is exceeded. A Gerchberg-Saxton algorithm incorporating a fractional Fourier transform modified for use with a reflective LCOS SLM is used to optimize multi-casting holograms in a prototype telecom switch.
View Article and Find Full Text PDFA technique of cross talk mitigation developed for liquid crystal on silicon spatial light modulator based optical interconnects and fiber switches is demonstrated. By purposefully introducing an appropriate aberration into the system, it is possible to reduce the worst-case cross talk by over 10 dB compared to conventional Fourier-transform-based designs. Tests at a wavelength of 674 nm validate this approach, and show that there is no noticeable reduction in diffraction efficiency.
View Article and Find Full Text PDFTunable materials with high anisotropy of refractive index and low loss are of particular interest in the microwave and terahertz range. Nematic liquid crystals are highly sensitive to electric and magnetic fields and may be designed to have particularly high birefringence. In this paper we investigate birefringence and absorption losses in an isothiocyanate based liquid crystal (designed for high anisotropy) in a broad range of the electromagnetic spectrum, namely 0.
View Article and Find Full Text PDFPlatelet basic protein (PBP) and several of its derivatives are known to express a wide range of biological characteristics. It is the precursor of connective tissue activating peptide (CTAP-III), beta thromboglobulin (beta-TG) and neutrophil activating peptide (NAP-2), which is the proteolytic derived end product. The temporal ocular expression of the chemokine PBP before and during corneal infection over several days by Pseudomonas aeruginosa was examined by immunohistochemistry.
View Article and Find Full Text PDFWe discuss some fundamental characteristics of a phase-modulating device suitable to holographically project a monochrome video frame with 1280 x 720 resolution. The phase-modulating device is expected to be a liquid crystal over silicon chip with silicon area similar to that of commercial devices. Its basic characteristics, such as number of pixels, bits per pixel, and pixel dimensions, are optimized in terms of image quality and optical efficiency.
View Article and Find Full Text PDFFerroelectric liquid crystals can be optimized for speed, but such materials tend to have small switching angles and consequently low contrast in the smectic A(*) phase. We describe a method whereby such a low-contrast but fast-switching effect can be enhanced, in theory giving the same contrast as a material with a switching angle of 22.5 degrees .
View Article and Find Full Text PDFA nematic liquid crystal spatial light modulator used as a phase-modulating device and operating in the reflective mode is analyzed using three-dimensional modeling. Two configurations, which differ in their electrode placement relative to a fixed quarter-wave plate, are considered across a range of steering directions, with the grating conformal and in some cases oblique to the pixel grid. For each steering direction the sensitivity of the diffraction orders to the polarization state of the incident wavefront is studied.
View Article and Find Full Text PDFDye-doped nematic liquid crystals (LCs) are studied as materials for single-layer optically addressed spatial light modulators. The dopant is 2,5-azo-substituted anthraquinone (ASAQ) dye. The resolution in the ASAQ-doped LC systems does not depend on the device thickness (in the 5-125 microm range).
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
October 2006
The next generation of applications for liquid crystal (LC) over silicon technology will be non-display oriented systems such as adaptive optical interconnects, optical switches and optical image processors. These new non-display applications have a different set of material parameters, which means that existing display-based materials are not entirely optimal. This is particularly the case when the application is driven by phase modulation at high frame rates (more than 1 kHz).
View Article and Find Full Text PDFActive alignment of a 1 x 8 free-space optical switch was studied experimentally. Optical signals, carried on single-mode fibers, were switched by a ferroelectric liquid-crystal-on-silicon spatial light modulator. Continuous measurement of the in-coupled power to the fibers provided feedback for the switch control.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
January 2001
An analysis of dynamic phase-only holograms, described by fractional notation and recorded onto a pixelated spatial light modulator (SLM) in a reconfigurable optical beam-steering switch, is presented. The phase quantization and arrangement of the phase states and the SLM pixelation and dead-space effects are decoupled, expressed analytically, and simulated numerically. The phase analysis with a skip-rotate rule reveals the location and intensity of each diffraction order at the digital replay stage.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
January 2001
Reconfigurable optical interconnects constructed by recording dynamic holograms onto spatial light modulators may be crucial elements in all-optical networks. The extremely low cross-talk level of such free-space holographic switches was shown by an analytic approximation and verified experimentally. The fiber-to-fiber switch utilizes the spatial filtering properties of single-mode fibers, and its cross-talk noise is limited to the sidelobe power as a result of diffraction of the clipped Gaussian beam at the hologram aperture edges, provided that all higher orders are avoided.
View Article and Find Full Text PDFWe examined the posthatch chick retina for the frequency of occurrence of localization and colocalization of four amino acid transmitter candidates: glutamate (Glu), aspartate (Asp), gamma aminobutyric acid (GABA), and glycine (Gly) using postembedding methods. We support previous studies of Glu, Asp, GABA, and Gly localization in the direct and indirect functional pathways of the chick retina and extend these studies with new qualitative and quantitative observations. We found that photoreceptors show distinct cellular immunoreactivity for both Glu (Glu+) and Asp+, but not for Gly (Gly-) or GABA.
View Article and Find Full Text PDFPrevious work has shown that nucleosides produce apoptosis in sympathetic ganglion (SG) cells in vitro. The present study examined the effects of nucleosides on the development of the chick embryo in vivo with special attention to the SG and the optic tectum of the central nervous system. In the presence of an adenosine deaminase inhibitor, adenosine and 2'-deoxyadenosine (2'-dAdo) produced different toxicity patterns: both adenosine and 2'-dAdo were toxic to E3 embryos, but only 2'-dAdo was toxic at later stages (E6 1/2, E11).
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