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71.
72.
Multimedia Tools and Applications - Texture images are those where the focus of the analysis is on the spatial arrangement of pixels (primitives or textons) rather than on particular objects in the... 相似文献
73.
Jannelle Morrison David L. Renaud Kathryn J. Churchill Joao H.C. Costa Michael A. Steele Charlotte B. Winder 《Journal of dairy science》2021,104(6):7177-7194
Automated milk feeders (AMF) are computerized systems that provide producers with a tool that can be used to more efficiently raise dairy calves and allow for easier implementation of a high plane of nutrition during the milk feeding phase. Automated milk feeders also have the ability to track individualized behavioral data, such as milk consumption, drinking speed, and the number of rewarded and unrewarded visits to the feeder, that could potentially be used to predict disease development. The objective of this scoping review was to characterize the body of literature investigating the use of AMF data to predict morbidity and mortality in dairy calves during the preweaning stage. This review lists the parameters that have been examined for associations with disease in calves and identify discrepancies found in the literature. Five databases and relevant conference proceedings were searched. Eligible studies focused on the use of behavioral parameters measured by AMF to predict morbidity or mortality in preweaned dairy calves. Two reviewers independently screened titles and abstracts from 6,675 records identified during the literature search. After title and abstract screening, 382 studies were included and then assessed at the full-text level. Of these, 56 studies fed calves using an AMF and provided some measure of morbidity or mortality. Thirteen examined AMF parameters for associations with morbidity or mortality. The studies were completed in North America (n = 6), Europe (n = 6), and New Zealand (n = 1). The studies varied in sample size, ranging from 30 to 1,052 calves with a median of 100 calves. All 13 studies included enteric disease as an outcome and 11 studies evaluated respiratory disease. Of the studies measuring enteric disease, 8 provided disease definitions (n = 8/13, 61.2%); however, for respiratory disease, only 5 provided a disease definition (n = 5/11, 45.5%). Disease definitions and thresholds varied greatly between studies, with 10 using some form of health scoring. When evaluating feeding metrics as indicators of disease, all 13 studies investigated milk consumption and 6 and 7 studies investigated drinking speed and number of rewarded and unrewarded visits, respectively. Overall, this scoping review identified that daily milk consumption, drinking speed, and rewarded and unrewarded visits may provide insight into early disease detection in preweaned dairy calves. However, the disparity in reporting of study designs and results between included studies made comparisons challenging. In addition, to aid with the interpretation of studies, standardized disease outcomes should be used to improve the utility of this primary research. 相似文献
74.
Augustine K. Obour Maria L. Silveira Joao M. B. Vendramini Lynn E. Sollenberger George A. O’Connor 《Nutrient Cycling in Agroecosystems》2011,91(2):207-217
Spodosols in Florida exhibit a unique hydrology including a fluctuating water table that can often reach the surface horizon
during the summer months. This paper evaluated the effects of fluctuating water table on P fluxes and availability in a typical
Florida Spodosol. The study was conducted on an established bahiagrass (Paspalum notatum Flügge) pasture grown on a Smyrna sand (sandy, siliceous, hyperthermic Aeric Alaquods). Phosphorus fluxes were measured using
suction cup lysimeters installed at depths of 15, 30, 60, 90, and 150 cm. The 15- and 30-cm deep lysimeters were located above
the spodic (Bh) horizon, whereas the remaining lysimeters (60-, 90- and 150-cm) were below the Bh horizon. A pressure transducer
was installed at the center of the experimental site to monitor changes in water table depth. Two anion exchange membranes
(2 × 6 cm) were buried in each plot at a 15-cm depth to estimate in situ P availability. During the 2-year study, leachate
P concentrations in the lysimeters above the Bh horizon increased as water tables rose in the months of August and September.
Conversely, P concentration measured in the lysimeters below the Bh horizon remained relatively constant (0.02 mg L−1). Soil P availability also increased (from 3.2 μg cm−2 in June to 9.2 μg cm−2 in August) in response to rising water table. Results showed that the fluctuating water table conditions experienced during
the summer months in Florida cause upward flux of P from the Bh horizon, which increased soil P availability and susceptibility
to off-site transport. 相似文献
75.
Desmarais JA Demers SP Suzuki J Laflamme S Vincent P Laverty S Smith LC 《Reproduction (Cambridge, England)》2011,141(3):321-332
Although putative horse embryonic stem (ES)-like cell lines have been obtained recently from in vivo-derived embryos, it is currently not known whether it is possible to obtain ES cell (ESC) lines from somatic cell nuclear transfer (SCNT) and parthenogenetic (PA) embryos. Our aim is to establish culture conditions for the derivation of autologous ESC lines for cell therapy studies in an equine model. Our results indicate that both the use of early-stage blastocysts with a clearly visible inner cell mass (ICM) and the use of pronase to dissect the ICM allow the derivation of a higher proportion of primary ICM outgrowths from PA and SCNT embryos. Primary ICM outgrowths express the molecular markers of pluripotency POU class 5 homeobox 1 (POU5F1) and (sex determining region-Y)-box2 (SOX2), and in some cases, NANOG. Cells obtained after the passages of PA primary ICM outgrowths display alkaline phosphatase (AP) activity and POU5F1, SOX2, caudal-related homeobox-2 (CDX2) and eomesodermin (EOMES) expression, but may lose NANOG. Cystic embryoid body-like structures expressing POU5F1, CDX2 and EOMES were produced from these cells. Immunohistochemical analysis of equine embryos reveals the presence of POU5F1 in trophectoderm, primitive endoderm and ICM. These results suggest that cells obtained after passages of primary ICM outgrowths are positive for trophoblast stem cell markers while expressing POU5F1 and displaying AP activity. Therefore, these cells most likely represent trophoblast cells rather than true ESCs. This study represents an important first step towards the production of autologous equine ESCs for pre-clinical cell therapy studies on large animal models. 相似文献
76.
This work presents results with noble metal catalysts, Pt and PtRu supported on Black Pearl with a higher surface area in comparison with carbon black Vulcan XC-72R and Vulcan XC72. The nanoparticles were synthesized following the alcohol reduction method. Brunauer–Emmet–Teller (BET) surface area analysis, X-ray diffraction (XRD), energy dispersive analysis by X-rays (EDAX), and high resolution transmission electronic microscopy (TEM) experiments were carried out to characterize the materials obtained. Cyclic voltammograms (CV) of catalysts using the porous thin layer electrode technique were obtained for the catalysts surface evaluation and for methanol oxidation to check the electrocatalytic behavior of these nanocatalyst systems. 相似文献
77.
Mustapha Benkhalifa Fabien Joao Cynthia Duval Debbie Montjean Molka Bouricha Rosalie Cabry Marie-Claire Blanger Hatem Bahri Pierre Miron Moncef Benkhalifa 《International journal of molecular sciences》2022,23(21)
After more than four decades of assisted reproductive technology (ART) practice worldwide, today more than 60% of women undergoing in vitro fertilization (IVF) treatments fail to become pregnant after the first embryo transfer and nearly 20% of patients are suffering from unexplained recurrent implantation failures (RIFs) and repeated pregnancy loss (RPL). The literature reported different causes of RIF–RPL, mainly multifactorial, endometrial and idiopathic. RIF remains a black box because of the complicated categorization and causes of this physio-pathological dysregulation of implantation and pregnancy process after ovarian stimulation. Many options were suggested as solutions to treat RIF–RPL with controversial results on their usefulness. In this article, we reviewed different possible therapeutic options to improve implantation rates and clinical outcomes. Based on our experience we believe that endometrium immunomodulation after intrauterine insemination of activated autologous peripheral blood mononuclear cells (PBMCs) or platelet-rich plasma (PRP) can be a promising therapeutic solution. On the other hand, peripheral lymphocyte balance typing, specific cytokines and interleukins profiling can be proposed as predictive biomarkers of implantation before embryo transfer. 相似文献
78.
Joo Neves Miguel Sampaio Ana Sneca Susana Pereira Jos Pissarra Cludia Pereira 《International journal of molecular sciences》2021,22(19)
Adverse conditions caused by abiotic stress modulate plant development and growth by altering morphological and cellular mechanisms. Plants’ responses/adaptations to stress often involve changes in the distribution and sorting of specific proteins and molecules. Still, little attention has been given to the molecular mechanisms controlling these rearrangements. We tested the hypothesis that plants respond to stress by remodelling their endomembranes and adapting their trafficking pathways. We focused on the molecular machinery behind organelle biogenesis and protein trafficking under abiotic stress conditions, evaluating their effects at the subcellular level, by looking at ultrastructural changes and measuring the expression levels of genes involved in well-known intracellular routes. The results point to a differential response of the endomembrane system, showing that the genes involved in the pathway to the Protein Storage Vacuole and the exocyst-mediated routes are upregulated. In contrast, the ones involved in the route to the Lytic Vacuole are downregulated. These changes are accompanied by morphological alterations of endomembrane compartments. The data obtained demonstrate that plants’ response to abiotic stress involves the differential expression of genes related to protein trafficking machinery, which can be connected to the activation/deactivation of specific intracellular sorting pathways and lead to alterations in the cell ultrastructure. 相似文献
79.
Extending the constant power speed range of the brushless DC motor through dual-mode inverter control 总被引:4,自引:0,他引:4
Lawler J.S. Bailey J.M. McKeever J.W. Joao Pinto 《Power Electronics, IEEE Transactions on》2004,19(3):783-793
An inverter topology and control scheme has been developed and tested to demonstrate that it can drive low-inductance, surface mounted permanent magnet motors over the wide constant power speed range (CPSR) required in electric vehicle applications. This new controller, called the dual-mode inverter controller (DMIC) , can drive both the Permanent Magnet Synchronous Machine with sinusoidal back emf, and the brushless dc machine (BDCM) with trapezoidal emf as a motor or generator. Here we concentrate on the application of the DMIC to the operation of the BDCM in the motoring mode. Simulation results, supported by closed form analytical expressions, show that the CPSR of the DMIC driven BDCM is infinite when all of the motor and inverter loss mechanisms are neglected. The expressions further show that the ratio of high-to-low motor inductances accommodated by the DMIC is 11 making the DMIC compatible with both low- and high-inductance BDCMs. Classical hysteresis-band motor current control used below base speed is integrated with DMICs phase advance above base speed. The power performance of the DMIC is then simulated across the entire speed range. Laboratory testing of a low-inductance, 7.5-hp BDCM driven by the DMIC demonstrated a CPSR above 6:1. Current peak and rms values remained controlled below rated values at all speeds. A computer simulation accurately reproduced the results of lab testing showing that the limiting CPSR of the test motor is 8:1. 相似文献
80.
Anastrepha fraterculus (Wiedemann) females were found to deposit a water-soluble, durable, oviposition-deterring pheromone during ovipositor dragging on fruit after egg-laying. We present evidence that the occurrence of pheromone deposition after egg-laying, the amount deposited, and departure from the fruit without additional egg-laying after pheromone deposition are flexible traits inA. fraterculus, varying in expression according to fruit size and other factors. UnlikeRhagoletis, A. fraterculus males were not arrested by the pheromone. 相似文献