Search

Manual count of mitotic figures, which is determined in the tumor region with the highest mitotic activity, is a key parameter of most tumor grading schemes. It can be, however, strongly dependent on the area selection due to uneven mitotic figure distribution in the tumor section. We aimed to assess the question, how significantly the area selection could impact the mitotic count, which has a known high inter-rater disagreement. On a data set of 32 whole slide images of H&E-stained canine cutaneous mast cell tumor, fully annotated for mitotic figures, we asked eight veterinary pathologists (five board-certified, three in training) to select a field of interest for the mitotic count. To assess the potential difference on the mitotic count, we compared the mitotic count of the selected regions to the overall distribution on the slide. Additionally, we evaluated three deep learning-based methods for the assessment of highest mitotic density: In one approach, the model would directly try to predict the mitotic count for the presented image patches as a regression task. The second method aims at deriving a segmentation mask for mitotic figures, which is then used to obtain a mitotic density. Finally, we evaluated a two-stage object-detection pipeline based on state-of-the-art architectures to identify individual mitotic figures. We found that the predictions by all models were, on average, better than those of the experts. The two-stage object detector performed best and outperformed most of the human pathologists on the majority of tumor cases. The correlation between the predicted and the ground truth mitotic count was also best for this approach (0.963-0.979). Further, we found considerable differences in position selection between pathologists, which could partially explain the high variance that has been reported for the manual mitotic count. To achieve better interrater agreement, we propose to use a computer-based area selection for support of the pathologist in the manual mitotic count.

Pressure swirl nozzles are often employed in water mist fire suppression systems. In the present work, a single head full cone simplex nozzle with X-type swirl-insert and an orifice diameter of 1.2 mm is used to produce water mist. The objectives are to experimentally measure different characteristics of the spray and investigate extinction performance of diesel pool fires of size 0.1, 0.2, and 0.3 m. Discharge coefficient and spray cone angle are measured and correlations are presented as functions of Reynolds numbers (Re, based on orifice diameter). Mass flux density of the spray is measured with a patternator designed considering possible asymmetry in the spray. Droplet size and velocity distributions are measured using a particle droplet image analyser (PDIA) system for 28,850 ≤ Re ≤ 35,800 and axial distances from the nozzle (0.75 ≤ z ≤ 1.75 m). Experimentally measured droplet number distributions are characterized by modified log-normal distribution. Rosin-Rammler and modified Rosin-Rammler model are presented to predict droplet volume distributions. Correlations are presented for calculating parameters of these models in order to describe droplet size distribution (DSD) for any combination of Re and z. Relative span factor (RSF), Sauter mean diameter (SMD), and average velocity of the spray are measured. Correlations for SMD and average velocity are presented as functions of experimental variables. The extinction performances are investigated through video recording for 28,850 ≤ Re ≤ 35,800 and various vertical distances between the nozzle and the fuel surface (0.75–2 m). Extinction performance of the nozzle in the present work is compared with the other performances of different water mist systems reported in the literature.

Proceeding of: Fifteenth International Conference on Fluidization, Fluidization XV, Fluidization for Emerging Green Technologies, Montebello, Canada, May 22nd to 27th, 2016 The present work experimentally assesses the effect of vibration on the dynamics of particles in a fluidized bed of triangular shape. The base of the bed is composed of two inclined walls, each one forming an angle of 45 with the horizontal. The bed has 0.206 m span and 0.01 m thickness. The bed vessel is made of antistatic PMMA in order to allow optical access with a high-speed camera. The bed is mounted on an electrodynamic shaker which produces vertical vibration. The bed material is ballotini particles with a mean diameter of 1.15 mm up to the top of the inclined walls. Air was injected through the inclined bed walls to fluidize the bed to explore whether vibration of the bed vessel together with gas injection can make the dynamics of this bed different to that found when no gas is injected. A high speed camera was used to record the motion of particles in the bed. The velocity of the particles in the bed was obtained via Particle Image Velocimetry (PIV). The results show that several circulation patterns are observed as a function of vibration amplitude and frequency when the fluidization velocity is just below and above the minimum fluidization velocity. Noticeably, for zero gas velocity, particles ascend close to the side walls and descend in the center of the bed. By injecting fluidization gas, the circulation pattern of the bed can be reversed (i.e. particles descending near the inclined walls and ascending in the center of the bed). Conditions for which this reversal of the gulf stream circulation of particles appears in the triangular bed are explored in this work and these include gas superficial velocities higher than the minimum fluidization velocity and sufficiently high values of the vibration strength. This work has been partially funded by the Universidad Carlos IIIde Madrid (Ayudas a la movilidad 2015) and by the Spanish Ministry of Economy and Competitiveness (project ENE2015/00188/001).

The effect of the bed vessel vibration on the oscillatory behavior of the bed bulk and the bubbles is experimentally studied in the present work by means of Digital Image Analysis (DIA) in a pseudo-2D bed. The bed material was three different powders of Geldart A, B and AFB classifications and was operated in bubbling regime for different superficial gas velocities and vibration amplitudes and frequencies. A tracking methodology was developed in order to follow the oscillatory motion of the bed bulk and each individual bubble in the system. This allowed the analysis of the interaction of the dense phase of the bed with the oscillations of the Nibble diameter, position and velocity. The results indicate that both the center of mass of the bed and the bubble characteristics follow the oscillation of the bed vessel with a similar frequency but with a phase delay. The amplitude and phase delay of the oscillation of the center of mass of the bed are more sensitive to variations of the vibration frequency than to variations of the vibration amplitude of the bed vessel. Both the amplitude and the frequency of the bed vessel vibration have a stronger impact on the bubble behavior of beds filled with small particles. The existence of a phase delay between the oscillations of bubble characteristics in the lower and upper sections of the bed indicates the existence of compression-expansion waves in the dense phase that modify the bubble behavior along the bed despite bubbles are interacting with each other. The presence of compression-expansion waves may shed light onto the different behaviors encountered for the mean bubble behavior in vibrated fluidized beds. This work has been partially funded by the Universidad Carlos III de Madrid, Ayudas a la Movilidad 2014.

Bread crumb cellular structure and elasticity were monitored during aging and their relation to the main flour constituents, gluten and starch, was studied. The linear relation between the time-dependent slope of the linear part of the force-deformation curve, obtained in a static compressive test, and the shear modulus, obtained in quasi-static shear wave measurements, allowed calculating the Poisson's ratio of bread crumb. This ratio and, thus, cell geometry remain unaffected during bread storage. While the elastic modulus of bread crumb strongly increased upon storage, image analysis and ultrasonic inspection, interpreted in the framework of the Biot-Allard model for porous structures, further confirmed that its cellular structure parameters did not change. Changing gluten properties in dough by means of redox agents had a profound impact on bread crumb density and its foam structure without affecting the rheological properties of the crumb cell walls. In agreement with the theory for cellular solids with open cells, bread with a lower density and a uniform crumb structure initially had a lower elastic modulus, which was maintained during aging, while bread with a higher density showed the opposite. Inclusion of an antifirming maltogenic exo-amylase in the recipe altered neither bread density, nor its macroscopic cellular structure parameters, but strongly affected the impact of storage on crumb texture. It was concluded that, without affecting starch properties or moisture content, the bread density, which is inter alia related to gluten properties, is a major determinant of bread crumb structure and texture during storage. In breads with a similar density and crumb foam structure, the evolution of crumb modulus during storage is determined by the changes in starch. ispartof: Food Biophysics vol:7 issue:2 pages:173-181 status: published

CFD-DEM algorithm which couples the macroscopic governing equations for gas phase and the second law of motions for individual particles in the system, is more accurate than the continuum based description of the particle phase. However, certain key challenges still remain which are the massive computational time and the selection of appropriate drag correlation. In the present work, coupled CFD-DEM simulations of two and three dimensional fluidized beds are carried out using the open source code MFIX, first, to understand the performance of different drag laws and second to investigate the effect of scaling down the actual geometry on fluidization behavior. The average gas and solid phase properties such as bed pressure drop, and the mean particle velocity, are determined and compared with the experimental results to benchmark the numerical simulations. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Understanding hydrodynamics of bubbling fluidized beds is crucial in proper design and scale up of these beds. CFD models have shown promise in gaining this understanding. In order to generate confidence in CFD models, predicted time averaged and dynamical characteristics of the bubbling fluidized beds need to be validated against experimental data. This paper describes such studies with rectangular fluidized beds operated with a central jet. Digital image analysis and analysis of wall pressure fluctuations were used for this characterization. Fluidization of two types of particles, glass and polypropylene (PP) was studied at two different initial bed heights of H / D = 1 and 2 with three central jet velocities 5, 10 and 20 m/s. Time averaged as well as dynamical characteristics were studied. The Eulerian–Eulerian two fluid model based on kinetic theory of granular flows was used to simulate these experiments. The predicted results were compared with the experimental data and previously published correlations. Although, there is agreement with experimental data in some aspects, complete agreement was not found. The presented experimental data and comparison with CFD predictions will provide useful basis for further work on understanding bubbling fluidized beds.

This paper presents the application of the Biot-Allard model for characterization of the porous structure of bread crumb. This model describes the wave propagation in porous materials and is commonly used for the evaluation of sound absorbing properties of soft poro-elastic foams. Two different bread types, a fine grain bread (FGB) with small cells and a coarse grain bread (CGB) with larger gas cells, were analyzed using both image analysis (IA) and ultrasonic techniques. IA figures for mean cell area, cell to total area ratio and number of cells/cm(2) were 0.25 and 0.47, 0.32 and 0.41, and 112.8 and 81.6, respectively for FGB and CGB. The ultrasonic technique used non-contact air coupled transducers at ultrasonic frequencies. The phase velocity and attenuation of ultrasonic waves were measured in transmission and reflection experiments. These measurements confirmed the structural differences between the two different bread types and the usefulness of the Biot-Allard model for description of wave propagation in bread crumb for a wide frequency range. In addition, the use of non-contact ultrasound allowed estimating flow resistivity, open porosity, a measure for the size of the intersections in the crumb cell walls. and tortuosity which can be considered as a structural form factor. (c) 2006 Elsevier Ltd. All rights reserved. ispartof: Food research international vol:39 issue:10 pages:1067-1075 status: published

The development of computer-aided semen analysis (CASA) has made it possible to study sperm motility characteristics objectively and longitudinally. In this 2-year study of 8 sperm donors, we used CASA to measure 7 semen parameters (concentration, percentage of motile spermatozoa, curvilinear velocity, average path velocity, straight-line velocity, amplitude of lateral head displacement, and beat/cross frequency). The frequency distributions of the 7 parameters in the semen samples of each donor were investigated. All parameters but one were normally distributed; concentration was distributed log-normally. Variation within individual donors and between donors was studied. Analysis of variance demonstrated that variation between donors was not explained by the longitudinal variation within individual donors. Variations in motility characteristics between donors were substantial, which may make motility characteristics of limited value as a tool for establishing fertility. Strong correlations were found between the 7 parameters, partly because by definition, motility characteristics are interdependent. Fisher's discriminant analysis demonstrated that each donor appeared to have his own set of semen characteristics and, more specifically, his own motility signature. From this data set it can be predicted that in order to find population means among sperm, it may be more efficient to measure more subjects than to increase the number of samples per subject.

Objectives: To determine the impact on synovial histopathology of changes in clinical disease activity in the absence of effective treatment.Methods: Twelve patients with active RA not receiving effective treatment were studied over a 14 week period. Synovial biopsy specimens obtained at baseline and week 14 were analysed by histology and immunohistochemistry.Results: Over the course of 14 weeks, there was a trend towards a decrease of the DAS28, with 7/12 patients being good or moderate DAS28 responders despite the absence of effective treatment. Patients' assessment of global disease activity and swollen joint count both decreased significantly. Histologically, there was a decrease of lining layer hyperplasia and lymphoid aggregates, a similar trend for vascularity, but there was no effect on global synovial infiltration. Accordingly, there was no decrease of the cellular infiltration with T lymphocytes ( CD3, CD4, CD8), B lymphocytes ( CD20), plasma cells ( CD38), dendritic cells ( CD1a, CD83), and even an increase of CD163+ sublining macrophages, with a similar trend for CD68+ sublining macrophages. The changes in DAS28 scores in these patients did not correlate with changes in histological variables, with the exception of an inverse correlation with plasma cells. Remarkably, even in the DAS28 responders, no significant changes in synovial inflammatory infiltration were noted.Conclusions: Despite variations in global disease activity, synovial inflammatory infiltration did not change significantly in the absence of effective treatment. The lack of a placebo effect on synovial markers of treatment response such as sublining macrophages can facilitate conclusive early phase trials with small numbers of patients with RA.

The development of computer-aided semen analysis (CASA) has made it possible to study sperm motility characteristics objectively and longitudinally. In this 2-year study of 8 sperm donors, we used CASA to measure 7 semen parameters (concentration, percentage of motile spermatozoa, curvilinear velocity, average path velocity, straight-line velocity, amplitude of lateral head displacement, and beat/cross frequency). The frequency distributions of the 7 parameters in the semen samples of each donor were investigated. All parameters but one were normally distributed; concentration was distributed log-normally. Variation within individual donors and between donors was studied. Analysis of variance demonstrated that variation between donors was not explained by the longitudinal variation within individual donors. Variations in motility characteristics between donors were substantial, which may make motility characteristics of limited value as a tool for establishing fertility. Strong correlations were found between the 7 parameters, partly because by definition, motility characteristics are interdependent. Fisher's discriminant analysis demonstrated that each donor appeared to have his own set of semen characteristics and, more specifically, his own motility signature. From this data set it can be predicted that in order to find population means among sperm, it may be more efficient to measure more subjects than to increase the number of samples per subject.

Background Pseudomonas syringae can cause stem necrosis and canker in a wide range of woody species including cherry, plum, peach, horse chestnut and ash. The detection and quantification of lesion progression over time in woody tissues is a key trait for breeders to select upon for resistance. Results In this study a general, rapid and reliable approach to lesion quantification using image recognition and an artificial neural network model was developed. This was applied to screen both the virulence of a range of P. syringae pathovars and the resistance of a set of cherry and plum accessions to bacterial canker. The method developed was more objective than scoring by eye and allowed the detection of putatively resistant plant material for further study. Conclusions Automated image analysis will facilitate rapid screening of material for resistance to bacterial and other phytopathogens, allowing more efficient selection and quantification of resistance responses. Electronic supplementary material The online version of this article (doi:10.1186/s13007-015-0100-8) contains supplementary material, which is available to authorized users.