Shape analysis and tracking of migrating macrophages

Cell migration is important in many human processes of development and disease. In Cancer, migration can be related to metastasis or cell defects. A precise analysis of the cell shapes in biological studies could lead to insights about migration. Therefore, this paper describes an algorithm to iteratively segment, track and analyse the shape of macrophages from fluorescent microscopy image sequences. This process allows observation of shape variations as the cells migrate. The algorithm identifies and separates overlapping and non-overlapping cells, then for the non-overlapping cases analyses the shape and extracts a series of measurements, including the number of "corner" or pointy edges through a multiscale angle variation matrix, anglegram. The shape evolution algorithm was tested on fluorescently labelled macrophages observed on embryos of Drosophila melanogaster

Analysis of the Interactions of Migrating Macrophages

Understanding the migrating patterns of cells in the immune system is of great importance; especially the changes of direction and its cause. For macrophages and other immune cells, excessive migration could be related to autoimmune diseases and cancer. In this work, an algorithm to analyse the change in direction of cells before and after they interact with another cell is proposed. The main objective is to provide insights into the notion that interactions between cell structures appear to anticipate migration. Such interactions are determined when the cells overlap and form clumps of two or more cells. The algorithm integrates a segmentation technique capable of detecting overlapping cells and a tracking framework into a tool for the analysis of the trajectories of cells before and after they overlap. The preliminary results show promise into the analysis and the hypothesis proposed, and it lays the ground work for further developments

The Effects of Grazing Cover Crops on Animal Performance and Soybean Production

Grazing cover crops has the potential to offset costs incurred with cover crop establishment, thus incentivizing management adoption. Information regarding cover crop species in combination with grazing and their subsequent effects on soybean production is limited. A field trial was conducted in Newton, MS from 2019 to 2021 to assess these effects. Cover crop treatments included oats (O), O + crimson clover (OC), and OC + radish (OCR) were applied in a randomized complete block design with three replications. Cover crops differed in nutritive analysis; O had significantly lower mean CP, but greater total daily nutrients (TDN). Weaned beef steers grazing cover crops had lower ADG in the OCR treatment (3.03 lb hd-1 d-1), compared to O (3.52 lb hd-1 d-1) and OC (3.55 lb hd-1 d-1). No significant difference was observed in soybean grain yield between cover crop treatments. Mean yields were 51.1, 46.1, and 38.7 bu ac-1 for the O, OC, and OCR treatments, respectively. Total net returns for grazing plus soybean production were significantly lower in the OCR ($817.51 ac-1), compared to the O ($1,107.03 ac-1) and OC ($1,071.15 ac-1) treatments. These returns suggest that grazing provides an added value to cover crop establishment and provides incentives for increased revenue for producers willing to combine livestock and row crop enterprises

Segmentation of Overlapping Macrophages Using Anglegram Analysis

This paper describes the automatic segmentation of overlapping cells through different algorithms. As the first step, the algorithm detects junctions between the boundaries of overlapping objects based on the angles between points of the overlapping boundary. For this purpose, a novel 2D matrix with multiscale angle variation is introduced, i.e anglegram. The anglegram is used to find junctions of overlapping cells. The algorithm to retrieve junctions from the boundary was tested and validated with synthetic data and fluorescently labelled macrophages observed on embryos of Drosophila melanogaster. Then, four different segmentation techniques were evaluated: (i) a Voronoi partition based on the nuclei positions, (ii) a slicing method, which joined the clumps together (junction slicing), (iii) a partition based on the following of the edges from the junctions (edge following), and (iv) a custom self-organising map to fit to the area of overlap between the cells. Only (ii)-(iv) were based on the junctions. The segmentation results were compared based on precision, recall and Jaccard similarity. The algorithm that reported the best segmentation was the junction slicing

El derecho laboral marítimo introducido por el Decreto Ley núm. 8 de 1998.

Las tendencias de las relaciones internacionales en el ámbito de la protección de los océanos tomó un curso drástico hacia la seguridad de la navegación marítima. A partir de este hecho de trascendencia internacional el estudio de este proyecto de investigación es de tipo correlacional y no experimental descriptivo y se centró en la evolución de las instituciones del Derecho Laboral Marítimo en sus dos (2) vertientes a saber: la vertiente de la formación, titulación y guardia y la vertiente de los derechos y obligaciones de los marinos y de los armadores en el desarrollo de la relación laboral; estos componentes en su conjunto conforman dos de las competencias del Sector Marítimo, sobre la base del principio de navegabilidad marítima. Con una muestra de 20 abogados, resultado de la aplicación de esta metodología demostró que el Decreto Ley N° 8 del 26 de febrero de 1998, requiere de profundas reformas en la vertiente de los derechos y obligaciones de los marinos y de los armadores en el desarrollo de las relaciones de trabajo, a efectos de que recoja en su estructura capitular las instituciones contenidas en el Convenio sobre el Trabajo Marítimo, 2006 y desde el enfoque operativo, ya es impostergable la constitución de tos juzgados laborales marítimos creados por el comentado Decreto y que todavía no han sido implementados

Do software models based on the UML aid in source-code comprehensibility? Aggregating evidence from 12 controlled experiments

In this paper, we present the results of long-term research conducted in order to study the contribution made by software models based on the Unified Modeling Language (UML) to the comprehensibility of Java source-code deprived of comments. We have conducted 12 controlled experiments in different experimental contexts and on different sites with participants with different levels of expertise (i.e., Bachelor’s, Master’s, and PhD students and software practitioners from Italy and Spain). A total of 333 observations were obtained from these experiments. The UML models in our experiments were those produced in the analysis and design phases. The models produced in the analysis phase were created with the objective of abstracting the environment in which the software will work (i.e., the problem domain), while those produced in the design phase were created with the goal of abstracting implementation aspects of the software (i.e., the solution/application domain). Source-code comprehensibility was assessed with regard to correctness of understanding, time taken to accomplish the comprehension tasks, and efficiency as regards accomplishing those tasks. In order to study the global effect of UML models on source-code comprehensibility, we aggregated results from the individual experiments using a meta-analysis. We made every effort to account for the heterogeneity of our experiments when aggregating the results obtained from them. The overall results suggest that the use of UML models affects the comprehensibility of source-code, when it is deprived of comments. Indeed, models produced in the analysis phase might reduce source-code comprehensibility, while increasing the time taken to complete comprehension tasks. That is, browsing source code and this kind of models together negatively impacts on the time taken to complete comprehension tasks without having a positive effect on the comprehensibility of source code. One plausible justification for this is that the UML models produced in the analysis phase focus on the problem domain. That is, models produced in the analysis phase say nothing about source code and there should be no expectation that they would, in any way, be beneficial to comprehensibility. On the other hand, UML models produced in the design phase improve source-code comprehensibility. One possible justification for this result is that models produced in the design phase are more focused on implementation details. Therefore, although the participants had more material to read and browse, this additional effort was paid back in the form of an improved comprehension of source code

Capital allocation for credit portfolios with kernel estimators

Determining contributions by sub-portfolios or single exposures to portfolio-wide economic capital for credit risk is an important risk measurement task. Often economic capital is measured as Value-at-Risk (VaR) of the portfolio loss distribution. For many of the credit portfolio risk models used in practice, the VaR contributions then have to be estimated from Monte Carlo samples. In the context of a partly continuous loss distribution (i.e. continuous except for a positive point mass on zero), we investigate how to combine kernel estimation methods with importance sampling to achieve more efficient (i.e. less volatile) estimation of VaR contributions.Comment: 22 pages, 12 tables, 1 figure, some amendment

An opinion on the regulation of bone marrow adipose tissue by dietary fatty acids

7 PáginasObesity has a significant impact on predisposition to various diseases and also affects the viability and choice of haematopoietic stem cells (HSCs) to favour myeloid cell production and/or turnover, all of which are extremely important for the functioning of immune system. As the production of blood cells and mobilization of HSCs and their progeny are regulated, at least in part, by multifaceted interactions through signals that come from the bone marrow (BM) microenvironment, it does not seem astonishing to assume that circumstances that cause alterations in BM structure will unavoidably cause alterations in mesenchymal cells such as adipocytes and lineages from HSCs. The existence of adipose tissue in BM or marrow fat (BMAT) is well known, although its origin, expansion, and functions are poorly understood. Inspired by other studies showing the potential role for olive oil and omega-3 long chain polyunsaturated fatty acids (omega-3 PUFAs) on BM health, and by our own preliminary findings showing the effects of monounsaturated (olive oil) but not saturated (milk cream) dietary fats to contain neutrophils and CD14high monocytes in BM during postprandial periods in healthy volunteers, herein we asked whether dietary fats (saturated fatty acids, SFAs, monounsaturated fatty acids, MUFAs, and omega-3 PUFAs) may be a candidate lifestyle factor to modulate the expansion, composition, and function of BMAT, the infiltration of adipose tissue macrophages (ATMs) in BMAT and the mobilization of HSCs and mature myeloid cells from BM during high-fat-induced obesity in mice. This is the first time that the interplay between different dietary fatty acids, obesity, and BM is addressed.Una opinión sobre la regulación del tejido adiposo de médula ósea por los ácidos grasos de la dieta. La obesidad aumenta de forma significativa la susceptibilidad a diversas enfermedades y también afecta a la viabilidad y elección del destino de las células madre hematopoyéticas (HSCs) y las cinéticas de producción de los leucocitos que provienen de ellas, todo ello de extrema importancia para el funcionamiento del sistema inmune. Considerando que la producción de células sanguíneas y movilización de HSCs y su progenie están reguladas, al menos en parte, por interacciones complejas a través de señales que provienen del microambiente de la médula ósea (BM), no parece sorprendente suponer que condiciones que causen alteraciones en la estructura de BM inevitablemente causarán alteraciones en las células mesenquimales como los adipocitos y los linajes procedentes de las HSCs. Es bien conocida la existencia de tejido adiposo en BM (BMAT), aunque su origen, desarrollo, y sus funciones son muy poco conocidas. Basándonos en los resultados de otros autores, quienes han descrito que el aceite de oliva y los ácidos grasos poliinsaturados omega-3 de cadena larga (omega-3 PUFAs) pueden tener efectos beneficiosos en la salud ósea, y no en menor medida en nuestros estudios previos que sugieren la capacidad del aceite de oliva, al contrario que las grasas saturadas, de inducir la retención de neutrófilos y monocitos con CD14 en BM de voluntarios sanos durante periodos postprandiales, en esta propuesta se pretende evaluar si las grasas de la dieta (ácidos grasos saturados, SFAs, ácidos grasos monoinsaturados, MUFAs, y omega-3 PUFAs) tienen relevancia en la expansión, composición, y funcionalidad de BMAT, en la infiltración de macrófagos de tejido adiposo (ATMs) en BMAT, y en la movilización de HSCs y células maduras mieloides de BM durante la obesidad inducida por dietas ricas en grasas en animales de experimentación. Es la primera vez que se aborda la posible interacción entre diferentes ácidos grasos de la dieta, la obesidad, y BM.This work was supported by the grant AGL2016-80852-R from The Spanish Ministry of Science, Innovation and Universities. MAR acknowledges financial support from the Spanish Research Council (CSIC)/Juan de la Cierva [FJCI-2017-33132]