364 research outputs found
Concentrate supplementation on milk yield, methane and CO2 production in crossbred dairy cows grazing in tropical climate regions
The objective of this study was to evaluate the level of concentrate supplementation on the production and chemical composition of milk from 12 crossbred F1 dual-purpose cows ( Bos taurus – Bos indicus) and estimate the emission of CH4, N2O, and CO2 gases. The study included 12 crossbred F1 dual-purpose cows over 60 days of lactation. The cows grazed on 28% tropical native grassland and 72% Brachiaria spp. and Cynodon neumfluensis, supplemented with 0, 150, 300, and 450g of concentrate per kg daily milk production, during three experimental periods of 15 days each in a crossover design. Pasture and concentrate samples were collected and were analyzed for dry matter, crude protein, neutral detergent fiber, and acid detergent fiber. Milk production (kg d-1) was recorded daily, nitrous oxide (N2O), and emissions from excreta and daily CH4 production were calculated. Results were analyzed with the SAS MIXED procedure. Concentrate supplementation in tropical crossbred dairy cows did not improve milk yield but increased CH4 and N2O production (P < 0.0001) per cow as the concentrate increased in the diet; the Ym factor from the tropical region yielded less CH4 than the IPCC Ym model (P < 0.0001). In conclusion, the calculation of CH4 using specific emission factors for the tropical climate region is better than the IPCC default emission factors in order not to overestimate the CH4 emissions
Fully Automatic Method for the Visual Acuity Estimation Using OCT Angiographies
[Abstract]
In this work we propose the automatic estimation of the visual acuity of patients with retinal vein occlusion using Optical Coherence Tomography by Angiography (OCTA) images. To do this, we first extract the most relevant biomarkers in this imaging modality—area of the foveal avascular zone and vascular densities in different regions of the OCTA image. Then, we use a support vector machine to estimate the visual acuity. We obtained a mean absolute error of 0.1713 between the manual visual acuity measurement and the estimated, being considered satisfactory results.Centro de Investigación de Galicia; ED431G 2019/01Xunta de Galicia; DTS18/00136Ministerio de Ciencia, Innovación y Universidades; RTI2018-095894-B-I0
Automatic extraction of vascularity measurements using OCT-A images
The conference was held in Belgrade, Serbia, 3-5 September 2018.[Absctract]: Optical Coherence Tomography Angiography (OCT-A) represents a new modality of ophthalmological imaging that stands out for being a non-invasive capture technique that facilitates the analysis of the vascular characteristics of the eye fundus. In this paper, we propose a complete automatic methodology that identifies the vascular and avascular zones in OCT-A images, quantifying each one of them for their posterior use in clinical analyses and diagnostic processes. To achieve this, we firstly intensify the vascular characteristics to facilitate the posterior extraction. Then, a set of image processing techniques are combined to differentiate both vascular and avascular regions and, finally, measure their representative parameters. The proposed methodology was tested on a set of images that were marked by an expert ophthalmologist, being used as reference in the validation of the method. The proposed approach presented satisfactory results in the validation experiments with the vascular and avascular measurements, demonstrating their utility for the diagnosis and monitoring of different vascular diseases that are frequently analysed through the retinal microcirculation.This work is supported by the Instituto de Salud Carlos III, Government of Spain and FEDER funds of the European Union through the PI14/02161 and the DTS15/00153 research projects and by the Ministerio de Economía y
Competitividad, Government of Spain through the DPI2015-69948-R research project. Also, this work has received
financial support from the European Union (European Regional Development Fund - ERDF) and the Xunta de Galicia, Centro singular de investigación de Galicia accreditation 2016-2019, Ref. ED431G/01; and Grupos de Referencia
Competitiva, Ref. ED431C 2016-047.Xunta de Galicia; ED431G/01Xunta de Galicia; ED431C 2016-04
Robust segmentation of retinal layers in optical coherence tomography images based on a multistage active contour model
[Abstract]: Optical Coherence Tomography (OCT) constitutes an imaging technique that is increasing its popularity in the ophthalmology field, since it offers a more complete set of information about the main retinal structures. Hence, it offers detailed information about the eye fundus morphology, allowing the identification of many intraretinal pathological signs. For that reason, over the recent years, Computer-Aided Diagnosis (CAD) systems have spread to work with this image modality and analyze its information. A crucial step for the analysis of the retinal tissues implies the identification and delimitation of the different retinal layers. In this context, we present in this work a fully automatic method for the identification of the main retinal layers that delimits the retinal region. Thus, an active contour-based model was completely adapted and optimized to segment these main retinal boundaries. This fully automatic method uses the information of the horizontal placement of these retinal layers and their relative location over the analyzed images to restrict the search space, considering the presence of shadows that are normally generated by pathological or non-pathological artifacts. The validation process was done using the groundtruth of an expert ophthalmologist analyzing healthy as well as unhealthy patients with different degrees of diabetic retinopathy (without macular edema, with macular edema and with lesions in the photoreceptor layers). Quantitative results are in line with the state of the art of this domain, providing accurate segmentations of the retinal layers even when significative pathological alterations are present in the eye fundus. Therefore, the proposed method is robust enough to be used in complex environments, making it feasible for the ophthalmologists in their routine clinical practice.This work was supported by the Instituto de Salud Carlos III, Government of Spain and FEDER funds of the European Union (PI14/02161 and DTS15/00153), the Ministerio de Economía y Competitividad, Government of Spain (DPI2015-69948-R), the Xunta de Galicia, Centro singular de investigacíon de Galicia accreditation 2016–2019 (ED431G/01), and Grupos de Referencia Competitiva (ED431C 2016-047).Xunta de Galicia; ED431G/01Xunta de Galicia; ED431C 2016-04
Automatic segmentation of the foveal avascular zone in ophthalmological OCT-A images
Data Availability: All images OCT-A files are available from the OCTAGON database (http://www.varpa.org/research/ophtalmology.html) All code files are available in https://github.com/macarenadiaz/FAZ_Extraction.[Abstract]: Angiography by Optical Coherence Tomography (OCT-A) is a non-invasive retinal imaging modality of recent appearance that allows the visualization of the vascular structure at predefined depths based on the detection of the blood movement through the retinal vasculature. In this way, OCT-A images constitute a suitable scenario to analyze the retinal vascular properties of regions of interest as is the case of the macular area, measuring the characteristics of the foveal vascular and avascular zones. Extracted parameters of this region can be used as prognostic factors that determine if the patient suffers from certain pathologies (such as diabetic retinopathy or retinal vein occlusion, among others), indicating the associated pathological degree. The manual extraction of these biomedical parameters is a long, tedious and subjective process, introducing a significant intra and inter-expert variability, which penalizes the utility of the measurements. In addition, the absence of tools that automatically facilitate these calculations encourages the creation of computer-aided diagnosis frameworks that ease the doctor’s work, increasing their productivity and making viable the use of this type of vascular biomarkers. In this work we propose a fully automatic system that identifies and precisely segments the region of the foveal avascular zone (FAZ) using a novel ophthalmological image modality as is OCT-A. The system combines different image processing techniques to firstly identify the region where the FAZ is contained and, secondly, proceed with the extraction of its precise contour. The system was validated using a representative set of 213 healthy and diabetic OCT-A images, providing accurate results with the best correlation with the manual measurements of two experts clinician of 0.93 as well as a Jaccard’s index of 0.82 of the best experimental case in the experiments with healthy OCT-A images. The method also provided satisfactory results in diabetic OCT-A images, with a best correlation coefficient with the manual labeling of an expert clinician of 0.93 and a Jaccard’s index of 0.83. This tool provides an accurate FAZ measurement with the desired objectivity and reproducibility, being very useful for the analysis of relevant vascular diseases through the study of the retinal micro-circulation. © 2019 Díaz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This work is supported by the Ministerio de Economía y Competitividad, Government of Spain through the DPI2015-69948-R research project. Also, this work has received financial support from the European Union (European Regional Development Fund - ERDF) and the Xunta de Galicia, Centro singular de investigación de Galicia accreditation 2016-2019, Ref. ED431G/01; Grupos de Referencia Competitiva, Ref. ED431C 2016-047 and Instituto de salud Carlos III, Ref. PI-00940. Also, this work has received partial financial support from the Fundación Mutua Madrileña project, Ref. 2017/365.Xunta de Galicia; ED431G/01Xunta de Galicia; ED431C 2016-047Fundación Mutua Madrileña; 2017/36
The Lituya Bay landslide-generated mega-tsunami – numerical simulation and sensitivity analysis
The 1958 Lituya Bay landslide-generated mega- tsunami is simulated using the Landslide-HySEA model, a recently developed finite-volume Savage–Hutter shallow wa- ter coupled numerical model. Two factors are crucial if the main objective of the numerical simulation is to reproduce the maximal run-up with an accurate simulation of the in- undated area and a precise recreation of the known trimline of the 1958 mega-tsunami of Lituya Bay: first, the accu- rate reconstruction of the initial slide and then the choice of a suitable coupled landslide–fluid model able to reproduce how the energy released by the landslide is transmitted to the water and then propagated. Given the numerical model, the choice of parameters appears to be a point of major im- portance, which leads us to perform a sensitivity analysis. Based on public domain topo-bathymetric data, and on in- formation extracted from the work of Miller (1960), an ap- proximation of Gilbert Inlet topo-bathymetry was set up and used for the numerical simulation of the mega-event. Once optimal model parameters were set, comparisons with ob- servational data were performed in order to validate the nu- merical results. In the present work, we demonstrate that a shallow water type of model is able to accurately reproduce such an extreme event as the Lituya Bay mega-tsunami. The resulting numerical simulation is one of the first successful attempts (if not the first) at numerically reproducing, in de- tail, the main features of this event in a realistic 3-D basin geometry, where no smoothing or other stabilizing factors in the bathymetric data are applied
Automatic Visual Acuity Estimation by Means of Computational Vascularity Biomarkers Using Oct Angiographies
[Abstract] Optical Coherence Tomography Angiography (OCTA) constitutes a new non-invasive ophthalmic image modality that allows the precise visualization of the micro-retinal vascularity that is commonly used to analyze the foveal region. Given that there are many systemic and eye diseases that affect the eye fundus and its vascularity, the analysis of that region is crucial to diagnose and estimate the vision loss. The Visual Acuity (VA) is typically measured manually, implying an exhaustive and time-consuming procedure. In this work, we propose a method that exploits the information of the OCTA images to automatically estimate the VA with an accurate error of 0.1713.Instituto de Salud Carlos III; DTS18/00136Ministerio de Economía y Competitividad; DPI2015-69948-RXunta de Galicia; ED431G/01Xunta de Galicia; ED431C 2016-047Ministerio de Ciencia, Innovación y Universidades; RTI2018-095894-B-I0
The application of diode laser in the treatment of oral soft tissues lesions. A literature review
Since its appearance in the dental area, the laser has become a treatment of choice in the removal of lesions in the oral soft tissues, due to the numerous advantages they offer, being one of the most used currently the diode laser. The aim of this review was to determine the efficacy and predictability of diode laser as a treatment of soft tissue injuries compared to other surgical methods. A literature review of articles published in PubMed/MEDLINE, Scopus and the Cochrane Library databases between 2007 and 2017 was performed. ?Diode laser?, ?soft tissue?, ?oral cavity? and ?oral surgery? were employed for the search strategy. Only articles published English or Spanish were selected. The diode laser is a minimally invasive technology that offers great advantages, superior to those of the conventional scalpel, such as reduction of bleeding, inflammation and the lower probability of scars. Its effectiveness is comparable to that of other types of lasers, in addition to being an option of lower cost and greater ease of use. Its application in the soft tissues has been evaluated, being a safe and effective method for the excision of lesions like fibromas, epulis fissuratum and the accomplishment of frenectomies. The diode laser can be used with very good results for the removal of lesions in soft tissues, being used in small exophytic lesions due to their easy application, adequate coagulation, no need to suture and the slightest inflammation and pain
Ensilado de maíz, una revisión sistemática de la calidad y el rendimiento en diferentes regiones del mundo
Corn sialge (Zea mays L.) is the most widely used in the world in dairy cattle diets because of its higher biomass yields, palatability, homogeneous quality at harvest, and ease of silage due to its higher soluble sugar content. Studies were systematically searched to know the silage corn quality and yield from different countries concerning dry matter yield (t/ha), population density (plant density/ha), quantity of Dry Matter (DM), Crude Protein (CP), Neutral Detergent Fiber (NDF), Non-Fibrous Carbohydrates (NFC), Organic Matter (OM), DM Digestibility (DMD), Neutral Detergent Fiber Digestibility (NDFD), and milk production (kg) per hectare (kg milk/ha) using MILK2006®. Six clusters (CL, PROC CLUSTER) of corn silage were analyzed: CL1: “Starch,” which included DMD, DNDF, TDN1 x DM, Mega calories per kg of DM, and kg of milk/t DM; CL2: “ether extract” which included TDN1 x DM, Mcal/kg DM, and kg of milk/t DM; CL3: “DM,” composed only of DNDF; CL4: “Plant Density,” including Yield of DM/ha and Milk Production/ha; CL5: “NDF,” and CL6: “CP.” In conclusion, CL1 is characterized by a higher DMD, NDFD, CNF, and starch, which allow higher TDN1 x DM and an energy concentration (Mcal/kg DM) with higher milk production (kg milk/ha). CL2 with a higher ether extract (EE) allows higher TDN1 x DM and an energy concentration (Mcal/kg DM) having a higher milk production (kg milk/ha). The DM concentration increases in the whole plant because of maturity, affecting the starch content and NDFD; the DM content (> 35 g/100 g DM) mainly causes a decrease in the NDFD, while in a very early stage of DM harvest (< 25 g/100 g DM) a low ratio of starch:NDFD is present.El ensilado de maíz (Zea mays L.) es el más utilizado en el mundo en dietas de ganado lechero por sus mayores rendimientos de biomasa, palatabilidad, calidad homogénea a la cosecha y facilidad de ensilar por su mayor contenido de azúcar soluble. Se realizó una búsqueda sistemática de estudios para conocer la calidad y el rendimiento de ensilados de maíz en diferentes países con relación al rendimiento de materia seca (t/ha), densidad de población (densidad de plantas/ha), Materia Seca (MS), Proteína Cruda (PC), Fibra Detergente Neutra (FDN), Carbohidratos No Fibrosos (CNF), Materia Orgánica (MO), Digestibilidad de la MS (DMS), Digestibilidad de Fibra Detergente Neutra (DFDN) y producción de leche por hectárea (kg de leche/ha), mediante el programa MILK2006®. Se analizaron 6 clúster (CL, PROC CLUSTER) de ensilado de maíz: CL1: “Almidón”, que incluyó DMS, DFDN, TDN x MS, Mega calorías por kg de MS y kg de leche/tonelada/MS; CL2: “extracto de éter” que incluyó TDN1 x MS, Mcal/kg MS y kg de leche/tonelada MS; CL3: “MS”, conformado solo por DFDN; CL4: “Densidad de plantas” incluyendo el Rendimiento de MS/ha y Producción de leche/ha, CL5: “FDN” y CL6: “PC”. El CL1 se caracterizó por una mayor DMS, DFND, CNF y almidón que permiten una mayor TDN1 x MS y una concentración de energía (Mcal/kg MS) que muestra una mayor producción de leche (kg de leche/tonelada MS/ha). Las características de CL2 con mayor extracto de éter (EE), permiten un mayor TDN1 x MS y concentración de energía (Mcal/kg MS) con mayor producción de leche (kg de leche/tonelada MS/ha) en comparación con otros clústeres. La concentración de MS aumenta en toda la planta por efecto de la madurez, lo que afecta el contenido de almidón y DFDN; el contenido de MS (> 35 g/100 g MS) provoca principalmente una disminución de la DFDN, mientras que en una etapa muy temprana de cosecha de MS (< 25 g/100 g MS) se presenta una baja relación almidón-DFDN
Effect of different growth stages of rapeseed (brassica rapa L.) on nutrient intake and digestibility, nitrogen balance, and rumen fermentation kinetics in sheep diets
The objective of the present study was to determine the dietary effect of different growth stages of rapeseed (Brassica rapa L.) on nutrient intake and digestibility, nitrogen balance, and rumen fermentation kinetics in sheep.The objective of the present study was to determine the dietary effect of different growth stages of rapeseed (Brassica rapa L.) on nutrient intake and digestibility, nitrogen balance, and rumen fermentation kinetics in sheep. Four dietary treatments were utilised. A basal control diet based on alfalfa hay, oat hay, soybean meal and corn grain. Then alfalfa hay was replaced with 300 g/kg DM of rapeseed forage harvested at three different growth stages: Vegetative, Flowering and Pod. In vitro gas production was determined using three rumen cannulated Suffolk sheep in a completely randomised design, and nutrients intake and digestibility of each diet were determined using four Suffolk sheep in a 4 4 Latin square design with 21 d periods consisting of 14 d for diet adaptation and 7 d for sample collection. Feed intake and excretion of faeces and urine were recorded. Dry matter intake was higher for control and Pod compared to Vegetative and Flowering. The digestibility of dry matter, organic matter, neutral detergent fibre and acid detergent fibre were similar among treatments. Nitrogen intake was higher for control and Pod and lower for Vegetative and Flowering. In vitro gas production was similar among treatments (P > .05). In vitro gas yield at 24 h was higher (P < .05) for control than the rest of the treatments. Overall, inclusion of 300 g/kg DM of rapeseed forage harvested at pod stage as a substitute for alfalfa hay is an alternative source of protein without affecting nutrient intake and digestibility.Amelia Zetina Sanchez thanked the National Council for Science and Technology (Conacyt, Mexico) for the scholarship for her studies at the Universidad Nacional Autonoma de Mexico. Lizbeth Esmeralda Robles Jimenez was awarded a Conacyt-Mexico scholarship during her PhD program at the Agricultural Sciences and Natural Resources at the Universidad Autonoma del Estado de México. During the study, Dr. Einar Vargas-Bello-Pérez was a visiting scholar also supported by project number 4974/2020CIB from Universidad Autonoma del Estado de México
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