Automated grading of left ventricular segmental wall motion by an artificial neural network using color kinesis images

The present study describes an auxiliary tool in the diagnosis of left ventricular (LV) segmental wall motion (WM) abnormalities based on color-coded echocardiographic WM images. An artificial neural network (ANN) was developed and validated for grading LV segmental WM using data from color kinesis (CK) images, a technique developed to display the timing and magnitude of global and regional WM in real time. We evaluated 21 normal subjects and 20 patients with LVWM abnormalities revealed by two-dimensional echocardiography. CK images were obtained in two sets of viewing planes. A method was developed to analyze CK images, providing quantitation of fractional area change in each of the 16 LV segments. Two experienced observers analyzed LVWM from two-dimensional images and scored them as: 1) normal, 2) mild hypokinesia, 3) moderate hypokinesia, 4) severe hypokinesia, 5) akinesia, and 6) dyskinesia. Based on expert analysis of 10 normal subjects and 10 patients, we trained a multilayer perceptron ANN using a back-propagation algorithm to provide automated grading of LVWM, and this ANN was then tested in the remaining subjects. Excellent concordance between expert and ANN analysis was shown by ROC curve analysis, with measured area under the curve of 0.975. An excellent correlation was also obtained for global LV segmental WM index by expert and ANN analysis (R² = 0.99). In conclusion, ANN showed high accuracy for automated semi-quantitative grading of WM based on CK images. This technique can be an important aid, improving diagnostic accuracy and reducing inter-observer variability in scoring segmental LVWM.

Minor segmental wall motion abnormalities detected in patients with Chagas' disease have adverse prognostic implications

Recent data from our laboratory have shown that patients with the indeterminate form of Chagas' disease can have impairment of left ventricular contractility, as evaluated by the slope of the left ventricle end-systolic pressure-dimension relationship. We also showed that Chagas' disease patients with minimal baseline wall motion abnormalities detected by two-dimensional echocardiography have more intense contractility impairment when compared to patients with the indeterminate form of the disease without this abnormality. The prognostic implications of these findings have not been established. We evaluated 59 patients (37-76 years, mean = 55 years) with different clinical forms of Chagas' disease, who had normal left ventricular global systolic function at baseline (57.6 ± 6.9%) and who had at least one additional echo during clinical follow-up (0.4-17.6; mean 4.6 years). Group 1 consisted of 14 patients with minor baseline left ventricle wall motion abnormalities and group 2 consisted of 45 patients without these abnormalities. During follow-up, global left ventricle systolic function deterioration was observed in 10 group 1 patients (71.4%) and in only 10 group 2 patients (22.2%; P < 0.005). Age and duration of follow-up were not independent determinants of left ventricular function deterioration in these patients. The present data indicate that mild segmental left ventricular wall motion abnormalities are associated with worsening of systolic function in Chagas' disease patients who have normal baseline global systolic performance.

The effect of a segmental, localized lower limb cooling protocol on muscular strength and balance

The human neuromuscular system is susceptible to changes within the thermal environment. Cold extrinsic temperatures can significantly reduce muscle and nervous system function and communication, which can have consequences for motor performance. A repeated measures design protocol exposed participants to a 12°C cold water immersion (CWI) up to the ankle, knee, and hip to determine the effect that reduced skin and muscle temperature had on balance and strength task execution. Although a linear reduction in the ability to perform balance tasks was seen from the control condition through to the hip CWI, results from the study indicated a significant reduction in dynamic balance (Star Excursion Balance Test reach distance) performance from only the hip CWI (P<0.05). This reduced performance could have been due to an increase in joint stiffness, increased agonist-antagonist co-contraction, and/or reduced isokinetic muscular strength. Reduced physical performance due to cold temperature could negatively impact outdoor recreational athletics.

Especificidad de la relación entre la conciencia segmental y el aprendizaje de la lecto-escritura en la dislexia.

Buscar cuál es la importancia del aprendizaje lecto-escritor en la relación establecida por los niños entre el lenguaje escrito y el oral a nivel fonológico, como base de la hipótesis: los problemas lecto-escritores de los niños disléxicos provocados por la falta de desarrollo de la conciencia segmental. Estudiar que muestran una clara oposición a una instrucción que mejore su aprendizaje. Población: tres colegios públicos de Salamanca. Niveles segundo y tercero de EGB. 8 Niños, 4 varones de CI medio-bajo (DX) y 4 disléxicos de CI normal (RT). Estudio teórico sobre el aprendizaje de la lecto-escritura. Destaca la importancia del procesamiento fonológico y la conciencia segmental. Establece un relación bidireccional entre la conciencia segmental y el aprendizaje de la lecto-escritura. Deja teóricamente demostrado que el entrenamiento en tareas que desarrollan la conciencia segmental favorece el aprendizaje de la lectura, siendo de importancia para los niños disléxicos cuya dificultad se debe a la falta de este desarrollo. Hace una detallada fundamentación teórica: Bradley y Brayant (1978) sobre la dislexia proponiendo el modelo de adquisición de la lectura de Uta Frith como soporte teórico de su hipótesis. Utiliza el programa 'Escribir una palabra' (Sánchez, Rueda y Orrantía 1989) como entrenamiento de la conciencia segmental. Programa basado en el concepto de resistencia a la instrucción ligado al concepto de interacción de Vygotski (1979). Selección: WISC. Tale (análisis de la lectura y la escritura). Cuestionario para medir el nivel de metalenguaje (Rueda y Sánchez,1988). Intervención: programa de instrucción, hoja de ayudas y lista de palabras o pseudopalabras. Diseño experimental. ANOVA de un factor. Análisis particular de cada uno de los ocho casos. 'Escribir una palabra'. Los niños DX necesitaron mayor número de ayudas específicas a la conciencia segmental cuando tenían que realizar aquellos pasos del programa que suponen segmentación de los fonos. No aparecen diferencias importantes en cuanto a ayudas necesarias en las categorías de colaboración y uso del código. Los niños del grupo RT no necesitan mayor número de ayudas no específicas que los disléxicos. El problema de los niños disléxicos es que no son capaces de segmentar cuando se les instruye para hacerlo, presentan resistencia a la instrucción por ello, debe insistirse en el desarrollo de la conciencia segmental, pues es la pieza clave para el aprendizaje lectoescritor, de extrema importancia pues es lo que permite acceder al niño al conocimiento.

Conocimiento segmental y dislexia : efectos de la instrucción en la adquisición y mantenimiento del conocimiento fonémico en niños disléxicos.

Conocer los componentes de la instrucción que repercuten en la mejora de las dificultades que presentan los niños disléxicos. Estudiar la evaluación a lo largo del tiempo de los sujetos disléxicos. Específicamente, conocer si los sujetos instruidos en un programa de habilidades de segmentación obtienen conocimiento fonémico y son capaces de mantener ese conocimiento a lo largo del tiempo. Se presentan cuatro estudios. En el primer estudio participan 28 sujetos, categorizados como disléxicos, y con edades comprendidas entre los 7 y los 11 años. Los niños pertenecen a cuatro colegios de la ciudad de Salamanca. En el segundo estudio participan 25 sujetos, categorizados como disléxicos y con edades comprendidas entre los 8 y los 12 años. En el tercer estudio participan 21 sujetos disléxicos, con edades comprendidas entre los 8 y 11 años. En el cuarto estudio participan 18 sujetos, categorizados como disléxicos, con edades comprendidas entre los 7 y 10 años. En los estudios primero, segundo y tercero se utiliza un diseño experimental antes después siendo la variable independiente el tipo de tratamiento de instrucción en la lectura: programa de adición de fonos, programa de escribir una palabra, programa de instrucción en lectura y grupo control (sin tratamiento). Las variables dependientes son el conocimiento fonémico y el aprendizaje de la lectura y escritura. El cuarto estudio es de carácter longitudinal y experimental, siendo la variable independiente la instrucción (recibida o ausente) en tareas de lectoescritura; y las variables dependientes son: el conocimiento fonémico y el aprendizaje de la lectura y escritura. Los instrumentos utilizados se clasifican en dos categorías: los empleados para la selección de la muestra de niños disléxicos (entrevista, test WISC y test de análisis de lectoescritura, TALE) y las pruebas aplicadas para medir la influencia del tratamiento en las variables dependientes: test de análisis de lectoescritura (TALE) y cuestionario para medir el conocimiento fonémico. Se utilizan diversas pruebas de contraste de hipótesis: prueba de Chi cuadrado, análisis de varianza y covarianza, prueba t de Student, análisis de correlación de Pearson y análisis de conglomerados. El estudio primero concluye que el componente de segmentación es un elemento fundamental en la producción de mejoras significativas en conocimiento fonémico. Los sujetos instruidos, además de mejorar su nivel de conocimiento fonémico, también mejoran en la realización de las tareas de lectoescritura (dictado). Los resultados del segundo estudio muestran que los sujetos que participan en los programas de instrucción consiguen generalizar las habilidades de segmentación a otro tipo de tareas de segmentación más complejas y no instruidas. Los resultados del estudio tercero son reiterativos y consistentes con los estudios precedentes. El cuarto estudio muestra que el conocimiento fonémico adquirido gracias a un período de instrucción sufre un retroceso inmediato y que la edad no repercute en una mejora en este criterio. Por otro lado, los sujetos no aprovechan la instrucción de la misma forma pudiendo llegar a diferenciarse dos tipos: los que avanzan y los que presentan cierta resistencia a la instrucción. Resistencia que puede desaparecer al continuar instruyéndoles. Se comprueba la especial relevancia que para el aprendizaje de la lectura en un sistema alfabético posee el conocimiento fonológico. De los componentes utilizados en la instrucción (habilidades de segmentación, código y decodificación) se constata que es el componente de segmentación el de mayor relevancia.

Segmental dynamics in entangled linear polymer melts

We present molecular dynamics (MD) and slip-springs model simulations of the chain segmental dynamics in entangled linear polymer melts. The time-dependent behavior of the segmental orientation autocorrelation functions and mean-square segmental displacements are analyzed for both flexible and semiflexible chains, with particular attention paid to the scaling relations among these dynamic quantities. Effective combination of the two simulation methods at different coarse-graining levels allows us to explore the chain dynamics for chain lengths ranging from Z ≈ 2 to 90 entanglements. For a given chain length of Z ≈ 15, the time scales accessed span for more than 10 decades, covering all of the interesting relaxation regimes. The obtained time dependence of the monomer mean square displacements, g1(t), is in good agreement with the tube theory predictions. Results on the first- and second-order segmental orientation autocorrelation functions, C1(t) and C2(t), demonstrate a clear power law relationship of C2(t) C1(t)m with m = 3, 2, and 1 in the initial, free Rouse, and entangled (constrained Rouse) regimes, respectively. The return-to-origin hypothesis, which leads to inverse proportionality between the segmental orientation autocorrelation functions and g1(t) in the entangled regime, is convincingly verified by the simulation result of C1(t) g1(t)−1 t–1/4 in the constrained Rouse regime, where for well-entangled chains both C1(t) and g1(t) are rather insensitive to the constraint release effects. However, the second-order correlation function, C2(t), shows much stronger sensitivity to the constraint release effects and experiences a protracted crossover from the free Rouse to entangled regime. This crossover region extends for at least one decade in time longer than that of C1(t). The predicted time scaling behavior of C2(t) t–1/4 is observed in slip-springs simulations only at chain length of 90 entanglements, whereas shorter chains show higher scaling exponents. The reported simulation work can be applied to understand the observations of the NMR experiments.

Segmental chromosomal duplications harbouring group IV CONSTANS-like genes in cereals

Comparative mapping is an important component of map-based cloning in large-genome cereal species. We describe evidence of a segmental chromosomal duplication harbouring CONSTANS-like genes in barley that predates the divergence of the Oryzoideae (rice) and Pooideae (brachypodium, barley, wheat) clades, and discuss the implications of such events for comparative mapping and QTL cloning in temperate cereal crops.

Site-specific and geographical segmental social, environmental and ethical disclosures by the Ghanaian mining sector

Purpose: This paper explores the extent of site-specific and geographic segmental social, environmental and ethical reporting by mining companies operating in Ghana. We aim to: (i) establish a picture of corporate transparency relating to geographic segmentation of social, environmental and ethical reporting which is specific to operating sites and country of operation, and; (ii) gauge the impact of the introduction of integrated reporting on site-specific social, environmental and ethical reporting. Methodology/Approach: We conducted an interpretive content analysis of the annual/integrated reports of mining companies for the years 2009, 2010 and 2011 in order to extract site-specific social, environmental and ethical information relating to the companies’ mining operations in Ghana. Findings and Implications: We found that site-specific social, environmental and ethical reporting is extremely patchy and inconsistent between the companies’ reports studied. We also found that there was no information relating to certain sites, which were in operation, according to the Ghana Minerals Commission. This could simply be because operations were not in progress. Alternatively it could be that decisions are made concerning which site-specific information is reported according to a certain benchmark. One policy implication arising from this research is that IFRS should require geographic segmental reporting of material social, environmental and ethical information in order to bring IFRS into line with global developments in integrated reporting. Originality: Although there is a wealth of sustainability reporting research and an emergent literature on integrated reporting, there is currently no academic research exploring site-specific social, environmental and ethical reporting

Bradykinin receptor 1 activation exacerbates experimental focal and segmental glomerulosclerosis

Focal and segmental glomerulosclerosis (FSGS) is one of the most important causes of end-stage renal failure. The bradykinin B1 receptor has been associated with tissue inflammation and renal fibrosis. To test for a role of the bradykinin B1 receptor in podocyte injury, we pharmacologically modulated its activity at different time points in an adriamycin-induced mouse model of FSGS. Estimated albuminuria and urinary protein to creatinine ratios correlated with podocytopathy. Adriamycin injection led to loss of body weight, proteinuria, and upregulation of B1 receptor mRNA. Early treatment with a B1 antagonist reduced albuminuria and glomerulosclerosis, and inhibited the adriamycin-induced downregulation of podocin, nephrin, and alpha-actinin-4 expression. Moreover, delayed treatment with antagonist also induced podocyte protection. Conversely, a B1 agonist aggravated renal dysfunction and even further suppressed the levels of podocyte-related molecules. Thus, we propose that kinin has a crucial role in the pathogenesis of FSGS operating through bradykinin B1 receptor signaling. Kidney International (2011) 79, 1217-1227; doi:10.1038/ki.2011.14; published online 16 March 2011

Treatment of segmental tibial defects using acute bone shortening followed by gradual lengthening with circular external fixator

The aim of this study was to clinically and radiographically evaluate acute bone shortening followed by gradual lengthening in the treatment of large segmental tibia defects induced in seven clinically normal dogs. A circular external fixator was assembled with one proximal 5/8-circle ring, one middle ring and one distal ring connected with three rods. Thirty per cent of the tibia and fibula were removed in the middle and distal parts of the diaphyses, between the middle and distal rings. Acute bone shortening with compression of proximal and distal segments was performed. A subperiosteal osteotomy was performed between the half-ring and middle ring. Bone distraction started 7 days after surgery; after lengthening, the apparatus was left in place for 14 weeks for consolidation of regenerated bone. The frame was removed at the end of this period, and the dogs observed for four more weeks. Functional results were considered excellent in two, good in three and fair in the other two dogs. Bone regeneration within the distraction gap was obtained 14 weeks after neutral fixation period. We concluded that acute bone shortening followed by gradual lengthening by Ilizarov method can be used to treat extensive tibial defects in dogs, although it presents limb temporary abnormal limb shape and unequal length as early disadvantages.

Large segmental radius and ulna defect treated by bone transportation with the Ilizarov technique

An 8-year-old male Boxer with a severely contaminated open fracture of the left radius and ulna fracture, produced by a helicopter propeller, was treated using bone transport by the Ilizarov method. Extensive diaphyseal bone loss and soft-tissue vascular damage were present. The radius and ulna were stabilised with an Ilizarov ring external fixator. The bone defect was partially shortened and restored by gradual transport of a bone segment created from proximal segments of the radius and ulna. The external fixator was removed 4fi months after the beginning of the latency period, due to instability caused by osteolysis around the wires. A cast was placed for 3 weeks. Although the bone transport had resulted in formation of approximately 4 cm of bone, the antebrachium showed approximately 50% shortening when compared to the contralateral limb. The infection was eradicated, and the dog was able to bear weight on the operated limb when walking.

Miniplate fixation for the repair of segmental mandibular defects filled with autogenous bone in cats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Some segmental features on the structure of the aortic wall of the dog

Structural features of segmental parts of the aorta of the dog were studied by light microscopy (LM) and scanning electron microscopy (SEM). The variability in the wall architecture composition and vascular thickness of the ascending (T2-3 level), thoracic (T7-8 level) and abdominal (L6-7 infrarenal level) segments of the aorta was analysed. Morphological features such as presence of intimal folds, pattern of the medial myoconnective components with segmental variations in the number of elastic lamellae, whose relative number was higher in the thoracic aorta (ascending and descending parts), compared with the abdominal aorta, and a network of connective (stromal) elements formed by elastic and collagen lamellae and fibres in the adventitia were observed. The results were discussed on a histophysiological basis, because small but significant segmental differences had been characterized in the aortic wall structure of the dog.

Assessment of bovine biomaterials containing bone morphogenetic proteins bound to absorbable hydroxyapatite in rabbit segmental bone defects

OBJETIVO: Avaliar a capacidade osteo-regenerativa de dois biomateriais utilizando um modelo de defeito segmentar efetuado nas diáfises do rádio de coelhos. MÉTODOS: O defeito direito foi preenchido com pool de proteínas morfogenéticas ósseas (pBMPs) e hidroxiapatita em pó ultrafina absorvível (HA) combinada com matriz óssea inorgânica desmineralizada e colágeno, derivados do osso bovino (Grupo A). O defeito esquerdo foi preenchido com matriz óssea desmineralizada bovina com pBMPs e hidroxiapatita em pó ultrafina absorvível (Grupo B). em ambos os defeitos utilizou-se membrana reabsorvível de cortical bovina desmineralizada para reter os biomateriais no defeito ósseo e guiar a regeneração tecidual. Os coelhos foram submetidos à eutanásia aos 30, 90 e 150 dias após a cirurgia. Foram efetuados exames radiográficos, tomográficos e histológicos em todos os espécimes. RESULTADOS: Aos 30 dias de pós-cirúrgico, o osso cortical desmineralizado foi totalmente reabsorvido em ambos os grupos. A HA tinha reabsorvido nos defeitos do Grupo A, mas persistiu nos do Grupo B. Uma reação de corpo estranho foi evidente com ambos os produtos, porém mais pronunciada no Grupo B. Aos 90 dias os defeitos do grupo B tinham mais formação óssea que os do Grupo A. Entretanto, aos 150 dias após a cirurgia, nenhum tratamento havia promovido o completo reparo do defeito. CONCLUSÃO: Os biomateriais testados contribuíram pouco ou quase nada para a reconstituição do defeito segmentar.