Clinically relevant estimation of minimal number of trials for the uncontrolled manifold analysis.

Movement biomarkers are crucial for assessing sensorimotor impairments and tracking the effects of interventions over time. The Uncontrolled Manifold (UCM) analysis has been proposed as a novel biomarker for evaluating movement stability and coordination in various motor tasks across neurological and musculoskeletal disorders. Through inter-trial analysis, the UCM partitions the variance of elemental variables (e.g., finger forces) into components that affect (VORT) and do not affect (VUCM) a performance variable (e.g., total force). A third index, ΔV, is computed as the normalized difference between VORT and VUCM. However, the minimum number of trials required to achieve stable UCM estimates, considering its clinimetric properties, is unknown. This study aimed to determine the minimal number (N) of trials for UCM estimates by computing bootstrap estimates of standard errors (SE) at different N trials using thresholds based on the minimal detectable change (MDC, i.e., the minimum change in an outcome measure beyond measurement error). Thirteen adults (24.6 ± 1.1 years old) performed a finger-pressing coordination task. We computed the 95 % confidence intervals (CI) of bootstrap SE distributions for each UCM estimate and detected the lowest number of trials with the 95 % CI of SE below each MDC threshold. We found the minimal N of trials required was VUCM = 14, VORT = 4 and ΔV = 18. Our findings highlight that a relatively low number of trials (i.e., N = 18) are sufficient to compute all UCM estimates beyond the MDC, supporting the use of the UCM framework in clinical settings where many repetitions of a motor task are not practical.

Descripción anatomopatológica de Pitiosis cutánea en equinos / Anatomopathological Description of Equine Skin Pythiosis

La presente investigación tuvo por objetivo describir macroscópica y microscópicamente, la pitiosis cutánea en el caballo criollo venezolano que habita la región de los llanos venezolanos en la zona correspondiente a los estados, Apure, Barinas y Portuguesa. Para ello, se realizaron visitas a distintos hatos durante los períodos de sequía y lluvioso, en el lapso comprendido entre enero 2008 a diciembre 2009. Se tomaron muestras de 8 animales con lesiones cutáneas compatibles con pitiosis, se realizó su descripción macroscópica y se obtuvieron varios fragmentos de tejido, los cuales se fijaron en formol buferado al 10%. Posteriormente, fueron procesadas para histopatología, coloreadas con hematoxilina y eosina, metenamina de plata de Grocott y finalmente se observaron bajo microscopia óptica. Todas las muestras presentaron hallazgos histopatológicos compatibles con pitiosis, lo cual fue confirmado a través de cultivo microbiológico. Los resultados obtenidos demostraron que la pitiosis cutánea es una enfermedad presente en el caballo criollo de los llanos venezolanos, caracterizada macroscópicamente por un aumento de volumen en forma de placa ulcerada, sangrante e irregular de color blanco amarillento, con apariencia de tejido de granulación, al corte superficial a profundo. Eventualmente, fueron halladas zonas de necrosis que contenían concreciones irregulares de color amarillento, duras, de superficie arenosa, que se correspondieron con las estructuras sólidas kunkers. Por otra parte, el estudio microscópico reveló una dermatitis granulomatosa, eosinofilica de difusa a multifocal.

An experimental research was conducted to describe both macroscopically and microscopically skin pythiosis in the Venezuelan Creole horse, which dwells in the Venezuelan plains of the States of Apure, Barinas, and Portuguesa. Visits were made to different farms between January 2008 and December 2009. Samples of eight horses with a skin disease consistent with skin pythiosis were taken and macroscopically analyzed. For the histopathological description, several tissue fragments were obtained and fixed in 10% buffer formalin. Subsequently, samples were stained with Hematoxylin-Eosin and Grocott’s silver methenamine, and observed under the light microscope. All samples showed histopathological findings consistent with skin pythiosis, which was confirmed through microbiological cultures. The results show that skin pythiosis is a dermatosis commonly seen in the Creole horse that populates the Venezuelan plains. Macroscopically, the lesions were characterized as irregular plaque-shaped, ulcerated, increased in volume, hemorrhagic, with a white-yellowish color, and a granulation tissue appearance, when examined both superficially and profoundly. Eventually, necrotic areas that contained irregular, yellowish, hard, sandy surfaces, which corresponded to kunker structures, were found. Conversely, the microscopic study revealed a diffuse to multifocal eosinophilic, granulomatous dermatitis.

Estudio hematológico y detección de hemoparásitos en caballos criollos venezolanos de dos hatos del Estado Apure, Venezuela / Hematological Study and Detection of Hemoparasites in Venezuelan Creole Horses from two Cattle Ranches, Edo. Apure, Venezuela

Los caballos criollos venezolanos son equinos autóctonos destinados a labores campestres, a los que no se les realiza comúnmente estudios hematológicos y seguimiento de ciertas patologías. Estos ejemplares representan un elemento de trabajo imprescindible para las faenas de arreo, aparte y captura de bovinos destinados a la producción de carne en el país. Las alteraciones hematológicas son un factor adverso para el rendimiento físico de la ganadería caballar en general y pudiera serlo también para equinos del llano venezolano. El propósito de la presente investigación fue establecer el estado hematológico y la presencia de hemoparásitos en caballos criollos venezolanos pertenecientes a dos hatos llaneros de los municipios Muñoz y Achaguas del Edo. Apure. Para ello se muestrearon 137 caballos obteniéndose 3,5 mL de sangre de la vena yugular en tubos con EDTA; la recolección de las muestras se realizó durante los meses de marzo y junio de 2008. Las pruebas realizadas consistieron en la determinación de la concentración de hemoglobina (Hb), porcentaje de hematocrito (Hto), la concentración de hemoglobina corpuscular media (CHCM), el recuento de glóbulos blancos (GB) y la fórmula leucocitaria diferencial, así como la determinación de hemoparásitos mediante las técnicas de Woo y frotis de capa blanca. Los resultados obtenidos fueron: Hb: 10,74 ± 4,56 g/dL, Hto: 31,17 ± 9,91%; CHCM: 34,21 ± 1,34%; GB: 16245 ± 6000 / mm³. Los caballos analizados presentaron valores de Hb y Hto disminuidos, CHCM normal, y leucocitosis marcada. Diferencias estadísticamente significativas se encontraron en las variables Hb y Hto en función al sexo (P<0,05). En el diagnóstico de hemoparásitos se observó formas parasitarias de T. evansi (7,3%), B. equi (1,4%) y A. phagocytophilum (32,9%).

Venezuelan creole horses are local species destined to typical farming works which hematological studies and control of certain pathologies are not commonly performed. These horses represent an essential element of work for tasks such as spurring, fetching and capturing bovines destined to beef production in the country. Hematological alterations are one of the main adverse factors to the physical performance of equines and it could be also impacting those horses located in Venezuelan farming areas (Venezuelan Valleys). The purpose of this research was to establish the haematological state and the presence of haemoparasites in Creole Venezuelan horses of two cattle ranches located in Apure State, specifically in Muñoz and Achaguas Municipalities. A total of 137 horses were sampled and 3.5 mL of blood from the jugular vein were taken in tubes with EDTA. Field sampling was performed in March and June 2008. Determinations of hemoglobin concentration (Hb), percentage of hematocrit (Hto), Corpuscular Hemoglobin Average Concentration (CHCM), white blood cells count (GB) and the leukocyte differential formulas were carried out, as well as the determination of haemoparasites by the technique of Woo and Buffy Coat. The results were as followed: Hb: 10.74 ± 4.56 g/dL, Hto: 31.17 ± 9.91%; CHCM 34.21 ± 1.34%; GB: 16245 ± 6000/mm³. Values obtained from analyzed horses’ blood showed decreased Hb and Hto, normal CHCM, and noticeable leucocytosis. Significant statistical differences were found in the variables Hb and Hto as a function of sex (P<0.05). T. evansi (7.3%), B. equi (1.4%) and A. phagocytophilum (32.9%) parasite forms were observed in the diagnosis of hemoparasites.

A simple recursive method for stationary receiver position estimation using GPS difference measurements.

This paper presents a simple recursive method to estimate the position of a stationary receiver using the difference of Global Positioning System (GPS) pseudorange measurements. In contrast to conventional Differential GPS (DGPS), the proposed simple method uses the difference of pseudorange measurements corresponding to a single receiver itself without requiring a fixed station with known location. The use of difference measurements reduces the effects of the various noise terms involved in pseudorange measurements. According to the proposed method, the position of the receiver is estimated recursively using an optimal linear approximation of the pseudorange nonlinear equations. The effectiveness of the proposed method is demonstrated on the estimation of the position of a stationary receiver, and its performance is compared to the performance of a classical approach. The results show that the proposed method outperforms the classical approach.