Motor Point as an Alternative to Femoral Nerve Stimulation for the Assessment of Quadriceps Muscle Inhibition in Healthy Women.

CONTEXT: The evaluation of quadriceps muscle inhibition with the interpolated twitch technique is usually performed by stimulating the femoral nerve (FN). However, there are some problems related to the use of this stimulation site, which may be partially overcome by delivering the stimulation over the motor point (MP). This study sought to compare MP to FN stimulation at different joint angles for the evaluation of quadriceps muscle inhibition, resting peak torque, and discomfort in healthy women. DESIGN: Cross-sectional study. METHODS: Sixteen healthy women (age: 28 [4] y; body mass: 60 [5] kg; height: 162 [5] cm) participated in this study. Supramaximal paired stimuli were delivered to the FN and to the rectus femoris MP before and during maximal voluntary contractions at different knee angles (15°, 30°, 45°, 60°, and 90° of knee flexion) to assess muscle inhibition and resting peak torque. Discomfort was also recorded for each stimulation site and knee angle. RESULTS: Muscle inhibition was similar between the 2 stimulation sites (P > .05) and was higher at 45° than at 90° (P = .03). MP stimulation evoked lower resting peak torque at 30° (P = .004), 60° (P = .006), and 90° (P = .006) and higher discomfort at 30° (P = .008) and 90° (P = .027) compared to FN stimulation. CONCLUSIONS: Despite lower resting peak torque and higher discomfort at some angles, MP stimulation provided similar muscle inhibition to FN stimulation at all knee angles and is therefore a valid method to evaluate quadriceps muscle inhibition in healthy women. MP stimulation can be used as an alternative to FN stimulation for the evaluation of quadriceps muscle inhibition with no added discomfort at the angles where muscle inhibition is the highest.

An R Script to Estimate Which and How Many Landmarks Represent the Most Variable Parts of an Object / Un Script R para Estimar Cuáles y Cuántos Puntos de Referencia Representan las Partes más Variables de un Objeto

SUMMARY: The study of the shape variation in geometric morphometrics has an important limitation known as the Pinocchio effect. The Pinocchio effect produces artifactual variances of the landmarks and implies that it is not possible to know the morphological change structure of an object, other than by dividing the landmark sets and then comparing them. This, however, involves making prior assumptions about the pattern of variation of an object. In this study, we provide a code in R to iterate over a complete set of landmarks and test all possible combinations of landmarks until deliver those landmarks associated with the largest to the smallest morphological changes. We tested this on a sample of 28 landmarks in 143 3D models of human skulls. The results indicated that this process can result in a pooled variance of a subset of landmarks that is an order of magnitude larger than that of several other regions of the skull. This method makes it possible to describe the pattern of variation of any 2D or 3D object represented by fixed landmarks, to distinguish the shape features that have more morphological dispersion, and to avoid any aprioristic assumptions about how the morphological changes of an object behave.

El estudio de la variación de la forma en morfometría geométrica tiene una limitación importante conocida como efecto Pinocho. El efecto Pinocho produce variaciones artefactos de los puntos de referencia e implica que no es posible conocer la estructura del cambio morfológico de un objeto, salvo dividiendo los conjuntos de puntos de referencia y luego comparándolos. Sin embargo, esto implica hacer suposiciones previas sobre el patrón de variación de un objeto. En este estudio, proporcionamos un código en R para iterar sobre un conjunto completo de puntos de referencia y probar todas las combinaciones posibles de puntos de referencia hasta entregar aquellos puntos de referencia asociados con los cambios morfológicos más grandes a los más pequeños. Probamos esto en una muestra de 28 puntos de referencia en 143 modelos 3D de cráneos humanos. Los resultados indicaron que este proceso puede dar como resultado una variación combinada de un subconjunto de puntos de referencia que es un orden de magnitud mayor que el de varias otras regiones del cráneo. Este método permite describir el patrón de variación de cualquier objeto 2D o 3D representado por puntos de referencia fijos, distinguir las características de forma que tienen más dispersión morfológica y evitar suposiciones apriorísticas sobre cómo se comportan los cambios morfológicos de un objeto.

Development of craniofacial superimposition: a review / Desarrollo de la superposición craneofacial: una revisión

SUMMARY: Craniofacial superimposition is a method for identifying individuals by using secondary data in order to identify a target group of persons before a DNA process can be used, or to identify an individual instead of using primary data in cases where DNA, fingerprint or dental records are not found. Craniofacial superimposition has continued to evolve, with various techniques, including computer-assisted and photography techniques, to help the operation be more convenient, faster and reliable. The knowledge of forensic anthropology is applied, with a comparison between anatomical landmarks. The study of developments in craniofacial superimposition using computer-assistance has yielded satisfactory results.

La superposición craneofacial es un método para identificar individuos mediante el uso de datos secundarios, se utiliza para identificar un grupo objetivo de personas, antes de que se pueda utilizar un proceso de ADN, o para identificar a un individuo en lugar de utilizar datos primarios en los casos en que no se cuenta con registros de ADN, huellas dactilares o dentales. La superposición craneofacial ha seguido evolucionando, con diversas técnicas, incluidas las técnicas fotográficas y asistidas por computador, para ayudar a que la operación sea más conveniente, rápida y confiable. Se aplica el conocimiento de la antropología forense, con una comparación entre hitos anatómicos. El estudio de la evolución de la superposición craneofacial con asistencia informática ha arrojado resultados satisfactorios.

Four decades of socio-economic inequality and secular change in the physical growth of Guatemalans.

OBJECTIVE: To investigate changes in socio-economic inequalities in growth in height, weight, BMI and grip strength in children born during 1955-1993 in Guatemala, a period of marked socio-economic-political change. DESIGN: We modelled longitudinal data on height, weight, BMI and hand grip strength using Super-Imposition by Translation and Rotation (SITAR). Internal Z-scores summarising growth size, timing and intensity (peak growth velocity, e.g. cm/year) were created to investigate inequalities by socio-economic position (SEP; measured by school attended). Interactions of SEP with date of birth were investigated to capture secular changes in inequalities. SETTING: Urban and peri-urban schools in the region of Guatemala City, Guatemala. PARTICIPANTS: Participants were 40 484 children and adolescents aged 3-19 years of Ladino and Maya ancestry (nobservations 157 067). RESULTS: The difference in height (SITAR size) between lowest and highest SEP decreased from -2·0 (95 % CI -2·2, -1·9) sd to -1·4 (95 % CI -1·5, -1·3) sd in males, and from -2·0 (95 % CI -2·1, -1·9) sd to -1·2 (95 % CI -1·3, -1·2) sd in females over the study period. Inequalities also reduced for weight, BMI and grip strength, due to greater secular increases in lowest-SEP groups. The puberty period was earlier and shorter in higher-SEP individuals (earlier SITAR timing and higher SITAR intensity). All SEP groups showed increases in BMI intensity over time. CONCLUSIONS: Inequality narrowed between the 1960s and 1990s. The lowest-SEP groups were still >1 sd shorter than the highest. Risks remain for reduced human capital and poorer population health for urban Guatemalans.

Fusión de imágenes y protección de hipocampo para el tratamiento de metástasis cerebrales con radioterapia / Image fusion and hippocampus protection in radiotherapy treatment of brain metastases

Las imágenes de simulación obtenidas mediante TAC son actualmente el estándar para uso en los sistemas de planificación de haces externos empleados en los tratamientos de radioterapia. Sin embargo, una de las limitaciones es su bajo contraste y poca especificidad para la identificación y caracterización de lesiones tumorales y algunas estructuras a nivel de sistema nervioso central. Los nuevos algoritmos implementados en los sistemas de planificación de radioterapia permiten realizar la fusión de imágenes de RM con TAC de simulación, definir y proteger estructuras como el hipocampo, buscando administrar dosis bajas en esta zona, lograr mayores dosis a los volúmenes tumorales y disminuir los efectos secundarios derivados de tratamientos holoencefálicos con radioterapia. En este artículo se presentan las imágenes correspondientes a esta técnica de tratamiento.

CT simulation images are the current standard in external beam radiotherapy planning systems. However, the limitations of images obtained from CT scanning include their low contrast and low specificity in the identification and characterization of tumor lesions and some central nervous system structures. The new algorithms implemented in radiotherapy planning systems allow image fusion to be performed using MRI images and CT simulation images. It also allows structures like the hippocampus to be defined and protected, by administering lower Radiosurgery; doses to this area and higher doses to the tumor volume, thus decreasing side effects arising from whole brain radiotherapy treatment. Images corresponding to this treatment technique are presented in this article.

Método de superposición estructural de Björk para evaluar crecimiento y desarrollo craneofacial / Björk structural superimposition method to evaluate craniofacial growth and development

La superposición cefalométrica es una herramienta indispensable en la práctica de la Ortodoncia ya que permite evaluar los cambios que sufre el complejo craneofacial a través del proceso de crecimiento y desarrollo o aquellos cambios logrados mediante un tratamiento. En la literatura se han descrito múltiples técnicas de superposición cefalométrica; la mayoría de ellas utilizan como puntos de referencia zonas anatómicas poco estables durante el periodo de crecimiento y desarrollo. El doctor Björk describió una técnica de superposición cefalométrica basada en estudios con implantes metálicos, lo cual permitió identificar puntos de referencia y zonas anatómicas mas estables durante este periodo, por lo que permite medir y valorar los cambios craneofaciales de una manera mas confiable. El Objetivo de este articulo es describir la técnica de superposición estructural de Björk para su utilización como herramienta en la practica clínica e investigativa de la Ortodoncia.

Cephalometric superimposition is a critical tool in Orthodontics when evaluating changes affecting the craniofacial complex through the process of growth and development, or those obtained with treatment. Several cephalometric superimposition techniques have been reported previously, but most of them use unstable anatomical landmarks as reference areas or points to establish changes during growth and development. Björk's method describes a cephalometric superimposition technique based on studies with metal implants which allowed to identify stable reference points during the growth and therefore enable the possibility of measuring and evaluating craniofacial changes in amore reliable manner. The objective of this article is to describe Björk structural superimposition method as a tool in clinical practice and research in Orthodontics.

Fotogrametría del perfil facial en ortodoncia / Photogrammetry of facial profile in orthodontics

Se incorporaron dos sencillos elementos en las fotografías del perfil facial en ortodoncia. La aplicación de un sello, automático, de tinta común con una escala preestablecida de aplicación fácil, ágil y reproducible, directamente sobre la piel del paciente, para otorgar mayorprecisión en la comparación de imágenes en el tiempo; como así también, la utilización de un plano de referencia denominado plano lefraconformado por dos puntos que unen ojo y oído, permitiendo evaluar los cambios producidos en el rostro por medio de la superposición fotográfica. Al finalizar el presente trabajo se concluyo que la utilización del sello y la superposición sobre el plano lefra permiten asimilar eltamaño de las fotografías y a su vez dar una zona referencial estable, facilitando la comparación entre el pre y post tratamiento.

Two simple elements were incorporated in the photographs of facial profile in orthodontics. The application of a seal, automatic, common ink on a prescribed scale of easy, fast and reproducible application, directly on the skin of the patient profile, which gives more accurate comparison of images in time; as well as the use of a reference plane called lefra plane, which consists of two points linking eye and ear, allowing to evaluate the changes in the face by means of photographic superimposition. Upon completion of this work, was concluded that the use of the seal and the overlay on the lefra plane allow to assimilate the size of the photographs and in turn provide a stable reference area to facilitate the comparison between pre and post treatment.

Assessing Nonverbal Same/Different Judgments of Auditory Stimuli in Individuals with Intellectual Disabilities: A Methodological Investigation.

This methodological paper reports an initial attempt to evaluate the feasibility and utility of a nonverbal task for assessing generalized same/different judgments of auditory stimuli in individuals who have intellectual disabilities. Study 1 asked whether participants could readily acquire a baseline of auditory same/different, go-left/go-right performance with minimal prompting. Sample stimuli consisted of pairs of successively presented sine-wave tones. If the tones were identical, participants were reinforced for selections of a visual stimulus on the left side of the computer screen; if the two stimuli were different, selections of the visual stimulus on the right were reinforced. Two of five participants readily acquired the task, generalized performance to other stimuli and completed a rudimentary protocol for examining auditory discriminations that are potentially more difficult than those used to establish the initial task. In Study 2, two participants who could not perform the go-left/go-right task with tone stimuli, but could do so with spoken-word stimuli, successfully transferred control by spoken words to tones via an auditory superimposition-and-fading procedure. The findings support the feasibility of using the task as a general-purpose auditory discrimination assessment.

Avaliação das estruturas anatômicas para sobreposição cefalométrica maxilar utilizando telerradiografias em norma de 45 graus / Anatomical structures evaluation to maxillary cephalometric superimposition using 45º cephalometric radiography

Um estudo cefalométrico longitudinal e retrospectivo foi desenvolvido com o propósito de estabelecer um cefalograma para a maxila, encontrar pontos cefalométricos estáveis na telerradiografia em norma de 45 graus, e ainda avaliar se as imagens obtidas de um lado da radiografia oblíqua são compatíveis com o outro lado. Foram selecionadas telerradiografias em norma de 45 graus de 25 indivíduos, com faixa etária entre 12 e 17 anos, apresentando maloclusões de Classe I e Classe II de Angle. Todos os indivíduos possuíam radiografias oblíquas iniciais e finais dos lados direito e esquerdo tomadas em um mesmo aparelho de raios X, com um intervalo de 8 a 16 meses. O principal critério de inclusão era a presença de implantes metálicos em todas as telerradiografias , para sobreposições dos traçados cefalométricos. Após estudos em crânio seco e inspeção visual foi sugerido um cefalograma para a maxila constituído das seguintes estruturas anatômicas: contorno da órbita, uma linha da base do crânio, a região do processo zigomático, limites de seio maxilar, a maxila, o processo zigomático da maxila do lado oposto, o osso zigomático do lado oposto e a órbita do lado oposto. Os pontos cefalométricos sugeridos para servir de parâmetro na sobreposição parcial da maxila, em telerradiografias em norma de 45 graus, foram divididos de acordo com o sentido analisado. No sentido vertical os pontos mais estáveis foram: OS, PZI, ENP e PZMO. No sentido horizontal os pontos sugeridos foram: PZP, PZPI, PZI, ENA e A. As alterações anatômicas ocorridas em todos os pontos cefalométricos do lado esquerdo foram iguais as do lado direito, não havendo diferença entre os lados da tomada radiográfica para telerradiografias em norma de 45 graus

A longitudinal and retrospective cephalometric study was developed in order to establish a maxillary cephalogram, to identify stable cephalometric landmarks on 45° radiographs, as well as to evaluate if the obtained images from one side are compatible with the ones from the other side. Forty-five degrees cephalometric radiographs of 25 persons, aged between 12 and 17 years, presenting Angle malocclusion: Class I and Class II were selected. All the persons had pre and post right and left oblique radiographs obtained from the same X ray device, with an interval of eight to sixteen months. The primary inclusion criterion was the presence of metallic implants in all radiographs, to obtain the cephalometric tracings superimpositions. After studies in dried skulls and visual inspection, a maxillary cephalogram was suggested using the following anatomical structures: the orbital contour, a cranial base line, the zigomatic process area, maxillary sinus boundaries, the maxilla; the maxillary zygomatic process, zigomatic bone and orbit of the counter side. The cephalometric landmarks suggested to work parameter for maxillary superimposition in 45º cephalometric radiographs were separated in accordance with the evaluated plane. It can be suggested the use of OS, PZI, PNS and PZMO on vertical planes and PZP, PZPI, PZI, ANS and A on horizontal plane considered the points more stable and reproducible in the sample. The anatomical changes observed in all the cephalometric points of the left side were equivalent to the ones of the right side, with no differences between the sides on 45º cephalometric radiographs