Qualitative Histologic Assessment vs. Geomorphometric Analysis of Nerve Fiber Shape after the Intraneural Application of Liposomal Bupivacaine / Evaluación Histológica Cualitativa Versus Análisis Geomorfométrico de la Forma de la Fibra Nerviosa Después de la Aplicación Intraneural de Bupivacaína Liposomal

SUMMARY: The preserved form of all components of the nerve fiber is a prerequisite for the proper conduction of the nerve impulse. various factors can change the shape of nerve fibers. In everyday practice, qualitative histological analysis is the gold standard for detecting changes in shape. Geometric morphometry is an innovative method that objectively enables the assessment of changes in nerve fibers' shape after local anesthetics action. A total of sixty sciatic nerves were used as material, which was intraneural injected with saline solution in the control group (n=30), and a solution of 1.33 % liposomal bupivacaine (n=30) in the test group. After the animals were sacrificed, nerve samples were taken and histological preparations were made. The preparations were first described and examined using a qualitative histological method, after which digital images were made. The images were entered into the MorphoJ program and processed using the method of geometric morphometry. Qualitative histological examination revealed no differences in nerve fibers after intraneurally applied physiological solution and liposomal bupivacaine. Using the method of geometric morphometry, a statistically significant change in the shape of axons was found after intraneurally applied saline solution and liposomal bupivacaine (p=0.0059). No significant differences in histological changes were found after the qualitative histological analysis of nerve fiber cross-section preparations. A statistically significant change in the shape of nerve fiber axons was observed after geometric morphometric analysis of digital images after intraneural application of saline and liposomal bupivacaine.

La forma conservada de todos los componentes de la fibra nerviosa es un requisito previo para la conducción correcta del impulso nervioso. Varios factores pueden cambiar la forma de las fibras nerviosas. En la práctica diaria, el análisis histológico cualitativo es el estándar de oro para detectar cambios de forma. La morfometría geométrica es un método innovador que permite evaluar objetivamente los cambios en la forma de las fibras nerviosas después de la acción de los anestésicos locales. Se utilizó como material un total de sesenta nervios ciáticos, que se inyectaron intraneuralmente con solución salina en el grupo control (n=30), y una solución de bupivacaína liposomal al 1,33 % (n=30) en el grupo de prueba. Después de sacrificados los animales, se tomaron muestras de nervios y se realizaron preparaciones histológicas. Primero se describieron y examinaron las preparaciones utilizando un método histológico cualitativo, después de lo cual se tomaron imágenes digitales. Las imágenes fueron ingresadas al programa MorphoJ y procesadas mediante el método de morfometría geométrica. El examen histológico cualitativo no reveló diferencias en las fibras nerviosas después de la aplicación intraneural de solución fisiológica y bupivacaína liposomal. Usando el método de morfometría geométrica, se encontró un cambio estadísticamente significativo en la forma de los axones después de la aplicación intraneural de solución salina y bupivacaína liposomal (p = 0,0059). No se encontraron diferencias significativas en los cambios histológicos después del análisis histológico cualitativo de las preparaciones de secciones transversales de fibras nerviosas. Se observó un cambio estadísticamente significativo en la forma de los axones de las fibras nerviosas después del análisis de morfometría geométrica de imágenes digitales después de la aplicación intraneural de solución salina y bupivacaína liposomal.

F approach algorithm in missing landmark problem / Aproximación al algoritmo F en punto de referencia perdido

SUMMARY: Missing data may occur in every scientific studies. Statistical shape analysis involves methods that use geometric information obtained from objects. The most important input to the use of geometric information in statistical shape analysis is landmarks. Missing data in shape analysis occurs when there is a loss of information about landmark cartesian coordinates. The aim of the study is to propose F approach algorithm for estimating missing landmark coordinates and compare the performance of F approach with generally accepted missing data estimation methods, EM algorithm, PCA based methods such as Bayesian PCA, Nonlinear Estimation by Iterative Partial Least Squares PCA, Inverse non-linear PCA, Probabilistic PCA and regression imputation methods. Landmark counts were taken as 3, 6, 9 and sample sizes were taken as 5, 10, 30, 50, 100 in the simulation study. The data are generated based on multivariate normal distribution with positively defined variance-covariance matrices from isotropic models. In simulation study three different simulation scenarios and simulation based real data are considered with 1000 repetations. The best and the most different result in the performance evaluation according to all sample sizes is the Min (F) criteria of the F approach algorithm proposed in the study. In case of three landmarks which is only the proposed F approach and regression assignment method can be applied, Min (F) criteria give best results.

RESUMEN: Los datos faltantes pueden ocurrir en todos los estudios científicos. El análisis estadístico de formas involucra métodos que utilizan información geométrica obtenida de objetos. La entrada más importante para el uso de información geométrica en el análisis estadístico de formas son los puntos de referencia. Los datos que faltan en el análisis de formas se producen cuando hay una pérdida de información sobre las coordenadas cartesianas históricas. El objetivo del estudio es proponer el algoritmo de enfoque F para estimar las coordenadas de puntos de referencia faltantes y comparar el rendimiento del enfoque F con métodos de estimación de datos faltantes generalmente aceptados, algoritmo EM, métodos basados en PCA como Bayesian PCA, Estimación no lineal por Iterative Partial Least Squares PCA, PCA no lineal inverso, PCA probabilístico y métodos de imputación de regresión. Los recuentos de puntos de referencia se tomaron como 3, 6, 9 y los tamaños de muestra se tomaron como 5, 10, 30, 50, 100 en el estudio de simulación. Los datos se generan en base a una distribución normal multivariada con matrices de varianza-covarianza definidas positivamente a partir de modelos isotrópicos. En el estudio de simulación se consideran tres escenarios de simulación diferentes y se consideran datos reales basados en simulación con 1000 repeticiones. El mejor y más diferente resultado en la evaluación del desempeño según todos los tamaños de muestra es el criterio Min (F) del algoritmo de enfoque F propuesto en el estudio. En el caso de tres puntos de referencia, que es solo el enfoque F propuesto y se puede aplicar el método de asignación de regresión, los criterios Min (F) dan mejores resultados.

Population structure of the Atlantic seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) based on geometric morphometrics / Estructura de la población del camarón langostino del atlántico Xiphopenaeus kroyeri (Heller, 1862) basada en morfometría geométrica

SUMMARY: In 2004, Xiphopenaeus kroyeri, one of major species in commercial fisheries in Brazil was included in the list of brazilian overfished species and, in 2006, two cryptic species were identified in the Atlantic Ocean by molecular approaches: Xiphopenaeus sp. I and II. In 2019, Carvalho-Batista et al. described both Xiphopenaeus sp. I and Xiphopenaeus sp. II and these species were named X. kroyeri and X. dincao, respectively. This study aimed at performing morphometric analysis in order to identify potential fishing stocks of X. kroyeri sensu strictum along Brazilian coast. The results obtained separate Caravelas, Atafona and Balneário Camboriú from all the other populations studied and showed three groups: Ubatuba, Nova Almeida; Ubatuba, Cananéia; Ubatuba, Santos. These results indicate that the maritime limits practiced in closed seasons along Brazil are embracing the detected morphometric stock boundaries observed for Xiphopenaeus kroyeris.s.

RESUMEN: En 2004, Xiphopenaeus kroyeri, una de las principales especies de la pesca comercial en Brasil, fue incluida en la lista de especies brasileñas sobre explotadas y, en 2006, se identificaron dos especies crípticas en el Océano Atlántico mediante enfoques moleculares: Xiphopenaeus sp. I y II. En 2019, Carvalho-Batista et al. describieron tanto Xiphopenaeus sp. I y Xiphopenaeus sp. II y a estas especies denominaron X. kroyeri y X. dincao, respectivamente. Este estudio tuvo como objetivo realizar un análisis morfométrico con el fin de identificar posibles poblaciones de pesca de X. kroyeri sensu strictum a lo largo de la costa brasileña. Los resultados obtenidos en Caravelas, Atafona y Balneário Camboriú se separaron de todas las demás poblaciones estudiadas y mostraron tres grupos: Ubatuba, Nova Almeida; Ubatuba, Cananéia; Ubatuba, Santos. Estos resultados indican que los límites marítimos practicados en temporadas de veda a lo largo de Brasil están abarcando los límites de stock morfométricos observados para Xiphopenaeus kroyeris.s.

Comparación y caracterización morfométrica del híbrido (Pseudoplatystoma metaense x Leiarius marmoratus) y sus parentales (Siluriformes: Pimelodidae) / Morphometric comparison and characterization of the hybrid (Pseudoplatystoma metaense x Leiarius marmoratus) and its parental lines (Siluriformes: Pimelodidae)

La diversificación en la oferta de la piscicultura, ha llevado a la hibridación de especies de alto valor comercial, como los grandes bagres de la familia Pimelodidae, en busca del mejoramiento de características relevantes. Sin embargo, uno de los principales problemas de ésta práctica, es que morfológicamente los híbridos son similares a los parentales o con formas intermedias difíciles de diferenciar. Las nuevas herramientas morfométricas como la geometría han logrado evaluar cuantitativamente los cambios morfológicos, coadyuvando a esclarecer problemas de diferenciación morfológica. Con el fin de evaluar las relaciones morfométricas y establecer si, las características analizadas son intermedias en el híbrido con respecto a los parentales, se realizó la caracterización morfométrica de 20 ejemplares adultos de Pseudoplatystoma metaense, 21 de Leiarius marmoratus y 12 del híbrido Pseudoplatystoma metaense x Leiarius marmoratus, para un total de 53 individuos evaluados. Se realizaron análisis de morfometría lineal, utilizando medidas corporales y craneales, sustentadas en los análisis de componentes principales y discriminantes, como una forma de evaluar el contorno de los ejemplares. Para el análisis osteológico, se utilizó el neurocráneo, obtenido mediante el protocolo de maceración; con fotografías, éstos fueron analizados mediante morfometría geométrica con los programas de la serie IMP. De esta forma, se encontró que las similitudes observadas a simple vista en el híbrido respecto a sus parentales, no son representativas y por lo tanto, estadísticamente se evidenciaron tres grupos morfológicos definidos que separan a las especies parentales y el híbrido, obteniendo así, una herramienta de fácil identificación. En el análisis osteológico, se encontraron similitudes entre los neurocráneos del híbrido y de Pseudoplatystoma metaense, lo que plantea un patrón de herencia en el que se pueden evaluar posibles convergencias y divergencias como consecuencia de la hibridación.

Diversification in the supply of fish farming has led to the hybridization of high commercial value species, such as the large catfish of the Pimelodidae family, in search of the improvement of relevant characteristics. However, one of the main problems of this practice is that morphologically the hybrids are similar to the parental lines or with intermediate forms difficult to differentiate. The new morphometric tools as geometry have managed to quantitatively evaluate the morphological changes, contributing to clarify problems of morphological differentiation. In order to evaluate the morphometric relationships and establish whether, the analyzed characteristics are intermediate in the hybrid with respect to the parental lines, the morphometric characterization of 20 adult specimens of Pseudoplatystoma metaense, was performed 21 of Leiarius marmoratus and 12 of the hybrid Pseudoplatystoma metaense x Leiarius marmoratus, for a total of 53 individuals evaluated. Linear morphometry analyses were performed, using body and cranial measurements, sustained in the analysis of principal and discriminating components, as a way of evaluating the contour of the specimens. For the osteological analysis, the neurocranium was used, obtained by means of the maceration protocol; with photographs; these were analyzed using geometric morphometry with the programs of the IMP series. Thus, it was found that the similarities observed at first sight in the hybrid with respect to their parentals, are not representative and therefore, statistically, three defined morphological groups that separate the parental species and the hybrid, thus obtaining an easy-to-identify tool. In the osteological analysis, similarities were found between the neurocraniums of the hybrid and Pseudoplatystoma metaense, which raises a pattern of inheritance in which possible convergences and divergences can be evaluated, as a result of hybridization.

Three-dimensional analysis of craniofacial shape in obstructive sleep apnea syndrome using geometric morphometrics / Análisis tridimensional de la forma craneofacial en el síndrome de apnea obstructiva del sueño mediante morfometría geométrica

SUMMARY: Craniofacial morphology is a risk factor for obstructive sleep apnea syndrome. The general aim of this study was to investigate the craniofacial shape differences in adults with and without obstructive sleep apnea syndrome, using geometric morphometric methods. A descriptive study conducted in 106 adult Turkish subjects, consisting of 50 patients with OSAS diagnosed by polysomnography and 56 non-OSAS controls. Three dimensional craniofacial scanning processes were performed on patient subjects on the same day as the PSG. Twelve standard craniofacial landmarks were collected from each subject's 3D craniofacial scan. Geometric morphometric analysis was used to compare the craniofacial shape differences between the OSAS and non-OSAS control groups. No statistically significant difference in terms of general shape in face shapes was found between the OSAS group and control group. However, local significance differences were found. There were significant differences between the groups in some of the interlandmark distances: 11 % of the interlandmark distances were greater in OSAS patients, and 29 % were greater in controls. Greater measured distances in OSAS are concentrated in the nasal region. In the control group, the difference is not concentrated in a specific region. Given the relationship of craniofacial structural alterations and sleep disordered breathing, we hypothesized that inter-landmark distance measurements in the craniofacial anatomy of patients might be predictive of OSA.

RESUMEN: La morfología craneofacial es un factor de riesgo para el síndrome de apnea obstructiva del sueño. El objetivo general de este estudio fue investigar las diferencias de forma craneofacial en adultos con y sin síndrome de apnea obstructiva del sueño utilizando métodos morfométricos geométricos. Un estudio descriptivo realizado en 106 sujetos turcos adultos, de 50 pacientes con SAOS diagnosticados mediante polisomnografía y 56 controles no SAOS. El proceso de escaneo craneofacial tridimensional se realizó en pacientes sujetos el mismo día que el PSG. Se recogieron doce puntos de referencia craneofaciales estándar del escaneo craneofacial 3D de cada sujeto. Se usó el análisis morfométrico geométrico para comparar las diferencias de forma craneofacial entre los grupos de control SAOS y no SAOS. No se encontraron diferencias estadísticamente significativas en términos de forma general en las formas de la cara entre el grupo SAOS y el grupo control. Sin embargo, se encontraron diferencias de significación local. Hubo diferencias significativas entre los grupos en algunas de las distancias interlandmark: el 11 % de las distancias interlandmark fueron mayores en los pacientes con SAOS y el 29 % en los controles. Las mayores distancias medidas en SAOS se concentran en la región nasal. En el grupo de control, la diferencia no se concentra en una región específica. Dada la relación de las alteraciones estructurales craneofaciales y la alteración de la respiración durante el sueño, planteamos la hipótesis de que las mediciones de distancias inter-hito en la anatomía craneofacial de los pacientes podrían ser predictivas de la SAOS.

Morphological differentiation between seven Brazilian populations of Haemagogus capricornii and Hg. janthinomys (Diptera: Culicidae) using geometric morphometry of the wings

Abstract INTRODUCTION: Haemagogus capricornii and Hg. janthinomys females are considered morphologically indistinguishable. We analyzed morphometric variability between Brazilian populations of these species using wing geometric morphometry. METHODS: Size and shape at intra- and interspecific levels were analyzed in 108 Hg. capricornii and Hg. janthinomys females. RESULTS: Geometric morphometry indicated size and shape variables can differentiate these species at interspecific level. However, at intraspecific level, results show relative differentiation. Two populations of Hg. capricornii had a smaller centroid size with no significant differences between them, whereas all Hg. janthinomys populations showed significant differences. CONCLUSIONS: Both species were correctly identified by geometric morphometry.

Where do these bugs come from? Phenotypic structure of Triatoma infestans populations after control interventions in the Argentine Chaco

House re-invasion by native triatomines after insecticide-based control campaigns represents a major threat for Chagas disease vector control. We conducted a longitudinal intervention study in a rural section (Area III, 407 houses) of Pampa del Indio, northeastern Argentina, and used wing geometric morphometry to compare pre-spray and post-spray (re-infestant bugs) Triatoma infestans populations. The community-wide spraying with pyrethroids reduced the prevalence of house infestation by T. infestans from 31.9% to < 1% during a four-year follow-up, unlike our previous studies in the neighbouring Area I. Two groups of bug collection sites differing in wing shape variables before interventions (including 221 adults from 11 domiciles) were used as a reference for assigning 44 post-spray adults. Wing shape variables from post-spray, high-density bug colonies and pre-spray groups were significantly different, suggesting that re-infestant insects had an external origin. Insects from one house differed strongly in wing shape variables from all other specimens. A further comparison between insects from both areas supported the existence of independent re-infestation processes within the same district. These results point to local heterogeneities in house re-infestation dynamics and emphasise the need to expand the geographic coverage of vector surveillance and control operations to the affected region.

Evidence of incipient speciation in astyanax scabripinnis species complex (teleostei: characidae)

Two populations of the Astyanax scabripinnis complex, isolated by a waterfall with over 100 meters depth and inhabiting different altitudes of the same river (1850 m a.s.l. and 662 m a.s.l.) were compared in reproductive data, geometric morphometry, tooth morphology, anal-fin rays counts, and karyotype, in order to test the hypothesis of speciation between the two populations. The results in the geometric morphometry analysis showed differences between the populations. Discriminant function analysis (DFA) and canonical variance analysis revealed sexual dimorphism. Secondary sexual characters, such as hooks in the anal fin rays of the males are absent in the lower altitude population. Both populations had the same macro karyotype structure, except for the absence of B chromosomes in the lower altitude population. The fluorescence in situ hybridization showed differences for both markers (18S rDNA and 5S rDNA), and reproductive data suggests pre-zygotic reproductive isolation among the two populations. The data showed the absence of gene flow, indicating that an incipient speciation process has occurred, which leads the two populations to follow independent evolutionary pathways.

Duas populações do complexo Astyanax scabripinnis isoladas por uma queda d´água de mais de 100 metros de altura e localizadas em diferentes altitudes do mesmo rio (662 m e 1850 m a.s.l.) foram comparadas através de dados de reprodução, cariótipo, morfometria geométrica, morfologia dentária, e número de raios da nadadeira anal, de modo a testar a hipótese de especiação entre as duas populações. Os resultados de morfometria geométrica mostraram diferenças entre as populações. A análise da função discriminante (DFA) e a análise de variância canônica (CVA) demonstraram a presença de dimorfismo sexual. Caracteres sexuais secundários, como ganchos em raios da nadadeira anal dos machos, estão ausentes na população de menor altitude. Ambas as populações têm a mesma macro estrutura cariotípica, exceto pela ausência de cromossomos B na população de menor altitude. A hibridação in situ mostrou diferenças para ambos os marcadores (rDNA 18S e rDNA 5S), e os dados de reprodução sugerem isolamento reprodutivo pré-zigótico entre as duas populações. Os dados mostram ausência de fluxo gênico, indicando que ocorreu um processo de especiação incipiente, o que leva as duas populações seguirem vias evolutivas independentes.