Abstract Fishing products are characterized for being highly perishable; therefore, preservation methods are used to retain freshness, quality and extend shelf life. One of the factors that influences most on the loss of freshness, quality and shelf life, is storage temperature. This study evaluated the effect of storage temperature (0 °C and 5 °C) on the quality and shelf life of tilapia (Oreochromis niloticus) muscle during 20 days of storage. Adenosine 5’-triphosphate (ATP) and related compounds, K-value, pH, color, texture, water holding capacity (WHC), total volatile bases (TVB-N), and total count of mesophilic microorganisms were monitored. The results indicated that time and storage temperature had a significant effect (P < 0.05) on K-value, TVB-N, and total count of mesophilic microorganisms. The present study concludes that, by storing tilapia muscle at a lower temperature, a longer shelf life is produced, which implies that the product can be kept with good quality for a longer period of time. Likewise, the edible quality of tilapia muscle was affected by storage temperature, observing a shelf life of 16 days at 0 °C and 8 days at 5 °C.

Resumen Los productos pesqueros se caracterizan por ser altamente perecederos; por lo tanto, se utilizan métodos para conservar la frescura, la calidad y extender la vida útil. Uno de los factores que más influye en la pérdida de frescura, calidad y vida útil es la temperatura de almacenamiento. Este estudio evaluó el efecto de la temperatura de almacenamiento (0 °C y 5 °C) sobre la calidad y vida útil del músculo de tilapia (Ore ochromis niloticus) durante 20 días de almacenamiento. Se monitorearon el ATP (adenosina-5’-trifosfato) y compuestos relacionados, el indice K, el pH, el color, la textura, la capacidad de retención de agua (CRA), las bases volátiles totales (TVB-N) y el recuento total de microorganismos mesófilos. Los resultados indicaron que el tiempo y la temperatura de almacenamiento tuvieron un efecto significativo (P < 0.05) sobre el indice K, TVB-N y el recuento total de microorganismos mesófilos. En el presente estudio se concluye que al almacenar el músculo de tilapia a menor temperatura se produce una mayor vida útil, lo que implica que el producto se puede conservar con buena calidad por más tiempo. Asimismo, la calidad comestible del músculo de tilapia se vio afectada por la temperatura de almacenamiento, observándose una vida útil de 16 días a 0 °C y 8 días a 5 °C.

Abstract The aim of this research was to evaluate the effect of storage temperature (0 and 5°C) on the main metabolites and related parameters to rigor mortis in muscle of tilapia (Oreochromis niloticus). The rigor index (IR), adenosine 5’-triphosphate (ATP), glycogen, lactic acid, pH and texture were evaluated. The IR analysis was performed during 266 hours of storage at the two temperatures, while the rest of the parameters were monitored at 0 and at 48 hours of storage at both temperatures. It was found that both temperature and storage time, had a significant effect on IR, being more pronounced at 5°C compared to 0°C.

Resumen El objetivo de la presente investigación fue evaluar el efecto de la temperatura de almacenamiento (0 y 5ºC) sobre los principales metabolitos y parámetros relacionados con el rigor mortis del músculo de tilapia (Oreochromis niloticus). Se evaluó el índice de rigor (IR), adenosina 5´-trifosfato (ATP), glucógeno, ácido láctico, pH y textura. El análisis del IR se realizó durante 266 h de almacenamiento a las dos temperaturas, mientras que el resto de los parámetros se monitorearon al tiempo 0 y a las 48 h de almacenamiento en ambas temperaturas. Se encontró que tanto la temperatura como el tiempo de almacenamiento presentaron un efecto significativo sobre el IR, siendo más pronunciado a 5°C en comparación al de 0°C.

Abstract The aim of this study was to evaluate the effects of chitosan-tomato plant extract (C-TPE) edible coating (EC) applications on the physicochemical, microbiological, sensory and antioxidant capacity of chicken during storage. Edible coatings prepared with chitosan 1%, acetic acid 1%, glycerol and TPE (0.1 and 0.3%) were tested. The slices were submerged for 1 minute in different treatments (T1: C 1%; T2: C 1% + TPE 0.1%; T3: C 1% + TPE 0.3%; T4: control) and stored at 4 °C. At the end of the storage period, the treatments exhibited the greatest physicochemical and microbiological effects in the slices, reducing the microbial population relative to the control. The T2 treatment exhibited the highest antioxidant capacity, total phenolic content and overall acceptance. The results demonstrate that the application of C with the addition of a natural extract, such as those from the tomato plant, can be an alternative method for preserving chicken meat.

ABSTRACT: In order to infer patterns of coexistence and trophic segregation for temperate forest birds in three elevations of the San Bernardino Basin, State of México, trophic tracking of insectivorous birds was carried out from October 2016 to January 2017. Cut-shaking of branches, intensive searches, mist nets, excreta analysis and insect identification were used. Frequency of observation analysis (Fo), Poisson regression (PRA), X2, the Kruskal-Wallis test and simple correspondence analysis (SCA) were used. The overall average valué for Fo indicates that the most used hunting technique is to collect (Fo = 91%) and for PRA to collect and remove (Pr > Z = -7.291, 0.929). The orders of insects consumed are Coleóptera and Hymenoptera (Pr > Z = < 13, 6.959). The X2 shows that what was recorded is similar to what was expected (Prob > Chisq = 0.572 1, 0.247 4, 0.295 6, 0.508 9). Kruskal-Wallis shows that hunting-diet techniques are similar (Prob > Chi square = 0.537 1, 0.262 2, 0.180 9, 0.466 5). The SCA shows coexistence in the formation of four avifaunal groups (Inertia = 100, 47.87, 28.84, 83.15%; hunting techniques, orders, families, types of insects, respectively). Elevation is not a determinant of trophic coexistence, since it does not affect the availability of prey, so it does not modify the hunting techniques used by birds, exhibiting similar diets, with trophic sympatry. Habitat improvement strategies that promote the availability of prey for this type of bird are recommended.

RESUMEN: Con el objetivo de inferir patrones de coexistencia y segregación trófica para aves de bosque templado en tres elevaciones de la Cuenca de San Bernardino, Estado de México. Se realizó el seguimiento trófico de aves insectívoras de octubre de 2016 a enero de 2017. Se emplearon corte-sacudida de ramas, búsqueda Intensiva, redes de niebla, análisis de excretas e identificación de insectos. Se utilizaron análisis de frecuencia de observación (Fo), regresión de Poisson (ARP), X2; Kruskal-Wallis y correspondencia simple (ACS). El valor general promedio para Fo señala que la técnica de cacería más utilizada es colectar (Fo = 91%) y para ARP colectar y remover (Pr > Z = -7.291, 0.929). Los órdenes de insectos consumidos son Coleóptera e Hymenoptera (Pr > Z = < 13, 6.959). La X2 muestra que lo registrado es similar a lo esperado (Prob > Chisq = 0.572 1, 0.247 4, 0.295 6, 0.508 9). Kruskal-Wallis evidencia que las técnicas de cacería-dieta son similares (Prob > Ji cuadrado = 0.537 1, 0.262 2, 0.180 9, 0.466 5). El ACS muestra coexistencia en la formación de cuatro grupos avifaunísticos (Inercia = 100, 47.87, 28.84, 83.15%; técnicas de cacería, ordenes, familias, tipos de insectos, respectivamente). La altitud no es un factor determinante de coexistencia trófica, ya que no afecta la disponibilidad de presas, por lo que no modifica las técnicas de cacería utilizadas por las aves, exhibiendo dietas similares, con simpátria trófica. Se recomiendan estrategias de mejoramiento de hábitat que promuevan la disponibilidad de presas para éste tipo de aves.

Abstract Fish consumption has increased in recent years. However, fish meat is highly perishable, which demonstrates the need for technologies to preserve its quality. Edible coatings (EC) might provide an alternative to extend the shelf life of fish. The goal of this study was to evaluate the effect of EC of chitosan (C) in combination with carvacrol (CAR) on the physical and microbiological changes of tilapia fillets. Fillets were submerged for two minutes in different treatments (T1: control; T2: C 2%; T3: C 2% + 0.125% CAR; T 4: C 2% + 0.25% CAR). At the end of storage, T1 and T2 showed the lowest values of total volatile bases (TVB). The color parameters L*, a* and b* varied from each treatment. The texture decreased and the different treatments reduced the microbial population in relation to the control; T3 and T4 were the most effective. These results show that the use of C with CAR might be an alternative method to preserve the quality and safety of tilapia fillets.

Introduction. Möebius syndrome (MS) is a rare congenital disease of multifactorial etiology; VI and VII cranial nerves or their nucleus are involved in its clinical presentation, with facial diplegia and inability to abduct the eyes beyond the midline; other cranial nerves are also involved. As far as 90% of patients have normal intelligence. Objective: to describe the characteristics of seizure in children with MS and epilepsy. Material and methods. A descriptive retrolective study of children with MS attended in the Hospital Infantil de Mexico Federico Gomez from 1994 to 2004. Clinical characteristics of seizures were determined. Results. Thirty one patients with MS were analyzed; of these, 8 had epilepsy (25.8%), 2 cases (6.4%) partial epilepsy, 4 cases (12.9%) generalized epilepsy; one case (3.22%) with epilepsy plus and 1 case (3.22%) with infantile spasms. In 7 of 8 cases of epilepsy, the EEG was abnormal and there were multiple abnormalities in neuroimaging. Conclusion. Epilepsy in children with MS is probably determined by other associated diseases, it is not the result of MS itself.

Introducción. El síndrome de Möebius (SM) es una enfermedad congénita, sin etiología determinada, multifactorial, se considera rara y se caracteriza por la afección del VI y VII pares craneales o sus núcleos, es unilateral o bilateral, teniendo como manifestación clínica diplejía facial con limitación de la mirada lateral. Se describe en literatura más reciente la afección de otros pares craneales. Hasta 90% de los casos tienen inteligencia normal. Objetivo: determinar las características de las crisis convulsivas de los pacientes con SM y epilepsia. Material y métodos. Estudio descriptivo, analítico y retrolectivo, en el cual se revisaron los casos registrados con diagnóstico de SM en el Hospital Infantil de México Federico Gómez, en el período de 1994-2004, analizando las diferentes variables y revisando las causas de la epilepsia en estos pacientes. Resultados. De 31 pacientes con SM, se encontraron 8 con epilepsia (25.8%): 2 casos (6.4%) con epilepsia parcial, 4 (12.9%) con epilepsia generalizada, 1 caso (3.22%) con crisis febriles plus y 1 caso (3.22%) con espasmos infantil. En 7 de los 8 casos de epilepsia, el EEG fue anormal, así como la neuro-imagen donde se observaron múltiples anormalidades. Conclusiones. La epilepsia en pacientes con SM depende más de la asociación de éste con otras enfermedades que del síndrome en sí, por lo cual el riesgo de epilepsia en estos pacientes está asociado a la etiología acompañante del SM.