ABSTRACT The curve of cumulative cases of individuals infected by COVID-19 shows similar growth to the logistic curve in the period referring to each epidemic “wave”, as each peak of active cases is called. Considering that in pandemic scenarios it is common to seek control measures based on previous experiences, in this paper we model the curve of cumulative cases through a logistic model with infected removal to include the control measures in the dynamics. This model is based on fractional differential equations to also include the memory effect. We study the scenario of the first two “waves” in the analyzed countries: Brazil, China, Italy, and Switzerland. Scenarios with and without control measures are compared, proving the importance of control measures such as isolation. Moreover, this model makes it possible to determine the portion of the population that did not participate in the dynamics of the spread of the disease, as well as to analyze how the number of infected people reduced in each country.

Abstract We present our recently-built experimental setup designed to generate near-infrared and narrow-band correlated photon pairs by inducing four-wave mixing in a cold gas of 87Rb atoms confined in a magneto-optical trap. The experimental setup and its automation and control approach are described in detail. A characterization of the optical density of the atomic ensemble as well as the basic statistical measurements of the generated light are reported. The non-classical nature of the photon pairs is confirmed by observing a violation of Cauchy-Schwarz inequality by a factor of 5.6 × 10-5 in a Hanbury Brown - Twiss interferometer. A 1/e coherence time for the heralded, idler photons of 44 ± 0.1 ns is estimated from our observations. We are able to achieve a value of 104 s-1 pair-detection-rate, which results in a spectral brightness of 280 (MHz s)-1. The combination of high brightness and narrow-band spectrum makes this photon-pair source a viable tool in fundamental studies of quantum states and opens the door to use them in quantum technologies.

ABSTRACT The effect of including partially dehulled sunflower seeds in the diet of grazing chickens in meat quality was evaluated. Two hundred and forty, one-day-old, Ross 308 chickens were used, randomly distributed into four treatments with six replicates of 10 birds each. Seventy-two birds were slaughtered at seven weeks of age, 18 per treatment, extracting the Pectoralis major muscle to analyze meat quality. The treatments were completely randomized in a 2x2 factorial arrangement, where type of rearing (confinement or grazing) and diet (base diet or base diet substituting 10% soybean meal for partially dehulled sunflower seeds) were the independent variables. The grazing chickens spent 8 hours a day in a white clover (Trifolium repens) paddock. Including sunflower seeds improved (p<0.05) the color and crude protein (CP) in breast meat (p<0.05), while grazing increased (p<0.05) CP, dry mater (DM), and shear force (SF), and the percentage of breast fat decreased (p<0.05) by up to 50%. Additionally, grazing increased (p<0.05) saturated fatty acids (SFA) and reduced (p<0.05) lipid oxidation by up to 50%. Partially replacing soybean meal with partially dehulled sunflower seeds in the diet of grazing chickens with white clover improves the physicochemical characteristics and nutritional quality of the breast meat; it also decreases lipid oxidation, extending the shelf life of the meat.

Tannins are polyphenolic compounds with some beneficial properties for ruminants as they act as antioxidants, antimicrobials, and anthelmintics, which may improve animal performance. However, the results are variable, depending on the type, source, and dose. The objective of this research was to determine the effect on fattening performance and carcass characteristics of lambs supplemented with condensed tannins (CTs) from Acacia mearnsii extract. Thirty-six, three-month-old Dorset x Hampshire cross lambs of 20.8 ± 3.3 kg live weight were used in a completely randomized design with four treatments (n = 9), namely T1: basal diet, 0.0 g CT/kg DM-1; T2: T1 + 1.75 g CT/kg DM-1; T3: T1 + 3.5 g CT/kg DM-1; and T4: T1 + 5.25 g CT/kg DM-1. The daily weight gain was higher in T2 and T3 than in T1. The weight at slaughter and empty weight at slaughter were higher in T2 than in T1. The hot carcass weight was higher in T3 than in T1, but no different from T2 or T4. The hot carcass yield was higher in T3 than in the other treatments. The meat pH at slaughter and 24 hours postmortem was higher in T4 than in T1 and the meat protein percentage was higher in T3 than in T1. The inclusion of CTs from Acacia mearnsii extract in the diet of fattening lambs increased their daily weight gain, yield, and carcass weight.

SUMMARY: Currently, the most prevalent indication in order to close a patent foramen ovale is cryptogenic stroke. However, in the military environment, several special circumstances (tactical, medical and legal) may generate the need for a treatment outside the cryptogenic stroke context. We present a case of a patent foramen ovale closure in a military member.

RESUMEN: Actualmente, la indicación más prevalente para el cierre de un foramen ovale permeable (FOP) es el ictus criptogénico. Sin embargo, en el ámbito militar coexisten varias circunstancias especiales (tácticas, médicas y periciales) que pueden generar la necesidad de un tratamiento del FOP, fuera del contexto de un ictus criptogénico. Presentamos el caso de un cierre de FOP en un paciente militar.

ABSTRACT The objective of this research was the design and validation of a scale that would allow the analysis of the values acquired with the Model of Personal and Social Responsibility in schoolchildren, in comparison with the methodology previously taught by the teacher (ECVA-12) from the different subjects of the school curriculum. The cross-sectional and descriptive study was carried out in several phases and with different samples: with a sample of 104 students between 9 and 15 years old, content validity using the Delphi technique with 11 expert judges, comprehension validity, analysis of the temporal stability and construct validity through Exploratory Factor Analysis. Subsequently, and in this case with a sample of 76 students between 12 and 15 years old, a Confirmatory Factor Analysis was performed, showing adequate adjustment values in a 2-factor and 12-item model, with saturations and high internal consistency indices both in scale as in the subscales. The results obtained confirm that the designed instrument meets the established validity and reliability criteria, capable of measuring the degree of satisfaction and the perceived changes in the behavior of students, making it a basic tool for research related to the application of this teaching model.

RESUMO O objetivo desta pesquisa foi o desenho e validação de uma escala que permitisse a análise dos valores adquiridos com o Modelo de Responsabilidade Pessoal e Social em escolares, em comparação com a metodologia previamente ensinada pelo professor (ECVA-12) das diferentes disciplinas do currículo escolar. O estudo transversal e descritivo foi realizado em várias fases e com amostras distintas: com amostra de 104 alunos entre 9 e 15 anos, validade de conteúdo pela técnica Delphi com 11 juízes especialistas, validade de compreensão, análise de estabilidade temporal e validade de construto por meio da Análise Fatorial Exploratória. Posteriormente, e neste caso com uma amostra de 76 alunos entre 12 e 15 anos, foi realizada uma Análise Fatorial Confirmatória, mostrando valores de ajuste adequados em um modelo de 2 fatores e 12 itens, com saturações e altos índices de consistência interna ambos em escala como nas subescalas. Os resultados obtidos confirmam que o instrumento elaborado atende aos critérios de validade e confiabilidade estabelecidos, capazes de medir o grau de satisfação e as mudanças percebidas no comportamento dos alunos, tornando-se uma ferramenta básica para pesquisas relacionadas à aplicação deste modelo.

RESUMEN El objetivo de la presente investigación fue el diseño y la validación de una escala que permitiera analizar los valores adquiridos con el Modelo de Responsabilidad Personal y Social en escolares, en comparación con la metodología impartida previamente por el docente (ECVA-12) desde las diferentes materias del currículum escolar. El estudio de carácter transversal y descriptivo se llevó a cabo en varias fases y con muestras diferentes: con una muestra de 104 estudiantes entre 9 y 15 años, validez de contenido mediante la técnica Delphi con 11 jueces expertos, validez de comprensión, análisis de la estabilidad temporal y validez de constructo mediante Análisis Factorial Exploratorio. Posteriormente, y en este caso con una muestra de 76 estudiantes de entre 12 y 15 años, se realizó un Análisis Factorial Confirmatorio, mostrando valores de ajuste adecuados en un modelo de 2 factores y 12 ítems, con saturaciones e índices de consistencia interna elevados tanto en escala como en las sub-escalas. Los resultados obtenidos confirman que el instrumento diseñado cumple con los criterios de validez y fiabilidad establecidos, capaz de medir el grado de satisfacción y los cambios percibidos en el comportamiento de los estudiantes, convirtiéndolo en una herramienta básica para investigaciones relacionadas con la aplicación de este modelo de enseñanza.

ABSTRACT A report of a female patient with multinodular goiter, on whom a total thyroidectomy under intra-operative nerve monitoring was performed, finding a left non-recurrent laryngeal nerve and confirmed with the use of the monitoring device. Different from the few cases reported, no vascular anomaly was found.

RESUMEN Se describe el caso de una mujer con bocio multinodular en quien se practicó tiroidectomía total con monitoreo de nervio intraoperatorio, en quien se observó un nervio laríngeo no recurrente izquierdo confirmado por el dispositivo de monitoreo. Diferente a los pocos casos reportados no se encontró ninguna alteración vascular en la paciente.

Abstract: Lung auscultation is an essential part of the physical examination for diagnosing respiratory diseases. The terminology standardization for lung sounds, in addition to advances in their analysis through new technologies, have improved the use of this technique. However, traditional auscultation has been questioned due to the limited concordance among health professionals. Despite the revolu tionary use of new diagnostic tools of imaging and lung function tests allowing diagnostic accuracy in respiratory diseases, no technology can replace lung auscultation to guide the diagnostic process. Lung auscultation allows identifying those patients who may benefit from a specific test. Moreover, this technique can be performed many times to make clinical decisions, and often with no need for- complicated and sometimes unavailable tests. This review describes the current state-of-the-art of lung auscultation and its efficacy based on the current respiratory sound terminology. In addition, it describes the main evidence on respiratory sound concordance studies among health professionals and its objective analysis through new technology.

Resumen: La auscultación pulmonar es parte fundamental del examen físico para el diagnóstico de las enfermedades respiratorias. La estandarización que ha alcanzado la nomenclatura de los ruidos respiratorios, sumado a los avances en el análisis computacional de los mismos, han permitido mejorar la utilidad de esta técnica. Sin embargo, el rendimiento de la auscultación pulmonar ha sido cuestionado por tener una concordancia variable entre profesionales de la salud. Aun cuando la incorporación de nuevas herramientas diagnósticas de imágenes y función pulmonar han revolucionado la precisión diagnóstica en enfermedades respiratorias, no existe tecnología que permita reemplazar la técnica de auscultación pulmonar para guiar el proceso diagnóstico. Por una parte, la auscultación pulmonar permite seleccionar a aquellos pacientes que se beneficiarán de una determinada técnica diagnóstica, se puede repetir cuantas veces sea necesario para tomar decisiones clínicas, y frecuentemente permite prescindir de exámenes adicionales que no siempre son fáciles de realizar o no se encuentran dispo nibles. En esta revisión se presenta el estado actual de la técnica de auscultación pulmonar y su ren dimiento objetivo basado en la nomenclatura actual aceptada para los ruidos respiratorios, además de resumir la evidencia principal de estudios de concordancia de auscultación pediátrica y su análisis objetivo a través de nueva tecnología computacional.

Abstract During the last years Phytophthora infestans sensu lato (Mont. De Bary) has caused epidemics in Colombia in Andean fruit crops such as Solanum quitoense and Solanum betaceum. Establishment of new or modified experimental procedures to study this pathogen is a mandatory subject for scientists. Twelve isolates of Phytophthora spp. obtained from six different Solanum hosts in Colombia were used to evaluate the effect of five different solid media for growth and ability to produce sporangia and liberate zoospores. Determination of the best media culture and optimal growth temperature were necessary to perform measurements and correlate the provenance of isolates with phenotypic traits. Modifications were made to use ingredients available in local markets on the following media: lime bean agar (LBA), Tree tomato or tree tomato agar (TA), carrot agar (AZ), Rye A modified agar and 32% non-clarified V8 agar. Cardinal temperature determination was performed at 10, 15, 20, and 25 °C. Morphometric traits were measured once the optimal media culture and temperature were defined. Correlation analysis showed that there is a relationship between the host and isolate’s preferences for media culture and optimal growth temperature. In addition, the production of characteristic sporangia, sporangiophore and mycelia was related with the media type used and host from which the isolate was collected. In this work useful information was provided to make studies about the biology and development of isolates gathered from cultivated and wild non-traditional hosts.

Resumo Durante os últimos anos Phytophthora infestans sensu lato causou epidemias na Colômbia em lavouras de frutos andinos, como Solanum quitoense e Solanum betaceum. Estabelecimento de procedimentos experimentais novos ou modificados para estudar este patógeno é um assunto obrigatório para os cientistas. Doze isolados de Phytophthora spp. obtidos de seis diferentes hosts Solanum na Colômbia foram usados para avaliar o efeito de cinco diferentes mídias sólidas para o crescimento e a capacidade de produzir esporângios e libertar zoósporos. Determinação da melhor cultura de mídia e temperatura de crescimento ideal foram necessárias para realizar medições e correlacionar a proveniência de isolados com traços fenotípica. Foram feitas modificações para usar os ingredientes disponíveis nos mercados locais nos seguintes meios: ágar do feijão de cal (LBA), tomate da árvore ou ágar do tomate da árvore (TA), ágar da cenoura (AZ), centeio um ágar modificado e 32% de ágar-V8 não-esclarecido. A determinação da temperatura Cardeal foi realizada em 10, 15, 20 e 25 °C. Traços morfométricos foram medidos uma vez que a cultura de mídia ideal e temperatura foram definidos. Análise de correlação mostrou que há uma relação entre o hospedeiro e isolar as preferências para a cultura de mídia e temperatura de crescimento ideal. Além disso, a produção de esporângios característica, esporangióforo e mycelia foi relacionada com o tipo de mídia utilizado e hospedeiros a partir do qual o isolado foi coletado. Neste trabalho foram fornecidas informações úteis para fazer estudos sobre a biologia e o desenvolvimento de isolados recolhidos de hospedeiros não-tradicionais cultivados e selvagens.

Abstract Lab tests generate a large amount of waste, including Ag, Hg and Cr, which are the heavy metals from the determination of the Chemical Oxygen Demand (COD). The liquid waste generated by this parameter shows a high initial concentration of 1133 mg/L of Ag, 2252 mg/L of Hg and 950 mg/L of Cr, exceeding what the Official Mexican Standard NOM-002-SEMARNAT-1996 establishes. In this paper, a physicochemical procedure was optimized and applied to reduce the concentration of the heavy metals through laboratory experiments and the evaluation of the operating conditions (temperature, contact time and reagent concentration) using a factorial design 23. The results of the developed technique showed a satisfactory performance obtaining removal efficiencies of 99.99 % for Ag, 99.99 % for Hg and 99.96 % for Cr; the final concentration (0.1 mg/L for Ag, 0.001 mg/L for Hg and 0.36 mg/L for Cr) is below the limits of the Mexican standard. Due to the high removal efficiencies, this technique is adequate and simple to reduce the metals of the COD waste.

Resumen Las pruebas de laboratorio generan una gran cantidad de residuos, entre los que destacan Ag, Hg y Cr, que son los metales pesados provenientes de la determinación de la Demanda Química de Oxígeno (DQO). Los residuos generados por este parámetro muestran una concentración inicial de 1133 mg/L de Ag, 2252 mg/L de Hg y 950 mg/L de Cr, excediendo lo que establece la Norma Oficial Mexicana NOM-002-SEMARNAT-1996. En este trabajo, se optimizó y aplicó un procedimiento físico-químico para reducir la concentración de los metales mediante corridas experimentales y la evaluación de las condiciones de operación (temperatura, tiempo de contacto, concentración de reactante) empleando un diseño factorial 23. Los resultados de la técnica desarrollada mostraron un rendimiento satisfactorio al obtener eficiencias de remoción del 99.99 % para Ag, del 99.99 % para Hg y del 99.96 % para Cr, cuya concentración final (0.1 mg/L para Ag, 0.001 mg/L para Hg y 0.36 mg/L para Cr) está por debajo de los límites de la norma mexicana. Debido a los altos porcentajes de remoción mostrados, esta técnica resultó adecuada y simple para reducir los metales de los residuos de la DQO.

SUMMARY Bacterial wilt of tomato caused by Ralstonia solanacearum is a recurring problem in the state of Morelos and other parts of Mexico and the world. Current methods for the control of this bacterial phytopathogen are based on the use of antibiotics that promote the selection of resistant bacteria, and on agrochemicals that are toxic to humans, plants and the environment in general. These control methods degrade the quality of soils by eliminating much of the normal microbiota due to their broad spectrum of action. This situation highlights the need to develop alternative control methods that are aligned with the sustainable development of agriculture. The strict lytic bacteriophages offer an alternative of control due to their high specificity, low toxicity and capacity of auto-amplification. In this paper, the isolation, stability and inhibitory capacity of bacteriophage ФRSP, infective for R. solanacearum are reported. This bacteriophage belongs to the family Mioviridae and generates lysis plates of approximately 0.5 cm in diameter after 24 h of incubation, which continue to increase their size over time. This bacteriophage has the ability to clarify liquid cultures of R. solanacearum at very low multiplicities of infection and is stable in the nutrient solution used for the cultivation of hydroponic tomato, in a pH range from 4 to 11; however, it is unstable in ultrapure water. Results show that the bacteriophage ФRSP presents characteristics that point it as a good candidate to be used as a biocontrol agent against bacterial wilt caused by R. solanacearum.

RESUMEN La marchitez bacteriana del tomate causada por Ralstonia solanacearum es un problema recurrente en el estado de Morelos y otras partes de México y el mundo. Los métodos actuales para el control de este fitopatógeno bacteriano se basan en el uso de antibióticos que promueven la selección de bacterias resistentes y en agroquímicos que son tóxicos para los humanos, las plantas y el medio ambiente en general. Estos métodos de control degradan la calidad de los suelos al eliminar gran parte de la microbiota normal debido a su amplio espectro de acción. Esta situación pone de manifiesto la necesidad de desarrollar métodos de control alternativos que estén alineados con el desarrollo sostenible de la agricultura. Los bacteriófagos líticos ofrecen una alternativa de control debido a su alta especificidad, baja toxicidad y capacidad de auto-amplificación. En este trabajo se reporta el aislamiento, la estabilidad y la capacidad inhibitoria del bacteriófago ФRSP, infectivo para R. solanacearum. Este bacteriófago pertenece a la familia Mioviridae y genera placas de lisis de aproximadamente 0.5 cm de diámetro después de 24 h de incubación, que continúan aumentando su tamaño con el tiempo. Este bacteriófago tiene la capacidad de aclarar los cultivos líquidos de R. solanacearum a muy pocas multiplicidades de infección y es estable en la solución nutritiva utilizada para el cultivo de tomate hidropónico, en un rango de pH de 4 a 11; sin embargo, es inestable en agua ultrapura. Los resultados muestran que el bacteriófago ФRSP presenta características que lo señalan como un buen candidato para ser utilizado como agente de control biológico contra la marchitez bacteriana causada por R. solanacearum.

Abstract Samples of ‘Persian’ lime trees, from 5 to 8 years old, with symptoms of gummosis, cankers and dieback of branches were collected in orchards in the municipalities of Tlaltizapan, Ayala, Coatlan del Rio and Amayuca in the state of Morelos, Mexico, during August 2015. The samples were processed by routine procedures and sown in potato dextrose-agar and purified by means of hypha tips. The isolated pathogens were inoculated in healthy plants in order to evaluate their pathogenicity. Morphological and molecular identification was carried out and a Bayesian phylogenetic tree was constructed with clades grouping. Based on morphological characters, Lasiodiplodia sp. was identified. The molecular analysis allows to determine 16 isolates, which were grouped into 4 clades and three species, Lasiodiplodia citricola, L. pseudotheobromae and L. theobromae, which are considered as new reports, causing disease in ‘Persian’ lime for the State of Morelos, Mexico.

Resumen Muestras de árboles de lima ‘Persa’, de 5 a 8 años de edad, con síntomas de gomosis, canceres y muerte descendente de ramas fueron colectadas en huertos de los municipios de Tlaltizapán, Ayala, Coatlán del Río y Amayuca en el estado de Morelos, México, durante agosto del 2015. Las muestras fueron procesadas mediante procedimientos de rutina, sembradas en papa-dextrosa-agar y purificadas mediante puntas de hifa. Los patógenos aislados fueron inoculados en plantas sanas para evaluar su patogenicidad. Se realizó la identificación morfológica y molecular y se construyó un árbol filogenético bayesiano con agrupamiento de clados. Con base a caracteres morfológicos se identificó a Lasiodiplodia sp. El análisis molecular determinó 16 aislados, que se agruparon en 4 clados y tres especies, Lasiodiplodia citricola, L. pseudotheobromae y L. theobromae, las cuales son consideradas como nuevos reportes causando enfermedad en lima ‘Persa’ para el Estado de Morelos, México.

Abstract Ataulfo mango (Mangifera Indica L.) is one of the tropical fruits with highest demand due to its nutritional composition and characteristic flavor. However, losses of processed products, due to the presence of bacteria such as Escherichia coli O157:H7, are usually large. E. coli has been considered one of the 10 major pathogens concerned in foods. The use of high hydrostatic pressure technology in the processing of mango nectar would enable to obtain a safety product. The pathogen Escherichia coli O157:H7 was inoculated at 1x106 CFU/mL in mango nectar. The inoculated samples were then subjected to high hydrostatic pressure (150, 200 and 250 MPa) for 0, 10 and 20 min at 25, 35 and 45 °C. E. coli showed more resistance to high hydrostatic pressure at 25 °C than at 35 or 45 °C. Complete E. coli inactivation was observed at 150 MPa, 35 y 45 °C on day zero (day of treatment) and at 200 MPa, 35 °C on day zero and after 6 days of storage. Identification and quantification of chemical species by solid phase microextraction (SPME) of aromatic profiles of untreated and pressurized mango nectar was carried out. It was observed a reduction with the application of temperature in both, ethanol and α-Pimene concentration, in counterpart β-myrcene and 3-carene were not affected. The pH and total soluble solids showed no significant difference (p<0.05) with the pressure treatments. The treatment by high pressures allowed the complete inactivation of Escherichia coli O157: H7 without causing a negative effect on the aromatic profile of mango nectar.

Resumen El mango Ataulfo (Mangifera Indica L.) es una de las frutas tropicales con mayor demanda debido a su composición nutricional y característico sabor. Sin embargo, existen elevadas pérdidas de productos procesados, debido a la presencia de bacterias como Escherichia coli O157:H7, considerada una de los 10 patógenos de interés mundial presente en los alimentos. El uso de la tecnología de altas presiones hidrostáticas en el procesamiento del néctar de mango permitiría obtener un producto con mayor inocuidad. El patógeno Escherichia coli O157:H7 se inoculó en néctar de mango a una concentración de 1x106 CFU/mL. Las muestras inoculadas se sometieron a la alta presión hidrostática (150, 200 y 250 MPa) por 0, 10 y 20 min, a 25, 35 y 45 °C. E. coli mostró una mayor resistencia a la alta presión a 25 °C en comparación con 35 y 45 °C. La completa inactivación de la bacteria, se observó en las muestras tratadas a 150 MPa con 35 y 45 °C en el día cero (día del tratamiento) y a 200 MPa y 35 °C en el día cero y los siguientes 6 días de almacenamiento. La identificación y cuantificación del perfil aromático se determinó por microextración en fase sólida (SPME). Se observó una disminución en la concentración de etanol y α-pimeno al aplicar mayor temperatura. Con respecto a β-mirceno y 3-careno no hay diferencia significativa respecto al jugo fresco. El pH y los sólidos solubles no presentaron cambios significativos (p<0.05) al aplicarse los tratamientos de alta presión hidrostática. El tratamiento por altas presiones permitió la inactivación completa de Escherichia coli O157:H7 sin causar un efecto negativo sobre el perfil aromático del nectar de mango.

Abstract The Crassulaceae family is the most representative of Mexico due to the high endemism of most of its species and to its historical-cultural significance. They are prized and valued on the international market, causing an intense and illegal harvest and sacking of plants, fruits and seeds, with the purpose of selling and recording them in other countries. Morphological characteristics are used to study genetic diversity, to identify cultivated plants and the method of molecular characterization measures genetic variability and diversity with the purpose of conservation and protection of genetic resources. On that basis, the objective of this research work was the morphological and molecular characterization by RAPD (Random Amplified Polymorphic DNA) of twelve species of the Crassulaceae family. Twelve species of the family Crassulaceae were studied: Echeveria runyonii, E. perle, E. agavoides, E. pumila var. glauca x E. Walther., E. elegans, E. pulvinata, E. derembergii, E. setosa, Pachyphytum oviferum, Sedum clavatum, S. nussbaumerianum, and S. palmeri, which are endemic species. For morphological characterization, some characteristics used for plant description of some species from the Crassulaceae family were employed. Molecular characterization was performed by RAPD. Data were processed using the Numerical Taxonomic and Multivariate Analysis System (NTSYSpc 2.1). Quantitative characters separated the twelve species into five groups according to the cluster analysis. Six groups were obtained with the RAPD analysis. The most genetically similar species were: E. runyonii and E. derembergii, indicating more genetic crossing possibilities for interspecific hybridization.

Resumen La familia Crassulaceae es la más representativa de México debido al alto endemismo de la mayoría de sus especies y por su significado histórico-cultural; son cotizadas y valoradas en el mercado internacional, esto ha provocado una intensa recolecta y saqueo de plantas, frutos y semillas de manera ilegal, con fines de venta y registro en otros países. Las características morfológicas se utilizan para estudiar la diversidad genética, identificar plantas cultivadas y el método de la caracterización molecular mide la variabilidad genética y la diversidad genética con la finalidad de conservar y proteger los recursos genéticos. Con base en lo anterior, el objetivo de la investigación fue la caracterización morfológica y molecular mediante RAPD (Amplificación Aleatoria de DNA Polimórfico) de doce especies de la familia Crassulaceae. Se estudiaron doce especies de la familia Crassulaceae, Echeveria runyonii, E. perle, E. agavoides, E. pumila var. glauca x E. Walther., E. elegans, E. pulvinata, E. derembergii, E. setosa, Pachyphytum oviferum, Sedum clavatum, S. nussbaumerianum, y S. palmeri, las cuales son especies endémicas. Para la caracterización morfológica se usaron algunas características utilizadas para la descripción de plantas de algunas especies de la familia Crassulaceae. Se realizó la caracterización molecular mediante RAPD. Los datos se procesaron utilizando el Sistema de Análisis Multivariado y Taxonómico Numérico (NTSYSpc 2.1). Los caracteres cuantitativos separaron a las doce especies en cinco grupos según el análisis de conglomerados. Se obtuvieron seis grupos con el análisis RAPDs. Las especies con mayor similitud genética fueron: E. runyonii y E. derembergii, lo que indica mayor posibilidad genética de cruzamiento para hibridación interespecífica.

ABSTRACT Nowadays, it is not possible to train a healthcare professional only based on theoretical knowledge, but acquiring the highest surgical skills to avoid unnecessary risks in a highly demanding society, therefore dissection and training of surgical procedures play a key role in fulfilling this objective, which is why a form of cadaveric preservation has recently been promoted, which allows realizing such training through realistic situations. An electronic literature search was carried out, restricted to the English language in MEDLINE, where it is intended to describe and analyze the applications of this technique. The review offered articles of relevance that demonstrate the application of this novel technique in the preservation of corpses and their possible applications in the field of otorhinolaryngology.

RESUMEN Los tiempos modernos nos obligan a que la formación de un médico cirujano no se base sólo en conocimientos teóricos, sino que adquiera las mayores habilidades quirúrgicas para así evitar riesgos innecesarios en una sociedad altamente exigente. La disección y el entrenamiento de los procedimientos quirúrgicos juegan un papel primordial para cumplir este objetivo, por lo que recientemente se ha promovido una forma de preservación cadavérica que permite realizar mediante situaciones bastantes realistas dichos adiestramientos. Se realizó una búsqueda bibliográfica electrónica, restringida al idioma inglés en Pubmed, Scopus y WOS donde se pretende describir y analizar las aplicaciones de esta técnica. La revisión ofreció artículos de relevancia que demuestran la aplicación de esta técnica novedosa en la preservación de cadáveres y sus posibles aplicaciones en el campo de otorrinolaringología.