Resumen Los carotenoides son compuestos no polares que se encuentran en frutas y hortalizas. El consumo de estos compuestos se ha asociado con muchos efectos benéficos para la salud humana, especialmente en la prevención de enfermedades crónicas que actualmente se consideran problemas de salud pública. Estos efectos se han atribuido principalmente a las propiedades antioxidantes de los carotenoides, aunque muchos otros mecanismos están involucrados en estos efectos, incluida la influencia de los carotenoides en la expresión de genes implicados en la patogénesis de estas enfermedades. Desafortunadamente, la biodisponibilidad de estos compuestos es muy limitada, razón por la cual se han estudiado los efectos de varios factores en la biodisponibilidad de los carotenoides con el fin de identificar las mejores estrategias para aumentar la absorción de estos compuestos y, en consecuencia, su bioactividad. En esta revisión se analizan de manera sistemática los descubrimientos recientes sobre la composición de carotenoides en alimentos de origen vegetal y su biodisponibilidad y efectos protectores de la salud humana.

Abstract Carotenoids are non-polar compounds found in fruits and vegetables. The consumption of these compounds has been associated with many beneficial effects on human health, especially on the prevention of chronic diseases that are currently considered as problems of public health. These effects have mainly been attributed to the antioxidant properties of carotenoids, although many other mechanisms are involved, including the influence of carotenoids in the expression of genes involved in the pathogenesis of these diseases. Unfortunately, the bioavailability of these compounds is very limited. The effects of several factors on carotenoid bioavailability have been studied in order to identify the best strategies to increase their absorption and, consequently, their bioactivity. This review analyzes in a systematic fashion the recent findings on the composition of carotenoids composition in plant foods, and their bioavailability and beneficial effects on human health.

Abstract Mexico is a megadiverse region with a complex geological history, but it remains unclear to what extent the distribution of freshwater fish has been influenced by geographic barriers. This study examines the population level genetic divergence and phylogenetic relationships of species in the shortfin group of the subgenus Mollienesia (genus Poecilia), a group of live-bearing fishes that are widely distributed across Mexico, with sampling at a small geographic scale. Samples from over 50 locations were analyzed for six species by using phylogenetic and haplotype network approaches to assess genetic diversity across geographic ranges and to refine the distributions of species in this group. The results indicate that Mexican species have diversified following multiple, independent invasions from Middle America. Two species found north of the Trans-Mexican Volcanic Belt (TMVB) and one transversal species exhibited weak phylogenetic structure, likely due to the lack of physiographic barriers, recent colonization, and high dispersal rates among regions. In contrast, three species found south of the TMVB exhibited strong phylogenetic structure, reflecting a longer presence in the area and multiple physiographic barriers that isolated populations. This study identified mechanisms driving divergence and speciation, expanded the known range of several species, and resolved taxonomic uncertainties of populations.

Resumen México es una región megadiversa con una historia geológica compleja, pero se desconoce el nivel de influencia de las barreras geográficas sobre las distribuciones de los peces dulceacuícolas. Este estudio examina las relaciones filogenéticas, a escala geográfica pequeña, de las especies del grupo de aletas cortas del subgénero Mollienesia (género Poecilia), un grupo de peces vivíparos ampliamente distribuidos en México. Se analizaron muestras de seis especies en más de 50 localidades, utilizando métodos filogenéticos y de redes de haplotipos, para evaluar la diversidad genética y precisar las distribuciones de especies en este grupo. Los resultados indican que las especies mexicanas se han diversificado a partir de múltiples invasiones independientes desde Mesoamérica. Se detectó estructura filogenética débil en dos especies distribuidas al norte del Eje Neovolcánico y una especie que atraviesa el Eje Neovolcánico, posiblemente debido a la ausencia de barreras fisiográficas, colonización reciente y altas tasas de dispersión entre regiones. En contraste, se detectaron niveles altos de estructura filogenética en tres especies distribuidas del Eje Neovolcánico, lo que refleja una presencia más prolongada en el área y la existencia de múltiples barreras fisiográficas que aislaron a las poblaciones. Este estudio identificó mecanismos que promueven la divergencia y la especiación, expandió el rango conocido de varias especies y resolvió incertidumbres taxonómicas de algunas poblaciones.

Resumen La sistemática del género Vieja es compleja, incluye especies morfológicamente similares con poca diferenciación genética. La revisión de características morfológicas puede ser útil para clarificar su taxonomía. Se analizó la variación morfológica de los huesos de las mandíbulas oral y faríngea inferior para determinar si estas estructuras ayudan a delimitar a las especies y evaluar posibles implicaciones funcionales. Las diferencias morfológicas se cuantificaron con un análisis de variables canónicas, Manova y comparaciones pareadas. Se comparó el número de dientes faríngeos en la mandíbula faríngea inferior con un Ancova. La forma de la premaxila y la mandíbula faríngea inferior mostró ser útil para delimitar estas especies. Aunque la variación morfológica entre V. breidohri y V. hartwegi fue poca, la forma de la mandíbula faríngea inferior difiere en el morfoespacio. Vieja bifasciata es la especie que posee más dientes en la mandíbula faríngea inferior. La variación en estos huesos puede afectar la biomecánica de la mandíbula e influir en la conducta alimentaria. Las diferencias morfológicas contrastan con la escasa diferenciación genética observada. El aislamiento geográfico de V. bifasciata probablemente esté relacionado con su diferenciación morfológica. Las relaciones filogenéticas entre V. breidohri y V. hartwegi podrían explicar su baja divergencia morfológica.

Abstract The systematics of the genus Vieja is complex because it contains many morphologically similar species that have little genetic differentiation. Examination of morphological traits can be useful for clarifying their taxonomic status. We analyzed the morphological variation of bones in the oral and lower pharyngeal jaws to determine whether these structures permit the differentiation of species and to study possible functional implications. Morphological differences were quantified using canonical variates analysis, MANOVA, and paired comparisons. Differences in the number of pharyngeal teeth in the lower pharyngeal jaw were determined using an ANCOVA. The shape of the premaxilla and lower pharyngeal jaw proved useful for the delimitation of these species. Although the morphological variation between V. breidohri and V. hartwegi is minimal, the shapes of their lower pharyngeal jaws differ in morphospace. Vieja bifasciata possesses more teeth in the lower pharyngeal jaw when compared to the other species. Variation in these bones may affect jaw biomechanics and influence feeding behavior. However, these morphological differences contradict the weak genetic differentiation observed. The geographic isolation of V. bifasciata is likely related to its morphological differentiation. The close phylogenetic relationship between V. breidohri and V. hartwegi likely explains their low morphological divergence.

ABSTRACT The variability in fruit pungency, size and quality was analyzed in 31 landraces of piquín pepper (Capsicum annuum L. var. glabriusculum (Dunal) Heiser & Pickersgill) collected from 10 Mexican states. The response of fruits collected in situ and harvested in greenhouse was compared. Pungency was estimated by measuring capsaicinoids content with HPLC. Additionally, pungency was recorded along fruit maturity stages in greenhouse-grown fruits. On average, greenhouse- produced fruits were markedly more pungent than fruit collected from field locations (29 485 vs. 6114 SHU). Field- collected fruits averaged 5017 μg mL-1 capsaicin content, while dihydrocapsaicin averaged 7618 μg mL-1. In contrast, greenhouse-harvested fruits contained substantially more capsaicin and dihydrocapsaicin (34 762 and 26 174 μg mL-1, respectively), while the capsaicin:dihydrocapsaicin ratio inverted. The three most pungent field-collected landraces averaged 35% of the pungency measured in the three most pungent greenhouse-grown fruits. Pungency increased as maturity stage advanced: green (14 813 SHU) < intermediate (24 767 SHU) < red (29 485 SHU). The fruits collected from 31 field locations had lower titratable acidity, higher content of total soluble solids, and higher maturity index than fruits harvested in greenhouse. Greenhouse harvested fruits were larger and heavier than those collected in the field.

Abstract The entry of extreme right-wing populist formations into the institutions of Spain and Portugal represents a qualitative change in their political systems. One relevant issue is the electoral use of the strategy of punitive populism, a tool already used extensively by other more veteran formations within this ideological family in Europe. The question addressed in this text is to what extent they have used this strategy, and whether they have made any particular modulation of it in their electoral manifestos in force during the elections for entry into the parliamentary chambers of each of the Iberian countries.

Resumen La entrada de formaciones de extrema derecha populista en las instituciones de España y Portugal supone un cambio cualitativo de sus sistemas políticos. Una cuestión relevante es el uso electoralista de la estrategia del populismo punitivo, una herramienta ya utilizada de manera extensiva por otras formaciones más veteranas dentro de esa familia ideológica. La cuestión que aborda este texto es en qué grado han utilizado esta estrategia y si han realizado alguna modulación particular de la misma dentro de sus manifiestos electorales vigentes durante los comicios de entrada en las cámaras parlamentarias de cada uno de los países ibéricos.

ABSTRACT Blasting and drilling methods are mainly used in basalt rock quarries as blasting-digging methods. The purpose of this study is to argue the validity of using a jackhammer as a rock removal method in Gabricar quarry, based on knowing the geomechanical parameters of rocks as well as the technical-economic indicators for exploitation. Gravimetric, saturation, hydrostatic weighing, pycnometric and axial loads methods were used to obtain physical-mechanical properties of the rocks and geological survey, volumetric joint count, and strength coefficient were used to establish crack elements, block size, and rock mass quality, respectively. 4.75% humidity; 2.39 % porosity; 5.73 g/cm3 volumetric mass; density of 26.44 g/cm3 and axial compressive strength of 173.53 Mpa as average values of physical-mechanical properties were obtained. Four families of cracks with spacing of 0.4 m, 0.6 m; 0.3 m and 0.2 m and 18 mm openings; 13 mm; 3 mm and 9 mm, respectively were established. Blocks are small and the rocky massif is of good quality. The technical-economic analysis showed the efficiency of the jackhammer as a blasting-based digging method in Gabricar quarry.

RESUMEN En las canteras de rocas basálticas se emplean fundamentalmente métodos de perforación y voladura como métodos de arranque. El objetivo de este estudio fue argumentar la validez del uso de martillo rompedor como método de arranque de rocas en la cantera Gabricar, a partir de conocer los parámetros geomecánicos de las rocas así como los indicadores técnico-económicos de explotación. Las propiedades físico-mecánicas de las rocas se obtuvieron mediante los métodos: gravimétrico, de saturación, pesada hidrostática, picnométrico y cargas axiales, y para establecer elementos de las grietas, tamaño de bloques y calidad del macizo rocoso, se emplearon, respectivamente, el levantamiento geológico, recuento de las juntas volumétricas y coeficiente de fortaleza. Se obtuvieron como valores promedios de las propiedades físico-mecánicas, un 4,75 % de humedad; 2,39 % de porosidad; 5,73 g/cm3 de masa volumétrica; densidad de 26,44 g/cm3 y resistencia a comprensión axial de 173,53 Mpa. Se establecieron cuatro familias de grietas con espaciamientos de 0,4 m; 0,6 m; 0,3 m y 0,2 m y aberturas de 18 mm; 13 mm; 3 mm y 9 mm, respectivamente. Los bloques son de pequeño tamaño y el macizo rocoso califica como de buena calidad. El análisis técnico-económico demostró la eficiencia del martillo rompedor como método de arranque en la cantera Gabricar.

Resumen Calculamos los estados electrónicos en volumen para GaAs y AlAs en estructura Zinc-Blenda usando el método Tight-Binding (TB). El Hamiltoniano TB se construyó usando una base de orbitales s, p y s*. Los orbitales s* representan estados excitados con igual simetría de los orbitales s. Llevando a cabo la diagonalización numérica del Hamiltoniano, se determinaron las relaciones de dispersión para algunas direcciones de alta simetría de la primera zona de Brillouin (PZB), obteniendo un gap directo de 1.54 eV para GaAs y un gap indirecto de 2.26 eV para AlAs. Las densidades de estados totales (DOS) y parciales indican la presencia de orbitales s en la parte inferior de la banda de valencia (BV), orbitales p en la parte superior de la BV y en la parte inferior de la banda de conducción (BC), y orbitales s* en la parte superior de la BC. Nuestros resultados concuerdan bastante bien con otros reportes experimentales y teóricos.

Abstract We calculate the electronic states in volume for GaAs and AlAs in Zinc-Blenda structure using the Tight-Binding (TB) method. The TB Hamiltonian was constructed using a base of s, p and s* orbitals. The s* orbitals represent excited states with equal symmetry as the s orbitals. Carrying out the numerical diagonalization of the Hamiltonian, the dispersion relationships were determined for some directions of high symmetry of the first Brillouin zone (FBZ), obtaining a direct gap of 1.54 eV for GaAs and an indirect gap of 2.26 eV for AlAs. The total (DOS) and partial state densities indicate the presence of s orbitals in the lower part of the valence band (BV), p orbitals in the upper part of the BV and in the lower part of the conduction band (BC), and s* orbitals on top of BC. Our results agree quite well with other experimental and theoretical reports.

Abstract The tropical genus Heteromys includes 17 species that have undergone several taxonomic changes and have unclear interspecific limits. We compared the intraspecific, interspecific, and geographic variation in ten species of Heteromys using geometric morphometrics, and evaluated whether the genetic differences between the species were reflected in differences in cranial morphology. We digitized three cranial views and one mandibular view of 638 adult specimens, and performed morphometric analyses. Sexual variation and differences in cranial morphology were evaluated with analysis of variance, multivariate analysis of variance, and canonical variate analysis. Cranial differences were observed with deformation grids, and a cluster analysis was performed with Procrustes distances to compare with a phylogenetic tree. The geographic variation analyses were carried out using clusters based on physiographic regions. Only H. desmarestianus and H. irroratus presented sexual variation. Heteromys species showed differences between physiographic regions probably due to variation in abiotic factors, vegetation cover, and precipitation. Each species had a distinctive morphotype, with differences in their rostri, zygomatic arches, cranial vaults, occipitals, and foramina magna, as well as in the angular processes, condylar processes, and diastemas of the mandibles. The species clusters matched with clades previously identified by molecular markers. The specimens of one candidate species (Heteromys sp.) showed unique morphometric characteristics that separated them from the other species.

Abstract The canids gray fox Urocyon cinereoargenteus and coyote Canis latrans consume the fruits of Mexican fan palm, Washingtonia robusta, endemic to the oases of the Sonoran Desert. We analyzed biotic covariates (consumption, dispersal, and germination of palm seeds and abundance of gray foxes and coyotes) and organic matter in soils between different exposures in Barajitas Canyon, to better understand palm establishment. Mexican fan palm seeds found in feces had a greater germination rate (94%) than those dispersed directly from mother plants (55%). According to the results for palm establishment, the habitat can provide likely locations for successful colonization that did not significantly differ among sampling sites (α = 0.05, F = 1.104). The canyon is a dynamic habitat in which the reproductive season of these 2 mammals coincides with palm reproductive phenology. Our data suggest that the consumption and dispersal of W. robusta seeds by gray fox and coyote represent a positive interaction that plays a significant role in the establishment of this oasis species.

Resumen Los cánidos zorra gris Urocyon cinereoargenteus y coyote Canis latrans consumen los frutos de la palma de abanico mexicana Washingtonia robusta, endémica de los oasis del desierto sonorense. Analizamos covariables bióticas (consumo, dispersión, germinación de las semillas de la palma y abundancia de zorra gris y coyote) y el contenido de materia orgánica de los suelos entre diferentes condiciones de su exposición de dosel en el cañón de Las Barajitas, para entender mejor el establecimiento de las palmas. Las semillas de la palmera de abanico mexicana encontradas en las heces tuvieron una mayor tasa de germinación (94%) que las semillas de las palmas (55%). De acuerdo con los resultados para el establecimiento de palmas, el hábitat puede proporcionar sitios adecuados para una colonización exitosa, sin diferencias significativas entre los sitios de muestreo ((α = 0.05, F = 1.104). Este cañón es un hábitat dinámico en el que la temporada reproductiva de estos 2 mamíferos coincide con la fenología reproductiva de la palma. Nuestros datos sugieren que el consumo y la dispersión de las semillas de W. robusta por la zorra gris y el coyote representan una interacción positiva que juega un papel importante en el establecimiento de esta especie en los oasis.

RESUMO A relação alométrica entre peso corporal (PC) e frequência cardíaca (FC) foi descrita como inversamente proporcional em animais domésticos, mas isso tem sido refutado. A relação entre FC e variáveis eletrocardiográficas é descrita na literatura. No entanto, estudos sobre a variação e a influência de fatores nos parâmetros hemodinâmicos e eletrocardiográficos em cães não são abundantes. A taxa metabólica é definida como a produção e dissipação de calor pela área de superfície corporal (ASC), de modo que é essencial definir essa relação. Foi realizado um estudo retrospectivo para analisar a correlação entre FC, parâmetros eletrocardiográficos (ECG) e peso corporal em cães. Foram analisados mil traçados eletrocardiográficos, além dos parâmetros de ECG e dados clínicos, como gênero, idade e peso corporal. A determinação da ASC foi realizada da seguinte forma: ASC (m 2 ) = (10,1x peso corporal 0,67 ) x 10 -4 . Quando os grupos unificados foram analisados, houve uma correlação negativa, porém fraca (r= -0,14, P<0,0001) entre PC e FC. Houve diferenças entre os grupos de peso em relação às variáveis eletrocardiográficas. Não há relação alométrica entre PC e FC em cães. O peso foi associado a alterações nas variáveis de ECG.

ABSTRACT The allometric relationship between bodyweight (BW) and heart rate (HR) has been described as inversely proportional in domestic species, but that has been refuted. The relationship between HR and electrocardiographic variables is described in literature. However, studies about the variation and influence of factors on the hemodynamic and electrocardiographic parameters in dogs are not abundant. As the metabolic rate is defined as the production and dissipation of heat by the body surface area (BSA) in m², it is essential to define that relationship. A retrospective study was conducted to analyze the correlation between HR, ECG parameters and BW in dogs. One thousand electrocardiographic tracings were analyzed in addition to the ECG parameters and clinical data such as gender, age and bodyweight. The determination of BSA was performed as follows: BSA (m2) = (10.1 x bodyweight 0.67) X 10-4. When the unified groups were analyzed, there was a negative but weak correlation (r= -0.14, P< 0.0001) between bodyweight and HR. There were differences between weight groups regarding electrocardiographic variables. There is no allometric relationship between BW and HR in dogs. Weight was associated with changes in ECG variables.

RESUMO Este estudo teve como objetivo avaliar os efeitos dos níveis de eletrólitos, glicose e cortisol sobre a frequência cardíaca (FC) e a variabilidade da frequência cardíaca (VFC) em bezerros recém-nascidos e saudáveis. Dezessete bezerros da raça Holandesa foram avaliados durante o primeiro mês de vida e foram analisadas as concentrações plasmáticas de glicose, cortisol, cálcio, magnésio, fósforo inorgânico, sódio e potássio. Os índices VFC foram determinados em domínios de tempo e frequência por meio da análise de gravações do eletrocardiograma neonatal. No primeiro dia, baixos níveis sanguíneos de fósforo correlacionaram-se fortemente com FC e aumento dos componentes de alta frequência da VFC. As concentrações plasmáticas de magnésio diminuíram significativamente ao longo dos 35 dias, revelando correlação positiva com a diminuição dos componentes de baixa frequência da VFC no dia 28. Houve uma forte correlação entre FC, índices de VFC, eletrólitos plasmáticos, glicose e cortisol durante o período estudado. As variações nas concentrações e correlações observadas podem ser atribuídas ao período neonatal adaptativo em bezerros.

ABSTRACT This study aims at evaluating the effects of electrolytes, glucose and cortisol levels over heart rate (HR) and heart rate variability (HRV) in healthy newborn calves. Seventeen healthy Holstein calves were evaluated during their first month of life, and the plasma concentrations of glucose, cortisol, calcium, magnesium, inorganic phosphorus, sodium and potassium were analyzed. HRV indexes were determined in the time and frequency domains through the analysis of neonatal electrocardiogram recordings. In the first day, low blood levels of phosphorus presented a strong correlation with the HR and the increased high-frequency components of HRV. The plasma concentrations of magnesium decreased significantly throughout the 35 days, revealing a positive association with a decreasing low-frequency components of HRV at day 28. There was a strong correlation between HR, HRV indexes, some plasma electrolytes, glucose and cortisol during the studied period. Variations in the concentrations and correlations observed may be attributed to the adaptive neonatal period in calves.

Abstract: Background: Washingtonia robusta fruits are a staple for birds, small and medium-size mammals, and humans. However, quantitative data of their nutritional contribution has remained unknown. This is the first report on the phytochemical components found in fruit pulp and seeds. Questions: Does pulp compounds favor its consumption and contribute with nutrients for wildlife and humans? Do seed contents favor ecological interactions for germination and plantlet development? Species study: Washingtonia robusta H. Wendl. Study site and dates: Sierra El Aguaje, Sonora, Mexico, February - April 2016 Methods: Chemical and secondary metabolite analyses were carried out from extracts via phytochemical coloring tests and ultra-resolution liquid chromatography. Antioxidant activity was analyzed by DPPH. Results: Washingtonia robusta seeds contain 73 % sugars, 7.4 % protein, 8.4 % humidity, 4.3 % ashes, 8.7 % fat and 0.2 % calcium, while cyanogenic glycosides content was 0.8 μg/g. Pulp has 71 % sugars, 10.8 % protein, 1.6 % humidity, 5.5 % ashes, 9.4 % fat and 1.5 % calcium, and cyanogenic glycosides reached 0.2 μg/g. Alkaloids, tannins, saponins, phenols, and flavonoids were more abundant in seeds than in pulp. The DPPH assay expressed in Trolox equivalents indicated antioxidant capacity. Conclusions: Washingtonia robusta pulp is an important source of sugars and natural antioxidants for wildlife and human consumption. Occurrence of secondary metabolites prevents pathogens in seeds, also they could be beneficial for germination and initial plantlet development.

Resumen: Antecedentes: Los frutos de Washingtonia robusta son un alimento para aves, pequeños y medianos mamíferos y humanos. Sin embargo, se desconocen los datos cuantificados de su contribución nutricional. Este es el primer informe sobre sus componentes fitoquímicos en la pulpa de su fruta y semillas. Preguntas: ¿Los compuestos de la pulpa favorecen su consumo y contribuyen con nutrientes para la vida silvestre, así como para el consumo humano? ¿El contenido de las semillas favorece las interacciones ecológicas para la germinación y el desarrollo vegetal? Especie en estudio: Washingtonia robusta H. Wendl. Sitio de estudio y fechas: Sierra El Aguaje, Sonora, México, febrero-abril 2016 Métodos: Análisis químico proximal y de metabolitos secundarios a partir de extractos crudos, pruebas fitoquímicas de coloración y cromatografía líquida de ultra resolución; actividad antioxidante por DPPH. Resultados: La semilla contiene 73 % azúcares, 7.4 % proteína, 8.4 % humedad, 4.3 % cenizas, 8.7 % grasa, 0.2 % calcio y glucósidos cianogénicos 0.8 μg/g. Los componentes de la pulpa incluyen: 71 % azúcares, 10.8 % proteína, 1.6 % humedad, 5.5 % cenizas, 9.4 % grasa, 1.5 % calcio y 0.2 μg/g de glucósidos cianogénicos. Los alcaloides, taninos y saponinas son más abundantes en las semillas que en la pulpa, lo mismo ocurre con fenoles y flavonoides. El ensayo DPPH expresado en equivalentes Trolox indicó la capacidad antioxidante. Conclusiones: Los frutos de W. robusta son una fuente de azúcares y antioxidantes naturales para el consumo por la fauna y los humanos. Los metabolitos secundarios presentes en la semilla son disuasorios a patógenos, y pueden ser benéficos para la germinación y el desarrollo de la plántula.

RESUMO Apresenta-se uma análise crítica de uma técnica numérica que tem sido usada na resolução de equações diferenciais de ordem fracionária com derivadas de Caputo. Trata-se do método multi-passos com transformada diferencial generalizada. Verifica-se que a versão do método disponível na literatura produz soluções erradas a partir do segundo passo, isto é mostrado em aplicações aos modelos de Malthus e de Riccati. O problema é explicado em termos da não localidade da derivada de Caputo e das propriedades da transformada diferencial generalizada.

ABSTRACT This paper presents a critical analysis of a numerical technique that has been used in the resolution of fractional differential equations with Caputo derivative. It is the multi-step method with generalized differential transform. It is found that the version of the method available in the literature produces erroneous solutions from the second step, this is shown in applications to the Malthus and Riccati models. The procedure error is explained in terms of the nonlocality of the Caputo derivative and the properties of the generalized differential transform.

Abstract: We have identified a scarcely known river otter population from the Upper Río Conchos basin, northern Mexico, finding a well-established population of the Nearctic otter Lontra canadensis. A pioneer study of these otters at Río San Pedro, a tributary of the Río Conchos, described them as Neotropical otters, Lontra longicaudis; at that time, no specimens or photographs of these otters were available from the locality. Therefore, its taxonomic status remained unclear for various decades. Río Conchos is one of the major tributaries of Río Grande (Río Bravo in Mexico) and its headwaters are located high in the Sierra Madre Occidental. A juvenile otter fur obtained from Río San Pedro was compared to two furs of Neotropical otters from Oaxaca and Sonora, with the aim to compare the structure of primary hairs (PH) and secondary hairs (SH) in order to know their specific status. Camera traps were set-up at Río San Pedro in Chihuahua and in Arroyo Bamochi (occupied by L. longicaudis) in Sonora in 2015 to compare individuals, population structure and occupation in both places. Two other places were surveyed to confirm the presence of river otters: Río Conchos and Río Santa Isabel. Based on hair characteristics (primary and secondary hairs from the juvenile) and photographic evidence from camera-traps, we confirm that otters from Río San Pedro, belong to the Nearctic otter, Lontra canadensis. And presumably in other localities visited in the Concho’s river basin that also has presence of otters, such as Río Santa Isabel and Río Conchos. The population structure from Arroyo Bamochi and Río San Pedro were similar in both areas, but the density of otters is higher at Arroyo Bamochi than at Río San Pedro, even though there is no significant difference between the two sites. Specimens of river otters from Río Grande basin have been identified as L. canadensis lataxina, Cuvier, 1823. The former distribution area of this species ranges from inland US across the Río Grande basin in the Rocky Mountains, the Río Pecos, further East, flowing south and southeast into the Gulf of Mexico. The finding reported here represents a major area occupied by this species, and a significant conservation issue for their protection in Mexico, as well as an indicator of the healthy conservation status of the upper Río Conchos.

Resumen: Se identificó una población de nutria de río escasamente conocida de la cuenca alta del Río Conchos en el norte de México. Encontramos que la población está bien establecida y corresponde a la nutria Neártica, Lontra canadensis. Un estudio pionero de estas nutrias en el Río San Pedro, tributario del Río Conchos, las describió como nutria Neotropical, Lontra longicaudis; en ese tiempo no se conocía ningún espécimen o fotografías de nutrias de la localidad. Por lo que su estado taxonómico era poco claro, lo que duró varias décadas. El Río Conchos es uno de los mayores tributarios del Río Bravo (Río Grande en los Estados Unidos) y sus cabeceras se encuentran localizadas en la parte alta de la Sierra Madre Occidental. Se obtuvo la piel de una nutria juvenil del Río San Pedro, la cual fue comparada con dos pieles de nutria Neotropical, una de Oaxaca y otra de Sonora, para cotejar la estructura de los pelos primarios (PH) y de los pelos secundarios (SH) y determinar a qué especie pertenecía el individuo. Se colocaron cámaras trampa en el Río San Pedro en Chihuahua y en el Arroyo Bamochi (ocupado por L. longicaudis) en Sonora en el 2015, para comparar la estructura poblacional y la ocupación en ambos lugares. Otros dos lugares fueron visitados para confirmar la presencia de las nutrias, el: Río Conchos y el Río Santa Isabel. Con base en las características del pelo (pelos primarios y secundarios de la piel del juvenil) y evidencia fotográfica de las cámaras-trampa, confirmamos que las nutrias del Río San Pedro, Río Santa Isabel y del Río Conchos pertenecen a la especie Neártica: Lontra canadensis. La estructura de la población en el Arroyo Bamochi y en el Río San Pedro fueron similares en ambos sitios, pero la densidad de nutrias es más alta en el Arroyo Bamochi que en el Río San Pedro, aun así, no existe diferencia significativa entre los dos sitios. Los especímenes de nutrias de la Cuenca del Río Grande han sido identificados en el pasado como L. canadensis lataxina, Cuvier, 1823. La distribución original de esta especie va desde el interior de los Estados Unidos, a través de la Cuenca del Río Grande y del Río Pecos, de las montañas Rocallosas hacia el sur y sureste hacia el Golfo de México. El hallazgo reportado aquí representa un reto significativo para la conservación de esta especie en México, así como es un indicador del excelente estado de conservación del río.

Summary Hawthorn (Crataegus spp.) is a plant widely distributed in Mexico, where it is mainly used as food for humans and feed for livestock. Its use in traditional medicine is low, compared to that in other countries. Historically, the fruit has been used to treat many conditions, including cardiovascular diseases, which represent one of the leading causes of death in Mexico and the world. Scientific studies attribute some beneficial effects of hawthorn to phenolic compounds. In this review, the beneficial effects attributed to hawthorn and the mechanisms of action involved are analyzed in a critical and systematic way in order to promote its use in the treatment of various diseases considered in Mexico as public health problems.

Resumen El tejocote (Crataegus spp.) es una planta ampliamente distribuida en México, donde se le utiliza principalmente como alimento humano y para el ganado. Su uso en la medicina tradicional es bajo, comparado con el que se presenta en otros países. Históricamente, este fruto se ha utilizado para tratar un sinnúmero de padecimientos, que incluyen enfermedades cardiovasculares, las cuales representan una de las principales causas de muerte en México y el mundo. Los estudios científicos atribuyen algunos efectos benéficos del tejocote a los compuestos fenólicos. En la presente revisión, se analizan de manera crítica y sistemática los efectos benéficos atribuidos al tejocote y los mecanismos de acción involucrados, con la finalidad de promover su uso en el tratamiento de diversos padecimientos catalogados en México como problemas de salud pública.