ABSTRACT In order to provide information on the current knowledge about the native fish Dormitator latifrons and identify the gaps that must be filled to achieve correct resource management, a scientometric study was carried out using different scientific databases. A total of 103 publications were registered between the years 1972 and 2021. Results indicate that the species has been addressed since 2001 with less than one publication per year, with 2008 being the year with the highest number of publications (10). The main topics addressed were ecology, physiology, and parasitology of fish. The available knowledge generated about the species is concentrated in 68 journals, with Mexico as the most productive country, followed by USA and Ecuador, and the most productive research centers about this fish were Mexico’s Instituto Politécnico Nacional and Universidad de Guadalajara. A total of 285 authors were detected contributing knowledge to the species, with Violante-González in the top with ten publications. The co-authorship co-occurrence maps suggest there is no solid collaborative relationship between the scientific community and that the information generated is insufficient for conserving and exploiting this fish. It is essential to increase the study of thematic areas that allow their comprehensive management in the medium term; topics like reproduction in captivity, aquaculture, and nutrition must be addressed in the future to assure a sustainable use of this resource.

Resumen Introducción. Los estudios de conocimientos, actitudes y prácticas (CAP) relacionados con la Covid-19 permiten establecer los conceptos erróneos y las prácticas inadecuadas en torno a esta enfermedad, información fundamental para diseñar estrategias eficaces y mejorar el cumplimiento de las medidas de prevención. Objetivo. Establecer los conocimientos, actitudes y prácticas relacionadas con la Covid-19 en pacientes venezolanos cribados en la carpa de triaje del Hospital Universitario de Caracas. Materiales y métodos. Se hizo un estudio transversal en 215 pacientes entre el 25 de abril y el 25 de mayo de 2020, mediante entrevistas personales y utilizando una encuesta sobre conocimientos, actitudes y prácticas. Resultados. La mayoría (53,5 %) de los pacientes encuestados se encontraba asintomática; los encuestados tenían un conocimiento adecuado sobre los síntomas y la transmisión de la enfermedad, sin distinción entre sintomáticos y asintomáticos. La mayoría de ellos indicó estar respetando las prácticas de cuarentena, lavado de manos frecuente y uso de tapabocas en público; sin embargo, el reemplazo diario de los tapabocas de tela fue más frecuente en el grupo de los asintomáticos, en tanto que el reemplazo cada tres días fue más común entre los sintomáticos. Por último, más de la mitad de los participantes admitió haber estado en lugares concurridos, siendo esta práctica más frecuente entre los sintomáticos que entre los asintomáticos. Conclusiones. Este es el primer estudio de conocimientos, actitudes y prácticas sobre la Covid-19 en Venezuela. El conocimiento y las prácticas de los venezolanos podrían mejorar mediante el fortalecimiento de los programas de educación y capacitación. Esta información, obtenida durante la fase inicial de la pandemia en Venezuela, podría contribuir al diseño de estrategias de promoción y prevención de la Covid-19.

Abstract Introduction: The studies on knowledge, attitudes, and practices (KAP) regarding COVID-19 help to identify erroneous concepts and inadequate practices related to the disease. This baseline information is essential to design effective strategies and improve adherence to prevention measures. Objective: To identify the COVID-19-related KAP in Venezuelan patients screened at the Hospital Universitario de Caracas triage tent. Materials and methods: We conducted a cross-sectional study among 215 patients between April 25th and May 25th, 2020, with in-person interviews using a KAP survey. Results: Most surveyed patients (53.5%) were asymptomatic. Most of them, both from the symptomatic and the asymptomatic groups, had adequate knowledge about the symptoms and transmission of the disease and the majority said they were practicing quarantine, frequent handwashing, and the use of face masks in public areas. However, the daily replacement of cloth face masks was more frequent in the asymptomatic group whereas replacement every three days was more frequent in the symptomatic group. Finally, more than half of the participants admitted having been in crowded places, a common practice among the symptomatic compared to the asymptomatic patients. Conclusions: This is the first KAP study in Venezuela about COVID-19. Knowledge and practices among Venezuelans could be improved by strengthening education and training programs. This information from the early phase of the pandemic in Venezuela may contribute to the design of COVID-19 promotion and prevention strategies.

Abstract: Twelve pine species naturally occur in the state of Hidalgo, of which, Pinus pinceana and P. greggii are listed as threatened. In this context it is necessary to generate information for Pinus species identification specially for immature individuals without seed cones. In this study we establish an identification key based on leaf anatomy for the identification of pine species occurring in the state of Hidalgo. Specimens from different localities were collected from which, permanent slides were prepared from transverse leaf sections and a character matrix was codified from leaf anatomy features and analyzed with UPGMA. The matrix was used to construct an identification key. The key allow for the identification of 10 out of the 12 species, including Pinus greggii a species under risk category. Pinus cembroides can only be differentiated from P. pinceana when it exhibits a semicircular shape in transverse section. External resin canals were only observed in Pinus subgenus Strobus and septal resin canals were only recorded for P. oocarpa. The number of resin canals may only be used as complementary for identification because of its high variation. UPGMA analysis generated two principal clusters, the first group included two interior clusters corresponding with subgenus Strobus species and subgenus Pinus species, the second principal cluster included only species from subgenus Pinus. This study contributes with a robust identification key for pine species at a local scale exclusively using secondary leaf anatomy characters.

Resumen: En el estado de Hidalgo se distribuyen, naturalmente, 12 especies de pinos, de las cuales, Pinus pinceana y P. greggii están clasificados en categorías de riesgo. En este contexto es necesario generar información para la identificación taxonómica de Pinus, únicamente con base en caracteres anatómicos de acículas en individuos jóvenes que carecen de estróbilos femeninos. El objetivo del presente estudio fue establecer una clave dicotómica para la identificación de pinos de Hidalgo, a partir de su anatomía foliar. Se recolectaron ejemplares en diversas localidades, se obtuvieron cortes transversales de las acículas, con ellos se codificó una matriz de caracteres, la cual fue sometida a un análisis de similitud UPGMA; y se elaboró una clave taxonómica. Se logran diferenciar 10 de los 12 taxones, que incluyen a Pinus greggii, especie bajo categoría de riesgo. Pinus cembroides se diferencia de P. pinceana, solo cuando la forma de la acícula, en corte transversal, es semicircular. Los canales resiníferos externos se observaron solamente en individuos del subgénero Strobus; y los septales en P. oocarpa. El número de canales resiníferos es utilizado de manera complementaria para identificar, debido a su alta variación. El análisis UPGMA resultó en dos agrupaciones principales, en la primera se recuperaron dos subgrupos correspondientes a las especies del subgénero Strobus y del subgénero Pinus; en la segunda pertenecen al subgénero Pinus. Se concluye que la clave es robusta para la identificación de especies de pinos a escala local, exclusivamente mediante caracteres anatómicos foliares.

INTRODUCTION: Chronic kidney disease of unknown etiology is occurring in various geographic areas worldwide. Cases lack typical risk factors associated with chronic kidney disease, such as diabetes and hypertension. It is epidemic in El Salvador, Central America, where it is diagnosed with increasing frequency in young, otherwise-healthy male farmworkers. Suspected causes include agrochemical use (especially in sugarcane fi elds), physical heat stress, and heavy metal exposure. OBJECTIVE: To evaluate the geographic relationship between unspecifi ed chronic kidney disease (unCKD) and nondiabetic chronic renal failure (ndESRD) hospital admissions in El Salvador with the proximity to cultivated crops and ambient temperatures. METHODS: Data on unCKD and ndESRD were compared with environmental variables, crop area cultivated (indicator of agrochemical use) and high ambient temperatures. Using geographically weighted regression analysis, two model sets were created using reported municipal hospital admission rates per ten thousand population for unCKD 2006- 2010 and rates of ndESRD 2005-2010. These were assessed against local percent of land cultivated by crop (sugarcane, coffee, corn, cotton, sorghum, and beans) and mean maximum ambient temperature, with Moran’s indices determining data clustering. Two-dimensional geographic models illustrated parameter spatial distribution. RESULTS: Bivariate geographically weighted regressions showed statistically signifi cant correlations between percent area of sugarcane, corn, cotton, coffee, and bean cultivation, as well as mean maximum ambient temperature with both unCKD and ndESRD hospital admission rates. Percent area of sugarcane cultivation had greatest statistical weight (p < 0.001; Rp² = 0.77 for unCKD). The most statistically signifi cant multivariate geographically weighted regression model for unCKD included percent area of sugarcane, cotton and corn cultivation (p < 0.001; Rp² = 0.80), while, for ndESRD, it included the percent area of sugarcane, corn, cotton and coffee cultivation (Rp² = 0.52). Univariate unCKD and ndESRD Moran�fs I (0.20 and 0.33, respectively) indicated some degree of clustering. Ambient temperature did not improve multivariate geographically- weighted regression models for unCKD or ndESRD. Local bivariate Moran�fs indices with relatively high positive values and statistical signifi cance (0.3.1.0, p < 0.05) indicated positive clustering between unCKD hospital admission rates and percent area of sugarcane as well as cotton cultivation. The greatest positive response for clustering values did not consistently plot near the highest temperatures; there were some positive clusters in regions of lower temperatures. Clusters of ndESRD were also observed, some in areas of relatively low chronic kidney disease incidence in western El Salvador. CONCLUSIONS: High temperatures do not appear to strongly infl uence occurrence of unCKDu proxies. CKDu in El Salvador may arise from proximity to agriculture to which agrochemicals are applied, especially in sugarcane cultivation. The fi ndings of this preliminary ecological study suggest that more research is needed to assess and quantify presence of specifi c agrochemicals in high-CKDu areas.

A total of 11 parasitic endohelminth taxa were found in 7 freshwater fish species of the subfamily Goodeinae in Zacapu Lake, Michoacan, Mexico. Six were adults (Margotrema cf. bravoae, Phyllodistomum sp., Saccocoelioides sogandaresi, Rhabdochona lichtenfelsi, Bothriocephalus acheilognathi and Caryophillidae gen. sp.), while the remaining 5 taxa (Clinostomum complanatum, Posthodiplostomum minimum, Tylodelphis sp., Eustrongylides sp. and Polymorphus brevis) were larvae. The taxa S. sogandaresi, Tylodelphis sp., and R. lichtenfelsi reached the highest levels of prevalence and mean abundance among all hosts, while the cestodes B. acheilognathi and Caryophillidae gen. sp. showed the lowest values. This study contributes with the inventory of the freshwater fish helminth fauna in Central Mexico Plateau, and particularly with the previous work that has been done with Goodeinae, a subfamily of freshwater fishes endemic to that part of the country.

En este trabajo se registran 11 taxa de helmintos endoparásitos de 7 especies de peces de la subfamilia Goodeinae del lago de Zacapu, Michoacán, en la mesa central de México. Seis taxa se registraron en estado adulto (Margotrema cf. bravoae, Phyllodistomum sp., Saccocoelioides sogandaresi, Rhabdochona lichtenfelsi, Bothriocephalus acheilognathi y Caryophillidae gen. sp.), en tanto que los 5 restantes correspondieron a larvas (Clinostomum complanatum, Posthodiplostomum minimum, Tylodelphys sp. y Eustrongylides sp. y Polymorphus brevis). Los taxa S. sogandaresi, Tylodelphis sp. y R. lichtenfelsi presentaron los valores más altos de prevalencia y abundancia en los peces estudiados, mientras que los céstodos B. acheilognathi y Caryophillidae gen. sp. presentaron los valores más bajos. Este estudio contribuye al inventario de la fauna helmintológica de peces de agua dulce de la mesa central de México y en particular al que ha sido realizado con Goodeinae, una subfamilia de peces dulceacuícolas endémica de esa parte del territorio nacional.

Introduction: lipid extracts from the fruits of Serenoa repens, a native palm from the United States of America, are used to treat benign prostate hyperplasia. Although this species was introduced in the National Botanic Garden of Cuba some years ago, the lipid extracts of its fruits had not been studied yet. Objective: to determine the main organoleptic, physical and chemical characteristics of lipid extracts from the fruits of S. repens harvested in Cuba. Methods: dried fruits and fresh ripe fruits of S. repens were harvested. Fresh fruits were dried at room temperature and at 80 ºC. The three groups of dried fruits were grounded and extracted with hexane in Söxhlet equipment. The main characteristics of the dried lipid extracts were determined. The studied components were determined by gas chromatography, in some cases with mass spectrometry detection. Results: organoleptic and physical characteristics as well as the contents of fatty acids (major components) and ethyl esters of the studied extracts agreed with that described in literature, whereas those of sterols and fatty alcohols were higher than those previously reported for this species. some fatty alcohols not previously reported in these extracts, that is, 1-eicosanol, 1-docosanol, 1-heptacosanol, 1-nonacosanol, 1-dotriacontanol and 1-tetratriacontanol.were also identified. Conclusions: Generally speaking, the lipid extracts from the fruits of S. repens harvested in Cuba presented characteristics similar to those reported for the extracts of this species, although some differences were also found, such as the content of sterols and fatty alcohols and the presence of some fatty alcohols not previously reported in the literature.

Introducción: los extractos lipídicos de los frutos de Serenoa repens, una palma nativa de los EE. UU., se usan para tratar la hiperplasia prostática benigna. Aunque esta especie fue introducida en el Jardín Botánico Nacional de Cuba hace algunos años, los extractos lipídicos de sus frutos aún no habían sido estudiados. Objetivo: determinar las principales características organolépticas, físicas y químicas de extractos lipídicos obtenidos de frutos de S. repens recolectados en Cuba. Métodos: se recolectaron frutos secos y frutos maduros frescos de S. repens, los últimos se secaron a temperatura ambiente y a 80 ºC. Los 3 grupos de frutos secos se molieron y extrajeron con hexano en Söxhlet. Los extractos lipídicos se secaron y se determinaron sus principales características. Los componentes estudiados se determinaron mediante cromatografía de gases, en algunos casos con detección por espectrometría de masas. Resultados: los extractos presentaron características organolépticas y físicas, así como contenidos de ácidos grasos (componentes mayoritarios) y ésteres etílicos que coincidieron con lo descrito en la literatura, mientras que los contenidos de esteroles y alcoholes grasos resultaron superiores a los publicados antes para esta especie. También se identificaron alcoholes grasos no encontrados previamente en estos extractos: 1-eicosanol, 1-docosanol, 1-heptacosanol, 1-nonacosanol, 1-dotriacontanol y 1-tetratriacontanol. Conclusiones: de manera general, los extractos lipídicos de frutos de S. repens recolectados en Cuba presentaron características similares a las reportadas para los extractos de esta especie, aunque se encontraron algunas diferencias, como son mayores contenidos de esteroles y alcoholes grasos, y la presencia de algunos alcoholes grasos no identificados antes.

Introduction: the Salvia coccinea L. species, known as banderilla, is used in Cuba as an ornamental plant. Nevertheless, some traditional medical uses have been reported in other countries without reports of pharmacological studies. No phytochemical study has been made with plants of this species growing in Cuba. Objective: to carry out the phytochemical study of hydroalcoholic extracts from stems, leaves and flowers of the Salvia coccinea L. species. Methods: stems, leaves and flowers were collected, washed, disinfected, dried at 40 °C and independently extracted under reflux with a EtOH/H2O (60:40) mixture for 2 h at a solute-solvent ratio of 1:10. Results: compounds identified in both extracts were saponins, sugars, bitter principles, phenols, tannins, amino groups, alkaloids and flavonoids. The lyophilized extract from leaves and flowers contained 9.02 % of total polyphenols. Conclusions: several groups of compounds were found in the S. coccinea L. that grows in Cuba, such as flavonoids and alkaloids, and they could be of potential pharmacological interest. These results encouraged to continue the study of extracts from this plant and to begin evaluating their pharmacological effects.

Introducción: la especie Salvia coccinea L., conocida como banderilla, se emplea en Cuba solo como ornamental, aunque en otros países tiene algunos usos etnomédicos sin que se le hayan reportado estudios farmacológicos. A las plantas de esta especie que crecen en Cuba no se le han realizado estudios fitoquímicos. Objetivo: realizar un tamizaje fitoquímico de los extractos hidroalcohólicos de tallos, flores y hojas de la especie Salvia coccinea L. Métodos: se recolectaron los tallos, así como las hojas y flores, se lavaron, desinfectaron, secaron a 40 ºC y extrajeron de forma independiente a reflujo con una mezcla EtOH/H2O (60:40) a una relación soluto-disolvente de 1:10 durante 2 h. Los extractos se filtraron y se les hicieron las pruebas fitoquímicas. Resultados: los grupos de compuestos identificados en los 2 extractos fueron saponinas, azúcares, principios amargos, fenoles, taninos, grupos amino, alcaloides y flavonoides. El extracto liofilizado de las hojas y flores presentó 9,02 % de polifenoles totales. Conclusiones: en la S. coccinea L. que crece en Cuba se encontraron varios grupos de compuestos, entre estos flavonoides y alcaloides, los que pudieran tener interés farmacológico potencial. Estos resultados conminan a continuar el estudio de los extractos de esta planta y a iniciar la evaluación de sus efectos farmacológicos.

Plants and amendments increase quality of the tepetates once these hard layers, abundant in the Mexican Volcanic Belt, have been rototilled. In tepetate, which has a mass structure and lacks organic reserves, the addition of organic matter (OM) has proven to have a significant effect on fertility by supplying N and P, essential for the development of biota, and which promotes a stable structurization. Although it is known that soil quality is related to the nature of the organic compounds, there are few studies referring to the basic compounds of OM, once it has been incorporated into hard layers such as tepetate. The objective of the present study was to quantify the total organic carbon, polysaccharides, humic acids and fulvic acids, supplied to the tepetate by cultivation of fig (Ficus carica L.) and Rhodes grass (Chloris gayana Kunth), with the addition of bovine manure and fertilizer, for two years. The experiment was conducted in the greenhouse with duripán tepetate. The equivalent of 72 Mg ha-1 of manure was applied per experimental unit and fertilization dose of 80-80-20 for fig and 250-200-00 for grass. The manure doubled the organic carbon content of the tepetate from the first months of application. The fertilizer influenced the production of polysaccharides. The plants, with and without amendments, provided an increase of as much as 100% of organic carbon and polysaccharides. The humic and fulvic acids were not modified by the treatments. The highest content of carbon and polysaccharides was at 12 months.

Las plantas y enmiendas aumentan la calidad de los tepetates una vez que se han roturado estas capas duras, abundantes en el Eje Neovolcánico Mexicano. En el tepetate, que posee estructura masiva y carece de reservas orgánicas, la adición de materia orgánica (MO) ha mostrado un efecto significativo en la fertilidad al aportar N y P, esenciales para el desarrollo de biota, al tiempo que favorece una estructuración estable. Aunque se sabe que la calidad del suelo se relaciona con la naturaleza de los compuestos orgánicos, son escasos los estudios acerca de los componentes básicos de la MO, una vez que se ha incorporado a capas duras como el tepetate. El objetivo del presente estudio fue cuantificar el carbono orgánico total, polisacáridos, ácidos húmicos y ácidos fúlvicos, aportados al tepetate por cultivo de higuera (Ficus carica L.) y pasto Rhodes (Chloris gayana Kunth), con adición de estiércol bovino y fertilizante, por dos años. El experimento se realizó en invernadero, con tepetate tipo duripán. Se aplicó el equivalente a 72 Mg ha-1 de bovino por unidad experimental y dosis de fertilización de 80-80-20 para higuera y 250-200-00 para pasto. El estiércol duplicó el contenido de carbono orgánico del tepetate desde los primeros meses de aplicación. El fertilizante influyó en la producción de polisacáridos. Las plantas, con y sin enmiendas, propiciaron un aumento de hasta 100% de carbono orgánico y polisacáridos. Los ácidos húmicos y fúlvicos no se modificaron por los tratamientos. El mayor contenido de carbono y polisacáridos fue a los 12 meses.

Abstract: One of the main problems in México is soil degradation due to the change of its use as cropland; this change causes deterioration, which may lead to total loss and outcrop of tepetate. Tepetates are hardened layers of volcanic origin in zones of the Trans-Mexican Volcanic Belt; they present low percentages of organic matter and of nutrients, and a massive structure, which makes them impermeable and limits plant growth. The objective of this study was to evaluate the effect of three organic amendments, one vegetal species (Ficus carica L.), mycorrhiza (Glomus spp), and time, on the physical and chemical characteristics of a fragmented tepetate. The experimental design was completely randomized with a 4×3×2 factorial arrangement of treatments with the following factors and levels: 1) amendment (without amendment, compost, vermicompost, and manure), 2) fig tree (without plant, with plant, and plant plus inoculum); time (6 and 12 months). Application of organic matter, fig tree, and mycorrhiza favored the formation of aggregates from tepetate and their stability. The pH, CIC, content of organic matter, and exchangeable cations of tepetate were favorably modified and allowed developing of the fig tree. The changes in physical and chemical characteristics of tepetate through addition of amendments, time, and fig tree, favor its habilitation and incorporation to productivity.

Resumen: En México uno de los principales problemas es la degradación del suelo debido al cambio de su uso como tierras de cultivo; este cambio ocasiona un deterioro que puede llegar a la pérdida total y el afloramiento del tepetate. Los tepetates son capas endurecidas de origen volcánico en zonas del Eje Neovolcánico Transmexicano, presentan bajos porcentajes de materia orgánica y nutrimentos, y una estructura masiva, lo que los hace impermeables y limita el crecimiento de las plantas. El objetivo de este estudio fue evaluar el efecto de tres enmiendas orgánicas, una especie vegetal (Ficus carica L.), micorriza (Glomus spp) y tiempo, en las características físicas y químicas de un tepetate fragmentado. El diseño experimental fue completamente al azar con un arreglo factorial de tratamientos (4×3×2) con los siguientes factores y nivieles: 1) la enmienda (sin enmienda, composta, vermicomposta y estiércol); 2) higuera (sin planta, con planta y planta más inóculo): 3) tiempo (6 y 12 meses). La aplicación de materia orgánica, la higuera y la micorriza favorecieron la formación de agregados a partir de tepetate y su estabilidad. El pH, la CIC, el contenido de materia orgánica y los cationes intercambiables del tepetate se modificaron favorablemente y permitieron el desarrollo de la higuera. Los cambios en las características físicas y químicas del tepetate por adición de enmiendas, el tiempo y la higuera favorecen su habilitación e incorporación a la productividad.

Strongyloides stercoralis es un parásito intestinal, cuya prevalencia es usualmente subestimada en Costa Rica, porque se emplea solo el examen directo de las muestras de heces; mientras que, para S. stercoralis es necesario emplear métodos más sensibles, como el Baermann o el cultivo en agar. En otros países se ha considerado a los pacientes psiquiátricos como un grupo de riesgo para esta parasitosis; por lo que estudiamos un grupo de pacientes (n=108) y del personal (n=71) del Hospital Nacional Psiquiátrico, analizado mediante una modificación del método de Baermann y el examen directo estándar. Los parásitos más frecuentes fueron Endolimax nana (20%), Entamoeba coli (16%), Giardia duodenalis (4%), y dos casos de S. stercoralis, uno del grupo de pacientes y el otro del personal. Este informe corrobora la importancia del método de Baermann, porque los dos casos de S. stercoralis encontrados, además de dos de Trichuris y otros dos de uncinarias solo fueron detectados por el método de Baermann. Adicionalmente, la prevalencia global de parásitos intestinales encontrada fue un 10% superior a la prevalencia informada para el país en la encuesta nacional de 1996. Los datos presentados corroboran que los pacientes psiquiátricos representan un grupo de alto riesgo para los parásitos intestinales y cualquier otro agente transmitido por contaminación fecal.

Strongyloides stercoralis is an intestinal parasite, which prevalence is usually underestimated in Costa Rica, because the stool samples are analyzed only by direct fecal smears; whereas, for S. stercoralis analysis is necessary to use more sensible methods; such as the Baermann or agar culture methods. In other countries the psychiatric patients are considered as a risk group for this parasite. For this reason, a group of patients (n=108) and personal (n=71) from the National Hospital of Psychiatric were studied using a modification of the Baermann method and the standard direct fecal analysis. The most frequent parasites found were Endolimax nana (20%), Entamoeba coli (16%), Giardia duodenalis (4%), and two cases of S. stercoralis were diagnosed, one from the patients and the other in the staff. This report stresses the importance of the use of Baermann method, because the two cases of S. stercoralis found and other two cases of Trichuris and another two of hookworms were diagnosed only with this method. The global prevalence of intestinal parasites of the psychiatric patients was 30%, a 10% higher than the prevalence described for the country, according to the national survey from 1996. Our data corroborate that the psychiatric patients represent a high-risk group for intestinal parasites and also to any other agent transmitted by fecal contamination.