Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Peperomia subgénero Tildenia es un grupo poco conocido de especies geofíticas de hábitats estacionales en 2 hotspots de biodiversidad (México-Guatemala y Perú-Bolivia) con pocas especies en los países de enmedio. El trabajo de campo realizado recientemente en México y América Central, combinado con un estudio detallado de ejemplares de herbario de este subgénero, resultó en el descubrimiento de 12 especies nuevas, que se describen e ilustran. Además, una variedad anteriormente publicada es elevada a la categoría de especie. Se incluyen datos de distribución, hábitat y fenología, comparaciones detalladas con otras especies, así como una clave de identificación para todas las especies del subgénero en la región estudiada.

El leucismo es la reducción de la pigmentación parcial o total del pelaje, pero que mantiene la coloración normal de los ojos y la piel. Aquí se presenta el registro de un individuo de la musaraña endémica de México Cryptotis mexicana que presenta esta condición.  Esta coloración, considerada anormal en estado silvestre, puede incrementar la presión de selección sobre esos individuos.  Además, es un reflejo indirecto de la variabilidad genética en las poblaciones naturales.

En este estudio se modeló el nicho ecológico proyectado como distribución potencial de 313 especies amenazadas en Mesoamérica, Chocó y los Andes tropicales, según las listas de la UICN. De estas especies, 285 fueron plantas y 28 fueron vertebrados terrestres. La superposición de las distribuciones de las especies amenazadas cubrió prácticamente toda la región. Ecuador mostró cerca del 30% de su área con 50 especies. Colombia, Costa Rica, Guatemala, Nicaragua y Panamá mostraron > 50, aunque en < 0.5% del área de cada país. Costa Rica, Ecuador, Nicaragua y Panamá mostraron de 21 a 50 especies en > 50% de su área. El Salvador y Honduras, de 11 a 20 en > 50% de su área y México de 1 a 5 especies en > 50% de su área. La distribución de estas especies en áreas transformadas (agricultura y áreas urbanas) varió del 11al 30%; El Salvador, Panamá y Guatemala mostraron > 50% de la distribución; Colombia, Honduras y México < 40%; Belice y Ecuador, < 25% cada uno; El Salvador, Honduras, Panamá, Nicaragua y México mostraron altos porcentajes de distribución para las clases Amphibia, Liliopsida, Polipodiopsida y los órdenes Asterales, Fabales, Laurales, Myrtales, Scrophulariales y Rubiales.

Se presentan nuevos registros de microlíquenes para el norte de Argentina. Se incluyen comentarios de los siguientes taxones: Coniocarpon cinnabarinum (Arthoniaceae); Schistophoron tenue (Graphidaceae); Reimnitzia santensis (Thelotremataceae); Phyllopeltula steppae (Peltulaceae); Dichosporidium nigrocinctum, Enterographa pallidella y Syncesia effusa (Roccellaceae) y Tylophoron crassiusculum (Caliciales, incertae sedis).

The objective of this research was characterize and determine the effect of native strains of Azotobacter spp. on the vegetative growth of Lycopersicon esculentum Mill. "Tomato" as an alternative to the indiscriminate use of chemical fertilizers. Samples were taken from roots and rhizosphere soil of vegetables from which dilutions (10-4) in Ashby-sucrose broth and incubated at 30 °C to observe a yellow color, turbidity and surface film. The genus Azotobacter was identified in mineral agar without nitrogen and Ashby-benzoate, obtaining 96 strains with a yield of 7.10 to 57.99 mgL-1 indoleacetic acid, 0.13 to 1.64 mgL-1 of fixed nitrogen as ammonium and up to 1.61% efficiency in the solubilization of phosphate Bayovar rock. It obtained a cell suspension (108) of each of the four strains with the highest values and inoculated independently and in consortium, as well as a combination with 50% urea-100 % phosphate rock in the rhizosphere of Rio Grande tomato, in a completely randomized design. The entire native strains increased height, root volume, total dry matter, shoot and root, compared with absolute control.

Greenhouse vegetable production in México and worldwide has become important. Following greenhouses automation, a simple controller was designed to open and close shading nets to reduce incident radiation and excessive evapotranspiration. Irrigation period were radiation controlled and did not turn on the pump with clouds or moon radiation, saving 35% of water. The nets remained closed during the night and were opened during scarce radiation. In the tomato greenhouse experiment, every three months analysis was carried on manual and automatic net control. Maximum incident radiation was achieved in May and August when no shading nets were used. Air temperature increased to 28°C in August decreasing by 50% fruit size. Fruit temperature decreased 2.5°C when nets were used decreasing tomato cracking.

The cotton mechanized harvest is very advantageous for the collection manual, primarily because operating costs are reduced and the operation of providing the large-scale cultivation. But when the operation is not performed following criteria, can lead to losses and thus reducing gains to the farmer. This study aimed to quantify losses in the harvest of cotton in the city of Stone Ipameri-GO, in experiment conducted on three cotton properties, used the completely randomized design with 10 replications. In the three properties studied the losses in the soil out on the losses in the plant, with all properties, these losses were around 59% of total losses. Overall losses found stood at round 5.1%, 3.5% and 7.5% respectively for the three properties, remaining within the limits considered acceptable.

In order to evaluate the response camu camu’s plants in plantations initial undergoing training pruning, an experiment was installed in EE - IIAP-Ucayali, under a design randomized complete block, with 3 replications, making use of 20 plants per experimental unit. The pruning treatments were performing at different heights from the base of the stem, it was considered T0 [witness without pruning], T1 [pruning to 10 cm from the base], T2 [pruning to 20 cm from the base] and T3 [pruning to 40 cm from the base] in plants of known provenance. The investigation was directed to evaluate the number of shoots, shoot growth, plant height, basal diameter, crown diameter and number of branches. After of 9 months of evaluation was found significant differences between the variables except in top diameter. In the variable Height, treatment T0 [witness without pruning] outstanding because they were not pruned, among the remaining treatments has similarly behaved, surpassing the control treatment by 267 %. In addition to this, the basal diameter was found that T1 [pruning to 10 cm from the base] has a better performed with an average value of 1.96 cm compared with the control (1.7cm). The pruning had a positive influence in the number of branches, with an average of 13.4 branches compared with T0 that get 3.1 branches on average, its shows that the pruning can increased up the production of branches to 432.3%.

The objective of this research was to determine the hypolipidemic activity of the fruit of Physalis peruviana "tomatillo" in a model of acute hyperlipidemia induced by triton. Mus musculus var. swis males as experimental animals. We worked with four groups of mice, the white group received distilled water orally and saline intraperitoneally, the control group received distilled water orally and intraperitoneally triton, the problem group 1 received orally 0.05g/100g Physalis peruviana extract intraperitoneally and triton and the problem group 2 received orally 0.2g/100g extract of Physalis peruviana and triton intraperitoneally. After 24 hours of administering the treatments were performed measurements of serum cholesterol and triglycerides. Mean levels of cholesterol (mg/dL) were: 58.87 ± 11.54 (white), 121.71 ± 15.00 (control), 58.08 ± 9.21 (Problem 1) and 66 78 ± 16.77 (Problem 2). Average levels of triglycerides (g /L) were: 0.48 ± 0.07 (white), 1.84 ± 0.18 (control), 0.34 ± 0.10 (Problem 1) and 0.94 ± 0.25 (Problem 2). We found significant reductions (p <0.000) concentrations of both cholesterol and triglycerides in relation to those obtained in the group treated only with Triton.

En Cuba, la formación masiva de médicos ha requerido un elevado esfuerzo en elorden de los recursos humanos y materiales. Estos últimos incluyen los libros detexto para uso de estudiantes y profesores.La elaboración de textos de autores cubanos, además de favorecer la adecuación anuestros programas y la comprensión por parte de los estudiantes, contribuye demodo significativo al ahorro.En este trabajo, se presenta, con un análisis histórico y documental, la producciónbibliográfica de los profesores de Bioquímica de la Universidad de Ciencias Médicasde La Habana.Colofón de este esfuerzo fue la publicación del texto Bioquímica Médica, en cuatrotomos, con una elaboración y presentación de elevada calidad y merecedor delPremio Anual del MINSAP 1999. Pionero en esta actividad fue el Profesor Roberto Alonso Borges, a quien se unieronotros docentes de experiencia y, ulteriormente, nuevas generaciones de profesoresliderados por la Profesora Lidia Cardellá Rosales.Palabras clave: Libros de texto. Bioquímica. Autores cubanos.