Resumen El objetivo de este estudio fue describir la diversidad, composición y estructura de la vegetación leñosa en una sección de la selva baja caducifolia (SBC) en Lerma, Campeche. Entre agosto y septiembre 2018, se delimitaron 10 parcelas de 10 × 10 m2 (1 000 m2 en total) midiendo todos los individuos de 1 cm de DAP (diámetro a la altura del pecho, 1.30 m). Se describió la estructura del sitio basado en los valores relativos de densidad, frecuencia y dominancia (IVI), así como la distribución de clases diamétricas. La diversidad se estimó con el índice de Shannon-Wiener (H’), mientras que la equidad fue medida por el índice de Pielou. Se registraron 40 especies leñosas, pertenecientes a 35 géneros y 19 familias. El índice H’ tuvo un valor de 2.92, y el índice de Pielou fue de 0.79, la densidad fue de 8 950 ind ha-1. Gymnopodium floribundum (204 individuos) y Lonchocarpus xuul (129 individuos) fueron las especies más abundantes. Bursera simaruba y Lysiloma latisiliquum mostraron valores diamétricos más altos (36 y 28.6 cm de DAP, respectivamente). Las familias Rubiaceae (ocho especies) y Fabaceae (cinco especies), fueron las más representativas. Las especies con mayor IVI fueron Gymnopodium floribundum (48.24%), Lonchocarpus xuul (29.12%), Bursera simaruba (26.11%) y Lysiloma latisiliquum (24.98%), siendo estas especies las más importantes en la estructura de la SBC en el sitio. La distribución de las clases diamétricas sugiere que la sección de la SBC en Lerma Campeche se encuentra en un adecuado estado de regeneración.

Abstract The objective of this study was to describe the diversity, composition, and structure of the woody vegetation in a section of LDF in Lerma, Campeche. Between August and September 2018, 10 plots of 10 × 10 m2 (1 000 m2 in total) were delimited, measuring all woody individuals with diameter at breast height (DBH = 1.30 cm). The structure of the site was described based on the relative values of density, frequency, and dominance (IVI), as well as the distribution of diameter classes. Diversity was estimated with the Shannon-Wiener index (H'), while equity was measured by the Pielou index. 40 woody species were recorded, belonging to 35 genera and 19 families. The H' index had a value of 2.92, and the Pielou index was 0.79, the density was 8 950 ind ha-1. Gymnopodium floribundum (204 individuals) and Lonchocarpus xuul (129) were the most abundant species. Bursera simaruba and Lysiloma latisiliquum showed higher diameter values (36 and 28.6 cm DBH, respectively). The families Rubiaceae (eight species), Fabaceae (five species), Ebenaceae and Polygonaceae (three species each) were the most representative. The species with the highest IVI were Gymnopodium floribundum (48.24%), Lonchocarpus xuul (29.12%), Bursera simaruba (26.11%) and Lysiloma latisiliquum (24.98%), these species being the most important in the structure of the LDF in the site. The distribution of the diameter classes suggests that the section of the LDF in Lerma Campeche is in an adequate state of regeneration.

Abstract The Puerto Pizarro mangrove is part of the Tumbes mangrove, the largest in Peru; it is also the mangrove with the greatest anthropic impact in the region; in this area, no studies have been carried out on the status of its population of Rhizophora mangle, the most important mangrove species in the Peruvian mangroves. The objective of this research was to establish the structural characteristics of R. mangle in the Puerto Pizarro mangrove. The study was carried out by subdividing the research area into three zones (A, B and C), in which 41 plots of 1 ha each were selected, in each plot a sub-area of 0.25 ha (50 m x 50 m) was taken). In these sub-areas, mangrove trees of the species Rhizophora mangle, Laguncularia racemosa and Avicennia germinans were evaluated regarding their structural characteristics: diameter at breast height (DBH), height, basal area, density, frequency, dominance and index value of ecological importance (IVI). It was found that R. mangle had a greater DAP, height and basal area than the other species; also, higher density, frequency, dominance and relative IVI (adjusted to 100%) than the other species with values of 51.5%, 100%, 82.6% and 53.3%, respectively. The research findings allow us to conclude that the population of R. mangle in the Puerto Pizarro mangrove is a mature population, with a predominance of stems and latizales. However, its structural characteristics are not homogeneous throughout the Puerto Pizarro area, since zone A, with less anthropic impact and lower salinity, has R. mangle trees with better structural characteristics than those in zones B and C in which there is greater anthropic activity and greater salinity.

Resumen El manglar de Puerto Pizarro forma parte del manglar de Tumbes, el más grande del Perú; es también el manglar con mayor impacto antrópico en la región; en este no se han realizado estudios sobre el estado de su población de Rhizophora mangle, la especie de mangle más importante de los manglares peruanos. Esta investigación buscaba establecer las características estructurales de R. mangle en el manglar de Puerto Pizarro. El estudio se realizó subdividiendo el área de investigación en tres zonas (A, B y C), en las cuales se seleccionaron 41 parcelas de 1 ha cada una, en cada parcela se tomó una sub-área de 0,25 ha (50 m x 50 m). En estas sub-áreas se evaluaron los árboles de mangle de las especies Rhizophora mangle, Laguncularia racemosa y Avicennia germinans respecto a sus características estructurales diámetro a la altura del pecho (DAP), altura, área basal, densidad, frecuencia, dominancia e índice de valor de importancia ecológica (IVI). Se encontró que R. mangle presentó un mayor DAP, altura y área basal que las otras especies; así también, mayor densidad, frecuencia, dominancia e IVI relativos (ajustados al 100%) que las otras especies con valores de 51,5%, 100%, 82,6% y 53,3%, respectivamente. Los hallazgos de la investigación permiten concluir que la población de R. mangle del manglar de Puerto Pizarro es una población madura, con predominancia de fustales y latizales. En Puerto Pizarro, sus características estructurales no son homogéneas, ya que la zona A, con menor impacto antrópico y menor salinidad, presenta árboles de R. mangle con mejores características estructurales que los de las zonas B y C, donde hay mayor actividad antrópica y mayor salinidad.

Abstract At Cerro de la Muerte, mosses and lichens are extracted for commercial use, and despite their socioeconomic and ecological importance in the high-altitude towns and ecosystems of Costa Rica, few studies have been assess their biological importance. In this study, some of the biological characteristics of mosses and lichens were evaluated to improve their conservation in Cerro de la Muerte. Two sites were selected, one disturbed (pasture) and one not disturbed (protected area), where transects and subplots were established to determine the diversity of species in both sites. In these same transects, samples of mosses and lichens were collected to determine the relative growth rate (TCR) and water retention capacity. A dominance of the moss Leptodontium sp. for the distrubed site, while in protected site the dominant moss is Sphagnum sp. The highest TCR and water retention capacity was found in Sphagnum sp. with 70%, and 26% Leptodontium sp. Therefore, to conserve the mosses and lichens in the highlands of Cerro de la Muerte and the ecosystems that depend on these organisms, it is important to keep harvesting mosses of the genus Leptodontium sp. for commercialization, since this will control its dominance in the disturbed site, and the second in dominance in the protected site. This species has a high five-month TCR and a low water retention capacity.

Resumen En el Cerro de la Muerte se extraen musgos y líquenes para comercializar, sin embargo, a pesar de su importancia socioeconómica y ecológica en los ecosistemas de altura de Costa Rica, se han registrado pocos estudios sobre sus características biológicas. En este estudio se evaluaron las características biológicas de musgos y líquenes para mejorar su conservación en el Cerro de la Muerte. Se seleccionaron dos sitios, uno intervenido (potrero) y otro no intervenido (área protegida), donde se establecieron transectos y subparcelas para determinar la diversidad de especies en ambos sitios. En esos mismos transectos se recolectaron muestras de musgos y líquenes para conocer la tasa de crecimiento relativa (TCR) y la capacidad de retención de agua. Se observó dominancia del musgo Leptodontium sp. para el sitio intervenido, mientras que en el sitio no intervenido el musgo dominante es Sphagnum sp. La TCR y la capacidad de retención de agua más alta la tuvo el Sphagnum sp., con 70 %, seguido de Leptodontium sp., con un 26 %. Por tanto, para conservar los musgos y líquenes en las tierras altas del Cerro de la Muerte y los ecosistemas que dependen de estos organismos, se consideró viable seguir cosechando para la comercialización el musgo del género Leptodontium sp., debido a que es el de mayor dominancia en el sitio intervenido, y el segundo en dominancia en el sitio no intervenido, con una alta TCR a cinco meses y una baja capacidad de retención de agua.

ABSTRACT: The zooplankton species present in Argopecten purpuratus “fan shell” culture areas were determined in Vichayo, Sechura, Piura; The physical and chemical parameters were related to the composition of the zooplankton; The sampling unit was 100 ml of water, in which zooplankton, temperature, pH, oxygen and salinity were evaluated. 180 samples were collected from 5 sampling points, chosen at random, using drag and vertical sampling, for six months. ; species are determined using taxonomic keys and the appropriate equipment to evaluate physical and chemical factors. The data obtained were analyzed using descriptive and inferential statistics, with decisions of 95% confidence. The results indicate that the phyllum Arthropoda predominates in the zooplankton and within it, the Copepoda class; The physical and chemical values were within the established ranges. Concluding that of 100% of individuals of the zooplankton species community present in the evaluated areas, 69.84% of them belong to the Phylum Arthropoda; and that the zooplankton community remains in dynamic equilibrium due to low dominance and high values of species richness, diversity and equitability.

RESUMEN: Se determinaron las especies de zooplancton presentes en áreas de cultivo de Argopecten purpuratus “concha de abanico” Vichayo, Sechura, Piura; se relacionaron los parámetros físicos y químicos con la composición del zooplancton; la unidad muestral fue de 100 ml de agua, en la que se evaluó zooplancton, temperatura, pH, oxígeno y salinidad, fueron colectadas 180 muestras en 5 puntos de muestreo elegidos al azar, muestreos por arrastre y vertical durante seis meses; determinándose las especies con el uso de claves taxonómicas y oxímetro, peachímetro y refractómetro para evaluar factores físicos y químicos. Los datos obtenidos fueron analizados mediante estadística descriptiva e inferencial, con decisiones de 95% de confianza. Los resultados indican que en el zooplancton predomina el phyllum Arthropoda y dentro de él, la clase Copepoda; los valores físicos y químicos se hallaron dentro de los rangos establecidos. Concluyéndose que del 100% de las especies de zooplancton presentes en las áreas evaluadas, el 69,84% pertenecen al phylum Arthropoda; y que, la comunidad de zooplancton se mantiene en equilibrio dinámico debido a una baja dominancia y valores elevados de riqueza de especies, diversidad y equitabilidad.

ABSTRACT This article analyzes Francisco Dornelles’ term at the Ministry of Finance in 1985. In addition to filling the existing gap in historiography, it reconstructs the thinking and economic actions of Dornelles and Tancredo Neves. Both were conservatives, endorsing a “monetarist” diagnosis of the Brazilian crisis. This conservatism translated into a relative continuation of the austerity policy implemented by Delfim Netto. It is argued that Dornelles’ departure from the Ministry of Finance marks an important turning point in Brazil’s economic history. FGV-RJ and the “delfinist” faction of FEA-USP lose their hegemony over economic policy, creating space for other schools, such as Unicamp and PUC-Rio. 1985 historiography Neves conservatives monetarist “monetarist crisis Netto Brazils Brazil s history FGVRJ FGV RJ delfinist “delfinist FEAUSP FEA USP schools PUCRio. PUCRio PUC Rio. Rio PUC-Rio 198 19 1

RESUMO O texto analisa a gestão de Francisco Dornelles no Ministério da Fazenda em 1985. Além de preencher a lacuna existente na historiografia, reconstrói-se o pensamento e a atuação econômica de Dornelles e Tancredo Neves. Ambos eram conservadores, esposando um diagnóstico “monetarista” sobre a crise brasileira. Esse conservadorismo se traduzia em um relativo continuísmo da política de arrocho implementada por Delfim Netto. Argumenta-se que a saída de Dornelles da Fazenda marca uma importante virada na história econômica do Brasil. FGV-RJ e a ala “delfinista” da FEA-USP perdem a hegemonia sobre a política econômica, abrindo espaço para outras escolas, como Unicamp e PUC-Rio. 1985 historiografia reconstróise reconstrói Neves conservadores monetarista “monetarista brasileira Netto Argumentase Argumenta Brasil FGVRJ FGV RJ delfinista “delfinista FEAUSP FEA USP escolas PUCRio. PUCRio PUC Rio. Rio PUC-Rio 198 19 1

ABSTRACT Holopelagic Sargassum has been causing massive strandings on tropical Atlantic Ocean shorelines. Describing the microbiome associated with Sargassum and how it changes after stranding is important to identify potential microbial introductions to coastal environments, as well as sources of potential biotechnological resources. In this study, stranding simulation exploratory experiments were conducted for S. fluitans III and S. natans VIII on shipboard with minimum external influence. Samples for microbiome identification were collected just after removing healthy Sargassum from the seawater (0 hr) and after 24 and 48 hrs of stranding simulation under environmental conditions. The bacterial community was identified by sequencing 16S rRNA gene V3-V4 hypervariable regions, generating a total of 1,565 Amplicon Sequence Variants (ASVs). Of those, 588 were shared between Sargassum species and only 25 persisted throughout the stranding. Stranding also changed the dominance of Microtrichales and Rhodobacterales orders at 0 hr to Alteromonadales and Vibrionales after 24 hrs of exposure, the latter representing up to 92% of the relative abundance in the bacterial community. The increase in Vibrionales reinforces the need to monitor stranding sites for any potential pathogenic bacteria. At the functional level, phototrophs were the main group at 0 hr, shifting to chemoheterotrophs and fermentation within the first 24 hrs of Sargassum exposure to air conditions. The fermentative groups native to Sargassum use stranded biomass as substrate for growth, and therefore constitute the bacteria with higher biotechnological potential. shorelines environments resources study S influence ( 2 4 conditions V3V4 VV V3 V4 V V3-V regions 1565 1 565 1,56 ASVs. ASVs . (ASVs) those 58 92 level growth V3V 156 56 1,5 (ASVs 5 9 15 1,

Objectives: Electroconvulsive therapy (ECT) is commonly indicated for refractory psychiatric disorders. However, little research has compared response across diagnoses. Here, we aimed to evaluate the relative impact of diagnosis and clinical staging as response predictors in a cross-diagnostic sample. Methods: In a retrospective cohort of adult inpatients (n=287) who underwent at least six sessions of ECT, we investigated predictors of complete response (a clinical global impression of 1) to ECT. We use adjusted regression models to estimate the impact of clinical diagnosis and staging on complete response and dominance analysis to assess the relative importance of these predictors. Results: Those for whom a depressive episode was a primary indication for treatment were the most likely to have complete improvement, while those with psychosis were the least likely; clinical stage had a significant influence on outcome in all diagnoses. A diagnosis of psychosis was the strongest predictor of non-response. Conclusions: A diagnosis of psychosis (mainly schizophrenia) was the strongest predictor of non-response. We also found that clinical staging can aggregate information on ECT response that is independent of clinical diagnosis. Objectives (ECT disorders However diagnoses Here crossdiagnostic cross diagnostic sample Methods n=287 n287 n 287 (n=287 1 Results improvement nonresponse. nonresponse non response. non-response Conclusions mainly schizophrenia n=28 n28 28 (n=28 n=2 n2 2 (n=2 n= (n= (n

RESUMEN Los bosques estacionalmente secos (BES) se encuentran permanentemente amenazados por diversas actividades antrópicas y naturales que vienen mermando los servicios ambientales que ofrecen; en tal sentido y con la finalidad de contribuir al conocimiento ecológico de este tipo de ecosistema se realizó la caracterización vegetal de un BES del Marañón en el distrito de Utco, Celendín, Cajamarca, al norte de Perú. Se estratificaron tres zonas de estudio cada 300 m: desde los 850 a 1700 m snm; el muestreo se realizó en temporada húmeda utilizando 30 transectos Gentry modificados de 50 x 2 m (0.1ha), considerando una distancia mínima entre parcelas de 50 m; se registró información de composición vegetal; cuando los individuos presentaron un diámetro mayor a 1 cm se tomó el DAP y cuando fue menor a 1 cm se registro su presencia; la colecta botánica siguió la técnica convencional identificando las muestras en el herbario CPUN; se evaluaron los principales índices de diversidad y se realizó un Escalamiento Dimensional No Métrico (NMDS) con RStudio. Se registraron 52 especies y siete taxones a nivel de género distribuidos en 56 géneros y 25 familias de la subdivisión Angiospermae; 31 de hábito arbustivo, 10 herbáceas, nueve arbóreas, seis suculentas y tres trepadoras. Las familias más diversas fueron Fabaceae (11sp), Asteraceae (7sp) y Cactaceae (6sp). Se reportan 14 especies endémicas de Perú y nueve del BES Marañón. La diversidad de Margalef (DMg) y dominancia de Simpson (D) fueron altas para la Zona III; los índices de Sorensen (IS) y Jaccard (J) mostraron mayor similitud entre las Zonas I y II. La mayor abundancia y frecuencia relativa (AR FR) la tuvo Cienfuegosia tripartita (42,30%, 9,2%); la mayor área basal (AB) dominancia relativa (DR) e IVI, Eriotheca discolor (AB=629,8 m2/0,1ha, DR=84,7%, IVI=97,34). El patrón de distribución diamétrica altitudinal es predominantemente arbustivo.

ABSTRACT Seasonally dry forests (BES) are permanently threatened by several anthropic and natural activities that have been reducing the environmental services they offer; In this sense and with the purpose of contributing to the ecological knowledge of this type of ecosystem, the vegetal characterization of a BES of the Marañon was carried out in the district of Utco, Celendin, Cajamarca, in the north of Peru. Three study zones were stratified every 300 m: from 850 to 1700 m asl; Sampling was carried out in the wet season using 30 modified Gentry transects of 50 x 2 m (0.1ha), considering a minimum distance between plots of 50 m; plant composition information was recorded; when the individuals presented a diameter greater than 1 cm, the DAP was taken and when it was less than 1 cm, its presence was recorded; the botanical collection followed the conventional technique, identifying the samples in the CPUN herbarium; the main diversity indices were evaluated and a Non-Metric Dimensional Scaling (NMDS) was performed with RStudio. 52 species and 7 taxa at the genus level distributed in 56 genera and 25 families of the Angiospermae subdivision were recorded; 31 bushy, 10 herbaceous, nine arboreal, six succulents and three climbers. The most diverse families were Fabaceae (11sp), Asteraceae (7sp) and Cactaceae (6sp). Fourteen endemic species from Peru and nine from BES Marañon are reported. Margalef diversity (DMg) and Simpson dominance (D) were high for Zone III; Sorensen (IS) and Jaccard (J) indices showed greater similarity between Zones I and II. The greatest abundance and relative frequency (AR FR) was found by Cienfuegosia tripartita (42.30%, 9.2%); the highest basal area (BA) relative dominance (DR) and IVI, Eriotheca discolor (BA=629.8 m2/0.1ha, DR=84.7%, IVI=97.34). The elevational diametric distribution pattern is predominantly shrubby.

RESUMO: Microrganismos na rizosfera desempenham um papel importante no crescimento e saúde das plantas. Em todo o mundo, vários patógenos do solo atacam o Capsicum annuum causando danos significativos e perdas econômicas. Este estudo teve como objetivo determinar se a diversidade e composição das comunidades microbianas no solo da rizosfera de plantas de C. annuum é alterada significativamente pela murcha. Usamos o gene 16S rRNA para bactérias e a região espaçadora transcrita interna para fungos para caracterizar os microbiomas da rizosfera de plantas saudáveis e plantas com murcha. Os filos bacterianos mais abundantes foram Proteobacteria e Gemmatimonadetes, enquanto os filos fúngicos foram Ascomycota e Mucoromycota. A diversidade alfa bacteriana não mostrou diferenças significativas na riqueza e diversidade, mas mostrou uma diferença significativa na uniformidade e dominância das espécies. Táxons raros estavam presentes em condições saudáveis e murchas com abundância relativa < 1%. Em fungos, todos os estimadores avaliados apresentaram redução significativa na condição de murcha. A diversidade beta apresentou diferenças significativas na estrutura das comunidades bacterianas e fúngicas, que foram segregadas de acordo com as condições fitossanitárias. O mesmo aconteceu ao comparar a diversidade alfa e beta deste estudo baseado na agricultura orgânica com a de outros estudos baseados na agricultura convencional. Uma diferença significativa foi observada com os estimadores analisados segregando as comunidades da rizosfera dependendo do método de cultivo utilizado. Por fim, a análise de abundância diferencial não apresentou resultados significativos nas comunidades bacterianas; entretanto, nas comunidades fúngicas, os gêneros Fusarium, Thanatephorus, Rhizopus, Curvularia, Cladosporium e Alternaria foram mais abundantes na rizosfera de plantas murchas do que saudáveis. Várias espécies desses gêneros foram previamente relatadas como fitopatógenos de várias plantas, incluindo C. annuum.

ABSTRACT: Rhizosphere microorganisms play an important role in the growth and health of plants. Around the world, diverse soil-borne pathogens attack Capsicum annuum causing significant damage and economic losses. This study determined whether the diversity and composition of microbial communities in the rhizosphere soil of C. annuum plants is significantly changed by wilt disease. We used the 16S rRNA gene for bacteria and the internal transcribed spacer region for fungi to characterize the rhizosphere microbiomes of healthy and wilted plants. The most abundant bacterial phyla were Proteobacteria and Gemmatimonadetes, while the most abundant fungal phyla were Ascomycota and Mucoromycota. The bacterial α-diversity did not show significant differences in richness and diversity, but did show a significant difference in evenness and dominance of species. Rare taxa were present in both healthy and wilted conditions with relative abundances < 1%. In the fungi, all evaluated estimators showed a significant reduction in the wilted condition. The β-diversity showed significant differences in the structure of bacterial and fungal communities, which were segregated according to plant health conditions. The same occurred when comparing the alpha and beta diversity of this study based on organic agriculture with that of other studies based on conventional agriculture. We observed a significant difference with estimators analyzed by segregating rhizosphere communities depending on the farming method used. Finally, the differential abundance analysis did not show significant results in the bacterial communities; however, in the fungal communities, Fusarium, Thanatephorus, Rhizopus, Curvularia, Cladosporium, and Alternaria were more abundant in the rhizosphere of wilted than healthy plants. Species from these genera have been previously reported as phytopathogens of several plants, including C. annuum.

Resumen Los humedales altoandinos son sistemas frágiles, vulnerables a la actividad humana y al cambio climático. La región de Arequipa (Perú) posee ecosistemas lóticos y lénticos altoandinos con impactos por la ganadería, piscicultura y represamiento. Se evaluó la comunidad de macroinvertebrados acuáticos de los humedales de Callalli-Oscollo y el posible efecto de las actividades humanas. Desde noviembre de 2017 a octubre de 2018 se realizaron muestreos en 4 estaciones en ambientes lóticos y 2 en lénticos. Los macroinvertebrados se identificaron a nivel de familia. Para evaluar la estructura comunitaria se registró la riqueza, la abundancia relativa, la diversidad de Shannon-Wiener, la dominancia de Simpson, la equidad de Pielou y la diversidad verdadera. Se aplicaron los índices ABI, BMWP/Bol y nPeBMWP para evaluar la calidad ecológica de los ambientes lóticos. En éstos se registraron 30 familias, siendo las más abundantes Chironomidae, Naididae, Limnesiidae, Elmidae, Baetidae y Lumbriculidae. La calidad ecológica fue buena, con excepción de la estación vinculada a la presa que fue dudosa. Los ambientes lénticos registraron 26 familias, siendo las más abundantes Cyprididae, Naididae y Corixidae. Las comunidades de macroinvertebrados en ambientes altoandinos reflejan el estado del ecosistema. Los ambientes vinculados con la actividad humana registran menor calidad ecológica.

Abstract High Andean wetlands are fragile systems, vulnerable to human activity and climate change. In the Arequipa region (Peru), there are high Andean lotic and lentic systems currently affected by livestock raising, fish farming, and dams. The aim of the study was to evaluate the aquatic invertebrate community in the Callalli-Oscollo wetlands and the possible impact of human activities. Samples were taken from November 2017 to October 2018 at 4 sampling stations in lotic environments and 2 in lentic environments. Macroinvertebrates were identified to the family level. The following were determined to evaluate community structure: richness, relative abundance, Shannon-Wiener diversity, Simpson dominance, Pielou evenness, and true diversity. The indices ABI, BMWP/Bol and nPeBMWP were applied to evaluate the ecological quality of the environments sampled. Thirty families were recorded in lotic environments, the most abundant being Chironomidae, Naididae, Limnesiidae, Elmidae, Baetidae and Lumbriculidae. The ecological quality was good, except at the station associated to the dam, where it was doubtful. Twenty-six families were recorded in lentic environments, the most abundant being Cyprididae, Naididae and Corixidae. The macroinvertebrate communities in high Andean environments reflect ecosystem conditions. Environments associated to human activity have lower ecological quality.

Abstract In this paper I propose a conceptual definition of USA’s hegemony. I used the analytical method from the Modern World-System perspective and the functioning of capitalism, where I argued that the hegemony of the United States must be understood as the continuous articulation between 1) the permanent accumulation of collective power (which implies that the media spreads the “universal” project of the hegemon; the protagonism in the creation and functioning of the spaces of articulation and; maintenance of the geographical expansion of capital and asymmetric exchange) and 2) the permanent exercise of domination (it implies the control of the monetary system; maintenance of accumulation by dispossession and the administration and application of multilateral and unilateral force) that enables and encourages the hegemonic power to direct the Modern World-System towards the maintenance and expansion of capitalism. However, this aim faces a process of relative hegemonic decline.

Resumen En este trabajo propongo una definición conceptual de la hegemonía de Estados Unidos. Para ello utilizo el método analítico situado en la perspectiva del sistema-mundo moderno y el funcionamiento del capitalismo, con lo cual argumento que la hegemonía de Estados Unidos debe entenderse como la articulación continua entre 1) la acumulación permanente del poder colectivo (en el que se implican la difusión mediática del proyecto “universal” del hegemón; protagonismo en la creación y el funcionamiento de los espacios de articulación; mantenimiento de la expansión geográfica de capital e intercambio asimétrico) y 2) el ejercicio permanente del dominio (en el que se implican el control del sistema monetario; el mantenimiento de la acumulación por despojo y la administración y aplicación de la fuerza multilateral y unilateral) que posibilita e impulsa a que la potencia hegemónica dirija el sistema-mundo moderno hacia el mantenimiento y la expansión del capitalismo, aunque este objetivo se enfrenta a un proceso de declive hegemónico relativo.

Abstract Protected natural areas seek the conservation of biodiversity. The objective of this study was to describe the tree species diversity and its ecological importance in the El Tecuan Ecological Park in Durango, Mexico. A systematic stratified sampling was carried out with 168 circular sites of 1 000 m2 each, distributed in 511.16 hectares of the Park, which means a sampling intensity of 3.2 %. At each site, all individuals with a greater or equal to 7.5 cm DBH were measured. The diversity of tree species was estimated with the Shannon index, while the ecological importance of the species was described with the parameters relative abundance based on the density or number of trees per hectare, relative dominance according to the basal area, relative frequency and the value of ecological importance (VIE). Results showed the presence of four genera: Arbutus (Ericaceae), Juniperus (Cupressaceae), Pinus (Pinacea) and Quercus (Fagacea). The Shannon index was 1.89, suggesting mid to high tree species diversity. The observed growing stock was 153.73 m3 ha-1 and the dominant diameter and height classes were 10 cm and 5 m, respectively. The Pinus genus had greater richness with nine species, of which P. cooperi recorded the highest density values (32.15 %), dominance (37.77 %) and of ecological importance (28.23 %), however, Quercus sideroxyla registered the highest relative frequency (18 %). The results here described will allow the development of sustainability actions for the conservation of tree species diversity in the study area.

Resumen El objetivo de las áreas naturales protegidas es la conservación de la biodiversidad. En el presente estudio se describe la diversidad de especies arbóreas y su importancia ecológica en el Parque Ecológico El Tecuán, Durango, México. Se realizó un muestreo sistemático estratificado con 168 sitios circulares de 1 000 m2, distribuidos en 511.16 hectáreas del Parque, con una intensidad de muestreo de 3.2 %. En cada sitio se midieron todos los individuos con diámetro normal superior o igual a 7.5 cm. La diversidad de especies arbórea se estimó con el Índice de Shannon, la importancia ecológica de las especies se describió con los parámetros abundancia relativa basada en la densidad o número de árboles por hectárea, dominancia relativa de acuerdo con el área basal, frecuencia relativa y el Valor de Importancia Ecológica (VIE). Los resultados mostraron la presencia de cuatro géneros: Arbutus (Ericaceae), Juniperus (Cupressaceae), Pinus (Pinacea) y Quercus (Fagacea). El Índice de Shannon fue de 1.89, que sugiere una diversidad arbórea de media a alta. Las existencias reales registradas fueron de 153.73 m3 ha-1 y las clases de diámetro y de altura dominantes de 10 cm y 5 m, respectivamente. El género Pinus tuvo la mayor riqueza de especies (nueve); de ellas, P. cooperi presentó los valores más altos de densidad (32.15 %), dominancia (37.77 %) y VIE (28.23 %); sin embargo, Quercus sideroxyla registró la mayor frecuencia relativa (18 %). Los resultados permitirán desarrollar acciones de sustentabilidad para la conservación de la diversidad arbórea del área de estudio.

Resumo Foi realizado o levantamento florístico e fitossociológico do componente epifítico vascular de um fragmento de Floresta Ombrófila Mista no município de Curitiba. Para amostragem fitossociológica, foram selecionados 20 forófitos, que foram divididos em 6 zonas ecológicas, sendo atribuídas notas referentes à dominância e à cobertura das espécies em cada zona. O valor de importância ecológica (VIE) foi calculado com base nos valores relativos de frequência, cobertura e dominância. Foram encontradas 80 espécies vasculares, 51 gêneros e 22 famílias. Orchidaceae foi a família de maior riqueza com 26 espécies (32,5%), seguida de Polypodiaceae com 12 (15%). Os gêneros mais ricos foram Acianthera com 6 espécies (7,5%) e Pleopeltis com 5 (6,3%) cada. No levantamento fitossociológico foram registradas 51 espécies e 17 famílias. O índice de Shannon (H’) estimado para a amostragem foi de 3,63 nats.ind-1 e a equidade (J’) foi 0,92. A maior parte das espécies (75%) são holoepífitos característicos, já os hemiepífitos e epífitas efêmeras foram pouco expressivos, com apenas 11,3% e 5%, respectivamente. As espécies com maior importância estrutural somaram 78,8% do VIE. Microgramma squamulosa e Lepismium warmingianum foram as mais importantes da comunidade, com VIE superior a 7% cada, já Campyloneurum nitidum foi a mais importante apenas na zona da base do fuste. Quatro famílias se destacaram: Polypodiaceae com VIE de 28,2%, Bromeliaceae com VIE 19,8%, Cactaceae com VIE 19,2% e Orchidaceae com VIE 17,3%, somando 84,6% do VIE. A maior parte dos registros ocorreu nas classes de cobertura 0-5 e 6- 10%, que somam 94,9% dos registros. Com relação à dominância, 87,1% dos registros de epífitas receberam nota 1 ou 2 (porte e biomassa reduzidos) e apenas 2,8% receberam nota 9 ou 15 (porte e biomassa expressivos) com destaque para Heptapleurum arboricola, espécie exótica invasora. Conclui-se que a comunidade epifítica apresentou elevada diversidade e riqueza, além de estrutura fitossociológica bem desenvolvida. A copa média e interna foram as zonas da árvore com maior diversidade e estrutura mais desenvolvida.

Abstract A survey of the floristic and phytosociological structure of the vascular epiphytic component a fragment of the Araucaria Rainforest in the municipality of Curitiba was carried out. For the phytosociological sampling, 20 phorophytes were selected, which were divided into 6 ecological zones, with scores referring to the dominance and coverage of the species in each zone. The value of ecological importance (VIE) was calculated based on the relative values of frequency, coverage and dominance. 80 vascular species, 51 genera and 22 families were found. Orchidaceae was the richest family with 26 species (32.5%), followed by Polypodiaceae with 12 (15%). The richest genera were Acianthera with 6 species (7.5%) and Pleopeltis with 5 ones (6.3%) each. In the structural analysis, 51 species and 17 families were registered. The Shannon index (H ') estimated for the sampling was 3.63 nats.ind-1 and the equity (J') was 0.92. Most species (75%) are characteristic holoepiphytes, while ephemeral hemiepiphytes and epiphytes were insignificant, with only 11.3% and 5%, respectively. The species with the greatest structural importance accounted for 78.8% of the VIE. Microgramma squamulosa and Lepismium warmingianum were the most important, with VIE greater than 7% each, Campyloneurum nitidum was the most important in the base of the shaft. Four families stood out: Polypodiaceae with VIE of 28.2%, Bromeliaceae with VIE 19.8%, Cactaceae with VIE 19.2% and Orchidaceae with VIE 17.3%, adding 84.6% of VIE. Most of the records occurred in the coverage classes 0-5 and 6- 10%, which account for 94.9% of the records. Regarding dominance, 87.1% of epiphyte records received a score of 1 or 2 (reduced size and biomass) and only 2.8% received a score of 9 or 15 (expressive size and biomass) with emphasis on Heptapleurum arboricola, an invasive exotic species. The middle canopy was the one with the greatest dominance, wealth and diversity. It is concluded that the epiphytic community showed high diversity and richness, in addition to a well-developed phytosociological structure. The middle and inner canopy were the areas of the tree with the greatest diversity and the most developed structure.

ABSTRACT Phytophthora infestans is the most important disease in potato crops. Its control is based on the use of chemical products that have developed pathogen resistance and high economic and environmental impacts. To reduce these effects, the use of plant varieties or cultivars resistant to this pathogen has been proposed. The aim of this study was to evaluate the heritability of resistance to this pathogen in a population of elite Solanum phureja genotypes. In this study, 1,355 clones with three replicates from 20 families were included in the evaluation. Heritability was assessed in the broad and narrow senses. Results of the relative area under the disease progress curve varied between 0.08 and 0.64, indicating that the population contains genes that code for resistance. Heritability in both directions (narrow 0.022 and broad 0.255) showed significant differences, indicating an influence of dominance genetic effects and environmental effects. Thus, to use these genotypes in potato breeding programs, hybridization methods should be used instead of selection methods.

Abstract An analysis was carried out to assess the effect, over a period of 10 years, of the application of the forestry selection method on diversity and structure in a temperate forest of the mountain range of the state of Durango, Mexico. Twelve Permanent Forest and Soil Research Sites (PFS and SRS) were compared and remeasured. The comparative analysis was performed using the Shannon-Wiener diversity index; the Importance Value index ―estimated by density, basal area, and species frequency at the sampling sites―, and three structure indexes for determining the species mixture, spatial distribution, and dominance of woodland. The Shannon-Wiener index did not exhibit significant statistical changes between the assessment periods when the Hutcheson t test was applied; the analysis showed that relative percentage values of abundance, dominance, and frequency, and the significance value index remained the same; structure indexes were not significantly modified in the 10-year interval after forest extraction; therefore, it was concluded that the forestry treatment applied does not modify the diversity or structure components of the tree stratum.

Resumen Se realizó un análisis para evaluar el efecto, en un periodo de 10 años, de la aplicación del Método Silvícola de Selección sobre la diversidad y estructura en un bosque templado de la Sierra de Durango, México. Se compararon doce Sitios Permanentes de Investigación Forestal y de Suelos (SPIFyS), los cuales fueron remedidos. El análisis comparativo se hizo mediante el índice de Diversidad de Shannon-Wiener; asimismo, se estimó el Índice de Valor de Importancia (IVI) mediante la densidad, el área basal y la frecuencia de las especies en los sitios de muestreo; también se calcularon tres índices de estructura para conocer la mezcla de especies, distribución espacial y dominancia del arbolado. El índice de Shannon-Wiener no evidenció cambios estadísticos significativos entre periodos de evaluación, cuando se aplicó la prueba de t de Hutcheson; el análisis mostró que los valores porcentuales relativos de abundancia, dominancia, frecuencia e Índice de Valor de Importancia se conservan. Los índices de estructura tampoco se modificaron significativamente en el intervalo de 10 años después de la extracción forestal, por lo que se determina que el tratamiento silvícola aplicado no modifica la diversidad ni los componentes de estructura del estrato arbóreo.