Protected land enhances the survival of native aquatic macrophytes and limits invasive species spread in the Panama Canal

1. This study examined whether protected land in a tropical reservoir's catchment can promote the survival of native aquatic plants (macrophytes) and limit the spread of invasive alien plant species (macrophyte IAS), which can threaten native wildlife and require expensive remediation. As the number of tropical river dams is expected to increase in the coming decades to meet societal demands, it is crucial to explore solutions for preserving aquatic biodiversity. 2. The study used a before–after–control–intervention design, based on monitoring data and long-term sedimentological, climatic and ecological records from both lake and river zones adjacent to protected and unprotected lands around the 100-year-old Gatun Lake in the Panama Canal, Panama. The research examined the impact of impoundment and the invasion of Pontederia crassipes (water hyacinth) and Hydrilla verticillata (water thyme) on native macrophyte communities and environmental variables. 3. Lake zones adjacent to protected lands had lower nutrient concentrations, greater variations in water depth profiles and reduced fluctuations in water chemistry than lake zones outside areas of land protection. In addition, the results showed that whereas zones adjacent to unprotected land became dominated by macrophyte IAS, lake zones adjacent to protected areas were more resilient to the spread of macrophyte IAS and were able to maintain viable populations of native pre-dam species for >100 years. 4. This study indicates that protecting land adjacent to tropical reservoirs could be a cost-effective solution for preserving aquatic macrophyte biodiversity by retaining nutrients, stabilizing water chemistry, providing habitat heterogeneity and protecting native vegetation, while still supporting terrestrial conservation goals. These findings could aid in planning measures for the hundreds of proposed dam projects across lowland tropical areas and provide new insights into best practices for enhancing river ecosystem resilience

La dimensión comunicativa de los objetos: imaginarios y sistemas simbólicos como mediadores del recuerdo en la cultura material

An investigation is presented on the imaginary relations between the inhabitants of the Oriente Antioqueño region, in Colombia, and their favorite objects, broken down into three generations: children, parents and grandparents. It is based on a philosophical, anthropological and semiotic reflection of the objects, where the classical conceptual frameworks in the matter are reviewed and put in dialogue with contemporary works of sociological, communicative and aesthetic nature. A mixed methodology is used: first, from the quantitative analysis variables are defined as generation, environment, time with the object and symbolic system; second, the generations and the environment of origin of objects are correlated with the symbolic systems in which they act. At the end, we reflect on the relevance and topicality of the theoretical traditions of object study to look at the implications of the supposed virtualization/digitization of the world in relation to what the empirical results of the study show.Se presenta una investigación sobre las relaciones imaginarias entre los habitantes de la región Oriente Antioqueño, en Colombia, y sus objetos favoritos, desglosados en tres generaciones: hijos, padres y abuelos. Se parte de una reflexión filosófica, antropológica y semiótica de los objetos, donde se revisan los marcos conceptuales clásicos en la materia y se les pone en diálogo con trabajos contemporáneos de corte sociológico, comunicativo y estético. Se emplea una metodología mixta: primero, desde lo cuantitativo se definen variables de análisis como generación, entorno, tiempo con el objeto y sistema simbólico; en segunda instancia, se correlacionan las generaciones y el entorno de proveniencia de los objetos con los sistemas simbólicos en los cuales estos actúan. Al final se reflexiona sobre la pertinencia y actualidad de las tradiciones teóricas de estudio de los objetos para mirar las implicaciones de la supuesta virtualización/digitalización del mundo en relación con lo que muestran los resultados empíricos del estudio

El diálogo de saberes como estrategia metodológica para la articulación de investigación y extensión: la experiencia del Programa Fals Borda en el IDAES

Es claro que las universidades públicas, especialmente en América Latina, tienen como función principal la educación y –dentro de lo posible– la investigación. Ahora bien, ¿qué entendemos por extensión cuando la consideramos otra de sus funciones sustanciales y qué implica su realización? ¿Se extiende qué, hacia quiénes, hacia dónde y por qué? Si nos remontamos a sus orígenes a fines del siglo XIX e inicios del XX, esta noción surge como una política de acercamiento de las universidades hacia la sociedad que la circunda, como una forma de incluir en el mundo académico a aquellos que normalmente están excluidos de él. El “extensionismo” (que es el resultante movimiento humanista) buscaba democratizar la cultura, la ciencia y la tecnología que en su seno se producía y circulaba, para ponerla al servicio del “pueblo” (Jiménez Leyva, 2003). Estas ideas fundaron un tipo de política universitaria presente en gran parte de las universidades latinoamericanas, y cuestionada desde la década del 70.Fil: Gavazzo, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; ArgentinaFil: Espina, Rosario. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; ArgentinaFil: Arango, Catalina. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; ArgentinaFil: González, Sabrina. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; ArgentinaFil: Canuto, María Dolores. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; Argentin

Infección de Spongospora subterranea en Esquejes de Papa (Solanum tuberosum) Var. Diacol Capiro Proveniente de Tres Fuentes de Inóculo

La sarna polvosa causada por Spongospora subterranea (Wallroth) Lagerheim f. sp. subterranea Tomlinson es una enfermedad que disminuye los rendimientos y la calidad de tubérculos de papa. Es un parásito obligado el cual por sus características biológicas y reproductivas, posee una gran capacidad de sobrevivencia e infección no solo en su principal hospedero, sino también en diversas especies silvestres. Este patógeno es un protozoario, su infección ocurre por medio de zoosporas las cuales se liberan a partir de quistosoros y son el principal modo de dispersión de la enfermedad. Estos pueden encontrarse en tubérculos, raíces y en el suelo, donde permanecen como estructuras de resistencia por varios años, hasta que las condiciones ambientales favorecen la liberación de zoosporas, para dar inicio a nuevas infecciones. En el presente estudio se evaluó un método de bioensayo con el fin de establecer bajo condiciones controladas, la infección de quistosoros de Spongospora subterranea provenientes de suelo, raíz y de tubérculo, en la variedad comercial de papa Diacol Capiro, con el fin de determinar la fuente más infectiva. Las plantas fueron inoculadas con una solución que contenía una concentración de 1x104 quistosoros/mL en condiciones de casa de malla. Las evaluaciones fueron realizadas a los 15 días después de ser inoculadas, en floración y tuberización. Los resultados mostraron diferencias significativas en las fuentes de inóculo empleadas, manifestándose mayor incidencia de Spongospora subterranea en las plantas inoculadas con quistosoros provenientes de tubérculo

Identification of Candida species colonizing the lower respiratory tract in patients with respiratory symptoms

ABSTRACT: Colonization of the lower respiratory tract by Candida spp., is considered a prerequisite for the development of Candida infection in patients with risk factors. OBJECTIVE To determine the different Candida species colonizing the lower respiratory tract in patients with respiratory symptoms by bronchoalveolar lavages (BAL) assessment. MATERIALS AND METHODS We conducted a descriptive study, which analyzed 61 BAL samples from patients with respiratory symptoms. BAL samples were cultured on selective media including CHROMagar Candida™, tobacco agar and hypertonic Sabouraud agar; and identification was also performed by sugar assimilation method API 20C AUX®. Additionally, we determined the minimal inhibitory concentration (MIC) for fluconazole and voriconazole. RESULTS In 61 patients studied, we observed that 26 (42.6%) of them were colonized according to the following distribution: C. albicans (36.1%.), C. tropicalis (8.2%), C. krusei (3.3%), C. glabrata (3.3%), C. dubliniensis (4.9%), C. lusitaniae (1.6%) and other Candida species (6.6%). In addition, we found that some patients were colonized by more than one Candida species. Candida krusei and C. glabrata showed a diminished susceptibility or resistance to azoles, whereas C. albicans was 100% sensitive to these antifungals. CONCLUSIONS These results indicate that the frequency of the Candida spp., isolates in BAL from patients with respiratory symptoms is higher than that reported in other studies.RESUMEN: La sobrecolonización del tracto respiratorio inferior por levaduras del género Candida se considera una condición necesaria para el desarrollo de la infección candidiásica en pacientes con factores de riesgo. OBJETIVO Determinar las diferentes especies de Candida que colonizan el tracto respiratorio inferior en pacientes sintomáticos respiratorios, mediante el estudio del lavado broncoalveolar. MATERIALES Y MÉTODOS Se realizó un estudio descriptivo, en el que se analizaron 61 muestras de lavados broncoalveolares (LBA) provenientes de pacientes sintomáticos respiratorios. Las muestras se cultivaron en medios selectivos que inclueyron el CHROMagar Candida™, agar tabaco y agar Sabouraud hipertónico; y se realizó identificación por medio de la técnica de asimilación de azúcares API 20C AUX®. Adicionalmente, se determinó la concentración inhibitoria mínima (CIM) para el fluconazol y voriconazol. voriconazol. RESULTADOS En 61 pacientes estudiados se observó que 26 de ellos (42.6%) estaban colonizados por una o mas especies de Candida de acuerdo con la siguiente distribución: C. albicans (36.1%.), C. tropicalis (8.2%), C. krusei (3.3%), C. glabrata (3.3%), C. dubliniensis (4.9%), C. lusitaniae (1.6%) y otras especies de Candida (6.6%). Adicionalmente, se anotó que algunos de los pacientes estaban colonizados por más de una especie de Candida. C. krusei y C. glabrata presentaron sensibilidad disminuida o resistencia a los azoles, mientras que C. albicans fue 100% sensible a estos antifúngicos. CONCLUSIÓN Los resultados indican que la frecuencia de aislamientos de Candida spp., a partir de lavado broncoalveolar es mayor a lo reportado en otros estudios

Impactos socioeconómicos de la agroindustria de la palma de aceite en Colombia :

Palma-Elaeis guineensi

Causes and consequences of recent degradation of the Magdalena River basin, Colombia

The Magdalena River in Colombia is one of the world's largest (discharge = 7100 m3 s−1) tropical rivers, hosting > 170 aquatic vertebrate species. However, concise synthesis of the current ecological and environmental status is lacking. By documenting the anthropogenic stressors impacting the river on time scales ranging from centuries to decades, we found that the river system is subject to the compounding impacts of climate change, river impoundment, invasive alien species (IAS), catchment deforestation, and water pollution. We show that the Magdalena is a woefully understudied ecosystem relative to its critical importance to Colombia's economy, culture, and biodiversity compared with other similarly sized tropical rivers. We emphasize the need for research on (1) IAS population and ecological dynamics, (2) river damming and its links with IAS and climate change, and (3) land-use changes as well as identifying sources of water pollution and strategies for mitigation

Tocilizumab in giant cell arteritis. Observational, open-label multicenter study of 134 patients in clinical practice

OBJECTIVE: Tocilizumab (TCZ) has shown efficacy in clinical trials on giant cell arteritis (GCA). Real-world data are scarce. Our objective was to assess efficacy and safety of TCZ in unselected patients with GCA in clinical practice Methods: Observational, open-label multicenter study from 40 national referral centers of GCA patients treated with TCZ due to inefficacy or adverse events of previous therapy. Outcomes variables were improvement of clinical features, acute phase reactants, glucocorticoid-sparing effect, prolonged remission and relapses. A comparative study was performed: (a) TCZ route (SC vs. IV); (b) GCA duration (?6 vs. >6 months); (c) serious infections (with or without); (d) ?15 vs. >15 mg/day at TCZ onset. RESULTS: 134 patients; mean age, 73.0 ± 8.8 years. TCZ was started after a median [IQR] time from GCA diagnosis of 13.5 [5.0-33.5] months. Ninety-eight (73.1%) patients had received immunosuppressive agents. After 1 month of TCZ 93.9% experienced clinical improvement. Reduction of CRP from 1.7 [0.4-3.2] to 0.11 [0.05-0.5] mg/dL (p < 0.0001), ESR from 33 [14.5-61] to 6 [2-12] mm/1st hour (p < 0.0001) and decrease in patients with anemia from 16.4% to 3.8% (p < 0.0001) were observed. Regardless of administration route or disease duration, clinical improvement leading to remission at 6, 12, 18, 24 months was observed in 55.5%, 70.4%, 69.2% and 90% of patients. Most relevant adverse side-effect was serious infections (10.6/100 patients-year), associated with higher doses of prednisone during the first three months of therapy. CONCLUSION: In clinical practice, TCZ yields a rapid and maintained improvement of refractory GCA. Serious infections appear to be higher than in clinical trials

Long-Term Habitat Degradation Drives Neotropical Macrophyte Species Loss While Assisting the Spread of Invasive Plant Species

The spread of invasive macrophyte species is a pressing threat to neotropical shallow lakes. Yet there are few studies addressing the full extent of biotic and abiotic changes that may occur in response to invasive species. Less is known of how other human-induced stressors such as eutrophication and lake draining may interact over time with invasive macrophytes to influence biodiversity. We combined limnological observations with paleoecological data from Fúquene Lake, Colombia, a eutrophic neotropical shallow lake, to provide information on the current and long-term (decades-centuries) dynamics of the spread of two well-established invasive plants Eichhornia crassipes and Egeria densa. We found a unique in macrophyte species composition in areas currently dominated by Egeria and Eichhornia. Eichhornia-dominated areas had 14 macrophyte species, turbid (secchi=19 ± 6 cm) and poorly oxygenated (3.94 ± 2.61 ppm) waters whereas Egeria-rich areas supported 5 species and had clearer (secchi=51 ± 12 cm) and better-oxygenated (6.06 ± 2.4 ppm) waters. Historical macrophyte community shifts were linked to eutrophication and lake level variation and characterized by the loss of charophytes and bryophytes before 1500 CE and subsequent reductions in Nymphaea sp., Potamogeton illinoensis and Najas guadalupensis in the early 1900s (lake draining). Eichhornia crassipes (since 1500 CE) and E. densa (early 1900s) occurred well before proposed dates of introduction (1950s and 1990 respectively). Both species have rapidly expanded since the 1990s along with Azolla filiculoides in response to an inflow water diversion scheme and heavy nutrient loads. Our results suggest that the spread of Eichhornia and Egeria was not responsible for native macrophyte species loss, but that their current dominance is exerting synergistic and antagonistic secondary effects on plant assemblages through habitat modification, competitive exclusion and promotion of habitat heterogeneity across the lake. It could therefore be misleading to suggest that invasive plants causes macrophyte species loss in degraded lakes. We suggest that aggressive species like Eichhornia, Azolla, and Egeria require hydrologically stable and eutrophic environments to spread; thus, management actions should focus on controlling these two factors. Our study demonstrates the need to use a long-term approach to fully-understand the effects of invasive macrophytes