A catastrophic tropical drought kills hydraulically vulnerable tree species.

Drought-related tree mortality is now a widespread phenomenon predicted to increase in magnitude with climate change. However, the patterns of which species and trees are most vulnerable to drought, and the underlying mechanisms have remained elusive, in part due to the lack of relevant data and difficulty of predicting the location of catastrophic drought years in advance. We used long-term demographic records and extensive databases of functional traits and distribution patterns to understand the responses of 20 to 53 species to an extreme drought in a seasonally dry tropical forest in Costa Rica, which occurred during the 2015 El Niño Southern Oscillation event. Overall, species-specific mortality rates during the drought ranged from 0% to 34%, and varied little as a function of tree size. By contrast, hydraulic safety margins correlated well with probability of mortality among species, while morphological or leaf economics spectrum traits did not. This firmly suggests hydraulic traits as targets for future research

A second chromosomal copy of the catA gene endows Pseudomonas putida mt-2 with an enzymatic safety valve for excess of catechol.

Pseudomonas putida mt-2 harbours two different routes for catabolism of catechol, namely one meta pathway encoded by the xyl genes of the TOL plasmid pWW0 and one ortho pathway determined by the chromosomal ben and cat genes. P. putida mt-2 has a second chromosomal copy of the catA gene (named catA2) located downstream of the ben operon that encodes an additional catechol-1,2-dioxygenase. The metabolic and regulatory phenotypes of strains lacking one enzyme, the other and both of them in cells with and without the TOL plasmid were evaluated. The data consistently indicated that induction of the ortho pathway by benzoate plasmid-less strain P. putida KT2440 led to catechol surplus, the toxicity of which at high concentrations being counteracted by CatA2. Cells carrying pWW0 but lacking catA2 experienced both a rapid loss of the plasmid when grown on benzoate (a substrate of the lower pathway) and a slowdown of their growth rate when cultured with benzylalcohol (a substrate converted to benzoate by the upper pathway). These data reveal the role of CatA2 as a type of metabolic safety valve for excess catechol that alleviates the metabolic conflict generated by simultaneous expression of the meta and ortho pathways, thereby facilitating their co-existence

A second chromosomal copy of the catA gene endows Pseudomonas putida mt-2 with an enzymatic safety valve for excess of catechol.

Pseudomonas putida mt-2 harbours two different routes for catabolism of catechol, namely one meta pathway encoded by the xyl genes of the TOL plasmid pWW0 and one ortho pathway determined by the chromosomal ben and cat genes. P. putida mt-2 has a second chromosomal copy of the catA gene (named catA2) located downstream of the ben operon that encodes an additional catechol-1,2-dioxygenase. The metabolic and regulatory phenotypes of strains lacking one enzyme, the other and both of them in cells with and without the TOL plasmid were evaluated. The data consistently indicated that induction of the ortho pathway by benzoate plasmid-less strain P. putida KT2440 led to catechol surplus, the toxicity of which at high concentrations being counteracted by CatA2. Cells carrying pWW0 but lacking catA2 experienced both a rapid loss of the plasmid when grown on benzoate (a substrate of the lower pathway) and a slowdown of their growth rate when cultured with benzylalcohol (a substrate converted to benzoate by the upper pathway). These data reveal the role of CatA2 as a type of metabolic safety valve for excess catechol that alleviates the metabolic conflict generated by simultaneous expression of the meta and ortho pathways, thereby facilitating their co-existence

Cuentos que construyen paz

Esta propuesta se enmarca en el Proyecto Comunidades Educativas que Construyen Paz, del Instituto de Estudios Latinoamericanos (IDELA), cuyo propósito es facilitar procesos pedagógicos para la paz con comunidades educativas, por medio de una metodología lúdica y participativa, con el fin de promover la construcción de una cultura de paz en los espacios de convivencia cotidianos.Este libro es el resultado de un proceso que se fue tejiendo durante el 2021, el Festival para la Paz, el cual se realiza como una forma de contribuir a la creación y difusión de espacios participativos, lúdicos y creativos para instar a la paz desde las comunidades educativas. Esto, a modo de ir constituyendo una red con ideas novedosas que dan forma a dichos cuentos, constructores de paz. La creación y elaboración de cuentos fue una apuesta con equipos interdisciplinarios, niñas y niños de las escuelas públicas de la Regional de Heredia del Ministerio de Educación Pública de Costa Rica: Escuela Finca Guararí, Escuela Miguel Aguilar Bonilla, Escuela Rubén Darío y Escuela Santiago.This book is the result of a process that was woven during 2021, the Festival for Peace, which is carried out as a way to contribute to the creation and dissemination of participatory, playful and creative spaces to encourage peace from the educational communities. This, as a way of building a network with innovative ideas that give shape to these stories, peace builders. The creation and elaboration of stories was a bet with interdisciplinary teams, girls and boys of the public schools of the Heredia Regional of the Ministry of Public Education of Costa Rica: Finca Guararí School, Miguel Aguilar Bonilla School, Rubén Darío School and Santiago School.Instituto de Estudios Latinoamericano

Early Genomic, Epidemiological, and Clinical Description of the SARS-CoV-2 Omicron Variant in Mexico City

Omicron is the most mutated SARS-CoV-2 variant—a factor that can affect transmissibility, disease severity, and immune evasiveness. Its genomic surveillance is important in cities with millions of inhabitants and an economic center, such as Mexico City. Results. From 16 November to 31 December 2021, we observed an increase of 88% in Omicron prevalence in Mexico City. We explored the R346K substitution, prevalent in 42% of Omicron variants, known to be associated with immune escape by monoclonal antibodies. In a phylogenetic analysis, we found several independent exchanges between Mexico and the world, and there was an event followed by local transmission that gave rise to most of the Omicron diversity in Mexico City. A haplotype analysis revealed that there was no association between haplotype and vaccination status. Among the 66% of patients who have been vaccinated, no reported comorbidities were associated with Omicron; the presence of odynophagia and the absence of dysgeusia were significant predictor symptoms for Omicron, and the RT-qPCR Ct values were lower for Omicron. Conclusions. Genomic surveillance is key to detecting the emergence and spread of SARS-CoV-2 variants in a timely manner, even weeks before the onset of an infection wave, and can inform public health decisions and detect the spread of any mutation that may affect therapeutic efficacy

Genetic analysis of the dry forest timber tree Sideroxylon capiri in Costa Rica using AFLP

Sideroxylon capiri (“Tempisque”) is a threatened and economically important timber species in the dry forest of Costa Rica. To assess the extent of the genetic diversity between and within populations of this species, 86 samples were obtained from four sites in the northwestern part of the country from protected and non-protected areas. They were analyzed by amplified fragment length polymorphism. Five primers were used to generate 254 polymorphic bands. Molecular variance indicated a 92 % within locations with a PhiPT (φ st) of 0.083 and a He from 0.204 to 0.249. PCoA analysis showed two different groups: one formed by Palo Verde and La Cruz samples, and another group with Nicoya and Barra Honda samples. The dendrogram arranged the samples in three groups: individuals from Palo Verde and La Cruz divided in two groups, and a more compact group from Barra Honda and Nicoya. A positive correlation between pairwise linearized geographical distance and genetic differentiation among populations was detected by Mantel test (R 2 = 0.76241, P = 0.04). Results are discussed in terms of fragmentation of the continuous forests and geographical barriers. Despite these results, it is evident that a great genetic diversity exists for this species and the results can be used for conservation purposes.Universidad de Costa Rica/[]/UCR/Costa RicaConsejo Nacional para Investigaciones Científicas y Tecnológicas/[]/CONICIT/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí