Dinoflagellate abundance in the Laguna Botos, Poás Volcano, Costa Rica

Phytoplankton of the Botos lagoon of Poás volcano is dominated by dinoflagellates. The two species of greatest abundance in March 1979 were Peridinium incospicuum Lemm. and P. volzii Lemm, which represented 96% of total cells. The identity of these species was confirmed by electron microscopy. Both species are cosmopolitan. Without further resealch it is premature to compare Botos Lagoon with similar lakes in Central America

Genetic mapping of semi-polar metabolites in pepper fruits (Capsicum sp.): towards unravelling the molecular regulation of flavonoid quantitative trait loci

Untargeted LCMS profiling of semi-polar metabolites followed by metabolite quantitative trait locus (mQTL) analysis was performed in ripe pepper fruits of 113 F2 plants derived from a cross between Capsicum annuum AC1979 (no. 19) and Capsicum chinense No. 4661 Selection (no. 18). The parental accessions were selected based on their variation in fruit morphological characteristics and fruit content of some target phytonutrients. Clear segregation of fruit colour and fruit metabolite profiles was observed in the F2 population. The F2 plants formed three clusters based on their metabolite profiles. Of the total of 542 metabolites, 52 could be annotated, including a range of flavonoids, such as flavone C-glycosides, flavonol O-glycosides and naringenin chalcone, as well as several phenylpropanoids, a capsaicin analogue, fatty acid derivatives and amino acid derivatives. Interval mapping revealed 279 mQTLs in total. Two mQTL hotspots were found on chromosome 9. These two chromosomal regions regulated the relative levels of 35 and 103 metabolites, respectively. Analysis also revealed an mQTL for a capsaicin analogue, located on chromosome 7. Confirmation of flavonoid mQTLs using a set of six flavonoid candidate gene markers and their corresponding expression data (expression QTLs) indicated the Ca-MYB12 transcription factor gene on chromosome 1 and the gene encoding flavone synthase (FS-2) on chromosome 6 as likely causative genes determining the variation in naringenin chalcone and flavone C-glycosides, respectively, in this population. The combination of large-scale metabolite profiling and QTL analysis provided valuable insight into the genomic regions and genes important for the production of (secondary) metabolites in pepper fruit. This will impact breeding strategies aimed at optimising the content of specific metabolites in pepper frui

The social relations of health care and household resource allocation in neoliberal Nicaragua

<p>Abstract</p> <p>Background</p> <p>With the transition to neoliberalism, Nicaragua's once-critically acclaimed health care services have substantially diminished. Local level social formations have been under pressure to try to bridge gaps as the state's role in the provision of health care and other vital social services has decreased. This paper presents a case study of how global and national health policies reverberated in the social relations of an extended network of female kin in a rural community during late 2002 - 2003.</p> <p>Methods</p> <p>The qualitative methods used in this ethnographic study included semi-structured interviews completed during bi-weekly visits to 51 households, background interviews with 20 lay and professional health practitioners working in the public and private sectors, and participant-observation conducted in the region's government health centers. Interviews and observational field notes were manually coded and iteratively reviewed to identify and conceptually organize emergent themes. Three households of extended kin were selected from the larger sample to examine as a case study.</p> <p>Results</p> <p>The ongoing erosion of vital services formerly provided by the public sector generated considerable frustration and tension among households, networks of extended kin, and neighbors. As resource allocations for health care seeking and other needs were negotiated within and across households, longstanding ideals of reciprocal exchange persisted, but in conditions of poverty, expectations were often unfulfilled, exposing the tension between the need for social support, versus the increasingly oppositional positioning of social network members as sources of competition for limited resources.</p> <p>Conclusions</p> <p>In compliance with neoliberal structural adjustment policies mandated by multilateral and bilateral agencies, government-provided health care services have been severely restricted in Nicaragua. As the national safety net for health care has been eroded, the viability of local level social formations and their ability to respond to struggles collectively has been put at risk as well. Bi-lateral and multilateral agencies need to take into account local needs and demands, and implement policies in a manner that respects national laws, and protects both the physical and social well-being of individuals.</p

Yields of eddo (Colocasia esculenta) and maize (Zea mays) in association with Erythrina fusca y fusca and Calliandra calothyrsus in an alley farming system

3 ilus. 1 tab. 9 ref. 6 pág.Se evaluó la producción de maíz (Zea mays L.) y ñampí (Colocasia esculenta L.), con un ciclo por año de cada uno, en un cultivo en callejones con Calliandra caloathyrsus y Erythrina fusca (2podas/año) establecidos a 6 m por 0.5, 1 y 2 m. en el ñampí se evaluaron el peso y número de los cormelidos comerciales y totales en maíz el peso seco del grano y la biomasa vegetativa y en los árboles la biomasa de las podas. En maíz y ñampí, a partir de la segunda cosecha, se observó la superioridad del asocio con árboles versus el monocultivo. En maíz en la tercera cosecha, E. fusca fue superior que C. calothyrsus. Se concluye que ñampí tiene potencial para ser cultivado en asociación con árboles. Sin embargo, la biomasa de los árboles no satisface los requerimientos nutricionales del cultivo. Production of maize (Zea mays L.) and eddo (Colocasia esculenta L.), one harvest of each crop per year, were evaluated in an alley farming system with Calliandra calothyrsus and Erythrina fusca, planted in rows 6m wide with spacings of 0.5, 1 and 2m between trees and pruned twice yearly. For eddoes and maize, weight and number of commercial and total corns were evaluated for maize, dry weight of harvested grain, and for the trees, biomass production. For eddoes and maize, starting at second harvest, yields in alley farming were greater than in monoculture in the third harvest, maize yields were greater with E. fusca than with C. calothyrsus. It was concluded that there is potential to cultivate eddoes in association with trees although biomass production was insufficient to meet nutrient needs

Morphology and characteristics of eight Oxisols in contrasting landscapes of Costa Rica

Oxisols have been previously reported in Costa Rica. However, few studies provided specific data to corroborate their presence and explain their genesis under different soil-forming factors. This study was performed with the aim to confirm Oxisols occurrence in different landscapes and parent materials in Costa Rica. Eight pedons were sampled, described, characterized, and classified according to Soil Taxonomy in five landscapes. All pedons studied presented clay contents above 40% in surface horizons. Subsurface horizons presented red colors, high contents of low-activity clay minerals with cation exchange capacity values at pH 7 (CEC7) less than 16 cmolc kg−1 clay and less than 9.6% weatherable minerals in the sand fraction. The suborders Ustox, Udox and Perox were identified. Among the Ustox, three contrasting subgroups were identified: Kandiustalfic Eustrustox, Plinthic Kandiustox, and Anionic Acrustox. Conversely, soils classified into the suborder Udox presented the same great group: Kandiudox; with three subgroups identified: Typic Kandiudox, Plinthic Kandiudox, and Rhodic Kandiudox. In addition, one pedon was classified into the suborder Perox, with the subgroup Andic Haploperox. The diversity in geologic materials (basaltic, pyroclastic, and sedimentary rocks), geomorphology (mountains, plains, dissected volcanic cones, and Quaternary alluvial fans), and the climatic conditions (total annual rainfall ranged from 1853 to 5780 mm year−1) observed in the studied areas made possible the diverse taxonomic classification for the eight Oxisols. Results obtained confirmed occurrence of Oxisols in Costa Rica and verify soil classification from previous literature reports. Our findings in soil genesis and forming factors enhance the knowledge in pedogenesis and properties of advanced weathering stage soils in Central America.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigaciones Agronómicas (CIA

Chlorophyll fluorescence imaging reveals genetic variation and loci for a photosynthetic trait in diploid potato

Physiology and genetics are tightly interrelated. Understanding the genetic basis of a physiological trait such as the quantum yield of the photosystem II, or photosynthetic responses to environmental changes will benefit the understanding of these processes. By means of chlorophyll fluorescence (CF) imaging, the quantum yield of photosystem II can be determined rapidly, precisely and non-invasively. In this article, the genetic control and variation in the steady-state quantum yield of PSII (ΦPSII) is analyzed for diploid potato plants. Current progress in potato research and breeding is slow due to high levels of heterozygosity and complexity of tetraploid genetics. Diploid potatoes offer the possibility of overcoming this problem and advance research for one of the globally most important staple foods. With the help of a diploid genetic mapping population two genetic loci that were strongly associated with differences in ΦPSII were identified. This is a proof of principle that genetic analysis for ΦPSII can be done on potato. The effects of three different stress conditions that are important in potato cultivation were also tested: salt stress, low temperature and deficiency in the macronutrient phosphate. For the last two stresses, significant decreases in photosynthetic activity could be shown, revealing potential for stress detection with CF based tools. In general, our findings show the potential of high-throughput phenotyping for physiological research and breeding in potato.</p

CARACTERIZACIÓN FLORÍSTICA Y ESTRUCTURAL DE UNA PARCELA DE BOSQUE SEMICADUCIFOLIO EN EL PARQUE NACIONAL SOBERANÍA, PANAMÁ

This work has characterized tree species composition and horizontal structure (HS) of a semideciduous forest plot in the final stretch of the "Espiritu del Bosque" trail, Soberania National Park. For this purpose, we delimited a 1 ha plot, which in turn was subdivided into 10 equal sized subplots (20 x 50 m).&nbsp; We measured and identified all trees with DBH ≥ 10 cm and calculated the Importance Value Index (IVI) of tree species to determine HS. On average for each subplot were found 48 individuals and 22 species. A total of 480 individuals were registered, distributed in 78 species, 59 genera and 29 families, being the family Arecaceae (22%) the most abundant, while Fabaceae family with 10 species had the highest wealth. Anacardium excelsum species registered the highest IVI value (18%), indicating that it has a great ecological importance within the studied area.Se determinó la composición florística arbórea, así como la estructura horizontal (EH) de una parcela de bosque semicaducifolio en el tramo final del sendero “Espíritu del Bosque”, Parque Nacional Soberanía, Panamá.&nbsp; Para ello, se delimitó una parcela de 1 ha, la cual a su vez se subdividió en 10 subparcelas de igual tamaño (20 x 50 m). Se midieron e identificaron todos los árboles con un DAP ≥ 10 cm y se calculó el índice de valor de importancia (IVI) de las especies arbóreas, para determinar la EH.&nbsp; En promedio por cada subparcela se encontraron 48 individuos y 22 especies. Se registraron en total 480 individuos distribuidos en 78 especies, 59 géneros y 29 familias, siendo la familia Arecaceae (22%) la más abundante, mientras que la familia Fabaceae con 10 especies, presentó la mayor diversidad. El Coeficiente de Mezcla de las especies es de 0.16.&nbsp; La especie Anacardium excelsum registró el mayor valor de IVI (18%), lo cual indica que tiene una gran importancia ecológica dentro del área de estudio. &nbsp