Reproductive phenology of Pouteria splendens (Sapotaceae)

Indexación: Web of Science; ScieloPouteria splendens (A.DC.) Kuntze (lúcumo silvestre, palo colorado) es un arbusto endémico con problemas de conservación de Chile central. Es la única especie representante de la familia Sapotaceae en el país y se conoce muy poco de su ciclo de vida. Se estudió su fenología reproductiva durante la primavera y verano, desde septiembre 2007 hasta abril 2008, en la población remanente más grande, localizada en Los Molles (V Región de Valparaíso). Se encontró un incremento en la producción de yemas florales, flores y frutos desde septiembre a febrero, decayendo en marzo. Al igual que en otras especies de ambientes mediterráneos, el máximo en la formación de botones florales, flores y frutos ocurrió en época de verano, durante febrero. También detectamos una alta sincronía en la fenología entre los individuos en la población estudiada. PALABRAS CLAVE: Planta amenazada, floración, fructificación, lúcumo silvestre.Pouteria splendens (A.DC.) Kuntze (lúcumo silvestre, palo colorado) is an endemic and in dangered tree from Central Chile. It's the only member of the Sapotaceae family in the country and little is known about his life cycle. We studied the reproductive phenology during Spring and Summer, from September 2007 to April 2008, on the biggest remained population of P. splendens, located in Los Molles (V Región Valparaíso). We recorded an increase in the production of flower buds, flowers and fruits from September to February, decaying in March. According with other species from Mediterranean environments, the peak of flower buds, flowers and fruits was recorded during Summer, in February. We also detected a high synchrony in the phenology among the individuals within the population. KEYWORDS: Endangered plant, flowering, fructification, lúcumo silvestre.http://ref.scielo.org/k9sbc

Seedling distribution and seed germination of chilean lucumo (Pouteria splendens) in Los Molles, Chile

Indexación: Web of Science; Scielo.Pouteria splendens (lúcumo chileno, palo colorado) es un árbol endémico de Chile central con problemas de conservación. Es la única especie representante de la familia Sapotaceae en el país y se conoce muy poco de su ciclo de vida. En este trabajo describimos el patrón de distribución espacial de plántulas en la población remanente de mayor tamaño de la especie, e investigamos el efecto de la disponibilidad de agua, la presencia de pericarpo en las semillas y de la hojarasca en la capacidad de germinación. La densidad de plántulas fue mayor bajo el dosel de las plantas madres, que fuera de estas. Solo la disponibilidad de agua tuvo un efecto significativo sobre la germinación. La especie tiene el potencial de regenerar, en futuros planes de conservación y restauración de la especie hay que aprovechar el efecto nodriza que estaría ejerciendo el dosel.Pouteria splendens (Chilean lucumo, red wood) is an endemic and endangered tree from Central Chile. It is the only member of the Sapotaceae family in the country and little is known about his life cycle. In this work we described the spatial distribution of seedlings in the biggest remained population of the species, and we investigated the effect of the water availability, presence of pericarp in the seeds and the leaf litter on the capacity of germination in the species. Seedling density was higher under the canopy of mother plants, than outside its. Only water availability had a significant effect on the germination. The species has the potential to regenerate, in future plans of conservation and restoration of the species must take advantage the nurse effect of the canopy.http://ref.scielo.org/wt65f

SRL pathogenicity island contributes to the metabolism of D-aspartate via an aspartate racemase in Shigella flexneri YSH6000

In recent years, multidrug resistance of Shigella strains associated with genetic elements like pathogenicity islands, have become a public health problem. The Shigella resistance locus pathogenicity island (SRL PAI) of S. flexneri 2a harbors a 16Kbp region that contributes to the multidrug resistance phenotype. However, there is not much information about other functions such as metabolic, physiologic or ecological ones. For that, wild type S. flexneri YSH6000 strain, and its spontaneous SRL PAI mutant, 1363, were used to study the contribution of the island in different growth conditions. Interestingly, when both strains were compared by the Phenotype Microarrays, the ability to metabolize D-aspartic acid as a carbon source was detected in the wild type strain but not in the mutant. When D-aspartate was added to minimal medium with other carbon sources such as mannose or mannitol, the SRL PAI-positive strain was able to metabolize it, while the SRL PAI-negative strain did not. In order to identify the genetic elements responsible for this phenotype, a bioinformatic analysis was performed and two genes belonging to SRL PAI were found: orf8, coding for a putative aspartate racemase, and orf9, coding for a transporter. Thus, it was possible to measure, by an indirect analysis of racemization activity in minimal medium supplemented only with D-aspartate, that YSH6000 strain was able to transform the D-form into L-, while the mutant was impaired to do it. When the orf8-orf9 region from SRL island was transformed into S. flexneri and S. sonnei SRL PAI-negative strains, the phenotype was restored. Also, when single genes were cloned into plasmids, no complementation was observed. Our results strongly suggest that the aspartate racemase and the transporter encoded in the SRL pathogenicity island are important for bacterial survival in environments rich in D-aspartate

Epigenetic control of the EWS-FLI1 promoter in Ewing's sarcoma

Q2Q1Ewing sarcoma (ES) is a primary bone marrow tumor that very rarely develops in extra-osseous tissues, such as lung. The hallmark of ES tumors is a translocation between chromosomes 11 and 22, resulting in a fusion protein, commonly referred to as EWS-FLI1. The epigenetic profile (histone acetylation and methylation enrichment of the promoter region) that may regulate the expression of the aberrant transcription factor EWS-FLI1, remains poorly studied and understood. Knowledge of epigenetic patterns associated with covalent histone modification and expression of enzymes associated with this process, can contribute to the understanding of the molecular basis of the disease, as well as to the identification of possible molecular targets involved in expression of the EWS-FLI1 gene, so that therapeutic strategies may be improved in the future. In the present study, the transcriptional activation and repression of the EWS-FLI1 fusion gene in ES was accompanied by selective deposition of histone markers on its promoter. The EWS-FLI1 fusion gene was evaluated in two patients with ES using conventional cytogenetic, fluorescence in situ hybridization and nested PCR assays, which revealed that the aberrant expression of the EWS-FLI1 gene is accompanied by enrichment of H3K4Me3, H3K9ac and H3K27ac at the promoter region.N/

Effectiveness of disinfectant treatments for inactivating Piscirickettsia salmonis

This short communication investigated in vitro differences between commercial disinfectants types (n = 36), doses of application, and time of action in the elimination of Piscirickettsia salmonis, the most important bacterium affecting farmed salmon in Chile. Seven different treatments were examined, including active and inactive chlorine dioxides, glutaraldehyde, hypochlorite disinfectants and detergents, peracetic acid, peroxides and other miscellaneous methods A 3 replicate set of each of the sample groups was stored at 20 °C and 95% relative humidity and retested after 1, 5 and 30 min with varying doses (low, recommended and high doses). Multiple comparison tests were performed for the mean log CFU/ml among different disinfectant types, dose (ppm) and time of exposure (minutes) on the reduction of P. salmonis. Overall, disinfection using peracetic acid, peroxides, and both active and inactive chlorine dioxides caused significantly higher reduction of >7.5 log CFU/ml in samples, compared to other tested sanitizers. The lowest reduction was obtained after disinfection with hypochlorite detergents. As expected, as doses and time of action increase, there was a significant reduction of the overall counts of P. salmonis. However, at lowest doses, only use of paracetic acids resulted in zero counts. Implementation of effective protocols, making use of adequate disinfectants, may enhance biosecurity, and ultimately, mitigate the impact of P. salmonis in farmed salmon

Effect of zinc intake on growth in infants: A meta-analysis

A systematic review and meta-analysis of available randomized controlled trials (RCTs) was conducted to evaluate the effect of zinc (Zn) intake on growth in infants. Out of 5500 studies identified through electronic searches and reference lists, 19 RCTs were selected after applying the exclusion/inclusion criteria. The influence of Zn intake on growth was considered in the overall meta-analysis. Other variables were also taken into account as possible effect modifiers: doses of Zn intake, intervention duration, nutritional status, and risk of bias. From each select growth study, final measures of weight, length, mid upper arm circumference (MUAC), head circumference, weight for age z-score (WAZ), length for age z-score (LAZ), and weight for length z-score (WLZ) were assessed. Pooled β and 95% confidence interval (CI) were calculated. Additionally, we carried out a sensitivity analysis. Zn intake was not associated with weight, length, MUAC, head circumference, and LAZ in the pooled analyses. However, Zn intake had a positive and statistically effect on WAZ (β = 0.06; 95%CI 0.02 to 0.10) and WLZ (β = 0.05; 95%CI 0.01 to 0.08). The dose–response relationship between Zn intake and these parameters indicated that a doubling of Zn intake increased WAZ and WLZ by approximately 4%. Substantial heterogeneity was present only in length analyses (I2 = 45%; p = 0.03). Zn intake was positively associated with length values at short time (four to 20 weeks) (β = 0.01; CI 95% 0 to 0.02) and at medium doses of Zn (4.1 to 8 mg/day) (β = 0.003; CI 95% 0 to 0.01). Nevertheless, the effect magnitude was small. Our results indicate that Zn intake increases growth parameters of infants. Nonetheless, interpretation of these results should be carefully considered

Fenología reproductiva de Pouteria splendens (Sapotaceae)

Pouteria splendens (A.DC.) Kuntze (lúcumo silvestre, palo colorado) is an endemic and in dangered tree from CentralChile. It´s the only member of the Sapotaceae family in the country and little is known about his life cycle. We studiedthe reproductive phenology during Spring and Summer, from September 2007 to April 2008, on the biggest remainedpopulation of P. splendens, located in Los Molles (V Región Valparaíso). We recorded an increase in the productionof flower buds, flowers and fruits from September to February, decaying in March. According with other species fromMediterranean environments, the peak of flower buds, flowers and fruits was recorded during Summer, in February. Wealso detected a high synchrony in the phenology among the individuals within the population.Pouteria splendens (A.DC.) Kuntze (lúcumo silvestre, palo colorado) es un arbusto endémico con problemas deconservación de Chile central. Es la única especie representante de la familia Sapotaceae en el país y se conoce muy pocode su ciclo de vida. Se estudió su fenología reproductiva durante la primavera y verano, desde septiembre 2007 hastaabril 2008, en la población remanente más grande, localizada en Los Molles (V Región de Valparaíso). Se encontró unincremento en la producción de yemas florales, flores y frutos desde septiembre a febrero, decayendo en marzo. Al igualque en otras especies de ambientes mediterráneos, el máximo en la formación de botones florales, flores y frutos ocurrióen época de verano, durante febrero. También detectamos una alta sincronía en la fenología entre los individuos en lapoblación estudiada

Contenidos, metodología y alumnado : una valoración crítica de la enseñanza en BUP y COU

The aim of this study was to compare the interest of the students in Natural Science in front of three other subjects such as Mathematics, Literature and Geography & History. The selected items of the contents of every subject, and the importance of teaching as an influential factor on students were also studied. The results showed that both the selection of the contents and the methods should have been modified