Browsing by Author "Retamales, J."

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    Effectiveness of 1-Mcp on Postharvest Deterioration of Nectarines and Peaches Stored At Different Temperatures
    (2002) Zoffoli, Juan Pablo; Balbontín, S.; Retamales, J.; Defilippi, B.
    Flesh browning, mealiness and softening are the main causes of postharvest deterioration of peaches and nectarines. The gas application of three concentrations of 1- Methylcyclopropene (1-MCP) (0.5; 1.0; 1.5 g/m(3)) was evaluated on one peach (`September Sun'), and two nectarine (`Arctic Snow' and `Flamekist') cultivars stored for 17, 23 and 34 days at 0, 5 and 10 degreesC. The gas was applied at 20 degreesC for a period of 48 hours and the different concentrations were compared with a delay cooling process done under the same conditions and with control fruit where the fruit were cooled rapidly. High incidence of flesh browning and mealiness was obtained with all the cultivars after 23 days of storage at 0 and 5 degreesC, otherwise total reduction was attained at 10 degreesC but with a high rate of fruit softening. 1-MCP did not reduce fruit softening at 10 degreesC. Delay cooling reduced the incidence of mealiness in all the cultivars after 17 days of storage at all the temperatures evaluated, but high rate of softening was obtained. Although 1-MCP maintained fruit firmness, the combination with the delay cooling procedure reduced the effectiveness of the later to avoid meatiness. The best result of delay cooling and 1-MCP treatments was obtained with `Arctic Snow' cultivar with the lowest concentration of 1-MCP evaluated.
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    Inter Simple Sequence Repeat Markers Associated with Flowering Time Duration in the Chilean Strawberry (Fragaria chiloensis)
    (2013) Carrasco Gálvez, Basilio Alejandro; Retamales, J.; Quiroz, K.; Garriga, M.; Caligari, P.; García Gonzáles, R.
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    Mendelian Randomization Analysis of the Relationship Between Native American Ancestry and Gallbladder Cancer Risk
    (2022) Zollner, L.; Boekstegers, F.; Ponce, C.B.; Scherer, D.; Marcelain, K.; Gárate-Calderón, V.; Waldenberger, M.; Morales, E.; Rojas, A.; Munoz, C.; Müller, B.; Retamales, J.; de Toro, G.; Kortmann, A.V.; Barajas, O.; Rivera, M.T.; Cortés, A.; Loader, D.; Saavedra, J.; Gutiérrez, L.; Ortega, A.; Bertrán, M.E.; Bartolotti, L.; Gabler, F.; Campos, M.; Alvarado, J.; Moisán, F.; Spencer, L.; Nervi Nattero, Bruno; Carvajal, D.; Losada, H.; Almau, M.; Fernández, P.; Olloquequi, J.; Carter, A.R.; Miquel, Juan Francisco; Bustos, B.I.; Guajardo, M.F.; Gonzalez-Jose, R.; Bortolini, M.C.; Acuña-Alonzo, V.; Gallo, C.; Linares, A.R.; Rothhammer, F.; Bermejo, J.L.
    Background A strong association between the proportion of Native American ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest Native American people in Chile. We set out to investigate the causal association between Native American Mapuche ancestry and GBC risk, and the possible mediating effects of gallstone disease and body mass index (BMI) on this association. Methods Markers of Mapuche ancestry were selected based on the informativeness for assignment measure and then used as instrumental variables in two-sample mendelian randomization (MR) analyses and complementary sensitivity analyses. Result We found evidence of a causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% for every 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.6×10-5). Mapuche ancestry was also causally linked to gallstone disease (IVW risk increase of 3.6% per 1% increase in Mapuche proportion, 95% CI 3.1% to 4.0%, p = 1.0×10-59), suggesting a mediating effect of gallstones in the relationship between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative causal effect on BMI (IVW estimate -0.006 kg/m2 per 1% increase in Mapuche proportion, 95% CI -0.009 to -0.003, p = 4.4×10-5). Conclusions The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between Mapuche ancestry and GBC risk previously noted in observational studies appears to be causal, primary and secondary prevention strategies that take into account the individual proportion of Mapuche ancestry could be particularly efficient.