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- ItemA holistic view of nitrogen acquisition in plants(2011) Kraiser Miranda, Tatiana Diannela; Gutiérrez Ilabaca, Rodrigo Antonio
- ItemA modeling approach to determining the relationship between vegetative filter strip design and sediment composition(2017) Lobo, G.; Bonilla Meléndez, Carlos Alberto; CEDEUS (Chile)
- ItemA multipurpose portable instrument for determining ripeness in wine grapes using NIR spectroscopy(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2008) Larrain, Manuel; Guesalaga, Andres R.; Agosin, EduardoThis paper describes the development of a noninvasive instrument that is designed to measure three parameters of ripeness in wine grapes, i.e., sugar (Brix), pH, and anthocyanin concentration. The instrument is based on near-infrared spectroscopy, and it comes in contact with the berry in the cluster without altering its ripening process. A thorough description of the calibration process for the instrument is done for the different grape varieties, e.g., Cabernet Sauvignon, Carmenere, Merlot, Pinot Noir, and Chardonnay. Samples from vineyards located in the Maipo Valley (Chile) taken during the 2003 season were processed to develop calibration models using partial least squares techniques. The models were validated in terms of root mean square error of validation and R-2 indices. The results show the great potential of this technique regarding Brix and pH measurements. For the anthocyanin concentration measurements, the results are promising but require an accurate procedure to obtain reference values for model calibration. The instrument can be useful for sampling strategies that look for optimum harvest schedules according to grape maturity in terms of not only sugar content but also pH and anthocyanin concentration.
- ItemA new method of assessing water erosion risk in forest operations based on rainfall variability(UNIV AUSTRAL CHILE, FAC CIENCIAS FORESTALES, 2012) Contreras, Juan; Bonilla, Carlos A.; Troncoso, JuanWater erosion has been a major environmental problem associated to forest harvesting operations in humid and temperate climates. The incorporation of this factor in the decision making process has been complex due to the high variability observed in rainfall intensity and magnitude. This paper presents a methodology for incorporating the temporal variability of rainfall in the planning of forest operations. We used a monthly index based on the R-RUSLE erosivity factor. This index allows knowing the most likely value of soil loss and associating a confidence level. Thus, the forest planner has an estimate of erosion rates related to the operations, and an index that reflects the rainfall variability. With this methodology it is possible to identify, for a given level of soil loss, those months in which there is a higher uncertainty. This methodology was applied to a pine plantation in Santa Barbara, Biobio Region, Chile, where the rainfall erosivity ranges from 16 MJ mm ha(-1) h(-1) to 271 MJ mm ha(-1) h(-1) depending on the month of the year.
- ItemA new species of Pseudococcus (Hemiptera: Pseudococcidae) belonging to the "Pseudococcus maritimus" complex from Chile: molecular and morphological description(MAGNOLIA PRESS, 2011) Correa, Margarita; Aguirre, Carlos; Germain, Jean Francois; Hinrichsen, Patricio; Zaviezo, Tania; Malausa, Thibaut; Prado, ErnestoA new species of mealybug from Chile, Pseudococcus meridionalis Prado sp. n., is described and illustrated based on the morphological and molecular characterization of adult females. This species belongs to the "Pseudococcus maritimus" complex and displays a wide host plant range, including Japanese pear, persimmon, pomegranate, pear and grape.
- ItemA non-destructive digital imaging method to predict immobilized yeast-biomass(ELSEVIER, 2009) Acevedo, Cristian A.; Skurtys, Olivier; Young, Manuel E.; Enrione, Javier; Pedreschi, Franco; Osorio, FernandoIn food fermentation, many types of immobilization systems are used, such as hydrogel entrapment, where alginate is the main biopolymer. one of the important problems in industrial processes is the quantifications of biomass, since the traditional system of direct cell counting cannot be used. In this study, a simple digital imaging method to determine the biomass of yeasts immobilized into alginate capsules was developed. Important evidence of the yeasts growing inside the alginate was the change in the surface color of the capsule. Digital images were taken with different biomass concentration, and the RGB-analysis showed significant differences in the blue field. The histogram of the blue channel was used to develop a PLS multivariate calibration to predict biomass concentration. The method was validated in primary beer fermentation with good efficiency. (C) 2009 Elsevier Ltd. All rights reserved.
- ItemA randomized trial of a screening, case finding, and referral system for older veterans in primary care(WILEY, 2007) Rubenstein, Laurence Z.; Alessi, Cathy A.; Josephson, Karen R.; Hoyl, M. Trinidad; Harker, Judith O.; Pietruszka, Fern M.OBJECTIVES: To test whether a system of screening, assessment, referral, and follow-up provided within primary care for high-risk older outpatients improves recognition of geriatric conditions and healthcare outcomes.
- ItemA rapid, sensitive and inexpensive method for detection of grapevine red blotch virus without tissue extraction using loop-mediated isothermal amplification(2019) Romero, J. L.; Carver, G. D.; Arce Johnson, Jorge Patricio; Perry, K. L.; Thompson, J. R.
- ItemA remarkable synergistic effect at the transcriptomic level in peach fruits doubly infected by prunus necrotic ringspot virus and peach latent mosaic viroid(2013) Herranz, Mari C.; Niehl, Annette; Rosales V., Marlene; Fiore, Nicola; Zamorano, Alan; Granell, Antonio; Pallas, VicenteAbstract Background Microarray profiling is a powerful technique to investigate expression changes of large amounts of genes in response to specific environmental conditions. The majority of the studies investigating gene expression changes in virus-infected plants are limited to interactions between a virus and a model host plant, which usually is Arabidopsis thaliana or Nicotiana benthamiana. In the present work, we performed microarray profiling to explore changes in the expression profile of field-grown Prunus persica (peach) originating from Chile upon single and double infection with Prunus necrotic ringspot virus (PNRSV) and Peach latent mosaic viroid (PLMVd), worldwide natural pathogens of peach trees. Results Upon single PLMVd or PNRSV infection, the number of statistically significant gene expression changes was relatively low. By contrast, doubly-infected fruits presented a high number of differentially regulated genes. Among these, down-regulated genes were prevalent. Functional categorization of the gene expression changes upon double PLMVd and PNRSV infection revealed protein modification and degradation as the functional category with the highest percentage of repressed genes whereas induced genes encoded mainly proteins related to phosphate, C-compound and carbohydrate metabolism and also protein modification. Overrepresentation analysis upon double infection with PLMVd and PNRSV revealed specific functional categories over- and underrepresented among the repressed genes indicating active counter-defense mechanisms of the pathogens during infection. Conclusions Our results identify a novel synergistic effect of PLMVd and PNRSV on the transcriptome of peach fruits. We demonstrate that mixed infections, which occur frequently in field conditions, result in a more complex transcriptional response than that observed in single infections. Thus, our data demonstrate for the first time that the simultaneous infection of a viroid and a plant virus synergistically affect the host transcriptome in infected peach fruits. These field studies can help to fully understand plant-pathogen interactions and to develop appropriate crop protection strategies.Abstract Background Microarray profiling is a powerful technique to investigate expression changes of large amounts of genes in response to specific environmental conditions. The majority of the studies investigating gene expression changes in virus-infected plants are limited to interactions between a virus and a model host plant, which usually is Arabidopsis thaliana or Nicotiana benthamiana. In the present work, we performed microarray profiling to explore changes in the expression profile of field-grown Prunus persica (peach) originating from Chile upon single and double infection with Prunus necrotic ringspot virus (PNRSV) and Peach latent mosaic viroid (PLMVd), worldwide natural pathogens of peach trees. Results Upon single PLMVd or PNRSV infection, the number of statistically significant gene expression changes was relatively low. By contrast, doubly-infected fruits presented a high number of differentially regulated genes. Among these, down-regulated genes were prevalent. Functional categorization of the gene expression changes upon double PLMVd and PNRSV infection revealed protein modification and degradation as the functional category with the highest percentage of repressed genes whereas induced genes encoded mainly proteins related to phosphate, C-compound and carbohydrate metabolism and also protein modification. Overrepresentation analysis upon double infection with PLMVd and PNRSV revealed specific functional categories over- and underrepresented among the repressed genes indicating active counter-defense mechanisms of the pathogens during infection. Conclusions Our results identify a novel synergistic effect of PLMVd and PNRSV on the transcriptome of peach fruits. We demonstrate that mixed infections, which occur frequently in field conditions, result in a more complex transcriptional response than that observed in single infections. Thus, our data demonstrate for the first time that the simultaneous infection of a viroid and a plant virus synergistically affect the host transcriptome in infected peach fruits. These field studies can help to fully understand plant-pathogen interactions and to develop appropriate crop protection strategies.
- ItemA salicylic acid-induced lectin-like protein plays a positive role in the effector-triggered immunity response of arabidopsis thaliana to pseudomonas syringae Avr-Rpm1(2013) Armijo, Grace; Salinas Salvo, Paula Andrea Ximena; Monteoliva, María Inés; Seguel, Aldo; García, Consuelo; Villarroel Candia, Eva; Song, Wei; Van Der Krol, Alexander Ronald; Álvarez, María Elena; Holuigue Barros, María Loreto
- ItemA Severe Outbreak of Charcoal Rot in Cantaloupe Melon Caused by Macrophomina phaseolina in Chile(2013) Jacob Grez, Cristián Jascha; Krarup Hjort, Christian Frederik; Díaz Ulloa, Gonzalo Alberto; Latorre G., Bernardo
- ItemA simple model for estimating changes in rainfall erosivity caused by variations in rainfall patterns(2018) Lobo, Gabriel P.; Bonilla Meléndez, Carlos Alberto
- ItemA Systems Approach Uncovers Restrictions for Signal Interactions Regulating Genome-wide Responses to Nutritional Cues in Arabidopsis(2009) Krouk, G.; Gutiérrez Ilabaca, Rodrigo Antonio
- ItemA systems view of nitrogen nutrient and metabolite responses in Arabidopsis(2008) Vidal Olate, Elena Alejandra; Gutiérrez Ilabaca, Rodrigo Antonio
- ItemA2-Adrenoceptors Control the Release of Noradrenaline But Not Neuropeptide y From Perivascular Nerve Terminals(2002) Donoso, M. Verónica.; Konig Samohod, Cecilia; Huidobro-Toro, Juan Pablo.
- ItemAB1400-HPR Muscle quality index in obese subjects with hip osteoarthritis(2018) Jérez, D. A.; Machado, R.; Cerda Vega, EnriqueBackground: Obese older adults with hip osteoarthritis suffer a progressive loss of neuromuscular function affecting their activities of daily living. Objectives: The objective of this study is to determine the behaviour of the muscular quality index in obese subjects with osteoarthritis and to compare the manifestations of strength and anthropometric variables with control subjects. Methods: Thirty-two subjects (4 men and 28 women, 66.2±5.2 years of age, 159.2±7.5 cm, 71.5±11.7 kg) were evaluated. 14 subjects suffered osteoarthritis. Muscle circumference, limb length, body mass and sit and stand test were evaluated, in addition to the maximal voluntary isometric contraction in hip flexion and extension movements. Results: The osteoarthritis group presented obesity (p=0.037). The muscle quality index of the osteoarthritis group correlated with the weight (p=0.776**), with maximum peak strength in flexion (p=0.552*) and average maximal strength (p=0.574*). In the control group the muscle quality index correlated with: weight (p=0.689**), muscle circumference (p=0.571*), maximum peak strength in extension (p=0.534*), average peak strength in extension (p=0,523*), average maximal strength in extension (p=0.509*) and maximum impulse in extension (p=0.508*). Conclusions: The muscle quality index is a useful tool to measure muscle quality in the healthy population, but is not clear enough for obese subjects with osteoarthritis, so it is necessary to perform future studies to determine their behaviour.
- ItemAcquisition of germination capacity, photosensitivity, and desiccation tolerance in lettuce seeds(ISTA-INT SEED TESTING ASSOC, 2008) Contreras, S.; Rabara, R.; Bennett, M. A.; Tay, D.; McDonald, M.Germination capacity, photosensilivity, and desiccation tolerance are important attributes that seeds acquire during their development. Exploring the timing of the acquisition of these characteristics is important to better understand how different environmental conditions affecting the mother plant influence seed quality. Lettuce (Lactuca sativa L. cv. 'Tango') seeds were produced in die greenhouse. Seed germination under light and darkness was evaluated in fresh and desiccated seeds at 3, 5, 7, 9. 11, 13, 15. 17, 19, 21, 25, and 31 days after flowering (DAF). Seeds were desiccated approximate to 1 hour after harvest by placing them at 25 degrees C and 57% RK Seeds achieved maximum dry weight (physiological maturity, PM) at 13 DAF. In fresh seeds, 100% germination was observed 7 DAF. Onset of desiccation tolerance occurred 9 DAF, shortly after seed abscisic acid (ABA) concentration was at its highest level and coincident with the presence of abundant oil bodies in cotyledonary cells. Dark germination of fresh seeds increased from 0% at 11 DAF to 86% at 17 DAF and then decreased to less than 20% at 21 DAF. In general, desiccated seeds had lower dark germination percentages than fresh seeds. Onset of lettuce seed photosensitivity during the maturation desiccation phase was coincident with it sharp loss of seed water content from 37 to 11% between 17 and 19 DAF. These results Support the involvement of ABA in storage reserve deposition and acquisition of desiccation tolerance during lettuce seed development and suggest that Changes in seed water content during the maturation desiccation phase are associated with the onset of light requirement for lettuce seed germination.
- ItemAdaptation and Validation of a Methodology for the Measurement of Calcium Fractions in Fruits(2018) Bonomelli de Pinaga, Claudia María; Ignacia Arias, Maria; Villalobos, Lorena
- ItemAdsorption of glyphosate in Chilean soils and its relationship with unoccupied phosphate binding sites(EMPRESA BRASIL PESQ AGROPEC, 2003) Kogan, M; Metz, A; Ortega, RThe objective of this work was to investigate glyphosate adsorption by soils and its relationship with unoccupied binding sites for phosphate adsorption. Soil samples of three Chilean soils series-Valdivia (Andisol), Clarillo (Inceptisol) and Chicureo (Vertisol) - were incubated with different herbicide concentrations. Glyphosate remaining in solution was determined by adjusting a HPLC method with a UV detector. Experimental maximum adsorption capacity were 15,000, 14,300 and 4,700 mug g(-1) for Valdivia, Clarillo, and Chicureo soils, respectively. Linear, Freundlich, and Langmuir models were used to describe glyphosate adsorption. Isotherms describing glyphosate adsorption differed among soils. Maximum adjusted adsorption capacity with the Langmuir model was 231,884, 17,874 and 5,670 mug g(-1) for Valdivia, Clarillo, and Chicureo soils, respectively. Glyphosate adsorption on the Valdivia soil showed a linear behavior at the range of concentrations used and none of the adjusted models became asymptotic. The high glyphosate adsorption capacity of the Valdivia soil was probably a result of its high exchangeable Al, extractable Fe, and alophan and imogolite clay type. Adsorption was very much related to phosphate dynamics in the Valdivia soil, which showed the larger unoccupied phosphate binding sites. However relationship between unoccupied phosphate binding sites and glyphosate adsorption in the other two soils (Clarillo and Chicureo) was not clear.
- ItemAdvances in breeding and biotechnology of legume crops(2016) Jacob, C.; Carrasco Gálvez, Basilio Alejandro; Schwember Neira, Andrés R.