212 research outputs found
The sunflower transcription factor HaWRKY76 confers drought and flood tolerance to Arabidopsis thaliana plants without yield penalty
Key message: Arabidopsis transgenic plants expressing the sunflower transcription factor HaWRKY76 exhibit increased yield and tolerance to drought and flood stresses. The genetic construct containing HaWRKY76 is proposed as a potential biotechnological tool to improve crops. Abstract: Water deficit and water excess are abiotic stress factors that seriously affect crops worldwide. To increase the tolerance to such stresses without causing yield penalty constitutes a major goal for biotechnologists. In this survey, we report that HaWRKY76, a divergent sunflower WRKY transcription factor, is able to confer both dehydration and submergence tolerance to Arabidopsis transgenic plants without yield penalty. The expression pattern of HaWRKY76 was analyzed in plants grown in standard conditions and under different watering regimes indicating a regulation by water availability. The corresponding cDNA was isolated and cloned under the control of a constitutive promoter and Arabidopsis plants were transformed with this construct. These transgenic plants presented higher biomass, seed production and sucrose content than controls in standard growth conditions. Moreover, they exhibited tolerance to mild drought or flood (complete submergence/waterlogging) stresses as well as the same or increased yield, depending on the stress severity and plant developmental stage, compared with controls. Drought tolerance occurred via an ABA-independent mechanism and induction of stomatal closure. Submergence tolerance can be explained by the carbohydrate (sucrose and starch) preservation achieved through the repression of fermentation pathways. Higher cell membrane stability and chlorenchyma maintenance could be the nexus between tolerance responses in front of both stresses. Altogether, the obtained results indicated that HaWRKY76 can be a potential biotechnological tool to improve crops yield as well as drought and flood tolerances.Fil: Raineri, Jesica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Ribichich, Karina Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Chan, Raquel Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentin
Hierarchical routing protocols for wireless sensor network: a compressive survey
Wireless Sensor Networks (WSNs) are one of the key enabling technologies for the Internet of Things (IoT). WSNs play a major role in data communications in applications such as home, health care, environmental monitoring, smart grids, and transportation. WSNs are used in IoT applications and should be secured and energy efficient in order to provide highly reliable data communications. Because of the constraints of energy, memory and computational power of the WSN nodes, clustering algorithms are considered as energy efficient approaches for resource-constrained WSNs. In this paper, we present a survey of the state-of-the-art routing techniques in WSNs. We first present the most relevant previous work in routing protocols surveys then highlight our contribution. Next, we outline the background, robustness criteria, and constraints of WSNs. This is followed by a survey of different WSN routing techniques. Routing techniques are generally classified as flat, hierarchical, and location-based routing. This survey focuses on the deep analysis of WSN hierarchical routing protocols. We further classify hierarchical protocols based on their routing techniques. We carefully choose the most relevant state-of-the-art protocols in order to compare and highlight the advantages, disadvantage and performance issues of each routing technique. Finally, we conclude this survey by presenting a comprehensive survey of the recent improvements of Low-Energy Adaptive Clustering Hierarchy (LEACH) routing protocols and a comparison of the different versions presented in the literature
Exhaled Nitric Oxide is Not a Biomarker for Pulmonary Tuberculosis.
To reduce transmission of tuberculosis (TB) in resource-limited countries where TB remains a major cause of mortality, novel diagnostic tools are urgently needed. We evaluated the fractional concentration of exhaled nitric oxide (FeNO) as an easily measured, noninvasive potential biomarker for diagnosis and monitoring of treatment response in participants with pulmonary TB including multidrug resistant-TB in Lima, Peru. In a longitudinal study however, we found no differences in baseline median FeNO levels between 38 TB participants and 93 age-matched controls (13 parts per billion [ppb] [interquartile range (IQR) = 8-26] versus 15 ppb [IQR = 12-24]), and there was no change over 60 days of treatment (15 ppb [IQR = 10-19] at day 60). Taking this and previous evidence together, we conclude FeNO is not of value in either the diagnosis of pulmonary TB or as a marker of treatment response
Field-grown transgenic wheat expressing the sunflower gene HaHB4 significantly outyields the wild type
HaHB4 is a sunflower transcription factor belonging to the homeodomain-leucine zipper I family whose ectopic expression in Arabidopsis triggers drought tolerance. The use of PCR to clone the HaHB4 coding sequence for wheat transformation caused unprogrammed mutations producing subtle differences in its activation ability in yeast. Transgenic wheat plants carrying a mutated version of HaHB4 were tested in 37 field experiments. A selected transgenic line yielded 6% more (P<0.001) and had 9.4% larger water use efficiency (P<0.02) than its control across the evaluated environments. Differences in grain yield between cultivars were explained by the 8% improvement in grain number per square meter (P<0.0001), and were more pronounced in stress (16% benefit) than in non-stress conditions (3% benefit), reaching a maximum of 97% in one of the driest environments. Increased grain number per square meter of transgenic plants was accompanied by positive trends in spikelet numbers per spike, tillers per plant, and fertile florets per plant. The gene transcripts associated with abiotic stress showed that HaHB4’s action was not dependent on the response triggered either by RD19 or by DREB1a, traditional candidates related to water deficit responses. HaHB4 enabled wheat to show some of the benefits of a species highly adapted to water scarcity, especially in marginal regions characterized by frequent droughts.EEA PergaminoFil: González, Fernanda Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Departamento Ecofisiología; Argentina.CONICET-UNNOBA.CITNOBA; ArgentinaFil: Capella, Matías. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Ribichich, Karina Fabiana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Curín, Facundo. CONICET-UNNOBA. CITNOBA, (Pergamino); ArgentinaFil: Giacomelli, Jorge Ignacio. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Ayala, Francisco. INDER/BIOCRES (Rosario); ArgentinaFil: Watson, Gerónimo. INDEAR/BIOCERES (Rosario); ArgentinaFil: Otegui, María Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Ecofisiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Lía Chan, Raquel. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral; Argentin
ANÁLISIS DE LA CALIDAD EN EL SERVICIO DE LOS MICRONEGOCIOS DIRIGIDAS POR MUJERES DE DZITYÁ, YUCATÁN
Actualmente las mujeres están cada vez más presentes dentro del ámbito empresarial y dentro de la microempresa, sin embargo, no están exentas de lidiar con las problemáticas que se presentan en el mercado actual, compitiendo de manera desfavorable con las grandes empresas, sus negocios son poco estructurados, no existe la planeación y carecen muchas veces de capital para la reinversión, siendo, el acercamiento con el cliente su única ventaja competitiva, por lo que el objetivo de esta investigación es analizar la calidad en el servicio de los micronegocios dirigidos por mujeres de Dzityá, Yucatán. Es una investigación de enfoque cuantitativo con un alcance descriptivo y con diseño no experimental de corte transversal, la población de estudio fue de 12,749 clientes con una muestra no probabilística de 202 clientes de un total de 10 micronegocios. Se utilizó el modelo SERVQUAL. La aplicación de la encuesta adaptada arrojó una calificación general para el servicio de -0.39, con respecto a las dimensiones del modelo obtuvieron las siguientes calificaciones: Elementos tangibles (-0.73), Seguridad (-0.37), Fiabilidad (-0.42), Capacidad de respuesta (-0.20) y Empatía (0.24), lo cual significa que los clientes no reciben el nivel de servicio que esperan
An Interdisciplinary Approach to Study the Performance of Second-generation Genetically Modified Crops in Field Trials: A Case Study With Soybean and Wheat Carrying the Sunflower HaHB4 Transcription Factor
Research, production, and use of genetically modified (GM) crops have split the world between supporters and opponents. Up to now, this technology has been limited to the control of weeds and pests, whereas the second generation of GM crops is expected to assist farmers in abiotic stress tolerance or improved nutritional features. Aiming to analyze this subject holistically, in this presentation we address an advanced technology for drought-tolerant GM crops, upscaling from molecular details obtained in the laboratory to an extensive network of field trials as well as the impact of the introduction of this innovation into the market. Sunflower has divergent transcription factors, which could be key actors in the drought response orchestrating several signal transduction pathways, generating an improved performance to deal with water deficit. One of such factors, HaHB4, belongs to the homeodomain-leucine zipper family and was first introduced in Arabidopsis. Transformed plants had improved tolerance to water deficits, through the inhibition of ethylene sensitivity and not by stomata closure. Wheat and soybean plants expressing the HaHB4 gene were obtained and cropped across a wide range of growing conditions exhibiting enhanced adaptation to drought-prone environments, the most important constraint affecting crop yield worldwide. The performance of wheat and soybean, however, differed slightly across mentioned environments; whereas the improved behavior of GM wheat respect to controls was less dependent on the temperature regime (cool or warm), differences between GM and wild-type soybeans were remarkably larger in warmer compared to cooler conditions. In both species, these GM crops are good candidates to become market products in the near future. In anticipation of consumers’ and other stakeholders’ interest, spectral analyses of field crops have been conducted to differentiate these GM crops from wild type and commercial cultivars. In this paper, the potential impact of the release of such market products is discussed, considering the perspectives of different stakeholders.Fil: González, Fernanda Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Rigalli, Nicolas Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; ArgentinaFil: Miranda, Patricia Vivian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Romagnoli, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; ArgentinaFil: Ribichich, Karina Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Trucco, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Portapila, Margarita Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; ArgentinaFil: Otegui, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Chan, Raquel Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; Argentin
Successful field performance in warm and dry environments of soybean expressing the sunflower transcription factor HB4
Ribichich, Karina Fabiana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral Santa Fe, Argentina.Chiozza, Mariana. INDEAR/BIOCERES. Rosario, Argentina.Ávalos Britez, Selva. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino (EEA Pergamino). Pergamino, Buenos Aires, Argentina.Cabello, Julieta V. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral Santa Fe, Argentina.Arce, Augustin L. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral Santa Fe, Argentina.Watson, Gerónimo. INDEAR/BIOCERES. Rosario, Argentina.Arias, Claudia. Universidad Nacional de Rosario. CIFASIS. Rosario, Argentina.Portapila, Margarita. Universidad Nacional de Rosario. CIFASIS. Rosario, Argentina.Trucco, Federico. INDEAR/BIOCERES. Rosario, Argentina.Otegui, María Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino (EEA Pergamino). Pergamino, Buenos Aires, Argentina.Chan, Raquel Lía. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Instituto de Agrobiotecnología del Litoral Santa Fe, Argentina.3142–3156Soybean yield is limited primarily by abiotic constraints. No transgenic soybean with improved abiotic stress tolerance is commercially available. We transformed soybean plants with genetic constructs able to express the sunflower transcription factor HaHB4, which confers drought tolerance to Arabidopsis and wheat. One line (b10H) carrying the sunflower promoter was chosen among three independent lines because it exhibited the best performance in seed yield, and was evaluated in the greenhouse and in 27 field trials in different environments in Argentina. In greenhouse experiments, transgenic plants showed increased seed yield under stress conditions together with greater epicotyl diameter, larger xylem area, and increased water use efficiency compared with controls. They also exhibited enhanced seed yield in warm and dry field conditions. This response was accompanied by an increase in seed number that was not compensated by a decrease in individual seed weight. Transcriptome analysis of plants from a field trial with maximum difference in seed yield between genotypes indicated the induction of genes encoding redox and heat shock proteins in b10H. Collectively, our results indicate that soybeans transformed with HaHB4 are expected to have a reduced seed yield penalty when cultivated in warm and dry conditions, which constitute the best target environments for this technology
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Are meta-ecosystems organized hierarchically? A model and test in rocky intertidal habitats
Ecosystems are shaped by processes occurring and interacting over multiple temporal and spatial scales. Theory suggests such complexity can be simplified by focusing on processes sharing the same scale as the pattern of interest. This scale-dependent approach to studying communities has been challenged by multiscale meta-ecosystem theory, which recognizes that systems are interconnected by the movement of ‘‘ecological subsidies’’ and suggests that cross-scale feedbacks between local and regional processes can be equally important for understanding community structure. We reconcile these two perspectives by developing and testing a hierarchical meta-ecosystem model. The model predicts local community responses to connectivity over multiple oceanographic spatial scales, defined as macro- (100s of km), meso- (10s of km), and local scale (100s of m). It assumes that local communities occur in distinct regions and that connectivity effects are strongest among local sites. Predictions are that if macroscale processes dominate, then regardless of mesoscale differences, (1) local communities will be similar, and (2) will be even more so with increased connectivity. With dominance of mesoscale (i.e., regional) processes, (3) local structure will be similar within but distinct between regions, and (4) with increased connectivity similar both within and among regions. With dominance of local-scale processes, (5) local communities will differ both within and among regions, and (6) with increased connectivity be similar within but not between regions. We tested the model by evaluating rocky intertidal community structure patterns with variation in ecological subsidies and environmental conditions at 13 sites spanning 725 km of the northern California Current system. External factors operating at meso- and local scales had strong effects, explaining 52% and 27% of the variance, respectively, in community structure. Sessile invertebrate and predator dominance was associated with weaker upwelling, higher phytoplankton abundance, and higher recruitment, and the opposite was true for macrophyte dominance. Overall, our results support the theory that meta-ecosystems are organized hierarchically, with environmental processes dominating at meso- to macroscales and ecological processes playing a more important role at local scales, but with important bidirectional cross-scale interactions.Keywords: variation partitioning, meta-ecosystems, ecological subsidies, relative importance, spatial scale, oceanographic conditions, coastal ecosystems, rocky intertidal communities, ecosystem dynamics, northern California Current large marine ecosyste
Opinion: Why Protect Nature? Rethinking Values and the Environment
A cornerstone of environmental policy is the debate over protecting nature for humans’ sake (instrumental values) or for nature’s (intrinsic values) (1). We propose that focusing only on instrumental or intrinsic values may fail to resonate with views on personal and collective well-being, or “what is right,” with regard to nature and the environment. Without complementary attention to other ways that value is expressed and realized by people, such a focus may inadvertently promote worldviews at odds with fair and desirable futures. It is time to engage seriously with a third class of values, one with diverse roots and current expressions: relational values. By doing so, we reframe the discussion about environmental protection, and open the door to new, potentially more productive policy approaches
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Incorporating Experience Curves in Appliance Standards Analysis
The technical analyses in support of U.S. energy conservation standards for residential appliances and commercial equipment have typically assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. There is, however, considerable evidence that this assumption does not reflect real market prices. Costs and prices generally fall in relation to cumulative production, a phenomenon known as experience and modeled by a fairly robust empirical experience curve. Using price data from the Bureau of Labor Statistics, and shipment data obtained as part of the standards analysis process, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These allow us to develop more representative appliance price projections than the assumption-based approach of constant prices. These experience curves were incorporated into recent energy conservation standards for these products. The impact on the national modeling can be significant, often increasing the net present value of potential standard levels in the analysis. In some cases a previously cost-negative potential standard level demonstrates a benefit when incorporating experience. These results imply that past energy conservation standards analyses may have undervalued the economic benefits of potential standard levels
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