11,477 research outputs found

    Analysis of Two Polyhydroxyalkanoate Synthases in Bradyrhizobium japonicum USDA 110

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    Bradyrhizobium japonicum USDA 110 has five polyhydroxyalkanoate (PHA) synthases (PhaC) annotated in its genome: bll4360 (phaC1), bll6073 (phaC2), blr3732 (phaC3), blr2885 (phaC4), and bll4548 (phaC5). All these proteins possess the catalytic triad and conserved amino acid residues of polyester synthases and are distributed into four different PhaC classes. We obtained mutants in each of these paralogs and analyzed phaC gene expression and PHA production in liquid cultures. Despite the genetic redundancy, only phaC1 and phaC2 were expressed at significant rates, while PHA accumulation in stationary-phase cultures was impaired only in the phaC1 mutant. Meanwhile, the phaC2 mutant produced more PHA than the wild type under this condition, and surprisingly, the phaC3 transcript increased in the phaC2 background. A double mutant, the phaC2 phaC3 mutant, consistently accumulated less PHA than the phaC2 mutant. PHA accumulation in nodule bacteroids followed a pattern similar to that seen in liquid cultures, being prevented in the phaC1 mutant and increased in the phaC2 mutant in relation to the level in the wild type. Therefore, we used these mutants, together with a phaC1 phaC2 double mutant, to study the B. japonicum PHA requirements for survival, competition for nodulation, and plant growth promotion. All mutants, as well as the wild type, survived for 60 days in a carbon-free medium, regardless of their initial PHA contents. When competing for nodulation against the wild type in a 1:1 proportion, the phaC1 and phaC1 phaC2 mutants occupied only 13 to 15% of the nodules, while the phaC2 mutant occupied 81%, suggesting that the PHA polymer is required for successful competitiveness. However, the bacteroid content of PHA did not affect the shoot dry weight accumulation.Fil: Quelas, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Mongiardini, Elias Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Pérez Giménez, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Parisi, Gustavo Daniel. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lodeiro, Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

    Y2K, The Apocalypse, and Evangelical Christianity: The Role of Eschatological Belief in Church Responses

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    Apocalyptic beliefs in Christianity have endured for two thousand years and on occasion have motivated and justified radical and even revolutionary collective action (Boyer 1992). Why apocalyptic visions are part of some Christians\u27 belief system is grounded in their beliefs about the end times, or eschatologies, that shape church cultures and subsequent behaviors. This paper considers cultural aspects of collective action, applying the concept of frames that give events meaning and inspire and legitimize collective behavior to Christian church responses to Y2K as a recent example of an anticipated apocalyptic event. Five interpretive frames linking eschatological ideation with specific collective behaviors are identified and discussed, as well as three corresponding strategic responses to Y2K that were taken by various kinds of Protestant Christian churches as they prepared for the ushering in of a new millennium

    The nitric oxide response in plant-associated endosymbiotic bacteria

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    Nitric oxide (NO) is a gaseous signalling molecule which becomes very toxic due to its ability to react with multiple cellular targets in biological systems. Bacterial cells protect against NO through the expression of enzymes that detoxify this molecule by oxidizing it to nitrate or reducing it to nitrous oxide or ammonia. These enzymes are haemoglobins, c-type nitric oxide reductase, flavorubredoxins and the cytochrome c respiratory nitrite reductase. Expression of the genes encoding these enzymes is controlled by NO-sensitive regulatory proteins. The production of NO in rhizobia–legume symbiosis has been demonstrated recently. In functioning nodules, NO acts as a potent inhibitor of nitrogenase enzymes. These observations have led to the question of how rhizobia overcome the toxicity of NO. Several studies on the NO response have been undertaken in two non-dentrifying rhizobial species, Sinorhizobium meliloti and Rhizobium etli, and in a denitrifying species, Bradyrhizobium japonicum. In the present mini-review, current knowledge of the NO response in those legume-associated endosymbiotic bacteria is summarized

    Sowing time affects the abundance of pests and weeds in winter rye

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    Selection of an appropriate sowing time for some winter rye (Secale cereale) cultivars could reduce the need for crop protection measures. In this study the occurrence and status of pests and weeds in relation to sowing time and growth habit of winter rye was studied in southern Finland. This was done using three sowing times and four rye varieties in field trials conducted at three locations in 1999–2001. The early sown rye was severely affected by pests (Oscinella frit, Mayetiola destructor) and weeds, whereas postponing sowing for two weeks after the recommended sowing time in late August resulted in considerably less damage and the optimal establishment of crop stands. The German hybrid varieties Picasso and Esprit produced more tillers m-2 in autumn than the Finnish varieties Anna and Bor 7068. However, the number of pests and weeds did not differ among rye varieties. Late sowing of rye should be considered to minimize the need for plant protection. If rye is sown at the recommended time it may still require insecticide treatments promptly in the autumn whereas herbicide treatment need not be determined until spring, after recording the winter mortality of weeds

    Determinants of Systemic Risk and Information Dissemination

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    We introduce a measure of information dissemination for the determination of systemic risk, print-media consumer pessimism, controlling for VIX volatility. VIX volatility has a significant direct impact upon systemic risk of financial firms under distress, and consumer pessimism does impact upon firm\u27s financial stress via the externality of other firm\u27s financial stress. In the internet bubble of the 1990s, pessimism predicts larger systemic risk in the whole period of exuberance while the VIX predicts a sharp larger systemic risk in the height of the bubble. Our evidence suggests that consumer pessimism might be dominated by the VIX when predicting systemic risk

    Positive Psychology Within a Cultural Context

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    As our capacity for communication with nations across the globe increases through the advances of technology, our interactions with others with different worldviews also become more frequent. This exposure to diversity on so many levels requires a better understanding of the multiple contexts in which people from different cultural backgrounds live and the strengths they possess that help them experience well-being. In order to define the characteristics that my be viewed as strengths in different groups, we must make efforts to remember that cultural rules and norms often dictate what can be called a strength versus a weakness. It is imperative that we are able to recognize that strengths may look very different in different contexts and that these diverse manifestations may come from a variety of worldviews. More work must be done in order to develop a better understanding of the way that cultural context plays a role in the operationalization, manifestation, and measurement of strengths in diverse groups. The following chapter provides a history of the connections between culture and positive psychology and discusses current issues regarding the link between cultural context and various personal characteristics. Examples from culturally sensitive positive psychology theory and research are also given in order to illustrate how researchers are better exploring positive psychology within a cultural context

    Gene-Gene Interaction between APOA5 and USF1: Two Candidate Genes for the Metabolic Syndrome

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    Objective: The metabolic syndrome, a major cluster of risk factors for cardiovascular diseases, shows increasing prevalence worldwide. Several studies have established associations of both apolipoprotein A5 (APOA5) gene variants and upstream stimulatory factor 1 (USF1) gene variants with blood lipid levels and metabolic syndrome. USF1 is a transcription factor for APOA5. Methods: We investigated a possible interaction between these two genes on the risk for the metabolic syndrome, using data from the German population-based KORA survey 4 (1,622 men and women aged 55-74 years). Seven APOA5 single nucleotide polymorphisms (SNPs) were analyzed in combination with six USF1 SNPs, applying logistic regression in an additive model adjusting for age and sex and the definition for metabolic syndrome from the National Cholesterol Education Program's Adult Treatment Panel III (NCEP (AIII)) including medication. Results: The overall prevalence for metabolic syndrome was 41%. Two SNP combinations showed a nominal gene-gene interaction (p values 0.024 and 0.047). The effect of one SNP was modified by the other SNP, with a lower risk for the metabolic syndrome with odds ratios (ORs) between 0.33 (95% CI = 0.13-0.83) and 0.40 (95% CI = 0.15-1.12) when the other SNP was homozygous for the minor allele. Nevertheless, none of the associations remained significant after correction for multiple testing. Conclusion: Thus, there is an indication of an interaction between APOA5 and USF1 on the risk for metabolic syndrome

    Avisos publicitarios en verso en los primeros años de la revista "Caras y Caretas" (1898-1900): entre el humor, la política y la persuasión

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    In the historiography of argentine advertising, the period from the late nineteenth and early twentieth century is of particular importance, since the first steps of the modern advertising began to form and articulate in those years in a society undergoing the pressure of massive immigration, the emerging middle class, and a working class encouraged by social mobility. This paper analyzes the advertisements graphics in verse in the early years of the magazine Caras y Caretas (1898-1900) as a phenomenon on the way to the autonomy of advertising: from humour and politics to the modern advertising. This rhetorical style radically changed form 1900 when argentine magazines began charging for advertising. The purpose of this paper is to explore the form and functions of this type of ads in Caras y Caretas, 1898-1900, from historical sociolinguistics applied to advertising.En la historiografía de la publicidad argentina, el período comprendido entre los últimos años del siglo XIX y las primeras décadas del siglo XX posee particular importancia ya que comienzan a formarse y articularse en estos años los pasos iniciales de la publicidad moderna en una sociedad bajo la presión de la inmigración masiva, la clase media emergente y la clase trabajadora alentada por la movilidad social. Este trabajo analiza avisos publicitarios gráficos en verso en los primeros años de publicación de la revista Caras y Caretas (1898-1900) como un fenómeno en el camino a la autonomía de la publicidad: desde el humor y la política hacia la publicidad moderna. Este estilo retórico cambió su forma radicalmente en 1900 cuando las revistas argentinas comenzaron a llenarse de anuncios. El propósito de este trabajo es explorar la forma y funciones de este tipo de avisos en Caras y Caretas (1898-1900) desde la perspectiva de la sociolingüística histórica aplicada al discurso publicitario

    Process Integration and Web Services: A Case of Evolutional Development in a Supply Chain

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    Many situations of rapid emergence of a phenomenon are characterised by the fact that a lot of what is written and said is based on ideas, though the discussion may be flavoured by hype rather than anchored in reality - at least in the beginning. Still, there are also situations that constitute real changes. Extensive experiences from spare parts logistics at Volvo are the basis for an up-to-date view of development and use of web services. This paper provides results and experiences from implementations of advanced web service solutions. The origin of these solutions is a desire to improve process integration between supply chain actors. Therefore, the context for business-to-business process integration between suppliers, manufacturers, dealers and customers is also presented. Focus is made on how the usage of IS/IT and management concepts can give extended reach and create closer customer relationships. It is an evolutional development that has often exploited existing strengths and timing of opportunities provided by linking technology and organisational conditions between different actors. The case gives a perspective of Volvos global supply chain, aspects of its evolution and findings concerning timing, culture, installed base and stakeholder relations. The paper provides a general case to the discussion of process integration and in particular, it shares experiences and results from implementation of advanced web services

    On the significance of soil temperature in plant cultivation

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