Analysis of the legume–rhizobia symbiosis in shrubs from central western Spain

s. rodríguez-echeverría, m.a. pérez-fernández, s. vlaar and t. finnan. 2003.Aims: This work analyses the diversity of rhizobia associated with some of the predominant shrubby legumes in central-western Spain. Symbiotic promiscuity and effectiveness were studied using cross-inoculation experiments with shrubby species.Material and Results: Six new bradyrhizobia strains were isolated from nodules collected from wild plants of six leguminous species, Cytisus balansae, C. multiflorus, C. scoparius, C. striatus, Genista hystrix and Retama sphaerocarpa. These isolates were genetically characterized by 16S rDNA partial sequencing and random amplification of polymorphic DNA2013PCR fingerprinting. The phylogenetic analysis revealed that these isolates could represent three new Bradyrhizobium species. Shrubby legumes and bradyrhizobia displayed a high symbiotic promiscuity both for infectivity and effectiveness. Symbioses were effective in more than 70% of the associations established by four of the six plant species.Conclusions: Native woody legumes in western Spain are nodulated by Bradyrhizobium strains. The high degree of symbiotic promiscuity and effectiveness highlights the complex dynamics of these communities in wild ecosystems under a Mediterranean-type climate. Furthermore, the results from this study suggest a potential importance of inoculation for these legume species in soil-restoration projects.Significance and Impact of the Study: This is the first study, to our knowledge, that combines both molecular analysis and pot trials to study the rhizobia2013legume symbiosis for wild legumes

Quantum Conductance Steps in Solutions of Multiwalled Carbon Nanotubes

We have prepared solutions of multiwalled carbon nanotubes in Aroclor 1254, a mixture of polychlorinated biphenyls. The solutions are stable at room temperature. Transport measurements were performed using a scanning--tunneling probe on a sample prepared by spin--coating of the solution on gold substrates. Conductance steps were clearly seen. An histogram of a high number of traces shows maximum peaks at integer values of the conductance quantum $G_0 = 2e^2/h$, demonstrating ballistic transport at room temperature along the carbon nanotube over distances longer than $1.4\mu m$.Comment: 4 pages and 2 figure

Un sistema de construcción para climas tropicales basado en pórticos arriostrados de bambú

A low-cost housing system was developed for use in tropical countries, specifically Haiti, with the aims of minimizing environmental impact (including carbon emissions), maximizing use of local and preferably recycled materials, and using local labor. The housing system integrates low-strength concrete blocks (made using recycled concrete aggregate), an innovative seismically-resistant bamboo frame, earthen plasters, bamboo trusses, and metal deck roofs. The bamboo frame relies on flexural yielding of a short rebar dowel to provide ductile performance at a controlled strength level. The plinth walls below the frame and short rebar dowel protects the bamboo from moisture. The top of a plastic soda bottle is used to protect the rebar from moisture and to seal the base of the bamboo culm, allowing mortar to be introduced into the culm above. This paper focuses on the experimental and analytical results of the flexural yielding of the rebar dowel to establish the structural design of this critical component of the system for resisting wind and seismic loads.En este artículo se presenta un sistema de construcción de viviendas de bajo coste para países tropicales en los cuales existe riesgo sísmico. Los objetivos de este trabajo son generar bajo impacto medioambiental (incluyendo las emisiones de carbono), empleo de materiales locales, preferiblemente reciclados, y mano de obra local. Para esta construcción se han empleado bloques de hormigón de baja resistencia (con agregado reciclado) junto con un innovador sistema de pórticos de bambú, botellas de plástico, vigas de bambú y cubiertas de chapa. El comportamiento dúctil de la estructura se garantiza introduciendo una barra de acero en la base del pórtico de bambú. Para proteger el bambú de la humedad, el pórtico se monta sobre un zócalo. Los resultados experimentales y analíticos obtenidos se utilizan para el diseño estructural del sistema frente a cargas de viento y sísmicas

Diversity of genomic electropherotypes of naturally occurring equine herpesvirus 1 isolates in Argentina

The genomes of 10 equine herpcsvirus 1 (EHV-I) strains isolated in Argentina from 1979 to 1991, and a Japanese HH1 reference strain were compared by restriction endonuclease analysis. Two restriction enzymes, BamHI and Bg/II, were used and analysis of the electropherotypes did not show significant differences among isolates obtained from horses with different clinical signs. This suggests that the EHV-1 isolates studied, which circulated in Argentina for more than 10 years, belong to a single genotype

Contemporary characteristics and outcomes in chagasic heart failure compared with other nonischemic and ischemic cardiomyopathy

Background: Chagas’ disease is an important cause of cardiomyopathy in Latin America. We aimed to compare clinical characteristics and outcomes in patients with heart failure (HF) with reduced ejection fraction caused by Chagas’ disease, with other etiologies, in the era of modern HF therapies. Methods and Results: This study included 2552 Latin American patients randomized in the PARADIGM-HF (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) and ATMOSPHERE (Aliskiren Trial to Minimize Outcomes in Patients With Heart Failure) trials. The investigator-reported etiology was categorized as Chagasic, other nonischemic, or ischemic cardiomyopathy. The outcomes of interest included the composite of cardiovascular death or HF hospitalization and its components and death from any cause. Unadjusted and adjusted Cox proportional hazards models were performed to compare outcomes by pathogenesis. There were 195 patients with Chagasic HF with reduced ejection fraction, 1300 with other nonischemic cardiomyopathy, and 1057 with ischemic cardiomyopathy. Compared with other etiologies, Chagasic patients were more often female, younger, and had lower prevalence of hypertension, diabetes mellitus, and renal impairment (but had higher prevalence of stroke and pacemaker implantation) and had worse health-related quality of life. The rates of the composite outcome were 17.2, 12.5, and 11.4 per 100 person-years for Chagasic, other nonischemic, and ischemic patients, respectively—adjusted hazard ratio for Chagasic versus other nonischemic: 1.49 (95% confidence interval, 1.15–1.94; P=0.003) and Chagasic versus ischemic: 1.55 (1.18–2.04; P=0.002). The rates of all-cause mortality were also higher. Conclusions: Despite younger age, less comorbidity, and comprehensive use of conventional HF therapies, patients with Chagasic HF with reduced ejection fraction continue to have worse quality of life and higher hospitalization and mortality rates compared with other etiologies. Clinical Trial Registration: PARADIGM-HF: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01035255; ATMOSPHERE: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00853658

Grupo de estudos entre alunos ingressantes (calouros) e veteranos do instituto de química da UFG: análise do processo de reformulação

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Classical field theory on Lie algebroids: Variational aspects

The variational formalism for classical field theories is extended to the setting of Lie algebroids. Given a Lagrangian function we study the problem of finding critical points of the action functional when we restrict the fields to be morphisms of Lie algebroids. In addition to the standard case, our formalism includes as particular examples the case of systems with symmetry (covariant Euler-Poincare and Lagrange Poincare cases), Sigma models or Chern-Simons theories.Comment: Talk deliverd at the 9th International Conference on Differential Geometry and its Applications, Prague, September 2004. References adde

Detrended Fluctuation Analysis of Systolic Blood Pressure Control Loop

We use detrended fluctuation analysis (DFA) to study the dynamics of blood pressure oscillations and its feedback control in rats by analyzing systolic pressure time series before and after a surgical procedure that interrupts its control loop. We found, for each situation, a crossover between two scaling regions characterized by exponents that reflect the nature of the feedback control and its range of operation. In addition, we found evidences of adaptation in the dynamics of blood pressure regulation a few days after surgical disruption of its main feedback circuit. Based on the paradigm of antagonistic, bipartite (vagal and sympathetic) action of the central nerve system, we propose a simple model for pressure homeostasis as the balance between two nonlinear opposing forces, successfully reproducing the crossover observed in the DFA of actual pressure signals

A substituted sulfonamide and its Co (II), Cu (II), and Zn (II) complexes as potential antifungal agents

A sulfonamide 1-tosyl-1-H-benzo(d)imidazol-2-amine (TBZA) and three new complexes of Co(II), Cu(II), and Zn(II) have been synthesized. The compounds have been characterized by elemental analyses, FTIR, 1H, and 13C-NMR spectroscopy. The structure of the TBZA, and its Co(II) and Cu(II) complexes, was determined by X-ray diffraction methods. TBZA and its Co(II) complex crystallize in the triclinic P-1 space group, while the Cu(II) complex crystallizes in the monoclinic P21/c space group. Antifungal activity was screened against eight pathogenic yeasts: Candida albicans (DMic 972576), Candida krusei (DMic 951705), Candida glabrata (DMic 982882), Candida tropicalis (DMic 982884), Candida dubliniensis (DMic 93695), Candida guilliermondii (DMic 021150), Cryptococcus neoformans (ATCC 24067), and Cryptococcus gattii (ATCC MYA-4561). Results on the inhibition of various human (h) CAs, hCA I, II, IV, VII, IX, and XII, and pathogenic beta and gamma CAs are also reported.Facultad de Ciencias ExactasInstituto de Física La PlataCentro de Química Inorgánic

The Hamilton-Pontryagin Principle and Multi-Dirac Structures for Classical Field Theories

We introduce a variational principle for field theories, referred to as the Hamilton-Pontryagin principle, and we show that the resulting field equations are the Euler-Lagrange equations in implicit form. Secondly, we introduce multi-Dirac structures as a graded analog of standard Dirac structures, and we show that the graph of a multisymplectic form determines a multi-Dirac structure. We then discuss the role of multi-Dirac structures in field theory by showing that the implicit Euler-Lagrange equations for fields obtained from the Hamilton-Pontryagin principle can be described intrinsically using multi-Dirac structures. Lastly, we show a number of illustrative examples, including time-dependent mechanics, nonlinear scalar fields, Maxwell's equations, and elastostatics.Comment: Uses RevTeX; this article supersedes arXiv:1008.025