Effect of Amino Acids on the Nature of the Nitrogenase System in Aerobacker Aerogens

In the past 30 years many aspects of biological nitrogen fixation have been studied intensively by many different workers. These studies have included: the agents of fixation, the physiology of fixation, inhibitors of fixation, and cell free nitrogen fixation and symbiont relationships during fixation. Ten years ago workers in the field postulated the nitrogenase system was adaptive in nature. This was the result of several workers finding it necessary to add a small amount of fixed nitrogen to their cultures before they would fix atmospheric nitrogen. Thus far the only work that has been done on the inductive phenomenon of the nitrogenase system has been by other workers in this laboratory. Results from recent study in this laboratory of the effects of nitrogen supplements on nitrogen fixation suggest that amino acid supplement and the free amino acid pool play a significant role in the formation of the nitrogen fixing enzymes

Notes on Recent Cases

Notes on recent cases by Joseph Yoch, Carl Frankovitch, J. H. Tuberty, Francis G. Fedder, and Robert F. Eggeman

Recent Decisions

Comments on recent decisions by Kenneth K. Konop, Raymond J. Sullivan, Robert E. Duffy, Joseph Yoch, Carl Frankovitch, Joseph Wetli, Harold Tuberty, and Alvin G. Kolski

Dynamic characterization of meandering channels planform

Meandering channels develop different geometry patterns alongthe floodplain during its evolution. These natural processes lead todeveloping lateral and longitudinal migration, describing a sort of sweptthat affect the human activities. As the equilibrium geometry of naturalchannels depends on: the flow and sediment discharge, geologicalconditions of valley, soil properties, and vegetation among others, thepreliminary characterization is not easy. Due to this, several engineering and scientific problems require an appropriate description ofmorphological processes. The dynamic characterization like thequantification of wavelength, amplitude, sinuosity, and curvature usingMedium Temporal Scheme (MTS) is using widely. Unlike the traditionalscheme that only uses short or long-term schemes, MTS includes relevantmorphological events (e.g., cutoff). In addition this, the satellite images has increased and achieves a high spatial resolution, even more when studying large basins. This paper presents and validates a MATLAB®-based toolbox called Meander Statistics Toolbox (MStaT) to perform thedynamic characterization of several meandering channels using the MTS.To run MStaT only need the centerline (CL), and the average width ofchannel as input parameters. To maximize the toolbox, MStaT incorporatesthe Wavelet Analysis (WA) to decompose the signal (CL) and obtains thepower spectrum. Finally, two studies cases (synthetic and natural channels) will be presented to validate MStaT.Fil: Dominguez Ruben, Lucas Gerardo. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Departamento de Hidráulica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutierrez, Ronald. Universidad de Ingeniería y Tecnologia; PerúFil: Ponte, Yoch. Universidad de Ingeniería y Tecnologia; PerúFil: Abad, Jorge D.. Universidad de Ingeniería y Tecnologia; PerúFil: Carrera, Oscar. Universidad de Ingeniería y Tecnologia; Per

Estilo de Vida y su Relación con el Estado Nutricional en pacientes Adultos Mayores con Hipertensión Arterial en el Hospital de Huaycán de Lima

The objective of the research was to determine the relationship between lifestyle and nutritional status in older adult patients with high blood pressure at the Huaycán Hospital in Lima. A study of a hypothetical deductive method was developed, with a quantitative approach, applied type, correlational level and non-experimental, cross-sectional design; in a sample 84 participants; The instruments that allowed data to be collected were two questionnaires, the first called a personalized healthy lifestyle and nutrition questionnaire; The second was an anthropometric data collection sheet. According to the results; 50% of the participants evidenced a healthy lifestyle and the other 50% evidenced an unhealthy lifestyle. On the other hand, 47.6% reported moderate malnutrition, 23.8% mild malnutrition, 20.2% severe malnutrition and 9.3% reported normal nutritional status. Likewise, it was possible to determine that it exists in the dimensions of lifestyles (Food, stress management, interpersonal support, self-realization, responsibility in health) and nutritional status, where the p value was less than 0.05. It is concluded by determining that there is a relationship between lifestyle and nutritional status in older adult patients with arterial hypertension; with a result of the p value equal to 0.004.La investigación tuvo como objetivo determinar la relación entre el estilo de vida y el estado nutricional en pacientes adultos mayores con hipertensión arterial en el Hospital de Huaycán de Lima. Se desarrollo un estudio de método hipotético deductivo, con enfoque cuantitativo, de tipo aplicado, de nivel correlacional y diseño no experimental, de corte transversal; en una muestra 84 participantes; los instrumentos que permitieron recoger los datos fueron dos cuestionarios, el primero denominado cuestionario personalizado de estilo de vida saludable y nutrición; el segundo fue una ficha de recoleccion de datos antropométricos. Según los resultados; el 50% de los participantes evidenciaron un estilo de vida saludable y el otro 50% evidenxaron un estilo de vida no saludable. Por otra parte el 47,6% evienció desnutricion moderada, el 23,8% desnutricion leve, el 20,2 desnutricion severa y el 9,3% estado nutricionl normal. Asimismo se pudo dererminar que existe en las dimension de los estilos de vida (Alimentación, manejo del estrés, apoyo interpersonal, autorealizacion, responsabilidad en salud) y el estado nutricional, donde los valor de p, fueron menor a 0,05. Se concluye determinando que existe relación entre el estilo de vida y el estado nutricional en pacientes adultos mayores con hipertensión arterial; con un resultado del valor de p igual a 0,004

Predominance of deterministic microbial community dynamics in salterns exposed to different light intensities

While the dynamics of microbial community assembly driven by environmental perturbations have been extensively studied, our understanding is far from complete, particularly for light‐induced perturbations. Extremely halophilic communities thriving in coastal solar salterns are mainly influenced by two environmental factors—salt concentrations and high sunlight irradiation. By experimentally manipulating light intensity through the application of shading, we showed that light acts as a deterministic factor that ultimately drives the establishment of recurrent microbial communities under near‐saturation salt concentrations. In particular, the stable and highly change‐resistant communities that established under high‐light intensities were dominated (>90% of metagenomic reads) by Haloquadratum spp. and Salinibacter spp. On the other hand, under 37‐fold lower light intensity, different, less stable and change‐resistant communities were established, mainly dominated by yet unclassified haloarchaea and relatively diverse photosynthetic microorganisms. These communities harboured, in general, much lower carotenoid pigment content than their high‐irradiation counterparts. Both assemblage types appeared to be highly resilient, re‐establishing when favourable conditions returned after perturbation (i.e. high‐irradiation for the former communities and low‐irradiation for the latter ones). Overall, our results revealed that stochastic processes were of limited significance to explain these patterns.This study was funded by the Spanish Ministry of Economy projects CGL2012-39627-C03-03 CLG2015_66686-C3-1-P and PGC2018-096956-B-C41 (to R.R.M.), CGL2015_66686-C3-3-P (to J.A.) and CGL2015_66686-C3-2-P (to J.E.G.P.), which were also supported with European Regional Development Fund (FEDER) funds. R.A. was funded by the Max Planck Society. KTK’s research was supported, in part, by the U.S. National Science Foundation (Award No. 1831582). T.V.P. received a pre-doctoral fellowship (No. BES-2013-064420) from the Spanish Government Ministry for Finance and Competition. R.R.M. acknowledges the financial support of the sabbatical stay at Georgia Tech supported by the Grant PRX18/00048 of the Ministry of Sciences, Innovation and Universities

Mechanistic insight into acrylate metabolism and detoxification in marine dimethylsulfoniopropionate-catabolizing bacteria

Dimethylsulfoniopropionate (DMSP) cleavage, yielding dimethyl sulfide (DMS) and acrylate, provides vital carbon sources to marine bacteria, is a key component of the global sulfur cycle and effects atmospheric chemistry and potentially climate. Acrylate and its metabolite acryloyl-CoA are toxic if allowed to accumulate within cells. Thus, organisms cleaving DMSP require effective systems for both the utilization and detoxification of acrylate. Here, we examine the mechanism of acrylate utilization and detoxification in Roseobacters. We propose propionate-CoA ligase (PrpE) and acryloyl-CoA reductase (AcuI) as the key enzymes involved and through structural and mutagenesis analyses, provide explanations of their catalytic mechanisms. In most cases, DMSP lyases and DMSP demethylases (DmdAs) have low substrate affinities, but AcuIs have very high substrate affinities, suggesting that an effective detoxification system for acylate catabolism exists in DMSP-catabolizing Roseobacters. This study provides insight on acrylate metabolism and detoxification and a possible explanation for the high Km values that have been noted for some DMSP lyases. Since acrylate/acryloyl-CoA is probably produced by other metabolism, and AcuI and PrpE are conserved in many organisms across all domains of life, the detoxification system is likely relevant to many metabolic processes and environments beyond DMSP catabolism