Debate: Do all patients with heart failure require implantable defibrillators to prevent sudden death?

Sudden death is a major cause of mortality in patients with ventricular dysfunction. The highest risk occurs among patients with less severe functional impairment. Current methods of risk stratification are inadequate, and a rational therapy for prevention of sudden death is not available. The implantable cardioverter-defibrillator (ICD) has proven to be more effective than drugs in reducing sudden-death risk in some subsets of patients. Empiric ICD therapy, targeting the general population with mild to moderate heart failure, will maximize the impact of such a strategy to prevent sudden death and improve long-term survival

Diversidad de floraciones de especies de algas nocivas en el área central del estuario del Río Bonny, delta del Níger, Nigeria

This study was carried out from December 2018 to November 2019 to examine the distribution and abundance of harmful algal species (HAS) in the central Bonny estuary. Seven sampling stations were established with ArcGIS tool. Microalgae species were sampled with 20 mm mesh plankton net. Nutrients were analyzed in the laboratory using the APHA 4500 Method, while physicochemical characteristics were determined in situ. Results revealed that environmental gradients were adequate to support life in that part of the estuary except for phosphate (2.90 ± 0.22-9.48 ± 1.06 mg l-1). A total of 31 HASs categorized into 17 genera and three classes were determined: Bacillariophyceae (29 species), Chlorophyceae and Cyanophyceae (one species each). Navicula amphibola had the highest density (4.713 103 cells l-1) while Pinnularia divergens recorded the lowest density (0.00049 103 cells l-1). Total density values decreased across seasons with 9.157 103 cells l-1 in dry season and 8.907 103 cells l-1 in wet season. Checklist of species across stations showed that five species were distributed across the seven stations, while two were found only in Station 2 and 7. Diversity indices revealed Shannon’s index ranged between 3.17 and 3.25 and species evenness ranged between 0.78 and 0.88, while Margalef range value (3.09-3.31) was considered moderately stable. Therefore, there is a need for proper management practices which could help to reduce the level of nutrient discharge into the central Bonny estuary.Este estudio se llevó a cabo entre diciembre de 2018 y noviembre de 2019 para examinar la distribución y abundancia de especies de algas nocivas (HAS, por sus siglas en inglés) en el área central del estuario del río Bonny. Se establecieron siete estaciones de muestreo con la herramienta ArcGIS. Las especies de microalgas se muestrearon con una red de plancton de 20 mm de malla. Los nutrientes se analizaron en laboratorio mediante el Método APHA 4500, mientras que las características fisicoquímicas se determinaron in situ. Los resultados revelaron que los gradientes ambientales fueron adecuados para sustentar la vida en esa parte del estuario, excepto por el fosfato (2,90 ± 0,22 - 9,48 ± 1,06 mg l-1). Se determinaron un total de 31 HAS categorizadas en 17 géneros y tres clases: Bacillariophyceae (29 especies), Chlorophyceae y Cyanophyceae (una especie cada una). Navicula amphibola tuvo la mayor densidad (4,713 x 103 células l-1) mientras que Pinnularia divergens registró la menor densidad (0,00049 x 103 células l-1). Los valores de densidad total disminuyeron a través de las estaciones con 9,157 x 103 células l-1 en la estación seca y 8,907 x 103 células l-1 en la estación húmeda. La lista de especies en las estaciones mostró que cinco especies se distribuyeron en las siete estaciones, mientras que dos se encontraron solo en las estaciones 2 y 7. Los índices de diversidad revelaron que el índice de Shannon osciló entre 3,17 y 3,25 y la uniformidad de las especies osciló entre 0,78 y 0,88, mientras que el valor del rango de Margalef (3,09-3,31) se consideró moderadamente estable. Por lo tanto, existe la necesidad de prácticas de gestión adecuadas que podrían ayudar a reducir el nivel de descarga de nutrientes en el área central del estuario del Bonny

Chemical and Statistical Analysis of a Sampled Interval in the Camp Nelson Limestone (Upper Ordovician) Madison County, Central Kentucky

The Camp Nelson Limestone of the High Bridge Group (Upper Ordovician) is mined at seven sites in central and north-central Kentucky for industrial, construction, and agricultural uses. As part of a regional investigation of its chemical characteristics, a 67-foot section in the upper Camp Nelson, which is being mined at Boonesborough, Madison County, was sampled for major-element analysis. The upper Camp Nelson in the Boonesborough Mine consists of two zones (23 and 30 feet thick) of low-silica stone (4 percent or less total SiO2) separated by a 14-foot section of slightly argillaceous limestone with an average silica content of 5.19 percent. The lower 23-foot zone has an average silica content of 1.75 percent and an average total carbonate (CaCO3 + MgCO3) content of 96.03 percent. The upper 30-foot zone has an average silica content of 2.48 percent and an average total carbonate content of 93.17 percent. A statistical study showed a relationship between the sampling interval and the reliability of the mean carbonate (or contaminant) value for a limestone ledge. Moderately high reliability (0.80 to 0.85) can be obtained by taking three to four samples per ledge. If only high reliability (0.90) of the mean value is acceptable, samples should be taken at 1-foot intervals. Very high reliability would require sampling at 1/2-foot intervals

Ernst Freund as Precursor of the Rational Study of Corporate Law

Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe

Three-dimensional femtosecond laser nanolithography of crystals

Nanostructuring hard optical crystals has so far been exclusively feasible at their surface, as stress induced crack formation and propagation has rendered high precision volume processes ineffective. We show that the inner chemical etching reactivity of a crystal can be enhanced at the nanoscale by more than five orders of magnitude by means of direct laser writing. The process allows to produce cm-scale arbitrary three-dimensional nanostructures with 100 nm feature sizes inside large crystals in absence of brittle fracture. To showcase the unique potential of the technique, we fabricate photonic structures such as sub-wavelength diffraction gratings and nanostructured optical waveguides capable of sustaining sub-wavelength propagating modes inside yttrium aluminum garnet crystals. This technique could enable the transfer of concepts from nanophotonics to the fields of solid state lasers and crystal optics.Comment: Submitted Manuscript and Supplementary Informatio

Observations with the Differential Speckle Survey Instrument. X. Preliminary Orbits of K Dwarf Binaries and Other Stars

This paper details speckle observations of binary stars taken at the Lowell Discovery Telescope, the WIYN Telescope, and the Gemini telescopes between 2016 January and 2019 September. The observations taken at Gemini and Lowell were done with the Differential Speckle Survey Instrument (DSSI), and those done at WIYN were taken with the successor instrument to DSSI at that site, the NN-EXPLORE Exoplanet Star and Speckle Imager (NESSI). In total, we present 378 observations of 178 systems and we show that the uncertainty in the measurement precision for the combined data set is ~2 mas in separation, ~1-2 degrees in position angle depending on the separation, and $\sim$0.1 magnitudes in magnitude difference. Together with data already in the literature, these new results permit 25 visual orbits and one spectroscopic-visual orbit to be calculated for the first time. In the case of the spectroscopic-visual analysis, which is done on the trinary star HD 173093, we calculate masses with precision of better than 1% for all three stars in that system. Twenty-one of the visual orbits calculated have a K dwarf as the primary star; we add these to the known orbits of K dwarf primary stars and discuss the basic orbital properties of these stars at this stage. Although incomplete, the data that exist so far indicate that binaries with K dwarf primaries tend not to have low-eccentricity orbits at separations of one to a few tens of AU, that is, on solar-system scales

Science and Ideology in Economic, Political, and Social Thought

This paper has two sources: One is my own research in three broad areas: business cycles, economic measurement and social choice. In all of these fields I attempted to apply the basic precepts of the scientific method as it is understood in the natural sciences. I found that my effort at using natural science methods in economics was met with little understanding and often considerable hostility. I found economics to be driven less by common sense and empirical evidence, then by various ideologies that exhibited either a political or a methodological bias, or both. This brings me to the second source: Several books have appeared recently that describe in historical terms the ideological forces that have shaped either the direct areas in which I worked, or a broader background. These books taught me that the ideological forces in the social sciences are even stronger than I imagined on the basis of my own experiences. The scientific method is the antipode to ideology. I feel that the scientific work that I have done on specific, long standing and fundamental problems in economics and political science have given me additional insights into the destructive role of ideology beyond the history of thought orientation of the works I will be discussing