1,522 research outputs found
Compatibility and relevance: Bolzano and Orlov
For a dozen years the Russian engineer and logician I.E. Orlov has been recognized as the founder of the first precisely elaborated modern system of relevance logic
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Understanding Income Inequality in the United States
In a democracy where the median income is substantially less than the mean, why does the poor majority not implement a significant level of redistribution? Despite fears that democracy would empower the poor majority to such ends, constituents of below average income have a mixed record of utilizing democracy to ameliorate economic inequality in the United States. How do we understand this puzzle? Why does the poor majority not maintain a constant level of redistribution in a democracy? In the first part of my dissertation, I provide a game theoretic answer based on historical research which is in accord with the broad trend in both policy and economic inequality in the United States. In the second part of my dissertation, I present new income tax data for New York City and Philadelphia for the 1860s. Despite limitations, this data offers a glimpse at the income shares of the top 1, 0.1, and 0.01 percent of the population in the two premier US cities during an important period in our economic history – a glimpse previously not possible. As we shall see, the income shares of top one percent in New York City in the 1860s and mid-2000s are comparable. This combined with recent data and our knowledge of US history highlights new questions
Concise Review: The Potential Use of Intestinal Stem Cells to Treat Patients With Intestinal Failure.
: Intestinal failure is a rare life-threatening condition that results in the inability to maintain normal growth and hydration status by enteral nutrition alone. Although parenteral nutrition and whole organ allogeneic transplantation have improved the survival of these patients, current therapies are associated with a high risk for morbidity and mortality. Development of methods to propagate adult human intestinal stem cells (ISCs) and pluripotent stem cells raises the possibility of using stem cell-based therapy for patients with monogenic and polygenic forms of intestinal failure. Organoids have demonstrated the capacity to proliferate indefinitely and differentiate into the various cellular lineages of the gut. Genome-editing techniques, including the overexpression of the corrected form of the defective gene, or the use of CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 to selectively correct the monogenic disease-causing variant within the stem cell, make autologous ISC transplantation a feasible approach. However, numerous techniques still need to be further optimized, including more robust ex vivo ISC expansion, native ISC ablation, and engraftment protocols. Large-animal models can to be used to develop such techniques and protocols and to establish the safety of autologous ISC transplantation because outcomes in such models can be extrapolated more readily to humans.The field of intestinal stem cell biology has exploded over the past 5 years with discoveries related to in vivo and in vitro stem cell identity and function. The goal of this review article is to highlight the potential use of these cells to treat various epithelial disorders of the gut and discuss the various roadblocks that will be encountered in the coming years
Results of the German Dioxin Measurement Programme At MSW Incinerators
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.This paper described the findings and data resulting from the German National Dioxin Measurement Programme at 11 plants with 15 incineration units. The programme's main focus was to provide answers to the question of the causes of dioxins and furans formation in the plant and to look for ways to reduce dioxin and furan emissions, including waste management measures and technical measures taken inside the plants. The investigations confirmed the finding that a major proportion of the dioxin and furan emissions is due to de novo synthesis. Two areas have to be mentioned here, the cooling zone behind the combustion chamber and the dust removal system. Significant differences in dioxin and furan concentration levels were ascertained between variations of operating parameters, e.g. much air, little air, extremely unfavourable operating conditions (i.e. start-up and shut-down without auxiliary burners) and the normal operating conditions specific to a plant. To comply the limit value of 0.1 ng I-TE m-3 it is necessary that conventional thermal treatment plants take additional measures to remove dioxins and furans from the flue gas. The measurements were carried out from 1985 to 1990. In addition, samples of fractions of household waste were analysed for their dioxins and furans
Workers and Technological Change in the United States
In this paper, we put forward a theoretical framework for understanding a positive relationship between labor laws and innovation and rigorously test it against both historical and empirical data. We show how several periods in the economic history of the United States – like the increase in slave-field hand productivity in cotton picking in the Antebellum South, the transition in the North from artisanal shops to nonmechanized factories, the increase in productivity in mechanized textile factories in the Northeast in the late Antebellum period, and the increase in productivity in sharecropping after the Civil War – can be understood, at least partially, through our theoretical framework. To build further support for the framework, we empirically analyze how change in labor laws during the early twentieth century affect patent issuance by state. And we also look at how changes in worker power, as proxied by strike activity, affected patent issuance by industry between the early twentieth century and 1980
Conditional Sum-Product Networks: Imposing Structure on Deep Probabilistic Architectures
Probabilistic graphical models are a central tool in AI; however, they are
generally not as expressive as deep neural models, and inference is notoriously
hard and slow. In contrast, deep probabilistic models such as sum-product
networks (SPNs) capture joint distributions in a tractable fashion, but still
lack the expressive power of intractable models based on deep neural networks.
Therefore, we introduce conditional SPNs (CSPNs), conditional density
estimators for multivariate and potentially hybrid domains which allow
harnessing the expressive power of neural networks while still maintaining
tractability guarantees. One way to implement CSPNs is to use an existing SPN
structure and condition its parameters on the input, e.g., via a deep neural
network. This approach, however, might misrepresent the conditional
independence structure present in data. Consequently, we also develop a
structure-learning approach that derives both the structure and parameters of
CSPNs from data. Our experimental evidence demonstrates that CSPNs are
competitive with other probabilistic models and yield superior performance on
multilabel image classification compared to mean field and mixture density
networks. Furthermore, they can successfully be employed as building blocks for
structured probabilistic models, such as autoregressive image models.Comment: 13 pages, 6 figure
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