177 research outputs found

    Punched-Card Systems and the Early Information Explosion, 1880–1945

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    At a time when Internet use is closely tracked and social networking sites supply data for targeted advertising, Lars Heide presents the first academic study of the invention that fueled today’s information revolution: the punched card. Early punched cards helped to process the United States census in 1890. They soon proved useful in calculating invoices and issuing pay slips. As demand for more sophisticated systems and reading machines increased in both the United States and Europe, punched cards served ever-larger data-processing purposes. Insurance companies, public utilities, businesses, and governments all used them to keep detailed records of their customers, competitors, employees, citizens, and enemies. The United States used punched-card registers in the late 1930s to pay roughly 21 million Americans their Social Security pensions, Vichy France used similar technologies in an attempt to mobilize an army against the occupying German forces, and the Germans in 1941 developed several punched-card registers to make the war effort—and surveillance of minorities—more effective. Heide’s analysis of these three major punched-card systems, as well as the impact of the invention on Great Britain, illustrates how different cultures collected personal and financial data and how they adapted to new technologies.This comparative study will interest students and scholars from a wide range of disciplines, including the history of technology, computer science, business history, and management and organizational studies

    Recent results in the development of band steaming for intra-row weed control

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    The recent achievements with developing band-steaming techniques for intra-row weed control in vegetables are presente

    Coordinated optimization of visual cortical maps : 2. Numerical studies

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    In the juvenile brain, the synaptic architecture of the visual cortex remains in a state of flux for months after the natural onset of vision and the initial emergence of feature selectivity in visual cortical neurons. It is an attractive hypothesis that visual cortical architecture is shaped during this extended period of juvenile plasticity by the coordinated optimization of multiple visual cortical maps such as orientation preference (OP), ocular dominance (OD), spatial frequency, or direction preference. In part (I) of this study we introduced a class of analytically tractable coordinated optimization models and solved representative examples, in which a spatially complex organization of the OP map is induced by interactions between the maps. We found that these solutions near symmetry breaking threshold predict a highly ordered map layout. Here we examine the time course of the convergence towards attractor states and optima of these models. In particular, we determine the timescales on which map optimization takes place and how these timescales can be compared to those of visual cortical development and plasticity. We also assess whether our models exhibit biologically more realistic, spatially irregular solutions at a finite distance from threshold, when the spatial periodicities of the two maps are detuned and when considering more than 2 feature dimensions. We show that, although maps typically undergo substantial rearrangement, no other solutions than pinwheel crystals and stripes dominate in the emerging layouts. Pinwheel crystallization takes place on a rather short timescale and can also occur for detuned wavelengths of different maps. Our numerical results thus support the view that neither minimal energy states nor intermediate transient states of our coordinated optimization models successfully explain the architecture of the visual cortex. We discuss several alternative scenarios that may improve the agreement between model solutions and biological observations

    Coordinated optimization of visual cortical maps : 1. Symmetry-based analysis

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    In the primary visual cortex of primates and carnivores, functional architecture can be characterized by maps of various stimulus features such as orientation preference (OP), ocular dominance (OD), and spatial frequency. It is a long-standing question in theoretical neuroscience whether the observed maps should be interpreted as optima of a specific energy functional that summarizes the design principles of cortical functional architecture. A rigorous evaluation of this optimization hypothesis is particularly demanded by recent evidence that the functional architecture of orientation columns precisely follows species invariant quantitative laws. Because it would be desirable to infer the form of such an optimization principle from the biological data, the optimization approach to explain cortical functional architecture raises the following questions: i) What are the genuine ground states of candidate energy functionals and how can they be calculated with precision and rigor? ii) How do differences in candidate optimization principles impact on the predicted map structure and conversely what can be learned about a hypothetical underlying optimization principle from observations on map structure? iii) Is there a way to analyze the coordinated organization of cortical maps predicted by optimization principles in general? To answer these questions we developed a general dynamical systems approach to the combined optimization of visual cortical maps of OP and another scalar feature such as OD or spatial frequency preference. From basic symmetry assumptions we obtain a comprehensive phenomenological classification of possible inter-map coupling energies and examine representative examples. We show that each individual coupling energy leads to a different class of OP solutions with different correlations among the maps such that inferences about the optimization principle from map layout appear viable. We systematically assess whether quantitative laws resembling experimental observations can result from the coordinated optimization of orientation columns with other feature maps

    Design of Ultra High Performance Fiber Reinforced Concrete Shells

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    Investigation and implications of spatial and temporal patterns in sex ratio data from West Greenland minke whale catches.

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    The sub-group based its deliberations on the computations set out below, which were carried out by Givens following input from sub-group members

    Seasonal variability of the warm Atlantic Water layer in the vicinity of the Greenland shelf break

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    The warmest water reaching the east and west coast of Greenland is found between 200?m and 600?m. Whilst important for melting Greenland's outlet glaciers, limited winter observations of this layer prohibit determination of its seasonality. To address this, temperature data from Argo profiling floats, a range of sources within the World Ocean Database and unprecedented coverage from marine-mammal borne sensors have been analysed for the period 2002-2011. A significant seasonal range in temperature (~1-2?°C) is found in the warm layer, in contrast to most of the surrounding ocean. The phase of the seasonal cycle exhibits considerable spatial variability, with the warmest water found near the eastern and southwestern shelf-break towards the end of the calendar year. High-resolution ocean model trajectory analysis suggest the timing of the arrival of the year's warmest water is a function of advection time from the subduction site in the Irminger Basin

    Scheduling shared continuous resources on many-cores

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    © 2017 Springer Science+Business Media New York We consider the problem of scheduling a number of jobs on m identical processors sharing a continuously divisible resource. Each job j comes with a resource requirement [InlineEquation not available: see fulltext.]. The job can be processed at full speed if granted its full resource requirement. If receiving only an x-portion of (Formula presented.), it is processed at an x-fraction of the full speed. Our goal is to find a resource assignment that minimizes the makespan (i.e., the latest completion time). Variants of such problems, relating the resource assignment of jobs to their processing speeds, have been studied under the term discrete–continuous scheduling. Known results are either very pessimistic or heuristic in nature. In this article, we suggest and analyze a slightly simplified model. It focuses on the assignment of shared continuous resources to the processors. The job assignment to processors and the ordering of the jobs have already been fixed. It is shown that, even for unit size jobs, finding an optimal solution is NP-hard if the number of processors is part of the input. Positive results for unit size jobs include a polynomial-time algorithm for any constant number of processors. Since the running time is infeasible for practical purposes, we also provide more efficient algorithm variants: an optimal algorithm for two processors and a [InlineEquation not available: see fulltext.] -approximation algorithm for m processors

    Comparison of efficacy in patients with metastatic melanoma treated with ipilimumab and nivolumab who did or did not discontinue treatment due to immune-related adverse events:A real-world data study

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    SIMPLE SUMMARY: This retrospective study of real-world patients with metastatic melanoma shows that discontinuing treatment with combination immunotherapy due to adverse events does not result in a poorer outcome compared to patients that did not discontinue due to toxicity. This is important knowledge for clinicians and patients, as discontinuing treatment may cause great anxiety for patients because they believe that it may limit the response. ABSTRACT: Immune-related adverse events (irAEs) are very prevalent when treating patients with ipilimumab and nivolumab in combination, and 30–40% of patients discontinue the treatment for this reason. It is of high clinical relevance to investigate the consequences of discontinuing the treatment early since combination therapy with ipilimumab and nivolumab is the first line of treatment for many patients with metastatic melanoma. In this follow-up study, with real-world data from the nationwide DAMMED database, we investigated whether there was a difference in progression-free survival (PFS) and overall survival (OS) for patients who discontinued or did not discontinue treatment within the first four doses of treatment due to irAEs. In total, 448 patients were treated with ipilimumab and nivolumab. Of these, 133 patients discontinued due to irAEs in the induction phase. Using the Cox proportional hazards model, there was no significant difference in PFS when comparing the group that discontinued with the group that did not discontinue. The group that discontinued had a significantly longer OS than the group that received the full length of treatment. Therefore, we conclude that there is no significant negative impact on efficacy for patients who discontinue due to irAEs in the induction phase of combination immunotherapy for metastatic melanoma

    Unmet needs in the diagnosis and treatment of dyslipidemia in the primary care setting in Germany

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    Objectives and methods: DETECT is a cross-sectional study of 55,518 unselected consecutive patients in 3188 representative primary care offices in Germany. In a random subset of 7519 patients, an extensive standardized laboratory program was undertaken. The study investigated the prevalence of cardiovascular disease, known risk factors (such as diabetes, hypertension and dyslipidemia and their co-morbid manifestation), as well as treatment patterns. The present analysis of the DETECT laboratory dataset focused on the prevalence and treatment of dyslipidemia in primary medical care in Germany. Coronary artery disease (CAD), risk categories and LDL-C target achievement rates were determined in the subset of 6815 patients according to the National Cholesterol Education Program (NCEP) ATP III Guidelines. Results: Of all patients, 54.3% had dyslipidemia. Only 54.4% of the NCEP-classified dyslipidemic patients were diagnosed as ‘dyslipidemic’ by their physicians. Only 27% of all dyslipidemic patients (and 40.7% of the recognized dyslipidemic patients) were treated with lipid-lowering medications, and 11.1% of all dyslipidemic patients (41.4% of the patients treated with lipid-lowering drugs) achieved their LDL-C treatment goals. In conclusion, 80.3% of patients in the sample with dyslipidemia went undiagnosed, un-treated or under-treated
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