The firm is a fundamental economic unit of contemporary human societies. Studies on the general quantitative and statistical character of firms have produced mixed results regarding their lifespans and mortality. We examine a comprehensive database of more than 25 000 publicly traded North American companies, from 1950 to 2009, to derive the statistics of firm lifespans. Based on detailed survival analysis, we show that the mortality of publicly traded companies manifests an approximately constant hazard rate over long periods of observation. This regularity indicates that mortality rates are independent of a company's age. We show that the typical half-life of a publicly traded company is about a decade, regardless of business sector. Our results shed new light on the dynamics of births and deaths of publicly traded companies and identify some of the necessary ingredients of a general theory of firms.
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http://dx.doi.org/10.1098/rsif.2015.0120 | DOI Listing |
Anal Bioanal Chem
January 2025
ICF International Contractor in support of the Office of Dietary Supplements, National Institutes of Health, Bethesda, MD, USA.
Rigorous research on the health effects of dietary supplements and related nutritional interventions requires thorough chemical characterization of complex matrices for their composition of macro- and micronutrients, botanical phytochemicals, and potential contaminants. Reference materials (RMs) with metrologically traceable values for these specific properties are ideal analytical tools to ensure requisite chemical measurements are reliable. However, identifying and comparing appropriate RMs for studying dietary ingredients and their metabolites is challenging, creating a barrier to reproducible regulatory testing and research.
View Article and Find Full Text PDFRadiol Artif Intell
January 2025
From the Department of Radiology, University Hospital, LMU Munich, Marchioninistr 15,81377 Munich, Germany (T.W., J.D., M.I.); Department of Statistics, LMU Munich, Munich, Germany (T.W., D.R.); and Munich Center for Machine Learning, Munich, Germany (T.W., J.D., D.R., M.I.).
Purpose To investigate whether the computational effort of 3D CT-based multiorgan segmentation with TotalSegmentator can be reduced via Tucker decomposition-based network compression. Materials and Methods In this retrospective study, Tucker decomposition was applied to the convolutional kernels of the TotalSegmentator model, an nnU-Net model trained on a comprehensive CT dataset for automatic segmentation of 117 anatomic structures. The proposed approach reduced the floating-point operations (FLOPs) and memory required during inference, offering an adjustable trade-off between computational efficiency and segmentation quality.
View Article and Find Full Text PDFBioinformatics
January 2025
Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina, USA.
Motivation: As nanopore technology reaches ever higher throughput and accuracy, it becomes an increasingly viable candidate for reading out DNA data storage. Nanopore sequencing offers considerable flexibility by allowing long reads, real-time signal analysis, and the ability to read both DNA and RNA. We need flexible and efficient designs that match nanopore's capabilities, but relatively few designs have been explored and many have significant inefficiency in read density, error rate, or compute time.
View Article and Find Full Text PDFFront Hum Neurosci
December 2024
Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands.
Introduction: As brain-computer interfacing (BCI) systems transition fromassistive technology to more diverse applications, their speed, reliability, and user experience become increasingly important. Dynamic stopping methods enhance BCI system speed by deciding at any moment whether to output a result or wait for more information. Such approach leverages trial variance, allowing good trials to be detected earlier, thereby speeding up the process without significantly compromising accuracy.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
School of Biological Sciences University of Hong Kong, Hong Kong, P.R. China.
The unsustainable use of wildlife is a primary driver of global biodiversity loss. No comprehensive global dataset exists on what species are in trade, their geographic origins, and trade's ultimate impacts, which limits our ability to sustainably manage trade. The United States is one of the world's largest importers of wildlife, with trade data compiled in the US Law Enforcement Management Information System (LEMIS).
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