Discrete observations from data which are obtained from sparse, and yet concentrated events are often observed (e.g. road accidents or murders). Traditional methods to compute summary statistics often include placing the data in discrete bins but for this type of data this approach often results in large numbers of empty bins for which no function or summary statistic can be computed. Here, a method for dealing with sparse and concentrated observations is constructed, based on a sequence of non-overlapping bins of varying size, which gives a continuous interpolation of data for computing summary statistics of the values for the data, such as the mean. The method presented here overcomes the problem which sparsity and concentration present when computing functions to represent the data. Implementation of the method presented here is facilitated via open access to the code. •A new method for computing functions over sparse and concentrated data is constructed.•The method allows straightforward functions to be computed over partitions of the data, such as the mean, but also more complicated functions, such as coefficients, ratios, correlations, regressions and others.
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http://dx.doi.org/10.1016/j.mex.2019.10.020 | DOI Listing |
J Vet Pharmacol Ther
January 2025
Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China.
The objective of this study was to implement population pharmacokinetic (PPK) of enrofloxacin (EF) in grass carp (Ctenopharyngodon idella) after a single oral administration and a single intravenous administration based on a nonlinear mixed effect model. The plasma samples collected by the sparse sampling method were detected by high-performance liquid chromatography with a fluorescent detector. The initial pharmacokinetic (PK) parameters were evaluated by reference search and the calculation of a naïve pooled method.
View Article and Find Full Text PDFChemosphere
January 2025
Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu Province, 730000, China; Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.
Peroxyacetyl Nitrate (CHC(O)ONO, PAN), a typical secondary product of photochemical reactions, is well known to be a better photochemical indicator due to the only secondary photochemical source in the troposphere. Studies on PAN pollution are sparse in northwest China, resulting in a limited understanding of photochemical pollution in recent years. Herein, the measurement of PAN, O, volatile organic compounds (VOCs), NO, other related species, and meteorological parameters were conducted from May 1 to August 31, 2022, at an urban site in Lanzhou.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Geosciences, Atmospheric Science Division, Texas Tech University, Lubbock, TX, USA; National Wind Institute, Texas Tech University, Lubbock, TX, USA. Electronic address:
Understanding the kinematics of aerosol horizontal transport and vertical mixing near the surface, within the atmospheric boundary layer (ABL), and in the overlying free troposphere (FT) is critical for various applications, including air quality and weather forecasting, aviation, road safety, and dispersion modeling. Empirical evidence of aerosol mixing processes within the ABL during synoptic-scale events over arid and semiarid regions (i.e.
View Article and Find Full Text PDFAm Heart J
January 2025
Department of Cardiology, Gødstrup Regional Hospital, Hospitalsparken 15, 7400 Herning, Denmark; Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark. Electronic address:
Background: The role of lipoprotein(a) (Lp(a)) in the risk-assessment of patients with de-novo stable chest pain is sparsely investigated. We assessed the association between Lp(a) concentration and the presence of coronary stenosis on coronary computed tomography (CT) angiography in a broad population of patients referred with stable chest pain.
Methods: Lp(a) measurements and coronary CT angiography were performed in 4,346 patients with stable chest pain and no previous history of coronary artery disease.
Comput Med Imaging Graph
January 2025
The Department of Computer and Data Science, Case Western Reserve University, Cleveland, OH, USA; The Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
A generic and versatile CT Image Reconstruction (CTIR) scheme can efficiently mitigate imaging noise resulting from inherent physical limitations, substantially bolstering the dependability of CT imaging diagnostics across a wider spectrum of patient cases. Current CTIR techniques often concentrate on distinct areas such as Low-Dose CT denoising (LDCTD), Sparse-View CT reconstruction (SVCTR), and Metal Artifact Reduction (MAR). Nevertheless, due to the intricate nature of multi-scenario CTIR, these techniques frequently narrow their focus to specific tasks, resulting in limited generalization capabilities for diverse scenarios.
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