262 research outputs found
Semi-analytical stochastic study of radionuclide transport in the saturated zone below Yucca Mountain
The objective of this study is to predict radionuclide solute transport process in the saturated zone below the Yucca Mountain project area. Based on a stochastic perturbation approach, a numerical method of moments has been developed and used to predict the mean, variance and upper bound of the radionuclide mass flux through a control plane 5-km downstream of the footprint of the repository. This study enhances the analysis of the effect of mediumās heterogeneity on solute transport prediction, especially on prediction uncertainty
On stochastic modeling of groundwater flow and solute transport in multi-scale heterogeneous formations
Brain Imaging of Nicotinic Receptors in Alzheimer's Disease
Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand-gated ion channels which are widely distributed in the human brain. Several lines of evidence suggest that two major subtypes (Ī±4Ī²2 and Ī±7) of nAChRs play an important role in the pathophysiology of Alzheimer's disease (AD). Postmortem studies demonstrated alterations in the density of these subtypes of nAChRs in the brain of patients with AD. Currently, nAChRs are one of the most attractive therapeutic targets for AD. Therefore, several researchers have made an effort to develop novel radioligands that can be used to study quantitatively the distribution of these two subtypes in the human brain with positron emission tomography (PET) and single-photon emission computed tomography (SPECT). In this paper, we discuss the current topics on in vivo imaging of two subtypes of nAChRs in the brain of patients with AD
Association Between the Ratio of Ovarian Stimulation Duration to Original Follicular Phase Length and In Vitro Fertilization Outcomes: A Novel Index to Optimise Clinical Trigger Time
The duration of ovarian stimulation which is largely dependent on the ovarian response to hormonal stimulation may influence in vitro fertilization (IVF) outcomes. Menstrual cycle length is potentially a good indicator of ovarian reserve and can predict ovarian response. Ovarian stimulation and the follicular phase of the menstrual cycle are both processes of follicular development. There is no published research to predict the duration of ovarian stimulation based on the length of the menstrual cycle. Our retrospective cohort study included 6110 women with regular menstrual cycles who underwent their first IVF treatment between January 2015 and October 2020. Cycles were classified according to quartiles of the ratio of ovarian stimulation duration to original follicular phase length (OS/FP). Multivariate generalized linear models were applied to assess the association between OS/FP and IVF outcomes. The odds ratio (OR) or relative risk (RR) was estimated for each quartile with the lowest quartile as the comparison group. OS/FP of 0.67 to 0.77 had more retrieved and mature oocytes (adjusted RR 1.11, 95% confidence interval [CI] 1.07ā1.15, p for trend = 0.001; adjusted RR 1.14, 95% CI 1.09ā1.19, p for trend = 0.001). OS/FP of 0.67 to 0.77 showed the highest rate of fertilization (adjusted OR 1.11, 95% CI 1.05ā1.17, p for trend = 0.001). OS/FP > 0.77 had the lowest rate of high-quality blastocyst formation (adjusted OR 0.81, 95% CI 0.71ā0.93, p for trend = 0.01). No apparent association was noted between OS/FP and clinical pregnancy, live birth, or early miscarriage rate. In conclusion, OS/FP has a significant effect on the number of oocytes, fertilization rate, and high-quality blastocyst formation rate. MCL could be used to predict the duration of ovarian stimulation with an OS/FP of 0.67 to 0.77, which provides a new indicator for the individualized clinical optimization of the trigger time
Numerical solutions of time-space fractional advection-dispersion equations
Summary This paper establishes a difference approximation on time-space fractional advectiondispersion equations. Based on the difference approximation an ideal numerical example has been solved, and the result is compared with the one of the rigorous time fractional advection-dispersion equation and the rigorous space fractional advection-dispersion equation respectively. The results show: when time fractional order parameter Ī³=1 or space fractional order parameter Ī±=2, the numerical calculation result of the time-space fractional advection-dispersion equations is in accordance with that of the rigorous time fractional advection-dispersion equation or the rigorous space fractional advection-dispersion equation. The variation law of the result with parameter is also similar to them, that is when Ī³ is smaller, diffusion is slower; when Ī± is smaller, diffusion is faster. The simulation calculation for a practical example indicates that time-space fractional advection-dispersion equations can simulate the skewness and the tail of anomalous diffusion. This paper provides a efficient tool for the research of fractional advection-dispersion equations
DocStormer: Revitalizing Multi-Degraded Colored Document Images to Pristine PDF
For capturing colored document images, e.g. posters and magazines, it is
common that multiple degradations such as shadows, wrinkles, etc., are
simultaneously introduced due to external factors. Restoring multi-degraded
colored document images is a great challenge, yet overlooked, as most existing
algorithms focus on enhancing color-ignored document images via binarization.
Thus, we propose DocStormer, a novel algorithm designed to restore
multi-degraded colored documents to their potential pristine PDF. The
contributions are: firstly, we propose a "Perceive-then-Restore" paradigm with
a reinforced transformer block, which more effectively encodes and utilizes the
distribution of degradations. Secondly, we are the first to utilize GAN and
pristine PDF magazine images to narrow the distribution gap between the
enhanced results and PDF images, in pursuit of less degradation and better
visual quality. Thirdly, we propose a non-parametric strategy, PFILI, which
enables a smaller training scale and larger testing resolutions with acceptable
detail trade-off, while saving memory and inference time. Fourthly, we are the
first to propose a novel Multi-Degraded Colored Document image Enhancing
dataset, named MD-CDE, for both training and evaluation. Experimental results
show that the DocStormer exhibits superior performance, capable of revitalizing
multi-degraded colored documents into their potential pristine digital
versions, which fills the current academic gap from the perspective of method,
data, and task
Effect of Maize (Zea mays L.) Plant-Type on Yield and Photosynthetic Characters of Sweet Potato (Ipomoea balatas L.) in Intercropping System
Sweet potato/maize relay-cropping mode is considered as the main farming practices of dry land in Southwest China. Although relay-cropping would cause the reduction of fresh tuber yield, it still remained unclear that the reason was shade resulted from maize or genotype of sweet potato. The present work aims at exploring the effects of maize (Zea mays L.) plant-type on photosynthetic physiology and yield of sweet potato (Ipomoea balatas L.) in relay-cropping system. Besides, three plant-types maize cultivars including compact, semi-compact and expanded type were used for relay-cropping with different sweet potato cultivars (āYushu-2ā, āYushu-6ā and āNanshu-88ā) in field. The results showed that the photosynthetically active radiation (PAR) was declined with the increase of expansion of maize plant-type, which decreased by 77.5%, 80.1% and 82.1% respectively. When relay-cropped with extended maize, the yield reduction rate of sweet potato was the highest (67%). The shade-resistance of different genotype of sweet potatoes was different, and the yield reduction rate of āYushu-2ā was the lowest (37.01%). Through conducting correlations analysis, it showed that fresh tuber yield had significant positive correlation with Effective Quantum Yield (Y(II)) and significant negative correlation with Non Photochemical Quenching Coefficient (NPQ). In terms of āYushu-2ā, the proportion of heat dissipation was the lowest, and its light quantum efficiency was higher than others. As a result, its reduction rate of yield was lower than the other two. We suggested that compact maize cultivar relay-cropping with strong shade-resistance sweet potato cultivar should be mainly applied in practice of sweet potato
Bayesian convolutional neural networks for predicting the terrestrial water storage anomalies during GRACE and GRACE-FO gap
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