643 research outputs found
Propagating functional dependencies with conditions
The dependency propagation problem is to determine, given a view defined on data sources and a set of dependencies on the sources, whether another dependency is guaranteed to hold on the view. This paper investigates dependency propagation for recently proposed conditional functional dependencies (CFDs). The need for this study is evident in data integration, exchange and cleaning since dependencies on data sources often only hold
conditionally
on the view. We investigate dependency propagation for views defined in various fragments of relational algebra, CFDs as view dependencies, and for source dependencies given as either CFDs or traditional functional dependencies (FDs). (a) We establish lower and upper bounds,
all matching
, ranging from PTIME to undecidable. These not only provide the
first
results for CFD propagation, but also extend the classical work of FD propagation by giving new complexity bounds in the presence of finite domains. (b) We provide the first algorithm for computing a minimal cover of
all
CFDs propagated via SPC views; the algorithm has the same complexity as one of the most efficient algorithms for computing a cover of FDs propagated via a projection view, despite the increased expressive power of CFDs and SPC views. (c) We experimentally verify that the algorithm is efficient.
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Forecast on Energy Demand of Road Transportation in China
AbstractTo some extent, there are some uncertainties factors in forecasting energy demand of road transportation. Scientific forecasting China's energy demand of road transportation is a key for make long-term development plans of the nation's road transportation, and relevant policies of environmental protection and energy-saving. Basing on the energy demand of China's road transportation, considering the factors average fuel consumption of singleautomobile and the workload of road transportation, the paper does a comprehensive forecasting for China's energy demand of transportation in the future. The result is that in 2030, the energy demand of road transportation will amount to 250 million tons, which is 1.4 times that of 2020, and 2.3 times that of 2010. The significant increase of energy demand will inevitably bring great pressure to resources of energy and environmental protection, so the implementation of scientific development concept, saving resources and protecting the environment and adopting sustainable development policy will be the objective requirements for highway transportation development of China in the future
The role of sensory uncertainty in simple contour integration
Perceptual organization is the process of grouping scene elements into whole entities. A classic example is contour integration, in which separate line segments are perceived as continuous contours. Uncertainty in such grouping arises from scene ambiguity and sensory noise. Some classic Gestalt principles of contour integration, and more broadly, of perceptual organization, have been re-framed in terms of Bayesian inference, whereby the observer computes the probability that the whole entity is present. Previous studies that proposed a Bayesian interpretation of perceptual organization, however, have ignored sensory uncertainty, despite the fact that accounting for the current level of perceptual uncertainty is one the main signatures of Bayesian decision making. Crucially, trial-by-trial manipulation of sensory uncertainty is a key test to whether humans perform near-optimal Bayesian inference in contour integration, as opposed to using some manifestly non-Bayesian heuristic. We distinguish between these hypotheses in a simplified form of contour integration, namely judging whether two line segments separated by an occluder are collinear. We manipulate sensory uncertainty by varying retinal eccentricity. A Bayes-optimal observer would take the level of sensory uncertainty into account-in a very specific way-in deciding whether a measured offset between the line segments is due to non-collinearity or to sensory noise. We find that people deviate slightly but systematically from Bayesian optimality, while still performing "probabilistic computation" in the sense that they take into account sensory uncertainty via a heuristic rule. Our work contributes to an understanding of the role of sensory uncertainty in higher-order perception. Author summary Our percept of the world is governed not only by the sensory information we have access to, but also by the way we interpret this information. When presented with a visual scene, our visual system undergoes a process of grouping visual elements together to form coherent entities so that we can interpret the scene more readily and meaningfully. For example, when looking at a pile of autumn leaves, one can still perceive and identify a whole leaf even when it is partially covered by another leaf. While Gestalt psychologists have long described perceptual organization with a set of qualitative laws, recent studies offered a statistically-optimal-Bayesian, in statistical jargon-interpretation of this process, whereby the observer chooses the scene configuration with the highest probability given the available sensory inputs. However, these studies drew their conclusions without considering a key actor in this kind of statistically-optimal computations, that is the role of sensory uncertainty. One can easily imagine that our decision on whether two contours belong to the same leaf or different leaves is likely going to change when we move from viewing the pile of leaves at a great distance (high sensory uncertainty), to viewing very closely (low sensory uncertainty). Our study examines whether and how people incorporate uncertainty into contour integration, an elementary form of perceptual organization, by varying sensory uncertainty from trial to trial in a simple contour integration task. We found that people indeed take into account sensory uncertainty, however in a way that subtly deviates from optimal behavior.Peer reviewe
Abietic acid attenuates LPS-induced acute lung injury by restoring Th17/Treg balance
Purpose: To investigate the mechanism of action and effects of abietic acid (AA) in a mouse acute lung injury (ALI) model.
Methods: A mouse ALI model was established by lipopolysaccharide (LPS) induction. Lung tissues were examined for histological alterations and scored based on the degree of injury. Myeloperoxidase (MPO), IL-6, IL-1β, and TNF-α levels were measured by enzyme-linked immunosorbent assay (ELISA) while the numbers of Th17 and Treg cells were assessed by immunofluorescence. Protein expression levels of p-STAT3, p-STAT5, RORrt, and FOXP3 were analyzed by immunoblot assay. Expression of peroxisome proliferator-activated receptor γ (PPARγ) was assessed by immunoblot.
Results: AA ameliorated LPS-induced lung injury in mice. Furthermore, AA ameliorated LPS-induced pneumonia in mice (p < 0.05) and restored Th17/Treg balance and Th17/Treg transcription factor expression that was altered by LPS induction. AA also activated PPARγ expression to restore Th17/Treg balance (p < 0.05).
Conclusion: The results indicate that AA attenuates LPS-induced ALI in mice by restoring Th17/Treg balance. Thus, AA is a potential drug for the management of ALI; however, AA must first be evaluated in clinical studies
Total flavonoids from Ganshanbian (Herba Hyperici Attenuati) effect the expression of CaL-α1C and KATP-Kir6.1 mRNA of the myocardial cell membrane in myocardial ischemia-reperfusion arrhythmia rats
AbstractObjectiveTo observe the impact of total flavonoids from Ganshanbian (Herba Hyperici Attenuati) on the expression of vascular smooth muscle membrane L-type calcium channel alpha1 C subunit (CaL-α1C) and ATP-sensitive K+ channel (KATP)-Kir6.1 mRNA, and explore the mechanisms of the antiarrhythmic effect of Ganshanbian (Herba Hyperici Attenuati) total flavonoids.MethodsThe treatment group was fed total flavonoids from Ganshanbian (Herba Hyperici Attenuati) for 7 days by gavage with 100 mg · kg−1 · d−1. The blank control group and model control group were given the same amount of normal saline for 7 d. Arrhythmias were induced by performing a myocardial ischemia-reperfusion and electrocardiogram was observed. Reverse transcription-polymerase chain reaction was used to detect the expression of CaL-α 1Cand KATP-Kir6.1 mRNA in the myocardial cell membrane of all groups of rats.ResultsTotal flavonoids from Ganshanbian (Herba Hyperici Attenuati) can delay the appearance of myocardial ischemia reperfusion arrhythmias, shorten the duration of myocardial ischemia reperfusion arrhythmias, reduce heart rate, reduce cell membrane expression of CaL-α1C mRNA and enhance the expression of KATP-Kir6.1 mRNA in myocardial ischemia-reperfusion arrhythmic rats.ConclusionTotal flavonoids from Ganshanbian (Herba Hyperici Attenuati) can alleviate arrhythmias by affecting the expression of L-type calcium channels and ATP-sensitive K+ channels
The pathological changes in the spinal cord after dural tear with and without autologous fascia repair
Synergistic Improvement of Production, Economic Return and Sustainability in the Tea Industry through Ecological Pest Management
The use of ecological principles to manage plant pests has attracted renewed attention, but our knowledge related to the contributions of ecological pest management to social and natural sustainability is fragmented. In this study, we compared the performance and resilience of tea production and the economic benefits of tea ecological management (TEM) and tea conventional management (TCM). We show that TEM significantly improved tea biomass and quality, nutritional efficiency, and beneficial insects, but reduced seasonal variation. As a result, economic return increased by 6064/ha in the TCM mode. These results confirm that TEM is a promising production mode that can reconcile the conflict between the immediate and long-term service of agriculture. However, environmental improvements associated with organic pest control benefit society, and the government should provide adequate financial support to promote the production system
The influence of angiopoietin-like protein 3 on macrophages polarization and its effect on the podocyte EMT in diabetic nephropathy
BackgroundPodocyte injury, which involves the podocyte epithelial-mesenchymal transition (EMT) process, is a crucial factor contributing to the progression of diabetic nephropathy (DN) and proteinuria. Our study aimed to examine the protective properties of Angiopoietin-like protein 3 (Angptl3) knockout on podocyte damage and macrophage polarization in DN mice and podocytes treated with HG. Furthermore, we also sought to investigate the underlying molecular mechanism responsible for these effects.MethodsDN was induced in B6;129S5 mice through intraperitoneal injection of 40 mg/kg of streptozotocin (STZ). Subsequently, the changes in renal function, podocyte apoptosis, inflammatory factors (tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6], and interleukin-1β [IL-1β]), IL-10, TGF-β1, IL-1Ra, IL-10Ra, and nephrin were evaluated. Moreover, we investigated the mechanism underlying the role of Angptl3 in macrophages polarization, podocyte injury, podocyte EMT.ResultsOur findings revealed that Angptl3 knockout significantly attenuated STZ or HG-induced renal dysfunction and podocyte EMT. In both in vivo and in vitro studies, Angptl3 knockout led to (1) promote the transformation of M1 type macrophages into M2 type macrophages; (2) amelioration of the reduced expression of nephrin, synaptopodin, and podocin; (3) inhibition of NLRP3 inflammasome activation and release of IL-1β; and (4) regulation of α-SMA expression via the macrophage polarization. (5) After HG treatment, there was an increase in pro-inflammatory factors and foot cell damage. These changes were reversed upon Angptle knockdown.ConclusionOur study suggests that the knockout of Angptl3 alleviates podocyte EMT and podocyte injury by regulating macrophage polarization
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