132 research outputs found
Games and Argumentation: Time for a Family Reunion!
The rule "defeated(X) attacks(Y,X), defeated(Y)" states
that an argument is defeated if it is attacked by an argument that is not
defeated. The rule "win(X) move(X,Y), win(Y)" states that
in a game a position is won if there is a move to a position that is not won.
Both logic rules can be seen as close relatives (even identical twins) and both
rules have been at the center of attention at various times in different
communities: The first rule lies at the core of argumentation frameworks and
has spawned a large family of models and semantics of abstract argumentation.
The second rule has played a key role in the quest to find the "right"
semantics for logic programs with recursion through negation, and has given
rise to the stable and well-founded semantics. Both semantics have been widely
studied by the logic programming and nonmonotonic reasoning community. The
second rule has also received much attention by the database and finite model
theory community, e.g., when studying the expressive power of query languages
and fixpoint logics. Although close connections between argumentation
frameworks, logic programming, and dialogue games have been known for a long
time, the overlap and cross-fertilization between the communities appears to be
smaller than one might expect. To this end, we recall some of the key results
from database theory in which the win-move query has played a central role,
e.g., on normal forms and expressive power of query languages. We introduce
some notions that naturally emerge from games and that may provide new
perspectives and research opportunities for argumentation frameworks. We
discuss how solved query evaluation games reveal how- and why-not provenance of
query answers. These techniques can be used to explain how results were derived
via the given query, game, or argumentation framework.Comment: Fourth Workshop on Explainable Logic-Based Knowledge Representation
(XLoKR), Sept 2, 2023. Rhodes, Greec
MAIDR: Making Statistical Visualizations Accessible with Multimodal Data Representation
This paper investigates new data exploration experiences that enable blind
users to interact with statistical data visualizationsbar plots, heat maps,
box plots, and scatter plotsleveraging multimodal data representations. In
addition to sonification and textual descriptions that are commonly employed by
existing accessible visualizations, our MAIDR (multimodal access and
interactive data representation) system incorporates two additional modalities
(braille and review) that offer complementary benefits. It also provides blind
users with the autonomy and control to interactively access and understand data
visualizations. In a user study involving 11 blind participants, we found the
MAIDR system facilitated the accurate interpretation of statistical
visualizations. Participants exhibited a range of strategies in combining
multiple modalities, influenced by their past interactions and experiences with
data visualizations. This work accentuates the overlooked potential of
combining refreshable tactile representation with other modalities and elevates
the discussion on the importance of user autonomy when designing accessible
data visualizations.Comment: Accepted to CHI 2024. Source code is available at
https://github.com/xability/maid
Generalized Activation via Multivariate Projection
Activation functions are essential to introduce nonlinearity into neural
networks, with the Rectified Linear Unit (ReLU) often favored for its
simplicity and effectiveness. Motivated by the structural similarity between a
shallow Feedforward Neural Network (FNN) and a single iteration of the
Projected Gradient Descent (PGD) algorithm, a standard approach for solving
constrained optimization problems, we consider ReLU as a projection from R onto
the nonnegative half-line R+. Building on this interpretation, we extend ReLU
by substituting it with a generalized projection operator onto a convex cone,
such as the Second-Order Cone (SOC) projection, thereby naturally extending it
to a Multivariate Projection Unit (MPU), an activation function with multiple
inputs and multiple outputs. We further provide mathematical proof establishing
that FNNs activated by SOC projections outperform those utilizing ReLU in terms
of expressive power. Experimental evaluations on widely-adopted architectures
further corroborate MPU's effectiveness against a broader range of existing
activation functions
Characterization of four vaccine-related polioviruses including two intertypic type 3/type 2 recombinants associated with aseptic encephalitis
Temperature sensitivity of 4 poliovirus type 3 isolates. (DOC 31 kb
Anti-aging mechanism and effect of treatment with raw and wine-steamed Polygonatum sibiricum on D-galactose-induced aging in mice by inhibiting oxidative stress and modulating gut microbiota
BackgroundPolygonatum sibiricum (PS) is a traditional Chinese medicine (TCM) first recorded in Mingyi Bielu. The book documents that PS can nourish five internal organs, be taken for a long time, relax the body and prolong lifespan. Presently, PS is widely used in TCM to prevent premature graying of hair. Based on TCM theory and clinical trials, the wine steaming processed product from PS provides a better effect. However, no published study has elucidated the anti-aging mechanism.PurposeThe study aim was to investigate the anti-aging mechanism of PS and its wine steaming processed product in mice, specifically focusing on the effect of D-galactose (D-gal) surrounding the intestinal flora and the Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2-antioxidant response elements (Keap1/Nrf2/ARE) pathway.MethodsThe chemical components in Raw PS (RPS) and Wine-steamed PS (WPS) were identified by ultra-performance liquid chromatography–hybrid quadrupole-Orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap HRMS). An aging model using Kunming mice was established through intraperitoneally injected D-gal. Concentrations of RPS and WPS at 5, 10, or 15 g/kg/day levels were administered intragastrically, respectively. The body weight, liver and spleen indexes, superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA) activities in serum and brain tissue were recorded. Hematoxylin and eosin (HE) stained brain tissue was histopathologically examined. The expressions of Keap1, Nrf2 and heme oxygenase 1 (HO-1) in the brain tissue at the mRNA and protein levels were respectively detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB). Moreover, an Illumina Hiseq platform was used for 16S ribosomal RNA (16S rRNA) high-throughput sequencing to evaluate the proportions of intestinal flora in aging mice.ResultsThe proportions of saccharides, flavonoids, and triterpene acids were different between RPS and WPS. In the aging model mice, WPS outperformed RPS in improving body weight and mental state by increasing the spleen index, SOD and GSH-PX activities, decreasing the liver index and MDA activities, and restoring the histopathological morphology in D-gal-induced aging mice. At the mRNA levels, RPS and WPS significantly reduced the expression of Keap1 and increased the expressions of Nrf2 and HO-1. The trend in protein expressions was similar to that of the mRNA results, and WPS had a stronger effect than RPS. Fecal microbiota analysis showed that RPS and WPS restored intestinal microbiota proportions to normal levels.ConclusionThe results demonstrated that PS and its WPS had a positive effect in relieving oxidative stress in aging mice. WPS outperformed RPS, which might be related to the activation of the Keap1/Nrf2/ARE pathway and regulation of intestinal flora
Impacts of plastic film mulching on crop yields, soil water, nitrate, and organic carbon in Northwestern China: A meta-analysis
In order to increase crop yield in semi-arid and arid areas, plastic film mulching (PFM) is widely used in Northwestern China. To date, many studies have addressed the effects of PFM on soil physical and biochemical properties in rain-fed agriculture in Northwestern China, but the findings of different studies are often contradictory. Therefore, a comprehensive review of the impacts of PFM on soil water content, soil nutrients and food production is needed. We compiled the results of 1278 observations to evaluate the overall effects of PFM on soil water content, the distribution of nitrate and soil organic carbon, and crop yield in rain-fed agriculture in
Northwestern China. Our results showed that PFM increased soil moisture and nitrate concentration in topsoils (0–20 cm) by 12.9% and 28.2%, respectively, but slightly decreased (1.8%) soil organic carbon (SOC) content in the 0–10 cm soil layer. PFM significantly increased grain yields by 43.1%, with greatest effect in spring maize (79.4%). When related to cumulative precipitation during the crop growing season, yield increase from PFM was greatest (72.8%) at 200–300 mm, which was attributed to the large increase for spring maize and potato, implying that crop zoning would be beneficial for PFM in this region. When related to N application rate, crop yields benefited most from PFM (80.2%) at 200–300 kg/ha. A cost-benefit analysis indicated that PFM increased economic return by an average of 29.5%, with the best improvement for spring maize (71.1%) and no increase for spring wheat. In conclusion, PFM can significantly increase crop yield and economic return (especially for spring maize) in rain-fed agriculture areas of Northwestern China. Crop zoning is recommended for PFM to achieve the largest economic benefit. However, full account needs to be taken of the environmental impacts relating to N loss, SOC depletion and film pollution to evaluate the sustainability of PFM systems and further research is required to quantify and mitigate these impacts
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Circularly Polarized Antenna Array Fed by Air-Bridge Free CPW-Slotline Network
A novel design of 1×2 and 2×2 circularly polarized (CP) microstrip patch antenna arrays is presented in this paper. The two CP antenna arrays are fed by sequentially rotated coplanar waveguide (CPW) to slotline networks and are processed on 1 mm thick single-layer FR4 substrates. Both of the two arrays are low-profile and lightweight. An air-bridge free CPW-slotline power splitter is appropriately designed to form the feeding networks and realize the two CP antenna arrays. The mechanism of circular polarization in this design is explained. The simulated and measured impedance bandwidths as well as the 3 dB axial ratio bandwidths and the radiation patterns of the two proposed antenna arrays are presented. This proposed design can be easily extended to form a larger plane array with good performance owing to its simple structure
- …