139 research outputs found
To Duckweeds (\u3cem\u3eLandoltia punctata\u3c/em\u3e), Nanoparticulate Copper Oxide is More Inhibitory than the Soluble Copper in the Bulk Solution
CuO nanoparticles (CuO-NP) were synthesized in a hydrogen diffusion flame. Particle size and morphology were characterized using scanning mobility particle sizing, Brunauer–Emmett–Teller analysis, dynamic light scattering, and transmission electron microscopy. The solubility of CuO-NP varied with both pH and presence of other ions. CuO-NP and comparable doses of soluble Cu were applied to duckweeds, Landoltia punctata. Growth was inhibited 50% by either 0.6 mg L−1 soluble copper or by 1.0 mg L−1 CuO-NP that released only 0.16 mg L−1 soluble Cu into growth medium. A significant decrease of chlorophyll was observed in plants stressed by 1.0 mg L−1 CuO-NP, but not in the comparable 0.2 mg L−1 soluble Cu treatment. The Cu content of fronds exposed to CuO-NP is four times higher than in fronds exposed to an equivalent dose of soluble copper, and this is enough to explain the inhibitory effects on growth and chlorophyll content
Compositional Embeddings Using Complementary Partitions for Memory-Efficient Recommendation Systems
Modern deep learning-based recommendation systems exploit hundreds to
thousands of different categorical features, each with millions of different
categories ranging from clicks to posts. To respect the natural diversity
within the categorical data, embeddings map each category to a unique dense
representation within an embedded space. Since each categorical feature could
take on as many as tens of millions of different possible categories, the
embedding tables form the primary memory bottleneck during both training and
inference. We propose a novel approach for reducing the embedding size in an
end-to-end fashion by exploiting complementary partitions of the category set
to produce a unique embedding vector for each category without explicit
definition. By storing multiple smaller embedding tables based on each
complementary partition and combining embeddings from each table, we define a
unique embedding for each category at smaller memory cost. This approach may be
interpreted as using a specific fixed codebook to ensure uniqueness of each
category's representation. Our experimental results demonstrate the
effectiveness of our approach over the hashing trick for reducing the size of
the embedding tables in terms of model loss and accuracy, while retaining a
similar reduction in the number of parameters.Comment: 11 pages, 7 figures, 1 tabl
De novo SNP discovery and genetic linkage mapping in poplar using restriction site associated DNA and whole-genome sequencing technologies
Detailed information on genetic distance and linkage phase between adjacent SNP markers on the genetic linkage map of the female P. deltoides ‘I-69’. The corresponding identical SNPs identified based on the P. trichocarpa reference genome are also included. (XLS 452 kb
The Stem Cell Niche in Leaf Axils Is Established by Auxin and Cytokinin in Arabidopsis
A Correlation Attack on Full SNOW-V and SNOW-Vi
In this paper, a method for searching correlations between the binary stream of Linear Feedback Shift Register (LFSR) and the keystream of SNOW-V and SNOW-Vi is presented based on the technique of approximation to composite functions. With the aid of the linear relationship between the four taps of LFSR input into Finite State Machine (FSM) at three consecutive clocks, we present an automatic search model based on the SAT/SMT technique and search out a series of linear approximation trails with high correlation. By exhausting the intermediate masks, we find a binary linear approximation with a correlation . Using such approximation, we propose a correlation attack on SNOW-V with an expected time complexity , a memory complexity and keystream words generated by the same key and Initial Vector (IV). For SNOW-Vi, we provide a binary linear approximation with the same correlation and mount a correlation attack with the same complexity as that of SNOW-V. To the best of our knowledge, this is the first known attack on full SNOW-V and SNOW-Vi, which is better than the exhaustive key search with respect to time complexity. The results indicate that neither SNOW-V nor SNOW-Vi can guarantee the 256-bit security level if we ignore the design constraint that the maximum length of keystream for a single pair of key and IV is less than
The Stem Cell Niche in Leaf Axils Is Established by Auxin and Cytokinin in Arabidopsis
Plants differ from most animals in their ability to initiate new cycles of growth and development, which relies on the establishment and activity of branch meristems harboring new stem cell niches. In seed plants, this is achieved by axillary meristems, which are established in the axil of each leaf base and develop into lateral branches. Here, we describe the initial processes of Arabidopsis thaliana axillary meristem initiation. Using reporter gene expression analysis, we find that axillary meristems initiate from leaf axil cells with low auxin through stereotypical stages. Consistent with this, ectopic overproduction of auxin in the leaf axil efficiently inhibits axillary meristem initiation. Furthermore, our results demonstrate that auxin efflux is required for the leaf axil auxin minimum and axillary meristem initiation. After lowering of auxin levels, a subsequent cytokinin signaling pulse is observed prior to axillary meristem initiation. Genetic analysis suggests that cytokinin perception and signaling are both required for axillary meristem initiation. Finally, we show that cytokinin overproduction in the leaf axil partially rescue axillary meristem initiation-deficient mutants. These results define a mechanistic framework for understanding axillary meristem initiation
Identification of Ah Receptor Agonists in Soil of E-waste Recycling Sites from Taizhou Area in China
Towards Predicting Equilibrium Distributions for Molecular Systems with Deep Learning
Advances in deep learning have greatly improved structure prediction of
molecules. However, many macroscopic observations that are important for
real-world applications are not functions of a single molecular structure, but
rather determined from the equilibrium distribution of structures. Traditional
methods for obtaining these distributions, such as molecular dynamics
simulation, are computationally expensive and often intractable. In this paper,
we introduce a novel deep learning framework, called Distributional Graphormer
(DiG), in an attempt to predict the equilibrium distribution of molecular
systems. Inspired by the annealing process in thermodynamics, DiG employs deep
neural networks to transform a simple distribution towards the equilibrium
distribution, conditioned on a descriptor of a molecular system, such as a
chemical graph or a protein sequence. This framework enables efficient
generation of diverse conformations and provides estimations of state
densities. We demonstrate the performance of DiG on several molecular tasks,
including protein conformation sampling, ligand structure sampling,
catalyst-adsorbate sampling, and property-guided structure generation. DiG
presents a significant advancement in methodology for statistically
understanding molecular systems, opening up new research opportunities in
molecular science.Comment: 80 pages, 11 figure
HemoglobinA1c Is a Risk Factor for Changes of Bone Mineral Density: A Mendelian Randomization Study
BackgroundAs a valuable blood glucose measurement, HemoglobinA1c (HbA1c) is of great clinical value for diabetes. However, in previous observational studies, studies on its effect on bone mineral density (BMD) have different results. This study aimed to use Mendelian randomization (MR) to assess the effect of HbA1c on bone mineral density and fracture risk, and try to further explore whether this association was achieved through glycemic or non-glycemic factors.MethodsTake HbA1c measurement as exposure, and BMD estimated from quantitative heel ultrasounds (eBMD) and bone fractures as outcomes. Two-Sample MR Analysis was conducted to assess the causal effect of HbA1C on heel BMD and risk fracture. Then, we performed the analysis using two subsets of these variants, one related to glycemic measurement and the other to erythrocyte indices.ResultsGenetically increased HbA1C was associated with the lower heel eBMD [odds ratio (OR) 0.91 (95% CI 0.87, 0.96) per %-unit, P = 3 × 10−4(IVW)]. Higher HbA1C was associated with lower heel eBMD when using only erythrocytic variants [OR 0.87 (0.82, 0.93), P=2× 10−5(IVW)]; However, when using only glycemic variants, this casual association does not hold. In further MR analysis, we test the association of erythrocytic traits with heel eBMD.ConclusionOur study revealed the significant causal effect of HbA1c on eBMD, and this causal link might achieve through non-glycemic pathways (erythrocytic indices)
Remarkable Reduction of MAP2 in the Brains of Scrapie-Infected Rodents and Human Prion Disease Possibly Correlated with the Increase of Calpain
Microtubule-associated protein 2 (MAP2) belongs to the family of heat stable MAPs, which takes part in neuronal morphogenesis, maintenance of cellular architecture and internal organization, cell division and cellular processes. To obtain insight into the possible alteration and the role of MAP2 in transmissible spongiform encephalopathies (TSEs), the MAP2 levels in the brain tissues of agent 263K-infected hamsters and human prion diseases were evaluated. Western blots and IHC revealed that at the terminal stages of the diseases, MAP2 levels in the brain tissues of scrapie infected hamsters, a patient with genetic Creutzfeldt-Jakob disease (G114V gCJD) and a patient with fatal familial insomnia (FFI) were almost undetectable. The decline of MAP2 was closely related with prolonged incubation time. Exposure of SK-N-SH neuroblastoma cell line to cytotoxic PrP106-126 peptide significantly down-regulated the cellular MAP2 level and remarkably disrupted the microtubule structure, but did not alter the level of tubulin. Moreover, the levels of calpain, which mediated the degradation of a broad of cytoskeletal proteins, were significantly increased in both PrP106-126 treated SK-N-SH cells and brain tissues of 263K prion-infected hamsters. Our data indicate that the decline of MAP2 is a common phenomenon in TSEs, which seems to occur at an early stage of incubation period. Markedly increased calpain level might contribute to the reduction of MAP2
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