991 research outputs found
Bivariate functions with low -differential uniformity
Starting with the multiplication of elements in which is
consistent with that over , where is a prime power, via
some identification of the two environments, we investigate the
-differential uniformity for bivariate functions .
By carefully choosing the functions and , we present several
constructions of bivariate functions with low -differential uniformity. Many
PN and APN functions can be produced from our constructions.Comment: Low -differential uniformity, perfect and almost perfect
-nonlinearity, the bivariate functio
Neural-Symbolic Recursive Machine for Systematic Generalization
Despite the tremendous success, existing machine learning models still fall
short of human-like systematic generalization -- learning compositional rules
from limited data and applying them to unseen combinations in various domains.
We propose Neural-Symbolic Recursive Machine (NSR) to tackle this deficiency.
The core representation of NSR is a Grounded Symbol System (GSS) with
combinatorial syntax and semantics, which entirely emerges from training data.
Akin to the neuroscience studies suggesting separate brain systems for
perceptual, syntactic, and semantic processing, NSR implements analogous
separate modules of neural perception, syntactic parsing, and semantic
reasoning, which are jointly learned by a deduction-abduction algorithm. We
prove that NSR is expressive enough to model various sequence-to-sequence
tasks. Superior systematic generalization is achieved via the inductive biases
of equivariance and recursiveness embedded in NSR. In experiments, NSR achieves
state-of-the-art performance in three benchmarks from different domains: SCAN
for semantic parsing, PCFG for string manipulation, and HINT for arithmetic
reasoning. Specifically, NSR achieves 100% generalization accuracy on SCAN and
PCFG and outperforms state-of-the-art models on HINT by about 23%. Our NSR
demonstrates stronger generalization than pure neural networks due to its
symbolic representation and inductive biases. NSR also demonstrates better
transferability than existing neural-symbolic approaches due to less
domain-specific knowledge required
A HINT from Arithmetic: On Systematic Generalization of Perception, Syntax, and Semantics
Inspired by humans' remarkable ability to master arithmetic and generalize to
unseen problems, we present a new dataset, HINT, to study machines' capability
of learning generalizable concepts at three different levels: perception,
syntax, and semantics. In particular, concepts in HINT, including both digits
and operators, are required to learn in a weakly-supervised fashion: Only the
final results of handwriting expressions are provided as supervision. Learning
agents need to reckon how concepts are perceived from raw signals such as
images (i.e., perception), how multiple concepts are structurally combined to
form a valid expression (i.e., syntax), and how concepts are realized to afford
various reasoning tasks (i.e., semantics). With a focus on systematic
generalization, we carefully design a five-fold test set to evaluate both the
interpolation and the extrapolation of learned concepts. To tackle this
challenging problem, we propose a neural-symbolic system by integrating neural
networks with grammar parsing and program synthesis, learned by a novel
deduction--abduction strategy. In experiments, the proposed neural-symbolic
system demonstrates strong generalization capability and significantly
outperforms end-to-end neural methods like RNN and Transformer. The results
also indicate the significance of recursive priors for extrapolation on syntax
and semantics.Comment: Preliminary wor
Uloga deplecije glutationa u aktivaciji Nrf2/ARE deltametrinom u Ŕtakorskim PC12-stanicama feokromocitoma
Transcription factor NF-E2-related factor 2 (Nrf2) is important for cell protection against chemical-induced oxidative stress. Previously, we have reported that in PC12 cells, Nrf2 can be triggered by deltamethrin (DM), a commonly used pyrethroid insecticide. Molecular mechanisms behind Nrf2 activation by DM are still unclear. Here we studied the effects of cell glutathione (GSH) depletion on Nrf2 activation by DM. We found that DM enhanced Nrf2 expression at the mRNA and protein levels and increased nuclear Nrf2 levels. Activation of Nrf2 was associated with activation of its downstream targets, such as heme oxygenase-1 (HO-1) and glutamate cysteine ligase catalytic subunit (GCLC). In contrast, DL-buthionine-[S,R]- sulfoximine (BSO), a known GSH-depleting agent, did not increase Nrf2 protein expression or cause its nuclear accumulation. However, pre-treatment with BSO triggered mRNA expression of HO-1 and GCLC. Furthermore, BSO pre-treatment suppressed DM-induced Nrf2 upregulation and activation and lowered mRNA expression of HO-1 and GCLC upon DM treatment. These data demonstrate that GSH depletion is not necessary for the activation of Nrf2/ARE by DM in PC12 cells, and that GCLC and HO-1 expression can increase through other signalling pathways.Transkripcijski Äimbenik 2 povezan s NF-E2 (Nrf2) važan je za zaÅ”titu stanice od oksidacijskog stresa uzrokovanog kemijskim spojevima. U prijaÅ”njem smo istraživanju utvrdili da Äesto rabljeni piretroidni insekticid deltametrin aktivira Nrf2 u Å”takorskim PC12-stanicama feokromocitoma. JoÅ” meÄutim nisu jasni molekularni mehanizmi te aktivacije. U ovome smo istraživanju željeli utvrditi ulogu deplecije staniÄnoga glutationa (GSH) u aktivaciji Nrf2 od strane DM-a. DM je pojaÄao ekspresiju Nrf2 u mRNA te povisio razinu proteina i razinu Nrf2 u jezgri. Aktivacija Nrf2 bila je povezana s nizvodnom aktivacijom hemoksigenaze 1 (HO-1) i katalitiÄke podjedinice glutamat cistein ligaze (GCLC). DL-butionin-[S,R]-sulfoksimin (BSO), za koji se zna da dovodi do deplecije GSH, nije meÄutim poveÄao ekspresiju Nrf2-proteina niti doveo do njegova nakupljanja u staniÄnoj jezgri. Prethodna primjena BSO aktivirala je meÄutim ekspresiju HO-1 i GCLC u mRNA. Usto je suprimirala djelovanje DM-a na aktivaciju i regulaciju Nrf2 te smanjila ekspresiju HO-1 i GCLC u mRNA nakon primjene DM-a. Ova saznanja govore da deplecija GSH nije nuždan mehanizam za aktivaciju Nrf2/ARE od strane DM-a u PC12-stanica te da do poveÄane ekspresije GCLC i HO-1 može doÄi drugim signalnim putovima
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