Understanding Neural Network Binarization with Forward and Backward Proximal Quantizers

In neural network binarization, BinaryConnect (BC) and its variants are considered the standard. These methods apply the sign function in their forward pass and their respective gradients are backpropagated to update the weights. However, the derivative of the sign function is zero whenever defined, which consequently freezes training. Therefore, implementations of BC (e.g., BNN) usually replace the derivative of sign in the backward computation with identity or other approximate gradient alternatives. Although such practice works well empirically, it is largely a heuristic or ''training trick.'' We aim at shedding some light on these training tricks from the optimization perspective. Building from existing theory on ProxConnect (PC, a generalization of BC), we (1) equip PC with different forward-backward quantizers and obtain ProxConnect++ (PC++) that includes existing binarization techniques as special cases; (2) derive a principled way to synthesize forward-backward quantizers with automatic theoretical guarantees; (3) illustrate our theory by proposing an enhanced binarization algorithm BNN++; (4) conduct image classification experiments on CNNs and vision transformers, and empirically verify that BNN++ generally achieves competitive results on binarizing these models.Comment: Accepted to NeurIPS 202

Automated home-cage behavioral phenotyping of mice

We describe a trainable computer vision system enabling the automated analysis of complex mouse behaviors. We provide software and a very large manually annotated video database used for training and testing the system. Our system outperforms leading commercial software and performs on par with human scoring, as measured from the ground-truth manual annotations of thousands of clips of freely behaving animals. We show that the home-cage behavior profiles provided by the system is sufficient to accurately predict the strain identity of individual animals in the case of two standard inbred and two non-standard mouse strains. Our software should complement existing sensor-based automated approaches and help develop an adaptable, comprehensive, high-throughput, fine-grained, automated analysis of rodent behavior

SCHEMA Recombination of a Fungal Cellulase Uncovers a Single Mutation That Contributes Markedly to Stability

A quantitative linear model accurately (R^2 = 0.88) describes the thermostabilities of 54 characterized members of a family of fungal cellobiohydrolase class II (CBH II) cellulase chimeras made by SCHEMA recombination of three fungal enzymes, demonstrating that the contributions of SCHEMA sequence blocks to stability are predominantly additive. Thirty-one of 31 predicted thermostable CBH II chimeras have thermal inactivation temperatures higher than the most thermostable parent CBH II, from Humicola insolens, and the model predicts that hundreds more CBH II chimeras share this superior thermostability. Eight of eight thermostable chimeras assayed hydrolyze the solid cellulosic substrate Avicel at temperatures at least 5 °C above the most stable parent, and seven of these showed superior activity in 16-h Avicel hydrolysis assays. The sequence-stability model identified a single block of sequence that adds 8.5 °C to chimera thermostability. Mutating individual residues in this block identified the C313S substitution as responsible for the entire thermostabilizing effect. Introducing this mutation into the two recombination parent CBH IIs not featuring it (Hypocrea jecorina and H. insolens) decreased inactivation, increased maximum Avicel hydrolysis temperature, and improved long time hydrolysis performance. This mutation also stabilized and improved Avicel hydrolysis by Phanerochaete chrysosporium CBH II, which is only 55–56% identical to recombination parent CBH IIs. Furthermore, the C313S mutation increased total H. jecorina CBH II activity secreted by the Saccharomyces cerevisiae expression host more than 10-fold. Our results show that SCHEMA structure-guided recombination enables quantitative prediction of cellulase chimera thermostability and efficient identification of stabilizing mutations

Neural correlates of quantity processing of numeral classifiers.

ObjectiveClassifiers play an important role in describing the quantity information of objects. Few studies have been conducted to investigate the brain organization for quantity processing of classifiers. In the current study, we investigated whether activation of numeral classifiers was specific to the bilateral inferior parietal areas, which are believed to process numerical magnitude.MethodUsing functional MRI, we explored the neural correlates of numeral classifiers, as compared with those of numbers, dot arrays, and nonquantity words (i.e., tool nouns).ResultsOur results showed that numeral classifiers and tool nouns elicited greater activation in the left inferior frontal lobule and left middle temporal gyrus than did numbers and dot arrays, but numbers and dot arrays had greater activation in the middle frontal gyrus, precuneus, and the superior and inferior parietal lobule in the right hemisphere. No differences were found between numeral classifiers and tool nouns.ConclusionThe results suggest that quantity processing of numeral classifiers is independent of that of numbers and dot arrays, supporting the notation-dependent hypothesis of quantity processing

Impact of Brain Injury on Processing of Emotional Prosodies in Neonates

Being able to appropriately process different emotional prosodies is an important cognitive ability normally present at birth. In this study, we used event-related potential (ERP) to assess whether brain injury impacts the ability to process different emotional prosodies (happy, fear, and neutral) in neonates; whether the ERP measure has potential value for the evaluation of neurodevelopmental outcome in later childhood. A total of 42 full-term neonates were recruited from the neonatology department of Peking University First Hospital from June 2014 to January 2015. They were assigned to the brain injury group (n = 20) or control group (n = 22) according to their clinical manifestations, physical examinations, cranial images and routine EEG outcomes. Using an oddball paradigm, ERP data were recorded while subjects listened to happy (20%, deviation stimulus), fearful (20%, deviation stimulus) and neutral (80%, standard stimulus) prosodies to evaluate the potential prognostic value of ERP indexes for neurodevelopment at 30 months of age. Results showed that while the mismatch responses (MMRs) at the frontal lobe were larger for fearful than happy prosody in control neonates, this difference was not observed in neonates with brain injuries. This finding suggests that perinatal brain injury may influence the cognitive ability to process different emotional prosodies in neonatal brain; this deficit could be reflected by decreased MMR amplitudes in response to fearful prosody. Moreover, the decreased MMRs at the frontal lobe was associated with impaired neurodevelopment at 30 months old

Chloroplast genome sequencing of Carya Illinoinensis cv. Xinxuan-4, a new pecan pollinated cultivar

Carya illinoinensis, is a highly valuable nut plant that is cultivated worldwide. As a precious pecan pollination resource, C. illinoinensis cv. Xinxuan-4 is protandrous, with a very early bud break in China. In this study, the chloroplast (cp) genome of 'Xinxuan-4' was sequenced and compared with closely related cultivars. The cp genome was found to be 160,819 bp in length, and it had a common quadripartite architecture with one large single copy (LSC; 90,022 bp), one small single copy (SSC; 18,791 bp), and two inverted repeats (IRs; 26,003 bp). The genome contained 132 genes, including 87 protein-coding genes, 37 tRNA genes, and eight rRNA genes, with a GC content of 36.1%. Furthermore, 278 simple sequence repeats and 59 long repeat sequences were identified, and the genome comparisons revealed that there was a greater divergence in the noncoding regions than in the coding regions. According to the gene selective pressure analysis, five genes (petD, rpl16, rps12, rpoC2, and rpoC1) were identified to be potentially under positive selection when contrasted with the other Carya genotypes. Phylogenetic analysis of the cp genome of 'Xinxuan-4' and 17 other species inferred that Carya is monophyletic and that the genetic relationship between 'Xinxuan-4' and 'Pawnee' is quite close from an evolutionary perspective. The currently characterized cp genome of 'Xinxuan-4' offers useful data for subsequent research on this pecan species

Response of Electric Field in Terrestrial Magnetosphere to Interplanetary Shock

Electric field impulses generated by interplanetary shocks can cause a series of dynamic processes in the Earth's magnetosphere and were previously explained by either fast-mode wave propagation or flow related to compression of the magnetopause. Based on a Space Weather Modeling Framework simulation, we suggest a new scenario in which the evolution of the impulse is due to both the propagation of the fast-mode wave and the compression of the magnetopause, which can explain the simulation and observations in previous related studies. The onset of the electric field impulse is determined by the propagation of the fast-mode wave in the magnetosphere while the peak of the impulse is determined by the propagation of the compression of the magnetopause. The new understanding of the impulse is important for the generation of subsequent ultralow frequency waves through the coupling of the fast-mode to Alfv&eacute;n waves and field line resonances and related radiation-belt electron acceleration. &nbsp;</p

Artemisinic acid attenuates osteoclast formation and titanium particle-induced osteolysis via inhibition of RANKL-induced ROS accumulation and MAPK and NF-κB signaling pathways

Periprosthetic osteolysis (PPO) is the most common cause of joint arthroplasty failure. Its progression involves both biological and mechanical factors. Osteoclastogenesis induced by wear from debris-cell interactions, ultimately leading to excessive bone erosion, is considered the primary cause of PPO; therefore, targeting osteoclasts is a promising treatment approach. Currently available drugs have various side effects and limitations. Artemisinic acid (ArA) is a sesquiterpene isolated from the traditional herb Artemisia annua L. that has various pharmacological effects, such as antimalarial, anti-inflammatory, and antioxidant activities. Therefore, this study was aimed at investigating the effect of ArA on osteoclast formation and bone resorption function in vitro, as well as wear particle-induced osteolysis in vivo, and to explore its molecular mechanism of action. Here, we report that ArA inhibits RANKL-stimulated osteoclast formation and function. Mechanistically, ArA suppresses intracellular reactive oxygen species levels by activating the antioxidant response via nuclear factor erythroid-2-related factor 2 (Nrf2) pathway upregulation. It also inhibits the mitogen-activated kinases (MAPK) and nuclear factor-κB (NF-κB) pathways, as well as the transcription and expression of NFATc1 and c-Fos. In vivo experiments demonstrated that ArA reduces osteoclast formation and alleviates titanium particle-induced calvarial osteolysis. Collectively, our study highlights that ArA, with its osteoprotective and antioxidant effects, is a promising therapeutic agent for preventing and treating PPO and other osteoclast-mediated osteolytic diseases

Low-cost far-field wireless electrical load monitoring system applied in an off-grid rural area of Tanzania

This research article published by Elsevier Ltd., 2020Despite the rapid development of Internet of Things (IoT) technology, there is still a lack of practical wireless energy monitoring methods that can be implemented directly in rural areas with undeveloped infrastructure. To address this gap, this paper presents a novel far-field wireless electrical load monitoring system. By taking advantage of radio frequency (RF) technology, the system realizes one-point-to-multipoint and multichannel communication, thereby extending the effective communication distance of the system and improving its sustainability to the influence of the external environment. The design proposed in this study includes standby equipment to effectively ensure the normal operation of the system in the case of hardware malfunction. The proposed method can be implemented in most geographical regions, neither confined to specific geographic locations nor limited by the level of development of the local infrastructure. Moreover, the hardware of the proposed system is based on Arduino boards, resulting in a low-cost manufacturing process. This system has been applied in a rural area of Tanzania, with 46 households. This paper reports a 238 % increase in power consumption by the residents between the time of initial system deployment, when they had little access to electricity, and the time when accessibility became easy