Publications by authors named "I M Reid"

1,197 Publications

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Effective Training of Convolutional Neural Networks with Low-bitwidth Weights and Activations.

IEEE Trans Pattern Anal Mach Intell 2021 Jun 14;PP. Epub 2021 Jun 14.

This paper tackles the problem of training a deep convolutional neural network of both low-bitwidth weights and activations. Optimizing a low-precision network is challenging due to the non-differentiability of the quantizer, which may result in substantial accuracy loss. To address this, we propose three practical approaches, including (i) progressive quantization; (ii) stochastic precision; and (iii) joint knowledge distillation to improve the network training. First, for progressive quantization, we propose two schemes to progressively find good local minima. Specifically, we propose to first optimize a net with quantized weights and subsequently quantize activations. This is in contrast to the traditional methods which optimize them simultaneously. Furthermore, we propose a second scheme which gradually decreases the bit-width from high-precision to low-precision during training. Second, to alleviate the excessive training burden due to the multi-round training stages, we further propose a one-stage stochastic precision strategy to randomly sample and quantize sub-networks while keeping other parts in full-precision. Finally, we propose to jointly train a full-precision model alongside the low-precision one. By doing so, the full-precision model provides hints to guide the low-precision model training and significantly improves the performance of the low-precision network. Extensive experiments show the effectiveness of the proposed methods.
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http://dx.doi.org/10.1109/TPAMI.2021.3088904DOI Listing
June 2021

Genetic Characterization of Mutations Related to Conidiophore Stalk Length Development in Laboratory Strain N402.

Front Genet 2021 20;12:666684. Epub 2021 Apr 20.

Institute of Biology Leiden, Microbial Sciences, Leiden University, Leiden, Netherlands.

is an important filamentous fungus in industrial biotechnology for the production of citric acid and enzymes. In the late 1980s, the N400/NRRL3 strain was selected for both fundamental and applied studies in relation to several processes including gluconic acid and protein production. To facilitate handling of , the N400 wild-type strain was UV mutagenized in two consecutive rounds to generate N401 and N402. N402 was used as a reference laboratory strain and exhibits the phenotypes with reduced conidiophore stalk length and reduced radial growth. The conidiophore stalk length and radial growth of strain N400 were determined and compared to N401 and N402. The length of N400 conidiophore stalks (2.52 ± 0.40 mm) was reduced in N401 and N402 to 0.66 ± 0.14 mm and 0.34 ± 0.06 mm, respectively. Whereas N400 reached a colony diameter of 6.7 ± 0.2 cm after 7 days, N401 and N402 displayed reduced radial growth phenotype (4.3 ± 0.1 and 4.1 ± 0.1, respectively). To identify the mutations (dubbed and ) responsible for the phenotypes of N401 and N402, the genomes were sequenced and compared to the N400 genome sequence. A parasexual cross was performed between N400 and N402 derivatives to isolate segregants which allowed cosegregation analysis of single nucleotide polymorphisms and insertions and deletions among the segregants. The shorter conidiophore stalk and reduced radial growth in N401 () was found to be caused by a 9-kb deletion on chromosome III and was further narrowed down to a truncation of NRRL3_03857 which encodes a kinesin-like protein homologous to the UncA protein. The mutation responsible for the further shortening of conidiophore stalks in N402 () was found to be caused by a missense mutation on chromosome V in a hitherto unstudied C2H2 transcription factor encoded by the gene NRRL3_06646. The importance of these two genes in relation to conidiophore stalk length and radial growth was confirmed by single and double gene deletion studies. The mutations in the laboratory strain N402 should be taken into consideration when studying phenotypes in the N402 background.
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http://dx.doi.org/10.3389/fgene.2021.666684DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8093798PMC
April 2021

Measurements of production cross sections and constraints on anomalous triple gauge couplings at .

Eur Phys J C Part Fields 2021 1;81(3):200. Epub 2021 Mar 1.

Universiteit Antwerpen, Antwerpen, Belgium.

The production of Z boson pairs in proton-proton ( ) collisions, , where or , is studied at a center-of-mass energy of 13 with the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 137 , collected during 2016-2018. The production cross section, , measured for events with two pairs of opposite-sign, same-flavor leptons produced in the mass region is consistent with standard model predictions. Differential cross sections are also measured and agree with theoretical predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous and couplings.
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http://dx.doi.org/10.1140/epjc/s10052-020-08817-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7921081PMC
March 2021

Loss of function of the carbon catabolite repressor CreA leads to low but inducer-independent expression from the feruloyl esterase B promoter in Aspergillus niger.

Biotechnol Lett 2021 Jul 18;43(7):1323-1336. Epub 2021 Mar 18.

Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.

Objective: With the aim to decipher the mechanisms involved in the transcriptional regulation of feruloyl esterase encoded by faeB, a genetic screen was performed to isolate A. niger mutants displaying inducer-independent expression from the faeB promoter.

Result: PfaeB-amdS and PfaeB-lux dual reporter strains were constructed and used to isolate trans-acting mutants in which the expression of both reporters was increased, based on the ability to grow on acetamide plates and higher luciferase activity, respectively. The genetic screen on the non-inducing carbon source D-fructose yielded in total 111 trans-acting mutants. The genome of one of the mutants was sequenced and revealed several SNPs, including a point mutation in the creA gene encoding a transcription factor known to be involved in carbon catabolite repression. Subsequently, all mutants were analyzed for defects in carbon catabolite repression by determining sensitivity towards allyl alcohol. All except four of the 111 mutants were sensitive to allyl alcohol, indicating that the vast majority of the mutants are defective in carbon catabolite repression. The creA gene of 32 allyl alcohol sensitive mutants was sequenced and 27 of them indeed contained a mutation in the creA gene. Targeted deletion of creA in the reporter strain confirmed that the loss of CreA results in constitutive expression from the faeB promoter.

Conclusion: Loss of function of CreA leads to low but inducer-independent expression from the faeB promoter in A. niger.
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http://dx.doi.org/10.1007/s10529-021-03104-2DOI Listing
July 2021