419 research outputs found
Solar Power Plant Detection on Multi-Spectral Satellite Imagery using Weakly-Supervised CNN with Feedback Features and m-PCNN Fusion
Most of the traditional convolutional neural networks (CNNs) implements
bottom-up approach (feed-forward) for image classifications. However, many
scientific studies demonstrate that visual perception in primates rely on both
bottom-up and top-down connections. Therefore, in this work, we propose a CNN
network with feedback structure for Solar power plant detection on
middle-resolution satellite images. To express the strength of the top-down
connections, we introduce feedback CNN network (FB-Net) to a baseline CNN model
used for solar power plant classification on multi-spectral satellite data.
Moreover, we introduce a method to improve class activation mapping (CAM) to
our FB-Net, which takes advantage of multi-channel pulse coupled neural network
(m-PCNN) for weakly-supervised localization of the solar power plants from the
features of proposed FB-Net. For the proposed FB-Net CAM with m-PCNN,
experimental results demonstrated promising results on both solar-power plant
image classification and detection task.Comment: 9 pages, 9 figures, 4 table
A Practical Genome Scan for Population-Specific Strong Selective Sweeps That Have Reached Fixation
Phenotypic divergences between modern human populations have developed as a result of genetic adaptation to local environments over the past 100,000 years. To identify genes involved in population-specific phenotypes, it is necessary to detect signatures of recent positive selection in the human genome. Although detection of elongated linkage disequilibrium (LD) has been a powerful tool in the field of evolutionary genetics, current LD-based approaches are not applicable to already fixed loci. Here, we report a method of scanning for population-specific strong selective sweeps that have reached fixation. In this method, genome-wide SNP data is used to analyze differences in the haplotype frequency, nucleotide diversity, and LD between populations, using the ratio of haplotype homozygosity between populations. To estimate the detection power of the statistics used in this study, we performed computer simulations and found that these tests are relatively robust against the density of typed SNPs and demographic parameters if the advantageous allele has reached fixation. Therefore, we could determine the threshold for maintaining high detection power, regardless of SNP density and demographic history. When this method was applied to the HapMap data, it was able to identify the candidates of population-specific strong selective sweeps more efficiently than the outlier approach that depends on the empirical distribution. This study, confirming strong positive selection on genes previously reported to be associated with specific phenotypes, also identifies other candidates that are likely to contribute to phenotypic differences between human populations
Comparison of prognosis between patients of pancreatic head cancer with and without obstructive jaundice at diagnosis
AbstractPurposeThe aim of this study was to elicit possible differences in prognoses and clinicopathological factors in pancreatic head cancer with and without obstructive jaundice at diagnosis.MethodsThe data from 169 patients with pancreatic head cancer were retrospectively analyzed.ResultsPatients were divided into two groups according to serum total bilirubin at diagnosis: ≥3 mg/dL for icteric group and <3 mg/dL for non-icteric group. In all cases, icteric group (n = 104) had a significantly worse prognosis than non-icteric group (n = 65) (median survival time (MST), 7.5 months (M) vs. 13.5 M, respectively; P = 0.049). In 84 resectable cases, icteric group had a significantly worse prognosis than non-icteric group (MST, 14.2 M vs. 20.9 M, respectively; P = 0.049) after almost equivalent treatment intensities. Icteric group had significantly larger T- and N-factors according to the UICC Classification compared to non-icteric group. The total number of lymph node metastases in icteric group was significantly larger than in non-icteric group (P = 0.008). The intrapancreatic nerve invasion in icteric group was significantly stronger than in non-icteric group (P = 0.016). There were no significant differences in the mortality and morbidity between icteric and non-icteric groups. In 85 unresectable cases, there was no significant difference between the survival periods of icteric and non-icteric groups (MST, 5.2 M vs. 5.3 M, respectively).ConclusionsThe presence of obstructive jaundice at diagnosis in patients with pancreatic head cancer may predict an unfavorable survival compared to such patients without obstructive jaundice
Human movement decisions during Coronavirus Disease 2019
To predict epidemics' future course in changing situations, understanding
human mobility patterns is important, notwithstanding decision-making process
uncertainties owing to difficulties in quantifying people's mobility change
decision timings, which make the mobility-epidemic causal relationship unclear.
We used the 'mobility avoidance index' to investigate time-series changes
during Japan's Coronavirus Disease 2019 (eight waves until February 2023) as a
previous study, which measured this index using accommodation reservation
data-booking/cancellation timings-was able to quantify the timing of
decision-making for mobility changes. Our analyses revealed two general
patterns: 1) the index increased/decreased proportional to logarithms of
reported cases during the first wave, conforming with Weber-Fechner's
psychophysics law; 2) its slope against the change in the number of reported
cases had similar values among the waves, but its intercepts changed as the
waves passed, suggesting that people neglected reported cases lower than a
certain threshold for behavioural decision-making. We shifted the threshold
level as the waves passed, and named this pattern 'shift of negligible
epidemic' rule. It is the first pattern quantitatively observed, that possesses
decision making tendencies for future mobility avoidance. Our findings
contribute to constructing a mathematical model, which simultaneously considers
epidemics and human mobility dynamics
Versatile and Enantioselective Preparation of Planar-Chiral Metallocene-Fused 4-Dialkylaminopyridines and Their Application in Asymmetric Organocatalysis
A series of ferrocene-fused planar-chiral N-tosyl-4-pyridones (S)-2b-d were prepared in enantiomerically pure forms. Starting with the chiral ferrocenyl acetals, 1-[(2S,4S)-4-methoxymethyl-1,3-dioxan-2-yl]-1',2',3',4',5'-R5-ferrocenes ((–)-3b, R = Me; (–)-3c, R = Ph; (–)-3d, R = Bn), N-tosylamino and formyl groups were introduced at the 1- and 2-positions of the ferrocene cores in (S)-11b-d with control of the planar chirality. After the reaction with ethynylmagnesium bromide, generated propargyl alcohol derivatives (S)-17 were treated with MnO2 and catalytic TBAI to give the planar-chiral pyridones by the iodide-catalyzed cyclization. This method is highly practical with a shorter and higher-yield sequence without using noble metal catalysts. Planar-chiral ferroco-pyridones (S)-2b-d were reacted with various Me3Si-NR'2 to give a library of ferrocene-fused 4-dialkylaminopyridines ((S)-1, DAAPs) in high yields as single-enantiomers by the detosylative amination. The cymantrene-fused DAAPs were also prepared in the same way. The library of the chiral DAAPs were examined in the two asymmetric reactions as organocatalysts, and some newly prepared Fc-DAAPs showed better enantioselectivity than the known species
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