We propose a lightweight sparsity-based algorithm, namely, the basic thresholding classifier (BTC), for hyperspectral image (HSI) classification. BTC is a pixelwise classifier which uses only the ...spectral features of a given test pixel. It performs the classification using a predetermined dictionary consisting of labeled training pixels. It then produces the class label and residual vector of the test pixel. Since incorporating spatial and spectral information in HSI classification is quite an effective way of improving classification accuracy, we extend our proposal to a three-step spatial-spectral framework. First, every pixel of a given HSI is classified using BTC. The resulting residual vectors form a cube which could be interpreted as a stack of images representing residual maps. Second, each residual map is filtered using an averaging filter. Finally, the class label of each test pixel is determined based on minimal residual. Numerical results on public data sets show that our proposal outperforms well-known support vector machine-based techniques and sparsity-based greedy approaches like simultaneous orthogonal matching pursuit in terms of both classification accuracy and computational cost.
We propose a nonlinear kernel version of recently introduced basic thresholding classifier (BTC) for hyperspectral image (HSI) classification. BTC is a sparsity-based linear classifier, which ...utilizes inner product for similarity measure based on the fact that the hyperspectral data are linearly separable in the feature space. In practice, the pixels of different classes of a given HSI are not always distinct and may overlap. This is known as the inseparability problem, which reduces the performance of a linear classifier. In order to solve this problem in the feature space, we propose the kernel BTC (KBTC) algorithm that achieves promising performance by utilizing well-known "kernel trick." To increase the classification accuracy further, we present spatial-spectral KBTC that incorporates spatial information using weighted least squares filter with a guidance image. Furthermore, we apply L 0 smoothing technique on the guidance image, which provides additional improvements. Experimental results on publicly available HSI data sets showed that the proposal and its spatial extension yield better classification results as compared with linear similarity-based BTC, nonlinear kernel-based support vector machines, kernel orthogonal matching pursuit, recently proposed logistic regression via splitting and augmented Lagrangian, and their spatial extensions.
The immune checkpoint PD-1 and its receptor B7-H1 (PD-L1) are successful therapeutic targets in cancer but less is known about other B7 family members. Here, we determined the expression level of ...B7-H3 protein in non-small cell lung cancer (NSCLC) and evaluated its association with tumor-infiltrating lymphocytes (TIL), PD-L1, B7-H4, and major clinicopathologic characteristics is in 3 NSCLC cohorts.
We used multiplexed automated quantitative immunofluorescence (QIF) to assess the levels of B7-H3, PD-L1, B7-H4, and TILs in 634 NSCLC cases with validated antibodies. Associations between the marker levels, major clinicopathologic variables and survival were analyzed.
Expression of B7-H3 protein was found in 80.4% (510/634) of the cases. High B7-H3 protein level (top 10 percentile) was associated with poor overall survival (
< 0.05). Elevated B7-H3 was consistently associated with smoking history across the 3 cohorts, but not with sex, age, clinical stage, and histology. Coexpression of B7-H3 and PD-L1 was found in 17.6% of the cases (112/634) and with B7-H4 in 10% (63/634). B7-H4 and PD-L1 were simultaneously detected only in 1.8% of NSCLCs (12/634). The expression of B7-H3 was not associated with the levels of CD3-, CD8-, and CD20-positive TILs.
B7-H3 protein is expressed in the majority of NSCLCs and is associated with smoking history. High levels of B7-H3 protein have a negative prognostic impact in lung carcinomas. Coexpression of B7-H3 with PD-L1 and B7-H4 is relatively low, suggesting a nonredundant biological role of these targets.
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Although most activating mutations of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancers (NSCLCs) are sensitive to available EGFR tyrosine kinase inhibitors (TKIs), a subset ...with alterations in exon 20 of EGFR and HER2 are intrinsically resistant and lack an effective therapy. We used in silico, in vitro, and in vivo testing to model structural alterations induced by exon 20 mutations and to identify effective inhibitors. 3D modeling indicated alterations restricted the size of the drug-binding pocket, limiting the binding of large, rigid inhibitors. We found that poziotinib, owing to its small size and flexibility, can circumvent these steric changes and is a potent inhibitor of the most common EGFR and HER2 exon 20 mutants. Poziotinib demonstrated greater activity than approved EGFR TKIs in vitro and in patient-derived xenograft models of EGFR or HER2 exon 20 mutant NSCLC and in genetically engineered mouse models of NSCLC. In a phase 2 trial, the first 11 patients with NSCLC with EGFR exon 20 mutations receiving poziotinib had a confirmed objective response rate of 64%. These data identify poziotinib as a potent, clinically active inhibitor of EGFR and HER2 exon 20 mutations and illuminate the molecular features of TKIs that may circumvent steric changes induced by these mutations.
STK11 and KEAP1 mutations (STK11 mutant STK11MUT and KEAP1MUT) are among the most often mutated genes in lung adenocarcinoma (LUAD). Although STK11MUT has been associated with resistance to ...programmed death-(ligand)1 (PD-L1) inhibition in KRASMUT LUAD, its impact on immunotherapy efficacy in KRAS wild-type (KRASWT) LUAD is currently unknown. Whether KEAP1MUT differentially affects outcomes to PD-(L)1 inhibition in KRASMUT and KRASWT LUAD is also unknown.
Clinicopathologic and genomic data were collected from September 2013 to September 2020 from patients with advanced LUAD at the Dana-Farber Cancer Institute/Massachusetts General Hospital cohort and the Memorial Sloan Kettering Cancer Center/MD Anderson Cancer Center cohort. Clinical outcomes to PD-(L)1 inhibition were analyzed according to KRAS, STK11, and KEAP1 mutation status in two independent cohorts. The Cancer Genome Atlas transcriptomic data were interrogated to identify differences in tumor gene expression and tumor immune cell subsets, respectively, according to KRAS/STK11 and KRAS/KEAP1 comutation status.
In the combined cohort (Dana-Farber Cancer Institute/Massachusetts General Hospital + Memorial Sloan Kettering Cancer Center/MD Anderson Cancer Center) of 1261 patients (median age = 61 y range: 22–92, 708 women 56.1%, 1065 smokers 84.4%), KRAS mutations were detected in 536 cases (42.5%), and deleterious STK11 and KEAP1 mutations were found in 20.6% (260 of 1261) and 19.2% (231 of 1202) of assessable cases, respectively. In each independent cohort and in the combined cohort, STK11 and KEAP1 mutations were associated with significantly worse progression-free (STK11 hazard ratio HR = 2.04, p < 0.0001; KEAP1 HR = 2.05, p < 0.0001) and overall (STK11 HR = 2.09, p < 0.0001; KEAP1 HR = 2.24, p < 0.0001) survival to immunotherapy uniquely among KRASMUT but not KRASWT LUADs. Gene expression ontology and immune cell enrichment analyses revealed that the presence of STK11 or KEAP1 mutations results in distinct immunophenotypes in KRASMUT, but not in KRASWT, lung cancers.
STK11 and KEAP1 mutations confer worse outcomes to immunotherapy among patients with KRASMUT but not among KRASWT LUAD. Tumors harboring concurrent KRAS/STK11 and KRAS/KEAP1 mutations display distinct immune profiles in terms of gene expression and immune cell infiltration.
Araştırma, elektriğin iletimi ünitesinde fen bilimleri öğretmenlerinin bağlam önerilerini tespit etmek amacıyla yapılmıştır. Tarama çalışması olarak yürütülen bu araştırmanın çalışma grubunu, ...Türkiye’nin 7 coğrafi bölgesinde görev yapan 178 fen bilimleri öğretmeni oluşturmaktadır. Araştırmanın verileri 6.sınıf fen bilimleri dersi öğretim programındaki ilgili üniteye ait her bir kazanım için hazırlanan açık uçlu sorular ile toplanmıştır. Veriler içerik analizine tabi tutulmuştur. Elde edilen bulgulara göre öğretmenler 6.sınıf elektrik konusunda en çok “iletken ve yalıtkan maddeler, elektriğin taşınmasında iletkenlerin kullanımı, değişken direnç, benzeşim (analoji), enerji dönüşümü” içeriklerini bağlam olarak önermektedir. Bunun yanı sıra fen bilimleri öğretmenlerinin öğretim programına uygun olmayan (kazanımla ilişkisiz) bağlam önerdikleri ve kazanımları bağlamlaştırmada zorlandıkları tespit edilmiştir. Elektriğin iletimi ünitesi için ülke geneline yönelik öğretim materyali tasarlayacak ilgili paydaşların, bulgulardan hareketle, fen bilimleri öğretmenleri tarafından sunulan bağlam örneklerini dikkate almaları önerilmektedir.
The research was carried out to determine the context suggestions of science teachers about the transmission of electricity unit. The study group of this research, which was conducted as a survey study, consists of 178 science teachers working in 7 geographical regions of Turkey. The data of the research were collected with open-ended questions prepared for each objectives of the related unit in the 6th grade science curriculum. The data were subjected to content analysis. According to the findings, the teachers mostly preferred “conductors and insulators, the use of “Conductors in conveying electricity, variable resistor; analogy, energy transformation” as a context. In addition, it has been determined that science teachers suggest contexts that are not suitable for the curriculum (unrelated to the objectives) and have difficulty in contextualizing the objectives. It is suggested that relevant stakeholders who will design instructional materials for the nationwide unit for the transmission of electricity should consider the context examples suggested by science teachers, based on the findings.
The aim of this study is to develop a concept test on the subject of stars that is suitable for model analysis and to evaluate the conformity of this model. The study was performed using a screening ...model, which is a type of quantitative research method. The study also tried to fill the gap in the existing literature regarding the use of quantitative methods. To develop the test, existing studies on stars were first examined; interviews with candidates who were teachers were conducted; and finally, necessary amendments to test items were made after referring to experts' opinions. To assure its validity and reliability, the test was applied to a total of 175 candidates who were studying at schools of education in the departments of science teaching of three different universities to become teachers; all candidates took astronomy courses and were educated on the subject matter. The final form of the test was comprised of 26 multiple-choice questions, each with 5 possible answers. The Cronbach's alpha reliability coefficient of the test was calculated to be 0.735. In addition, the mean strength of the test was found to be 0.370 and the distinctiveness was found to be 0.390. Statistical analyses revealed that the concept test developed in this study is a valid and reliable test that conforms to the model analysis.
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