92 research outputs found
Estrada index of hypergraphs via eigenvalues of tensors
A uniform hypergraph is corresponding to an adjacency tensor
. We define an Estrada index of by using
all the eigenvalues of as
. The bounds for the Estrada indices of uniform
hypergraphs are given. And we characterize the Estrada indices of -uniform
hypergraphs whose spectra of the adjacency tensors are -symmetric.
Specially, we characterize the Estrada indices of uniform hyperstars
In the Storm of COVID-19: College Students’ Perceived Challenges With Virtual Learning
Using open-ended questions, this study surveyed over 450 undergraduate students to gain insights into their perceptions of the virtual learning environment due to the COVID-19 pandemic. Results reveal the rapid transition of most courses to online teaching because of COVID-19 was very challenging for students. A conceptual model was developed on the challenges of virtual learning. The findings reveal three major challenges for virtual learning: learning environment, motivation, and learning effectiveness. Environment and personal characteristics contributed to the lack of motivation to learn. Furthermore, students’ learning behavior and professors’ unpreparedness, and subject matter caused decreased learning effectiveness. The findings of the study can help decision makers at colleges and universities make informed decisions when adopting and/or modifying different teaching/learning environments, as well as professors in developing effective teaching strategies and pedagogy
Sophisticated Deception in Junior Middle School Students: An ERP Study
Sophisticated deception refers to the deception of others based on inferences of their mental states (e.g., answering honestly when inferring that the other will not believe their answer). Studying the brain mechanism of sophisticated deception in junior middle school students can provide physiological evidence for deception detection and deceptive ability measurement. Sixteen junior middle school students were asked to engage in different trial types (i.e., instructed truth/lie and chosen truth/lie), during which we recorded their response times (RT) along with electroencephalographic data to calculate event-related potentials (ERPs). We observed significant differences in amplitude [N2, P3, N450, and medial frontal negativity (MFN)] between chosen reactions (sophisticated deception and simple deception) and instructed reactions (instructed truth and instructed lie) in both the stimulus presentation and feedback stages. In the former, the task scores of participants in the chosen condition were significantly and positively correlated with the N2 amplitude over the central brain area during sophisticated deception. In the latter, the task scores of participants in the chosen condition were negatively correlated with the MFN amplitude over the left frontal and left frontocentral regions. Overall, deception intention, rather than simply making counterfactual statements, appears to underlie the increased demand for cognitive control in deceivers. This can be attributed to deceivers’ need to strongly consider their opponent’s mental state—the better the deceivers’ deceptive ability, the more they will make conjectures about the mental state of their opponent with sophisticated deception and monitor conflict; the less conflict they experience while answering honestly with the intention to deceive, the more conflict may arise when the results of their deception are inconsistent with these conjectures
Case Report: Clinical benefit from multi-target tyrosine kinase inhibitor and PARP inhibitor in a patient with cancer of unknown primary with BRCA1 large genomic rearrangement
Background: Cancer of unknown primary (CUP), which accounts for 3%–5% of new cancer cases every year, involves the presence of a type of histologically confirmed metastatic tumors whose primary site cannot be confirmed by conventional diagnostic methods. This difficulty in identifying the primary site means that CUP patients fail to receive precisely targeted therapy. Most patients are treated with empiric chemotherapy, with a median survival of 6 months and even poorer prognosis within an unfavorable subset of CUP.Case report: An 80-year-old woman presented with masses in the abdomen. Following comprehensive imagological and immunohistochemical examinations, she was diagnosed with CUP. She emphatically declined chemotherapy; thus, anlotinib has been administered with patient consent since 02/07/2019, and stable disease (SD) was observed for 2 years. During subsequent treatment, a large genomic rearrangement in BRCA1 was identified in the patient via NGS, and SD was observed for a further 6 months following olaparib treatment. The type of LGR identified in this patient was discovered to be BRCA1 exon 17-18 inversion (inv), which has never been previously reported.Conclusion: For CUP patients, a chemo-free regimen seems to be acceptable as a first-line treatment, and NGS-guided targeted treatment could improve patient outcomes
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