Multiobjective genetic algorithm inversion of ground deformation and gravity changes spanning the 1981 eruption of Etna volcano

During the last few decades, joint investigations of microgravity and surface deformation measurements have played an increasingly important role in studying the internal dynamics of active volcanoes. Deformation and microgravity observations have been accomplished at Mt Etna since the eighties. Past data sets collected during important paroxysmal events can be utilized as case-studies to both (1) test the possibilities of nowadays more powerful inversion tools and improved analytical formulations to model the source-mechanisms of volcano-related deformation and gravity changes and (2) in turn obtain new insights into the functioning of the plumbing system of the volcano. Here we analyze a data set spanning the March 1981 eruption of Mt. Etna. Large horizontal displacements were evidenced on the NE and SW flanks of the volcano through electrooptical distance measurements (EDM) during two 20-month periods, both encompassing the March 1981 eruption. Elevation changes, evidenced through leveling measurements, during a 12-month period spanning the eruption, were in general smaller than horizontal displacements with important amplitudes only close to the eruptive fissure. Gravity measurements, carried out together with leveling measurements, evidenced positive changes, spatially well correlated with elevation changes, but having a larger wavelength. The joint inversion of the multimethod geophysical data is regarded as a multiobjective optimization problem and solved through a Genetic Algorithm technique of the nondominated type. We conclude that a composite intrusive mechanism with two tensile cracks, each associated to a zone where preexisting microfractures were filled with new magma, leaded to the 1981 eruption. The results of the present study highlight the advantages of multiobjective evolutionary algorithms, as a powerful tool to jointly invert multimethod geophysical data, and pose important issues on the subject of volcano-monitoring

Histological features of superficial spreading melanoma are associated with and predictive of CDKN2A germline mutations

Dermatology-oncolog

Estimated prevalence, tumor spectrum, and neurofibromatosis type 1-like phenotype of CDKN2A-related melanoma-astrocytoma syndrome

Importance  Knowledge about the prevalence and tumor types of CDKN2A-related melanoma-astrocytoma syndrome (MAS) is limited and could improve disease recognition.Objective  To estimate the prevalence and describe the tumor types of MAS.Design, Setting, and Participants  This retrospective cohort study analyzed all available MAS cases from medical centers in the US (2 sites) and Europe (2 sites) and from biomedical population genomic databases (UK Biobank [United Kingdom], Geisinger MyCode [US]) between January 1, 1976, and December 31, 2020. Patients with MAS with CDKN2A germline pathogenic variants and 1 or more neural tumors were included. Data were analyzed from June 1, 2022, to January 31, 2023.Main Outcomes and Measures  Disease prevalence and tumor frequency.Results  Prevalence of MAS ranged from 1 in 170 503 (n = 1 case; 95% CI, 1:30 098-1:965 887) in Geisinger MyCode (n = 170 503; mean [SD] age, 58.9 [19.1] years; 60.6% women; 96.2% White) to 1 in 39 149 (n = 12 cases; 95% CI, 1:22 396-1:68 434) in UK Biobank (n = 469 789; mean [SD] age, 70.0 [8.0] years; 54.2% women; 94.8% White). Among UK Biobank patients with MAS (n = 12) identified using an unbiased genomic ascertainment approach, brain neoplasms (4 of 12, 33%; 1 glioblastoma, 1 gliosarcoma, 1 astrocytoma, 1 unspecified type) and schwannomas (3 of 12, 25%) were the most common malignant and benign neural tumors, while cutaneous melanoma (2 of 12, 17%) and head and neck squamous cell carcinoma (2 of 12, 17%) were the most common nonneural malignant neoplasms. In a separate case series of 14 patients with MAS from the US and Europe, brain neoplasms (4 of 14, 29%; 2 glioblastomas, 2 unspecified type) and malignant peripheral nerve sheath tumor (2 of 14, 14%) were the most common neural cancers, while cutaneous melanoma (4 of 14, 29%) and sarcomas (2 of 14, 14%; 1 liposarcoma, 1 unspecified type) were the most common nonneural cancers. Cutaneous neurofibromas (7 of 14, 50%) and schwannomas (2 of 14, 14%) were also common. In 1 US family, a father and son with MAS had clinical diagnoses of neurofibromatosis type 1 (NF1). Genetic testing of the son detected a pathogenic CDKN2A splicing variant (c.151-1G>C) and was negative for NF1 genetic alterations. In UK Biobank, 2 in 150 (1.3%) individuals with clinical NF1 diagnoses had likely pathogenic variants in CDKN2A, including 1 individual with no detected variants in the NF1 gene.Conclusions and Relevance  This cohort study estimates the prevalence and describes the tumors of MAS. Additional studies are needed in genetically diverse populations to further define population prevalence and disease phenotypes.Hereditary cancer genetic