Earthquake energy dissipation in a fracture mechanics framework.

Earthquakes are rupture-like processes that propagate along tectonic faults and cause seismic waves. The propagation speed and final area of the rupture, which determine an earthquake's potential impact, are directly related to the nature and quantity of the energy dissipation involved in the rupture process. Here, we present the challenges associated with defining and measuring the energy dissipation in laboratory and natural earthquakes across many scales. We discuss the importance and implications of distinguishing between energy dissipation that occurs close to and far behind the rupture tip, and we identify open scientific questions related to a consistent modeling framework for earthquake physics that extends beyond classical Linear Elastic Fracture Mechanics.

Pilot study of the implementation of G8 screening tool, Cognitive screening assessment and Chemotherapy Toxicity assessment in older adults with cancer in a Tertiary University Hospital in Ireland.

BACKGROUND: Comprehensive geriatric assessment (CGA) is recommended by international guidelines prior to initiation of systemic anti-cancer treatment (SACT). In practice, CGA is limited by time constraints, lack of resources and expert interpretation. AIMS: The primary objective of this pilot study was to establish the prevalence of frailty (assessed by G8), cognitive impairment (assessed by Mini-Cog), and risk of chemotherapy toxicity (assessed by CARG Chemo-Toxicity Calculator) among patients (pts) ≥65 years commencing SACT. We selected these three screening tools due to the ease of conducting them in a busy outpatient setting. In addition, they have been validated to predict frailty and risk of toxicity from SACT among older adults with cancer. METHODS: Eligible participants were identified from medical oncology clinics. Assessments were conducted in an outpatient setting by treating physicians. Pt records were reviewed to gather demographic and cancer details. Statistical analyses were conducted using SPSS statistical software. RESULTS: Sixty-three participants were enrolled. The mean age of participants was 73yrs (range=65-88). Thirty-three (52.4%) were female and 30 (47.6%) were male. The majority (n=38, 60.3%) had metastatic cancer. The mean G8 score was 11.9 (range=6-19). Eighty-three percent had a G8 score ≤14. Mini-Cog was positive in 13 pts (21%). The mean CARG score was 7.5 (range=0-16), and 80% had a risk of at least 50% grade ≥3 toxicity. Of these, 48 (76.2%) received chemotherapy and 15 (23.8%) received non-cytotoxic SACT. In multi-variate analyses, age, cancer type, treatment type, and disease stage did not impact G8, Mini-Cog, or CARG scores. CONCLUSIONS: Our study has several limitations but suggests that the majority of older adults with cancer would qualify for formal CGA assessment. The risk of high-grade toxicity from SACT is substantial in this cohort. Chronological age was not found to negatively impact pts' frailty, cognition, or risk of toxicity.

The source scaling and seismic productivity of slow slip transients.

Slow slip events (SSEs) represent a slow faulting process leading to aseismic strain release often accompanied by seismic tremor or earthquake swarms. The larger SSEs last longer and are often associated with intense and energetic tremor activity, suggesting that aseismic slip controls tremor genesis. A similar pattern has been observed for SSEs that trigger earthquake swarms, although no comparative studies exist on the source parameters of SSEs and tremor or earthquake swarms. We analyze the source scaling of SSEs and associated tremor- or swarm-like seismicity through our newly compiled dataset. We find a correlation between the aseismic and seismic moment release indicating that the shallower SSEs produce larger seismic moment release than deeper SSEs. The scaling may arise from the heterogeneous frictional and rheological properties of faults prone to SSEs and is mainly controlled by temperature. Our results indicate that similar physical phenomena govern tremor and earthquake swarms during SSEs.

Linking Circulating Serum Proteins with Clinical Outcomes in Esophageal Adenocarcinoma-An Emerging Role for Chemokines.

Esophageal adenocarcinoma (EAC) is an aggressive cancer with poor prognosis and incidence is increasing rapidly in the Western world. Multi-modal treatment has improved survival outcomes but only for a minority of patients. Currently no markers have been identified to predict treatment response. This study investigated the association between clinical outcomes and pre-treatment levels of 54 serum proteins in n = 80 patients with EAC. Low tumor regression grade (TRG), corresponding to a favorable treatment response, was linked to prolonged overall survival (OS). CCL4 was higher in patients with a favorable treatment response, while Tie2 and CRP were higher in poor responders. Elevated CCL22 and CCL26 was associated with improved OS, while elevated IL-10 showed a negative association. CCL3, CCL4, IL-1α and IL-12/IL23p40 were highest in individuals with no adverse features of tumor biology, whereas levels of Tie2 and VEGF were lowest in this cohort. CCL4 was also elevated in patients with high tumor lymphocyte infiltration. Comparison of matched pre- and post-treatment serum (n = 28) showed a large reduction in VEGFC, and a concomitant increase in other cytokines, including CCL4. These data link several serum markers with clinical outcomes, highlighting an important role for immune cell trafficking in the EAC antitumor immune response.

Novel monitoring techniques for characterizing frictional interfaces in the laboratory.

A pressure-sensitive film was used to characterize the asperity contacts along a polymethyl methacrylate (PMMA) interface in the laboratory. The film has structural health monitoring (SHM) applications for flanges and other precision fittings and train rail condition monitoring. To calibrate the film, simple spherical indentation tests were performed and validated against a finite element model (FEM) to compare normal stress profiles. Experimental measurements of the normal stress profiles were within -7.7% to 6.6% of the numerical calculations between 12 and 50 MPa asperity normal stress. The film also possessed the capability of quantifying surface roughness, an important parameter when examining wear and attrition in SHM applications. A high definition video camera supplied data for photometric analysis (i.e., the measure of visible light) of asperities along the PMMA-PMMA interface in a direct shear configuration, taking advantage of the transparent nature of the sample material. Normal stress over individual asperities, calculated with the pressure-sensitive film, was compared to the light intensity transmitted through the interface. We found that the luminous intensity transmitted through individual asperities linearly increased 0.05643 ± 0.0012 candelas for an increase of 1 MPa in normal stress between normal stresses ranging from 23 to 33 MPa.