Global Methodology for Soil Behavior Identification and its Application to the Study of Site Effects

Though it is now admitted that non-linear modeling of soil behavior is necessary to represent some important aspects of the soil response under strong ground motion (for example, irreversible settlements and pore-pressure build-up), the elastoplastic models are not yet used in the everyday design processes. One of the obstacles is the difficulty to identify the models’ parameters. A methodology to identify the soil mechanical parameters is presented and applied to an elastoplastic model. The strategy is based on the use of minimum physical and easily measurable parameters. The key parameter necessary for characterizing the clay is its Liquidity Limit, while for the sand, the grain size distribution plays an important role. Once the methodology presented and validated comparing the response of the model’s response with the available data from the literature, the methodology is used to study the seismic response of the Mexico site

Mitigation of liquefaction seismic risk by preloading

Hazard

Critical Race Theory: An Empirical Investigation of its Benefits

Within the last decade, discussions regarding the implementation of critical race theory in education have gained significant controversy among educators and politicians. Although empirical research on critical race theory is limited, conservative states continue to place bans on the teaching of critical race theory (CRT) in K-12 schools (Carter, 2021). The purpose of this study was to build empirical research on CRT, specifically examining whether a course utilizing a critical race curriculum is effective in reducing negative stereotype beliefs and improving attitudes toward critical race theory. Nineteen undergraduate students who were enrolled in the course, IES 102: The Social Construct of Difference, at Chapman University, were selected to participate in this study. Within the first two weeks of the course, students were recruited to participate in an online pre-test that assessed their beliefs in stereotypes and attitudes toward the concept of critical race theory. In the last four weeks of the course, students were recruited back to complete a similar post-test, assessing their beliefs in stereotypes and attitudes toward the concept of critical race theory again. There was no significant difference between participants’ belief in stereotypes and attitude toward critical race theory before and after exposure to a critical race curriculum. However, students who identify as more liberal had a more positive attitude to CRT, and students who identify within a minority community had fewer beliefs in negative stereotypes. These results are significant as it demonstrates that beliefs in stereotypes and support for a critical race curriculum are dependent on identity. Based on the significant results of this study, educators and advocates should focus on debunking the myths of critical race theory and spreading awareness on its true values and curriculum, especially towards conservative groups. Additionally, educators should utilize activities to build empathy and perspective-taking skills towards “outgroups” to improve intergroup relations

Uma abordagem à modelação de solos não saturados

Os geomateriais das camadas dos pavimentos e das vias-férreas, bem como os das respectivas fundações, encontram- se no estado não saturado nas boas condições de serviço destas infra-estruturas. Torna-se por isso necessário considerar o aspecto não saturado destes materiais na modelação e no dimensionamento destas infra-estruturas. O presente artigo propõe a generalização do conceito de tensão efectiva para solos não saturados. De modo a descrever o comportamento exibido pelos solos não saturados, nomeadamente os fenómenos de colapso durante a humidificação, é proposto um modelo elastoplástico. Este modelo, descrito em termos de tensões efectivas, é calibrado para o caso de uma areia siltosa com base em resultados de ensaios triaxiais clássicos e de precisão com medição da pressão intersticial negativa

Mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-M) and serine biosynthetic pathway genes are co-ordinately increased during anabolic agent-induced skeletal muscle growth

We aimed to identify novel molecular mechanisms for muscle growth during administration of anabolic agents. Growing pigs (Duroc/(Landrace/Large-White)) were administered Ractopamine (a beta-adrenergic agonist; BA; 20ppm in feed) or Reporcin (recombinant growth hormone; GH; 10mg/48hours injected) and compared to a control cohort (feed only; no injections) over a 27-day time course (1, 3, 7, 13 or 27-days). Longissimus Dorsi muscle gene expression was analyzed using Agilent porcine transcriptome microarrays and clusters of genes displaying similar expression profiles were identified using a modified maSigPro clustering algorithm. Anabolic agents increased carcass (p=0.002) and muscle weights (Vastus Lateralis: p<0.001; Semitendinosus: p=0.075). Skeletal muscle mRNA expression of serine/one-carbon/glycine biosynthesis pathway genes (Phgdh, Psat1 and Psph) and the gluconeogenic enzyme, phosphoenolpyruvate carboxykinase-M (Pck2/PEPCK-M), increased during treatment with BA, and to a lesser extent GH (p<0.001, treatment x time interaction). Treatment with BA, but not GH, caused a 2-fold increase in phosphoglycerate dehydrogenase (PHGDH) protein expression at days 3 (p<0.05) and 7 (p<0.01), and a 2-fold increase in PEPCK-M protein expression at day 7 (p<0.01). BA treated pigs exhibit a profound increase in expression of PHGDH and PEPCK-M in skeletal muscle, implicating a role for biosynthetic metabolic pathways in muscle growth

Multimessenger Characterization of Markarian 501 during Historically Low X-Ray and γ-Ray Activity

We study the broadband emission of Mrk 501 using multiwavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi's Large Area Telescope (LAT), NuSTAR, Swift, GASP-WEBT, and the Owens Valley Radio Observatory. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wave bands, with the highest occurring at X-rays and very-high-energy (VHE) 3-rays. A significant correlation (&gt;3σ) between X-rays and VHE 3-rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between the Swift X-Ray Telescope and Fermi-LAT. We additionally find correlations between high-energy 3-rays and radio, with the radio lagging by more than 100 days, placing the 3-ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE 3-rays from mid-2017 to mid-2019 with a stable VHE flux (&gt;0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2 yr long low state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED toward the low state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock. © 2023. The Author(s). Published by the American Astronomical Society

Multi-messenger characterization of Mrk 501 during historically low X-ray and γ\gamma-ray activity

We study the broadband emission of Mrk 501 using multi-wavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi-LAT, NuSTAR, Swift, GASP-WEBT, and OVRO. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wavebands, with the highest occurring at X-rays and very-high-energy (VHE) $\gamma$-rays. A significant correlation ($>$3$\sigma$) between X-rays and VHE $\gamma$-rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between Swift-XRT and Fermi-LAT. We additionally find correlations between high-energy $\gamma$-rays and radio, with the radio lagging by more than 100 days, placing the $\gamma$-ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE $\gamma$-rays from mid-2017 to mid-2019 with a stable VHE flux ($>$0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2-year-long low-state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED towards the low-state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock.Comment: 56 pages, 30 figures, 14 tables, submitted. Corresponding authors are L. Heckmann, D. Paneque, S. Gasparyan, M. Cerruti, and N. Sahakya