Identification of Multiple Hard X-Ray Sources in Solar Flares: A Bayesian Analysis of the 2002 February 20 Event

The hard X-ray emission in a solar flare is typically characterized by a number of discrete sources, each with its own spectral, temporal, and spatial variability. Establishing the relationship among these sources is critical to determining the role of each in the energy release and transport processes that occur within the flare. In this paper we present a novel method to identify and characterize each source of hard X-ray emission. The\uf0a0method permits a quantitative determination of the most likely number of subsources present, and of the relative probabilities that the hard X-ray emission in a given subregion of the flare is represented by a complicated multiple source structure or by a simpler single source. We apply the method to a well-studied flare on 2002 February 20 in order to assess competing claims as to the number of chromospheric footpoint sources present, and hence to the complexity of the underlying magnetic geometry/topology. Contrary to previous claims of the need for multiple sources to account for the chromospheric hard X-ray emission at different locations and times, we find that a simple two-footpoint-plus-coronal-source model is the most probable explanation for the data. We also find that one of the footpoint sources moves quite rapidly throughout the event, a factor that presumably complicated previous analyses. The inferred velocity of the footpoint corresponds to a very high induced electric field, compatible with the fields in thin reconnecting current sheets

Recensioni

Raffaella Leproni, Tra il dire e il fare. L’innovazione educativo-pedagogica dell’opera di Maria Edgeworth, Firenze University Press, Firenze 2015, pp. 215 di Federica FranceschelliG. Alessandrini (a cura di), La “pedagogia” di Martha Nussbaum, approccio allecapacità e sfide educative, Franco Angeli editore, Milano, 2014, pp. 234 di Cristiana SimonettiAlison M. Thompson, The Boy from Hell? Life with a Child with ADHD Paperback,Marzo 13, 2013 di Clarissa SorrentinoOsservare per includere. Metodi di intervento nei contesti socio-educativicon saggi di: Elena Bortolotti, Paolo Sorzio, Federico Mucelli, Sara Bergamo, Corinna Davanzo, Elisabetta Basso, Federica Caruso, Beatrice Belleri, Carocci Editore – Studi Superiori, 2014, pp. 174 di Giusi Zamarr

Exploring the effectiveness of sustainability measurement: which esg metrics will survive covid-19?

This paper aims to investigate the current state of play on Environmental Social and Governance (ESG) integration and check the validity of the current metrics system by assessing if it will survive the COVID-19 crisis. By adopting a qualitative research approach through semi-structured anonymous interviews with 14 senior managers of six European listed companies we use a framework by assessing the mechanisms of reactivity on the effectiveness of ESG measures in times of COVID-19. By interpreting the practitioners’ points of view through the lens of the sociological framework by Espeland and Sauder (Am J Sociol 113:1–40, 2007) our findings show different mechanisms of reactivity by companies on the effectiveness of ESG measures in times of COVID-19, i.e., active and passive conformity and active resistance. We also identified the main Corporate Social Responsibility (CSR) institutional factors that affect managers’ reactivity. An extensive re-formulation of the ESG metrics is required in the light of times of crisis, given that accountability and transparency are strongly linked to quantitative measures which can play a critical role in the financial system and investors’ engagement. Particularly, the strict distinction between “E”, “S” and “G” issues should be abandoned claiming a different holistic re-design of sustainability measures by considering the increasing relevance of the Social dimension in time of COVID-19. This study provides a valuable contribution to the existing literature on the measurement of sustainability within the link of accountability and crisis by highlighting new corporate needs to re-design the ESG metrics system

Psoriasis induced by first‑line pembrolizumab in metastatic non‑small cell lung cancer: a case report

: Therapeutic options for non-small cell lung cancer (NSCLC) have changed with the introduction of immune checkpoint inhibitors. Immunotherapy is generally well tolerated, but can also be associated with severe adverse events, such as the development of new autoimmune diseases. In patients without a history of autoimmune diseases, psoriasis caused by immunotherapy treatment is rarely described in the literature. The present study describes the case of a 68-year-old man with metastatic NSCLC that started chemoimmunotherapy with carboplatin plus pemetrexed plus pembrolizumab. After two cycles of therapy, the patient developed a G3 maculopapular rash. Biopsy confirmed psoriasis and pembrolizumab treatment was discontinued. At the last follow up, the patient was still on maintenance therapy with pemetrexed alone, which is well tolerated. Psoriasis has rarely been reported as an immune-related adverse event. Although the patient had to stop the immunotherapy treatment, the patient is still exhibiting a response to it. Notably, it has previously been described how skin toxicities are associated with a better outcome. Other studies need to be conducted to identify the risk and predictive factors associated with severe immune adverse events and objective response

Contribution of miR-145-5p/Ago2 complex to the regulation of epithelial-mesenchymal transition

The epithelial-mesenchymal transition (EMT) is essential for cell fate determination during development but it is involved in pathological processes like cancer as well, being one of the first steps in the mechanisms leading to metastasis. miR-145-5p is one of the most widely recognized tumor-suppressor miRNAs, able to regulate cell migration and EMT through the contribution of the RISC complex in which Argonaute (Ago) proteins are required for target recognition and gene silencing [1]. Ago2 is an important member of the Ago family and its overexpression correlates with a transformed phenotype in breast cancer cells [2]. With the aim to unravel miR-145-5p/Ago2 contribution to the suppression of cancer progression in epithelial tumors, here we show that: i) miR-145-5p and Ago2 are down-regulated in breast tumor vs normal tissues; ii) the restored expression of miR-145-5p in breast cancer cell lines results in the reduction of tumor phenotype; iii) Ago2 expression is positively and specifically regulated by miR-145-5p; iv) miR-145-5p-dependent Ago2 induction is necessary for the inhibition of cell migration; v) when Ago2 is depleted, the formation of an alternative miR-145-5p/Ago1 active complex redirects miR-145-5p tumor suppressor function and correlates with a more invasive phenotype in breast cancer cells. These results open to the identification of miR-145-5p/Ago2-dependent molecular networks involved in the maintenance and progression of cancer phenotype

The MOCAST+ Study on a Quantum Gradiometry Satellite Mission with Atomic Clocks

In the past twenty years, satellite gravimetry missions have successfully provided data for the determination of the Earth static gravity field (GOCE) and its temporal variations (GRACE and GRACE-FO). In particular, the possibility to study the evolution in time of Earth masses allows us to monitor global parameters underlying climate changes, water resources, flooding, melting of ice masses and the corresponding global sea level rise, all of which are of paramount importance, providing basic data on, e.g. geodynamics, earthquakes, hydrology or ice sheets changes. Recently, a large interest has developed in novel technologies and quantum sensing, which promise higher sensitivity, drift-free measurements, and higher absolute accuracy for both terrestrial surveys and space missions, giving direct access to more precise long-term measurements. Looking at a time frame beyond the present decade, in the MOCAST+ study (MOnitoring mass variations by Cold Atom Sensors and Time measures) a satellite mission based on an “enhanced” quantum payload is proposed, with cold atom interferometers acting as gravity gradiometers, and atomic clocks for optical frequency measurements, providing observations of differences of the gravitational potential. The main outcomes are the definition of the accuracy level to be expected from this payload and the accuracy level needed to detect and monitor phenomena identified in the Scientific Challenges of the ESA Living Planet Program, in particular Cryosphere, Ocean and Solid Earth. In this paper, the proposed payload, mission profile and preliminary platform design are presented, with end-to-end simulation results and assessment of the impact on geophysical applications