Estimation of a coronal mass ejection magnetic field strength using radio observations of gyrosynchrotron radiation

Coronal mass ejections (CMEs) are large eruptions of plasma and magnetic field from the low solar corona into interplanetary space. These eruptions are often associated with the acceleration of energetic electrons which produce various sources of high intensity plasma emission. In relatively rare cases, the energetic electrons may also produce gyrosynchrotron emission from within the CME itself, allowing for a diagnostic of the CME magnetic field strength. Such a magnetic field diagnostic is important for evaluating the total magnetic energy content of the CME, which is ultimately what drives the eruption. Here, we report on an unusually large source of gyrosynchrotron radiation in the form of a type IV radio burst associated with a CME occurring on 2014-September-01, observed using instrumentation from the Nançay Radio Astronomy Facility. A combination of spectral flux density measurements from the Nançay instruments and the Radio Solar Telescope Network (RSTN) from 300 MHz to 5 GHz reveals a gyrosynchrotron spectrum with a peak flux density at ∼1 GHz. Using this radio analysis, a model for gyrosynchrotron radiation, a non-thermal electron density diagnostic using the Fermi Gamma Ray Burst Monitor (GBM) and images of the eruption from the GOES Soft X-ray Imager (SXI), we were able to calculate both the magnetic field strength and the properties of the X-ray and radio emitting energetic electrons within the CME. We find the radio emission is produced by non-thermal electrons of energies >1 MeV with a spectral index of δ ∼ 3 in a CME magnetic field of 4.4 G at a height of 1.3 R�, while the X-ray emission is produced from a similar distribution of electrons but with much lower energies on the order of 10 keV. We conclude by comparing the electron distribution characteristics derived from both X-ray and radio and show how such an analysis can be used to define the plasma and bulk properties of a CME

O impacto da liderança e do contexto organizacional na aceitabilidade ética de práticas de Gestão de Recursos Humanos

Recent research has found that human resource (HR) practitioners judge the acceptability of ethically questionable practices based on the importance their organization attributes to specific features: ethical infrastructure (e.g., codes of conduct) and corporate social responsibility (CSR) practices. The present study sought to evaluate the effects of ethical leadership and the aforementioned features on other non-HR organizational actors. More specifically, this research examined how these individuals judge the acceptability of three ethically dubious HR management (HRM) practices: discrimination, disregard for the individual, and favor shown to those in power. Results obtained for data collected through an online survey indicate that ethical leadership is negatively associated with the acceptability of all three practices. Individuals in organizations with a strong ethical infrastructure also find discrimination and a disregard for the individual less acceptable. The same is true of participants in organizations perceived as more socially responsible regarding employees and economic aspects.info:eu-repo/semantics/publishedVersio

Phyladelphia positive acute lymphoblastic leukemia

O cromossomo Filadélfia (Ph1) é a alteração citogenética mais comum da Leucemia Linfoblástica Aguda do adulto (LLA). Esta alteração citogenética predomina nos adultos com mais de 50 anos e na LLA de origem na célula B, principalmente CD10 positiva. O diagnóstico requer a análise citogenética e a pesquisa do mRNA do gene BCR-ABL no sangue periférico ou na medula óssea. A LLA Ph1 apresenta uma sobrevida global em cinco anos inferior a 20% quando tratada com protocolos para LLA. Os poucos casos de cura ocorrem nos pacientes submetidos ao transplante alogênico de medula óssea (TMO). A adição do imatinibe à quimioterapia resultou em melhora na taxa de remissão completa, maior taxa de remissão molecular completa, maior número de pacientes aptos para realizar o TMO, uma maior sobrevida livre de eventos e maior sobrevida global, embora o tempo de seguimento seja ainda muito curto. Entretanto, a taxa de recaídas e o aparecimento de mutações do BCR-ABL resistentes ao imatinibe ainda são preocupantes. No futuro, novos inibidores de tirosina quinase poderão ser incorporados ao tratamento da LLA Ph1.The Philadelphia chromosome (Ph1) is the most frequent abnormality in acute adult lymphoblastic leukemia (ALL). Ph1 positive ALL is more frequent in over 50-year-old adults, in B-cell ALL and CD10-positive ALL. Diagnosis is based on the identification of the BCR-ABL gene mRNA in peripheral blood or bone marrow. The 5-year overall survival of patients with Ph1 positive ALL treated with chemotherapy alone is less than 20%. A few cases may be cured by allogeneic stem cell transplantation. The addition of imatinib to the chemotherapeutic treatment has resulted in more complete remissions, more complete molecular responses, more patients able to perform stem cell transplantation, better event-free survival and better overall survival, although the study follow-up period is very short so far. High relapse rates and the emergence of BCR-ABL mutants resistant to imatinib are still significant. In the future, newer tyrosine-kinase inhibitors may be added to the chemotherapy

Analysis of intermittency in submillimeter radio and hard x-ray data during the impulsive phase of a solar flare

We present an analysis of intermittent processes occurring during the impulsive phase of the flare SOL2012-03-13, using hard X-rays and submillimeter radio data. Intermittency is a key characteristic in turbulent plasmas and has so far only been analyzed for hard X-ray data. Since in a typical flare the same accelerated electron population is believed to produce both hard X-rays and gyrosynchrotron radiation, we compare the two time profiles by searching for intermittency signatures. For this, we define a cross-wavelet power spectrum, which is used to obtain the local intermittency measure, or LIMLIM. When greater than three, the square LIMLIM coefficients indicate a local intermittent process. The LIM2LIM2 coefficient distribution in time and scale helps to identify avalanche or cascade energy release processes. We find two different and well-separated intermittent behaviors in the submillimeter data: for scales greater than 20 s, a broad distribution during the rising and maximum phases of the emission seems to favor a cascade process; for scales below 1 s, short pulses centered on the peak time are representative of avalanches. When applying the same analysis to hard X-rays, we find that only the scales above 10 s produce a distribution related to a cascade energy fragmentation. Our results suggest that different acceleration mechanisms are responsible for tens of keV and MeV energy ranges of electrons

Transition region and chromospheric signatures of impulsive heating events. II. Modeling

Results from the Solar Maximum Mission showed a close connection between the hard X-ray (HXR) and transition region (TR) emission in solar flares. Analogously, the modern combination of RHESSI and IRIS data can inform the details of heating processes in ways that were never before possible. We study a small event that was observed with RHESSI, IRIS, SDO, and Hinode, allowing us to strongly constrain the heating and hydrodynamical properties of the flare, with detailed observations presented in a previous paper. Long duration redshifts of TR lines observed in this event, as well as many other events, are fundamentally incompatible with chromospheric condensation on a single loop. We combine RHESSI and IRIS data to measure the energy partition among the many magnetic strands that comprise the flare. Using that observationally determined energy partition, we show that a proper multithreaded model can reproduce these redshifts in magnitude, duration, and line intensity, while simultaneously being well constrained by the observed density, temperature, and emission measure. We comment on the implications for both RHESSI and IRIS observations of flares in general, namely that: (1) a single loop model is inconsistent with long duration redshifts, among other observables; (2) the average time between energization of strands is less than 10 s, which implies that for a HXR burst lasting 10 minutes, there were at least 60 strands within a single IRIS pixel located on the flare ribbon; (3) the majority of these strands were explosively heated with an energy distribution well described by a power law of slope »-1.6; (4) the multi-stranded model reproduces the observed line profiles, peak temperatures, differential emission measure distributions, and densities

Chronology of granitic structures in variscan "folded" granite associated to a shear zone (NW PORTUGAL)

Poster apresentado no 32nd International Geological Congress, Florença, Itália, 20-28 Agosto 2004

The relationship between responsible leadership and individual work behaviors: The mediating role of affective commitment

Aims: Recent scandals within the organizational world have bring to light ethical lapses which have discredit organizations, namely in the way they operate in the market, in the type of leaders they have, leading to a strain in the relationship and trust of their stakeholders (Voegtlin et al., 2012; Waldman & Siegel, 2008). With this in mind, a new type of leadership has been called to respond to the challenges organizations are facing - responsible leadership. This leadership type has been related to different consequents (Miska & Mendenhall, 2018), including employees’ attitudes and behaviors at work (Haque et al., 2017; Voegtlin, 2011). Focusing in this relevant stakeholder group, this study aims to further analyze the relationship between responsible leadership and individual behaviors at work (individual performance and organizational citizenship behaviors) and whether employees’ affective commitment to the organization mediates the former relationship. Methodology / Approach: In order to empirically analyze the research model, a quantitative correlational approach was used. The data were collected through an online survey. 298 Portuguese employees from different organizations have answered, voluntarily and anonymously, to the survey. This included previously validated measures selected from the relevant literature (e.g. Voegtlin, 2011) and socio-professional questions. Conclusions / Results: The data were analyzed using PROCESS macro for IBM SPSS 26. The results indicated that there is significant direct relationship between employees’ perceptions of responsible leadership and their individual behaviors. In addition, affective commitment significantly mediates the relationship between responsible leadership and individual work behaviors, both individual performance and organizational citizenship behaviors. Therefore, the findings, suggest that responsible leaders promote employee’s affective bond to the organization, which reinforces individual performance and organizational citizenship behaviors. Research implications: By having responsible leadership, organizations will be able to increase their employee’s affective commitment, and consequently, increase their individual performance and organizational citizenship behaviors. These behaviors are important to improve overall company’s performance and organizational success. Originality: In this investigation, an employee-centered approach to their perspective on responsible leadership and how it influences their affective commitment and their individual work behaviors was used. With this approach, the study has answered to calls for further analysis of responsible leadership’s consequents at the individual level of analysis (Haque et al., 2017; Miska & Mendenhall, 2018).info:eu-repo/semantics/publishedVersio

Ambientes e vida na terra: Os primeiros 4.0 ga

O planeta Terra tem sofrido alterações ao longo do tempo geológico. Pouco tempo decorrido após a sua formação, há cerca de 4.6 Ga, era uma planeta homogéneo. Durante este longo intervalo de tempo, a Geosfera sofreu diversos processos de diferenciação geoquímica e geológica, responsáveis pelo desenvolvimento da actual estrutura interna da Terra. A formação da Atmosfera e da Hidrosfera ocorreu durante o Hadaico, aproximadamente entre 4.5 Ga e 4.4 Ga. A evolução e interacção dos sistemas terrestres, geosfera, atmosfera e hidrosfera, permitiu que fossem reunidas condições favoráveis ao aparecimento da Vida, há pelo menos 3.8 Ga. As formas de Vida foram-se desenvolvendo em diversos ambiente, constituindo outro importante sistema terrestre, a Biosfera. Este artigo tem como principal objectivo a compilação da informação mais relevante relacionada com os principais eventos e outros episódios significantes, que contribuíram para a origem da Vida e seu suporte, tendo como limite temporal o início do Fanerozóico.Environments and Life – the first 4.0 Ga in Earth: The planet Earth has been changing through the geologic time. The Earth was created about 4.6 Ga ago as a homogeneous planet. During this long period of time, several processes occurred originating the geochemical and geological differentiation of the Geosphere and developing the present internal Earth structure. The formation of the Atmosphere and Hydrosphere occurred during the Hadean, approximately 4.5 Ga to 4.4 Ga ago. The evolution and interaction of these important terrestrial systems (geosphere, atmosphere and hydrosphere) allowed, during Earth history, the development of vital conditions for the emergence of Life, at least 3.8 Ga ago. The first organisms might have appeared from the most diverse environments constituting another important system, the Biosphere. The main objective of this article is to compile the most relevant information related with major geological events and other significant episodes, which have contributed to the emergence of Life and its support throughout geological time until Early Paleozoic.Centro de Ciências da Terra (NCT/UM), do Centro de Ciências da Terra (CCT/UM) e do Centro de Geologia da Universidade do Porto (CGUP). Programa de Financiamento Plurianual da FCT, inscrito no POCTI inserido no III Quadro Comunitário de Apoio, co- financiado pelo Governo Português e pela União Europeia (FEDER