Investigating aggregation in ice and snow clouds using novel combination of triple-frequency cloud radars and radar Doppler spectra

Clouds are essential component of the hydrological cycle for transporting of water and distributing precipitation at different parts of the planet. On a global scale, around 63% of the precipitation originates via ice phase. Different ice microphysical processes can lead to growth (e.g. deposition, aggregation, riming) or reduction (e.g. sublimation, breakup) of ice particle sizes. Aggregation, in particular, rapidly increases ice particles sizes and continuously changes the particle size distribution. However, aggregation and other ice microphysical processes are not fully understood. In order to improve the current knowledge about aggregation and the other microphysical processes, microwave radars are used to observe clouds due to their capability of retrieving information through the different parts of the clouds. Additionally, if Doppler radars operating at different frequencies (multi-frequency setup) are used to observe the same region of clouds, the multi-frequency observations can be used to retrieve information of particles sizes and velocities. This thesis uses multi-frequency Doppler observations (6 months) to investigate scenarios that intensify aggregation and the impact of increasing aggregate sizes on raindrop sizes. To this end, a multi-frequency data processing framework is introduced to minimize the effect of attenuation (e.g. atmospheric gases, snow, wet radome) and radar miscalibration; it also assigns a set of quality flags to the different correction steps. The statistical analysis from the observations of the ice part of the clouds indicates that aggregation is intensified in two temperature regions. The first region is between -20 and -10 °C and coincides with the dendritic growth zone (DGZ). Dendritic crystals can favour aggregation due to their branched structure. In addition to the growth of dendrites, the statistical results suggest that an intensification of aggregation in this temperature region correlates with an intensification of updrafts (up to 0.3 m/s). The statistics also show that approximately 25% of the cases where aggregation intensifies an additional mode of small and slow falling particles are present. The temperature region between -10 and 0 °C coincides with the region where the stickiness of ice surfaces increases due to the effect of a quasi liquid layer on the ice surface. Due to this increased stickiness, aggregation intensifies towards the 0 °C isotherm. The statistical results indicate that the growth of large aggregates in the DGZ favour, but it is not sufficient to guarantee the presence of even larger aggregates close to 0 °C. The results also indicate that an increase in aggregate sizes close to the 0 °C correlates with an increase in raindrop sizes. The multi-frequency processing framework and the other filtering processes introduced in this thesis can be used as the foundations for future multi-frequency experiments. The highly qualified multi-frequency dataset and the statistical results from this thesis can be used to evaluate the ice microphysical processes implemented in numerical models

Probing the Effects of Lorentz-Symmetry Violating Chern-Simons and Ricci-Cotton Terms in Higher Derivative Gravity

The combined effects of the Lorentz-symmetry violating Chern-Simons and Ricci-Cotton actions are investigated for the Einstein-Hilbert gravity in the second order formalism modified by higher derivative terms, and their consequences on the spectrum of excitations are analyzed. We follow the lines of previous works and build up an orthonormal basis of operators that splits the fundamental fields according to their individual degrees of freedom. With this new basis, the attainment of the propagators is remarkably simplified and the identification of the physical and unphysical modes gets a new insight. Our conclusion is that the only tachyon- and ghost-free model is the Einstein-Hilbert action added up by the Chern-Simons term with a time-like vector of the type $v^{\mu} = (\mu,\vec{0})$. Spectral consistency imposes taht the Ricci-Cotton term must be switched off. We then infer that gravity with Lorentz-symmetry violation imposes a drastically different constraint on the background if compared to usual gauge theories whenever conditions for suppression of tachyons and ghosts are required.Comment: 15 pages. It coincides with the version published in Phys. Rev.

A procedure for testing the quality of LANDSAT atmospheric correction algorithms

There are two basic methods for testing the quality of an algorithm to minimize atmospheric effects on LANDSAT imagery: (1) test the results a posteriori, using ground truth or control points; (2) use a method based on image data plus estimation of additional ground and/or atmospheric parameters. A procedure based on the second method is described. In order to select the parameters, initially the image contrast is examined for a series of parameter combinations. The contrast improves for better corrections. In addition the correlation coefficient between two subimages, taken at different times, of the same scene is used for parameter's selection. The regions to be correlated should not have changed considerably in time. A few examples using this proposed procedure are presented

Two levels of meaning elaboration in psychological research

Arocha (2021) discusses the “replication crisis,” arguing for models that allow a greater complexity in the relationship between variables and processes. In this comment, we identify a more fundamental issue: the impossibility of eliminating interpretation issues with operational definitions and increased rigor in the measurements of variables and processes. Interpretation is at the core of (a) human action and (b) scientific endeavor. First, considering Vygotsky, we argue that all higher mental processes are sign mediated, influencing psychological research with humans. Second, that the understanding of research results also involves sign mediation and, therefore, it is nonneutral. We suggest two alternative approaches. There needs to be an increase in research that delivers a detailed description of psychological phenomena. Additionally, it is necessary to increase the elucidation of contextual-embeddedness research. Taking into account the two levels of meaning will underline psychology as a scientific discipline of complex phenomena.info:eu-repo/semantics/publishedVersio

Mental health literacy regarding depression and suicide.

Introduction: Mental health literacy enables individuals to recognize the symptoms associated with mental illness, and thus adjust their behavior to manage and seek help and treatment for mental illness. Aims: The present research aims to study determinants of mental health literacy and whether an association exists between mental health literacy and the understanding of content related to depression and suicide. Methods: In each group, the participants read one leaflet about depression or suicide and answered a questionnaire to assess their understanding. All the participants also filled out a mental health literacy self-report. Results: The results showed higher mental health literacy for women and individuals with a higher education. Mental health literacy predicted the understanding of suicide content, but the same did not apply for depression. Conclusions: Mental health literacy stands as an important factor to be considered in developing campaigns and promotional actions. However, its effect remains contingent on the contents and context. It is crucial to consider this interaction in maximizing the campaigns’ impact on the population.info:eu-repo/semantics/publishedVersio

Avanços na compreensão dos padrões evolutivos em Myrtaceae : estudo de caso do complexo de espécies Eugenia involucrata através de uma abordagem integrativa

Myrtaceae inclui espécies vegetais com ampla distribuição mundial, sendo a Oceania e as regiões Neotropicais seus centros de diversidade. Na região Neotropical, a família é mais representada pela tribo Myrteae, com 29 gêneros e 2164 espécies de plantas frutíferas com significativa importância ecológica e econômica. A problemática na sistemática dentro de Myrteae limitou os estudos dentro deste grupo. A tribo inclui grandes gêneros com complexos crípticos de espécies, como Eugenia involucrata DC., uma espécie amplamente difundida e com alta variabilidade morfológica. Assim, a compreensão dos padrões evolutivos de Myrteae é de interesse. O principal objetivo deste estudo é fornecer uma visão geral da evolução das Myrtaceae Neotropicais e desvendar a história evolutiva de um complexo de espécies de Myrteae (Eugenia involucrata) através de uma abordagem integrativa baseada em genética de populações, filogeografia e morfometria. No capítulo II desta tese produzimos um artigo de revisão que contempla estudos de Filogenia, Biogeografia, Genética de Populações, Filogeografia, Citogenética e Genômica de Myrtaceae Neotropicais. A partir da análise desses artigos, evidenciamos avanços significativos na pesquisa e algumas áreas de pesquisa negligenciadas. Também detectamos que algumas espécies apresentam dificuldade de manutenção da diversidade intraespecífica devido a atividades antrópicas. Por um lado, identificamos um aumento no número de estudos filogenéticos baseados em marcadores moleculares nos últimos anos, contribuindo para a compreensão dos padrões macroevolutivos. Por outro lado, encontramos uma carência de estudos abrangendo aspectos microevolutivos, como estudos filogeográficos, os quais foram realizados apenas para duas espécies. No capítulo III, realizamos um estudo de diversidade genética e estrutura populacional de E. involucrata no sul da Floresta Atlântica. Também realizamos uma análise da morfometria geométrica foliar dessa espécie a partir de imagens de exsicatas. As análises populacionais com marcadores moleculares nucleares (ITS) e plastidiais (matK, trnC-ycf6, psbA-trnH, trnS-trnG) revelaram que as populações de E. involucrata no sul da distribuição apresentam uma alta diversidade genética e não estão geneticamente estruturadas. A análise das imagens de exsicatas de E. involucrata mostraram que alguns grupos de plantas apresentaram diferenças no formato das folhas. Em conjunto, esses resultados contribuirão para a compreensão dos processos micro e macroevolutivos na tribo Myrteae, e desvendarão a história evolutiva de E. involucrata. Particularmente para mostrar se a variabilidade fenotípica deste complexo está associada a algum fator ambiental ou genético.Myrtaceae includes plant species with worldwide distribution, with Oceania and Neotropical regions being its centers of diversity. In the Neotropical region, the family is more represented by the Myrteae tribe, with 29 genera and 2164 species of fruit plants with significant ecological and economic importance. The systematic problem within Myrteae limited the studies within this group. The tribe includes large genera with cryptic species complexes, such as Eugenia involucrata DC., a widespread species with high morphological variability. Thus, understanding the evolutionary patterns of Myrteae is of interest. The main objective of this study is to provide an overview of the evolution of Neotropical Myrtaceae and to unravel the evolutionary history of a Myrteae species complex (Eugenia involucrata) through an integrative approach based on population genetics, phylogeography and morphometry. In chapter II of this thesis we produced a review article that includes studies of Phylogeny, Biogeography, Population Genetics, Phylogeography, Cytogenetics and Genomics of Neotropical Myrtaceae. From the analysis of these articles, we evidenced significant advances in research and some neglected research areas. We also detected that some species have difficulties in maintaining intraspecific diversity due to anthropic activities. On the one hand, we have identified an increase in the number of phylogenetic studies based on molecular markers in recent years, contributing to the understanding of macroevolutionary patterns. On the other hand, we found a lack of studies covering microevolutionary aspects, such as phylogeographic studies, which were carried out only for two species. In chapter III, we carried out a study of genetic diversity and population structure of E. involucrata in the southern Atlantic Forest. We also performed an analysis of the leaf morphometry of this species from images of exsiccates. Population analyzes with nuclear (ITS) and plastid (matK, trnC-ycf6, psbA-trnH, trnS-trnG) molecular markers revealed that E. involucrata populations in the southern range have a high genetic diversity and are not genetically structured. The analysis of exsiccates images of E. involucrata, showed that some groups of plants showed differences in leaf shape. Together, these results will contribute to the understanding of micro and macroevolutionary processes in the Myrteae tribe, and will reveal the evolutionary history of E. involucrata. Particularly to show if the phenotypic variability of this complex is associated with some environmental or genetic factor