Maus tratos na infância, funções executivas, eventos estressores e desempenho escolar em adolescentes

The presence of childhood maltreatment is related to worse cognitive functioning in adolescents. In addition, stressful events experienced during adolescence are also factors that influence negatively, cognitive functioning and academic performance. In order to investigate the association between maltreatment suffered in childhood, stressful events experienced during adolescence, executive functioning and school performance of teenagers, this dissertation had a correlational and cross-sectional design and consists of two empirical studies, presented in the form of articles. In both studies, participants were teenagers, students from seven public schools in Porto Alegre, aged between 12 and 18 years, identified from data collection performed by one of the projects developed by the Post Doctoral in Psychology Program at PUCRS. This program aims to investigate the effects of exposure to maltreatment on cognition and the expression of psychopathology in adolescence, adulthood and old age. The sample of this study included 83 adolescents who were divided into two groups: presence of childhood maltreatment (case group) and absence of childhood maltreatment (Control Group). Participants were assessed individually at their schools. For data collection, the following instruments were applied: Arithmetic Subtest digits of the WISC-III or WAIS-III, TMT, Hayling Test and verbal fluency (FAS), and Vocabulary subtests of the WISC-III or WAIS-III, Events Inventory Stressors in Adolescence, Childhood Trauma Questionnaire (CTQ), Data Sheet Sociodemographic and Economic Classification Criterion Brazil. In the first study, the group was divided into two subgroups: participants who had the presence of only a single type of child maltreatment (sexual abuse, emotional, physical, emotional or physical neglect), and those who had the presence of multiple types of childhood maltreatment. In the second study, the groups were divided between students who have had a grade repetition at school, and those who had not. For the evaluation of academic performance, we used the grades of Portuguese, Mathematics, History and Geography of the previous year's report card. It was found that adolescents who experienced childhood maltreatment had worse performance in executive functions. Students who have repeated the school year had experienced more stressful events during adolescence, had poorer grades and worse executive performance, when compared to those who did not repeat the school year. In addition, the students who have grade repetition had experienced more stressful events in adolescence, had lower grades and had worse executive functioning, when compared to those who did not repeat a school year. Overall, these results point to a relationship between the experiences of childhood maltreatment and stressful events during adolescence and a poor executive functioning and academic performance related to.A presença de maus tratos na infância está relacionada ao pior funcionamento cognitivo em adolescentes. Além disso, os eventos estressores vivenciados na adolescência são fatores que também influenciam, de forma prejudicial, o funcionamento cognitivo e o desempenho acadêmico. A fim que investigar se existe associação entre maus tratos sofridos na infância, eventos estressores experienciados na adolescência, funcionamento executivo e desempenho escolar de adolescentes, esta dissertação teve um delineamento transversal correlacional e é composta por dois estudos empíricos, apresentados na forma de artigos. Em ambos os estudos, os participantes foram adolescentes, estudantes de sete escolas públicas de Porto Alegre, com idades entre 12 e 18 anos, identificados a partir da coleta de dados realizada por um dos projetos do Programa Nacional de Pós Doutorado em Psicologia da PUCRS. Este programa tem por objetivo investigar os efeitos da exposição a maus tratos sobre a cognição e a expressão de psicopatologia na adolescência, na adultez e na velhice. Dentre os 613 adolescentes que participaram da pesquisa do PNPD, a amostra do presente estudo englobou 83 alunos que foram divididos em dois grupos: presença de maus tratos na infância (Grupo Caso) e ausência de maus tratos na infância (Grupo Controle). Os participantes foram avaliados, individualmente, em suas escolas. Para coleta dos dados, foram aplicados o Subteste Aritmética e dígitos da WISC-III ou do WAIS-III, TMT, Teste Hayling e tarefa de fluência verbal (FAS), subtestes Cubos e Vocabulário da WISC-III ou do WAIS-III, Inventário de Eventos Estressores na Adolescência, Childhood Trauma Questionnaire (CTQ), Ficha de Dados Sociodemográficos e Critério de Classificação Econômica Brasil. No primeiro estudo, o grupo caso foi divido em dois subgrupos, participantes que tiveram a presença de apenas um único tipo de maus tratos na infância (abuso sexual, emocional, físico, negligência física ou emocional), e os que tiveram a presença de múltiplos tipos de maus tratos na infância. Já no segundo estudo, os grupos foram divididos entre os alunos que tiveram uma repetição de ano na escola e os que não tiveram. Para a avaliação do desempenho acadêmico, foram utilizadas as notas das matérias de Português, Matemática, História e Geografia do boletim escolar do ano anterior. Verificou-se que os adolescentes que sofreram maus tratos na infância obtiveram pior desempenho nos componentes de flexibilidade cognitiva, velocidade de processamento visual, capacidade de iniciação e velocidade de processamento verbal. Além disso, os alunos que repetiram de ano vivenciaram mais eventos estressores na adolescência, tiraram piores notas e tiveram um piorfuncionamento executivo, quando comparados com os que não repetiram de ano. De forma geral, esses resultados apontam para a relação entre a vivência de maus tratos na infância e de eventos estressores na adolescência e um pior funcionamento executivo e desempenho escolar

Estimating volcanic deformation source parameters with a Finite Element inversion: the 2001-2002 unrest at Cotopaxi volcano, Ecuador

This is the final version of the article. Available from the publisher via the DOI in this record.Deformation at Cotopaxi was observed between 2001 and 2002 along with recorded seismicity beneath the northeast (NE) flank, despite the fact that the last eruption occurred in 1942. We use electronic distance meter deformation data along with the patterns of recorded seismicity to constrain the cause of this unrest episode. To solve for the optimum deformation source parameters we employ inverse finite element (FE) models that account for material heterogeneities and surface topography. For a range of source shapes the models converge on a shallow reservoir beneath the southwest (SW) flank. The individual best fit model is a small oblate-shaped source, approximately 4–5 km beneath the summit, with a volume increase of roughly 20 × 106 m3. This SW source location contrasts with the NE seismicity locations. Subsequently, further FE models that additionally account for temperature-dependent viscoelasticity are used to reconcile the deformation and seismicity simultaneously. Comparisons of elastic and viscous timescales allude to aseismic pressurization of a small magma reservoir in the SW. Seismicity in the NE is then explained through a mechanism of fluid migration from the SW to the NE along fault systems. We extend our analyses to further show that if future unrest crises are accompanied by measurable seismicity around the deformation source, this could indicate a higher magma supply rate and increased likelihood of a forthcoming eruption.The data informing this paper is available upon request to the lead author. This work was supported by the European Commission, Framework Program 7 (grant 282759, VUELCO, and grant 308665, MEDSUV), the Natural Environmental Research Council (NE/G01843X/1), and the Royal Society (UF090006). We thank reviewers A. Gudmundsson and L. Crescentini, and Editor A. Revil, for their comments which helped to improve the paper. We also thank Mark Jellinek for thoughtful discussions during manuscript preparation

Lava flow morphology at an erupting andesitic stratovolcano: a satellite perspective on El Reventador, Ecuador

Lava flows pose a significant hazard to infrastructure and property located close to volcanoes, and understanding how flows advance is necessary to manage volcanic hazard during eruptions. Compared to low-silica basaltic flows, flows of andesite composition are infrequently erupted and so relatively few studies of their characteristics and behaviour exist. We use El Reventador, Ecuador as a target to investigate andesitic lava flow properties during a 4.5 year period of extrusive eruption between February 2012 and August 2016. We use satellite radar to map the dimensions of 43 lava flows and look at variations in their emplacement behaviour over time. We find that flows descend the north and south flanks of El Reventador, and were mostly emplaced during durations shorter than the satellite repeat interval of 24 days.Flows ranged in length from 0.3 to 1.7 km, and the length of these flows decreased over the observation period. We measure a decrease in flow volume with time that is correlated with a long-term exponential decrease in eruption rate, and propose that this behaviour is caused by temporary magma storage in the conduit acting as a melt capacitor between the magma reservoir and the surface. We use the dimensions of the flow levees and widths to estimate the flow yield strengths, which were of the order of 10-100 kPa. We observe that some flows were diverted by topographic obstacles, and compare measurements of decreased channel width and increased flow thickness at the obstacles with observations from laboratory experiments. Radar observations, such as those presented here, could be used to map and measure properties of evolving lava flow fields at other remote or difficult to monitor volcanoes

Low-Density Granulocytes Are a Novel Immunopathological Feature in Both Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder

Objective: To investigate whether low-density granulocytes (LDGs) are an immunophenotypic feature of patients with multiple sclerosis (MS) or neuromyelitis optica spectrum disorder (NMOSD). Methods: Blood samples were collected from 20 patients with NMOSD and 17 patients with MS, as well as from 15 patients with Systemic Lupus Erythematosus (SLE) and 23 Healthy Donors (HD). We isolated peripheral blood mononuclear cells (PBMCs) with density gradient separation and stained the cells with antibodies against CD14, CD15, CD16, and CD45, and analyzed the cells by flow cytometry or imaging flow cytometry. We defined LDGs as CD14-CD15(high) and calculated their share in total PBMC leukocytes (CD45+) as well as the share of CD16(hi) LDGs. Clinical data on disease course, medication, and antibody status were obtained. Results: LDGs were significantly more common in MS and NMOSD than in HDs, comparable to SLE samples (median values HD 0.2%, MS 0.9%, NMOSD 2.1%, SLE 4.3%). 0/23 of the HDs, but 17/20 NMOSD and 11/17 MS samples as well as 13/15 SLE samples had at least 0.7 % LDGs. NMOSD patients without continuous immunosuppressive treatment had significantly more LDGs compared to their treated counterparts. LDG nuclear morphology ranged from segmented to rounded, suggesting a heterogeneity within the group. Conclusion: LDGs are a feature of the immunophenotype in some patients with MS and NMOSD

Analyzing nicotinamide adenine dinucleotide phosphate oxidase activation in aging and vascular amyloid pathology

In aging individuals, both protective as well as regulatory immune functions are declining, resulting in an increased susceptibility to infections as well as to autoimmunity. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2-deficiency in immune cell subsets has been shown to be associated with aging. Using intravital marker-free NAD(P)H-fluorescence lifetime imaging, we have previously identified microglia/myeloid cells and astrocytes as main cellular sources of NADPH oxidase (NOX) activity in the CNS during neuroinflammation, due to an overactivation of NOX. The overactivated NOX enzymes catalyze the massive production of the highly reactive O−2, which initiates in a chain reaction the overproduction of diverse reactive oxygen species (ROS). Age-dependent oxidative distress levels in the brain and their cellular sources are not known. Furthermore, it is unclear whether in age- dependent diseases oxidative distress is initiated by overproduction of ROS or by a decrease in antioxidant capacity, subsequently leading to neurodegeneration in the CNS. Here, we compare the activation level of NOX enzymes in the cerebral cortex of young and aged mice as well as in a model of vascular amyloid pathology. Despite the fact that a striking change in the morphology of microglia can be detected between young and aged individuals, we find comparable low-level NOX activation both in young and old mice. In contrast, aged mice with the human APPE693Q mutation, a model for cerebral amyloid angiopathy (CAA), displayed increased focal NOX overactivation in the brain cortex, especially in tissue areas around the vessels. Despite activated morphology in microglia, NOX overactivation was detected only in a small fraction of these cells, in contrast to other pathologies with overt inflammation as experimental autoimmune encephalomyelitis (EAE) or glioblastoma. Similar to these pathologies, the astrocytes majorly contribute to the NOX overactivation in the brain cortex during CAA. Together, these findings emphasize the role of other cellular sources of activated NOX than phagocytes not only during EAE but also in models of amyloid pathology. Moreover, they may strengthen the hypothesis that microglia/monocytes show a diminished potential for clearance of amyloid beta protein

Volcanic eruption forecasts from accelerating rates of drumbeat long-period earthquakes

Abstract Accelerating rates of quasiperiodic “drumbeat” long‐period earthquakes (LPs) are commonly reported before eruptions at andesite and dacite volcanoes, and promise insights into the nature of fundamental preeruptive processes and improved eruption forecasts. Here we apply a new Bayesian Markov chain Monte Carlo gamma point process methodology to investigate an exceptionally well‐developed sequence of drumbeat LPs preceding a recent large vulcanian explosion at Tungurahua volcano, Ecuador. For more than 24 hr, LP rates increased according to the inverse power law trend predicted by material failure theory, and with a retrospectively forecast failure time that agrees with the eruption onset within error. LPs resulted from repeated activation of a single characteristic source driven by accelerating loading, rather than a distributed failure process, showing that similar precursory trends can emerge from quite different underlying physics. Nevertheless, such sequences have clear potential for improving forecasts of eruptions at Tungurahua and analogous volcanoes

Aquatic community response to volcanic eruptions on the Ecuadorian Andean flank: evidence from the palaeoecological record

Aquatic ecosystems in the tropical Andes are under increasing pressure from human modification of the landscape (deforestation and dams) and climatic change (increase of extreme events and 1.5 °C on average temperatures are projected for AD 2100). However, the resilience of these ecosystems to perturbations is poorly understood. Here we use a multi-proxy palaeoecological approach to assess the response of aquatic ecosystems to a major mechanism for natural disturbance, volcanic ash deposition. Specifically, we present data from two Neotropical lakes located on the eastern Andean flank of Ecuador. Laguna Pindo (1°27.132′S–78°04.847′W) is a tectonically formed closed basin surrounded by a dense mid-elevation forest, whereas Laguna Baños (0°19.328′S–78°09.175′W) is a glacially formed lake with an inflow and outflow in high Andean Páramo grasslands. In each lake we examined the dynamics of chironomids and other aquatic and semi-aquatic organisms to explore the effect of thick (> 5 cm) volcanic deposits on the aquatic communities in these two systems with different catchment features. In both lakes past volcanic ash deposition was evident from four large tephras dated to c.850 cal year BP (Pindo), and 4600, 3600 and 1500 cal year BP (Baños). Examination of the chironomid and aquatic assemblages before and after the ash depositions revealed no shift in composition at Pindo, but a major change at Baños occurred after the last event around 1500 cal year BP. Chironomids at Baños changed from an assemblage dominated by Pseudochironomus and Polypedilum nubifer-type to Cricotopus/Paratrichocladius type-II, and such a dominance lasted for approximately 380 years. We suggest that, despite potential changes in the water chemistry, the major effect on the chironomid community resulted from the thickness of the tephra being deposited, which acted to shallow the water body beyond a depth threshold. Changes in the aquatic flora and fauna at the base of the trophic chain can promote cascade effects that may deteriorate the ecosystem, especially when already influenced by human activities, such as deforestation and dams, which is frequent in the high Andes

Biogeochemical factors affecting mercury methylation rate in two contaminated floodplain soils

An automated biogeochemical microcosm system allowing controlled variation of redox potential (EH) in soil suspensions was used to assess the effect of various factors on the mobility of mercury (Hg) as well as on the methylation of Hg in two contaminated floodplain soils with different Hg concentrations (approximately 5 mg Hg kg(-1) and > 30 mg Hg kg(-1)). The experiment was conducted under stepwise variation from reducing (approximately -350 mV at pH 5) to oxidizing conditions (approximately 600 mV at pH 5). Results of phospholipid fatty acids (PLFA) analysis indicate the occurrence of sulfate reducing bacteria (SRB) such as Desulfobacter species (10Me16:0, cy17:0, 10Me18:0, cy19:0) or Desulfovibrio species (18:2 omega 6,9), which are considered to promote Hg methylation. The products of the methylation process are lipophilic, highly toxic methyl mercury species such as the monomethyl mercury ion [MeHg+], which is named as MeHg here. The ln(MeHg/Hg-t) ratio is assumed to reflect the net production of monomethyl mercury normalized to total dissolved Hg (Hg-t) concentration. This ratio increases with rising dissolved organic carbon (DOC) to Hg-t ratio (ln(DOC/Hg-t) ratio) (R-2 = 0.39, p < 0.0001, n = 63) whereas the relation between ln(MeHg/Hg-t) ratio and lnDOC is weaker (R-2 = 0.09; p < 0.05; n = 63). In conclusion, the DOC/Hg-t ratio might be a more important factor for the Hg net methylation than DOC alone in the current study. Redox variations seem to affect the biogeochemical behavior of dissolved inorganic Hg species and MeHg indirectly through related changes in DOC, sulfur cycle, and microbial community structure whereas EH and pH values, as well as concentration of dissolved Fe3+/Fe2+ and Cl-seem to play subordinate roles in Hg mobilization and methylation under our experimental condition