1,718 research outputs found
Protracted fluid-induced melting during Barrovian metamorphism in the Central Alps
The timing and dynamics of fluid-induced melting in the typical Barrovian sequence of the Central Alps has been investigated using zircon chronology and trace element composition. Multiple zircon domains in leucosomes and country rocks yield U-Pb ages spanning from âŒ32 to 22 Ma. The zircon formed during Alpine melting can be distinguished from the inherited and detrital cores on the basis of their age, Th/U (<0.1) and trace element composition. Ti-in-zircon thermometry indicates crystallization temperatures around 620-700°C. Their composition allows discriminating between (1) zircon formation in the presence of early garnet, (2) zircon in equilibrium with abundant L-MREE-rich accessory phases (allanite, titanite and apatite) typical of metatonalites, and (3) zircon formed during melting of metasediments in feldspar-dominated assemblages. The distribution of zircon overgrowths and ages indicate that repeated melting events occurred within a single Barrovian metamorphic cycle at roughly constant temperature; that in the country rocks zircon formation was limited to the initial stages of melting, whereas further melting concentrated in the segregated leucosomes; that melting occurred at different times in samples a few meters apart because of the local rock composition and localized influx of the fluids; and that leucosomes were repeatedly melted when fluids became available. The geochronological data force a revision of the temperature-time path of the migmatite belt in the Central Alps. Protracted melting over 10 My followed the fast exhumation of Alpine eclogites contained within the same region and preceded fast cooling in the order of 100°C/Ma to upper crustal levels
Oral Biofilms: Development, Control, and Analysis
The oral cavity harbors hundreds of microbial species that are present either as planktonic cells or incorporated into biofilms. The majority of the oral microbes are commensal organisms. Those that are pathogenic microbes can result in oral infections, and at times can initiate systemic diseases. Biofilms that contain pathogens are challenging to control. Many conventional antimicrobials have proven to be ineffective. Recent advances in science and technology are providing new approaches for pathogen control and containment and methods to characterize biofilms. This perspective provides (1) a general understanding of biofilm development; (2) a description of emerging chemical and biological methods to control oral biofilms; and (3) an overview of high-throughput analytical approaches to analyze biofilms
Limits of life and the habitability of Mars: The ESA space experiment BIOMEX on the ISS
BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supportsâamong othersâthe BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit
Effect of Aluminum Incorporation into Mesoporous Aluminosilicate Framework on Drug Release Kinetics
Mesoporous silica materials are promising nanocarriers for the development of drug delivery systems. In this study, the influence of pore size, volume, surface area, and doping the silica framework on the release kinetics of a model drug, metoprolol, has been studied. 20% or 50% wt. therapeutic agent was loaded into the carrier mesopores through incipient wetness impregnation. The carriers and drug-loaded samples have been characterized by small- and wide-angle X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, and nitrogen adsorption-desorption isotherms. The in vitro release profiles have been fitted using a three-parameter kinetic model and they have been explained in terms of the release rate during the burst and sustained release stages and the fraction of drug molecules released during the burst stage. The silica framework doping with aluminum was found to decrease the amount of drug released in the burst stage, without affecting the other kinetic parameters. The therapeutic agent release rates depend mainly on the pore size and volume of the mesoporous carriers and drug-loaded samples
Trauma history predicts depression and posttraumatic stress symptoms better than a psychiatric diagnosis: Comparing wartime, routine time, and early COVID-19 in Israel
Individuals with a psychiatric diagnosis and those with a history of trauma are at high risk for depression and posttraumatic stress symptoms (PTSS) following exposure to new traumatic events. Nevertheless, research is scarce on how having both a psychiatric diagnosis and a trauma history affect reactions to new traumatic events, and how different trauma types may affect individuals with a psychiatric diagnosis. We thus examined whether different stressful contexts (War and COVID-19) affected individuals with and without a psychiatric diagnosis differentially and whether results might be explained by prior trauma exposure. In the same cohort, we assessed depression and PTSS during wartime (2014), routine time (2016), and during the COVID-19 pandemic (2020) in a sample with (n = 89) and without (n = 104) a self-reported psychiatric diagnosis. This cohort was recruited during the 2014 Israel-Gaza War using social media, snowballing and outreach to mental health rehabilitation centres. We used a linear mixed modelling approach on data from the entire sample, as well as on the two study groups separately. We found that trauma history predicted PTSS and depression whereas a history of psychiatric diagnosis did not. Regarding trauma types, we found that individuals in the psychiatric diagnosis group relative to themselves had more symptoms during COVID-19 compared to war and routine time, while those without diagnosis had more PTSS and depression symptoms during wartime compared to routine time and COVID-19. In conclusion, a traumatic past may have an important influence on reactions to different types of traumatic events. Distinct traumatic events may affect individuals with or without a psychiatric diagnosis differentially
Characterization and prediction of clinical pathways of vulnerability to psychosis through graph signal processing
Causal interactions between specific psychiatric symptoms could contribute to the heterogenous clinical trajectories observed in early psychopathology. Current diagnostic approaches merge clinical manifestations that co-occur across subjects and could significantly hinder our understanding of clinical pathways connecting individual symptoms. Network analysis techniques have emerged as alternative approaches that could help shed light on the complex dynamics of early psychopathology. The present study attempts to address the two main limitations that have in our opinion hindered the application of network approaches in the clinical setting. Firstly, we show that a multi-layer network analysis approach, can move beyond a static view of psychopathology, by providing an intuitive characterization of the role of specific symptoms in contributing to clinical trajectories over time. Secondly, we show that a Graph-Signal-Processing approach, can exploit knowledge of longitudinal interactions between symptoms, to predict clinical trajectories at the level of the individual. We test our approaches in two independent samples of individuals with genetic and clinical vulnerability for developing psychosis. Novel network approaches can allow to embrace the dynamic complexity of early psychopathology and help pave the way towards a more a personalized approach to clinical care
Bericht zur Tagung "Narrative Networks: Kultur und Narration im Spannungsfeld von Fakten und Fiktionen"
Maternal immune activation transgenerationally modulates maternal care and offspring depression-like behavior
AbstractGestational infection is increasingly being recognized for its involvement as causative mechanism in severe developmental brain abnormalities and its contribution to the pathogenesis of psychopathologies later in life. First observations in the widely accepted maternal immune activation (MIA) model based upon the systemic administration of the viral mimetic Polyinosinic:polycytidylic acid (poly(I:C)) have recently suggested a transmission of behavioral and transcriptional traits across generations. Although maternal care behavior (MCB) is known as essential mediator of the transgenerational effects of environmental challenges on offspring brain function and behavior, the possible propagation of alterations of MCB resulting from MIA to following generations has not yet been examined. Here we show that poly(I:C) stimulation at embryonic day 12.5 (E12.5) leads to aberrant MCB and that this effect is transmitted to the female F1 offspring. The transgenerational effects on MCB are paralleled by enhanced depression-like behavior in the second generation F2 offspring with contributions of both maternal and paternal heritages. Examination of offspring hippocampal expression of genes known as targets of MCB and relevant for ensuing non-genetic transmission of altered brain function and behavior revealed transgenerationally conserved and modified expressional patterns in the F1 and F2 generation.Collectively these data firstly demonstrate the transgenerational transmission of the impact of gestational immune activation on the reproductive care behavior of the mother. Behavioral and molecular characteristics of first and second generation offspring suggest transgenerationally imprinted consequences of gestational infection on psychopathological traits related to mood disorders which remain to be examined in future cross-fostering experiments
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