1,720,962 research outputs found
Prenatal psychological or metabolic stress increases the risk for psychiatric disorders: the “funnel effect” model
No full textAdverse stressful experiences in utero can redirect fetal brain development, ultimately leading to increased risk for psychiatric disorders. Obesity during pregnancy can have similar effects as maternal stress, affecting mental health in the offspring. In order to explain how similar outcomes may originate from different prenatal conditions, we propose a “funnel effect” model whereby maternal psychological or metabolic stress triggers the same evolutionarily conserved response pathways, increasing vulnerability for psychopathology. In this context, the placenta, which is the main mother-fetus interface, appears to facilitate such convergence, re-directing “stress” signals to the fetus. Characterizing converging pathways activated by different adverse environmental conditions is fundamental to assess the emergence of risk signatures of major psychiatric disorders, which might enable preventive measures in risk populations, and open up new diagnostics, and potentially therapeutic approaches for disease prevention and health promotion already during pregnancy
High-fat diet during adulthood interacts with prenatal stress, affecting both brain inflammatory and neuroendocrine markers in male rats
No full textPrenatal stress (PNS) affects foetal programming and, through an interaction with subsequent challenges, can increase vulnerability to mood and metabolic disorders. We have previously shown that, following PNS, adult male rats are characterized by increased vulnerability to a metabolic stressor experienced at adulthood (8-week-high-fat diet—HFD). In this study, we specifically assessed whether PNS might interact with an adult metabolic challenge to induce an inflammatory phenotype. Changes in the expression levels of inflammatory (Il-1β, Tnf-α, Il-6) and of stress response mediators (Nr3c1, Fkbp5) as well as of mood and metabolic regulators (Bdnf, Ghs-R) were investigated in the hippocampus, prefrontal cortex and hypothalamus, brain regions involved in the pathogenesis of depression and prone to inflammation in response to stress. Overall, PNS reduced the expression of Bdnf and Tnf-α, while HFD administered at adulthood counteracted this effect suggesting that PNS impinges upon the same pathways regulating responses to a metabolic challenge at adulthood. Furthermore, HFD and PNS affected the expression of both Nr3c1 and Fkbp5, two neuroendocrine mediators involved in the response to stress, metabolic challenges and in the modulation of the emotional profile (as shown by the correlation between Fkbp5 and the time spent in the open arms of the elevated plus-maze). Overall, these results indicate that the same metabolic and neuroendocrine effectors engaged by PNS are affected by metabolic challenges at adulthood, providing some mechanistic insight into the well-known comorbidity between mood and metabolic disorders
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Prenatal N-acetyl-cysteine prevents social anxiety and modulates hippocampal inflammatory-and plasticity-related genes in adolescent mice prenatally exposed to a high-fat diet
No full textHigh-fat diet (HFD) consumption during pregnancy is associated with increased oxidative stress (OS) and low-grade chronic inflammation, and may affect fetal brain development, setting the stage for increased vulnerability to mood disorders later in life [1,2]. However, the biological mechanisms underlying the negative long-term effects of maternal HFD are poorly understood. N-acetyl-cysteine (NAC) is a promising antioxidant compound [3] that has revealed beneficial effects in the treatment of psychopathology.
The aim of this study was to investigate inflammation, OS and hypothalamic-pituitary-adrenal (HPA) axis reactivity in a mouse model of maternal HFD as potential mechanisms affecting brain development and emotional behavior in the offspring. The prenatal NAC treatment was tested to prevent the negative effects of maternal HFD on adolescent offspring, an age of main vulnerability for the onset of psychopathologies.
Female C57BL/6N mice were fed either HFD (energy 5.56 kcal/g, fat 58%, carbohydrate 25.5% and protein 16.4%) or control diet (CD, energy 4.07 kcal/g, fat 10.5%, carbohydrate 73.1% and protein 16.4%) before and during pregnancy (13 weeks); after 5 weeks on diets, half of them received NAC (1g/kg) for 8 weeks, until delivery. Emotionality and social behavior of male and female adolescent offspring (35-45 days) were assessed through the elevated plus maze (EPM) and the social interaction test (SIT); HPA axis functionality was assessed measuring plasma corticosterone levels by ELISA under basal conditions and following an acute stress. Gene expression levels of CD68, Bdnf and Nrf2 were measured in hippocampus as markers of microglial activation, brain plasticity and antioxidant capacity respectively by RealTime PCR. Data were analyzed using parametric analysis of variance (ANOVA) with diet (HFD vs. CD), treatment (NAC vs. WATER), sex (females vs. males) as between subjects factors. Post hoc comparisons were performed using the Tukey’s test.
Prenatal exposure to HFD affected sociability reducing social behaviors (p<0.01, post hoc HFD-WATER vs. CD-WATER p<0.05) in the SIT and reduced exploration in the EPM (frequency of crossings p<0.01; head dipping p=0.0292; wall-rearing p=0.0255). As for the HPA axis functionality, reduced levels of basal corticosterone were found in HFD males (p<0.01, post hoc HFD-WATER vs. CD-WATER p<0.05). Moreover, prenatal HFD decreased hippocampal Bdnf levels in females (p<0.01, post hoc HFD-WATER vs. CD-WATER p<0.05), while males showed increased CD68 expression (p<0.01).
Prenatal NAC administration prevented social anxiety, restored HPA axis basal activity in males and Bdnf levels in females (p<0.01, post hoc HFD-WATER vs. HFD-NAC p<0.05). In addition, hippocampal levels of Nrf2 resulted increased in both males and females (p<0.01), suggesting that NAC may act, at least in part, through an upregulation of this important regulator of brain antioxidant defenses.
Overall, these data showed that maternal HFD induces long-term negative effects on the adolescent offspring, affecting brain, neuroendocrine system and emotional/social behavior. These effects are partially prevented by prenatal administration of NAC suggesting that immune and OS pathways may play an important role in fetal programming of mental disorders.
Funding: ERANET-NEURON-JTC-2018 Project EMBE
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