To which world regions does the valence–dominance model of social perception apply?

Over the past 10 years, Oosterhof and Todorov’s valence–dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgements of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov’s methodology across 11 world regions, 41 countries and 11,570 participants. When we used Oosterhof and Todorov’s original analysis strategy, the valence–dominance model generalized across regions. When we used an alternative methodology to allow for correlated dimensions, we observed much less generalization. Collectively, these results suggest that, while the valence–dominance model generalizes very well across regions when dimensions are forced to be orthogonal, regional differences are revealed when we use different extraction methods and correlate and rotate the dimension reduction solution

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

Dynamics of transcription factor targeting and chromatin states during reprogramming

Induced pluripotent stem cells (iPSCs) have been produced from a number of mouse and human somatic cell types, upon the enforced expression of the transcription factors (TFs) Oct4, Klf4, Sox2, and c-Myc (OKSM). Reprogramming leads to inactivation of the somatic cell program and activation of the embryonic stem (ES) cell-specific program for self-renewal and pluripotency. Cells undergoing reprogramming initially downregulate the fibroblast-associated marker Thy1, then activate the Ssea1 marker. However only Ssea1+ cells can form iPSCs and Thy1+ and Thy1- cells are refractory cells. I firstly find why some cells are refractory and how the refractory cells can be rescued. Next an efficient reprogramming mouse model generates. Then both the spatial and temporal binding properties of these transcription factors during reprogramming investigates using Chromatin Immunoprecipitation, followed by qPCR which showed different binding patterns during reprogramming. I also investigates the compaction and protection of chromatin by DNase-MLPA and ATAC- seq across the different cell populations. Finally we studied the correlation among the TF binding, chromatin changes, nucleosomes shifting and transcriptional activity. The results of this study will further our understanding of transcriptional regulation by OKSM and how gene regulatory networks transpire during cellular reprogrammin

Isolation of reprogramming intermediates during generation of induced pluripotent stem cells from mouse embryonic fibroblasts

Mature cells of the body can be reprogrammed towards a pluripotent state by forced expression of the transcription factors Oct-4, Klf-4, Sox2, and C-Myc (OKSM) at very low efficiency. To study the reprogramming process in detail the rare intermediates of the reaction need to be separated from the bulk population. Using a genetically engineered reprogrammable mouse strain we describe how to isolate intermediates from reprogramming cultures of mouse embryonic fibroblasts via antibody labeling of cell surface markers and fluorescence-activated cell sorting (FACS)

Effect of electrical stimulation of nucleus accumbens with low, median and high currents intensities on conditioned place preference induced by morphine in rats

Background: Some investigators indicated the effect of electrical or chemical stimulation on different parts of the brain and its effect on animal′s behaviors. Furthermore, drug addiction is known to be associated with dysfunction of memory and motivational systems. In this study, we aimed to evaluate the effect of electrical stimulation of nucleus accumbens (NAc) with different currents intensities on conditioned place preference (CPP) induced by morphine. Materials and Methods: Male Wistar rats were randomly divided for experimental groups (n = 8). We investigated the influence of electrical stimulation with different current intensities (low: 15 μA, median: 50 μA and high: 100 μA) on NAc with ineffective and effective dose of morphine (0.5 and 5 mg/kg, respectively) on acquisition and expression of morphine-induced place conditioning in male rats. Results: The doses of subcutaneous administration morphine (2.5 and 5 mg/kg, P < 0.05 and P < 0.001; respectively) induced CPP compared with saline group. Furthermore, our findings are showed that electrical stimulation (100 μA) of NAc suppressed morphine-induced CPP. It revealed impairment of learning and memory formation in conditioning process due to morphine administration. Conclusion: It is possible that high current intensity (100 μA) had an accompanied effect by a reversal of the increased tissue contents of dopamine and its metabolites in the NAc of morphine-induced CPP rats. Furthermore, high current intensity in combination with ineffective dose of morphine (0.5 mg/kg) increased morphine-induced CPP probability via the prove reward system

Roles of the Nucleus Accumbens (Shell) in the Acquisition and Expression of Morphine-Induced Conditioned Behavior in Freely Moving Rats

Background: The nucleus accumbens (NAc) is a part of the rewarding cortico-mesolimbic dopamine (DA) pathway. This is a heterogeneous structure divided in two sub regions termed core and shell. DA function in the NAc is critical for goal-oriented behaviors, including those motivated by drug and brain stimulation reward. In the conditioned-place preference (CPP) paradigm, a test assessing animal′s ability to associate drug-induced effects with environmental cause to quantify drug reward for example morphine. Methods: In the present study, we investigated the influence of electrical stimulation with different current intensities on (25 and 100 µA) with and without an effective dose of morphine (0.5 and 5 mg/kg) on CPP. Results: Subcutaneous administration of morphine 5 mg/kg produced significant CPP in comparison with saline group. Our findings also showed that electrical stimulation of NAc (100 µA) significantly (P < 0.01) suppressed morphine-induced CPP that reveals impaired learning and memory formation in the process of conditioning. We found that morphine-induced CPP can be successfully suppressed by current intensity (100 µA). It was probably due to decreasing of dopamine contents and its metabolites in the NAc. Current intensity (100 µA) in combination with ineffective dose of morphine (0.5 mg/kg) increased morphine-induced CPP probability via the prove reward system. Conclusions: Since stimulation of dopaminergic neurons increases tendency to dependence to morphine, therefore in the present study, the stimulation of the NAc suppressed morphine-induced CPP that this shows impairment of learning and memory formation

Haematopoietic stem cell induction by somite-derived endothelial cells controlled by meox1

Haematopoietic stem cells (HSCs) are self-renewing stem cells capable of replenishing all blood lineages. In all vertebrate embryos that have been studied, definitive HSCs are generated initially within the dorsal aorta (DA) of the embryonic vasculature by a series of poorly understood inductive events1-3. Previous studies have identified that signalling relayed from adjacent somites coordinates HSC induction, but the nature of this signal has remained elusive. Here we reveal that somite specification of HSCs occurs via the deployment of a specific endothelial precursor population, which arises within a sub-compartment of the zebrafish somite that we have defined as the endotome. Endothelial cells of the endotome are specified within the nascent somite by the activity of the homeobox gene meox1. Specified endotomal cells consequently migrate and colonize the DA, where they induce HSC formation through the deployment of chemokine signalling activated in these cells during endotome formation. Loss of meox1 activity expands the endotome at the expense of a second somitic cell type, the muscle precursors of the dermomyotomal equivalent in zebrafish, the external cell layer. The resulting increase in endotome-derived cells that migrate to colonize the DA generates a dramatic increase in chemokine-dependent HSC induction. This study reveals the molecular basis for a novel somite lineage restriction mechanism and defines a new paradigm in induction of definitive HSCs.5 page(s

A Molecular Roadmap of Reprogramming Somatic Cells into iPS Cells

Factor-induced reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) is inefficient, complicating mechanistic studies. Here, we examined defined intermediate cell populations poised to becoming iPSCs by genome-wide analyses. We show that induced pluripotency elicits two transcriptional waves, which are driven by c-Myc/Klf4 (first wave) and Oct4/Sox2/Klf4 (second wave). Cells that become refractory to reprogramming activate the first but fail to initiate the second transcriptional wave and can be rescued by elevated expression of all four factors. The establishment of bivalent domains occurs gradually after the first wave, whereas changes in DNA methylation take place after the second wave when cells acquire stable pluripotency. This integrative analysis allowed us to identify genes that act as roadblocks during reprogramming and surface markers that further enrich for cells prone to forming iPSCs. Collectively, our data offer new mechanistic insights into the nature and sequence of molecular events inherent to cellular reprogramming. [Display omitted] ► Transcriptional analysis of iPSC formation reveals biphasic process ► c-Myc/Klf4 drive first phase whereas Oct4/Sox2/Klf4 drive second phase ► Bivalent genes form gradually whereas DNA methylation changes occur late ► Refractory cells can be rescued by elevated reprogramming factor expression By sorting fibroblasts induced to reprogram to iPSCs, the molecular characteristics of cells in the early and late stages of reprogramming are revealed, as well as the attributes of the cells refractory to reprogramming. New genes that enhance reprogramming efficiency are identified

Cell Type of Origin Dictates the Route to Pluripotency

Summary: Our current understanding of induced pluripotent stem cell (iPSC) generation has almost entirely been shaped by studies performed on reprogramming fibroblasts. However, whether the resulting model universally applies to the reprogramming process of other cell types is still largely unknown. By characterizing and profiling the reprogramming pathways of fibroblasts, neutrophils, and keratinocytes, we unveil that key events of the process, including loss of original cell identity, mesenchymal to epithelial transition, the extent of developmental reversion, and reactivation of the pluripotency network, are to a large degree cell-type specific. Thus, we reveal limitations for the use of fibroblasts as a universal model for the study of the reprogramming process and provide crucial insights about iPSC generation from alternative cell sources. : Nefzger et al. find that the molecular reprogramming trajectories of fibroblasts, neutrophils, and keratinocytes have a cell-type-specific component that only fully converges in induced pluripotent stem cells. The authors also identify universal changes shared by all three cell types, including two transcriptional waves and a conserved transcriptional program involving Egr1 downregulation. Keywords: reprogramming, induced pluripotent stem cells, fibroblasts, neutrophils, keratinocytes, transcriptional dynamics, Egr