The SARS-CoV-2/Receptor Axis in Heart and Blood Vessels: A Crisp Update on COVID-19 Disease with Cardiovascular Complications

The SARS-CoV-2 virus causing COVID-19 disease has emerged expeditiously in the world and has been declared pandemic since March 2020, by World Health Organization (WHO). The destructive effects of SARS-CoV-2 infection are increased among the patients with pre-existing chronic conditions and, in particular, this review focuses on patients with underlying cardiovascular complications. The expression pattern and potential functions of SARS-CoV-2 binding receptors and the attributes of SARS-CoV-2 virus tropism in a physio-pathological state of heart and blood vessel are precisely described. Of note, the atheroprotective role of ACE2 receptors is reviewed. A detailed description of the possible detrimental role of SARS-CoV-2 infection in terms of vascular leakage, including endothelial glycocalyx dysfunction and bradykinin 1 receptor stimulation is concisely stated. Furthermore, the potential molecular mechanisms underlying SARS-CoV-2 induced clot formation in association with host defense components, including activation of FXIIa, complements and platelets, endothelial dysfunction, immune cell responses with cytokine-mediated action are well elaborated. Moreover, a brief clinical update on patient with COVID-19 disease with underlying cardiovascular complications and those who had new onset of cardiovascular complications post-COVID-19 disease was also discussed. Taken together, this review provides an overview of the mechanistic aspects of SARS-CoV-2 induced devastating effects, in vital organs such as the heart and vessels.

Tensions, articulations, and novelty in the ontogenetic development of historical thinking: Contributions of cultural–historical psychology

To analyse or experience history, to argue or narrate it, two approaches define and explain the phenomenon of thinking about history. In recent decades, thinking about history has become especially relevant because of its relationship with citizenship, either to evaluate evidence of the past or to guide present and future action. The contributions of psychology are diverse and come from traditions that refer to apparently antagonistic psychological processes, such as narrative and argumentation. The objective of this article is to address this discussion from a cultural–historical approach, specifically Vygotskian. We propose that argumentation and narrative are psychological processes that can be developed separately in ontogeny. Both processes, under certain conditions and socially mediated action, are stressed and articulated to give way to historical thinking, a higher psychological process.

Adenosine and adenosine receptor-mediated action in coronary microcirculation

Adenosine is an ubiquitous extracellular signaling molecule and plays a fundamental role in the regulation of coronary microcirculation through activation of adenosine receptors (ARs). Adenosine is regulated by various enzymes and nucleoside transporters for its balance between intra- and extracellular compartments. Adenosine-mediated coronary microvascular tone and reactive hyperemia are through receptors mainly involving A2AR activation on both endothelial and smooth muscle cells, but also involving interaction among other ARs. Activation of ARs further stimulates downstream targets of H2O2, KATP, KV and KCa2+ channels leading to coronary vasodilation. An altered adenosine-ARs signaling in coronary microcirculation has been observed in several cardiovascular diseases including hypertension, diabetes, atherosclerosis and ischemic heart disease. Adenosine as a metabolite and its receptors have been studied for its both therapeutic and diagnostic abilities. The present review summarizes important aspects of adenosine metabolism and AR-mediated actions in the coronary microcirculation.

Mechanisms of Network Interactions for Flexible Cortico-Basal Ganglia-Mediated Action Control

In humans, finely tuned gamma synchronization (60-90 Hz) rapidly appears at movement onset in a motor control network involving primary motor cortex, the basals ganglia and motor thalamus. Yet the functional consequences of brief movement-related synchronization are still unclear. Distinct synchronization phenomena have also been linked to different forms of motor inhibition, including relaxing antagonist muscles, rapid movement interruption and stabilizing network dynamics for sustained contractions. Here I will introduce detailed hypotheses about how intra- and inter-site synchronization could interact with firing rate changes in different parts of the network to enable flexible action control. The here proposed cause-and-effect relationships shine a spotlight on potential key mechanisms of cortico-basal ganglia-thalamo-cortical communication. Confirming or revising these hypotheses will be critical in understanding the neuronal basis of flexible movement initiation, invigoration and inhibition. Ultimately, the study of more complex cognitive phenomena will also become more tractable once we understand the neuronal mechanisms underlying behavioural readouts.

Referential vs. Non-referential World-Language Relations: How Do They Modulate Language Comprehension in 4 to 5-Year-Olds, Younger, and Older Adults?

Age has been shown to influence language comprehension, with delays, for instance, in older adults' expectations about upcoming information. We examined to what extent expectations about upcoming event information (who-does-what-to-whom) change across the lifespan (in 4- to 5-year-old children, younger, and older adults) and as a function of different world-language relations. In a visual-world paradigm, participants in all three age groups inspected a speaker whose facial expression was either smiling or sad. Next they inspected two clipart agents (e.g., a smiling cat and a grumpy rat) depicted as acting upon a patient (e.g., a ladybug tickled by the cat and arrested by the rat). Control scenes featured the same three characters without the action depictions. While inspecting the depictions, comprehenders listened to a German sentence [e.g., Den Marienkäfer kitzelt vergnügt der Kater; literally: “The ladybug (object/patient) tickles happily the cat (subject/agent)”]. Referential verb-action relations (i.e., when the actions were present) could, in principle, cue the cat-agent and so could non-referential relations via links from the speaker's smile to “happily” and the cat's smile. We examined variation in participants' visual anticipation of the agent (the cat) before it was mentioned depending on (a) participant age and (b) whether the referentially mediated action depiction or the non-referentially associated speaker smile cued the agent. The action depictions rapidly boosted participants' visual anticipation of the agent, facilitating thematic role assignment in all age groups. By contrast, effects of the non-referentially cued speaker smile emerged in the younger adults only. We outline implications of these findings for processing accounts of the temporally coordinated interplay between listeners' age-dependent language comprehension, their interrogation of the visual context, and visual context influences.

Teacher Learning to Craft a Vision of Reflexive Praxis

In this chapter, the authors introduce research-based strategies to engage beginning teachers in learning as reflexive praxis, a continuous inquiry into teaching. They argue that mastery of such mediational means of reflection as verbal/visual narratives, artmaking, and dialog mediate the development of reflection as a tool-mediated action, reflexive praxis, and support teachers' transformation into agents of their praxis. The discussion concerns the development of teachers' visual narratives, from descriptive to critical, and their ability to engage in critical reflection of their practice. The cycles of verbal narrative, dialog, and visual narrative in a course of artmaking activity scaffolded the development of teachers' reflections from descriptions of the critical event in practice to critical reflection. The chapter includes a detailed protocol for a multi-media triptych activity that can be used by both teachers and teacher educators for developing teachers' reflexive praxis.

Exploring the object-sourced transmodal practices of an emergent bilingual child in sociodramatic play

This case study explores how an emergent bilingual preschooler used transmodal practices to engage with objects and compose narratives in sociodramatic play. Video recordings and field notes were collected in a dual language preschool classroom in the United States to examine the actional, verbal, and visual modes used by the focal child during his engagement with objects. An action-oriented analysis using multimodal discourse and mediated action frameworks revealed how he transmodally engaged with play artifacts to embody imagined roles and extend objects’ functionality. The child engaged with objects in three particular ways by (a) resourcing objects to advertise play to peers, (b) extending objects’ meaning potential, and (c) recruiting physical and imagined objects to elaborate on storyline. His translanguaging served as an additional compositional resource to provide contextualization for play narratives; showcase personalized meanings and underscore his multimodal intent during play; and endorse and co-opt others’ play ideas. Findings have implications for ways that early childhood teachers can use objects to promote and augment multimodal sociodramatic play scenarios.

Long-term spaceflight and the cardiovascular system

While early investigations into the physiological effects of spaceflight suggest the body's ability to reversibly adapt, the corresponding effects of long-term spaceflight (>6 months) are much less conclusive. Prolonged exposure to microgravity and radiation yields profound effects on the cardiovascular system, including a massive cephalad fluid translocation and altered arterial pressure, which attenuate blood pressure regulatory mechanisms and increase cardiac output. Also, central venous pressure decreases as a result of the loss of venous compression. The stimulation of baroreceptors by the cephalad shift results in an approximately 10%–15% reduction in plasma volume, with fluid translocating from the vascular lumen to the interstitium. Despite possible increases in cardiac workload, myocyte atrophy and notable, yet unexplained, alterations in hematocrit have been observed. Atrophy is postulated to result from shunting of protein synthesis from the endoplasmic reticulum to the mitochondria via mortalin-mediated action. While data are scarce regarding their causative agents, arrhythmias have been frequently reported, albeit sublethal, during both Russian and American expeditions, with QT interval prolongation observed in long, but not short duration, spaceflight. Exposure of the heart to the proton and heavy ion radiation of deep space has also been shown to result in coronary artery degeneration, aortic stiffness, carotid intima thickening via collagen-mediated action, accelerated atherosclerosis, and induction of a pro-inflammatory state. Upon return, long-term spaceflight frequently results in orthostatic intolerance and altered sympathetic responses, which can prove hazardous should any rapid mobilization or evacuation be required, and indicates that these cardiac risks should be especially monitored for future missions.

Modeling Direct and Indirect Action on Cell Survival After Photon Irradiation under Normoxia and Hypoxia

The demand for personalized medicine in radiotherapy has been met by a surge of mechanistic models offering predictions of the biological effect of ionizing radiation under consideration of a growing number of parameters. We present an extension of our existing model of cell survival after photon irradiation to explicitly differentiate between the damage inflicted by the direct and indirect (radicals-mediated) action of ionizing radiation. Within our approach, we assume that the oxygenation status affects the indirect action. The effect of different concentrations of dimethyl sulfoxide (DMSO), an effective radical scavenger, has been simulated at different dose levels in normoxic and hypoxic conditions for various cell lines. Our model is found to accurately predict experimental data available in literature, validating the assumptions made in our approach. The presented extension adds further flexibility to our model and could act as basis for further developments of our model.