Related Phenomena Research Articles

Design for sintering – A comprehensive study on anisotropic dimensional change on sintering

This work collects as a whole the main results obtained in the Design for Sintering project, aimed at improving the effectiveness of a design procedure accounting for anisotropic dimensional change on sintering, through a deep investigation of the related phenomena and mechanisms. The project was developed in cooperation with the main European companies producing sintered components, and it is based on a huge experimental campaign. Ring-shaped parts with different characteristics were produced in different process conditions, and dimensional changes were derived from a careful reconstruction of geometry, measured in the green and sintered state. In the first part of the project, parts characterised by different geometrical parameters and different green densities were produced, using many different powder mixes, from highly shrinking to slightly swelling. The first part of the project highlighted the importance of anisotropic dimensional change in the compaction plane, and a new anisotropy parameter was proposed accordingly. In the second part of the project, the study was then focused on the anisotropy of dimensional changes in the compaction plane, as affected by different compaction strategies. The results were implemented in the design procedure, and process conditions were highlighted ensuring good agreement between real and predicted dimensions.

What Is (and Isn’t) a Product Recall?

Safety in consumer goods is maintained by product safety laws and associated regulations. However, the legislation and regulations are specific to product categories and legal jurisdictions, thus impeding one's ability to understand what a recall is and isn’t, and how it differs from related phenomena (e.g., product-harm crisis). The authors aim to provide such an understanding. They reviewed 510 reports from academics, managers, governments, and regulators; conducted interviews with 25 practitioners; and used 10 recall data sets to identify seven fundaments of recall. They synthesize the fundaments to propose a definition and a decision tree of recall, which can help inform academics, journalists, managers, lawyers, and safety advocates regarding what term is appropriate in what context. The authors apply the fundaments to identify similarities and differences between a recall and a harm crisis, the term used frequently in marketing research in association with recall. The fundaments also enable the authors to make five recommendations each for lawmakers and regulators in an effort to guide the academic and practitioner discourse on product recall.

A comprehensive guide to research protocols for collecting and coding involuntary past and future thoughts

The paper presents a comprehensive guide for researchers investigating mind-wandering and related phenomena such as involuntary past and future thinking. Examining such spontaneous cognitions presents a challenge requiring not only the use of appropriate laboratory-based procedures, but also the coding of complex qualitative data. This guide outlines two main stages of existing research protocols: data acquisition and data coding. For the former, we introduce an easily modifiable computerized version of the vigilance task, designed for broad application in studies focusing on eliciting and measuring involuntary thoughts in controlled laboratory conditions. Regarding data preparation and coding, we provide a detailed step-by-step procedure for categorizing and coding different types of thoughts, involving both participants and competent judges. Additionally, we address some of the difficulties that may arise during this categorization and coding process. The guide is supplemented by a clip demonstrating the main part of the experimental procedure and a step-by-step example of the subsequent data processing stages. We anticipate that this research guide will not only assist a broader group of researchers interested in investigating spontaneous cognition, but will also inspire future studies on spontaneous cognition and related phenomena.•There is a need for standardized approaches to working with qualitative data when investigating spontaneous thoughts.•The paper outlines a comprehensive protocol for collecting and coding involuntary past and future-oriented thoughts.•The paper also presents a detailed step-by-step procedure for data preparation and coding to categorize different types of thoughts, involving both participants and competent judges.

Doubling in Hong Kong Sign Language

Abstract The present paper provides a copy-movement analysis for doubling in Hong Kong Sign Language (HKSL). HKSL allows for the doubling of heads and phrases in an XYX pattern with the doubled element occurring clause-finally. I argue that doubled elements undergo A’-movement into Spec,FocP, attracted by a focus-feature on Foc0. The moved element then fuses with the abstract focus feature head of FocP and becomes morphologically distinct from the lower element. This research provides a uniform account of two related phenomena, namely doubling and right dislocation, by considering head-to-spec movement. Finally, doubling in HKSL has not been previously described, and therefore my account adds to the typological picture of doubling in sign and spoken languages. This is especially important because HKSL allows for the doubling of both heads and phrases, which sets it apart from earlier accounts on doubling in other sign languages.

On the Functional Convergence of Pragmatic Markers in Arizona Spanish

Tags, compared to other types of pragmatic markers (PMs), are typically considered as separate yet related phenomena and are usually differentiated by their syntactic positions and discourse functions, among other factors. The current work explores this differentiation utilizing 36 sociolinguistic interviews with Spanish-English bilinguals in southern Arizona, USA. Standard language variation and change (LVC) methodologies were used in the extraction, coding, and statistical analyses of this dataset (n = 591), with four PM variants identified for study through an exploratory methodology: the tags no and qué no and the discourse markers (DMs) you know and saber. The results of our analyses indicate that, while utterance position, self-reported gender, and length of residence were all significant in the multivariate analysis, discourse function was dropped from the statistical model. Therefore, we interpret this finding as an indication that functional differences between these two pragmatic resources have been levelled through grammaticalization, demonstrating that for Arizona Spanish, tags and DMs belong in the same functional category of PMs. Furthermore, an analysis of codeswitching behavior triggered by the incoming variant you know demonstrates that it is becoming incorporated into the Spanish pragmatic system, patterning similarly to its counterpart saber in terms of function and position, without attrition of the native variant.

Transonic compressor Darmstadt Open Test Case – unsteady aerodynamics and stall inception

Predicting unsteady aerodynamics and related phenomena in the vicinity of the stability limit of transonic compressors has been a challenging topic within the turbomachinery community since decades. To improve numerical tools and prediction capabilities the Transonic Compressor Darmstadt Open Test Case has been introduced to provide a reliable validation test data set for steady and unsteady compressor aerodynamics. This work investigates the unsteady aerodynamics before the occurrence of rotating stall within the TU Darmstadt OpenStage compressor rotor and introduces unsteady wall pressure data to the Darmstadt Open Test Case. Exemplary pre-stall aerodynamics and stall inception are investigated for nominal (transonic) and part speed (subsonic) operating conditions, comprising the analysis of the unsteady static pressure field at the rotor tip as well as spectral analysis of the corresponding pressure signals during transient throttling maneuvers. To capture the rotor tip flow field, the rotor casing is instrumented with axially arranged flush mounted time-resolving wall pressure transducers. To determine propagation speeds of occurring phenomena, additional circumferentially distributed sensors are considered. Vibration monitoring shows no significant flutter or non-synchronous blade vibration, prior to the occurrence of rotating stall. Thus, this work focuses on aerodynamics, such as the interaction of secondary flow and shocks.

Improvement of agave bagasse hydrolysates processing under a biorefinery approach

SummaryThe economic viability of producing second-generation bioethanol from agave bagasse (AB) is influenced by the presence of phenolic compounds in the hydrolysates used during fermentation. These compounds substantially constrain the growth in yeasts that convert sugars into bioethanol, thus becoming a limitation for the process. In this study, it was proposed to select an effective adsorbent matrix to remove and recover phenolic compounds from AB hydrolysates. The related adsorption phenomena and processes were described and characterized. Four adsorbents were examined, including activated carbon (CA), as well as three polymeric matrices (MN-102, ADS-800EP, and SP825L). The adsorption parameters, such as maximum equilibrium adsorption capacity (qmax) and percent desorption, were determined through adsorption–desorption experiments in batch systems. Additionally, the impact of removing phenolic compounds on bioethanol yield was evaluated and the potential use of the recovered phenols as biopesticides against plant pathogens, such as fungi and nematodes, was explored. The results showed that activated carbon has a higher phenol adsorption capacity (qmax = 118.1 mg/g) but a lower desorption capacity (59.46 %), meanwhile, the MN-102 matrix displayed comparable adsorption characteristics and superior desorption capacity (95.81 %), rendering it the most appropriate for the process. Subsequently, the detoxification of the AB hydrolyzate, by phenolic compounds remotion, on bioethanol yield was assessed and resulted in a significant increase (3.5-fold). Finally, the fungicidal potential of the recovered phenolic compounds was evaluated on Fusarium oxysporum and Alternaria alternata, while the nematicidal activity was tested on Meloidogyne incognita. The phenolic compounds exhibited high antifungal activity against F. oxysporum (73.91 %) and moderate activity against A. alternata (40 %), in comparison to the positive control. Moreover, they showed very high nematicidal activity, causing 91.23 % mortality in M. incognita. These findings allow to conclude that incorporating the adsorption stage not only enhances bioethanol yields but also enables the efficient recovery of potentially valuable molecules.

Effects of autotaxin and lysophosphatidic acid deficiencies on depression-like behaviors in mice exposed to chronic unpredictable mild stress

The involvement of lipids in the mechanism of depression has triggered extensive discussions. Earlier studies have identified diminished levels of lysophosphatidic acid (LPA) and autotaxin (ATX) in individuals experiencing depression. However, the exact significance of this phenomenon in relation to depression remains inconclusive. This study seeks to explore the deeper implications of these observations. We assessed alterations in ATX and LPA in both the control group and the chronic unpredictable mild stress (CUMS) model group. Additionally, the impact of ATX adeno-associated virus (AAV-ATX) injection into the hippocampus was validated through behavioral tests in CUMS-exposed mice. Furthermore, we probed the effects of LPA on synapse-associated proteins both in HT22 cells and within the mouse hippocampus. The mechanisms underpinning the LPA-triggered shifts in protein expression were further scrutinized. Hippocampal tissues were augmented with ATX to assess its potential to alleviate depression-like behavior by modulating synaptic-related proteins. Our findings suggest that the decrement in ATX and LPA levels alters the expression of proteins associated with synaptic plasticity in vitro and in vivo, such as synapsin-I (SYN), synaptophysin (SYP), and brain-derived neurotrophic factor (BDNF). Moreover, we discerned a role for the ERK/CREB signaling pathway in mediating the effects of ATX and LPA. Importantly, strategic supplementation of ATX effectively mitigated depression-like behaviors. This study indicates that the ATX-LPA pathway may influence depression-like behaviors by modulating synaptic plasticity in the brains of CUMS-exposed mice. These insights augment our understanding of depression's potential pathogenic mechanism in the context of lipid metabolism and propose promising therapeutic strategies for ameliorating the disease.

Package wars and mouse movers: on the media escalation of remote-work during the COVID-19 global pandemic

ABSTRACT This paper looks at media escalations between different kinds of workers during and after the COVID-19 global pandemic. Combining post-Autonomist Marxist and media theoretical approaches, I argue that the ‘Glitter Bomb vs Porch Pirates’ video series, and related phenomena, point to the unique role that networked and computational media play in both the material enactment and cultural-symbolic valorisation of different kinds of work in relatively affluent postindustrial capitalist settings. Mark Rober, the creator of the ‘Glitter Bomb vs Porch Pirates’ video series, demonstrates how those who enjoy a relatively privileged positionality under post-Fordism actively participate in the medialogical defining and detecting of different kinds of ‘enemies’ as a form of both work and leisure. Overemployed.com and automatic mouse-movers, meanwhile, exemplify more tactical approaches to this broader set of conditions, wherein workers utilise networked and computational media to appear ‘visible’ as productive workers according to the criteria via which they are regularly detected and evaluated. Noting a common subjective framework undergirding these various examples, I conclude by highlighting the work of various media scholars focused on the question of what a truly alternative instantiation of networked and computational systems might entail.

Wellbeing in the age of virtual teams and workplace automation – a systematic review and future research agenda

Purpose In the wake of the COVID-19 pandemic organisations are adapting to a new environment of global talent shortages, economic uncertainty and geo-political turmoil. As an outcome, the organisational strategies of digital transformation and remote working have been accelerated in the race to boost innovation, competitivity and attract staff. This has led to the rise of two new organisational dynamics: the increase of virtual teams (VTs) and focus on widespread work automation. However, despite the rise of these two related phenomena, literature does not connect them as one research area, and there is a gap in the understanding of the new employee wellbeing needs they form and how to respond to them. This paper aims to bridge this gap through a systematic literature across these areas. Design/methodology/approach This paper conducts a systematic literature review across the areas of leadership, VTs and automation over the past three years. Findings In this review, a number of newly arising employee wellbeing needs are identified such as fear of job displacement, a lack of self-efficacy and social cohesion, poor relationships with leaders and more. In addition, this paper recommends three fundamental research gaps to be addressed by future studies: 1. How to build and cultivate the new leadership skills needed to support VTs and workplace automation? 2. How to design work in a way that caters for employee wellbeing needs when operating in VTs or hybrid teams and working on or with workplace automation? 3. How to design work in a way that builds and emphasises the new employee skillsets to support augmentation and solves for the new employee wellbeing needs experienced by workplace automation? Originality/value This paper provides a novel contribution to literature by centralising current schools of thought across the cross-disciplinary themes and synthesising literature to recommend new wellbeing and leadership skills for organisations to focus on, alongside producing a new research agenda for scholars to focus.

Stability in social networks.

Dunbar's number is the cognitive limit of human beings to maintain stable relationships with other individuals in their social networks, and it is found to be 150. It is based on the neocortex size of humans. Usually, Dunbar's number and related phenomena are studied from the perspective of an individual. Dunbar's number also plays a crucial role in evolutionary psychology and allied areas. However, no study done so far has considered a couple who are in a stable relationship as a system from the perspective of Dunbar's number and its hierarchy layers. In this paper, we study the impact of Dunbar's number and Dunbar's hierarchy from the perspective of a couple by studying mathematically the conjoint Dunbar graphs for a couple. The cost of romance is the loss of almost two people from one's support network when a human being enters into a new relationship. Thus, we obtain mathematically that there is no significant change in one's friendship if human beings spend negligible time with their partners. Also, along with marriage and friendship development, we attempt to assess how a person's social network structure holds up over the course of a romantic relationship. The stability of personal social networks is discussed through soft set theory and balance theoretic approach.

An analysis of reinstatement after extinction of a conditioned taste aversion.

Taste aversion learning has sometimes been considered a specialized form of learning. In several other conditioning preparations, after a conditioned stimulus (CS) is conditioned and extinguished, reexposure to the unconditioned stimulus (US) by itself can reinstate the extinguished conditioned response. Reinstatement has been widely studied in fear and appetitive Pavlovian conditioning, as well as operant conditioning, but its status in taste aversion learning is more controversial. Six taste-aversion experiments with rats therefore sought to discover conditions that might encourage it there. The results often yielded little to no evidence of reinstatement, and we also found no evidence of concurrent recovery, a related phenomenon in which responding to a CS that has been conditioned and extinguished is restored if a second CS is separately conditioned. However, a key result was that reinstatement occurred when the conditioning procedure involved multiple closely spaced conditioning trials that could have allowed the animal to learn that a US presentation signaled or set the occasion for another trial with a US. Such a mechanism is precluded in many taste aversion experiments because they often use very few conditioning trials. Overall, the results suggest that taste aversion learning is experimentally unique, though not necessarily biologically or evolutionarily unique. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Epistemic Autonomy and the Shaping of Our Epistemic Lives

ABSTRACT I present an account of epistemic autonomy as a distinctively wide-ranging epistemic virtue, one that helps us to understand a range of phenomena that might otherwise seem quite disparate – from the appropriate selection of epistemic methods, stances and topics of inquiry, to the harms of epistemic oppression, gaslighting and related phenomena. The account draws on four elements commonly incorporated into accounts of personal autonomy: (i) self-governance, (ii) authenticity, (iii) self-creation and (iv) independence. I further argue that for a distinctively epistemic virtue of autonomy; the above elements must ultimately reliably lead to valuable epistemic goods (for the agent herself and others). I then turn to the domains or ways in which epistemic autonomy so understood, can be made manifest. I suggest that epistemic autonomy is a virtue that allows us to appropriately choose (i) subject matters and areas of inquiry, (ii) methods, sources, and processes of belief formation, (iii) epistemic goals and (iv) epistemic stances or frameworks. So understood, epistemic autonomy has a role to play in shaping most every aspect of our epistemic lives.

The Image and Appearance of a Citizen as Objects of Civil Rights: The Relationship of Concepts

Introduction: the scientific paper solves the problem of the correlation of categories of appearance and image of a citizen as objects of civil rights. The author has established the interrelation and interdependence of the appearance and image of a citizen, as well as the identity and features of these intangible benefits, which are objects of relevant personal non-property rights, allowing solving the problem of establishing the legal regime of these objects. The analysis of the positions of representatives of the scientific community on the assessment of the independent legal nature of the image of a citizen in the context of its relationship with the appearance is carried out. It is stated that there is no unified approach to assessing the relationship between the right to image and the right to appearance; there is no unified approach to determining the object mediating these personal non-property rights. The purpose of the work is to solve the problem of the correlation of the legal categories of appearance and image as objects of civil rights by identifying the criteria for their differentiation, substantiating their independent nature based on the established features. Methods: the purpose of the study has determined the use of the dialectical method of scientific cognition in the analysis of the problem of interest, in its entirety using the methods of analysis and synthesis. Results: based on the studied scientific positions, as well as the provisions of the legislation, the different legal nature of the categories of appearance and image as objects of civil rights is established. The criteria allowing distinguishing the specified objects are revealed. The results of the study will serve as a basis for further doctrinal research of these related phenomena of private law science. Conclusions: based on the revealed differences, it is justified that appearance and image are different objects of civil rights. The citizen’s right to the inviolability of the image and the right to appearance are not in a relationship of subordination, and one right does not condition the other, and these rights have an independent legal nature from each other, which is expressed in the special objects of legal protection, the specifics of the focus of protection of these rights and various legal regimes for the protection of these rights. The concept of the image of a citizen as an object of civil rights is formulated.

Dynamic Tangled Derivative Logic of Metric Spaces

Dynamical systems are abstract models of interaction between space and time. They are often used in fields such as physics and engineering to understand complex processes, but due to their general nature, they have found applications for studying computational processes, interaction in multi-agent systems, machine learning algorithms and other computer science related phenomena. In the vast majority of applications, a dynamical system consists of the action of a continuous `transition function' on a metric space. In this work, we consider decidable formal systems for reasoning about such structures. Spatial logics can be traced back to the 1940's, but our work follows a more dynamic turn that these logics have taken due to two recent developments: the study of the topological mu-calculus, and the the integration of linear temporal logic with logics based on the Cantor derivative. In this paper, we combine dynamic topological logics based on the Cantor derivative and the `next point in time' operators with an expressively complete fixed point operator to produce a combination of the topological mu-calculus with linear temporal logic. We show that the resulting logics are decidable and have a natural axiomatisation. Moreover, we prove that these logics are complete for interpretations on the Cantor space, the rational numbers, and subspaces thereof.

“SLAPPed” and censored? Legal threats and challenges to press freedom and investigative reporting

The issue of SLAPPs remains a largely understudied area in journalism studies. Limited academic work on the topic mainly focuses on its legal aspects and there is little empirical academic work engaging with the way SLAPPs are experienced by those who are personally involved. This study focuses on illuminating the impact of these vexatious and frivolous lawsuits on investigative journalism and press freedom, and recording whether journalists experience additional or different consequences from SLAPPs in comparison to other types of threats. Based on interviews with journalists who have experienced SLAPPs in recent years and documenting their personal experiences, the study sheds light on the hidden professional and personal costs of investigative reporting, attempts to assess this phenomenon in relation to its effects on journalism and journalists, and is one of the few to record and analyze journalists’ personal beliefs and experiences.

The Effect of Oropharyngeal Resting Tremor on Swallowing Function in a Clinical Cohort of People with Parkinson's Disease.

Parkinson's Disease (PD) is a progressive neurodegenerative disease, with hallmark symptomology typically consisting of tremor, bradykinesia, and rigidity. Though the classic "pill-rolling" rest tremor in the hand or upper limb are often the most salient, it can occur throughout the body including the lower limbs, jaw, face, or tongue. There have been investigations into other motor related phenomena potentially affecting swallow function in PwPD previously. However, there have been no investigations of how oropharyngeal resting tremor in structures such as the tongue or larynx explicitly affects swallowing physiology. A retrospective analysis of previously conducted VFSS on 34 patients diagnosed with idiopathic PD (IPD) was performed to examine how individuals that displayed resting tremor during VFSS (Tremor +) and those who did not (Tremor-) differ in swallowing function. Measures of swallowing function including timing intervals of key swallow events, post-swallow residue, and penetration-aspiration scale (PAS) scores were recorded, and key demographic information including time since diagnosis and medication status were extracted from the medical records available. Multivariate models were used to identify differences between tremor groups for timing intervals and post-swallow residue, and chi-squares were computed for differences in PAS score distribution by group and bolus. Sixty-eight percent (23/34) of this sample displayed oropharyngeal resting tremor in at least one structure during VFSS. There were no instances of other tremor types observed in this sample. All participants were taking medication to manage PD symptomology. Significant effects of tremor group were observed for swallow timing intervals related to airway closure (p < 0.001), post-swallow residue (p < 0.05), and swallow safety at the bolus level in the Tremor + group (p < 0.001). These results suggest that PwPD who present with resting tremor in oropharyngeal structures may manifest with different variations in swallowing physiology, including altered timings of swallow events, increased pharyngeal residue, and greater associations of airway invasion with thinner and larger volume boluses. This study highlights the need for substantially more research into how motor fluctuations and phenotypes of PwPD contribute to alterations in swallowing function.

Prevention and counteraction of mobbing in labor relations: regulatory and legal support in Ukraine

The article examines the legislative regulation of the concept and forms of mobbing, responsibility for committing such acts. Attention is drawn to the fact that the problem of mobbing is relevant not only for our country, where it is increasingly possible to observe cases of this phenomenon at work (harassment of an employee by both colleagues, subordinates, and management), but also for European countries, where they know what is mobbing and have long since legally regulated the issue of preventing and countering this phenomenon. It is noted that Ukraine has also joined European countries in this matter by adopting the Law "On Amendments to Certain Legislative Acts of Ukraine on Prevention and Counteraction to Mobbing (bullying)” dated 11.16.2022 No. 2759-IX, which brought the norms of Ukrainian legislation in accordance with European and provided protection against discrimination and psychological pressure in the workforce. It is noted that the legislative regulation of the concept and forms of mobbing, responsibility for committing such acts will contribute to the protection and protection of the rights of employees, as well as overcoming mobbing as a negative phenomenon in labor relations. At the same time, it was concluded that despite the fact that the concept of "mobbing” is legally defined, the responsibility for it, many issues still remain today, which need to be resolved. Since the amendments to the legislation gave birth to many aspects that were not familiar either to the practice or to the science of domestic labor law. Yes, now the psychological and economic pressure of employees has become an additional reason for terminating the employment contract; the regulation of mobbing established new areas of employer responsibility, and also gave rise to many unanswered questions - how to distinguish bullying from a joke; whether to consider the use of obscene language as mobbing; is it considered mobbing when an employee compares his work with the work of another employee and complains about being overworked compared to a colleague; where the line will be drawn between the employer's legal requirement for the employee to perform the job well and mobbing the employee and many others. There is also an objective need to develop a legal mechanism to protect employees from mobbing, which would provide legal certainty regarding this phenomenon in labor relations.

Research in the Department of Music Technology and Acoustics of the Hellenic Mediterranean University: An Overview and Prospects

The Department of Music Technology and Acoustics of the Hellenic Mediterranean University offers a unique higher education program in Greece, addressing the growing demand for specialists in music technology, sound technology, and acoustics. It aims to educate specialized professionals in the rapidly advancing scientific fields of music technology and acoustics, mainly driven by the swift progress in electronic technology. The Department aims to address a gap in the professional market by producing highly skilled graduates, capable not only of keeping up with the latest scientific and technological developments but also of leading the way by introducing innovative approaches and methods. The Department combines art, science, and technology, focusing on sound recording, analysis, synthesis, and music production. Music technology encompasses various cutting-edge fields such as network music performance, artificial intelligence in music, and music embodiment. Acoustics refers to fundamental aspects of sound as well as its generation, transmission, and related phenomena. It includes research fields such as physical acoustics, optoacoustics, and vibroacoustics. This overview presents the research activities, methodologies, and results. A discussion of future research works and pointers to future technological evolution towards real-world music and acoustics applications is also provided.

Back to the Future: Immune Protection or Enhancement of Future Coronaviruses.

Before the emergence of SARS-CoV-1, MERS-CoV, and most recently, SARS-CoV-2, four other coronaviruses (the alpha coronaviruses NL63 and 229E and the beta coronaviruses OC43 and HKU1) had already been circulating in the human population. These circulating coronaviruses all cause mild respiratory illness during the winter seasons, and most people are already infected in early life. Could antibodies and/or T cells, especially against the beta coronaviruses, have offered some form of protection against (severe) COVID-19 caused by infection with SARS-CoV-2? Related is the question of whether survivors of SARS-CoV-1 or MERS-CoV would be relatively protected against SARS-CoV-2. More importantly, would humoral and cellular immunological memory generated during the SARS-CoV-2 pandemic, either by infection or vaccination, offer protection against future coronaviruses? Or rather than protection, could antibody-dependent enhancement have taken place, a mechanism by which circulating corona antibodies enhance the severity of COVID-19? Another related phenomenon, the original antigenic sin, would also predict that the effectiveness of the immune response to future coronaviruses would be impaired because of the reactivation of memory against irrelevant epitopes. The currently available evidence indicates that latter scenarios are highly unlikely and that especially cytotoxic memory T cells directed against conserved epitopes of human coronaviruses could at least offer partial protection against future coronaviruses.