scholarly journals Long-time persistence of hydrodynamic memory boosts microparticle transport

2019 ◽  
Author(s):  
Sean Lee Seyler ◽  
Steve Pressé
Keyword(s):  
Driving Forces ◽  
Memory Effects ◽  
Algebraic Decay ◽  
The Past ◽  
Long Time ◽  
Physical Insight ◽  
Fluid Coupling ◽  
Motion Capturing ◽  
Insight Into

In a viscous fluid, the past motion of an accelerating particle is retained as an imprint on the vorticity field, which decays slowly as t−3/2. At low Reynolds number, the Basset-Boussinesq-Oseen (BBO) equation correctly describes nonuniform particle motion, capturing hydrodynamic memory effects associated with this slow algebraic decay. Using the BBO equation, we numerically simulate driven single-particle transport to show that memory effects persist indefinitely under rather general driving conditions. In particular, when driving forces do not vary smoothly, hydrodynamic memory substantially lowers the effective transport friction. Remarkably, this enables coasting over a spatially uneven potential that otherwise traps particles modeled with pure Stokes drag. Our results provide direct physical insight into role of particle-fluid coupling in nonequilibrium microparticle transport.

scholarly journals Role of Statues in the Artistic Commemoration of African Political Leaders: Analysis of 20 Selected National Statues in African Countries

2021 ◽  
Vol 3 (1) ◽  
pp. 40-77
Author(s):  
Kamau Wango
Keyword(s):  
Public Art ◽  
The Political ◽  
Human Beings ◽  
Political Leaders ◽  
African Countries ◽  
Long Time ◽  
The Subject ◽  
Visual Impact ◽  
Insight Into

Artistic commemoration of leaders and other iconic personalities has been in existence for centuries. Statues in particular have been used as a fitting avenue for the commemoration of political leaders and other luminaries in many fields. The premise upon which statues are made is that the subjects featured initiated and attained, in their lifetimes, concrete achievements that significantly impacted upon the lives of their fellow human beings. Other criteria for commemoration include proven integrity, dedication and selflessness in the service of the country and citizens. Statues as an integral part of public art have often generated substantial controversy on various fronts in many countries. Some of these gravitate around issues such as disputed likeness, queries about the fundamental achievements cited of the subject, at times open protests on the actions, character and integrity of the subject as well as the location of the statues. Other areas of contention include the implication of the presence of statues upon the political psyche of the country and their long-time impact on history, the youth and posterity. This paper examines the extent to which African countries have embraced this mode of artistic rendition to commemorate African political leaders in a way that is commensurate to their achievements. It is outside the scope of this paper to delve into the intricate web of back-and-forth arguments about the ‘concreteness’ of the legacies of the featured leaders who are mainly founding political figures of the respective countries. The paper, however, analyses the artistic essence of the selected statues in terms of their visual impact and whether they are indeed useful in articulating the legacies of the subjects and further, whether they ultimately bear ‘enduring visual value’ that spurs conversation and insight into these legacies. Statues must, at the very least, spur debate and conversation into the legacy of the featured subject. It becomes a form of constant interrogation as history itself takes its course; controversy is not necessarily a negative occurrence since it forms part of this discourse. The concept of immortalization, which is what initiators of statues often hope for is much harder to achieve and difficult to define. The paper examines 20 statues of African political leaders in different African Countries.

National Museums, National Narratives, and Identity Politics

2017 ◽  
Author(s):  
Cristina Lleras
Keyword(s):  
Identity Politics ◽  
Resistance To Change ◽  
National Museum ◽  
Traditional Role ◽  
National Narratives ◽  
The Past ◽  
National Museums ◽  
Insight Into

The purpose of this chapter is to examine the surge of identity politics and the diversification of heritage and the tensions that arise with the traditional role of national museums that are expected to support the model of a unitary national identity through their narratives and collections. Engaging with distinct patrimonies and transformations in museums checkmates stagnant notions of heritage, but in turn, these actions might also instigate resistance to change. A case study at the National Museum of Colombia will provide an insight into competing notions of heritage, which can be understood as the relics of a material past, but may also be seen as the meanings created about the past. This analysis instigates thoughts about the role that history and historians might play in the elaboration of narratives of identity.

University Startup Accelerators: Startup Launchpads or Vehicles for Entrepreneurial Learning?

2020 ◽  
pp. 251512742093175
Author(s):  
Lynn E. Metcalf ◽  
Thomas M. Katona ◽  
Jonathan L. York
Keyword(s):  
Return On Investment ◽  
Future Research ◽  
Uniform Structure ◽  
Primary Role ◽  
Entrepreneurial Ecosystem ◽  
The Past ◽  
Mode Of Operation ◽  
The University ◽  
Insight Into

Over the past decade, universities have invested heavily in startup accelerator programs; however, their role in the university entrepreneurial ecosystem is ambiguous. Are university startup accelerators intended to educate or are they created to facilitate business starts and to contribute to regional economic development? In contrast, most private-sector startup accelerators serve a consistent and differentiated role in the entrepreneurial ecosystem—they provide programming and resources to startups to increase the probability of a return on investment. Understanding the role of university startup accelerators is an important precursor to evaluating their impact and whether or not the return is worth the considerable investment. In this study, we poll university accelerator directors to gain their perspective on the role(s) that university startup accelerators play and to identify how they are structured and operated. Our research reveals a fairly uniform structure and mode of operation. While facilitating business starts is a key role for some, it confirms education as the primary role for university startup accelerators. We outline appropriate means of assessing the learning that takes place in accelerator programs, offer insight into how these findings can help accelerator directors deliver on outcomes and demonstrate impact, and propose avenues for future research.

scholarly journals Psychological and biological background of the interaction between psoriasis and stress

2014 ◽  
Vol 155 (24) ◽  
pp. 939-948 ◽  
Author(s):  
L. János Kálmán ◽  
Xénia Gonda ◽  
Lajos Kemény ◽  
Zoltán Rihmer ◽  
Zoltán Janka
Keyword(s):  
Neurogenic Inflammation ◽  
Significant Proportion ◽  
Stress Perception ◽  
Exact Role ◽  
New Techniques ◽  
The Past ◽  
Psychotherapeutic Interventions ◽  
Objective Evidence ◽  
Long Time

Stress is considered as a major contributor to the development and exacerbation of psoriasis by a significant proportion of patients and dermatologists. As both stressor and its effects are subject-dependent, thus extremely difficult to measure, our understanding of the exact role of stress in disease development was limited for a long time. In the past decade several new studies were carried out which expanded our knowledge on the pathophysiologic processes linking stress to psoriasis via with their objective measurements and the applied new techniques. The authors review the current literature of both psychological (alexithymia, personality, affect) and biological (cortisol, epinephrine, neurogenic inflammation) factors influencing stress perception and response in psoriasis. Results of recent investigations support previous reports about the interaction between stress and psoriasis with objective evidence. Knowing how effective stress-reducing psychopharmacologic and psychotherapeutic interventions are in the treatment of psoriasis the authors hope that this review contributes to a wider acceptance of the psychosomatic attitude in everyday dermatologic practice. Orv. Hetil., 2014, 155(24), 939–948.

De (on) Verklaarbaarheid Van Fossilisatie

1998 ◽  
Vol 58 ◽  
pp. 101-109
Author(s):  
Elisabeth van der Linden
Keyword(s):  
Learning Process ◽  
Past Tense ◽  
Advanced Learners ◽  
Syntactic Structures ◽  
The Past ◽  
Knowledge Based ◽  
Long Time ◽  
Past Tenses ◽  
Different Levels

In the literature about fossilization, several definitions have been given and several explanations have been suggested for this phenomenon. I see fossilization as a long-time stagnation in the T2 learning process, leading to errors based on transfer. Fossilization is caused by sociolinguistic, pyscholinguistic and purely linguistic factors. In this paper I concentrate on the acquisition of syntactic structures and on the role of input and instruction in that process. I argue that, although in the acquisition of some syntactic structures, UG plays an important role, this does not account for the whole learning process: learners have not only to reset parameters when acquiring T2 but have to proceduralize knowledge based on the surface structure of sentences. In the case of the use of past tenses in French, many of the Dutch advanced learners of three different levels of proficiency do not acquire native-like intuitions about the use of these tenses, although input as well as instruction are thorough on this point. I suggest that the past tense system is not UG-dependent and that the instruction does not allow proceduralization of the knowledge.

scholarly journals Neural Control of Immunity in Hypertension: Council on Hypertension Mid Career Award for Research Excellence, 2019

Hypertension ◽  
2020 ◽  
Vol 76 (3) ◽  
pp. 622-628
Author(s):  
Daniela Carnevale
Keyword(s):  
Immune Response ◽  
Nervous System ◽  
Neural Control ◽  
Neural Signals ◽  
The Past ◽  
Target Organs ◽  
Long Time ◽  
The Common ◽  
The Brain

The nervous system and the immune system share the common ability to exert gatekeeper roles at the interfaces between internal and external environment. Although interaction between these 2 evolutionarily highly conserved systems has been recognized for long time, the investigation into the pathophysiological mechanisms underlying their crosstalk has been tackled only in recent decades. Recent work of the past years elucidated how the autonomic nervous system controls the splenic immunity recruited by hypertensive challenges. This review will focus on the neural mechanisms regulating the immune response and the role of this neuroimmune crosstalk in hypertension. In this context, the review highlights the components of the brain-spleen axis with a focus on the neuroimmune interface established in the spleen, where neural signals shape the immune response recruited to target organs of high blood pressure.

Oxidants and antioxidative defense

2002 ◽  
Vol 21 (2) ◽  
pp. 61-62 ◽  
Author(s):  
T Grune
Keyword(s):  
Free Radicals ◽  
Oxygen Free Radicals ◽  
Expression Patterns ◽  
Signal Transduction Pathways ◽  
Low Doses ◽  
The Past ◽  
Small Doses ◽  
Long Time ◽  
High Doses

The role of oxygen free radicals and other oxidants in several diseases has been well established over the past decade. Whereas it was long known that high doses of oxidants may damage or kill cells, the effect of low doses or long-time exposure to small flux rates of oxidants have been the focus of the free radical research until now. Here one has to take into account that most physiological and pathophysiological actions of oxidants and free radicals are based on the permanent action of small doses and flux rates. This includes effects of oxidants on signal transduction pathways and gene expression patterns. Therefore, only a few answers can be given today on the relevance of the effects of low doses of oxidants.

A “Radical” Problem: The Poor and the English Reformers in the Mid-Seventeenth Century

1990 ◽  
Vol 29 (2) ◽  
pp. 118-146 ◽  
Author(s):  
Lotte Mulligan ◽  
Judith Richards
Keyword(s):  
Seventeenth Century ◽  
Social Reform ◽  
Economic Organization ◽  
Social Differentiation ◽  
Left Wing ◽  
The Past ◽  
The Poor ◽  
Problems And Solutions ◽  
Insight Into

Debates about poverty in mid-seventeenth-century England have, for some years, been a staple of historical studies. In our own time, where the numbers of the dispossessed continue to challenge the success of current modes of social and economic organization, such an interest is understandable and to be welcomed. But the relevance of studies of past problems and solutions and their applicability to present purposes is more complex than is usually recognized.The immediate benefit of studying discussions for change in mid-seventeenth-century England is that they provide an unusual insight into how members of that society conceived of it. In particular, their observations about the problems of poverty and the role of the poor offer us an understanding of the perceived social structure, the ethical bases for social differentiation, and the degree to which the future could be envisioned as differing from the past or present. Such understandings of proposed social change are invaluable for historians wishing to grasp the underlying assumptions on which past thought and action was predicated.Past proposals for social reform, however, have also been the focus of a significantly different enquiry by historians. In order to render those past programs more comprehensible (and more directly “relevant”) to modern readers, they are often placed on a “conservative” versus “radical” continuum, one end of which has sometimes been marked “extreme left wing.” This article argues that any such classification inevitably leads to misunderstandings of the authors and of their programs and, consequently, misrepresents both to the present.

scholarly journals What is the role of depression in the discrepancy between estimated and actual iPhone use? An exploratory analysis using cubic response surface analysis

2021 ◽  
Author(s):  
Craig Sewall ◽  
Douglas Parry
Keyword(s):  
Response Surface ◽  
Digital Media ◽  
Surface Analysis ◽  
Media Use ◽  
Response Surface Analysis ◽  
Self Report ◽  
The Past ◽  
Almost All ◽  
Insight Into

The association between depression and digital media use has received substantial research and popular attention in recent years. While meta-analytic evidence indicates that there is a small, positive relationship between digital media use and depression, almost all studies rely on self-report measures of digital media use. Evidence suggests these measures are poor reflections of usage measures derived from digital trace data. Additionally, a recent study showed that the error in self-reported digital media use is likely biased systematically by factors that are fundamental to the effect being investigated: respondents’ volume of use and level of depression. The current exploratory study harnesses cubic response surface analysis—a novel analytical approach in this domain—to advance our understanding of how inaccuracies in self-report measures of digital media use can be explained by respondent attributes, in this case their level of depression and actual iPhone usage. A sample of 325 iPhone users provided estimates of their total iPhone use over the past week, their actual iPhone use as recorded by the Apple Screen Time application, and a measure of their depression (CESD-R-10). The results of the analysis indicate that depression is i.) more strongly associated with estimated than device-logged DMU; ii.) more associated with over-estimating than under-estimating of DMU; and iii.) more associated with inaccuracy at lower versus higher levels of DMU. The findings raise important questions concerning the validity of conclusions in this area and provide insight into the structure of measurement error in self-report estimates of digital media use.

scholarly journals The Role of Public-Private Partnerships in Higher Education How Tertiary Institutions in emerging Economies benefit from Public-Private Partnerships

2017 ◽  
Vol 2 (1) ◽  
pp. 1-7
Author(s):  
Ronak Warasthe
Keyword(s):  
Higher Education ◽  
Emerging Economies ◽  
Tertiary Education ◽  
Added Value ◽  
Public Private Partnerships ◽  
Tertiary Institutions ◽  
The Past ◽  
Different Types ◽  
Insight Into

Abstract The number of Public-Private Partnerships in the education sector is growing in developing and emerging economies. Traditionally governments are the main financial contributor to education however, the involvement of the private sector is an increasing one. While more established in primary and secondary education, PPPs in tertiary education are a phenomenon rather slowly growing in the past decades (Patrinos, Barrera-Osorio, & Guaqueta, 2009). There are various concepts of PPPs in higher education each targeting different goals. In order to give an insight into different types of PPPs, the typology according to Mabizela has been briefly displayed and the case of a PPP in Namibia is given. The framework of the partnership was compiled to give an outlook on the practicability of partnerships. The paper exemplifies that both partners within a PPP can benefit from the added value they may generate for their target group. Thus, the benefit depends on quality, relevance and execution of the partnership.

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