drift theory
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Author(s):  
Ruixue Huang

Insulin resistance is a hallmark of Alzheimer’s disease (AD), type II diabetes (T2D), and Parkinson’s disease (PD). Emerging evidence indicates that these disorders are typically characterized by alterations in the gut microbiota composition, diversity, and their metabolites. Currently, it is understood that environmental hazards including ionizing radiation, toxic heavy metals, pesticides, particle matter, and polycyclic aromatic hydrocarbons are capable of interacting with gut microbiota and have a non-beneficial health effect. Based on the current study, we propose the hypothesis of “gut microenvironment baseline drift”. According to this “baseline drift” theory, gut microbiota is a temporarily combined cluster of species sharing the same environmental stresses for a short period, which would change quickly under the influence of different environmental factors. This indicates that the microbial species in the gut do not have a long-term relationship; any split, division, or recombination may occur in different environments. Nonetheless, the “baseline drift” theory considers the critical role of the response of the whole gut microbiome. Undoubtedly, this hypothesis implies that the gut microbiota response is not merely a “cross junction” switch; in contrast, the human health or disease is a result of a rich palette of gut-microbiota-driven multiple-pathway responses. In summary, environmental factors, including hazardous and normal factors, are critical to the biological impact of the gut microbiota responses and the dual effect of the gut microbiota on the regulation of biological functions. Novel appreciation of the role of gut microbiota and environmental hazards in the insulin resistance would shed new light on insulin resistance and also promote the development of new research direction and new overcoming strategies for patients.


2022 ◽  
Author(s):  
Yu Chen ◽  
Pingzhi Fang ◽  
Jian Yang ◽  
Chen Liu ◽  
Anyu Zhang ◽  
...  

Catastrophe (CAT) risk modeling of perils such as typhoon and earthquake has become a prevailing practice in the insurance and reinsurance industry. The event generation model is the key component of the CAT modeling. In this paper, a physics-based tropical cyclone (TC) full track model is introduced to model typhoons events in the western North Pacific basin. At the same time, a comprehensive test of the model is presented from the perspective of CAT risk modeling for insurance and reinsurance applications. The full track model includes the genesis, track, intensity, and landing models. Driven by the global environmental circulations, the model employs the advection and beta drift theory in atmospheric dynamics to model the track of typhoons. The proposed model is novel in the way of modeling the genesis of TCs with three-dimension kernel distributions in space and time. This enables the simulation of seasonal characteristics of TCs. By generating 10,000-year TC events, we comprehensively test the model from the standpoint of CAT insurance and reinsurance applications. The typhoon hazard model and the generated events can serve as the inputs for assessing the typhoon risk and insured loss caused by winds, rains, floods, and storm surges.


Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 657
Author(s):  
Jai S. Bolton ◽  
Hannah Klim ◽  
Judith Wellens ◽  
Matthew Edmans ◽  
Uri Obolski ◽  
...  

The antigenic drift theory states that influenza evolves via the gradual accumulation of mutations, decreasing a host’s immune protection against previous strains. Influenza vaccines are designed accordingly, under the premise of antigenic drift. However, a paradox exists at the centre of influenza research. If influenza evolved primarily through mutation in multiple epitopes, multiple influenza strains should co-circulate. Such a multitude of strains would render influenza vaccines quickly inefficacious. Instead, a single or limited number of strains dominate circulation each influenza season. Unless additional constraints are placed on the evolution of influenza, antigenic drift does not adequately explain these observations. Here, we explore the constraints placed on antigenic drift and a competing theory of influenza evolution – antigenic thrift. In contrast to antigenic drift, antigenic thrift states that immune selection targets epitopes of limited variability, which constrain the variability of the virus. We explain the implications of antigenic drift and antigenic thrift and explore their current and potential uses in the context of influenza vaccine design.


2020 ◽  
pp. 52-53
Author(s):  
Maria Júlia Barbieri

This article focuses on the experience of teaching and teaching-learning relationswith a focus on the creative processes in the Architecture and Urbanism Course, more specifically in a curricular unit of Architecture Design. The reflection proposed here takes into account the body-environment relationship as a methodological matrix for teaching and investigates the way in which students understand, interpret and act from their own body’s experiences in space. The theoretical subsidies that support this approach are related to the studies of cognition, mainly from the perspective of the embodied mind theory developed by VARELA, THOMPSON, & ROSCH (1992) in addition to JOHNSON (2007) and his theory of meaning-making, and studies developed by KASTRUP (1999) in his theory of inventiveness. We seek in these theorists the possibility of weaving a discussion that understands the process of creation as an unceasing movement of exchanges between the body and the environment. In this sense, we developed and applied a methodology that aims to explore different experiences of the body in space as mediators of the creative process in architecture. Removing students from the closed space of the classroom, getting them out of chairs and desks and returning the movement to the bodies and the rediscovery of environmental perceptions is the starting point for this methodology developed in the light of CARERI’s drift theory (2013). The drift gains a very valuable sense here, since by launching the body into space in search of unexpected encounters, we are exploring the powers of this encounter so that students can make this event a fertile field for the creation process, returning them to the fecund environment of discovery as opposed to the sterile space of the classroom. The (in) disciplinary character of this methodology, in the most radicalsense of transdisciplinarity, makes the body and space have their blurred limits, and can thus co-evolve in motion, giving rise to creative processes, in which students they invent themselves at the same time as they invent the world in which they learn. All cartographies developed in the student creation processes in this course are presented on the social network Instagram, where the work teams share their processes, appropriating the tools and languages specific to this media.


2020 ◽  
Vol 128 (3) ◽  
pp. 381-384
Author(s):  
Donika Kelly

2019 ◽  
Vol 37 (6) ◽  
pp. 1197-1222 ◽  
Author(s):  
Masatoshi Yamauchi

Abstract. Observations of the terrestrial ion escape to space and the transport of escaping ions in the magnetosphere are reviewed, with the main stress on subjects that were not covered in reviews over past 2 decades, during which Cluster has significantly improved our knowledge of them. Here, outflowing ions from the ionosphere are classified in terms of energy rather than location: (1) as cold ions refilling the plasmasphere faster than Jeans escape, (2) as cold supersonic ions such as the polar wind, and (3) as suprathermal ions energized by wave–particle interaction or parallel potential acceleration, mainly starting from cold supersonic ions. The majority of the suprathermal ions above the ionosphere become “hot” at high altitudes, with much higher velocity than the escape velocity even for heavy ions. This makes heavy hot ions more abundant in the magnetosphere than heavy ions transported by cold refilling ions or cold supersonic flow. The immediate destination of these terrestrial ions varies from the plasmasphere, the inner magnetosphere including those entering the ionosphere in the other hemisphere and the tailward outer boundaries, the magnetotail, and the solar wind (magnetosheath, cusp, and plasma mantle). Due to time-variable return from the magnetotail, ions with different routes and energy meet in the inner magnetosphere, making it a zoo of different types of ions in both energy and energy distribution. While the mass-independent drift theory has successfully disentangled this zoo of ions, there are many poorly understood phenomena, e.g., mass-dependent energization. Half of the heavy ions in this zoo also finally escape to space, mainly due to magnetopause shadowing (overshooting of ion drift beyond the magnetopause) and charge exchange near the mirror altitude where the exospheric neutral density is at its highest. The amount of heavy ions mixing directly with the solar wind is already the same as or larger than that entering into the magnetotail and is large enough to extract the solar wind kinetic energy in the cusp–plasma mantle through the mass-loading effect and drive the current system near the cusp independently of the global current system. Considering the past solar and solar wind conditions, ion escape might even have influenced the evolution of the terrestrial biosphere.


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