scholarly journals Design principles of hair-like structures as biological machines

2018 ◽  
Vol 15 (142) ◽  
pp. 20180206 ◽  
Author(s):  
Madeleine Seale ◽  
Cathal Cummins ◽  
Ignazio Maria Viola ◽  
Enrico Mastropaolo ◽  
Naomi Nakayama

Hair-like structures are prevalent throughout biology and frequently act to sense or alter interactions with an organism's environment. The overall shape of a hair is simple: a long, filamentous object that protrudes from the surface of an organism. This basic design, however, can confer a wide range of functions, owing largely to the flexibility and large surface area that it usually possesses. From this simple structural basis, small changes in geometry, such as diameter, curvature and inter-hair spacing, can have considerable effects on mechanical properties, allowing functions such as mechanosensing, attachment, movement and protection. Here, we explore how passive features of hair-like structures, both individually and within arrays, enable diverse functions across biology. Understanding the relationships between form and function can provide biologists with an appreciation for the constraints and possibilities on hair-like structures. Additionally, such structures have already been used in biomimetic engineering with applications in sensing, water capture and adhesion. By examining hairs as a functional mechanical unit, geometry and arrangement can be rationally designed to generate new engineering devices and ideas.

2021 ◽  
Vol 1 ◽  
pp. 3219-3228
Author(s):  
Koray Benli ◽  
Jonathan Luntz ◽  
Diann Brei ◽  
Wonhee Kim ◽  
Paul Alexander ◽  
...  

AbstractPneumatically activated systems enable myriad types of highly functional inflatables employing a wide range of architectural approaches affecting their form and function, making systematic conceptual design difficult. A new architectural class of pneumatically activated systems, constrained layer inflatable systems, consists of hierarchically architected flat layers of thin airtight bladders that are internally and/or externally constrained to generate a variety of functionalities. The highly hierarchical architectural structure of constrained layer inflatable systems coincides with the hierarchy of produced functions, providing an opportunity for the development of a functional architectural decomposition, capturing the inherent relationship between architectural and functional hierarchies. The basis of the approach is conveyed through the design of an example constrained layer inflatable system. This approach empowers the systematic understanding of the interrelated architectural and functional breakdown of constrained layer inflatable systems, enabling designers to iteratively analyze, synthesize, and re-synthesize the components of the system improving existing designs and exploring new concepts.


Transilvania ◽  
2021 ◽  
pp. 75-84
Author(s):  
Mona Arhire

Emphasis, a well-acknowledged stylistic device, is a carrier of a considerable load of emotional content in the fictional dialogue. Its manifestation can take sundry forms and can be attached to a wide range of feelings and can take different degrees of intensity, all of which determines the creation of the atmosphere and impacts the reception by the readership. This paper reports on the investigation of the occurrence of emphasis embedded in the dialogic utterances of John Fowles’ novel Mantissa. The focus lies on the relation between the formal construction of emphatic sentences and the functional values deriving therefrom. The study entails a comparative analysis of emphatic utterances depicted from the English original text and its translation into Romanian. The three research questions refer to the comparative-contrastive realization of emphatic sentences in the two languages, to the extent to which the functional component succeeds in being transferred to the target language and to possible means of compensation when structural differences pose translational problems. The analysis is structured along a typology of sentences adapted to the nature of the text under scrutiny and to the aims of this study. The findings and conclusions ultimately indicate the importance of establishing a relation between form and function in matter of emphasis in the literary dialogue as an act of communication depending on linguistic devices for its effectiveness.


2018 ◽  
Author(s):  
Stephen Wilks

Cornell International Law Journal: Vol. 50 : No. 2 , Article 4.Using law to conscript financial technology in aid of state goals is not new. Financial institutions have long been subject to myriad legal and regulatory reporting requirements designed to combat money laundering, enforce economic sanctions, support tax compliance, and interdict the financing of terrorism. Trump's particular approach to this tradition, however, seeks to capitalize on a particularly toxic convergence of race, class, economics, and globalization. America is not alone in its recent experience with surges in right wing, nationalist populism. Globalism's winds have posed challenges to those who have enjoyed the benefits of protectionist trade policies that no longer exist, placing them on a collision course with diaspora migrants from the poorest countries who are now mobile, thanks to financial technologies that ease the process of remitting funds home. This collision is a complicated alchemy, which lays bare the ways in which populist faith in the free market appears to be eroding under the strain of globalization's effects. In politicizing migrant remittance flows to Mexico, Donald Trump has signaled both a political recognition of this erosion and a willingness to exploit it. In doing so, he has done more than simply peddle a narrative that appeals to a base of voters increasingly dissatisfied with America's political class. He has likely prompted a new set of considerations among diaspora communities anxious to preserve existing remittance flows in the face of intense anxiety about America's working poor. Yet this conflict demonstrates how modem payment platforms now serve a range of functions one might have seen in a medieval town square: they facilitate commerce while serving as points of conflict and as places of protest. Every possible kind of human and institutional actor passes through this square, shaping its form and function, whether deliberately or unwittingly. The respective aspirations of globalism's human casualties are a deeply complex ecology-reflecting a range of outlooks in relation to one another. On the heels of a presidential campaign defined by explicitly divisive rhetoric transcending the traditional limits of dog-whistle politics, dismissive attitudes towards Trump's campaign proposal have crystalized into palpable fears among progressives who now worry about the potential of witnessing the deployment of proposals that once seemed unlikely. Whether or not President Trump ultimately expands federal regulations to require proof of lawful presence in the country as a precondition of access to international remittance services may matter less than the consequences of linking these transactions to undocumented immigrants in the minds of the white working class.


Author(s):  
Jashan P. Singh ◽  
Jennifer L. Young

AbstractMechanical forces in the cardiovascular system occur over a wide range of length scales. At the whole organ level, large scale forces drive the beating heart as a synergistic unit. On the microscale, individual cells and their surrounding extracellular matrix (ECM) exhibit dynamic reciprocity, with mechanical feedback moving bidirectionally. Finally, in the nanometer regime, molecular features of cells and the ECM show remarkable sensitivity to mechanical cues. While small, these nanoscale properties are in many cases directly responsible for the mechanosensitive signaling processes that elicit cellular outcomes. Given the inherent challenges in observing, quantifying, and reconstituting this nanoscale environment, it is not surprising that this landscape has been understudied compared to larger length scales. Here, we aim to shine light upon the cardiac nanoenvironment, which plays a crucial role in maintaining physiological homeostasis while also underlying pathological processes. Thus, we will highlight strategies aimed at (1) elucidating the nanoscale components of the cardiac matrix, and (2) designing new materials and biosystems capable of mimicking these features in vitro.


2015 ◽  
Vol 12 (107) ◽  
pp. 20150184 ◽  
Author(s):  
Z. Jack Tseng ◽  
John J. Flynn

Morphology serves as a ubiquitous proxy in macroevolutionary studies to identify potential adaptive processes and patterns. Inferences of functional significance of phenotypes or their evolution are overwhelmingly based on data from living taxa. Yet, correspondence between form and function has been tested in only a few model species, and those linkages are highly complex. The lack of explicit methodologies to integrate form and function analyses within a deep-time and phylogenetic context weakens inferences of adaptive morphological evolution, by invoking but not testing form–function linkages. Here, we provide a novel approach to test mechanical properties at reconstructed ancestral nodes/taxa and the strength and direction of evolutionary pathways in feeding biomechanics, in a case study of carnivorous mammals. Using biomechanical profile comparisons that provide functional signals for the separation of feeding morphologies, we demonstrate, using experimental optimization criteria on estimation of strength and direction of functional changes on a phylogeny, that convergence in mechanical properties and degree of evolutionary optimization can be decoupled. This integrative approach is broadly applicable to other clades, by using quantitative data and model-based tests to evaluate interpretations of function from morphology and functional explanations for observed macroevolutionary pathways.


2014 ◽  
Vol 88 (4) ◽  
pp. 633-635 ◽  
Author(s):  
Imran A. Rahman ◽  
Selena Y. Smith

‘Virtual paleontology’ entails the use of computational methods to assist in the three-dimensional (3-D) visualization and analysis of fossils, and has emerged as a powerful approach for research on the history of life. Three-dimensional imaging techniques allow poorly understood or previously unknown anatomies of fossil plants, invertebrates, and vertebrates, as well as microfossils and trace fossils, to be described in much greater detail than formerly possible, and are applicable to a wide range of preservation types and specimen sizes (Table 1). These methods include non-destructive high-resolution scanning technologies such as conventional X-ray micro-tomography and synchrotron-based X-ray tomography. In addition, form and function can be rigorously investigated through quantitative analysis of computer models, for example finite-element analysis.


2009 ◽  
Vol 297 (4) ◽  
pp. F849-F863 ◽  
Author(s):  
Paul A. Welling ◽  
Kevin Ho

The discovery of the renal outer medullary K+channel (ROMK, Kir1.1), the founding member of the inward-rectifying K+channel (Kir) family, by Ho and Hebert in 1993 revolutionized our understanding of potassium channel biology and renal potassium handling. Because of the central role that ROMK plays in the regulation of salt and potassium homeostasis, considerable efforts have been invested in understanding the underlying molecular mechanisms. Here we provide a comprehensive guide to ROMK, spanning from the physiology in the kidney to the organization and regulation by intracellular factors to the structural basis of its function at the atomic level.


Comunicar ◽  
2015 ◽  
Vol 23 (45) ◽  
pp. 95-104 ◽  
Author(s):  
Mariano Sánchez-Martínez ◽  
Matthew Kaplan ◽  
Leah Bradley

Nowadays, as ageing increases in Western societies it has become more evident that multiple generations are ageing concurrently at any given time in history. Therefore, ageing must be approached as a multi-generational phenomenon, not just as a question of elders. In this context, situations that engender increased interactions between generations are garnering more attention. There is a growing emphasis on expanding the role of technology in intergenerational programmes, within the field of intergenerational studies. Consequently, this paper is focused on education and learning processes within intergenerational programmes with a strong technology component. Information from a total of 46 intergenerational programmes from 11 countries has been gathered through a survey. Level of impact, status of generational groups, and centrality of technology have been appraised for all programmes in the sample. Technology learning-teaching constitute the main area of intended impact of these programmes. However, the surveyed programmes employ as well a wide range of strategies to facilitate intergenerational communication, cooperation and relationship formation between generations involved. Interest of programmes examined does not just consist of teaching the use technology but of experimenting with technology in different forms and functions and exploring the positive potential for enhancing intergenerational relationships Actualmente, conforme el envejecimiento en las sociedades occidentales aumenta, resulta más evidente que en cualquier momento histórico dado hay varias generaciones envejeciendo simultáneamente. Por tanto, el envejecimiento debe ser estudiado como fenómeno multi-generacional y no solo como un asunto de personas mayores. En este contexto, están suscitando más atención las situaciones que implican más interacciones intergeneracionales. Dentro del campo intergeneracional está aumentando el interés en torno a las posibilidades de expandir el papel de la tecnología en los programas intergeneracionales. En consecuencia, este artículo se centra en los procesos de educación y aprendizaje acaecidos dentro de programas intergeneracionales con un fuerte componente tecnológico. Mediante un sondeo se recogió información sobre un total de 46 de este tipo de programas de 11 países. Todos se han evaluado en la muestra según su nivel de impacto, el estatus de los grupos generacionales y la centralidad de la tecnología. La enseñanza-aprendizaje de la tecnología constituye la principal área de impacto buscada por estos programas, que, no obstante, también utilizan una amplia variedad de estrategias para facilitar la comunicación, la cooperación y la formación de relaciones intergeneracionales entre las generaciones implicadas. El interés de los programas analizados no solo consiste en enseñar a utilizar la tecnología sino en experimentar diferentes formas y funciones con ella, así como en explorar el potencial positivo de la tecnología para mejorar las relaciones intergeneracionales


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Victor Chaban

Clinical studies suggest the comorbidity of functional pain syndromes such as irritable bowel syndrome, painful bladder syndrome, chronic pelvic pain, and somatoform disorders approaches 40% to 60%. The incidence of episodic or persistent visceral pain associated with these “functional” disorders is two to three times higher in women than in men. One of the possible explanations for this phenomenon is estrogen modulation of viscerovisceral cross-sensitization. While a central site of this modulation has been shown previously, our studies suggest a peripheral site, the dorsal root ganglion (DRG). Estrogens have remarkably wide range of functions including modulation of voltage-gated calcium channels (VGCCs) and purinoreceptors (P2Xs). Significantly, inflammation dramatically alters purinoception by causing a several fold increase in ATP-activated current, alters the voltage dependence of P2X receptors, and enhances the expression of P2X receptors increasing neuronal hypersensitivity. Gonadal hormones are thought as indispensable cornerstones of the normal development and function, but it appears that no body region, no neuronal circuit, and virtually no cell is unaffected by them. Thus, increasing awareness toward estrogens appears to be obligatory.


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Heather J Tarbet ◽  
Lee Dolat ◽  
Timothy J Smith ◽  
Brett M Condon ◽  
E Timothy O'Brien ◽  
...  

Intermediate filaments (IF) are a major component of the metazoan cytoskeleton and are essential for normal cell morphology, motility, and signal transduction. Dysregulation of IFs causes a wide range of human diseases, including skin disorders, cardiomyopathies, lipodystrophy, and neuropathy. Despite this pathophysiological significance, how cells regulate IF structure, dynamics, and function remains poorly understood. Here, we show that site-specific modification of the prototypical IF protein vimentin with O-linked β-N-acetylglucosamine (O-GlcNAc) mediates its homotypic protein-protein interactions and is required in human cells for IF morphology and cell migration. In addition, we show that the intracellular pathogen Chlamydia trachomatis, which remodels the host IF cytoskeleton during infection, requires specific vimentin glycosylation sites and O-GlcNAc transferase activity to maintain its replicative niche. Our results provide new insight into the biochemical and cell biological functions of vimentin O-GlcNAcylation, and may have broad implications for our understanding of the regulation of IF proteins in general.


Sign in / Sign up

Export Citation Format

Share Document