scholarly journals Reorganisation of complex ciliary flows around regenerating Stentor coeruleus

2019 ◽  
Author(s):  
Kirsty Y. Wan ◽  
Sylvia K. Hürlimann ◽  
Aidan M. Fenix ◽  
Rebecca M. McGillivary ◽  
Tatyana Makushok ◽  
...  
Keyword(s):  
Anterior Part ◽  
Single Cells ◽  
Ring Structure ◽  
The Body ◽  
Band Formation ◽  
Environmental Perturbations ◽  
Biophysical Studies ◽  
Stentor Coeruleus ◽  
And Migration ◽  
Anterior Ring

SummaryThe phenomenon of ciliary coordination has garnered increasing attention in recent decades, with multiple theories accounting for its emergence in different contexts. The heterotrich ciliate Stentor coeruleus is a unicellular organism which boasts a number of features which present unrivalled opportunities for biophysical studies of cilia coordination. With their cerulean colour and distinctive morphology, these large protists possess a characteristic differentiation between cortical rows of short body cilia used for swimming, and an anterior ring structure of fused oral cilia forming a membranellar band. The oral cilia beat metachronously to produce strong feeding currents. In addition to this complex body plan, Stentor have remarkable regenerative capabilities. Minute fragments of single cells can over the period of hours or days, regenerate independently into new, proportional individuals. Certain environmental perturbations elicit a unique programmed response known as oral regeneration wherein only the membranellar band is shed and a new, ciliated oral primordium formed on the side of the body. Here, we target oral regeneration induced by sucrose-shock to reveal the complex interplay between ciliary restructuring and hydrodynamics in Stentor, which accompanies the complete developmental sequence from band formation, elongation, curling, and migration toward the cell anterior.“When the anterior part is open, one may perceive about its Edges a very lively Motion; and when the Polyps presents itself in a certain manner, it discovers, on either side of these edges of its anterior part, somewhat very much resembling the wheels of a little Mill, that move with great velocity.”A. Trembley F.R.S describing the membranellar band of Stentor, Phil. Soc. Trans. Royal Society (London), 1744.

scholarly journals Reorganization of complex ciliary flows around regenerating Stentor coeruleus

2019 ◽  
Vol 375 (1792) ◽  
pp. 20190167 ◽  
Author(s):  
Kirsty Y. Wan ◽  
Sylvia K. Hürlimann ◽  
Aidan M. Fenix ◽  
Rebecca M. McGillivary ◽  
Tatyana Makushok ◽  
...  
Keyword(s):  
Large Scale ◽  
Fluid Transport ◽  
De Novo ◽  
Band Formation ◽  
Large Size ◽  
Cellular Regeneration ◽  
Stentor Coeruleus ◽  
Anterior Ring ◽  
First Time ◽  
Short Body

The phenomenon of ciliary coordination has garnered increasing attention in recent decades and multiple theories have been proposed to explain its occurrence in different biological systems. While hydrodynamic interactions are thought to dictate the large-scale coordinated activity of epithelial cilia for fluid transport, it is rather basal coupling that accounts for synchronous swimming gaits in model microeukaryotes such as Chlamydomonas. Unicellular ciliates present a fascinating yet understudied context in which coordination is found to persist in ciliary arrays positioned across millimetre scales on the same cell. Here, we focus on the ciliate Stentor coeruleus , chosen for its large size, complex ciliary organization, and capacity for cellular regeneration. These large protists exhibit ciliary differentiation between cortical rows of short body cilia used for swimming, and an anterior ring of longer, fused cilia called the membranellar band (MB). The oral cilia in the MB beat metachronously to produce strong feeding currents. Remarkably, upon injury, the MB can be shed and regenerated de novo. Here, we follow and track this developmental sequence in its entirety to elucidate the emergence of coordinated ciliary beating: from band formation, elongation, curling and final migration towards the cell anterior. We reveal a complex interplay between hydrodynamics and ciliary restructuring in Stentor , and highlight for the first time the importance of a ring-like topology for achieving long-range metachronism in ciliated structures. This article is part of the Theo Murphy meeting issue ‘Unity and diversity of cilia in locomotion and transport’.

scholarly journals Extracellular-Vesicle-Based Coatings Enhance Bioactivity of Titanium Implants—SurfEV

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1445
Author(s):  
Taisa Nogueira Pansani ◽  
Thanh Huyen Phan ◽  
Qingyu Lei ◽  
Alexey Kondyurin ◽  
Bill Kalionis ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Titanium Surface ◽  
Wound Closure ◽  
Cell Types ◽  
Extracellular Vesicle ◽  
Tissue Growth ◽  
Titanium Implants ◽  
The Body ◽  
High Concentrations ◽  
And Migration

Extracellular vesicles (EVs) are nanoparticles released by cells that contain a multitude of biomolecules, which act synergistically to signal multiple cell types. EVs are ideal candidates for promoting tissue growth and regeneration. The tissue regenerative potential of EVs raises the tantalizing possibility that immobilizing EVs on implant surfaces could potentially generate highly bioactive and cell-instructive surfaces that would enhance implant integration into the body. Such surfaces could address a critical limitation of current implants, which do not promote bone tissue formation or bond bone. Here, we developed bioactive titanium surface coatings (SurfEV) using two types of EVs: secreted by decidual mesenchymal stem cells (DEVs) and isolated from fermented papaya fluid (PEVs). For each EV type, we determined the size, morphology, and molecular composition. High concentrations of DEVs enhanced cell proliferation, wound closure, and migration distance of osteoblasts. In contrast, the cell proliferation and wound closure decreased with increasing concentration of PEVs. DEVs enhanced Ca/P deposition on the titanium surface, which suggests improvement in bone bonding ability of the implant (i.e., osteointegration). EVs also increased production of Ca and P by osteoblasts and promoted the deposition of mineral phase, which suggests EVs play key roles in cell mineralization. We also found that DEVs stimulated the secretion of secondary EVs observed by the presence of protruding structures on the cell membrane. We concluded that, by functionalizing implant surfaces with specialized EVs, we will be able to enhance implant osteointegration by improving hydroxyapatite formation directly at the surface and potentially circumvent aseptic loosening of implants.

scholarly journals Cell migration guided by long-lived spatial memory

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joseph d’Alessandro ◽  
Alex Barbier--Chebbah ◽  
Victor Cellerin ◽  
Olivier Benichou ◽  
René Marc Mège ◽  
...  
Keyword(s):  
Cell Migration ◽  
Spatial Memory ◽  
Large Scale ◽  
Single Cells ◽  
Environmental Perturbations ◽  
Motile Cells ◽  
Unicellular Organisms ◽  
Biochemical Signals ◽  
The Impact ◽  
Cell Trajectories

AbstractLiving cells actively migrate in their environment to perform key biological functions—from unicellular organisms looking for food to single cells such as fibroblasts, leukocytes or cancer cells that can shape, patrol or invade tissues. Cell migration results from complex intracellular processes that enable cell self-propulsion, and has been shown to also integrate various chemical or physical extracellular signals. While it is established that cells can modify their environment by depositing biochemical signals or mechanically remodelling the extracellular matrix, the impact of such self-induced environmental perturbations on cell trajectories at various scales remains unexplored. Here, we show that cells can retrieve their path: by confining motile cells on 1D and 2D micropatterned surfaces, we demonstrate that they leave long-lived physicochemical footprints along their way, which determine their future path. On this basis, we argue that cell trajectories belong to the general class of self-interacting random walks, and show that self-interactions can rule large scale exploration by inducing long-lived ageing, subdiffusion and anomalous first-passage statistics. Altogether, our joint experimental and theoretical approach points to a generic coupling between motile cells and their environment, which endows cells with a spatial memory of their path and can dramatically change their space exploration.

scholarly journals PLCε1 regulates SDF-1α–induced lymphocyte adhesion and migration to sites of inflammation

2017 ◽  
Vol 114 (10) ◽  
pp. 2693-2698 ◽  
Author(s):  
Marianne Strazza ◽  
Inbar Azoulay-Alfaguter ◽  
Michael Peled ◽  
Alan V. Smrcka ◽  
Edward Y. Skolnik ◽  
...  
Keyword(s):  
T Cell ◽  
Small Gtpase ◽  
The Body ◽  
Delayed Type Hypersensitivity ◽  
Intercellular Adhesion Molecule ◽  
Intercellular Adhesion Molecule 1 ◽  
Regional Lymph Nodes ◽  
Lymphocyte Adhesion ◽  
Enzymatic Function ◽  
And Migration

Regulation of integrins is critical for lymphocyte adhesion to endothelium and migration throughout the body. Inside-out signaling to integrins is mediated by the small GTPase Ras-proximate-1 (Rap1). Using an RNA-mediated interference screen, we identified phospholipase Cε 1 (PLCε1) as a crucial regulator of stromal cell-derived factor 1 alpha (SDF-1α)-induced Rap1 activation. We have shown that SDF-1α-induced activation of Rap1 is transient in comparison with the sustained level following cross-linking of the antigen receptor. We identified that PLCε1 was necessary for SDF-1α-induced adhesion using shear stress, cell morphology alterations, and crawling on intercellular adhesion molecule 1 (ICAM-1)–expressing cells. Structure–function experiments to separate the dual-enzymatic function of PLCε1 uncover necessary contributions of the CDC25, Pleckstrin homology, and Ras-associating domains, but not phospholipase activity, to this pathway. In the mouse model of delayed type hypersensitivity, we have shown an essential role for PLCε1 in T-cell migration to inflamed skin, but not for cytokine secretion and proliferation in regional lymph nodes. Our results reveal a signaling pathway where SDF-1α induces T-cell adhesion through activation of PLCε1, suggesting that PLCε1 is a specific potential target in treating conditions involving migration of T cells to inflamed organs.

Messing up the Domestic: Queer Bodies Expanding Architectures

Somatechnics ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 397-415
Author(s):  
Olivier Vallerand
Keyword(s):  
Online Social Networks ◽  
Architectural Design ◽  
The Body ◽  
Domestic Spaces ◽  
Queer Space ◽  
Political Relations ◽  
Digital Environments ◽  
Lgbt People ◽  
And Migration ◽  
Architecture And Design

Queer space discourse in architecture has often been about reclaiming sexualized spaces or spaces used by LGBT people as being part of architectural history. However, critical practitioners have sought to expand from an understanding based on an essentialist understanding of queer bodies to link instead the experience of built environments to the repression of non-normative/non-compliant bodies. This article discusses projects by J. Mayer H., Andrés Jaque/Office for Political Innovation (OFFPOLINN), and MYCKET that build on a queer understanding of architecture and design to explore relationships between bodies, the materiality of domestic spaces, and communal identities, challenging binary understandings of architectural design spaces and linking them to the configuration of citizenship. J. Mayer H.’s work on data-protection patterns and thermo-sensitive materials uses bodies as material in developing a discourse on privacy stemming in part from queer people's experience of oppressing policies. OFFPOLINN's projects on IKEA and on gay cruising digital environments question the role of architects by underlining the close integration of advertisement, online social networks, and urban and architectural policies in relation to the experience of citizenship and migration. Finally, MYCKET's queer feminist performative architectures attempts to reframe the neutrality of the architectural modernist tradition to celebrate the messiness that comes with thinking of space as designed for a diversity of people. The three practices expand architectural discussions of domesticity beyond an understanding of the house as a container for family life and towards seeing it as a nexus of social and political relations that converge around the body.

Gender differences and the role of parental education, school types and migration on the body mass index of 2930 Austrian school children

2017 ◽  
Vol 129 (21-22) ◽  
pp. 786-792 ◽  
Author(s):  
Dieter Furthner ◽  
Margit Ehrenmüller ◽  
Ariane Biebl ◽  
Roland Lanzersdorfer ◽  
Gerhard Halmerbauer ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Gender Differences ◽  
Body Mass ◽  
School Children ◽  
Parental Education ◽  
The Body ◽  
Austrian School ◽  
Education School ◽  
And Migration

A systematic review of Karen refugee health

2016 ◽  
Vol 12 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Sarah J. Hoffman ◽  
Cheryl L. Robertson
Keyword(s):  
Mental Health ◽  
Forced Migration ◽  
The Body ◽  
Health Needs ◽  
Health Providers ◽  
Physical And Mental Health ◽  
Content Type ◽  
And Migration ◽  
Karen Refugees ◽  
The Impact

Purpose – The purpose of this paper is to provide a comprehensive perspective of the documented physical and mental health issues Karen refugees from Burma face as a result of war and refugee trauma, and migration. The review will address the question: What is the impact of trauma and migration on the physical and mental health of Karen refugees? Design/methodology/approach – A total of 18 articles were systematically selected for inclusion in the final review. The focal content for included articles includes qualitative and quantitative research representative of the health and migration experiences of Karen refugees. Findings – The findings of this review demonstrate significance for health providers from a public health standpoint as programs and services are targeted to meet the specific health needs of the Karen community. It also highlights the contribution of the Karen forced migration experience to the complexity of individual and community health needs, particularly as a result of the protracted conflict. Originality/value – This critical appraisal of the body of literature describing the health experiences of Karen refugees from Burma, with a particular focus on outcomes relevant to resettlement, demonstrates value as programs are developed with an integrated refugee perspective.

Morphological variations of striped seabream, Lithognathus mormyrus, populations along the Tunisian coast

2011 ◽  
Vol 91 (6) ◽  
pp. 1261-1271 ◽  
Author(s):  
Ibtissem Hammami ◽  
Lilia Bahri-Sfar ◽  
Oum Kalthoum Ben Hassine
Keyword(s):  
Function Analysis ◽  
Anterior Part ◽  
Significant Degree ◽  
The Body ◽  
Statistical Analyses ◽  
Ecological Niches ◽  
Meristic Characters ◽  
Morphometric Variation ◽  
Morphological Variations ◽  
Lithognathus Mormyrus

Morphological variations of Tunisian Lithognathus mormyrus populations were investigated using 41 morphometric measurements (27 truss elements and 14 traditional measurements) and eight meristic characters collected from ten marine and lagoon samples. Statistical analyses (e.g. discriminant function analysis (DFA)) performed separately to truss and traditional data revealed a significant degree of morphological dissimilarity of lagoon samples (Bizerta, Ghar El Melh and El Biban lagoons). For these three lagoon environments the overall assignment of individuals into their original sample (percentage classification success) by DFA was 94% for truss elements and 98% for traditional measurements. This morphological discrimination among lagoon samples, revealed with traditional measurements, seems to be associated only with the anterior part of the body (especially with the pre-orbit and snout length). However, for truss analyses, it was explained by both anterior and posterior parts (peduncle region). Statistical analyses for only marine samples showed partial overlapping with significant morphometric variation of the Chebba and Gabès samples mainly related to the anterior part of the body, for the first sample, but also to the posterior region, for the second one. These morphometric variations are often due to environmental conditions and mainly to the exploitation of different ecological niches that are particularly limited by the availability, type and size of prey. Thus, truss and traditional approaches are complementary and provide more accurate explanations of such a morphological discrimination. Meristic character analyses showed homogeneity of striped seabream samples, except for the Ghar El Melh lagoon sample which quietly differed from the others. This distinction was mainly explained by the number of soft anal rays.

scholarly journals Visualizing Simultaneity in Diasporic Public Spheres: The case of the Mexican Diaspora in the U.S.

JOMEC Journal ◽  
2017 ◽  
pp. 23
Author(s):  
Gabriel Moreno Esparza ◽  
Rosa Angélica Martínez Téllez
Keyword(s):  
Political Participation ◽  
News Media ◽  
The Body ◽  
The Political ◽  
Public Spheres ◽  
Interactive Spaces ◽  
Digital News ◽  
And Migration ◽  
The U.S

This article argues that explorations of interactive spaces afforded by digital news media provide a dynamic platform to visualize the prospects for the political participation of diasporas in their countries of origin and residence. In this case, a breakdown of the frequency of comments across a variety of news sections about Mexico and the U.S. in Univision.com uncovered a lively range of interactions between news forum participants, signalling simultaneous interest in on-going events and processes in the two countries. The dual national orientations highlighted by these findings ‘touch base’ with the body of literature about media and migration, which has in recent times recognised the interconnectedness of immigrants-sending and receiving societies, whilst offering a more refined conceptualization of the concept of simultaneity in regard to diasporic public spheres.

scholarly journals Surgical Hemostasis for Severe Multisystem Pelvic Injuries

2020 ◽  
Vol 8 (4) ◽  
pp. 396-408
Author(s):  
I. V. Kazhanov ◽  
A. Y. Demko ◽  
V. A. Manukovsky ◽  
S. I. Mikityuk ◽  
V. A. Reva ◽  
...  
Keyword(s):  
Pelvic Ring ◽  
Anterior Part ◽  
Treatment Algorithm ◽  
Pelvic Trauma ◽  
Balloon Occlusion ◽  
The Body ◽  
Military Surgery ◽  
Transfusion Therapy ◽  
Homogeneous Groups ◽  
Military Medical Academy

For the treatment of patients with severe multysistem pelvic trauma accompanied by pelvic bleeding, many algorithms have been proposed that have different procedures for the use of various methods of surgical hemostasis, but none of them may guarantee the complete arrest of pelvic bleeding. The purpose of this study was to estimate clinical efficacy and developed algorithm, aimed at timely diagnosis of intrapelvic bleeding and its complete arrest with the help of different methods of surgical hemostasis in patients with severe concomitant injury of the pelvis. The article analyzes the results of treatment of 168 patients with unstable pelvic ring injuries and signs of intrapelvic bleeding, who were treated in two trauma centers of the first level in St. Petersburg: I.I. Dzhanelidze St. Petersburg Research Institute of Emergency Medicine and Military Surgery Clinic of S.M. Kirov Military Medical Academy in 2010-2018. The victims were divided into two statistically homogeneous groups. In the comparison group (75 people), the pelvic ring was mechanically stabilized with the Ganz C-clamp or the anterior part of the pelvis was fixed with an external fixation device (EFD), and the arrest of the ongoing pelvic bleeding was expected due to occur due to the effect of biological tamponade. In the main group (93 people), after mechanical stabilization of the pelvic ring, various methods of surgical hemostasis were used: balloon occlusion of the aorta, pelvic tamponade, angiography with embolization. The choice of method for surgical haemostasis after trauma depended on the severity of the affected condition of hemodynamic parameters, availability of life-threatening consequences of damage to other areas of the body and the efficacy of previously applied method for intrapelvic bleeding arrest. The introduction of modern diagnostic and treatment algorithm, aimed at complete hemostasis in patients with ongoing intrapelvic bleeding reduced the overall mortality rate by 1.7 times, mortality within 24 hours of admission by 2.3 times, as well as the duration and the volume of blood transfusion therapy by 3 and 1.8 times.Authors declare lack of the conflicts of interests.

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