scholarly journals 2.5D Tractions in monocytes reveal mesoscale mechanics of podosomes during substrate indenting cell protrusion

2021 ◽  
Author(s):  
Hendrik Schürmann ◽  
Antonella Russo ◽  
Arne D Hofemeier ◽  
Matthias Brandt ◽  
Johannes Roth ◽  
...  
Keyword(s):  
Cancer Metastasis ◽  
Mechanical Forces ◽  
Scale Dependency ◽  
Spatiotemporal Model ◽  
Buckling Instability ◽  
Cell Protrusion ◽  
Out Of Plane ◽  
Leukocyte Extravasation ◽  
Individual Scale ◽  
The Individual

Degradation and protrusion are key to cellular barrier breaching in cancer metastasis and leukocyte extravasation. Cancerous invadopodia and myelomonocytic podosomes are widely considered as structural tools facilitating these processes and are thus summarized under the term invadosomes. Despite similar behaviour on the individual scale, substantial differences have been reported to arise on the collective scale. They are considered to be a result of podosome mesoscale-connectivity. In this study, we investigated global in-plane and out-of-plane mechanical forces of podosome clusters in ER-Hoxb8 cell derived monocytes. We are able to correlate these forces with the interpodosomal connectivity. The observed traction and protrusion patterns fail to be explained by summation of single podosome mechanics. Instead, they appear to originate from superimposed mesoscale effects. Based on mechanistic and morphological similarities with epithelial monolayer mechanics, we propose a spatiotemporal model of podosome cluster mechanics capable of relating single to collective podosome mechanical behaviour. Our results suggest that network contraction-driven (in-plane) tractions lead to a buckling instability that contributes to the out-of-plane indentation into the substrate. First assigning an active mechanical role to the dorsal podosome actomyosin network, we aim at translating actomyosin hierarchy into scale dependency of podosome mechanics.

scholarly journals Orientation-Dependent Reflection of Structurally Coloured Butterflies

Biomimetics ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 5
Author(s):  
Sigrid Zobl ◽  
Bodo D. Wilts ◽  
Willi Salvenmoser ◽  
Peter Pölt ◽  
Ille C. Gebeshuber ◽  
...  
Keyword(s):  
Orientation Dependence ◽  
Butterfly Species ◽  
Butterfly Wing ◽  
Step Size ◽  
Photonic Structures ◽  
Light Interference ◽  
Important Input ◽  
Individual Scale ◽  
The Individual ◽  
Wing Scales

The photonic structures of butterfly wing scales are widely known to cause angle-dependent colours by light interference with nanostructures present in the wing scales. Here, we quantify the relevance of the horizontal alignment of the butterfly wing scales on the wing. The orientation-dependent reflection was measured at four different azimuth angles, with a step size of 90°, for ten samples—two of different areas of the same species—of eight butterfly species of three subfamilies at constant angles of illumination and observation. For the observed species with varying optical structures, the wing typically exhibits higher orientation-dependent reflections than the individual scale. We find that the measured anisotropy is caused by the commonly observed grating structures that can be found on all butterfly wing scales, rather than the local photonic structures. Our results show that the technique employed here can be used to quickly evaluate the orientation-dependence of the reflection and hence provide important input for bio-inspired applications, e.g., to identify whether the respective structure is suitable as a template for nano-imprinting techniques.

Alternative Approaches to Analyzing SWAT Data

1987 ◽  
Vol 31 (1) ◽  
pp. 63-66 ◽  
Author(s):  
David W. Biers ◽  
Philip J. Masline
Keyword(s):  
Rating Scale ◽  
Memory Task ◽  
Task Demands ◽  
Conjoint Measurement ◽  
Multivariate Statistical ◽  
Alternative Approaches ◽  
Highly Correlated ◽  
Using Data ◽  
Individual Scale ◽  
The Individual

The present study sought to determine the sensitivity of three alternative approaches to deriving a workload composite measure based upon data gathered using the Subjective Workload Assessment Technique (SWAT) and to determine through the use of multivariate statistical procedures (MANOVA) if anything is to be gained by retaining the individual scale information of SWAT. The three rating scale dimensions of SWAT (time load, mental effort load, psychological stress load) were combined into a single workload composite using three techniques: conjoint measurement; a simple sum of the three scales weighted equally; an empirically determined weighted-linear combination of the three scales (from MANOVA). Using data gathered by having subjects perform a continuous memory task under twelve levels of task difficulty, it was found that the three composite measures were equally sensitive and highly correlated (the minimum correlation among the three composites being 0.9913). The results of the MANOVA performed on the same data indicated that the individual scales of SWAT were differentially sensitive to different task demands and that individual scale information should be retained rather than rely on a simple composite.

Spectra of the 1:1 and 3:1 solid complexes of coronene-TCNQ

1977 ◽  
Vol 55 (21) ◽  
pp. 3712-3716 ◽  
Author(s):  
Kim Doan Truong ◽  
André D. Bandrauk
Keyword(s):  
Charge Transfer ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Ground State ◽  
Electronic Absorption Spectra ◽  
Charge Transfer Band ◽  
Out Of Plane ◽  
The Individual ◽  
A Charge ◽  
Solid Complexes

Two new solid TCNQ complexes have been isolated, coronene–TCNQ 1:1 and 3:1. The infrared and electronic absorption spectra are presented for the two different stoichiometries. From these spectra we infer that the complexes are covalent in the ground state with a charge transfer band appearing at 730 nm. The out of plane vibrations of the individual molecules are noticeably perturbed upon complexation.

Evaluation of the Accuracy of Out-of-Plane Normal Stress Detection Using Novel Piezoresistive CMOS Sensors

2009 ◽  
Author(s):  
Benjamin Lemke ◽  
Rajashree Baskaran ◽  
Oliver Paul
Keyword(s):  
Normal Stress ◽  
Stress Component ◽  
Stress Detection ◽  
Free Surfaces ◽  
Plane Normal ◽  
Uncertainty Sources ◽  
Stress Components ◽  
Normal Stress Component ◽  
Out Of Plane ◽  
The Individual

This paper discusses the measurement opportunities arising from a novel piezoresistance sensor featuring vertical currents. Temperature-compensated measurements of a sum of the three normal stress components including the vertical normal stress, are presented. In specific applications with sensors located at free surfaces where the vertical normal stress component vanishes, a combination of this temperature-compensated measurement and a pseudo-Hall measurement yields the individual in-plane normal stresses. Furthermore, the temperature-uncompensated extraction of the vertical normal stress component is discussed with respect to the new measurement possibilities provided by the presented sensor. A sensitivity analysis illustrates the influence of individual uncertainty sources to the overall uncertainty of the measurement. Based on these results possible improvements in stress detection are suggested.

scholarly journals Computational Simulations of the Anterior Vertebral Surface for Optimal Surgical Instrumentation Design

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Francisco Casesnoves
Keyword(s):  
Vertebral Body ◽  
Design Method ◽  
Computational Design ◽  
Human Bone ◽  
Mechanical Forces ◽  
Grid Data ◽  
Statistical Parameters ◽  
Surgical Instrumentation ◽  
The Individual ◽  
Fitting Model

The engineering design of surgical instrumentation to apply mechanical forces and linear moments on the human bones during the operations constitutes a rather difficult task. This is due both to the natural and pathological irregularities of the human bone morphology and surfaces and also to the individual variations from one patient to another. Usually, the forces are applied by the surgeon only on a determined part of the bone surfaces. This paper describes an innovative computational design method to digitalize, simulate, and fit mathematically the anterior vertebral body facet. We used real experimental data from 17 human cadaveric specimens to get and store a large amount of numerical surface digital values. The complete anterior vertebral body side was visualized and analyzed with grid data Subroutine, which was also used first to select the so-called natural regions of interest (ROIs). These ROIs correspond to those parts of the surface in contact with the surgical instrumentation, where the mechanical forces are applied. Subsequently, a numerical mathematical fitting-model was implemented for these ROIs. This was carried out with the development of a 3D geometrical least-squares optimization algorithm and appropriate software designed according to the proper numerical method selected. In doing so, the 3D superficies equations of the anterior vertebral body (L3, L4, L5, and S1) were determined after these fittings were mathematically checked as appropriate. Statistical parameters and determination coefficients that define the error boundaries and the goodness of this optimal fitting-model were calculated and NURBS error data in similar studies were commented. It was proven that the principal source of error was the micro- and macro-irregularities of human bone facets. The final surface equations, and their geodesics, were used to obtain accurate data for the spinal surgery instrumentation manufacturing. The industrial bioengineering result was the application of these equations for the design of a new spinal vertebral surgical distractor. This innovative distractor separates two adjacent vertebrae while keeping them parallel. That is, at their natural inclination, avoiding hammering the vertebrae to make the intervertebral space wider. The device mechanics also minimizes the necessary force to be carried out by the surgeon during the operation.

Reflexion of light by external surfaces of the herring, Clupea harengus

1965 ◽  
Vol 45 (3) ◽  
pp. 711-738 ◽  
Author(s):  
E. J. Denton ◽  
J. A. C. Nicol
Keyword(s):  
Green Light ◽  
Normal Incidence ◽  
Clupea Harengus ◽  
Sea Surface ◽  
Histological Studies ◽  
Fresh Fish ◽  
Wide Range ◽  
Individual Scale ◽  
The Individual

The orientations of the reflecting layers in the external surfaces of the herring have been found both by light-measurements on the fresh fish and by histological studies on preserved specimens.The reflecting platelets which lie under the scales are orientated, with respect to the surface of the fish, in a similar way to the platelets found in the bleak and described earlier by Demon & Nicol (1965). However, on the curved dorsum of the fish, although the reflecting platelets are much more perpendicular to the sea surface than the scales on which they lie, these platelets are still inclined some 20° to the perpendicular. It is shown that, in this region, the fish reflects the fraction of the light striking the platelets which is sufficient to match the background against which the fish is seen. The platelets on the curved dorsum have the property of reflecting green light well if it falls obliquely on them but reflecting it poorly when it strikes them at angles close to normal incidence. On the broad flank of the herring the scales have reflecting platelets under most of their surfaces, and the individual scale has several distinctly coloured regions. When we look at any particular region of the flank of an intact fish we are always looking at several overlapping layers differing greatly from one another in their spectral reflecting properties.It is the combination of the reflexions of several layers which gives the very bright silvery reflexions of the intact fish. A system of overlapping scales of this kind is needed even to reflect one waveband of light well over a wide range of angles of incidence.

Proton and fluorine magnetic resonance studies of some benzoyl fluoride derivatives. Sensitivity of the fluorine shifts to intramolecular van der Waals interactions and steric effects

1977 ◽  
Vol 55 (22) ◽  
pp. 3936-3941 ◽  
Author(s):  
Ted Schaefer ◽  
Kirk Marat ◽  
Kalvin Chum ◽  
Alexander F. Janzen
Keyword(s):  
Magnetic Resonance ◽  
Van Der Waals ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Van Der Waals Interactions ◽  
Proton Proton ◽  
Out Of Plane ◽  
Spin Coupling Constants ◽  
The Individual ◽  
Spin Spin Coupling

The syntheses and the analyses of the high resolution proton and fluorine magnetic resonance spectra of the 3-fluoro-4-methyl-, 2-fluoro-5-chloro-, 2-fluoro-6-chloro-, 2,6-difluoro-, and of the pentafluorobenzoyl fluorides are reported. The spin–spin coupling constants over five bonds between the sidechain fluorine-19 and the ring protons are sensitive to intrinsic substituent perturbations. Their use in the deduction of conformational preferences is much more problematical than is the use of the corresponding proton–proton couplings in benzaldehyde derivatives. The 2-fluoro-6-chloro compound is nonplanar, as indicated by a finite magnitude of the long-range proton–fluorine coupling over six bonds. The nonplanarity is also indicated by a comparison of the through-space fluorine–fluorine coupling to those in the other compounds. The chemical shift of the sidechain fluorine moves to low field by over 35 ppm as the size of the two ortho substituents increases. The individual shifts are discussed in terms of intramolecular van der Waals interactions and of out-of-plane twisting of the COF group.

scholarly journals Individual-scale inference to anticipate climate-change vulnerability of biodiversity

2012 ◽  
Vol 367 (1586) ◽  
pp. 236-246 ◽  
Author(s):  
James S. Clark ◽  
David M. Bell ◽  
Matthew Kwit ◽  
Anne Stine ◽  
Ben Vierra ◽  
...  
Keyword(s):  
Climate Change ◽  
Individual Tree ◽  
Demographic Rates ◽  
Competitive Environments ◽  
Scale Models ◽  
Competition For Light ◽  
Input Variables ◽  
Individual Scale ◽  
The Individual ◽  
Demographic Responses

Anticipating how biodiversity will respond to climate change is challenged by the fact that climate variables affect individuals in competition with others, but interest lies at the scale of species and landscapes. By omitting the individual scale, models cannot accommodate the processes that determine future biodiversity. We demonstrate how individual-scale inference can be applied to the problem of anticipating vulnerability of species to climate. The approach places climate vulnerability in the context of competition for light and soil moisture. Sensitivities to climate and competition interactions aggregated from the individual tree scale provide estimates of which species are vulnerable to which variables in different habitats. Vulnerability is explored in terms of specific demographic responses (growth, fecundity and survival) and in terms of the synthetic response (the combination of demographic rates), termed climate tracking. These indices quantify risks for individuals in the context of their competitive environments. However, by aggregating in specific ways (over individuals, years, and other input variables), we provide ways to summarize and rank species in terms of their risks from climate change.

Design and Analysis of Actuated Microneedles for Robotic Manipulation

2014 ◽  
Author(s):  
Steven Banerjee ◽  
Wenhui Wang ◽  
Stefanie Gutschmidt
Keyword(s):  
Single Unit ◽  
Analytical Modeling ◽  
Parallel Architecture ◽  
Robotic Manipulation ◽  
Element Analysis ◽  
Out Of Plane ◽  
Fea Simulation ◽  
Multiple Actuators ◽  
The Individual ◽  
Operational Range

We present the design of a MEMS based single-unit actuator consisting of a single microneedle with 3D mobility. The four-sided single-unit actuator (4SA) microrobot design can achieve an in-plane actuation (x, y) of 76 μm (±38 μm) at 160 V and an out-of-plane actuation (z) of more than 6.5 μm at 35 V. The mechanical stress developed within the operational range is between 0.08 to 0.5 percent of the yield strength of silicon i.e. 7000 MPa. We discuss both the analytical modeling and finite element analysis (FEA) simulation of the design based on the range of dimensions analyzed for the individual actuator components. Our primary goal is to integrate multiple actuators into a parallel architecture for independent actuation of multiple microneedles for targeted micro- and nano-robotic manipulation tasks, such as single-cell analyses. We have also successfully fabricated sample 4SA microrobot without the microneedle as a pre-cursor to experimenting with our future advanced design of microrobots. We demonstrate successfully the 3D actuation of the 4SA microrobot of up to 10 μm at 120 V (in-plane) and more than 0.5 μm at 600 V (out-of-plane) with minimum decoupling.

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