scholarly journals Mechanobiology: A New Frontier in Biology

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 570
Author(s):  
Tae-Jin Kim

As we observe an increase in muscle mass by lifting weights or a significant mass loss in musculoskeletal tissues of astronauts returning after a stay in space, we note the manifestation of the mechanism of mechanotransduction that is central to mechanobiology [...]

2021 ◽  
Author(s):  
Theo Jenk ◽  
Daniela Festi ◽  
Margit Schwikowski ◽  
Valter Maggi ◽  
Klaus Oeggl

<p>Dating glaciers is an arduous yet essential task in ice core studies, which becomes even more challenging for the dating of glaciers suffering from mass loss in the accumulation zone as result of climate warming. In this context, we present the dating of a 46 m deep ice core from the Central Italian Alps retrieved in 2016 from the Adamello glacier (Pian di Neve, 3100 m a.s.l.). We will show how the timescale for the core could be obtained by integrating results from the analyses of the radionuclides <sup>210</sup>Pb and <sup>137</sup>Cs with annual layer counting derived from pollen and refractory black carbon concentrations. Our results clearly indicate that the surface of the glacier is older than the drilling date of 2016 by about 20 years and that the 46 m ice core reaches back to around 1944. Despite the severe mass loss affecting this glacier even in the accumulation zone, we show that it is possible to obtain a reliable timescale for such a temperate glacier. These results are very encouraging and open new perspectives on the potential of such glaciers as informative palaeoarchives. We thus consider it important to present our dating approach to a broader audience.</p>


1981 ◽  
Vol 59 ◽  
pp. 345-346
Author(s):  
A. Harpaz ◽  
A. Kovetz

The evolution of a 1.2Mʘ star along the asymptotic branch with continuous mass loss is presented, showing that this mass loss leads to the formation of a PN with a typical central star in its center.A former investigation (Harpaz and Kovetz, 1980) has shown that mechanisms for PN creation based on sudden violent processes are not likely to work in the envelope of a red giant star. On the other hand, significant mass loss from red giants was observed as a general phenomenon.We have followed the evolution of a 1.2Mʘ star along the asymptotic branch, including in the evolutionary calculations a mass loss according to Reimers’ empirical formula. It was found that towards the end of this stage, the mass loss rate was about 2.7xl0-6Mʘ/y, which is consistent with the formation of a typical PN within 30,000 years. When the mass content of the hydrogen rich envelope dropped to 1.5x10-3Mʘ, the star began to contract rapidly, forming a typical central star of 0.6Mʘ


1988 ◽  
Vol 34 (118) ◽  
pp. 283-290 ◽  
Author(s):  
Richard B. Alley

AbstractDepth hoar in polar firn forms when large temperature gradients act on low-density firn, but high-density firn does not develop into depth hoar. Low densities in firn may be depositional (burial of surface hoar or still-air snowfall) or diagenetic (mass loss to the free atmosphere, typically in autumn); however, diagenesis is sufficiently strong to cause significant mass loss only in the top 50–100 mm of firn. Between about 50–100 mm and 2 m depth, grain growth and densification are accelerated strongly by temperature-gradient effects; from 2 to 5 m, temperature gradients have a small but measurable effect on rates of processes in firn, and below 5 m rates essentially have isothermal values.Diagenetic depth-hoar layers typically develop in the autumn, are relatively thick, and have smooth bases. Depositional depth-hoar layers may develop at any season, are relatively thin, and have irregular bases. In low-accumulation regions, visual stratification may preserve only an annual signal, but in high-accumulation regions individual storms or other features may be recognizable.


Author(s):  
David A. Armstrong ◽  
Suichu Luo ◽  
David C. Joy

Radiation damage to organic specimens is the major limiting factor in high resolution electron microscopy studies of biological systems. Electron beam irradiation compromises resolution by altering chemical microstructure, resulting in local mass loss and volume shrinkage in a specimen. All significant mass loss is thought to occur prior to a total incident dose of 50 electrons/ square angstrom If this is the case it is hard to reconcile the observation that images must be recorded at doses of less than 100 el/Å in order to avoid excessive mass loss and shrinkage while microanalytical (EDS and EELS) studies of the same tissue are routinely carried out at doses of 104 - 105el/Å2. Also, since most workers typically use either low dose (for imaging) or high dose (for microapalysis) there are apparently no studies in the literature which attempt to follow the process of radiation damage between these two extremes.We have chosen to investigate mass loss in polymer embedding resins such as are routinely used for TEM imaging as well as for X ray microanalytical applications.


1999 ◽  
Vol 191 ◽  
pp. 181-186 ◽  
Author(s):  
J. Hron ◽  
R. Loidl ◽  
S. Höfner ◽  
U.G. Jørgensen ◽  
B. Aringer ◽  
...  

We present ISO-SWS spectra for several representative AGB carbon stars obtained at several phases of the pulsational cycle. For stars with significant mass loss we correct the spectra for the dust emission by using DUSTY models. We then compare these corrected data to synthetic spectra based on hydrostatic and dynamical model atmospheres. We also discuss the influence of the fundamental model parameters on the resulting synthetic spectra.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Mayank Shekhar ◽  
Anshuman Bhardwaj ◽  
Shaktiman Singh ◽  
Parminder S. Ranhotra ◽  
Amalava Bhattacharyya ◽  
...  

1987 ◽  
Vol 93 ◽  
pp. 377-377
Author(s):  
M. Rozyczka ◽  
A. Schwarzenberg-Czerny

AbstractTwo-dimensional hydrodynamic models of the collision region between the stream and the disk in a cataclysmic binary are presented. The adiabatic collision results in significant mass loss from the system and produces large turbulent regions in outer parts of the disk. Radiative cooling of the collision region leeds to a semi-continuous injection of mass into the disk in the form of dense blobs of gas. In both cases the hot regions obtained as a result of the collision are over 1/6 of the circumference of the disk long and almost 40% of its radius deep, deserving to be renamed ‘hot stripes’.


2020 ◽  
Vol 15 (2) ◽  
pp. 66-72
Author(s):  
Z.A. Kormosh ◽  
T.I. Savchuk ◽  
D.I. Semenishin ◽  
S.V. Suprunovich ◽  
V.V. Kochubei ◽  
...  

Ion associates (IA) of butylrodamine C with triiodide and iod bromide have been synthesized. Their thermal behavior is investigated. Thermolysis synthesized by IA BR+I3¯ passes through a number of intermediate stages, since the C4H9 radical, which is part of the dye, has a significant effect on the process of thermolysis of the ionic associate. IA BR+I3¯ begins to decompose significantly at a temperature higher than 140 єC with an endothermic effect at 240 єC and two small exothermic effects with a maximum at 282 єC and 355 єC (corresponding to the release of 2NH3, 8C2H4, 2HI). In the range of 380–720 єC, the exothermic effect of the IA combustion occurs at a temperature of 485 єC with significant mass loss. The obtained IAs are stable under normal conditions. An I3¯ and I2Br¯ sensor containing butyrodromine C associate of butylrodamine C with triiodide and iodum bromide was developed. The working interval of the pH of the triiodide sensor is 2 - 12, and for iodum bromide, the pH is 2 - 10, respectively. The linearity interval of the electrode function is in the range 9 ∙10-6 - 1 ∙10-1 mol L-1, the slope is 65 mV/pC for the triiodide, and for the iodine bromide - 1 ∙10-5 - 1 ∙10-1 mol L-1, the slope 68 mV/pC. The technique of potentiometric determination of analgin in medicines is developed.


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