MODELING AND SIMULATION OF MECHANICAL PROPERTIES OF PULVERIZED COW BONE AND LATERITIC PAVING TILES

This study included the experimental production and investigation of the mechanicalproperties of paving tiles produced from a mixture of laterite, silica sand, pulverized cow bones,and cement. Empirical models of compressive and flexural strength were also developed andherein presented for the paving tiles. The maximum compressive strength of the paving tiles wereobtained for 20, 15, and 10% cement content as 5.05, 5.05 and 3.08 MPa, while the maximumflexural strength for similar values of cement content were obtained as 1.83, 1.21 and 0.26 MParespectively. The results indicate that there was no noticeable difference in the values of thecompressive strength at 20 and 15% cement content, while a sharp reduction of the mechanicalproperties was experienced as the cement content reduces from 15 to 10%. Recommendedcomposition for paving tiles with pulverized cow bones composite is cement, 15%; pulverized cowbones, 30%; laterite 35% and silica sand, 20% respectively. Sustainable production of paving tilesand a sustainable environment can, therefore, be enhanced by replacing granite constituent withwaste cow bones, which can easily be replicated by the empirical models herein developed

A new isoflavone from stem bark of Millettia dura

A new isoflavone (7,3’-dimethoxy-4’,5’-methylenedioxyisoflavone) and three known isoflavones [isoerythrinin A 4’-(3-methylbut-2-enyl) ether, isojamaicin and nordurlettone] were isolated from the stem bark of Millettia dura (Leguminosae). The structures were determined by spectroscopic methods. KEY WORDS: Millettia dura, Leguminosae, Isoflavone, 7,3’-Dimethoxy-4’,5’-methylenedioxyisoflavone, Isoerythrinin A 4’-(3-methylbut-2-enyl) ether, Isojamaicin,Nordurlettone_Bull. Chem. Soc. Ethiop. 2003, 17(1), 113-115

The endothelial glycocalyx prefers albumin for evoking shear stress-induced, nitric oxide-mediated coronary dilatation

Background: Shear stress induces coronary dilatation via production of nitric oxide ( NO). This should involve the endothelial glycocalyx ( EG). A greater effect was expected of albumin versus hydroxyethyl starch ( HES) perfusion, because albumin seals coronary leaks more effectively than HES in an EG-dependent way. Methods: Isolated hearts ( guinea pigs) were perfused at constant pressure with Krebs-Henseleit buffer augmented with 1/3 volume 5% human albumin or 6% HES ( 200/0.5 or 450/0.7). Coronary flow was also determined after EG digestion ( heparinase) and with nitro-L-arginine ( NO-L-Ag). Results: Coronary flow ( 9.50 +/- 1.09, 5.10 +/- 0.49, 4.87 +/- 1.19 and 4.15 +/- 0.09 ml/ min/ g for `albumin', `HES 200', `HES 450' and `control', respectively, n = 5-6) did not correlate with perfusate viscosity ( 0.83, 1.02, 1.24 and 0.77 cP, respectively). NO-L-Ag and heparinase diminished dilatation by albumin, but not additively. Alone NO-L-Ag suppressed coronary flow during infusion of HES 450. Electron microscopy revealed a coronary EG of 300 nm, reduced to 20 nm after heparinase. Cultured endothelial cells possessed an EG of 20 nm to begin with. Conclusions: Albumin induces greater endothelial shear stress than HES, despite lower viscosity, provided the EG contains negative groups. HES 450 causes some NO-mediated dilatation via even a rudimentary EG. Cultured endothelial cells express only a rudimentary glycocalyx, limiting their usefulness as a model system. Copyright (c) 2007 S. Karger AG, Basel

Light regulates alternative splicing outcomes via the TOR kinase pathway

For plants, light is the source of energy and the most relevant regulator of growth and adaptations to the environment by inducing changes in gene expression at various levels, including alternative splicing. Light-triggered chloroplast retrograde signals control alternative splicing in Arabidopsis thaliana. Here, we provide evidence that light regulates the expression of a core set of splicing-related factors in roots. Alternative splicing responses in roots are not directly caused by light but are instead most likely triggered by photosynthesized sugars. The target of rapamycin (TOR) kinase plays a key role in this shoot-to-root signaling pathway. Knocking down TOR expression or pharmacologically inhibiting TOR activity disrupts the alternative splicing responses to light and exogenous sugars in roots. Consistently, splicing decisions are modulated by mitochondrial activity in roots. In conclusion, by activating the TOR pathway, sugars act as mobile signals to coordinate alternative splicing responses to light throughout the whole plant.Fil: Riegler, Stefan. Universitat Fur Bodenkultur Wien; AustriaFil: Servi, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Scarpin, Maria Regina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of California; Estados UnidosFil: Godoy Herz, Micaela Amalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Kubaczka Zoppi, María Guillermina Jazmín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Venhuizen, Peter. Universitat Fur Bodenkultur Wien; AustriaFil: Meyer, Christian. Universite Paris-Saclay; FranciaFil: Brunkard, Jacob O.. University of California; Estados UnidosFil: Kalyna, Maria. Universitat Fur Bodenkultur Wien; AustriaFil: Barta, Andrea. Medizinische Universitat Wien; AustriaFil: Petrillo, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

Ground-state properties of rutile: electron-correlation effects

Electron-correlation effects on cohesive energy, lattice constant and bulk compressibility of rutile are calculated using an ab-initio scheme. A competition between the two groups of partially covalent Ti-O bonds is the reason that the correlation energy does not change linearly with deviations from the equilibrium geometry, but is dominated by quadratic terms instead. As a consequence, the Hartree-Fock lattice constants are close to the experimental ones, while the compressibility is strongly renormalized by electronic correlations.Comment: 1 figure to appear in Phys. Rev.

The Ultimate Fate of Supercooled Liquids

In recent years it has become widely accepted that a dynamical length scale {\xi}_{\alpha} plays an important role in supercooled liquids near the glass transition. We examine the implications of the interplay between the growing {\xi}_{\alpha} and the size of the crystal nucleus, {\xi}_M, which shrinks on cooling. We argue that at low temperatures where {\xi}_{\alpha} > {\xi}_M a new crystallization mechanism emerges enabling rapid development of a large scale web of sparsely connected crystallinity. Though we predict this web percolates the system at too low a temperature to be easily seen in the laboratory, there are noticeable residual effects near the glass transition that can account for several previously observed unexplained phenomena of deeply supercooled liquids including Fischer clusters, and anomalous crystal growth near T_g

Moderate to vigorous physical activity and sedentary behavior changes in self-isolating adults during the COVID-19 pandemic in Brazil: a cross-sectional survey exploring correlates.

BACKGROUND: The COVID-19 pandemic imposed major changes on daily-life routine worldwide. To the best of our knowledge, no study quantified the changes on moderate to vigorous physical activity (MVPA) and sedentary behaviors (SB) and its correlates in Brazilians. This study aimed to (i) evaluate the changes (pre versus during pandemic) in time spent in MVPA and SB in self-isolating Brazilians during the COVID-19 pandemic, and (ii) to explore correlates. METHODS: A cross-sectional, retrospective, self-report online web survey, evaluating the time spent in MVPA and SB pre and during the COVID-19 pandemic in self-isolating people in Brazil. Sociodemographic, behavioral, and clinical measures, and time in self-isolation were also obtained. Changes in MVPA and SB and their correlates were explored using generalized estimating equations (GEE). Models were adjusted for covariates. RESULTS: A total of 877 participants (72.7% women, 53.7% young adults [18-34 years]) were included. Overall, participants reported a 59.7% reduction (95% CI 35.6-82.2) in time spent on MVPA during the pandemic, equivalent to 64.28 (95% CI 36.06-83.33) minutes per day. Time spent in SB increased 42.0% (95% CI 31.7-52.5), corresponding to an increase of 152.3 (95% CI 111.9-192.7) minutes per day. Greater reductions in MVPA and increases in SB were seen in younger adults, those not married, those employed, and those with a self-reported previous diagnosis of a mental disorder. CONCLUSIONS: People in self-isolation significantly reduced MVPA levels and increased SB. Public health strategies are needed to mitigate the impact of self-isolation on MVPA and SB. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11332-021-00788-x