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Signal recognition particle binds to translating ribosomes before emergence of a signal anchor sequence.
The bacterial signal recognition particle (SRP) is part of the machinery that targets ribosomes synthesizing membrane proteins to membrane-embedded translocons co-translationally. Recognition of nascent membrane proteins occurs by virtue of a hydrophobic signal-anchor sequence (SAS) contained in the nascent chain, usually at the N terminus. Here we use fluorescence-based stopped-flow to monitor SRP-ribosome interactions with actively translating ribosomes while an SRP substrate is synthesized and emerges from the peptide exit tunnel. The kinetic analysis reveals that, at cellular concentrations of ribosomes and SRP, SRP rapidly binds to translating ribosomes prior to the emergence of an SAS and forms an initial complex that rapidly rearranges to a more stable engaged complex. When the growing peptide reaches a length of âŒ50 amino acids and the SAS is partially exposed, SRP undergoes another conformational change which further stabilizes the complex and initiates targeting of the translating ribosome to the translocon. These results provide a reconciled view on the timing of high-affinity targeting complex formation, while emphasizing the existence of preceding SRP recruitment steps under conditions of ongoing translation
What\u27s the Beef with Veg*ns: A Mixed Method Approach To Anti-Veg*n Stigma
Despite veg*n scholarship within psychological science, much of this research examined anti-veg*n attitudes amongst non-veg*ns complemented with scarce research on the impact of anti-veg*n stigma and experiences of veg*ns. Underpinned by critical feminist framework with a phenomenological approach, the present study, a convergent mixed method design, examined the relationship between anti-veg*n stigma and multicultural awareness among 165 non-veg*ns and explored the experiences of 13 veg*ns in the context of stigma. Path analysis revealed that multicultural awareness and attitudes towards those with different dietary habits (e.g., veg*n diets, p. 19) was negatively associated with attitudes towards vegans. Additionally, path analysis revealed that attitudes towards vegetarians were negatively associated with attitudes towards different dietary habits and not with multicultural awareness and attitudes. Qualitative analysis revealed 5 salient themes: 1) The Veg*n Experience, 2) Contextual Concealment and Outness, 3) Anti-Veg*n Messages and Discrimination, 4) Navigation Strategies, and 5) Centrality of Nonhuman Consumption and Related-Inequalities. These themes characterized participantsâ experience, perceptions, and navigation of anti-veg*n stigma at all levels of society as well as perceived benefits and costs related to veg*n identification. Integration of qualitative and quantitative revealed differences in perceptions of anti-veg*n attitudes towards veg*ns. Implications for clinical practice, training, and policy development are discussed
Alien Registration- Mercier, Emma M. (Madison, Somerset County)
https://digitalmaine.com/alien_docs/7099/thumbnail.jp
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Binary-mixture droplet evaporation: Lubrication approximation and coffee ring formation
This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.In this paper the dynamics of an evaporating sessile droplet spreading on a horizontal substrate is reported. A mathematical model based on the lubrication approximation is developed accounting for Marangoni effect, contact line motion, and multi-component fluid. After validating the model through pure liquid spreading and evaporation, an extension of the model is performed on a binary component liquid in which composition changes occur during the drying process. Furthermore, the presence of particles in the fluid enables to retrieve the coffee-ring formation. A good qualitative and quantitative agreement between the model and experimental observations is found.This study is funded from ANR PANâH 2008 CATIMINHY project
Anomalous Roughening of Viscous Fluid Fronts in Spontaneous Imbibition
We report experiments on spontaneous imbibition of a viscous fluid by a model
porous medium in the absence of gravity. The average position of the interface
satisfies Washburn's law. Scaling of the interface fluctuations provides a
dynamic exponent z \simeq 3, indicative of global dynamics driven by capillary
forces. The complete set of exponents clearly shows that interfaces are not
self-affine, exhibiting distinct local and global scaling, both for time
(b=0.64\pm 0.02, b* =0.33 \pm 0.03) and space (a=1.94 \pm 0.20, a_loc=0.94 \pm
0.10). These values are compatible with an intrinsic anomalous scaling
scenario.Comment: 4 pages, 5 figure
CuIâBr Oligomers and Polymers Involving CuâS(cystamine) Bonds
The syntheses, crystal structures, and thermal properties of five cuprous bromides derived from cystamine, [NH3(CH2)2SS(CH2)2NH3]2+, here denoted by (SS), are reported. Whereas (SS)2Cu4Br8 (1) is a polar tetramer and (SS)2Cu2Br6 (2) consists of [(SS)Cu2Br6]2â dimers, α1-(SS)Cu2Br4 (3), (SS)Cu3Br5 (4), and α2-(SS)Cu2Br4 (5) are polymers; 3 and 5 are one-dimensional and 4 has a corrugated 2D network. All the compounds contain corner-shared tetrahedra with CuâBrâCu connections, and in some cases, edge-shared with double bromine bridges. The copper coordination is tetrahedral, either CuBr4 or CuBr3S, except in one case, in which trigonal geometry was encountered. Compounds 1, 2, and 4, which are synthesized at 50 °C, display CuâS bonds with the cystamine through either one or both sulfur atoms. On the other hand, 3 and 5, which are synthesized at 80 °C, do not have any. There is a high tendency to form hydrogen bonds between the polar ammonium heads of the cystamine with the bromine atoms. The range of phases experienced in this system is related to the bifunctional nature of cystamine, which is characterized by its primary ammonium ends and its disulfide bridge, and to the subtle competition between Brâ and SâS ligands towards the CuI ions, which appears to be controllable by temperature. The presence of both chiral M- and P-helicoidal conformers of cystamine in 1â5 results in racemic compounds adopting centrosymmetric structures for 1, 3, 4, and 5 but 2 adopts a noncentrosymmetric structure (P212121) resulting from the coordination of copper ions to one conformer; the other conformer is noncoordinated and acts as the counterion
Champoux, AndrĂ© et Toutant, Claude (1988) : ĂlĂ©ments dâhydrologie, Les Ăditions Le Griffon dâargile, Sainte-Foy, xvi + 262 p., 106 fig., 42 tabl., 22,50$, ISBN 2-920210-5.
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