Results 41 to 50 of about 105,811 (271)

Simultaneity and generalized connections in general relativity

, 2003
Stationary extended frames in general relativity are considered. The requirement of stationarity allows to treat the spacetime as a principal fiber bundle over the one-dimensional group of time translations. Over this bundle a connection form establishes
Abramowicz M A, Anandan J, Anderson S J R, Ashtekar A, Coisson R, E Minguzzi, Ellis G F R, Grøn Ø, Gödel K, Hawking S W, Klauber R, Kobayashi S, Landau L D, Malament D, Mangiarotti L, Michor P W, Minguzzi E, Minguzzi E, Märzke R F, Møller C, Poincaré H, Poincaré H, Robb A A, Sagnac M G, Sagnac M G, Sakurai J J, Semon M D, Stedman G E, Steenrod N, Strauss M, Weber T A, Will C M, Wu T T   +32 more
core   +1 more source

In situ molecular organization and heterogeneity of the Legionella Dot/Icm T4SS

FEBS Letters, EarlyView.
We present a nearly complete in situ model of the Legionella Dot/Icm type IV secretion system, revealing its central secretion channel and identifying new components. Using cryo‐electron tomography with AI‐based modeling, our work highlights the structure, variability, and mechanism of this complex nanomachine, advancing understanding of bacterial ...
Przemysław Dutka, Yuxi Liu, Stefano Maggi, Debnath Ghosal, Jue Wang, Prashant P. Damke, Stephen D. Carter, Wei Zhao, Sukhithasri Vijayrajratnam, Joseph P. Vogel, Carrie L. Shaffer, Grant J. Jensen   +11 more
wiley   +1 more source

Transferrin receptor 1‐mediated iron uptake supports thermogenic activation in human cervical‐derived adipocytes

FEBS Letters, EarlyView.
In this study, we found that human cervical‐derived adipocytes maintain intracellular iron level by regulating the expression of iron transport‐related proteins during adrenergic stimulation. Melanotransferrin is predicted to interact with transferrin receptor 1 based on in silico analysis.
Rahaf Alrifai, Mizuki Seo, Gyath Karadsheh, Fachrur Rizal Mahendra, Máté Á Demény, Ferenc Győry, János András Mótyán, László Fésüs, Endre Kristóf, Rini Arianti   +9 more
wiley   +1 more source

Reduction of Bundles, Connection, Curvature, and Torsion of the Centered Planes Space at Normalization

Mathematics, 2019
The space Π of centered m-planes is considered in projective space P n . A principal bundle is associated with the space Π and a group connection is given on the principal bundle. The connection is not uniquely induced at the
Olga Belova
doaj   +1 more source

On semistable principal bundles over a complex projective manifold, II

, 2008
Let (X, \omega) be a compact connected Kaehler manifold of complex dimension d and E_G a holomorphic principal G-bundle on X, where G is a connected reductive linear algebraic group defined over C. Let Z (G) denote the center of G.
A. Ramanathan, A. Ramanathan, B. Anchouche, C.T. Simpson, F.A. Bogomolov, G.D. Mostow, I. Biswas, Indranil Biswas, J.-P. Demailly, K. Uhlenbeck, M.F. Atiyah, S. Ramanan, S.K. Donaldson, Ugo Bruzzo   +13 more
core   +2 more sources

Structural insights into an engineered feruloyl esterase with improved MHET degrading properties

FEBS Letters, EarlyView.
A feruloyl esterase was engineered to mimic key features of MHETase, enhancing the degradation of PET oligomers. Structural and computational analysis reveal how a point mutation stabilizes the active site and reshapes the binding cleft, expading substrate scope.
Panagiota Karampa, Konstantinos Makryniotis, Theofani‐Iosifina Sousani, Evangelos Topakas, Vangelis Daskalakis, Maria Dimarogona   +5 more
wiley   +1 more source

A methionine‐lined active site governs carbocation stabilization and product specificity in a bacterial terpene synthase

FEBS Letters, EarlyView.
This study reveals a unique active site enriched in methionine residues and demonstrates that these residues play a critical role by stabilizing carbocation intermediates through novel sulfur–cation interactions. Structure‐guided mutagenesis further revealed variants with significantly altered product profiles, enhancing pseudopterosin formation. These
Marion Ringel, Carl P. O. Helmer, Shani Zev, Ronja Driller, Emily Buhr, Markus Reinbold, Renana Schwartz, Gabriel Foley, Mikael Boden, Daniel Garbe, Gerhard Schenk, Dan Thomas Major, Bernhard Loll, Thomas Brück   +13 more
wiley   +1 more source

About differential equations of the curvature tensors of a fundamental group and affine connections

Дифференциальная геометрия многообразий фигур, 2019
The principal bundle is considered, the base of which is an n-dimen­sional smooth manifold, and the typical fiber is an r-fold Lie group. Struc­ture equations for the forms of the fundamental group and affine connec­tions are given, each of which ...
N. Ryazanov
doaj   +1 more source

On 2-Holonomy

, 2012
We construct a cycle in higher Hochschild homology associated to the 2-dimensional torus which represents 2-holonomy of a non-abelian gerbe in the same way the ordinary holonomy of a principal G-bundle gives rise to a cycle in ordinary Hochschild ...
Baez, Breen, Cuntz, FRIEDRICH WAGEMANN, Giraud, HOSSEIN ABBASPOUR, Loday, Loday, Neeb, Roytenberg, Schreiber, Stasheff   +11 more
core   +1 more source

Principal bundles, groupoids, and connections [PDF]

Banach Center Publications, 2007
We clarify in which precise sense the theory of principal bundles and the theory of groupoids are equivalent; and how this equivalence of theories, in the differentiable case, reflects itself in the theory of connections. The method used is that of synthetic differential geometry. Introduction. In this note, we make explicit a sense in which the theory
openaire   +2 more sources