Results 111 to 120 of about 3,116,462 (307)

A pattern sequence approach to Stern’s sequence

open access: yesDiscrete Mathematics, 2011
Let w be a binary string and let a_w (n) be the number of occurrences of the word w in the binary expansion of n. As usual we let s(n) denote the Stern sequence; that is, s(0)=0, s(1)=1, and for n >= 1, s(2n)=s(n) and s(2n+1)=s(n)+s(n+1). In this note, we show that s(n) = a_1 (n) + \sum_{w in 1 (0+1)*} s([w bar]) a_{w1} (n) where w bar denotes the ...
Michael Coons, Jeffrey O. Shallit
openaire   +4 more sources

Hahn's generalized problem and corresponding Appell sequences [PDF]

open access: yes, 2008
This thesis is devoted to some aspects of the theory of orthogonal polynomials, paying a special attention to the classical ones (Hermite, Laguerre, Bessel and Jacobi).
Loureiro, Ana F.
core  

Functional comparison of EncB and EncC cargo proteins in iron storage within the Myxococcus xanthus encapsulin

open access: yesFEBS Letters, EarlyView.
Encapsulins are protein nanocompartments that play an important role in iron storage. In the Myxococcus xanthus encapsulin system, two cargo proteins called EncB and EncC contribute to iron mineralization. Here, we show that EncB and EncC generate iron‐containing minerals with distinct chemical compositions, suggesting that the composition of stored ...
Harry B. McDowell   +2 more
wiley   +1 more source

Eocene Stratigraphic Sequences in the Prebetic of Alicante (SE Spain) and Their Correlation with Global Sea-Level and Climatic Curves

open access: yesJournal of Marine Science and Engineering
The Onil and Ibi sections (Prebetic Zone, Betic Cordillera: Alicante, SE Spain) record a late Ypresian (Cuisian) to early Lutetian (~51 to ~43 Myr) carbonate platform succession, dated using larger benthic foraminifera (LBF) and planktonic foraminifera ...
Crina Miclăuș   +4 more
doaj   +1 more source

A new additive function and the Smarandache divisor product sequences [PDF]

open access: yes, 2009
The main purpose of this paper is using the elementary method and the prime distribution theory to study the mean value properties of G(n) in Smarandache divisor product sequences fpd(n)g and fqd(n)g, and give two sharper asymptotic formulae for ...
Weili, Yao   +3 more
core   +1 more source

Structural and biochemical analysis of a B12 superbinder

open access: yesFEBS Letters, EarlyView.
BtuG proteins are vitamin B12 scavengers in Bacteroides thetaiotaomicron, a dominant human gut bacterium. We present crystal structures of three BtuG homologs bound to cobalamin and its precursor cobinamide, revealing picomolar binding affinities, among the highest known for any natural protein.
Jose M. Martinez Felices   +3 more
wiley   +1 more source

nCk sequences and their difference sequences

open access: yesCoRR, 2015
A nCk sequence is a sequence of n-bit numbers with k bits set. Given such a sequence C, the difference sequence D of C is subject to certain regularities that make it possible to generate D in 2|C| time, and, hence, to generate C in 3|C| time.
openaire   +3 more sources

Structures of mycobacterial 3‐methylcrotonyl‐CoA carboxylase reveal carrier‐domain translocation between catalytic sites

open access: yesFEBS Letters, EarlyView.
Mycobacterial 3‐methylcrotonyl‐CoA carboxylase uses a mobile biotin‐carrying domain to shuttle a carboxyl group between two catalytic sites, enabling carboxylation of 3‐methylcrotonyl‐CoA during leucine breakdown. Cryo‐electron microscopy captures the carrier at both sites and reveals an inward loop movement that may prevent futile rebinding to the ...
Ajit Yadav   +2 more
wiley   +1 more source

From junk to function — How weak selection in eukaryotes builds new parts and drives genomic complexity

open access: yesFEBS Letters, EarlyView.
How do genomes gain new functional parts? In eukaryotes, which tend to evolve under weak selection, much of the genome is junk. Palazzo and Qiu borrow the logic of Markov chains to show how non‐functional DNA becomes functional through the appearance of intermediate states, which arise due to epistasis, buffering, and biochemical messiness, allowing ...
Alexander F. Palazzo, Yi Qiu
wiley   +1 more source

The Shewanella oneidensis Fic enzyme SoFic targets the switch‐I region of EF‐Tu for AMPylation

open access: yesFEBS Letters, EarlyView.
Fic enzymes mediate diverse post‐translational modifications across all domains of life, including AMPylation. Prokaryotic EF‐Tu can be AMPylated and deAMPylated by the conserved Fic enzyme SoFic. Structural and biochemical approaches were used to characterize the effect of AMPylation on EF‐Tu, SoFic's enzymatic activities, and the enzyme‐target ...
Svenja Runge   +6 more
wiley   +1 more source

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