1,370 research outputs found
q-Differential equations for q-classical polynomials and q-Jacobi-Stirling numbers
No full textWe introduce, characterise and provide a combinatorial interpretation for the so-called q-Jacobi–Stirling numbers.
This study is motivated by their key role in the (reciprocal) expansion of any power of a second order
q-differential operator having the q-classical polynomials as eigenfunctions in terms of other even order operators,
which we explicitly construct in this work. The results here obtained can be viewed as the q-version of
those given by Everitt et al. and by the first author, whilst the combinatorics of this new set of numbers is a
q-version of the Jacobi–Stirling numbers given by Gelineau and the second author
Q(10) values vary with different kinetic properties of C mineralization
No full textTemperature response quotient (Q(10)) is a critical parameter for evaluating global additional carbon (C) release with climate change. However, its value is usually derived from time span or instantaneous rate or cumulative amount of C flux, giving a very one-sided account of thermal sensitivity of C cycling. Through a 117-day laboratory incubation study, we estimated Q(10) values simultaneously with the labile (a(0)) and recalcitrant C proportions and their rate constants, and then tested for any variances of these kinetic properties in different vegetation stands, soil horizons, aeration statuses, and thermal settings (i.e., diurnally-varying, constant low and constant high temperatures). A regularly varying temperature regime increased the exploitation of labile C resources (i.e., high a0) and required longer time spans (i.e., low rate constants). The constant high temperature induced the exhaustive depletion of the labile C pool and motivated a very rapid and short-term C mineralization process. The constant low temperature treatment was characterized by the lowest a(0) but by medium rate constants because low temperature slowed the C mineralization processes but retained high level of the original C processing diversity. Therefore, a(0), and the rate constants showed discrepancies in their temperature sensitivities as revealed by pairwise comparisons of temperature regimes. Such discrepancies were also supported by pairwise comparisons of aeration statuses, forest stands and soil horizons. The Q(10) bias between C mineralization a(0) and rate constants in this laboratory experiment is attributed to the inherently distinct properties of these two parameters, as a(0) and its Q(10) are closely correlated with the sizes of the easily available C pool, while rate constants and their Q(10), variances explain the temporal scale of the same C mineralization process. Our findings suggest a combined application of a(0) and rate constants for exploring the temperature sensitivity of C mineralization in future studies
A Comparative Assessment of Answer Quality on Four Question Answering Sites
No full textQuestion answering (Q&A) sites, where communities of volunteers answer questions, may provide faster, cheaper, and better services than traditional institutions. However, like other Web 2.0 platforms, user-created content raises concerns about information quality. At the same time, Q&A sites may provide answers of different quality because they have different communities and technological platforms. This paper compares answer quality on four Q&A sites: Askville, WikiAnswers, Wikipedia Reference Desk, and Yahoo! Answers. Findings indicate that: 1) the use of similar collaborative processes on these sites results in a wide range of outcomes. Significant differences in answer accuracy, completeness, and verifiability were found; 2) answer multiplication does not always result in better information. Answer multiplication yields more complete and verifiable answers but does not result in higher accuracy levels; and 3) a Q&A site’s popularity does not correlate with its answer quality, on all three measures
Exotic QQ(q)over-bar(q)over-bar, QQ(q)over-bar(s)over-bar, and QQ(s)over-bar(s)over-bar states
No full textAfter constructing the possible J(P) = 0(-), 0(+), 1(-), and 1(+) QQ (q) over bar(q) over bar tetraquark interpolating currents in a systematic way, we investigate the two-point correlation functions and extract the corresponding masses with the QCD sum rule approach. We study the QQ (q) over bar(q) over bar, QQ (q) over bar(s) over bar, and QQ (s) over bar(s) over bar systems with various isospins I = 0, 1/2, 1. Our numerical analysis indicates that the masses of doubly bottomed tetraquark states are below the threshold of the two-bottom mesons, two-bottom baryons, and one doubly bottomed baryon plus one antinucleon. Very probably these doubly bottomed tetraquark states are stable. DOI: 10.1103/PhysRevD.87.014003http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000313001000005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)9ARTICLE1null8
Modification of Loop 1 Affects the Nucleotide Binding Properties of Myo1c, the Adaptation Motor in the Inner Ear
No full textMyo1c is one of eight members of the mammalian myosin I family of actin-associated molecular motors. In stereocilia of the hair cells in the inner ear, Myo1c presumably serves as the adaptation motor, which regulates the opening and closing of transduction channels. Although there is conservation of sequence and structure among all myosins in the N-terminal motor domain, which contains the nucleotide- and actin-binding sites, some differences include the length and composition of surface loops, including loop 1, which lies near the nucleotide-binding domain. To investigate the role of loop 1, we expressed in insect cells mutants of a truncated form of Myo1c, Myo1c1IQ, as well as chimeras of Myo1c1IQ with the analogous loop from other myosins. We found that replacement of the charged residues in loop 1 with alanines or the whole loop with a series of alanines did not alter the ATPase activity, transient kinetics properties, or Ca2+ sensitivity of Myo1c1IQ. Substitution of loop 1 with that of the corresponding region from tonic smooth muscle myosin II (Myo1c1IQ-tonic) or replacement with a single glycine (Myo1c1IQ-G) accelerated the release of ADP from A.M 2?3-fold in Ca2+, whereas substitution with loop 1 from phasic muscle myosin II (Myo1c1IQ-phasic) accelerated the release of ADP 35-fold. Motility assays with chimeras containing a single ?-helix, or SAH, domain showed that Myo1cSAH-tonic translocated actin in vitro twice as fast as Myo1cSAH-WT and 3-fold faster than Myo1cSAH-G. The studies show that changes induced in Myo1c via modification of loop 1 showed no resemblance to the behavior of the loop donor myosins or to the changes previously observed with similar Myo1b chimeras
Exotic tetraquark states with the qq (Q)over-bar(Q)over-bar configuration
No full textIn this work, we study systematically the mass splittings of the qq (Q) over bar(Q) over bar (q = u, d, s and Q = c, b) tetraquark states with the color-magnetic interaction by considering color mixing effects and estimate roughly their masses. We find that the color mixing effect is relatively important for the J(P) = 0(+) states and possible stable tetraquarks exist in the nn (Q) over bar(Q) over bar (n = u, d) and ns (Q) over bar(Q) over bar systems either with J = 0 or with J = 1. Possible decay patterns of the tetraquarks are briefly discussed.National Natural Science Foundation of China [11175073, 11275115, 11222547, 11261130311]; 973 program; National Program for Support of Top-notch Young Professionals; Fundamental Research Funds for the Central UniversitiesSCI(E)ARTICLE107
MOHA: A Multi-Mode Hybrid Automaton Model for Learning Car-Following Behaviors
No full textThis paper proposes a novel hybrid model for learning discrete and continuous dynamics of car-following behaviors. Multiple modes representing driving patterns are identified by partitioning the model into groups of states. The model is visualizable and interpretable for car-following behavior recognition, traffic simulation, and human-like cruise control. The experimental results using the next generation simulation datasets demonstrate its superior fitting accuracy over conventional models.Accepted author manuscriptCyber Securit
Triply heavy tetraquark states with the QQ(Q)over-bar(q)over-bar configuration
No full textIn the framework of the color-magnetic interaction, we systematically investigate the mass splittings of the QQ (Q) over bar(q) over bar tetraquark states and estimate their rough masses in this work. These systems include the explicitly exotic states cc (b) over bar(q) over bar and bb (c) over bar(q) over bar and the hidden exotic states cc (c) over bar(q) over bar, cb (b) over bar(q) over bar, bc (c) over bar(q) over bar, and bb (b) over bar(q) over bar. If a state around the estimated mass region can be observed, its nature as a genuine tetraquark is favored. The strong decay patterns shown here will be helpful to the experimental search for these exotic states.National Natural Science Foundation of China [11175073, 11275115, 11222547, 11575008, 11261130311]; Fundamental Research Funds for the Central Universities; 973 program; National Program for Support of Young Top-notch ProfessionalsSCI(E)ARTICLE15
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