284 research outputs found
Effect of pulverized natural bone mineral on regeneration of three-wall intrabony defects. A preclinical study
Aims: The objective of this study is to evaluate the effects of a paste-like bone substitute material with easy handling properties and improved mechanical stability on periodontal regeneration of intrabony defects in dogs. Materials and methods: Mandibular and maxillary first and third premolars were extracted, and three-wall intrabony defects were created on second and fourth premolars. After a healing period of 3months, acute type defects were filled with a paste-like formulation of deproteinized bovine bone mineral (DBBM) (particle size, 0.125-0.25mm) in a collagenous carrier matrix (T1), pulverized DBBM (particle size, 0.125-0.25mm) without the carrier (T2), or Bio-OssÂź granules (particle size, 0.25-1.00mm) as control (C). All defects were covered with a Bio-GideÂź membrane. The dogs were sacrificed after 12weeks, and the specimens were analyzed histologically and histometrically. Results: Postoperative healing of all defects was uneventful, and no histological signs of inflammation were observed in the augmented and gingival regions. New cementum, new periodontal ligament, and new bone were observed in all three groups. The mean vertical bone gain was 3.26mm (T1), 3.60mm (T2), and 3.81mm (C). That of new cementum was 2.25mm (T1), 3.88mm (T2), and 3.53mm (C). The differences did not reach statistical significance. The DBBM particles were both incorporated in new bone and embedded in immature bone marrow. Conclusions: The results of this preclinical study showed that the 0.125-0.25-mm DBBM particles in a powder or paste formulation resulted in periodontal regeneration comparable to the commercially available DBBM. Osteoconductivity, in particular, was not affected by DBBM size or paste formulation. Clinical relevance: The improved handling properties of the paste-like bone substitute consisting of small DBBM particles embedded in a collagen-based carrier hold promise for clinical applications
Factorizations and Physical Representations
A Hilbert space in M dimensions is shown explicitly to accommodate
representations that reflect the prime numbers decomposition of M.
Representations that exhibit the factorization of M into two relatively prime
numbers: the kq representation (J. Zak, Phys. Today, {\bf 23} (2), 51 (1970)),
and related representations termed representations (together with
their conjugates) are analysed, as well as a representation that exhibits the
complete factorization of M. In this latter representation each quantum number
varies in a subspace that is associated with one of the prime numbers that make
up M
Strategies and Networks for State-Dependent Quantum Cloning
State-dependent cloning machines that have so far been considered either
deterministically copy a set of states approximately, or probablistically copy
them exactly. In considering the case of two equiprobable pure states, we
derive the maximum global fidelity of approximate clones given initial
exact copies, where . We also consider strategies which interpolate
between approximate and exact cloning. A tight inequality is obtained which
expresses a trade-off between the global fidelity and success probability. This
inequality is found to tend, in the limit as , to a known
inequality which expresses the trade-off between error and inconclusive result
probabilities for state-discrimination measurements. Quantum-computational
networks are also constructed for the kinds of cloning machine we describe. For
this purpose, we introduce two gates: the distinguishability transfer and state
separation gates. Their key properties are describedComment: 12 pages, 6 eps figures, submitted to Phys. Rev.
Mitigating seafloor disturbance of bottom trawl fisheries for North Sea sole Solea solea by replacing mechanical with electrical stimulation
Funding: ADR, NTH, PM, HP, JJP, TvK: European Maritime and Fisheries Fund (EMFF) through the Netherlands Ministry of Agriculture Nature and Food Quality (LNV) (Grand/Award Number: 1300021172); NO ADR, JD, ORE, NTH, AI, FO, HP, JJP, TvK: FP 7 project BENTHIS (grant no. 312088); NO.Peer reviewedPublisher PD
Ca2+-binding protein 2 inhibits Ca2+-channel inactivation in mouse inner hair cells
Ca2+ channels mediate excitation-secretion coupling and show little inactivation at sensory ribbon synapses, enabling reliable synaptic information transfer during sustained stimulation. Studies of Ca2+-channel complexes in HEK293 cells indicated that Ca2+-binding proteins (CaBPs) antagonize their calmodulin-dependent inactivation. Although human mutations affecting CABP2 were shown to cause hearing impairment, the role of CaBP2 in auditory function and the precise disease mechanism remained enigmatic. Here, we disrupted CaBP2 in mice and showed that CaBP2 is required for sound encoding at inner hair cell synapses, likely by suppressing Ca2+-channel inactivation. We propose that the number of activatable Ca2+ channels at the active zone is reduced when CaBP2 is lacking, as is likely the case with the newly described human CABP2 mutation
Ceding to their appetites: A taxonomy of international tourists to South Africa
Tourism is a key source of income to South Africa. Food and beverages is a
key part of tourism and the literature reveals that tourists spend up to a quarter
of their budget on cuisine. South Africa has, however, been rated as the
least-prepared culinary travel destination and the travel destination with the
greatest potential for growth. Therefore, a segmentation taxonomy based on
culinary preferences of international tourists to South Africa is put forth
which can be used to prepare South Africa as a culinary travel destination.
The 627 international tourists surveyed were divided into five segments with
the use of factor analyses, t-tests, Spearman rank correlations and analysis of
variance. The segments were named conservationists, experience seekers,
devotees, explorers and socialisers (CEDES taxonomy). Multiple results and
implications are discussed in the paper
Optimal discrimination of mixed quantum states involving inconclusive results
We propose a generalized discrimination scheme for mixed quantum states. In
the present scenario we allow for certain fixed fraction of inconclusive
results and we maximize the success rate of the quantum-state discrimination.
This protocol interpolates between the Ivanovic-Dieks-Peres scheme and the
Helstrom one. We formulate the extremal equations for the optimal positive
operator valued measure describing the discrimination device and establish a
criterion for its optimality. We also devise a numerical method for efficient
solving of these extremal equations.Comment: 5 pages, 1 figur
Decoherence, einselection, and the quantum origins of the classical
Decoherence is caused by the interaction with the environment. Environment
monitors certain observables of the system, destroying interference between the
pointer states corresponding to their eigenvalues. This leads to
environment-induced superselection or einselection, a quantum process
associated with selective loss of information. Einselected pointer states are
stable. They can retain correlations with the rest of the Universe in spite of
the environment. Einselection enforces classicality by imposing an effective
ban on the vast majority of the Hilbert space, eliminating especially the
flagrantly non-local "Schr\"odinger cat" states. Classical structure of phase
space emerges from the quantum Hilbert space in the appropriate macroscopic
limit: Combination of einselection with dynamics leads to the idealizations of
a point and of a classical trajectory. In measurements, einselection replaces
quantum entanglement between the apparatus and the measured system with the
classical correlation.Comment: Final version of the review, with brutally compressed figures. Apart
from the changes introduced in the editorial process the text is identical
with that in the Rev. Mod. Phys. July issue. Also available from
http://www.vjquantuminfo.or
Overnutrition and Scholastic Achievement: Is There a Relationship? An 8-Year Follow-Up Study
Objective: The aim of this study was to assess the association between overnutrition and scholastic achievement (SA). Methods: A representative and proportional sample of 477 children of the 5th elementary school grade of both genders was randomly chosen during 2010, in the Metropolitan Region of Chile. SA was measured through the 2009 Education Quality Measurement System (SIMCE) tests of language (LSA), mathematics (MSA) and understanding of the natural environment (UNESA). Current nutritional status was assessed through the body mass index Z-score (Z-BMI). Nutritional quality of diet, schedule exercise, socioeconomic status, family, and educational variables were also recorded. Four and 8 years later, SA was assessed through the 2013 SIMCE and the University Selection Test (2017 PSU), respectively. Results: Socioeconomic status, the number of repeated school years, and maternal schooling were strong predictors of 2009 SIMCE and the independent variables with the greatest explanatory power for LSA (Model R2 = 0.178; p 2 = 0.205; p2 = 0.272; p Conclusions: These results confirm that overnourished children did not achieve significantly lower SA
Chalk-steel Interface testing for marine energy foundations
The Energy Technology Partnership (ETP) and Lloydâs Register EMEA are gratefully acknowledged for the funding of this project. The authors would also like to acknowledge the support of the European Regional Development Fund (ERDF) SMART Centre at the University of Dundee that allowed purchase of the equipment used during this study. The views expressed are those of the authors alone, and do not necessarily represent the views of their respective companies or employing organizations.Peer reviewedPostprin
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