5,743 research outputs found
Characterization of bacteriophage communities and CRISPR profiles from dental plaque.
BackgroundDental plaque is home to a diverse and complex community of bacteria, but has generally been believed to be inhabited by relatively few viruses. We sampled the saliva and dental plaque from 4 healthy human subjects to determine whether plaque was populated by viral communities, and whether there were differences in viral communities specific to subject or sample type.ResultsWe found that the plaque was inhabited by a community of bacteriophage whose membership was mostly subject-specific. There was a significant proportion of viral homologues shared between plaque and salivary viromes within each subject, suggesting that some oral viruses were present in both sites. We also characterized Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) in oral streptococci, as their profiles provide clues to the viruses that oral bacteria may be able to counteract. While there were some CRISPR spacers specific to each sample type, many more were shared across sites and were highly subject specific. Many CRISPR spacers matched viruses present in plaque, suggesting that the evolution of CRISPR loci may have been specific to plaque-derived viruses.ConclusionsOur findings of subject specificity to both plaque-derived viruses and CRISPR profiles suggest that human viral ecology may be highly personalized
Factors that influence the process of formation of the olympic judokas
Con el objetivo de analizar los factores que influyen en el proceso de formación deportiva de los judokas españoles olímpicos, se aplicó una entrevista semiestructurada de 52 preguntas agrupadas en 6 dimensiones (Contexto Deportivo, Contexto Social, Proceso de Formación, Psicológica, Técnico-táctica, Condición Física). Los resultados muestran que los judokas olímpicos se iniciaron en la práctica del Judo a los 6,90 ± 3,02 años, concretamente las mujeres a los 6,80 ± 2,88 años y los hombres algo más tarde, a los 7 ± 3,42 años, el 95% (n=19) influenciados, fundamentalmente, por un familiar. Además, destaca que ninguno de los entrevistados consiguió medalla en categorías inferiores. Para el 75% (n=15) de los judokas olímpicos es muy importante llevar una sincronización del entrenamiento técnico-táctico, de la condición física y de los aspectos psicológicos de forma integradaWith the aim of analizing the factors that have an influence on the sports training process of the olympic Spanish judokas, a semistructured interview of 52 questions grouped in 6 aspects was carried out: Sports Context, Social Context, Training Process, Psychological Condition, Technical-Tactical Condition and Physical Conditon). The results show that olympic judokas began practising judo at the age of 6.90 ± 3.02 years. Specifically, women started at the age of 6.80 ± 2.88, and men slightly later, at the age of 7 ± 3.42 years. 95% (n=19) of them were mainly influenced by a relative. Moreover, it is to be highlighted that none of the interviewees won a medal in low categories. For 75% (n=15) of the olympic judokas, it is very important that technical-tactical training, physical condition training and psychological aspects be synchronised in an integrated wa
Engaging without over-powering: A case study of a FLOSS project
This is the post-print version of the published chapter. The original publication is available at the link below. Copyright @ 2010 IFIP International Federation for Information Processing.The role of Open Source Software (OSS) in the e-learning business has become more and more fundamental in the last 10 years, as long as corporate and government organizations have developed their educational and training programs based on OSS out-of-the-box tools. This paper qualitatively documents the decision of the largest UK e-learning provider, the Open University, to adopt the Moodle e-learning system, and how it has been successfully deployed in its site after a multi-million investment. A further quantitative study also provides evidence of how a commercial stakeholder has been engaged with, and produced outputs for, the Moodle community. Lessons learned from this experience by the stakeholders include the crucial factors of contributing to the OSS community, and adapting to an evolving technology. It also becomes evident how commercial partners helped this OSS system to achieve the transition from an “average” OSS system to a successful multi-site, collaborative and community-based OSS project
Spin configuration in a frustrated ferromagnetic/antiferromagnetic thin film system
We have studied the magnetic configuration in ultrathin antiferromagnetic Mn
films grown around monoatomic steps on an Fe(001) surface by spin-polarized
scanning tunneling microscopy/spectroscopy and ab-initio-parametrized
self-consistent real-space tight binding calculations in which the spin
quantization axis is independent for each site thus allowing noncollinear
magnetism. Mn grown on Fe(001) presents a layered antiferromagnetic structure.
In the regions where the Mn films overgrows Fe steps the magnetization of the
surface layer is reversed across the steps. Around these defects a frustration
of the antiferromagnetic order occurs. Due to the weakened magnetic coupling at
the central Mn layers, the amount of frustration is smaller than in Cr and the
width of the wall induced by the step does not change with the thickness, at
least for coverages up to seven monolayers.Comment: 10 pages, 5 figure
Belnap-Dunn semantics for natural implicative expansions of Kleene's strong three-valued matrix with two designated values
27 p.A conditional is natural if it fulfils the three following conditions. (1) It coincides with the classical conditional when restricted to the classical values T and F; (2) it satisfies the Modus Ponens; and (3) it is assigned a designated value whenever the value assigned to its antecedent is less than or equal to the value assigned to its consequent. The aim of this paper is to provide a ‘bivalent’ Belnap-Dunn semantics for all natural implicative expansions of Kleene's strong 3-valued matrix with two designated elements. (We understand the notion ‘natural conditional’ according to N. Tomova, ‘A lattice of implicative extensions of regular Kleene's logics’, Reports on Mathematical Logic, 47, 173–182, 2012.)S
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