1,455 research outputs found
Bacteriophage and their potential roles in the human oral cavity.
The human oral cavity provides the perfect portal of entry for viruses and bacteria in the environment to access new hosts. Hence, the oral cavity is one of the most densely populated habitats of the human body containing some 6 billion bacteria and potentially 35 times that many viruses. The role of these viral communities remains unclear; however, many are bacteriophage that may have active roles in shaping the ecology of oral bacterial communities. Other implications for the presence of such vast oral phage communities include accelerating the molecular diversity of their bacterial hosts as both host and phage mutate to gain evolutionary advantages. Additional roles include the acquisitions of new gene functions through lysogenic conversions that may provide selective advantages to host bacteria in response to antibiotics or other types of disturbances, and protection of the human host from invading pathogens by binding to and preventing pathogens from crossing oral mucosal barriers. Recent evidence suggests that phage may be more involved in periodontal diseases than were previously thought, as their compositions in the subgingival crevice in moderate to severe periodontitis are known to be significantly altered. However, it is unclear to what extent they contribute to dysbiosis or the transition of the microbial community into a state promoting oral disease. Bacteriophage communities are distinct in saliva compared to sub- and supragingival areas, suggesting that different oral biogeographic niches have unique phage ecology shaping their bacterial biota. In this review, we summarize what is known about phage communities in the oral cavity, the possible contributions of phage in shaping oral bacterial ecology, and the risks to public health oral phage may pose through their potential to spread antibiotic resistance gene functions to close contacts
Pluripolarity of Graphs of Denjoy Quasianalytic Functions of Several Variables
In this paper we prove pluripolarity of graphs of Denjoy quasianalytic
functions of several variables on the spanning se
Spontal-N: A Corpus of Interactional Spoken Norwegian
Spontal-N is a corpus of spontaneous, interactional Norwegian. To our knowledge, it is the first corpus of Norwegian in which the majority of speakers have spent significant parts of their lives in Sweden, and in which the recorded speech displays varying degrees of interference from Swedish. The corpus consists of studio quality audio- and video-recordings of four 30-minute free conversations between acquaintances, and a manual orthographic transcription of the entire material. On basis of the orthographic transcriptions, we automatically annotated approximately 50 percent of the material on the phoneme level, by means of a forced alignment between the acoustic signal and pronunciations listed in a dictionary. Approximately seven percent of the automatic transcription was manually corrected. Taking the manual correction as a gold standard, we evaluated several sources of pronunciation variants for the automatic transcription. Spontal-N is intended as a general purpose speech resource that is also suitable for investigating phonetic detail
A Microscale Technique for Gas Chromatography-Mass Spectrometry Measurements of Picogram Amounts of Indole-3-Acetic Acid in Plant Tissues
Veterinarians in the UK on the use of non-steroidal anti-inflammatory drugs (NSAIDs) for post-disbudding analgesia of calves
<p>Top 20 down-regulated genes after DAPT treatment in P0 Lfng-GFP<sup>+</sup> cells.</p
Renormalization of cellular automata and self-similarity
We study self-similarity in one-dimensional probabilistic cellular automata
(PCA) using the renormalization technique. We introduce a general framework for
algebraic construction of renormalization groups (RG) on cellular automata and
apply it to exhaustively search the rule space for automata displaying dynamic
criticality. Previous studies have shown that there exists several exactly
renormalizable deterministic automata. We show that the RG fixed points for
such self-similar CA are unstable in all directions under renormalization. This
implies that the large scale structure of self-similar deterministic elementary
cellular automata is destroyed by any finite error probability. As a second
result we show that the only non-trivial critical PCA are the different
versions of the well-studied phenomenon of directed percolation. We discuss how
the second result supports a conjecture regarding the universality class for
dynamic criticality defined by directed percolation.Comment: 14 pages, 4 figure
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