2,263 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
Emulsion formation and stabilization by biomolecules: the leading role of cellulose
Emulsion stabilization by native cellulose has been mainly hampered because of its insolubility in water. Chemical modification is normally needed to obtain water-soluble cellulose derivatives. These modified celluloses have been widely used for a range of applications by the food, cosmetic, pharmaceutic, paint and construction industries. In most cases, the modified celluloses are used as rheology modifiers (thickeners) or as emulsifying agents. In the last decade, the structural features of cellulose have been revisited, with particular focus on its structural anisotropy (amphiphilicity) and the molecular interactions leading to its resistance to dissolution. The amphiphilic behavior of native cellulose is evidenced by its capacity to adsorb at the interface between oil and aqueous solvent solutions, thus being capable of stabilizing emulsions. In this overview, the fundamentals of emulsion formation and stabilization by biomolecules are briefly revisited before different aspects around the emerging role of cellulose as emulsion stabilizer are addressed in detail. Particular focus is given to systems stabilized by native cellulose, either molecularly-dissolved or not (Pickering-like effect).Financially support by the Portuguese Foundation for Science and Technology, FCT, via the projects PTDC/AGR-TEC/4814/2014, PTDC/ASP-SIL/30619/2017 and researcher grant IF/01005/2014. RISE Research Institutes of Sweden AB and PERFORM, a competence platform in Formulation Science at RISE, are acknowledged for additional financing. This research has been supported by
Treesearch.se.info:eu-repo/semantics/publishedVersio
Visual storytelling of scientific data: collaborations between physics and graphic design in the college classroom
The Common Problem Pedagogy (CPP) project, a learning initiative implemented in four SUNY schools, aims to provide students with multidisciplinary, project-based experiences, and to foster a culture of such pedagogy among faculty. This work describes one CPP project that was conducted at SUNY Cortland during the Spring 2019 semester that brought together students from physics and graphic design disciplines. The goal of this project was to identify issues of environmental and social concern, develop numerical models to represent the effects of possible policy actions, and to communicate the meaning of this work as infographics suitable for a non-expert, public audience. This article discusses the project structure and organization, the numerical modeling work, the design process and creation of infographics, concluding with reflections on the points of success and plans for further development
A multidisciplinary collaboration between graphic design and physics classes responding to COVID-19
Students from graphic design and physics classes at SUNY Cortland collaborated during the spring semester of 2020 on a multidisciplinary project related to the COVID-19 pandemic. In these collaborations, the students’ individual contributions were part of a larger project that required a diverse skill set, through which students learned how different skills can complement their own disciplines. The graphic design and physics instructors applied a project-based learning philosophy applying the Common Problem Pedagogy (CPP) framework to construct student-teams composed of both disciplines. This project explored how coordinated social actions can allow the public to exercise control in uncertain times. Students created mathematical models related to the spread of the disease and the economic consequences of quarantine and then communicated the results in scientific reports, which were interpreted and presented as infographics and illustrative visual design posters for public outreach. To share the students’ work with the larger community the instructors concluded this project with a virtual public exhibition hosted by the SUNY Cortland Dowd Gallery
Chiral surfaces self-assembling in one-component systems with isotropic interactions
We show that chiral symmetry can be broken spontaneously in one-component
systems with isotropic interactions, i.e. many-particle systems having maximal
a priori symmetry. This is achieved by designing isotropic potentials that lead
to self-assembly of chiral surfaces. We demonstrate the principle on a simple
chiral lattice and on a more complex lattice with chiral super-cells. In
addition we show that the complex lattice has interesting melting behavior with
multiple morphologically distinct phases that we argue can be qualitatively
predicted from the design of the interaction.Comment: 4 pages, 4 figure
Simulation of the White Dwarf -- White Dwarf galactic background in the LISA data
LISA (Laser Interferometer Space Antenna) is a proposed space mission, which
will use coherent laser beams exchanged between three remote spacecraft to
detect and study low-frequency cosmic gravitational radiation. In the low-part
of its frequency band, the LISA strain sensitivity will be dominated by the
incoherent superposition of hundreds of millions of gravitational wave signals
radiated by inspiraling white-dwarf binaries present in our own galaxy. In
order to estimate the magnitude of the LISA response to this background, we
have simulated a synthesized population that recently appeared in the
literature. We find the amplitude of the galactic white-dwarf binary background
in the LISA data to be modulated in time, reaching a minimum equal to about
twice that of the LISA noise for a period of about two months around the time
when the Sun-LISA direction is roughly oriented towards the Autumn equinox.
Since the galactic white-dwarfs background will be observed by LISA not as a
stationary but rather as a cyclostationary random process with a period of one
year, we summarize the theory of cyclostationary random processes and present
the corresponding generalized spectral method needed to characterize such
process. We find that, by measuring the generalized spectral components of the
white-dwarf background, LISA will be able to infer properties of the
distribution of the white-dwarfs binary systems present in our Galaxy.Comment: 14 pages and 6 figures. Submitted to Classical and Quantum Gravity
(Proceedings of GWDAW9
Novel self-assembled morphologies from isotropic interactions
We present results from particle simulations with isotropic medium range
interactions in two dimensions. At low temperature novel types of aggregated
structures appear. We show that these structures can be explained by
spontaneous symmetry breaking in analytic solutions to an adaptation of the
spherical spin model. We predict the critical particle number where the
symmetry breaking occurs and show that the resulting phase diagram agrees well
with results from particle simulations.Comment: 4 pages, 4 figure
Using the uncertainty principle to design simple interactions for targeted self-assembly
We present a method that systematically simplifies isotropic interactions designed for targeted self-assembly. The uncertainty principle is used to show that an optimal simplification is achieved by a combination of heat kernel smoothing and Gaussian screening of the interaction potential in real and reciprocal space. We use this method to analytically design isotropic interactions for self-assembly of complex lattices and of materials with functional properties. The derived interactions are simple enough to narrow the gap between theory and experimental implementation of theory based designed self-assembling materials
AULACOSEIRA SKVORTZOWII SP. NOV. (BACILLARIOPHYTA), A POORLY UNDERSTOOD DIATOM FROM LAKE BAIKAL, RUSSIA 1
Aulacoseira skvortzowii sp. nov. is a diatom taxon present in modern plankton assemblages and sedimentary deposits from Lake Baikal, Russia. It has been previously reported as A. islandica (O. MÜll.) Simonsen, A. islandica ssp. helvetica (O. MÜll.) Simonsen, a sporangial frustule of A. baicalensis (K. Meyer) Simonsen, and Aulacoseira “spore”. However, its microstructure, ecology, and ability to form true resting spores provide ample criteria to describe this diatom as Aulacoseira skvortzowii sp. nov.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65810/1/j.0022-3646.1996.00165.x.pd
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