920 research outputs found
The periodontium of periodontitis patients contains citrullinated proteins which may play a role in ACPA (anti-citrullinated protein antibody) formation
Aim To determine the presence and location (stroma versus epithelium) of citrullinated proteins in periodontitis tissue as compared to non-periodontitis tissue and synovial tissue of RA patients. Materials & Methods Periodontitis, healthy periodontal and RA-affected synovial tissue samples were collected in addition to buccal swabs. These samples were stained for the presence of citrullinated proteins using polyclonal (Ab5612) and monoclonal (F95) antibodies. Furthermore, Western blotting with F95 was performed on lysates prepared from periodontal and synovial tissues. Results In periodontitis stroma, increased citrullinated protein presence (80%) was observed compared with control stroma (33%), the latter was associated with inflammation of non-periodontitis origin. Periodontal epithelium always stained positive for Ab5612. Noteworthy, only periodontitis-affected epithelium stained positive for F95. All buccal mucosal swabs and 3 of 4 synovial tissue samples stained positive for both Ab5612 and F95. Western blotting with F95 showed presence of similar citrullinated proteins in both periodontitis and RA-affected synovial tissue. Conclusion Within the periodontal stroma, citrullination is an inflammation-depended process. In periodontal epithelium, citrullination is a physiological process. Additional citrullinated proteins are formed in periodontitis, apparently similar to those formed in RA-affected synovial tissue. Periodontitis induced citrullination may play a role in the aetiology of rheumatoid arthritis
Genomic-based epidemiology reveals independent origins and gene flow of glyphosate resistance in Bassia scoparia populations across North America
Genomic-based epidemiology can provide insight into the origins and spread of herbicide resistance mechanisms in weeds. We used kochia (Bassia scoparia) populations resistant to the herbicide glyphosate from across western North America to test the alternative hypotheses that (i) a single EPSPS gene duplication event occurred initially in the Central Great Plains and then subsequently spread to all other geographical areas now exhibiting glyphosate-resistant kochia populations or that (ii) gene duplication occurred multiple times in independent events in a case of parallel evolution. We used qPCR markers previously developed for measuring the structure of the EPSPS tandem duplication to investigate whether all glyphosate-resistant individuals had the same EPSPS repeat structure. We also investigated population structure using simple sequence repeat markers to determine the relatedness of kochia populations from across the Central Great Plains, Northern Plains and the Pacific Northwest. We found that the original EPSPS duplication genotype was predominant in the Central Great Plains where glyphosate resistance was first reported. We identified two additional EPSPS duplication genotypes, one having geographical associations with the Northern Plains and the other with the Pacific Northwest. The EPSPS duplication genotype from the Pacific Northwest seems likely to represent a second, independent evolutionary origin of a resistance allele. We found evidence of gene flow across populations and a general lack of population structure. The results support at least two independent evolutionary origins of glyphosate resistance in kochia, followed by substantial and mostly geographically localized gene flow to spread the resistance alleles into diverse genetic backgrounds
Diversidade genética de plantas daninhas revelada por AFLP. I. Proso Millet (Panicum miliaceum, L.).
bitstream/CNPMS/16151/1/Com_71.pd
Genetic diversity among proso millet (Panicum miliaceum) biotypes assessed by AFLP technique.
A técnica de AFLP (Amplified Fragment Length Polymorphism) foi empregada para acessar a diversidade genética entre três biótipos domesticados e nove biótipos selvagens de proso millet dos Estados Unidos e do Canadá. Oito combinações de primers detectaram 39 fragmentos polimórficos de DNA, e a estimativa da distância genética entre os biótipos variou de 0,02 a 0,04. Colorado-Weld County de sementes pretas e Wyoming-Platte County foram os biótipos mais distintos de acordo com o índice de dissimilaridade. A análise de cluster por UPGMA revelou dois grupos distintos de proso millet mas sem nenhuma relação geográfica. Seis biótipos selvagens que exibiam algumas características de plantas cultivadas foram agrupados juntamente com os biótipos domesticados de proso millet, enquanto os três fenótipos tipicamente selvagens formaram outro grupo distinto por marcadores AFLP
Is green space in the living environment associated with people's feelings of social safety?
Abstract.
The authors investigate whether the percentage of green space in people's living environ-
ment affects their feelings of social safety positively or negatively. More specifically they investigate
the extent to which this relationship varies between urban and rural areas, between groups in the
community that can be identified as more or less vulnerable, and the extent to which different types of
green space exert different influences. The study includes 83736 Dutch citizens who were interviewed
about their feelings of social safety. The percentage of green space in the living environment of each
respondent was calculated, and data analysed by use of a three-level latent variable model, controlled
for individual and environmental background characteristics. The analyses suggest that more green
space in people's living environment is associated with enhanced feelings of social safetyöexcept in
very strongly urban areas, where enclosed green spaces are associated with reduced feelings of social
safety. Contrary to the common image of green space as a dangerous hiding place for criminal activity
which causes feelings of insecurity, the results suggest that green space generally enhances feelings of
social safety. The results also suggest, however, that green space in the most urban areas is a matter
of concern with respect to social safety.
Scaling solutions and geodesics in moduli space
In this paper we consider cosmological scaling solutions in general
relativity coupled to scalar fields with a non-trivial moduli space metric. We
discover that the scaling property of the cosmology is synonymous with the
scalar fields tracing out a particular class of geodesics in moduli space -
those which are constructed as integral curves of the gradient of the log of
the potential. Given a generic scalar potential we explicitly construct a
moduli metric that allows scaling solutions, and we show the converse - how one
can construct a potential that allows scaling once the moduli metric is known.Comment: 10 pages, 3 figure
Dynamics of Generalized Assisted Inflation
We study the dynamics of multiple scalar fields and a barotropic fluid in an
FLRW-universe. The scalar potential is a sum of exponentials. All critical
points are constructed and these include scaling and de Sitter solutions. A
stability analysis of the critical points is performed for generalized assisted
inflation, which is an extension of assisted inflation where the fields
mutually interact. Effects in generalized assisted inflation which differ from
assisted inflation are emphasized. One such a difference is that an
(inflationary) attractor can exist if some of the exponential terms in the
potential are negative.Comment: 27 page
Scaling Cosmologies of N=8 Gauged Supergravity
We construct exact cosmological scaling solutions in N=8 gauged supergravity.
We restrict to solutions for which the scalar fields trace out geodesic curves
on the scalar manifold. Under these restrictions it is shown that the axionic
scalars are necessarily constant. The potential is then a sum of exponentials
and has a very specific form that allows for scaling solutions. The scaling
solutions describe eternal accelerating and decelerating power-law universes,
which are all unstable. An uplift of the solutions to 11-dimensional
supergravity is carried out and the resulting timedependent geometries are
discussed. In the discussion we briefly comment on the fact that N=2 gauged
supergravity allows stable scaling solutions.Comment: 17 pages; referenced added, reportnr changed and some corrections in
section
Artificial coherent states of light by multi-photon interference in a single-photon stream
Coherent optical states consist of a quantum superposition of different
photon number (Fock) states, but because they do not form an orthogonal basis,
no photon number states can be obtained from it by linear optics. Here we
demonstrate the reverse, by manipulating a random continuous single-photon
stream using quantum interference in an optical Sagnac loop, we create
engineered quantum states of light with tunable photon statistics, including
approximate weak coherent states. We demonstrate this experimentally using a
true single-photon stream produced by a semiconductor quantum dot in an optical
microcavity, and show that we can obtain light with in
agreement with our theory, which can only be explained by quantum interference
of at least 3 photons. The produced artificial light states are, however, much
more complex than coherent states, containing quantum entanglement of photons,
making them a resource for multi-photon entanglement.Comment: 6 pages + supplemental materia
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