8,019 research outputs found
Dynamical analysis on cosmology
We use a dynamical system approach to study the cosmological viability of
gravity theories. The method consists of formulating the
evolution equations as an autonomous system of ODEs, using suitable variables.
The formalism is applied to a class of models in which and its solutions and corresponding stability are
analysed in detail. New accelerating solutions that can be attractors in the
phase space are found. We also find that this class of models does not exhibit
a matter-dominated epoch, a solution which is inconsistent with current
cosmological observations.Comment: 12 pages, 4 figures. Accepted for publication in Classical and
Quantum Gravit
Multimodal Prediction based on Graph Representations
This paper proposes a learning model, based on rank-fusion graphs, for
general applicability in multimodal prediction tasks, such as multimodal
regression and image classification. Rank-fusion graphs encode information from
multiple descriptors and retrieval models, thus being able to capture
underlying relationships between modalities, samples, and the collection
itself. The solution is based on the encoding of multiple ranks for a query (or
test sample), defined according to different criteria, into a graph. Later, we
project the generated graph into an induced vector space, creating fusion
vectors, targeting broader generality and efficiency. A fusion vector estimator
is then built to infer whether a multimodal input object refers to a class or
not. Our method is capable of promoting a fusion model better than early-fusion
and late-fusion alternatives. Performed experiments in the context of multiple
multimodal and visual datasets, as well as several descriptors and retrieval
models, demonstrate that our learning model is highly effective for different
prediction scenarios involving visual, textual, and multimodal features,
yielding better effectiveness than state-of-the-art methods
Testing indirect methods to infer hydraulic conductivity in streambed sediments: preliminary results
Hydraulic conductivity, grain-size parameters, empirical approach, Kozeny-Carman model
Meister Eckhart: Pandangan Teologisnya
Meister Eckhart is a German philosopher, theologian, and mystician of the 13th - 14th century, who has various important perspectives on the philosophical-theological (Human Being-God), spiritual and of course mystical concerning the unity of the soul with God through self-detachment. For Eckhart, Being is identical with God Himself as the only reality. All things outside God are nothingness. This figure was influential in his day, though not free from some excesses of his views that are considered controversial and make his teaching labeled as heresy by the authority of the Church. Nevertheless, his various philosophical-theological, and spiritual insights concerning the concept of Deity, especially in the mystical level, are very relevant to be experienced both in the context of theological studies and the development of spiritual life
Investigations of Carbon Nitride-Supported Mn3O4 Oxide Nanoparticles for ORR
Earth-abundant Mn-based oxide nanoparticles are supported on carbon nitride using two different immobilization methods and tested for the oxygen reduction reaction. Compared to the metal free CN, the immobilization of Mn oxide enhances not only the electrocatalytic activity but also the selectivity towards the 4e- reduction reaction of O-2 to H2O. The XPS analysis reveals the interaction of the pyridine N species with Mn3O4 nanoparticles being particularly beneficial. This interaction is realized-although to a limited extent-when preparing the catalysts via impregnation; via the oleic acid route it is not observed. Whilst this work shows the potential of these systems to catalyze the ORR, the main limiting factor is still the poor conductivity of the support which leads to overpotential
Investigation of rpoS and dps genes in sodium hypochlorite resistance of Salmonella Enteritidis SE86 isolated from foodborne illness outbreaks in southern Brazil.
In Rio Grande do Sul, southern Brazil, Salmonella Enteritidis is one of the principal microorganisms responsible for foodborne disease. The present study was conducted to compare the sodium hypochlorite resistance of Salmonella Enteritidis SE86 with that of other strains of Salmonella Enteritidis isolated from different regions of the world and to investigate the involvement of the rpoS and dps genes in resistance to this disinfectant. We tested five Salmonella Enteritidis wild-type (WT) strains isolated from different countries, two mutant strains of Salmonella Enteritidis SE86, and two tagged (3XFLAG) strains of Salmonella Enteritidis SE86 for their resistance to sodium hypochlorite (200 ppm). The survival of the WT and attenuated strains was determined based on bacterial counts, and tagged proteins (Dps and RpoS) were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with anti-FLAG antibodies. None of the WT strains of Salmonella Enteritidis were totally inactivated after 20 min. The SE86 strain lacking dps was more sensitive to sodium hypochlorite than was the WT SE86 strain, with a 2-log reduction in counts after 1 min. The RpoS and Dps proteins were actively expressed under the conditions tested, indicating that in Salmonella Enteritidis SE86 these genes, which are expressed when in contact with sodium hypochlorite, are related to oxidative stress
Does the use of face masks during the COVID-19 pandemic impact on oral hygiene habits, oral conditions, reasons to seek dental care and esthetic concerns?
To evaluate the impact of the use of face masks on oral hygiene habits; oral conditions self-perception; reasons to seek dental treatment; and esthetic concerns. 1346 participants answered a web-based survey with questions related to the aims of the stu
Evaluation of the physicochemical and antibacterial properties of experimental adhesives doped with lithium niobate
The aim of the present study was to formulate dental adhesives with different concentrations of LiNbO3 and to evaluate their physicochemical and antibacterial properties. A dental adhesive was formulated using methacrylate monomers and photoinitiators and used as a control filler-free group. Subsequently, three experimental adhesives doped with LiNbO3 at different concentrations (1 wt.%, 2 wt.%, and 5 wt.%) were also formulated. All the experimental adhesives were assessed to evaluate the degree of conversion (DC), softening in solvent, immediate and long-term microtensile bond-strength (μ-TBS), radiopacity, ultimate tensile strength, and antibacterial activity. The incorporation of 1 wt.% of LiNbO3 had no negative effect on the DC of the adhesive resin compared to the control group (p > 0.05). We observed a decrease in the percentage of softening in solvent in the group LiNbO3 at 1 wt.% (p 0.05). After six months, the group with 5 wt.% still presented the highest μ-TBS (p 0.05). LiNbO3 was successfully incorporated in dental adhesives, increasing the radiopacity and their resistance to degradation. Although LiNbO3 offered no antibacterial properties, the reliability of LiNbO3 incorporation in the adhesive encourages new tests to better investigate the antimicrobial action of LiNbO3 through temperature variation
Differential Midgut Attachment of Leishmania (Viannia) braziliensis in the Sand Flies Lutzomyia (Nyssomyia) whitmani and Lutzomyia (Nyssomyia) intermedia
The interaction between Leishmania and sand flies has been demonstrated in many Old and New World species. Besides the morphological differentiation from procyclic to infective metacyclic promastigotes, the parasite undergoes biochemical transformations in its major surface lipophosphoglycan (LPG). An upregulation of β-glucose residues was previously shown in the LPG repeat units from procyclic to metacyclic phase in Leishmania (Viannia) braziliensis, which has not been reported in any Leishmania species. LPG has been implicated as an adhesion molecule that mediates the interaction with the midgut epithelium of the sand fly in the Subgenus Leishmania. These adaptations were explored for the first time in a species from the Subgenus Viannia, L. (V.) braziliensis with its natural vectors Lutzomyia (Nyssomyia) intermedia and Lutzomyia (Nyssomyia) whitmani. Using two in vitro binding techniques, phosphoglycans (PGs) derived from procyclic and metacyclic parasites were able to bind to the insect midgut and inhibit L. braziliensis attachment. Interestingly, L. braziliensis procyclic parasite attachment was ∼11-fold greater in the midgut of L. whitmani than in L. intermedia. The epidemiological relevance of L. whitmani as a vector of American Cutaneous Leishmaniasis (ACL) in Brazil is discussed
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