Interference of the blood clot on granulation tissue formation after tooth extraction. Histomorphological study in rats.

The interference of a blood clot in the first postoperative hours of dental extraction wounds was studied in rats. Sixty male albino rats were divided into two groups: Group I, immediately after extraction of right maxillary incisor the gingival mucosa was approximated and sutured; Group II, after 6 to 8 minutes postoperatively the blood clot was removed with saline irrigation and absorbent paper cones. The mucosa was then approximated and sutured. Six animals in each group were sacrificed after 12 hours, 1, 4, 7 and 10 days. There was a profound delay in healing in Group II since, although a new blood clot was later formed, it was not organized. The quality and the constitution, maintenance and retraction of the clot are the regulating factors in connective tissue formation during alveolar healing.

Interference competition and scavenging by Crematogaster ants (Hymenoptera: Formicidae) associated with the webs of the social spider Anelosimus eximius (Araneae: Theridiidae) in the central Amazon

Crematogaster cf. victima is a common inhabitant in the sheet web nests of the social spider Anelosimus eximius in the central Amazon basin near Manaus. A number of other ant species were found foraging on the non-sticky webs of A. eximius, but none of these reached the web occupation frequency found in C. cf. victima, nor, with the exception of an unidentified species of Pheidole, did they form satellite nests in the web, as did this species. Many prey which escaped the knock-down threads of the sheet web of A. eximius colonies were captured by ants in the lower web portions which they dominated. Furthermore, prey which were rejected by A. eximius, especially large, heavily sclerotized beetles, were also consumed by this ant. Repeated observations and experiments suggest that C. cf. victima is able to deter A. eximius activity through aerial venom release. Resources lost by A. eximius colonies to ants, especially C. cf. victima, in colonial web area and prey, may pose significant costs and may reduce colony growth.

Interference phenomenon for the Faddeevian regularization of 2D chiral fermionic determinants

The classification of the regularization ambiguity of a 2D fermionic determinant in three different classes according to the number of second-class constraints, including the new Faddeevian regularization, is examined and extended. We find a new and important result that the Faddeevian class, with three second-class constraints, possesses a free continuous one parameter family of elements. The criterion of unitarity restricts the parameter to the same range found earlier by Jackiw and Rajaraman for the two-constraint class. We studied the restriction imposed by the interference of right-left modes of the chiral Schwinger model (χQED2) using Stone's soldering formalism. The interference effects between right and left movers, producing the massive vectorial photon, are shown to constrain the regularization parameter to belong to the four-constraint class which is the only nonambiguous class with a unique regularization parameter. ©1999 The American Physical Society.

Interference phenomena, chiral bosons, and Lorentz invariance

We have studied the theory of gauged chiral bosons and proposed a general theory, a master action, that encompasses different kinds of gauge field couplings in chiral bosonized theories with first-class chiral constraints. We have fused opposite chiral aspects of this master action using the soldering formalism and applied the final action to several well-known models. The Lorentz rotation permitted us to fix conditions on the parameters of this general theory in order to preserve the relativistic invariance. We also have established some conditions on the arbitrary parameter concerned in a chiral Schwinger model with a generalized constraint, investigating both covariance and Lorentz invariance. The results obtained supplement the one that shows the soldering formalism as a new method of mass generation. ©2001 The American Physical Society.

Reciprocal interference between ants and stingless bees attending the honeydew-producing homopteran Aetalion reticulatum (Homoptera: Aetalionidae)

We evaluated the reciprocal effects between foragers of the ants Camponotus crassus and of the stingless bees Trigona hyalinata on aggregations of the honeydew-producing treehopper Aetalion reticulatum. The interactions were observed in Bauhinia variegata (Caesalpiniaceae) and Mangifera indica (Anacardiaceae) trees. We recorded the presence/absence of each attendant species in homopteran aggregations to test if the observed co-occurrence is lower than that expected by chance. An exclusion experiment was performed in which each attendant species was excluded from aggregations in order to test if an attendant species is more likely to occupy aggregations where the other attendant is not present. We also recorded the number of individuals of each attendant species in homopteran aggregations to search for any correlation between homopteran and attendant abundances. Additionally, we performed experiments using termites (Termitidae, Isoptera) as models to verify if the attendant species have the potential to defend A. reticulatum against natural enemies. The co-occurrence of attendant species was lower than that expected by chance. Homopteran aggregations without stingless bees were more visited by ants than those in which T. hyalinata was present, and vice-versa. The abundance of stingless bees was proportional to homopteran abundance, while ants abundance was not correlated to homopteran abundance. Both attendant species attacked the natural enemies models when we glued the termites ca. 1 cm away from homopteran aggregations, but only ants removed termites glued 5-7 cm away from aggregations. We suggest that the effects of non-formicid attendants should be included as another factor influencing the costs and benefits of ant-homopteran interactions, since honeydew availability for ants also depends on the presence and behavior of interspecific attendants.

Interference of epicuticular wax from leaves of grasses in selection and preparation of substrate for cultivation of symbiont fungus by Atta capiguara (Hym. Formicidae)

The selection of plants is one of the stages of foraging behavior, executed by leaf-cutting ants for the cultivation of symbiont fungus. Anatomical, biochemical and physiological characteristics of vegetal species are some of the factors that influence selection of substrate; however, most studies described in the literature refer to leaf-cutting ants. Due to the scarcity of studies on the role of epicuticular waxes of grasses in relation to foraging behavior of monocotyledonous leaf-cutters, we completed three experiments with the ant species Atta capiguara in which we analyzed: the attractiveness or selectivity of leaves of Saccharum officinarum (sugarcane) and/or Hypharrenia rufa (capim jaraguá), with and without epicuticular wax in relation to the worker of this ant species, their processing and elimination in the form of pellets of epicuticular wax from the referred fragments removed by the workers for cultivation of symbiont fungus. We observed that vegetal fragments without wax were those most transported by workers to the inside of the nests; that they processed the fragments equally with as much as without wax, and eliminated, in the form of pellets, wax removed from the same into garbage chambers of the colonies, leading us to conclude that for monocotyledonous leaf-cutters, epicuticular wax from vegetal leaves has great importance in vegetal integrity by being used as substrate, representing a physical barrier to the growth of symbiont fungus.

Background interference on the color of dental composite materials with different thickness by digital contrast

In this work the color dependence of resin composites with the background color was evaluated. The objective was to measure since what thickness the color of the sample stops being influenced by the color of the background over which the resin is placed and the methodology used in experiment was based in analyzing the contrast of digital images of the sample over a black background. The results shown that since 0.8 mm the images contrast becomes almost constant; it prove that since this thickness the color of resin composite depends on the optical resin properties only. The experiment was repeated under three conditions of luminosity to evaluate the influence of it on the image contrast and the results obtained were identical.

Plasmonic structures fabricated by interference lithography for sensor applications

In this work we demonstrate the use of holographic lithography for generation of large area plasmonic periodic structures. Submicrometric array of holes, with different periods and thickness, were recorded in gold films, in areas of about 1 cm2, with homogeneity similar to that of samples recorded by Focused Ion Beam. In order to check the plasmonic properties, we measured the transmission spectra of the samples. The spectra exhibit the typical surface plasmon resonances (SPR) in the infrared whose position and width present the expected behavior with the period of the array and film thickness. The shift of the peak position with the permittivity of the surrounding medium demonstrates the feasebility of the sample as large area sensors. © 2009 SPIE.

Bandgap voltage reference with low susceptibility to electromagnetic interference (EMI)

In this paper, the susceptibility of a current-mode bandgap voltage reference to electromagnetic interference (EMI) superimposed to the power supply is investigated by simulation. Designed for AMS 0.35 CMOS process, the circuit provides a stable voltage reference in the temperature range of -40-150°C. When EMI disturbances are present, the circuit exhibits only 6.7 mV of offset for interfering signals in the frequency range of 150 kHz-1 GHz. © 2011 ACM.

Evaluation of sample preparation procedures and krypton as an interference standard probe for arsenic speciation by HPLC-ICP-QMS

Different conditions of extraction using water, a methanol-water mixture and nitric acid solutions were evaluated for speciation of As(iii), As(v), DMA and MMA in plant samples that previously received As(v) after being sown and emergence was investigated. Microwave-assisted extraction (MAE) using diluted nitric acid solutions was also performed for arsenic extraction from chicken feed samples. The separation and determination of arsenic species were performed using HPLC-ICP-MS. The interference standard method (IFS) using 83Kr+ as the IFS probe was employed to minimize spectral interferences caused by polyatomic species, such as 40Ar 35Cl+. The extraction procedures tested presented adequate extraction efficiencies (90%), and the four arsenic species evaluated were found in plant samples. Extractions with diluted nitric acid solution at 90 °C were the most efficient strategy, with quantitative recoveries for all four As species in plant tissues. On the other hand, the methanol-water mixture was the solvent with the lowest extraction efficiency (50-60%). For chicken feed samples, MAE at 100 °C for 30 min resulted in an extraction efficiency of 97% and only As(v) was found, without any species interconversion. The IFS method contributed to improving precision and limits of detection and quantification for all tested extraction procedures. Significant improvements on accuracy were obtained by applying the IFS method and recoveries between 77 and 94%, and 82 and 93% were obtained for plant extracts and chicken feed samples, respectively. This journal is © 2013 The Royal Society of Chemistry.

Flexible magnetic membranes based on bacterial cellulose and its evaluation as electromagnetic interference shielding material

Flexible magnetic membranes with high proportion of magnetite were successfully prepared by previous impregnation of the never dried bacterial cellulose pellicles with ferric chloride followed by reduction with sodium bisulfite and alkaline treatment for magnetite precipitation. Membranes were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating magnetometer, field emission scanning electron microscopy (FEG-SEM) and impedance spectroscopy. Microwave properties of these membranes were investigated in the X-band (8.2 to 12.4 GHz). FEG-SEM micrographs show an effective coverage of the BC nanofibers by Fe 3O4 nanoparticles. Membranes with up to 75% in weight of particles have been prepared after 60 min of reaction. Magnetite nanoparticles in the form of aggregates well adhered to the BC fibers were observed by SEM. The average crystal sizes of the magnetic particles were in the range of 10 ± 1 to 13 ± 1 nm (estimated by XRD). The magnetic particles in the BC pellicles presented superparamagnetic behavior with a saturation magnetization in the range of 60 emu g- 1 and coercive force around 15 Oe. These magnetic pellicles also displayed high electrical permittivity and a potential application as microwave absorber materials. © 2013 Elsevier B.V.

Interference of cage fish farm on diet, condition factor and numeric abundance on wild fish in a Neotropical reservoir

Historically, the ichthyofauna of large Brazilian rivers has been subject to anthropogenic interference, such as impoundments. Currently, cage fish farming systems are a new source of impact on aquatic ecosystems. The objective of this study was to characterise the impact of freshwater fish farms on the feeding of five species of Neotropical freshwater fish. Specimens of Astyanax altiparanae, Galeocharax knerii, Iheringicthys labrosus, Pimelodus maculatus and Plagioscion squamosissimus were sampled in areas around two systems of cage fish farming (CF), and two control areas (CT) that were not influenced by this activity. Results show that there were significant changes in the diet of trophic generalist species (A. altiparanae, P. maculatus and I. labrosus) accompanied by a related increase in the condition factor values of these species in cage areas. Trophic specialist species, such as the carnivorous fish species G. knerii and P. squamosissimus, presented small differences between the CF and CT areas with regard to diet and showed no differences in other analyses performed. In conclusion, cage fish farms can affect the natural diet of trophic generalist fish species, directly affecting the nutritional status (condition factor), where food wastes was found to be one of the principal items consumed by this trophic guild. Results indicate that these species are responsible for recycling a great quantity of organic matter transferred by this type of activity, which, along with local fishery activities, contribute to mitigation of associated processes of eutrophication. © 2013 Elsevier B.V.

Interference of Vaccinal Antibodies on Serological Diagnostic of Leptospirosis in Vaccinated Buffalo using Two Types of Commercial Vaccines

The vaccinal antibodies interference represents one of the problems in the leptospirosis diagnostic on serum. The present study aimed to determine the pattern of serum agglutinins anti-Leptospirae spp in vaccinated female buffaloes against leptospirosis using two types of commercial vaccines: bacterin and extern membrane. The temporal interference of vaccinal titers on serum diagnostic was evaluated. Three groups of 11 adult female buffaloes were established as follows: G1 control, non-vaccinated; G2: vaccinated with bacterin containing six serovars and G3 with extern membrane vaccine containing five serovars. A booster was administered at 30 days from the first vaccination (dfv) and two re- vaccinations were performed in each semester (days 210 and 390). Serum samples were collected on days 0, 15, 30, 45 and 60 and every 30 days until 540 dfv, being submitted to Serum Agglutination Microscopy (SAM) against the serovars present in the vaccine. G1 remained always negative. Both vaccines induced serologic responses when assessed by SAM at 150 days post first vaccination against all serovars and they revealed maximum titers around days 45 and 60 after first vaccination. At the re-vaccination there was an increase on agglutinin levels, but of less intensity than the levels previously observed. After six months from the second revaccination (540 dfv), they were almost zero, which demonstrates the short duration of diagnostic interference. The serologic monitoring of the vaccinated herds can be an efficient method to evaluate the status of protection provided by the vaccine.

Fano interference and a slight fluctuation of the Majorana hallmark

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Probing the antisymmetric Fano interference assisted by a Majorana fermion

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)