INTERFERENCE BETWEEN SALMONELLA SEROTYPES IN INTESTINAL COLONIZATION OF CHICKENS - CORRELATION WITH IN-VITRO BEHAVIOR

The effect of colonisation of the alimentary tract of newly hatched chicks by different Salmonella serotypes on the establishment in the gut by other Salmonella strains inoculated afterwards was assessed. Although profound inhibition of colonisation had been found previously to be genus-specific, considerable variation was found within the Salmonella genus. Some strains were found to be much more inhibitory than others and some were more easily inhibited than were others. There was not an absolute relationship between inhibitory activity and colonisation ability. No relationship was seen between inhibition and serotype or phage types within serotypes. There was no correlation between in vivo inhibition and the extent of inhibition that occurred in early stationary phase cultures in rich, undefined broth cultures.

Arsenic as internal standard to correct for interferences in the determination of antimony by hydride generation in situ trapping graphite furnace atomic absorption spectrometry

The feasibility of using internal standardization (IS) to correct for interferences in hydride generation with in situ trapping in graphite furnace was evaluated. Arsenic was chosen as internal standard for Sb determination and Ir was used as permanent modifier. Fluctuations in the main parameters that affect the analytical results were minimized by IS and an effective contribution was verified in the studies of liquid phase interferences. Cobalt and Ni2+ were selected to illustrate the potential use of IS on the correction of interference by transition metals. The application of IS allows the Sb determination in samples containing up to 20-fold higher concentration of the Co2+ and Ni2+ when compared to the procedure without IS. The relative standard deviation of measurements varied from 0.3% to 0.7% and from 1.1% to 3.2% with and without IS, respectively. Recoveries within 92% and 107% of spiked aqueous solution containing Sb(III) and Sb(V) were found. (c) 2005 Elsevier B.V. All rights reserved.

Effect of Hydrogen Peroxide at 35% on the Morphology of Enamel and Interference in the De-remineralization Process: An In Situ Study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interference of high-heeled shoes in static balance among young women

The aim of the present study was to assess the effect of the use of high-heeled shoes on static balance in young adult women. Fifty-three women between 18 and 30 years of age and accustomed to wearing high-heeled shoes participated in the study. None of the participants had any orthopedic or neurologic alterations. Static balance was assessed using a force plate. Oscillations from the center of pressure in the mediolateral and anteroposterior directions were measured both when barefoot and when wearing high-heeled shoes [7 centimeters (cm) in height and 1 cm in diameter] under the conditions of eyes open and eyes closed. Two-way analysis of variance was employed for the statistical analysis, with the level of significance set at 5% (p < .05). The results revealed statistically significant differences between tests when barefoot and when wearing high-heeled shoes as well as with eyes open and eyes closed (p < .01). With the use of high-heeled shoes, there was a significant increase in mediolateral oscillation with eyes closed (p < .01). The present study demonstrates that the use of seven-cm high heels altered static balance in the healthy young women analyzed, increasing the oscillation of the center of pressure, regardless of visual restriction. (C) 2012 Elsevier B.V. All rights reserved.

The Araguaia fold belt, Brazil: A reactivated Brasiliano-Pan-African cycle (550 Ma) geosuture

The Araguaia-Tocantins geosuture, which separates the Araguaia Fold Belt (AFB) from the Archean Amazonian Craton, was active in the late Middle Proterozoic. The Baixo Araguaia Supergroup was deposited, consisting of the Estrondo Group (lower quartzites with intercalated schists), Xambioá Formation (schists), and Canto da Vazante Formation (upper feldspathic schists); and the Tocantins Group consisting of the Couto Magalhaës Formation (phyllites, quartzites, slates, limestones, and metacherts) and Pequizeiro Formation (upper chlorite schists); and associated mafic-ultramafic bodies. The deformational history includes four regional phases of deformation within this supracrustal sequence: recumbent folds with vergence to the west; refolding with a N-S trend; an intense crenulation episode; and late thrusting from east to west. Metamorphism is of intermediate or intermediate-high pressure type with garnet, biotite, chlorite, and sericite isograds succeeded by a slightly or non-metamorphosed zone, from east to west. Rocks surrounding sparse gneissic-cored domes contain isograds of staurolite, kyanite, and fibrolite. These isograds are believed to be associated with the 1100 Ma Uruaçuano event. The Brasiliano Orogeny strongly affected the AFB with displacements due to transcurrent reactivation of great and old faults of the basement, slight folding in the supracrustal sequence, intrusion of small granite bodies, and development of domes with associated normal faults. The area underlain by the Estrondo Group was uplifted at this time, causing the deposition of the Rio das Barreiras polymictic conglomerate of the central area. K-Ar and Rb-Sr analyses date this thermo-tectonic event at 550 ± 100 Ma. The Archean basement is exposed in the cores of domes as a granite-gneiss association, the Colméia complex, which shows thermo-tectonic features that may be interpreted as polycyclic imprints (Jequié, Transamazonian?, Uruaçuano, and Brasiliano Events). © 1989.

Weed-soybean interference studies in Brazil

Recently, a notable shift in weed patterns has occurred in some soybean growing regions, as a result of tillage system change and herbicide use. The weed communities are very diversified and strongly interfere with soybean growth and productivity, especially when the shading of superior leaves of the canopy occurs. Some changes to certain agricultural practices, such as cultivars, row spacing and sowing density, were studied and were considered suitable for the establishment of an integrated weed management system under Brazilian conditions. -from Author

Interference competition between ants (Hymenoptera: Formicidae) in Amazonian clearings

The first case of interference competition through soil dumping in South America is documented between Ectatomma quadridens and Pheidole fallax in Amazonian forest clearings. Workers of the diurnally active E. quadridens arrive at nests of P. fallax at dawn, and begin to fill up nest entrances with soil. During the day, E. quadridens workers remain stationary on the closed nest of P. fallax, and fill soil at the first signs of nest openings. Colonies of P. fallax distant from E. quadridens nests are active for 24 hrs; those near E. quadridens nests are limited for foraging nocturnally after opening nest entrances. This pattern was not found between heterospecific colonies at greater distances from the camp midden, according with the prediction that interference competition is more probable as resources become more concentrated. Colonies of P. fallax near E. quadridens nests located near the camp midden had a net forage intake of 60% of those located in areas without E. quadridens. -Author

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.

Laryngeal electromyography: Contribution to vocal fold immobility diagnosis

Laryngeal Electromyography (LEMG) is a diagnostic test commonly used in patients with vocal fold movement disorder The aim of this study is to describe LEMG in patients with vocalfold immobility. A total of 55 dysphonic patients with vocal fold immobility diagnosed by laryngeal endoscopy were grouped according to probable clinical cause: 1) unknown; 2) traumatic; or 3) tumoral compression. They were submitted to LEMG by percutaneous insertion of concentric needle electrode. LEMG was conclusive in all patients and showed a majority with peripheral nerve injury. LEMG diagnosed peripheral nerve damage in 25 group 1, 12 group 2, and 11 group 3 patients. LEMG was normal in 4 patients, suggesting cricoarytenoid joint fixation. Central nervous system disorders was suggested in 2 and myopathic pattern in 1. As the major cause of vocal fold immobility is peripheral nerve damage, LEMG is an important test to confirm diagnosis.