Seed removal by ants from faeces produced by different vertebrate species

Ants frequently harvest seeds from faeces of frugivorous vertebrates. By transporting these seeds to nests, ants may influence seed dispersal success of plants. Seed removal by ants from vertebrate faeces is influenced by the seed species involved. Faeces from different vertebrates differ in chemical composition and physical characteristics. It remains unclear, however, whether the faeces itself affects the ant-seed interaction. In this study experimental seed-containing faecal portions were prepared using defecations of birds, marsupials, and monkeys and seeds of two aroids (Philodendron corcovadense and P. ppendiculatum, Araceae) and one liana species (Schlegelia parviflora, Bignoniaceae). Faecal portions were arranged along a transect established in the understory of a lowland rainforest in southeast Brazil. For P. appendiculatum the probability of detection and the proportion of seeds removed were identical between marsupial and monkey faeces. For P. corcovadense and S. parviflora, the probability of detection was affected by seed species and, apparently, also by the interaction between seed species and type of faeces (P = 0.097), but not by the type of faeces itself (bird or monkey). Both factors (i.e., seed species and type of faeces) affected the proportion of seeds removed (faeces type was marginally significant; P = 0.08), whereas the interaction between them was not significant. The results indicate that seed species affects seed removal by ants, while the type of faeces probably interacts with seed traits to influence faeces detection.

Seed germination and removal of Michelia champaca L. (Magnoliaceae) in eucalypt stands: the influence of the aril

Testou-se o efeito do arilo na germinação de M. champaca em condições controladas, bem como na sua remoção, em ambiente natural. Os ensaios de germinação foram mantidos a 25 ± 2 °C, sob luz branca constante. Os experimentos de remoção foram levados a cabo em três talhões velhos (idades de 39 a 62 anos) e três novos (15 anos de idade) de eucalipto mantidos no Horto Florestal Navarro de Andrade, em Rio Claro, SP. Os resultados indicaram que o arilo inibe a germinação, sendo as sementes fotoblásticas positivas. Observou-se que a remoção de sementes foi maior em talhões velhos do que em novos, provavelmente devido à maior densidade de roedores nos talhões velhos. Nos talhões novos, verificou-se que formigas removiam mais sementes ariladas. Esses insetos são importantes agentes na remoção do arilo de sementes derrubadas por pássaros, promovendo, assim, aumento na germinação e evitando a possível predação das sementes por roedores.

Toward reliable estimates of seed removal by small mammals and birds in the Neotropics

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

Edge detection and noise removal by use of a partial differential equation with automatic selection of parameters

This work deals with noise removal by the use of an edge preserving method whose parameters are automatically estimated, for any application, by simply providing information about the standard deviation noise level we wish to eliminate. The desired noiseless image u(x), in a Partial Differential Equation based model, can be viewed as the solution of an evolutionary differential equation u t(x) = F(u xx, u x, u, x, t) which means that the true solution will be reached when t ® ¥. In practical applications we should stop the time ''t'' at some moment during this evolutionary process. This work presents a sufficient condition, related to time t and to the standard deviation s of the noise we desire to remove, which gives a constant T such that u(x, T) is a good approximation of u(x). The approach here focused on edge preservation during the noise elimination process as its main characteristic. The balance between edge points and interior points is carried out by a function g which depends on the initial noisy image u(x, t0), the standard deviation of the noise we want to eliminate and a constant k. The k parameter estimation is also presented in this work therefore making, the proposed model automatic. The model's feasibility and the choice of the optimal time scale is evident through out the various experimental results.

A Decomposition and Noise Removal Method Combining Diffusion Equation and Wave Atoms for Textured Images

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

Morphology and bacterial colonisation of tooth/ceramic restoration interface after different cement excess removal techniques

Objectives: To evaluate the influence of different protocols for resin cement removal during cementation on biofilm formation.Methods: Twenty-eight ceramic blocks, which were injected under pressure, were placed over enamel blocks obtained from freshly extracted bovine incisors. The ceramic blocks were cemented to the enamel blocks using a dual-cured resin cement and the excess resin was removed according to the experimental group: TS: Teflon spatula; BR: brush; BR+: brush and polishing; SB+: scalpel blade and polishing. After autoclaving, the samples were colonised by incubation in a sucrose broth suspension standardised with Streptococcus mutans in microaerophilic stove. Specimens were quantitatively analysed for bacterial adherence at the adhesive interface using confocal laser scanning microscopy and counting the colony forming units, and qualitatively analysed using SEM. The roughness (Ra/Rz/RSm) was also analysed. Data were analysed by 1-way ANOVA and Tukey's test (5%).Results: The roughness values ranged from 0.96 to 1.69 mu m for Ra (p > 0.05), from 11.59 to 22.80 mu m for Rz (p = 0.02 < 0.05) and from 293.2 to 534.3 mu m for RSm (p = 0.00). Bacterial adhesion varied between 1,974,000 and 2,814,000 CFU/ml (p = 0.00). Biofilm mean thickness ranged from 0.477 and 0.556 mu m (p > 0.05), whilst the biovolume values were between 0.388 and 0.547 mu m(3)/mu m(2) (p = 0.04). Lower values for roughness, bacterial adhesion, biofilm thickness and biovolume were found with BR, whilst TS presented the highest values for most of the parameters. SEM images confirmed the quantitative values.Conclusions: The restoration margin morphology and interface roughness affects bacterial accumulation. The brush technique promoted less bacterial colonisation at the adhesive interface than did the other removal methods.Clinical significance: The brush technique seems to be a good option for removing the excess resin cement after adhesive cementation in clinical practice, as indicated by its better results with lower bacterial colonisation. (C) 2012 Elsevier Ltd. All rights reserved.

Dentine microhardness after different methods for detection and removal of carious dentine tissue

There are several methods for identifying carious dentinal tissue aiming to avoid removal of healthy dentinal tissue. Objectives: The purpose of this study was to test different methods for the detection of carious dentinal tissue regarding the amount of carious tissue removed and the remaining dentin microhardness after caries removal. Material and methods: The dentin surfaces of 20 bovine teeth were exposed and half of the surface was protected with nail polish. Cariogenic challenge was performed by immersion in a demineralizing solution for 14 days. After transverse cross-section of the crown, the specimens were divided into four groups (n=10), according to the method used to identify and remove the carious tissue: "Papacarie", Caries-detector dye, DIAGNOdent and Tactile method. After caries removal, the cross-sectional surface was included in acrylic resin and polished. In a microhardness tester, the removed dentin thickness and the Vickers microhardness of the following regions were evaluated: remaining dentin after caries removal and superficial and deep healthy dentin. Results: ANOVA and Tukey's test (alpha=0.05) were performed, except for DIAGNOdent, which did not detect the presence of caries. Results for removed dentin thickness were: "Papacarie" (424.7 +/- 105.0; a), Caries-detector dye (370.5 +/- 78.3; ab), Tactile method (322.8 +/- 51.5; bc). Results for the remaining dentin microhardness were: "Papacarie" (42.2 +/- 10.5; bc), Caries-detector dye (44.6 +/- 11.8; bc), Tactile method (24.3 +/- 9.0; d). Conclusions: DIAGNOdent did not detect the presence of carious tissue; Tactile method and "Papacarie" resulted in the least and the most dentinal thickness removal, respectively; Tactile method differed significantly from "Papacarie" and Caries-detector dye in terms of the remaining dentin microhardness, and Tactile method was the one which presented the lowest microhardness values.

Fresh-frozen human bone graft for repair of defect after adenomatoid odontogenic tumour removal

The aim of this paper was report the clinical, radiographic, and histological case of adenomatoid odontogenic tumour (AOT) in adolescent woman as well as present the reconstructive treatment of AOT using fresh-frozen human bone graft with guided bone regeneration. AOT is a benign, noninvasive lesion with slow but progressive growth. Biopsy and microscopic examination confirmed the presence of an AOT. Treatment was conservative and the prognosis was excellent. The patient has been followed-up for without recurrence. The use of fresh-frozen human bone graft can be a safe choice for reconstruction of the bone defects to treat AOT.

A Strain Gauge Analysis of Microstrain Induced by Various Splinting Methods and Acrylic Resin Types for Implant Impressions

Purpose: The aim of this study was to investigate the level of microstrain that is exerted during polymerization of acrylic resins used for splinting during implant impressions. Material and Methods: Two acrylic resins (GC Pattern Resin, Duralay II) and square transfer coping splinting methods were evaluated by means of strain gauge analysis. Two implants were embedded in a polyurethane block, and the abutments were positioned. Sixty specimens were prepared using two square transfer Copings that were rigidly connected to each other using the acrylic resins. The specimens were randomly divided into three groups of 20 each for the splinting methods: Method 1 was a one-piece method; in method 2, the splint was separated and reconnected after 17 minutes; and in method 3, the splint was separated and reconnected after 24 hours. In each group, half the specimens were splinted with GC Pattern Resin and the other half were splinted with Duralay II. Three microstrain measurements were performed by four strain gauges placed on the upper surface of the polyurethane blocks at 5 hours after resin polymerization for all groups. The data were analyzed statistically. Results: Both resin type and splinting method significantly affected microstrain. interaction terms were also significant. Method 1 in combination with Duralay II produced significantly higher microstrain (1,962.1 mu epsilon) than the other methods with this material (method 2: 241.1 mu epsilon; method 3: 181.5 mu epsilon). No significant difference was found between splinting methods in combination with GC Pattern Resin (method 1: 173.8 mu epsilon; method 2: 112.6 mu epsilon; method 3: 105.4 mu epsilon). Conclusions: Because of the high microstrain generated, Duralay II should not be used for one-piece acrylic resin splinting, and separation and reconnection are suggested. For GC Pattern Resin, variations in splinting methods did not significantly affect the microstrain created. Int J Oral Maxillofac Implants 2012;27:341-345

Machined and plastic copings in three-element prostheses with different types of implant-abutment joints: a strain gauge comparative analysis

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

Strain Gauge Analysis of the Effect of Porcelain Firing Simulation on the Prosthetic Misfit of Implant-Supported Frameworks

Objectives: This study investigated the effect of porcelain firing on the misfit of implant-supported frameworks and analyzed the influence of preheat treatment on the dimensional alterations.Materials and Methods: Four external-hex cylindrical implants were placed in polyurethane block. Ten frameworks of screw-retained implant-supported prostheses were cast in Pd-Ag using 2 procedures: (1) control group (CG, n = 5): cast in segments and laser welded; and test group (TG, n = 5): cast in segments, preheated, and laser welded. All samples were subjected to firing to simulate porcelain veneering firing. Strain gauges were bonded around the implants, and microstrain values (mu epsilon = 10(-6)epsilon) were recorded after welding (M1), oxidation cycle (M2), and glaze firing (M3). Data were statistically analyzed (2-way analysis of variance, Bonferroni, alpha = 0.05).Results: The microstrain value in the CG at M3 (475.2 mu epsilon) was significantly different from the values observed at M1 (355.6 mu epsilon) and M2 (413.9 mu epsilon). The values at M2 and M3 in the CG were not statistically different. Microstrain values recorded at different moments (M1: 361.6 mu epsilon/M2: 335.3 mu epsilon/M3: 307.2 mu epsilon) did not show significant difference.Conclusions: The framework misfit deteriorates during firing cycles of porcelain veneering. Metal distortion after porcelain veneering could be controlled by preheat treatment. (Implant Dent 2012;21:225-229)

Comparative Strain Gauge Analysis of External and Internal Hexagon, Morse Taper, and Influence of Straight and Offset Implant Configuration

Purpose: The present study was designed to analyze strain distributions caused by varying the fixture-abutment design and fixture alignment.Materials and Methods: Three implants of external, internal hexagon, and Morse taper were embedded in the center of each polyurethane block in straight placement and offset placement. Four strain gauges (SGs) were bonded on the surface of polyurethane block, which was designated SG1 placed mesially adjacent to implant A, SG2 and SG3 were placed mesially and distally adjacent to the implant B and SG4 was placed distally adjacent to the implant C. The 30 superstructures' occlusal screws were tightened onto the Microunit abutments with a torque of 10 N cm using the manufacturers' manual torque-controlling device.Results: There were statistically significant differences in prosthetic connection (P value = 0.0074 < 0.5). There were no statistically significant differences in placement configuration/alignment (P value = 0.7812 > 0.5).Conclusion: The results showed fundamental differences in both conditions. There was no evidence that there was any advantage to offset implant placement in reducing the strain around implants. The results also revealed that the internal hexagon and Morse taper joints did not reduce the microstrain around implants. (Implant Dent 2011; 20:e24-e32)

External Hexagon and Internal Hexagon in Straight and Offset Implant Placement: Strain Gauge Analysis

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

Straight and Offset Implant Placement under Axial and Nonaxial Loads in Implant-Supported Prostheses: Strain Gauge Analysis

Purpose: The aim of this in vitro study was to quantify strain development during axial and nonaxial loading using strain gauge analysis for three-element implant-supported FPDs, varying the arrangement of implants: straight line (L) and offset (O). Materials and Methods: Three Morse taper implants arranged in a straight line and three implants arranged in an offset configuration were inserted into two polyurethane blocks. Microunit abutments were screwed onto the implants, applying a 20 Ncm torque. Plastic copings were screwed onto the abutments, which received standard wax patterns cast in Co-Cr alloy (n = 10). Four strain gauges were bonded onto the surface of each block tangential to the implants. The occlusal screws of the superstructure were tightened onto microunit abutments using 10 Ncm and then axial and nonaxial loading of 30 Kg was applied for 10 seconds on the center of each implant and at 1 and 2 mm from the implants, totaling nine load application points. The microdeformations determined at the nine points were recorded by four strain gauges, and the same procedure was performed for all of the frameworks. Three loadings were made per load application point. The magnitude of microstrain on each strain gauge was recorded in units of microstrain (mu). The data were analyzed statistically by two-way ANOVA and Tukey's test (p < 0.05). Results: The configuration factor was statistically significant (p= 0.0004), but the load factor (p= 0.2420) and the interaction between the two factors were not significant (p= 0.5494). Tukey's test revealed differences between axial offset (mu) (183.2 +/- 93.64) and axial straight line (285.3 +/- 61.04) and differences between nonaxial 1 mm offset (201.0 +/- 50.24) and nonaxial 1 mm straight line (315.8 +/- 59.28). Conclusion: There was evidence that offset placement is capable of reducing the strain around an implant. In addition, the type of loading, axial force or nonaxial, did not have an influence until 2 mm.

Spectroscopic characterization of the reduction and removal of chromium (VI) by tropical peat and humin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)