Estructura y flexibilidad en los sistemas de clasificación de documentación: una propuesta para América Latina = Structure and flexibility in classification schemes for documentation: a proposal for Latin America

Incluye Bibliografía

Promoting economic links between the integration schemes of Latin America and the Caribbean

Includes bibliography

Criando novos tabuleiros para o jogo Tri-Hex e sua validação didático-pedagógica na formação continuada de professores de matemática: uma contribuição para a geometria das séries finais do ensino fundamental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Promoting economic links between the integration schemes of Latin America and the Caribbean: a CARICOM perspective on selected issues

Includes bibliography

How do driver compensation schemes affect bus system performance?: a comparison between fixed wage and "guerra por el boleto" in Santiago, Chile.

Two systems of bus driver compensation exist in Santiago, Chile. The majority of drivers are paid per passenger transported, which leads to drivers trying to maximize the number of passengers each one conveys. Some of these effects are beneficial, such as a more active effort to minimize the problem of bus bunching, while others, such as aggressive driving, can be harmful. Drivers are said to "race" and the term "War for the Fare" is commonly used. Drivers also pay freelance workers called "sapos" to provide spacing information. Similar phenomena occur in other Latin American capitals.The other system, a fixed wage, is used by 2 companies holding recently awarded concessions for routes feeding metro stations.This paper discusses, quantitatively and qualitatively, the effects of these two compensation systems on accidents, quality of service, attitudes of both users and drivers, and average waiting times for passengers.

Historic of therapeutic efficacy of albendazol sulphoxide administered in different routes, dosages and treatment schemes, against Taenia saginata in cattle experimentally infected

The present study aimed to notify the history of albendazole sulphoxide (ALB-SO) and albendazole (ALBZ) efficacy against Taenia saginata cysticercus (Cysticercus bovis) parasitizing experimentally infected bovines. A total of 11 efficacy trials were performed between the years of 2002 and 2010. In order to perform these trials, animals were individually inoculated with 2 x 104 eggs of T. saginata in each study's day zero (DO). For every trial, a positive control group (untreated infected animals) and a negative control group (animals that were neither infected nor treated) were used. ALB-SO or ALB were administered in the different dosages, in different days of treatments. In a last study with this formulation, this active principle was administered orally, mixed with the mineral supplement, on the 60th DPI, in a dosage of 30 mg/kg. In all trials, on the 100th DPI, all animals were euthanized and submitted to the sequenced slicing of 26 anatomical segments (fragments of approximately five millimeters) for the survey of T. saginata cysticercus. With the obtained results it is possible to verify that in the first trials, conducted in 2002, ALB-SO reached, independently of dosage and treatment scheme, efficacies superior to 98% (arithmetic means). The trials conducted in 2005 (2.5 mg/kg on the 30th, 60th, and 90th DPI) obtained values of efficacy all inferior to 60%. In 2008, the trials with 2.5 and 7.7 mg/kg demonstrated efficacy values inferior to 40%, for both dosages and treatment schemes (30th/60th/90th DPI and 60th DPI). When this formulation was administered orally on the dosage of 30 mg/kg on the 60th DPI, the efficacy against T. saginata cysticercus reached 88.28%. ALB administered orally showed efficacy values of 0.0%, 29.88% and 28.64% in the dosages of 5, 10 and 15 mg/kg, respectively, using the treatment schemes described above for each dosage. Based on the results of these trials, conducted in an eight year period (2002-2010) using the sequenced slicing method for evaluating the efficacy of the aforementioned formulations against T. saginata cysticercus, it is possible to observe that, amongst the few molecules used in the chemotherapic treatment against T. saginata larvae, ALB-SO, administered in varied routes, dosages and treatment schemes, the studies conducted in 2008, 2009, and 2010, have a low therapeutic efficacy against C bovis in Brazil, while ALBZ had insignificant efficacy values against T. saginata larvae parasitizing experimentally infected bovines. However, future studies using molecular biology will be necessary to assess whether the difference on the efficacy of the ALB-SO can be related to strain or another specific factor. (C) 2013 Elsevier Inc. All rights reserved.

Axial loads on implant-supported partial fixed prostheses for external and internal hex connections and machined and plastic copings: strain gauge analysis

The aim of this in vitro study was to use strain gauge (SG) analysis to compare the effects of the implant-abutment joint, the coping, and the location of load on strain distribution in the bone around implants supporting 3-unit fixed partial prostheses. Three external hexagon (EH) implants and 3 internal hexagon (IH) implants were inserted into 2 polyurethane blocks. Microunit abutments were screwed onto their respective implant groups. Machined cobalt-chromium copings and plastic copings were screwed onto the abutments, which received standard wax patterns. The wax patterns were cast in a cobalt-chromium alloy (n = 5): group 1 = EH/machined. group 2 = EH/plastic, group 3 = IH/machined, and group 4 = IH/plastic. Four SGs were bonded onto the surface of the block tangentially to the implants. Each metallic structure was screwed onto the abutments and an axial load of 30 kg was applied at 5 predetermined points. The magnitude of microstrain on each SG was recorded in units of microstrain (mu epsilon). The data were analyzed using 3-factor repeated measures analysis of variance and a Tukey test (alpha = 0.05). The results showed statistically significant differences for the type of implant-abutment joint, loading point, and interaction at the implant-abutment joint/loading point. The IH connection showed higher microstrain values than the EH connection. It was concluded that the type of coping did not interfere in the magnitude of microstrain, but the implant/abutment joint and axial loading location influenced this magnitude.

Stability analysis of Crank-Nicolson and Euler schemes for time-dependent diffusion equations

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

Effects of Haematobia irritans infestation on weight gain of Nelore calves assessed with different antiparasitic treatment schemes

Effects of Haematobia irritans infestation on weight gain of 18 to 20 months old non-castrated Nelore calves, were investigated, under field conditions, using different antiparasitic treatments. Sixty animals were divided in three groups, with 20 bovines each: T01 (untreated control); T02 (treated with Cypermethrin 15 g + Chlorpyriphos 25 g + Citronellal 1 g, as a whole body spray, on days 0,30, 60, 90 and 120 post-treatment); and T03 (treated on day zero with an ear tag impregnated with Diazinon 6 g on the left ear). Counts of H. irritans were conducted on day 30, 60, 90, 120 and 150 post-treatment (DPT). On the same experimental dates, animals were individually weighed, seeking to evaluate the effects of parasitism on the development of animals in each group. From this study it is concluded that T03 had significantly higher efficacy (>90%, till 90 DPT), based on H. irritans fly counts, compared to T02 which showed little or no effect. At the specific conditions of the present study, an average of approximately 90 flies (mean difference of flycounts between groups T01 and T03) was associated with a difference of 20 kg/animal in 150 days. (C) 2014 Elsevier B.V. All rights reserved.

Variational and perturbative schemes for a spiked harmonic oscillator

A variational analysis of the spiked harmonic oscillator Hamiltonian operator - d2/dx2 + x2 + l(l + 1)/x2 + λ|x| -α, where α is a real positive parameter, is reported in this work. The formalism makes use of the functional space spanned by the solutions of the Schrödinger equation for the linear harmonic oscillator Hamiltonian supplemented by a Dirichlet boundary condition, and a standard procedure for diagonalizing symmetric matrices. The eigenvalues obtained by increasing the dimension of the basis set provide accurate approximations for the ground state energy of the model system, valid for positive and relatively large values of the coupling parameter λ. Additionally, a large coupling perturbative expansion is carried out and the contributions up to fourth-order to the ground state energy are explicitly evaluated. Numerical results are compared for the special case α = 5/2. © 1989 American Institute of Physics.

Centralized vs. Distributed Connection Management Schemes under Different Traffic Patterns in Wavelength-Convertible Optical Networks

Centralized and Distributed methods are two connection management schemes in wavelength convertible optical networks. In the earlier work, the centralized scheme is said to have lower network blocking probability than the distributed one. Hence, much of the previous work in connection management has focused on the comparison of different algorithms in only distributed scheme or in only centralized scheme. However, we believe that the network blocking probability of these two connection management schemes depends, to a great extent, on the network traffic patterns and reservation times. Our simulation results reveal that the performance improvement (in terms of blocking probability) of centralized method over distributed method is inversely proportional to the ratio of average connection interarrival time to reservation time. After that ratio increases beyond a threshold, those two connection management schemes yield almost the same blocking probability under the same network load. In this paper, we review the working procedure of distributed and centralized schemes, discuss the tradeoff between them, compare these two methods under different network traffic patterns via simulation and give our conclusion based on the simulation data.

Group Rekeying Schemes for Secure Group Communication in Wireless Sensor Networks

Wireless sensor networks are promising solutions for many applications. However, wireless sensor nodes suffer from many constraints such as low computation capability, small memory, limited energy resources, and so on. Grouping is an important technique to localize computation and reduce communication overhead in wireless sensor networks. In this paper, we use grouping to refer to the process of combining a set of sensor nodes with similar properties. We propose two centralized group rekeying (CGK) schemes for secure group communication in sensor networks. The lifetime of a group is divided into three phases, i.e., group formation, group maintenance, and group dissolution. We demonstrate how to set up the group and establish the group key in each phase. Our analysis shows that the proposed two schemes are computationally efficient and secure.

Rerouting Schemes for Dynamic Traffic Grooming in Optical WDM Mesh Networks

Traffic grooming in optical WDM mesh networks is a two-layer routing problem to effectively pack low-rate connections onto high-rate lightpaths, which, in turn, are established on wavelength links. In this work, we employ the rerouting approach to improve the network throughput under the dynamic traffic model. We propose two rerouting schemes, rerouting at lightpath level (RRAL) and rerouting at connection level (RRAC). A qualitative comparison is made between RRAL and RRAC. We also propose the critical-wavelength-avoiding one-lightpath-limited (CWA-1L) and critical-lightpath-avoiding one-connection-limited (CLA-1C) rerouting heuristics, which are based on the two rerouting schemes respectively. Simulation results show that rerouting reduces the connection blocking probability significantly.

The Poisson-exponential regression model under different latent activation schemes

In this paper, a new family of survival distributions is presented. It is derived by considering that the latent number of failure causes follows a Poisson distribution and the time for these causes to be activated follows an exponential distribution. Three different activation schemes are also considered. Moreover, we propose the inclusion of covariates in the model formulation in order to study their effect on the expected value of the number of causes and on the failure rate function. Inferential procedure based on the maximum likelihood method is discussed and evaluated via simulation. The developed methodology is illustrated on a real data set on ovarian cancer.

Influence of different resistance exercise loading schemes on mechanical power output in work to rest ratio - equated and - nonequated conditions

Paulo CA, Roschel H, Ugrinowitsch C, Kobal R and Tricoli V. Influence of different resistance exercise loading schemes on mechanical power output in work to rest ratio-equated and -nonequated conditions. J Strength Cond Res 26(5): 1308-1312, 2012-It is well known that most sports are characterized by the performance of intermittent high-intensity actions, requiring high muscle power production within different intervals. In fact, the manipulation of the exercise to rest ratio in muscle power training programs may constitute an interesting strategy when considering the specific performance demand of a given sport modality. Thus, the aim of this study was to evaluate the influence of different schemes of rest intervals and number of repetitions per set on muscle power production in the squat exercise between exercise to rest ratio-equated and -nonequated conditions. Nineteen young males (age: 25.7 +/- 4.4 years; weight: 81.3 +/- 13.7 kg; height: 178.1 +/- 5.5 cm) were randomly submitted to 3 different resistance exercise loading schemes, as follows: short-set short-interval condition (SSSI; 12 sets of 3 repetitions with a 27.3-second interval between sets); short-set long-interval condition (SSLI; 12 sets of 3 repetitions with a 60-second interval between sets); long-set long-interval (LSLI; 6 sets of 6 repetitions with a 60-second rest interval between sets). The main finding of the present study is that the lower exercise to rest ratio protocol (SSLI) resulted in greater average power production (601.88 +/- 142.48 W) when compared with both SSSI and LSLI (581.86 +/- 113.18 W; 578 +/- 138.78 W, respectively). Additionally, both the exercise to rest ratio-equated conditions presented similar performance and metabolic results. In summary, these findings suggest that shorter rest intervals may fully restore the individual's ability to produce muscle power if a smaller exercise volume per set is performed and that lower exercise to rest ratio protocols result in greater average power production when compared with higher ratio ones.