Determination of the force systems produced by different configurations of tear drop orthodontic loops

Objective: To determine the mechanical characteristics of teardrop loop with and without helix fabricated using different metal alloy compositions (stainless steel and beta-titanium), submitted to different intensities of bends preactivation (0° and 40°), and with different cross-sectional dimension of the wire used to build these loops (0.017 x 0.025-in and 0.019 x 0.025-in). Methods: Eighty loops used to close spaces were submitted to mechanical tests. The magnitudes of horizontal force, the moment/force ratio, and the load/deflection ratio produced by the specimens were quantified. Loops were submitted to a total activation of 5.0 mm and the values were registered for each 1.0 mm of activation. For statistic data analysis, a analysis of variance was performed and a Tukey's Multiple Comparison test was used as supplement, considering a 5% level of significance. Results: In general, teardrop loops with helix produced lower magnitudes of horizontal force and load/deflection ratio, and higher moment/force ratio than teardrop loops without helix. Among all analyzed variables, metal alloy composition presented greater influence in the horizontal force and in the load/deflection ratio. The moment/force ratio showed to be more influenced by the preactivation of loops for space closure. © 2013 Dental Press Journal of Orthodontics.

Orthodontic force increases interleukin-1β and tumor necrosis factor-α expression and alveolar bone loss in periodontitis

Background: The present study aims to evaluate the effects of orthodontic movement (OM) on the periodontal tissues of rats with ligature-induced periodontal disease. Methods: Eighty-eight rats were divided into four groups: 1) negative control (sham operated); 2) periodontal disease; 3) OM; and 4) periodontal disease followed by OM (OMP). Rats were sacrificed 3 hours or 1, 3, or 7 days after OM commencement. Bone volume fraction (BVF) and bone mineral density (BMD) were assessed in hemimaxillae by microcomputed tomography analysis. Expression of the proinflammatory cytokines interleukin (IL)-1β and tumor necrosis factor (TNF)-α were evaluated in gingival samples by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, and in the furcation region by immunohistochemistry analysis (IHC). Results: The OMP group had lower BVF and BMD levels compared to the other groups at day 7 (P <0.05). Maximum messenger ribonucleic acid expression of both cytokines was observed in the OMP group at day 1 (P <0.05). In the same period, all proteins were expressed in high levels for all test groups compared to the control group. The number of cells positive for IL-1β and TNF-α by IHC was highest in the OMP group at day 1, with progressive reduction thereafter. Conclusion: The results suggest that OM acts synergistically with periodontal disease in periodontal breakdown through upregulation of proinflammatory cytokines.

Resistance training for explosive and maximal strength: Effects on early and late rate of force development

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

Report of the special task force on collaboration in agricultural research

Presenta recomendaciones para establecer un criterio de colaboracion entre las agencias que operan en la region en el ambito de la investigacion agricola.

Comparison of the preferential margins in the ECCM tariff with the average margins prior in force in the region

Includes bibliography

People and workers in Latin America: simulation experiments with population and the labour force in selected countries

Includes bibliography

Development strategy implications of population growth and labour force absorption in Latin America

Includes bibliography

Participación de la juventud en el desarrollo de América Latina: problemas y políticas relativos a su inserción en la fuerza de trabajo y a sus posibilidades de educación y empleo = Participation of youth in the development process of Latin America: problems and policies regarding labour force insertion, education and employment opportunities

Incluye Bibliografía

Port Security Measures: One Year after the Entry into Force of the International Ship and Port Facility Security Code (ISPS Code)

New Page 1This issue of the FALBulletin presents information relating to the implementation in Latin Americanand Caribbean countries of the International Ship and Port Facility SecurityCode (ISPS Code) of the International Maritime Organization (OMI), one yearafter its entry into force on 1 July 2004. Information is included on the charges associated with the securitymeasures, in the world and in Latin America, together with an analysis ofcompliance with the measures in a group of countries from the Southern Cone ofthe region. 

Regional report on measuring disability: Overview of the disability measurement procedures in Latin America and the Caribbean. Task Force on Disability Measurement Statistical Conference of the Americas (SCA)

Introduction .-- I. Inclusion of international guidelines in disability measurement processes in Latin American and Caribbean countries .-- II. State of the art in disability measurement in the region’s countries .-- III. Main difficulties facing countries in terms of collecting information .-- Conclusions.

Influence of ovariectomy combined with lack of masticatory force in the evolution of periodontal disease

AIM: To evaluate the influence of ovariectomy combined with lack of masticatory force in the evolution of periodontal disease induced in rats.METHODS: Forty rats were bilaterally ovariectomized and 40 were submitted to sham ovariectomy. Periodontal disease was induced in the mandibular left first molar and the maxillary left first molar was extracted from half of the rats. The rats were randomly euthanized at 3, 7, 14 and 30 days post periodontal disease induction. Serial sections were obtained from the furcation area and stained for histological and histomorphometric analysis. The results of the histomorphometric analysis were statistically analyzed by ANOVA and Tukey tests.RESULTS: The results demonstrated statistically significant differences in the percentage of bone tissue when the variables presence or absence of estrogen (p=0.020) and time of euthanasia (p=0.002) were evaluated. However, the extraction procedure did not significantly affect the percentage of bone tissue (p=0.598).CONCLUSIONS : The bone loss resulting from periodontal disease is increased by estrogen deficiency and varies according to the time course of periodontitis. In contrast, masticatory force does not seem to interfere in bone loss derived from periodontal disease.

Visuomotor processing and hand force coordination in dyslexic children during a visually guided manipulation task

Developmental Dyslexia negatively affects children's reading and writing ability and, in most cases, performance in sensorimotor tasks. These deficits have been associated with structural and functional alterations in the cerebellum and the posterior parietal cortex (PPC). Both neural structures are active during visually guided force control and in the coordination of load force (LF) and grip force (GF) during manipulation tasks. Surprisingly, both phenomena have not been investigated in dyslexic children. Therefore, the aim of this study was to compare dyslexic and non-dyslexic children regarding their visuomotor processing ability and GF-LF coordination during a static manipulation task. Thirteen dyslexic (8-14YO) and 13 age- and sex-matched non-dyslexic (control) children participated in the study. They were asked to grasp a fixed instrumented handle using the tip of all digits and pull the handle upward exerting isometric force to match a ramp-and-hold force profile displayed in a computer monitor. Task performance (i.e., visuomotor coordination) was assessed by RMSE calculated in both ramp and hold phases. GF-LF coordination was assessed by the ratio between GF and LF (GF/LF) calculated at both phases and the maximum value of a cross-correlation function (r(max)) and its respective time lag calculated at ramp phase. The results revealed that the RMSE at both phases was larger in dyslexic than in control children. However, we found that GF/LF, rmax, and time lags were similar between groups. Those findings indicate that dyslexic children have a mild deficit in visuomotor processing but preserved GF-LF coordination. Altogether, these findings suggested that dyslexic children could present mild structural and functional alterations in specific PPC or cerebellum areas that are directly related to visuomotor processing. (C) 2014 Elsevier Ltd. All rights reserved.

Greening the work force in Brazilian hotels: The role of environmental training

BACKGROUND: Organizations are increasingly required to reduce their environmental impact through the adoption of environmental management, which requires the support of human resource practices.OBJECTIVE: The objective of this study is to determine whether human resource management practices, especially training, are supporting environmental management practices at four hotels located in Brazil.METHODS: This research is qualitative, based on the analysis of four hotels in Brazil.RESULTS: Based on the systematized empirical evidence collected from four hotels (Hotels A, B, C, and D), it can be concluded that: (1) human resource management is still not fully aligned with environmental objectives at the hotels studied; (2) only Hotel B has implemented environmental management practices and aligned with human resource management in a more developed manner, which may indicate that these two variables of analysis could have interrelations; (3) environmental training as a human resource management practice was verified in all hotels analyzed.CONCLUSIONS: The greening of human resources practices is not fully aligned with environmental objectives in the hotels studied. If these hotels really wish to "go green," environmental training will be necessary. Hotel stakeholders play a major role in implementing the greening of the hotel industry.