Three-dimensional reconstruction of fracture surfaces: Area matching algorithms for automatic parallax measurements

This paper describes two solutions for systematic measurement of surface elevation that can be used for both profile and surface reconstructions for quantitative fractography case studies. The first one is developed under Khoros graphical interface environment. It consists of an adaption of the almost classical area matching algorithm, that is based on cross-correlation operations, to the well-known method of parallax measurements from stereo pairs. A normalization function was created to avoid false cross-correlation peaks, driving to the true window best matching solution at each region analyzed on both stereo projections. Some limitations to the use of scanning electron microscopy and the types of surface patterns are also discussed. The second algorithm is based on a spatial correlation function. This solution is implemented under the NIH Image macro programming, combining a good representation for low contrast regions and many improvements on overall user interface and performance. Its advantages and limitations are also presented.

Power law distribution in education: University entrance examination

We studied the statistical distribution of candidate's performance which is measured through their marks in university entrance examination (Vestibular) of UNESP (Universidade Estadual Paulista) for years 1998, 1999, and 2000. All students are divided in three groups: Physical, Biological and Humanities. We paid special attention to the examination of Portuguese language which is common for all and examinations for the particular area. We observed long ubiquitous power law tails in Physical and Biological sciences. This indicate the presence of strong positive feedback in sciences. We are able to explain completely these statistical distributions through Gradually Truncated Power law distributions which we developed recently to explain statistical behavior of financial market. The statistical distribution in case of Portuguese language and humanities is close to normal distribution. We discuss the possible reason for this peculiar behavior.

Avaliação da resposta à quimioterapia primária em amostra de mulheres brasileiras com tumores de mama localmente avançados

PURPOSE: to evaluate the loco-regional response to primary chemotherapy in patients with breast cancer at stages II and III. METHODS: a retrospective and analytical clinical study carried out in 97 patients with an average age of 52.2 years old, with breast cancer at stages II and III, attended from January 1993 to December 2004, and submitted to 3 to 4 cycles of primary chemotherapy with 5-fl uorouracil - 500 mg/m2, epirubicin - 50 mg/m2 and cyclophosphamide - 500 mg/m2 or doxorubicin - 50 mg/m2 e cyclophosphamide - 500 mg/m2, and then to loco-regional surgical conservative or radical surgical treatment. Chi-square and Fisher's exact tests were used to study the association among the variables (age, menopausal state, pre-chemotherapy tumoral volume, axillary condition, stage, therapeutic scheme and number of cycles), while Pearson's correlation coefficient was used for the quantitative variables (tumoral volume according to the anatomo-pathological study and the post-chemotherapy clinical tumoral volume. The significance level was 5%. RESULTS: there were 56.8% of cases at stage II and 43.2% at stage III. Approximately 50% of the patients received FEC50 and 50% AC. Objective clinical response with primary chemotherapy was obtained in 64.9% of the cases. Full clinical response occurred in 12.3% of patients, while full pathological response occurred in 10.3% of the cases. CONCLUSIONS: there was a statistically significant correlation between the number of cycles and the response to primary chemotherapy. Patients who received 4 cycles had better response than those who received 3 cycles. There was also a statistically significant concordance between the evaluation through clinical examination of the response to primary chemotherapy and the pathological findings. No statistically significant correlation was observed concerning age, menopausal status, tumoral volume, and pretreatment of axillary damage.

Acurácia do teste de escada utilizando o consumo máximo de oxigênio como padrão-ouro

Objective: To determine the accuracy of the variables related to the fixed-height stair-climbing test (SCT) using maximal oxygen uptake (V̇O 2 max) as the gold standard. Methods: The SCT was performed on a staircase consisting of 6 flights (72 steps; 12.16 m total height), with verbal encouragement, in 51 patients. Stair-climbing time was measured, the variables 'work' and 'power' also being calculated. The V̇O2 max was measured using ergospirometry according to the Balke protocol. We calculated the Pearson linear correlation (r), as well as the values of p, between the SCT variables and V̇O2 max. To determine accuracy, the V̇O 2 max cut-off point was set at 25 mL/kg/min, and individuals were classified as normal or altered. The cut-off points for the SCT variables were determined using the receiver operating characteristic curve. The Kappa statistic (k) was used in order to assess concordance. Results: The following values were obtained for the variable 'time': cut-off point = 40 s; mean = 41 ± 15.5 s; r = -0.707; p < 0.005; specificity = 89%; sensibility = 83%; accuracy = 86%; and k = 0.724. For 'power', the values obtained were as follows: cut-off point = 200 w; mean = 222.3 ± 95.2 w; r = 0.515; p < 0.005; specificity = 67%; sensibility= 75%; accuracy = 71%; and k = 0.414. Since the correlation between the variable 'work' and V̇O2 max was not significant, that variable was discarded. Conclusion: Of the SCT variables tested, using V̇O2 max as the gold standard, the variable 'time' was the most accurate.

Early impairment of cognitive functions in Parkinson's disease

Background: Impairment in non-motor functions such as disturbances of some executive functions are also common events in Parkinson's disease patients. Objective: To verify the performance of Parkinson's disease patients in activities requiring visuoconstructive and visuospatial skills. Method: Thirty elderly patients with mild or moderate stages of Parkinson's disease were studied. The assessment of the clinical condition was based on the unified Parkinson's disease rating scale (56.28; SD=33.48), Hoehn and Yahr (2.2; SD=0.83), Schwab and England (78.93%), clock drawing test (7.36; SD=2.51), and mini-mental state examination (26.48; SD=10.11). Pearson's correlation and stepwise multiple regression were used for statistical analyses. Results: The patients presented deterioration in visuospatial and visuoconstructive skills. Conclusion: The clock drawing test proved to be a useful predictive tool for identifying early cognitive impairment in these individuals.

Síntomas depresivos y trastorno motor en pacientes con enfermedad de Parkinson

Introduction. Complex relations between brain and psychopathology have attracted the interest of researchers, aiming to clarify the neurobiological mechanisms of depression in Parkinson's disease, obviously in addiction to mental features. Aims. The association of motor impairment and decline of personal autonomy with severity of depressive symptoms was the hypothesis of the present study. Aiming to check this hypothesis, the objective of this study consisted in investigating relationships between the severity of depressive symptoms and motor characteristics of Parkinson's disease. Patients and methods. Thirty patients (53 to 80 year-old) with medical diagnosis of idiopathic Parkinson's disease in initial clinic stages were studied. The Unified Parkinson's Disease Rating Scale, Hoehn-Yahr Scale, and Schwab & England Scale were used to assess the clinic signs and symptoms. The depressive symptoms were identified by complete anamnesis, examination of mental condition, and the Hamilton Rating Scale for Depression and the Anxiety and Depression Scale. Statistical analysis was performed by Pearson's correlation and multiple regression analysis. Results. A significant correlation of severity of depression symptoms with disease stage (p < 0.02), with motor signs (p < 0.008), and with functional performance (p < 0.007) was found. Conclusion. There was significant association between motor impairment and severity of depressive symptoms, and between depression and early disease onset or prolonged duration of Parkinson's disease. © 2007, Revista de Neurología.

Digital versus conventional radiography for determination of primary incisor length

Aim: This in vitro study evaluated the accuracy of primary incisor lengths determined by digital and conventional radiography compared to the actual tooth length. Methods: Twenty extracted primary maxillary incisors were mounted in acrylic blocks. Tooth length was estimated by using a straight-line measurement provided by the distance measurement tool of a digital dental imaging system (Computed Dental Radiography, Schick Technologies Inc.) and conventional E-speed film radiographs by using a digital caliper. Two operators familiar with both radiographic methods performed the estimates. The estimated tooth lengths were compared to the actual tooth lengths measured with the digital caliper. Data were statistically analyzed by Dahlberg's equation, paired t test, Pearson's correlation coefficient and ANOVA at 5% significance level. Results: There were no statistically significant differences (p = 0.85) between tooth length estimated on digital and conventional radiographs. Admitting as clinically acceptable a 0.5-mm discrepancy between the actual tooth lengths and the radiographically estimated lengths, 60% of the radiographic measurements were considered as accurate. When the acceptable difference range was 1.0 mm, the accuracy of the radiographic measurements increased to 100%. Conclusions: Digital and conventional radiography provided similar tooth length measurements and were equivalent to the actual tooth lengths.

Economic growth with equity: challenges for Latin America

Includes bibliography

Bone mineral density on conventional and digitized images under different parameters of digitization and storage

Aim: To assess the bone mineral density on conventional and digitized images, comparing whether different parameters of digitization and storage change these values. Methods: Twenty radiographs were taken from five partially dentulous dry mandibles with an aluminum 7-mm stepwedge placed on the superior edge of the film. After processing, the films were digitized with a resolution of 600 and 2,400 d.p.i. and saved as TIFF and JPEG files. On every conventional and digitized image, circular regions of interest were selected for densitometry and radiographic contrast analysis. Results: Pearson's correlation coefficient showed a significant and strong mean gray values association between digitized and conventional images, differing from radiographic contrast that did not show a significant association. ANOVA did not reveal a statistically significant difference in bone density and radiographic contrast among the four digitized image groups, but the conventional image contrast was significantly lower. Conclusions: Bone mineral density did not differ in both conventional and digitized images. The parameters of image compression and resolution, tested in this study, did not change the results of densitometry and digitization process increased the radiographic contrast.

Modeling regional macroeconomic interactions: situation and perspectives for macroeconomic coordination in Latin America. Background paper prepared for the REDIMA workshop on Modeling Macroeconomic Coordination in the Andean Community, (Santiago, Chile 22 October 2003)""

Includes bibliography

AC biosusceptometry as a method for measuring gastric contraction

the aim of this study was to validate the Alternate Current Biosusceptometry (ACB) for monitoring gastric contractions in rats. In vitro data were obtained to establish the relationship between ACB and the strain-gauge (SG) signal amplitude. In vivo experiments were performed on rats with magnetic markers and SGs previously implanted under the gastric serosa. The effects of the prandial state in gastric motility profiles were obtained. The correlation between in vitro signal amplitudes was strong (R = 0.989). The temporal cross-correlation between the ACB and SG signal amplitude was higher in the postprandial than in the fasting state. Irregular signal profiles, low contraction amplitudes, and smaller signal-to-noise ratios explained the poor correlation for fasting-state recordings. The contraction frequencies using ACB were 0.068 ± 0.007 Hz (postprandial) and 0.058 ± 0.007 Hz (fasting) and those using SG were 0.066 ± 0.006 Hz (postprandial) and 0.059 ± 0.008 Hz (fasting) (P < 0.003). When a magnetic tracer was ingested, there was a strong correlation and a small phasedifference between techniques. We conclude that ACB provides an accurate and sensitive technique for studies of GI motility in the rat. © 2010 IEEE.

Influence of high insertion torque on implant placement - an anisotropic bone stress analysis

The aim of this study was to evaluate the influence of the high values of insertion torques on the stress and strain distribution in cortical and cancellous bones. Based on tomography imaging, a representative mathematical model of a partial maxilla was built using Mimics 11.11 and Solid Works 2010 softwares. Six models were built and each of them received an implant with one of the following insertion torques: 30, 40, 50, 60, 70 or 80 Ncm on the external hexagon. The cortical and cancellous bones were considered anisotropic. The bone/implant interface was considered perfectly bonded. The numerical analysis was carried out using Ansys Workbench 10.0. The convergence of analysis (6%) drove the mesh refinement. Maximum principal stress (σ max) and maximum principal strain (ε max) were obtained for cortical and cancellous bones around to implant. Pearson's correlation test was used to determine the correlation between insertion torque and stress concentration in the periimplant bone tissue, considering the significance level at 5%. The increase in the insertion torque generated an increase in the σ max and ε max values for cortical and cancellous bone. The σmax was smaller for the cancellous bone, with greater stress variation among the insertion torques. The ε max was higher in the cancellous bone in comparison to the cortical bone. According to the methodology used and the limits of this study, it can be concluded that higher insertion torques increased tensile and compressive stress concentrations in the periimplant bone tissue.

Influence of the construction bite vertical and horizontal dimensions on dentoskeletal structures induced by the Klammt appliance in Class II treatment

Aim: To evaluate the influence of construction bite in the dentoskeletal changes induced by Klammt Appliance. Methods: The sample consisted of 17 children, with Class II malocclusion and initial mean age of 8.5 years. The construction bite was obtained using an Exactobite on edge-toedge anteroposterior relationship with 3 mm interincisal clearance. The height of the acrylic was determined by initial overbite associated to interincisal clearance and measured with digital caliper. The amount of advancement was obtained and measured by initial overjet in the lateral radiography. Pearson's correlation, linear regression and ANOVA were used to determine the relationship between dentoskeletal and construction bite variables. Results: The increase in the height of the acrylic promotes a greater inhibition of the forward displacement of the nasal spine and reduction in the facial growth index. The increase in the mandibular advancement induces more downward displacement of nasal spine and pogonion; a counter-clockwise rotation of palatine plane; an increase in mandibular length, maxillary alveolar height and interincisal angle; a decrease in mandibular alveolar height, the intermaxillary discrepancy and overjet; and palatal tipping of upper incisors. Conclusions: The different dimensions of the construction bite influence the dentoskeletal changes induced by the appliance in Class II treatment.

Expenditures, investment and financing for sustainable development in Brazil

Includes bibliography

Educação estatística no contexto da educação crítica

This article deals with the development of three competencies defined and studied in the context of Statistics Education (literacy, thinking and statistical reasoning). These competencies based on interpretation and understanding of critical information from real data are associated with an education geared toward the formation of critical citizenship and are in agreement with the principles that guide Critical Education. In this context, we consider Mathematical Modeling as a concrete possibility for integration between Critical Education and Education Statistics. We show that work with modeling projects in the classroom takes place in a context in which teaching is guided by the fundamentals of Critical Education. We present a project entitled Teaching Statistics and the financial market which illustrates the congruence between the objectives of Education Statistics and Critical Education.