Nonlinear Analysis of Thin Fracture Specimens Using Solid, Isoparametric Finite Elements

This report examines the performance of various "solid" finite elements for the analysis of thin shell structures often encountered in nonlinear fracture mechanics studies. Such models require solid elements in the crack front region to capture strong through-thickness effects; modeling of the entire test specimen-structural element with solid elements then proves convenient. Unfortunately, the standard 8-node "brick" element with full integration exhibits strong shear-locking under bending deformations and thus overly stiff behavior. Three alternative elements are examined here: the 8-node element with single-point integration, the 8-node element with enhanced (incompatible) modes and the 20-node (quadratic) element. Element performance is assessed through analyses of a thin M(T) fracture specimen loaded in remote tension. This specimen generates strong compressive (T- )stresses parallel to the crack growth direction which leads to out-of-plane bending in the crack front region (triggered by a small normal force). The displacements obtained with a refined mesh of thin shell elements provide the reference solution for evaluation of the solid element performance. The analyses include large-displacement effects, but linear material response for simplicity, and are performed with Abaqus 5.6 and Warp3D. The results show clearly that both the 8-node element with enhanced modes and the 20-node element with conventional reduced integration provide solutions of accuracy comparable to the thin shell element. Mixed 8 and 20-node element meshes for ductile fracture analyses with transition elements to maintain displacement compatibility are demonstrated to provide an accurate and efficient modeling strategy.NASA-AMES Research CenterNASA-Langley Research CenterContract Nos. NCC 2-5126 and NAG 2-112

Chronic Obstructive Pulmonary Disease in Portugal: Pneumobil (1995) and 2002 prevalence studies revisited

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) has been a leading cause of morbidity and mortality worldwide, over the years. In 1995, the implementation of a respiratory function survey seemed to be an adequate way to draw attention to neglected respiratory symptoms and increase the awareness of spirometry surveys. By 2002 there were new consensual guidelines in place and the awareness that prevalence of COPD depended on the criteria used for airway obstruction definition. The purpose of this study is to revisit the two studies and to turn public some of the data and respective methodologies. METHODS: From Pneumobil study database of 12,684 subjects, only the individuals with 40+ years old (n = 9.061) were selected. The 2002 study included a randomized representative sample of 1,384 individuals with 35-69 years old. RESULTS: The prevalence of COPD was 8.96% in Pneumobil and 5.34% in the 2002 study. In both studies, presence of COPD was greater in males and there was a positive association between presence of COPD and older age groups. Smokers and ex-smokers showed a higher proportion of cases of COPD. CONCLUSIONS: Prevalence in Portugal is lower than in other European countries. This may be related to lower smokers' prevalence. Globally, the most important risk factors associated with COPD were age over 60 years, male gender and smoking exposure. All aspects and limitations regarding different recruitment methodologies and different criteria for defining COPD cases highlight the need of a standardized method to evaluate COPD prevalence and associated risks factors, whose results can be compared across countries, as it is the case of BOLD project

Elective appendicovesicostomy in association with monfort abdominoplasty in the treatment of prune belly syndrome

OBJECTIVE: To evaluate the role of elective appendicovesicostomy in association with Monfort abdominoplasty to avoid urinary tract infection (UTI) and renal damage in the post-operative follow-up of patients with prune belly syndrome. MATERIALS AND METHODS: We followed 4 patients operated in our institution (UNIFESP) (Monfort, orchidopexy and Mitrofanoff) and compared them to 2 patients treated similarly, but without an appendicovesicostomy, in a second institution (UFBA). We evaluated postoperative clinical complications, UTI and preservation of renal parenchyma. Patients were followed as outpatients with urinalysis, ultrasonography (US) and occasionally with renal scintigraphy. RESULTS: Mean follow-up was 23.5 months. Immediate post-operative course was uneventful. We observed that only one patient with the Mitrofanoff channel persisted with UTI, while the 2 patients used as controls persisted with recurrent pyelonephritis (> 2 UTI year). CONCLUSION: Our data suggest that no morbidity was added by the appendicovesicostomy to immediate postoperative surgical recovery and that this procedure may have a beneficial effect in reducing postoperative UTI events and their consequences by reducing the postvoid residuals in the early abdominoplasty follow-up. However, we recognize that the series is small and only a longer follow-up with a larger number of patients will allow us to confirm our suppositions. We could not make any statistically significant assumptions regarding differences in renal preservation due to the same limitations.Federal University of São Paulo Division of UrologyFederal University of Bahia Division of UrologyUNIFESP, Division of UrologySciEL

Triangular flap technique for medial thighplasty after massive weight loss in women

INTRODUÇÃO: Com o aumento do número de pacientes submetidos à cirurgia bariátrica, cresce também a realização de procedimentos reparadores visando à melhoria do contorno corporal. MÉTODO: Descrevemos uma variação técnica de cruroplastia medial em "T" com adição de um retalho cutâneo triangular, de base superior, interrompendo a incisão horizontal que corre na prega inguinal. Esse retalho fica posicionado no ponto de maior tração crânio-caudal correspondente ao intróito vaginal e ao tendão do músculo adutor. A técnica foi empregada em 18 pacientes. RESULTADOS: A média de idade das pacientes foi de 47 anos; 22% apresentavam comorbidades (hipertensão, diabete mellitus, varizes). Todas haviam sido submetidas à cirurgia bariátrica num período médio de pós-operatório de 63 meses, sendo o IMC médio antes da cirurgia bariátrica de 48 e antes da cruroplastia de 29 kg/m². Sete (39%) pacientes foram submetidas a outro procedimento simultaneamente à cruroplastia. A incidência de cicatrização retardada foi de 25%, deiscências de 8% e de cicatrizes hipertróficas de 11%. Nenhuma delas apresentou tração lateral da vulva ou migração caudal de cicatrizes ao longo do seguimento médio de 10 meses. CONCLUSÕES: A utilização do retalho triangular mostrou ser uma variação técnica viável que evitou tração lateral da vulva e minimizou a migração inferior de cicatrizes.BACKGROUND: The increasing number of patients who undergo bariatric surgery implies on a greater demand of reparative procedures for improvement of body contour. METHODS: We describe a variation technique medial "T" thighplasty with addition of a triangular skin flap from the upper base, breaking the horizontal incision that runs the inguinal crease. This flap is positioned at the point of greatest traction craniocaudal corresponding to the vaginal opening and the tendon of the adductor muscle. The technique was employed in 18 patients. RESULTS: The mean age of patients was 47 years, 22% had comorbidities (hypertension, diabetes mellitus and varicose disease). All had undergone bariatric surgery at a mean period of postoperative 63 months, mean BMI before bariatric surgery 48 and before thighplasty of 29 kg/m². Seven (39%) patients underwent another procedure at the same intervention. The incidence of delayed healing was 25%, dehiscence of 8% and 11% of hypertrophic scars. None of them has traction side of the vulva or migration flow scars along the mean follow up of 10 months. CONCLUSIONS: The use of the triangular flap for medial thighplasty after major weight loss was shown to be a viable technical change that minimized the pull side of the vulva and the inferior migration of scars

Towards a runtime verification framework for the Ada Programming Language

Runtime verification is an emerging discipline that investigates methods and tools to enable the verification of program properties during the execution of the application. The goal is to complement static analysis approaches, in particular when static verification leads to the explosion of states. Non-functional properties, such as the ones present in real-time systems are an ideal target for this kind of verification methodology, as are usually out of the range of the power and expressiveness of classic static analyses. In this paper, we present a framework that allows real-time programs written in Ada to be augmented with runtime verification capabilities. Our framework provides the infrastructures which is needed to instrument the code with runtime monitors. These monitors are responsible for observing the system and reaching verdicts about whether its behavior is compliant with its non-functional properties. We also sketch a contract language to extend the one currently provided by Ada, with the long term goal of having an elegant way in which runtime monitors can be automatically synthesized and instrumented into the target systems. The usefulness of the proposed approach is demonstrated by showing its use for an application scenario.This work was partially supported by Portuguese National Funds through FCT (Portuguese Founda- tion for Science and Technology) and by ERDF (European Regional Develop- ment Fund) through COMPETE (Operational Programme ’Thematic Factors of Competitiveness’), within projects FCOMP-01-0124-FEDER-037281 (CISTER), FCOMP-01-0124-FEDER-015006 (VIPCORE) and FCOMP-01-0124-FEDER- 020486 (AVIACC); and by FCT and EU ARTEMIS JU, within project ARTEMIS/0003/2012, JU grant nr. 333053 (CONCERTO)

Phage inducible islands in the gram-positive cocci

The SaPIs are a cohesive subfamily of extremely common phage-inducible chromosomal islands (PICIs) that reside quiescently at specific att sites in the staphylococcal chromosome and are induced by helper phages to excise and replicate. They are usually packaged in small capsids composed of phage virion proteins, giving rise to very high transfer frequencies, which they enhance by interfering with helper phage reproduction. As the SaPIs represent a highly successful biological strategy, with many natural Staphylococcus aureus strains containing two or more, we assumed that similar elements would be widespread in the Gram-positive cocci. On the basis of resemblance to the paradigmatic SaPI genome, we have readily identified large cohesive families of similar elements in the lactococci and pneumococci/streptococci plus a few such elements in Enterococcus faecalis. Based on extensive ortholog analyses, we found that the PICI elements in the four different genera all represent distinct but parallel lineages, suggesting that they represent convergent evolution towards a highly successful lifestyle. We have characterized in depth the enterococcal element, EfCIV583, and have shown that it very closely resembles the SaPIs in functionality as well as in genome organization, setting the stage for expansion of the study of elements of this type. In summary, our findings greatly broaden the PICI family to include elements from at least three genera of cocci