O Papel das Prostaglandinas na Dinâmica do Tracto Urinário Inferior de Doentes Prostatectomizados: um Ensaio com Indometacina e Aspirina

Using 49 prostatectomized patients as experimental subjects, we studied the effects of Inclometnacin and acetylsalicylic acid — accredited prostaglandin synthetase inhibitors — from a urodynamic and clinical standpoint. Relevant urodynamic data was gathered 1 hr 30 mi after the patients had taken the drugs and placebo. Clinical results were further scrutinized after 8 days of treatment, at which time a new urodynamic workup was again performed on some patients. Results were again studied shortly after the end of treatment. The effect of the drugs on bladder and urethral structures was borne out by clear-ct!t clinical and urodynamic changes. After statistically analyzing such changes, we concluded that prostaglandin synthesis inhibition resulting in the inhibition of prostaglandin action had, at least in part, led to the changes noted. In the present report we shall discuss the role played by the highly complex mechanisms at work

Artificial Neural Network Symbol Estimator With Enhanced Robustness to Nonlinear Phase Noise

This letter reports a novel approach for nonlinear phase noise mitigation, based on artificial neural networks (ANNs) tailored to classification applications and a pre-processing stage of feature engineering. Starting with a set of proof-of-concept simulations, we verify that the proposed system can achieve optimal performance for the additive white Gaussian noise (AWGN) channel. Then, considering a dispersion-less channel with strong nonlinear phase noise (NLPN) distortion, we demonstrate a Q-factor increase of 0.4dB, comparing with standard carrier-phase estimation (CPE) followed by minimum distance detection. Finally, simulating the propagation of 64Gbaud PM-16QAM over standard single mode fiber (SSMF), we verify that the ANN-based solution is effective on wavelength-division multiplexing (WDM) transmission conditions, enabling to increase the maximum signal reach by approximately 1 fiber span over the legacy CPE-enabled NLPN compensation

Life-cycle costing of metallic structures

Structural material selection has traditionally been based on Initial material cost. However, growing pressure on the construction industry to consider the longer-term financial and environmental implications of projects is encouraging a more holistic view. Thus, materials with higher initial costs, but which offer cost savings over the life cycle of a structure, are gaining increasing recognition. The life-cycle costs of structures of two such metallic materials, namely aluminium alloy and stainless steel, are compared with those of ordinary structural carbon steel in the present study. Two structural applications - a typical office building and a bridge - are analysed, while offshore applications are briefly discussed. The ratio of initial material cost per tonne was assumed to be 1.0:2.5:4.0 (carbon steel:aluminium alloy:stainless steel). Following a preliminary structural design to current European design standards taking due account of the material densities and structural properties (principally strength and stiffness), it was found that on an initial cost basis, carbon steel offers the most competitive solution for both the building and the bridge. However, considering the additional life-cycle costs including maintenance costs, end-of-life costs and the residual value of the structure (appropriately discounted to present values), the results indicate that carbon steel offers the most competitive life-cycle solution for the office building but delivers the most expensive life-cycle solution for the bridge. Overall, it is concluded that on a whole-life basis aluminium alloy and stainless steel may offer more competitive solutions than carbon steel for bridges and exposed areas of building structures

Counterfactual thinking in cooperation dynamics

Counterfactual Thinking is a human cognitive ability studied in a wide variety of domains. It captures the process of reasoning about a past event that did not occur, namely what would have happened had this event occurred, or, otherwise, to reason about an event that did occur but what would ensue had it not. Given the wide cognitive empowerment of counterfactual reasoning in the human individual, the question arises of how the presence of individuals with this capability may improve cooperation in populations of self-regarding individuals. Here we propose a mathematical model, grounded on Evolutionary Game Theory, to examine the population dynamics emerging from the interplay between counterfactual thinking and social learning (i.e., individuals that learn from the actions and success of others) whenever the individuals in the population face a collective dilemma. Our results suggest that counterfactual reasoning fosters coordination in collective action problems occurring in large populations, and has a limited impact on cooperation dilemmas in which coordination is not required. Moreover, we show that a small prevalence of individuals resorting to counterfactual thinking is enough to nudge an entire population towards highly cooperative standards.Comment: 18 page

Low bone turnover is associated with plain X-ray vascular calcification in predialysis patients

Background Vascular calcification (VC) is a common finding in chronic kidney disease (CKD) patients and predicts subsequent cardiovascular morbidity and mortality in this population. Vascular calcification is linked to disordered mineral metabolism and has been associated with bone histomorphometry changes in CKD. However, data on predialysis patients is scarce. Methods A cross-sectional study was conducted on a cohort of 56 CKD patients not yet on dialysis, who underwent a transiliac bone biopsy for histomorphometric evaluation after double tetracycline labeling. Patients had no previous exposure to calcium salts, vitamin D agents, steroids or bisphosphonates. Vascular calcification was assessed at the time of biopsy, using Kauppila (plain X-ray of the lateral lumbar spine) and Adragão (plain X-ray of the pelvis and hands) scores. Results Vascular calcification was seen in two-thirds of the cohort. Subjects with VC were more likely to be male and have diabetes, and had significantly higher sclerostin and osteoprotegerin circulating levels than those without VC. The histomorphometric analysis showed that bone formation rate was significantly lower in VC compared to non-VC patients. In the multivariable logistic regression analysis, bone formation rate was independently associated with the presence of VC. Conclusions Vascular calcification is highly prevalent in predialysis patients, especially in those with diabetes. The independent association between bone formation rate and VC provides evidence of an important interaction between bone and vessel in CKD. Our results suggest that low bone turnover is a non-traditional risk factor for cardiovascular disease in predialysis patients

Renal Artery Angioplasty

Efectuámos angioplastia transiuminal percutânea (ATP) da artéria renal em 59 doentes hipertensos e houve benefício inicial na tensão arterial em 91,5% e tardio em 79,6%. Obtivemos melhores resultados nas lesões unilaterais (81,4%) do que nas bilaterais (72,7%); nas lesões fora do ostium (82,5%) do que nas do ostium (7 1,4%); nas lesões de origem fibromuscular (88,9%) do que nas de origem aterosclerótica(75%); e nos doentes com idade igual ou inferior a 55 anos (84,8%) do que em doentes com idade superior (71,4%). Estas diferenças não foram contudo significativas. Os bons resultados da ATP da artéria renal na hipertensão renovascular levam-nos a considerar esta forma de intervenção como uma alternativa do seu tratamento

Mesoscopic structure conditions the emergence of cooperation on social networks

We study the evolutionary Prisoner's Dilemma on two social networks obtained from actual relational data. We find very different cooperation levels on each of them that can not be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal structure of the communities and their interconnections. We then test our results on community-structured, specifically designed artificial networks, finding perfect agreement with the observations in the real networks. Our results support the conclusion that studies of evolutionary games on model networks and their interpretation in terms of global properties may not be sufficient to study specific, real social systems. In addition, the community perspective may be helpful to interpret the origin and behavior of existing networks as well as to design structures that show resilient cooperative behavior.Comment: Largely improved version, includes an artificial network model that fully confirms the explanation of the results in terms of inter- and intra-community structur

The role of the FtsA protein in Bacillus subtilis cell division

University of Technology, Sydney. Faculty of Science.Bacterial cell division involves the invagination of the membrane and the cell wall to form a septum at midcell, between two replicated chromosomes. From a molecular perspective, the main event in cell division is the formation of a circumferential structure, the Z ring, formed by polymerisation of the tubulin-like FtsZ protein. The Z ring recruits a multi-protein complex to the division site, forming a division apparatus that eventually constricts as the septum forms. FtsA, a eukaryotic actin homologue, is another division protein, known to interact directly with FtsZ. It has been proposed that FtsA promotes Z ring formation; however its exact role has remained unknown. This thesis investigateshow FtsA affects the Z ring and cytokinesis in the Gram-positive model organism, Bacillus subtilis. Interestingly, FtsA is essential in Escherichia coli, the Gram-negative model organism, but not in Bacillus subtilis. Rather, deletion of the ftsA gene in vegetatively-growing B. subtilis cells causes a significant reduction in Z ring formation and cell division is severely diminished while cell growth is maintained, resulting in cell filamentation (long cells without septa). To confirm that this phenotype is due to the inability of FtsZ to efficiently form rings, Z ring formationwas examined in the absence of FtsA, during the first round of cell division following B. subtilis spore germination. Surprisingly the Z rings formed with wild-type efficiency. However, unlike wild-type cells that showed subsequent constriction of these Z rings leading to septum formation, Z rings did not constrict immediately in the ftsA mutant and persisted into the second cycle of division. These results reveal for the first time that, unlike E. coli, FtsA is not required for Z ring formation in B. subtilis. To understand the delay in Z ring constriction, further experiments were conducted to determine if the recruitment of downstream division proteins to the Z ring is affectedin the absence of FtsA. The live-cell microscopy data confirmed that the recruitment of DivIB, and presumably other downstream division proteins that are co-recruited with DivIB, is delayed in ftsA-mutant cells, but occurs with wild-type efficiency. However, after recruitment of DivIB, Z ring constriction and septation are still inefficient in the absence of FtsA. These observations indicate a primary role for FtsA in B. subtilis in the later stages of division, that is, after the division apparatus has assembled. This work reveals a novel perspective on the function of this protein. In an attempt to further explore how Z ring constriction is affected by FtsA, microscopy studies were designed to analyse this cell process. Different Z ring constriction defects were observed in ftsA-mutant cells. Importantly, it was shown that, in the absence of FtsA, constriction is either significantly delayed or never occurs, resulting in destabilisation of the Z ring, indicating that FtsA is required for efficient Z ring constriction in B. subtilis. This finding raised the possibility that FtsA may be affecting the dynamics of the Z ring during cytokinesis. To verify this, the rate of FtsZ turnover in Z rings of ftsA-mutant cells was investigated. The results demonstrated a decrease in the rate of the FtsZ turnover in the Z ring in the absence of FtsA, possibly enough to cause an effect on Z ring constriction