Functional Capacity of Patients with Pacemaker Due to Isolated Congenital Atrioventricular Block

Background:Isolated congenital atrioventricular block (CAVB) is a rare condition with multiple clinical outcomes. Ventricular remodeling can occur in approximately 10% of the patients after pacemaker (PM) implantation.Objectives:To assess the functional capacity of children and young adults with isolated CAVB and chronic pacing of the right ventricle (RV) and evaluate its correlation with predictors of ventricular remodeling.Methods:This cross-sectional study used a cohort of patients with isolated CAVB and RV pacing for over a year. The subjects underwent clinical and echocardiographic evaluation. Functional capacity was assessed using the six-minute walk test. Chi-square test, Fisher's exact test, and Pearson correlation coefficient were used, considering a significance level of 5%.Results:A total of 61 individuals were evaluated between March 2010 and December 2013, of which 67.2% were women, aged between 7 and 41 years, who were using PMs for 13.5 ± 6.3 years. The percentage of ventricular pacing was 97.9 ± 4.1%, and the duration of the paced QRS complex was 153.7 ± 19.1 ms. Majority of the subjects (95.1%) were asymptomatic and did not use any medication. The mean distance walked was 546.9 ± 76.2 meters and was strongly correlated with the predicted distance (r = 0.907, p = 0.001) but not with risk factors for ventricular remodeling. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0)Conclusions:The functional capacity of isolated CAVB patients with chronic RV pacing was satisfactory but did not correlate with risk factors for ventricular remodeling.

Association Between Hemodynamic Profile, Physical Capacity and Quality of Life in Pulmonary Hypertension

Background: No studies have described and evaluated the association between hemodynamics, physical limitations and quality of life in patients with pulmonary hypertension (PH) without concomitant cardiovascular or respiratory disease. Objective: To describe the hemodynamic profile, quality of life and physical capacity of patients with PH from groups I and IV and to study the association between these outcomes. Methods: Cross-sectional study of patients with PH from clinical groups I and IV and functional classes II and III undergoing the following assessments: hemodynamics, exercise tolerance and quality of life. Results: This study assessed 20 patients with a mean age of 46.8 ± 14.3 years. They had pulmonary capillary wedge pressure of 10.5 ± 3.7 mm Hg, 6-minute walk distance test (6MWDT) of 463 ± 78 m, oxygen consumption at peak exercise of 12.9 ± 4.3 mLO2.kg-1.min-1 and scores of quality of life domains < 60%. There were associations between cardiac index (CI) and ventilatory equivalent for CO2 (r=-0.59, p <0.01), IC and ventilatory equivalent for oxygen (r=-0.49, p<0.05), right atrial pressure (RAP) and 'general health perception' domain (r=-0.61, p<0.01), RAP and 6MWTD (r=-0.49, p<0.05), pulmonary vascular resistance (PVR) and 'physical functioning' domain (r=-0.56, p<0.01), PVR and 6MWTD (r=-0.49, p<0.05) and PVR index and physical capacity (r=-0.51, p<0.01). Conclusion: Patients with PH from groups I and IV and functional classes II and III exhibit a reduction in physical capacity and in the physical and mental components of quality of life. The hemodynamic variables CI, diastolic pulmonary arterial pressure, RAP, PVR and PVR index are associated with exercise tolerance and quality of life domains.

Vinhaça e adubos minerais(I)

In this paper it is studied the action of vinasse as compared to mineral fertilizers. Beans, corn, cotton and sesame were cultivated in randomized blocks receiving the following treatments: A = mineral fertilizers (N, P, K); V = vinasse at the rate of 1,000,000 liters per Ha; AV = mineral fertilizers + vinasse; T = control. Statistical analysis of the experiments has consistently revealed the superiority of vinasse either combined or not with the mineral fertilizers over the remaining treatments. There was no significant difference between V and AV which shows the surprizing role of vinasse when applied to light soils such as those employed in the present experiments. By employing 1,000,000 liters of vinasse to the hectare the following amounts of nutrientes were applied to the crops in this experiment: 470 Kg of nitrogen 50 Kg of P2O5 and 3,100 Kg of K2O corresponds to 3,133 Kg of Chilean nitrate/ha 250 Kg of superphosphate and 5,160 Kg of muriate of potash Hence one cannot say that the action of vinasse is of a purely physical nature. In our opinion its outstanding action is due to: 1st raise in the pH value of the soil; 2nd addition of a tremendous amount of plant nutrients; 3rd supplying organic matter in a very finely divided state with all its benefical effects in soil structure, water holding capacity, adsorption of nutrients to prevent leaching, etc. A rotation experiment is now being carried out to study the residual effect of vinasse.

Avaliação da capacidade de fixação de fósforo pelo solo

Phosphate "fixation" is the convertion of soluble into insoluble phosphate in the soil. There are many factors conditioning phosphate fixation by soil such as reactions originating less soluble compounds (phosphates of iron, aluminum, calcium, magnesium, etc.), PO4-3 adsorption by the colloidal fraction of soils, PO4-3 absorption by the soil microflora, etc. Certain soils of the state of São Paulo (Brazil) are relatively rich in both iron and aluminum oxides. PO4-3 fixation, using P31 and P32 has been verified by researchers, specially with "Terra Roxa". The known methods for fixation evaluation are conventional as this depends on phosphate solution concentration, pH, time of contact between soil and solution, relation of sample weight to solution volume, shaking time, etc. In this experiment, the following conventional method was used: 4 g of soil were shaken for 15 minutes at 30-40 rpm, in 300 ml Erlenmeyer flask in a Wagner shaking machine, together with 100 ml of 0,03 normal phosphate solution (being 0,01 normal as PO4-3 contributed by H8PO4 and 0,02 normal as PO4-3 from KH2PO4). After shaking it was set aside for 24 hours and then filtered. Phosphate was determined in a suitable aliquot of both the original solution (blank) and the soil extract, by the vanadomolibidic-phosphoric acid method. From phosphate concentration in the blank minus phosphate concentration in the soil stract the rate of fixation by 100 g of soil was calculated. The data obtained show that "Terra Roxa" and "Terra Roxa Misturada" have a fairly high PO4-3 fixation capacity, varying from 10 to 24 milliequivalents of PO4-3 per 100 g of soil.

A soro-aglutinação das Leishmanias

The first agglutination experiments (Tables 1 and 2) showed that the serum obtained with any one strain of Leishmania, agglutinates all the others even of another species. This finding reveals the existence of a common antigen. However as the titre of agglutination did not permit a sharp differentiation of species we tried the adsorption method. The first adsorption tests made demonstrated differences in antigenic constitution between a strain of. L. donovani on one hand and strains of L. tropica or L. brasiliensis on the other. Further experiments in which L. chagasi was tested against the other species revealed that the former was antigenically different from the others. These tests were performed by adsorbing an anti-chagasi serum with organisms belonging to the other species or, conversely, adsorbing with L. chagasi sera prepared against the other species (See Tables 9 to 24). On the other hand, the adsorption of a serum prepared against one strain of l. chagasi by another of the same species showed that they had identifical antigenie constitution. These findings suggested the possibility of separating different species of Leishmania by this method. However, tests to separate the other species from one to another gave inconclusive results. (See Tables 27 to 35). It was soon observed that all the strains of L. chagasi were of recent isolation while all the others had been maintained in artificial culture media for a long time. We were led to believe that this condition was responsible for the differences in behaviour encountered. Accordingly, recently isolated strains of L. brasiliensis and L. donovani were tested and shown to be antigenically similar to strains of L. chagasi also recently isolated. The conclusion may be drawn that all strains have the same antigenic constitution when freshly isolated. It has been noted that when a serum which has been prepared against a freshly isolated is adsorbed with an old strain, the amount of agglutinins left free, is much smaller than when a serum prepared against an old strain is adsorbed with a newly isolated strain. At first, we thought to explain this by the low titre of the serum. However, the amount of agglutinins left free was not larger when higher titre serum was tested. The results do not corroborate the view of a special antigen being present in recently isolated strains (vi antige) but rather that the phenomenon is dependent on differences of the amount of the common antigen, more abundant in recent strains. In order to make this clear, experiments were made in which equal amounts of a serum prepared against a newly isolated strain were adsorbed by equal amounts, by weight, of, on one hand, a new strain, and the other an old strain. The resulting adsorbed sera were then titrated. (Table 44). Results showed that newly isolated strains adsorb a larger amount of agglutinins (Tables 44, 45). Two hypothesis have bem advanced to explain the stronger adsorbing qualities of the newly isolated strains. 1° - these strains possess larger amounts of the common antigen and 2° - they contain a vi antigen which adsorbed by the new strain together with the common antigen is the cause of their larger adsorbing capacity. To find out which of the two hypothesis corresponds to the reality a new experiment was made, similar to the one summarized in table 44. The adsorbed sera were made to act on a recently isolated strain as well as on an old one. The latter, not containing the vi antigen, the difference seen when sera act on new strains should not be observed here in the case of this antigen being responsible for the differences in adsorbing properties. The difference persisting, the indication would be that the greater adsorbing capacity of recently isolated strains was really related to larger amounts of the common antigen present (Tables 46 and 47). The results of the experiment excluded the possibility of the vi antigen being responsible. Other experiments, (Tables 48 to 53) using a 3 year old strain, demonstrated the modification in its antigenic constitution during the period it was maintained in cultures.

Tacit collusion and capacity withholding in repeated uniform price auctions

This paper contributes to the study of tacit collusion by analyzing infinitely repeated multiunit uniform price auctions in a symmetric oligopoly with capacity constrained firms. Under both the Market Clearing and Maximum Accepted Price rules of determining the uniform price, we show that when each firm sets a price-quantity pair specifying the firm's minimum acceptable price and the maximum quantity the firm is willing to sell at this price, there exists a range of discount factors for which the monopoly outcome with equal sharing is sustainable in the uniform price auction, but not in the corresponding discriminatory auction. Moreover, capacity withholding may be necessary to sustain this out-come. We extend these results to the case where firms may set bids that are arbitrary step functions of price-quantity pairs with any finite number of price steps. Surprisingly, under the Maximum Accepted Price rule, firms need employ no more than two price steps to minimize the value of the discount factor

Forward induction and the excess capacity puzzle: An experimental investigation.

While the theoretical industrial organization literature has long argued that excess capacity can be used to deter entry into markets, there is little empirical evidence that incumbent firms effectively behave in this way. Bagwell and Ramey (1996) propose a game with a specific sequence of moves and partially-recoverable capacity costs in which forward induction provides a theoretical rationalization for firm behavior in the field. We conduct an experiment with a game inspired by their work. In our data the incumbent tends to keep the market, in contrast to what the forward induction argument of Bagwell and Ramey would suggest. The results indicate that players perceive that the first mover has an advantage without having to pre-commit capacity. In our game, evolution and learning do not drive out this perception. We back these claims with data analysis, a theoretical framework for dynamics, and simulation results.

Asymmetries in the capacity-inflation trade-off

This paper analyzes the joint dynamics of two key macroeconomic variables for the conduct of monetary policy: inflation and the aggregate capacity utilization rate. An econometric procedure useful for estimating dynamic rational expectation models with unobserved components is developed and applied in this context. The method combines the flexibility of the unobserved components approach, based on the Kalman recursion, with the power of the general method of moments estimation procedure. A 'hyb id' Phillips curve relating inflation to the capacity utilization gap and incorporating forward and backward looking components is estimated. The results show that such a relationship in non-linear: the slope of the Phillips curve depends significantly on the magnitude of the capacity gap. These findings provide support for studying the implications of asymmetricmonetary policy rules.

Endogenous capacity utilization and the asymmetric effects of monetary policy

This paper investigates the role of variable capacity utilization as a source of asymmetries in the relationship between monetary policy and economic activity within a dynamic stochastic general equilibrium framework. The source of the asymmetry is directly linked to the bottlenecks and stock-outs that emerge from the existence of capacity constraints in the real side of the economy. Money has real effects due to the presence of rigidities in households' portfolio decisions in the form of a Luces-Fuerst 'limited participation' constraint. The model features variable capacity utilization rates across firms due to demand uncertainty. A monopolistic competitive structure provides additional effects through optimal mark-up changes. The overall message of this paper for monetary policy is that the same actions may have different effects depending on the capacity utilization rate of the economy.

Lipschitz harmonic capacity and Bilipschitz images of cantor sets

For bilipschitz images of Cantor sets in Rd we estimate the Lipschitz harmonic capacity and show this capacity is invariant under bilipschitz homeomorphisms.

The retained capacity of Lutzomya longipalpis (Lutz & Neiva) to transmit Leishmania chagasi (Cunha & Chagas) after eight years (64 generations in a closed laboratory colony

A closed Lutzomyia longipalpis colony, from Ceará has been used to transmit Leishmania chagasi isolated from a fox in Pará state. The last time this colony was successfully used in similar transmission experiments was eight years (64 generations) ago indicating that this colony of Lu. longipalpis has fully maintained its vectorial capacity in spite of such a long period of maintainance in the laboratory.