A Method to Tackle First Order Differential Equations with Liouvillian Functions in the Solution - II

We present a semi-decision procedure to tackle first order differential equations, with Liouvillian functions in the solution (LFOODEs). As in the case of the Prelle-Singer procedure, this method is based on the knowledge of the integrating factor structure.Comment: 11 pages, late

Solving 1ODEs with functions

Here we present a new approach to deal with first order ordinary differential equations (1ODEs), presenting functions. This method is an alternative to the one we have presented in [1]. In [2], we have establish the theoretical background to deal, in the extended Prelle-Singer approach context, with systems of 1ODEs. In this present paper, we will apply these results in order to produce a method that is more efficient in a great number of cases. Directly, the solving of 1ODEs is applicable to any problem presenting parameters to which the rate of change is related to the parameter itself. Apart from that, the solving of 1ODEs can be a part of larger mathematical processes vital to dealing with many problems.Comment: 31 page

Measurement Bounds for Sparse Signal Ensembles via Graphical Models

In compressive sensing, a small collection of linear projections of a sparse signal contains enough information to permit signal recovery. Distributed compressive sensing (DCS) extends this framework by defining ensemble sparsity models, allowing a correlated ensemble of sparse signals to be jointly recovered from a collection of separately acquired compressive measurements. In this paper, we introduce a framework for modeling sparse signal ensembles that quantifies the intra- and inter-signal dependencies within and among the signals. This framework is based on a novel bipartite graph representation that links the sparse signal coefficients with the measurements obtained for each signal. Using our framework, we provide fundamental bounds on the number of noiseless measurements that each sensor must collect to ensure that the signals are jointly recoverable.Comment: 11 pages, 2 figure

One Money, Many Markets - A Factor Model Approach to Monetary Policy in the Euro Area with High-Frequency Identification

We reconsider the effects of common monetary policy shocks across countries in the euro area, using a data-rich factor model and identifying shocks with high-frequency surprises around policy announcements. We show that the degree of heterogeneity in the response to shocks, while being low in financial variables and output, is significant in consumption, consumer prices and macro variables related to the labour and housing markets. Mirroring country-specific institutional and market differences, we find that home ownership rates are significantly correlated with the strength of the housing channel in monetary policy transmission. We document a high dispersion in the response to shocks of house prices and rents and show that, similar to responses in the US, these variables tend to move in different directions

FLAME PROFILE IN A POROUS RADIANT BURNER USING 1/2” AND 1/4” ALUMINA’S SPHERES

Porous burners are known by their high efficiency and low polluting gases emissions. Their high efficiency is given by the great thermal radiation potential, whereas differently a normal burner, the process of combustion happens in the inner of the porous medium, which is compound by spheres of alumina, and the mix air-fuel goes through the preheating zone, potentializing the combustion. The burners are usually used in the industry, in the process of drying of paper and wood, plastic coating, food cooking and ambient heating. In this article, it was studied the behaviour of the flame in a porous radiant burner with alumina’s sphere of 1/2” and 1/4”, using LPG as fuel, compressed air as oxidizing agent and ceramic wool as thermal insulation. The burner was divided in three essential sections with a type K thermocouple in each one, which are: base, middle and top. The flame profile encountered was a floating one, however it is almost stable, presenting low variations of temperature and according to previously tests, less consuming of fuel

Flux networks in metabolic graphs

A metabolic model can be represented as bipartite graph comprising linked reaction and metabolite nodes. Here it is shown how a network of conserved fluxes can be assigned to the edges of such a graph by combining the reaction fluxes with a conserved metabolite property such as molecular weight. A similar flux network can be constructed by combining the primal and dual solutions to the linear programming problem that typically arises in constraint-based modelling. Such constructions may help with the visualisation of flux distributions in complex metabolic networks. The analysis also explains the strong correlation observed between metabolite shadow prices (the dual linear programming variables) and conserved metabolite properties. The methods were applied to recent metabolic models for Escherichia coli, Saccharomyces cerevisiae, and Methanosarcina barkeri. Detailed results are reported for E. coli; similar results were found for the other organisms.Comment: 9 pages, 4 figures, RevTeX 4.0, supplementary data available (excel

C2. Pneumonia adquirida na comunidade (PAC) – influência da terapêutica com macrólidos ou novas fluoroquinolonas na evolução e duração de internamento

The need to cover atypical agents in the initial Community-Acquired Pneumonia (CAP) inpatients therapy is currently the focus of much debate. A lack of consensus in this issue might relate to regional variation in the prevalence of atypical agents. The most recent American guidelines (ATS and IDSA) suggest the use of a macrolid or a antipneumococcal fluoroquinolone in the initial empirical therapy of CAP, so that atypical agents are also always covered. This study aimed to compare the progression and length of hospitalization between CAP patients treated with a combination of a beta-lactamic antibiotic and a macrolid or a new quinolone (Group I) and other form of therapy without atypical agent coverage (Group II). A retrospective study was performed with 180 inpatients, admitted with PAC diagnosis between December 2000 and May 2002 in a general Pneumology Service. 105 (58,3%) patients were included in Group I and 75 (41,7%) in Group II. There were no statistically significant differences between the two groups regarding age, sex, clinical presentation, co morbidities or severity of the inaugural presentation. There were 14 patients with unfavourable clinical progression belonging 50% of them to Group I. The average of the length of hospital stay in Group I was 12.2 days and 13.7 days in Group II, which is also a non-significant statistical difference.Then, we may conclude that initial therapy covering atypical agents might not always be necessary. Prospective studies will be important to further address this question and to investigate the epidemiology of atypical agents of CAP in Portugal

Properties and Biodegradability of Thermoplastic Starch Obtained from Granular Starches Grafted with Polycaprolactone

Granular starches grafted with polycaprolactone (St-g-PCL) were obtained using N-methylimidazole (NMI) as a catalyst. The effect of the starch/monomer ratio and catalyst content was studied to obtain different levels of grafted PCL. The highest grafting percentage (76%) and addition (43%) were achieved for reactions with a starch/monomer ratio of 50/50 and 25% catalyst. The grafting of PCL on the starch granule was verified by the emergence of the carbonyl group in the FTIR spectra and the increased diameter of the grafted starch granule. Thermoplastic starch from ungrafted starch (TPS) and grafted starch (TPGS) was obtained by mixing ungrafted or grafted starch granules with water, glycerol, or sorbitol in a mixer. TPS and TPGS behave as plastic materials, and their mechanical properties depend on the type of plasticizer used. Materials with glycerol as the plasticizer exhibited less rigidity. The presence of starch-g-PCL results in a dramatic increase in the elongation of the thermoplastic material. The starch present in the TPS or TPGS was completely biodegraded while the grafted PCL was partially biodegraded after the enzymatic degradation of the materials