Álvaro Aguiar

Testing for Asymmetries in the Preferences of the Euro-Area Monetary Policymaker

This article tests for asymmetries in the preferences of the euro-area monetary policymaker with 1995:1–2005:2 data from the latest update of the European Central Banks (ECBs) Area-wide database. Following the relevant literature, we distinguish between three types of asymmetry: precautionary demand for expansions, precautionary demand for price stability and interest rate smoothing asymmetry. Based on the joint generalized method of moments (GMM) estimation of the Euler equation of optimal policy and the aggregate supply-aggregate demand (AS-AD) structure of the macroeconomy, we find evidence of precautionary demand for price stability in the preferences revealed by the monetary policymaker. This type of asymmetry is consistent with the ECBs definition of price stability and with the priority of credibility-building by a recently created monetary authority. 1CEMPRE–Centro de Estudos Macroeconómicos e Previsão - is a research centre supported by the Fundação para a Ciência e a Tecnologia, Portugal, which is financed by European Union and Portuguese funds.

Macroeconomic Volatility Trade-off and Monetary Policy Regime in the Euro Area

This research uncovers a well-defined monetary policy regime starting in 1986 in the aggregate Euro Area. Both alternative solution-estimation methods employed - optimal control cum GMM, and dynamic programming cum FIML - identify a regime of strict inflation targeting with interest rate smoothing. The unemployment gap, properly estimated as quasi real-time information, is a relevant element in the information set of the monetary authority, despite not being included in its preferences. The emergence of the regime relates to the improvement of the volatility trade-off between inflation and unemployment gap since the mid-80s. Additional improving factors have been milder supply shocks and better ability of policymakers to set the interest rate closer to optimum.

Trend, cycle, and non-linear trade-off in the Euro Area 1970-2001

This paper presents new tests and estimates of the Phillips trade-off in the Euro Area, carried out in a unobserved components model with possibly non-linear Phillips and Okun relations, using quarterly aggregate data for the period 1970:I-2001:II. A concept of forward-looking near-rational expectations is introduced in the model, improving on the contradiction between rational expectations and evidence of inflation inertia. The Phillips curve turns out to be linear and its trade-off statistically significant, while non-linearity shows up in the Okun relation. The trend-cycle decompositions capture the main features of the Euro Area recent macroeconomic record.

Analysis of the allelic diversity of a (CA)n repeat polymorphism among α1-antitrypsin gene products from northern Portugal

Abstract The level of molecular heterogeneity associated with α1-antitrypsin gene products was assessed in the population of northern Portugal using three restriction fragment length polymorphisms (RFLPs) corresponding to specific amino acid substitutions and a highly variable (CA)n repeat polymorphism located at the 5′ end of the PI gene. The allelic affinities inferred from the analysis of the DNA polymorphisms essentially agree with the evolutionary pattern proposed for the PI gene products on the basis of their amino acid sequences. PI*Z can be considered the most recent common PI allele and was found to be associated with the same predominant haplotype previously reported in northern European populations, thus confirming the hypothesis that most European Z alleles are derived from a single mutation. However, a rare deficient variant that is the likely result of a recurrent Z mutation on an M2 or M4 background was additionally observed. PI*S was also found to be associated with a strongly predominant haplotype and seems to be the second most recent PI common allele, while M2 and M3 show weaker associations, suggesting more ancient origins of their corresponding mutations. M1Ala213 and M1Val213 display more homogeneous (CA)n allele frequency distributions, M1Ala213 representing the most ancient PI allele as inferred from its highest variance in (CA)n allele length.

Pos-infectious bronchiolitis obliterans in children

Bronchiolitis obliterans (BO) is a rare disease in immunocompetent children that usually occurs after infection of the lower airways. While a diagnosis of BO was usually confirmed by lung biopsy, identification of prior lung lesion plus a typical clinical course and a suggestive chest X-ray and CT scan have replaced the need for more invasive procedures. The authors reviewed the clinical records of 10 BO patients, followed in the Outpatients Paediatric Pulmonology Unit from January 1997 to December 2002, to identify the most common aetiology, clinical and radiological profiles, treatment and course. All patients maintained cough and/or wheezing after the initial acute episode. 80% had failure to thrive at the time of the diagnosis, mean age 16 months. Viral pneumonia was the main initial event (5 adenovirus, 3 respiratory syncytial virus, 1 parainfluenza virus, 1 unknown). Lung biopsies were not performed as clinical and radiological presentations were typical of BO. The follow-up (mean 36 months) revealed clinical resolution in 3 children and persistent symptoms in 6. One patient had progressive respiratory failure and died. Prompt recognition of the diagnosis with supportive treatment that included oxygen therapy and an aggressive nutrition plan helped to improve the clinical state of the children.

Bony density in adolescents after surgical repair of tetralogy of fallot: a comparative study with healthy adolescents.

BACKGROUND Adverse influences arising in fetal life or immediately after birth have a permanent effect on body structure, physiology and metabolism. Evidence is now accumulating that programming of bone growth might be an important contributor to the later risk of osteoporosis. Long-term morbidity and mortality associated with retralogy of Fallot is not completely known. The aim of the present study was to evaluate the state of the bones in adolescents after surgical repair of tetralogy of Fallot, so as to ascertain any possible repercussions of the disease on bone mineralization. MATERIAL AND METHODS We studied 34 adolescents with repaired tetralogy of Fallot, between the ages of 11 and 18 years, to establish their nutritional status, in terms of height, weight, and skinfolds, their body composition using an anthropometric method, their sexual maturity according to Tanner, and their food-habits as based on 24-hour recall. Bone density was evaluated by lumbar dual-energy X-ray absorptiometry. We included 34 healthy eutrophic adolescents, matched for gender and age, as controls. RESULTS No significant differences were observed between the patients and their controls concerning nutritional status, body composition, total energy intake and nutritional supply in macronutrients, calcium, phosphorus, magnesium and vitamin D. Bone mineral density, expressed in Z-score and g/cm2, was significantly higher in patients with tetralogy of Fallot (p < 0.01). The age at the time of the first surgical procedure, or at complete surgical repair, and the total number of surgical procedures, had no significant influence on nutritional status or bone mineralization. Gender, chronological age, sexual maturity and the index of body mass are the major determinants of bone density for both samples. Obese adolescents with repaired tetralogy of Fallot had a significantly higher bone density (p < 0.05) compared to undernourished or euthrophic patients. CONCLUSIONS Being born with tetralogy of Fallot has no significant repercussion, by the stage of adolescence, on nutritional status, pubertal progression, and accretion of bone minerals subsequent to surgical repair. Nutritional status is the major influence on the accretion of bone mass.

Polymorphism C242T of the gene of the p22phox subunit for nicotinamide adenine dinucleotide phosphate oxidase, and erythrocytic antioxidant enzymes, in patients with tetralogy of Fallot.

BACKGROUND Nicotinamide adenine dinucleotide phosphate oxidase of the vascular cell membrane is an important source of reactive oxygen species. The aim of our study was to evaluate the possible influence of the p22phox C242T gene polymorphism on blood pressure and some markers of oxidative stress in children with tetralogy of Fallot. METHODS After surgical repair in early life, we recruited 38 children, aged 11.7 plus or minus 3.2 years, including 185 healthy individuals as controls for the purposes of establishing frequencies of alleles and genotypes. From this latter group, we matched a sub-sample of 53 healthy caucasian children, aged 11.0 plus or minus 1.0 years, in order to compare enzymic activities. RESULTS The children with tetralogy of Fallot showed significantly lower values of low-molecular-weight protein tyrosine phosphatase, particularly in carriers of CC genotype for the p22phox gene, with values of 145.2 plus or minus 77.4 micromol/g Hb/h, compared to controls, at 344.4 plus or minus 100.4 micromol/g Hb/h (p less than 0.001). Methemoglobin reductase activity in the patients with tetralogy was also lower in those with the CC genotype, at 9.8 plus or minus 3.2 micromol/g Hb-1 min(-1) compared to 24.2 plus or minus 11.8 micromol/g Hb(-1) min(-1) as measured in the controls (p less than 0.01). Lower systolic (p less than 0.05) and diastolic (p less than 0.01) blood pressures were also observed in the patients with tetralogy of Fallot. CONCLUSIONS Patients with tetralogy of Fallot having the CC genotype may be at a higher state of oxidative stress than T allele carriers, a finding which could have prognostic implications. Long term follow-up of these patients, however, may be necessary in order to draw definite conclusions.