The growth rate and dimension theory of beta-expansions

In a recent paper of Feng and Sidorov they show that for β∈(1,(1+5√)/2) the set of β-expansions grows exponentially for every x∈(0,1/(β−1)). In this paper we study this growth rate further. We also consider the set of β-expansions from a dimension theory perspective.

Relative importance of transpiration rate and leaf morphological traits for the regulation of leaf temperature

Urban greening solutions such as green roofs help improve residents’ thermal comfort and building insulation. However, not all plants provide the same level of cooling. This is partially due to differences in plant structure and function, including different mechanisms that plants employ to regulate leaf temperature. Ranking of multiple leaf/plant traits involved in the regulation of leaf temperature (and, consequently, plants’ cooling ‘service’) is not well understood. We therefore investigated the relative importance of water loss, leaf colour, thickness and extent of pubescence for the regulation of leaf temperature, in the context of species for semi-extensive green roofs. Leaf temperature were measured with an infrared imaging camera in a range of contrasting genotypes within three plant genera (Heuchera, Salvia and Sempervivum). In three glasshouse experiments (each evaluating three or four genotypes of each genera) we varied water availability to the plants and assessed how leaf temperature altered depending on water loss and specific leaf traits. Greatest reductions in leaf temperature were closely associated with higher water loss. Additionally, in non-succulents (Heuchera, Salvia), lighter leaf colour and longer hair length (on pubescent leaves) both contributed to reduced leaf temperature. However, in succulent Sempervivum, colour/pubescence made no significant contribution; leaf thickness and water loss rate were the key regulating factors. We propose that this can lead to different plant types having significantly different potentials for cooling. We suggest that maintaining transpirational water loss by sustainable irrigation and selecting urban plants with favourable morphological traits is the key to maximising thermal benefits provided by applications such as green roofs.

Germination rate and sporeling development of Chondracanthus chamissoi (Rhodophyta, Gigartinales) varies along a latitudinal gradient on the coast of Chile

Chondracanthus chamissoi (C. Agardh) Kutzing is an economically important red seaweed with an extended latitudinal distribution along the south-east Pacific. Here we report on the seasonal in vitro germination of carpospores and tetraspores from four populations distributed from 27 to 41 degrees S on the Chilean coast. Our results show that both types of spores exhibited a different physiological behavior related to the geographic origin of the specimens. Germination occurred throughout the year for both spore types in the four populations. However, for the northern locations (Calderilla, La Herradura and Puerto Aldea) germination was higher in spring, while for the southern location (Lechagua), germination was higher in summer. The growth rate of carposporelings and tetrasporelings varied seasonally in ail locations studied, with higher growth in spring. Among all, carposporelings from Lechagua specimens reached the highest growth rates (9.3 +/- 0.2% d(-1)). However, spores from Herradura and P. Aldea had a good germination and SGR in all seasons and would be good candidates to start spores-based cultivation of this valuable resource in Chile. (C) 2009 Elsevier B.V. All rights reserved

T3 acutely increases GH mRNA translation rate and GH secretion in hypothyroid rats

Cytoskeleton controls the stability of transcripts, by mechanisms that involve mRNAs and eEF1A attachment to it. Besides, it plays a key role in protein synthesis and secretion, which seems to be impaired in somatotrophs of hypothyroid rats, whose cytoskeleton is disarranged. This study investigated the: eEF1A and GH mRNA binding to cytoskeleton plus GH mRNA translation rate and GH secretion, in sham-operated and thyroidectomized rats treated with T3 or saline, and killed 30 min thereafter. Thyroidectomy reduced: (a) pituitary F-actin content, and eEF1A plus GH mRNA binding to it; (b) GH mRNA recruitment to polysome; and (c) liver IGF-1 mRNA expression, indicating that GH mRNA stability and translation rate, as well as GH secretion were impaired. T3 acutely reversed all these changes, which points toward a nongenomic action of T3 on cytoskeleton rearrangement, which might contribute to the increase on GH mRNA translation rate and GH secretion. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

A Community-based Survey of Human Toxoplasmosis in Rural Amazonia: Seroprevalence, Seroconversion Rate, and Associated Risk Factors

IgG antibodies to Toxoplasma gondii were detected in, March-April 2004, in 65.8% (95% confidence interval, 60.8-70.8%) of 342 systematically sampled subjects 5-90 years of age (87.5% of the eligible) living in a rural settlement in Amazonia, with a seroconversion rate of 9% over I year of follow-up of 99 seronegative subjects. Multiple logistic regression analysis identified age as the only significant independent predictor of seropositivity at the baseline. Each additional year of age increases the odds of being seropositive by 6%, and 76.8% of the subjects are expected to be seropositive at 30 years of age. A single high-prevalence spatial cluster, comprising 11.9% of the seropositive subjects, was detected in the area; households in the cluster were less likely to have dogs as pets and their heads had a lower education level, when compared with households located outside the cluster. The challenges for preventing human toxoplasmosis in tropical rural settings are discussed.

Inflammation, oxidative stress, glomerular filtration rate, and albuminuria in elderly men : a cross-sectional study

BACKGROUND: The role of inflammation and oxidative stress in mild renal impairment in the elderly is not well studied. Accordingly, we aimed at investigating the associations between estimated glomerular filtration rate (eGFR), albumin/creatinine ratio (ACR), and markers of different inflammatory pathways and oxidative stress in a community based cohort of elderly men. FINDINGS: Cystatin C-based GFR, ACR, and biomarkers of cytokine-mediated inflammation (interleukin-6, high-sensitivity C-reactive protein[CRP], serum amyloid A[SAA]), cyclooxygenase-mediated inflammation (urinary prostaglandin F2alpha [PGF2alpha]), and oxidative stress (urinary F2 isoprostanes) were assessed in the Uppsala Longitudinal Study of Adult Men(n = 647, mean age 77 years). RESULTS: In linear regression models adjusting for age, BMI, smoking, blood pressure, LDL-cholesterol, HDL-cholesterol, triglycerides, and treatment with statins, ACE-inhibitors, ASA, and anti-inflammatory agents, eGFR was inversely associated with CRP, interleukin-6, and SAA (beta-coefficient -0.13 to -0.19, p < 0.001 for all), and positively associated with urinary F2-isoprostanes (beta-coefficient 0.09, p = 0.02). In line with this, ACR was positively associated with CRP, interleukin-6, and SAA (beta- coefficient 0.09-0.12, p < 0.02 for all), and negatively associated with urinary F2-isoprostanes (beta-coefficient -0.12, p = 0.002). The associations were similar but with lower regression coefficients in a sub-sample with normal eGFR (>60 ml/min/1.73 m2, n = 514), with the exception that F2-isoprostane and SAA were no longer associated with eGFR. CONCLUSION: Our data indicate that cytokine-mediated inflammation is involved in the early stages of impaired kidney function in the elderly, but that cyclooxygenase-mediated inflammation does not play a role at this stage. The unexpected association between higher eGFR/lower albuminuria and increased F2-isoprostanes in urine merits further studies.

What happens after the central bank of Brazil increases the target interbank rate by 1%?

I start presenting an explicit solution to Taylorís (2001) model, in order to illustrate the link between the target interest rate and the overnight interest rate prevailing in the economy. Next, I use Vector Auto Regressions to shed some light on the evolution of key macroeconomic variables after the Central Bank of Brazil increases the target interest rate by 1%. Point estimates show a four-year accumulated output loss ranging from 0:04% (whole sample, 1980 : 1-2004 : 2; quarterly data) to 0:25% (Post-Real data only) with a Örst-year peak output response between 0:04% and 1:0%; respectively. Prices decline between 2% and 4% in a 4-year horizon. The accumulated output response is found to be between 3:5 and 6 times higher after the Real Plan than when the whole sample is considered. The 95% confidence bands obtained using bias-corrected bootstrap always include the null output response when the whole sample is used, but not when the data is restricted to the Post-Real period. Innovations to interest rates explain between 4:9% (whole sample) and 9:2% (post-Real sample) of the forecast error of GDP.

Micro evidence on brazilian price stickiness and its consequences for sectoral real exchange rate and inflation persistence

The purpose of this thesis is to investigate the price-setting behavior in Brazil and, in particular, the effects on inflation and good-level real exchange rate persistence. This thesis is composed by three Chapters. In the first Chapter, we present the main stylized facts about the behavior of retail prices in Brazil using micro data from the CPI index computed by the Fundação Getulio Vargas. Moreover we construct time series of price-setting statistics and relate them to macroeconomic variables using regression analyses. In Chapter 2, we investigated the relevance of heterogeneity in countries price stickiness on good-level real exchange rate persistence, considering a newly constructed panel data set of relative prices of 115 common products between the U.S. and Brazil. Chapter 3 is devoted to the relation between sectoral price stickiness and inflation persistence.

US real interest rates and default risk in emerging economies

This paper empirically investigates the impact of changes in US real interest rates on sovereign default risk in emerging economies using the method of identification through heteroskedasticity. Policy-induced increases in US interest rates starkly raise default risk in emerging market economies. However, the overall correlation between US real interest rates and the risk of default is negative, demonstrating that the effects of other variables dominate the anterior relationship

Assessing Dodd Frank Effects on banking capital structure and Banker´s Pay structure

The systemic financial crisis that started in 2008 in the United States had some severe effects in the economic activity and required the bailout of financial institutions with the use of taxpayer’s money. It also originated claims for stronger regulatory framework in order to avoid another threat in the financial market. The Dodd Frank Act was proposed and approved in the United States in the aftermath of the crisis and brought, among many other features, the creation of the Financial Stability Oversight Council and the tougher inspection of financial institutions with asset above 50 billion dollars. The objective of this work is to study the causal effect of the Dodd Frank Act on the behavior of the treatment group subject to monitoring by the Financial Stability Oversight Council (financial institutions with assets above 50 billion dollars) regarding capital and compensation structure in comparison to the group that was not treated. We use data from Compustat and our empirical strategy is the Regression Discontinuity Design, not usually applied to the banking literature, but very useful for the present work since it allows us to compare the treatment group and the non-treatment group in the year of the enactment of the law (2010). No change of behavior was observed for the Capital Structure. In the Compensation Schemes, however, a decrease was found in the item other compensation for CEOs and CFOs. We also performed a robustness check by running a placebo test on the variables in the year before the law was enacted. No significance was found, which supports the conclusion that our main results were caused by the enactment of the DFA.

Temporal causality between the exchange rate and the trade balance : the case of Brazil

The paper assesses the impact of intemational relative prices and domestic expenditure variables on Brazil' s foreign trade performance in the first half of the 1990s. It has been argued that the appreciation of the Real since 1994 has had a detrimental impact of the country's trade balance. However, using temporal precedence analysis, our results do not indicate that the trade balance is strongly affected by intemational rei ative prices, such as the exchange rate. Instead, domestic expenditure variables appear to be more powerful determinant of the country' s trade performance in recent years. Granger and error correction causality techniques are used to determine temporal precedence between the trade balance and the exchange rate in the period under examination. Our findings shed light on the debate over the sustainability of recent exchange rate-anchored macroeconomic stabilisation programmes, which is a topic that has encouraged a lot of debate among academics and practitioners.

Sovereignty, exchange rate and the Euro crisis

This paper presents an interpretation of the European crisis based on the balance of payments imbalances within the Eurozone and highlighting the role of the “internal” real exchange rates as a primary cause of the crisis. It explores the structural contradictions that turn the Euro into a “foreign currency” for each individual Eurozone country. These contradictions imply the inability of national central banks to monetize the public and private debts, which makes the Euro crisis a sovereign crisis similar to those typical of emerging countries, but whose solution presents additional obstacles.

Brazil’s 35 years-old quasi-stagnation: facts and theory

Brazil is growing around 1% per capita a year from 1981; this means for a country that is supposed to catch up, quasi-stagnation. Four historical new facts explain why growth was so low after the Real Plan: the reduction of public savings, and three facts that reduce private investments: the end of the unlimited supply of labor, a very high interest rate, and the 1990 dismantling of the mechanism that neutralized the Dutch disease, which represented a major competitive disadvantage for the manufacturing industry. New-developmental theory offers an explanation and two solutions for the problem, but does not underestimate the political economy problems involved

Volatility of returns, variations in prices and volume traded: evidence from the main stocks in Brazil

We study the relationship between the volatility and the price of stocks and the impact that variables such as past volatility, financial gearing, interest rates, stock return and turnover have on the present volatility of these securities. The results show the persistent behavior of volatility and the relationship between interest rate and volatility. The results also showed that a reduction in stock prices are associated with an increase in volatility. Finally we found a greater trading volume tends to increase the volatility.

Some notes about the determination of current account equilibrium real exchange rate and the relation between real exchange rate and productive specialization

The objective of these notes is to present a simple mathematical model of the determination of current account real exchange rate as defined by Bresser-Pereira (2010); i.e. the real exchange rate that guarantees the inter temporal equilibrium of balance of payments and to show the relation between Real Exchange rate and Productive Specialization at theoretical and empirical level.