Modeling usage of medical care services: the medical expenditure panel survey data, 1996-2000

We explore the determinants of usage of six different types of health care services, using the Medical Expenditure Panel Survey data, years 1996-2000. We apply a number of models for univariate count data, including semiparametric, semi-nonparametric and finite mixture models. We find that the complexity of the model that is required to fit the data well depends upon the way in which the data is pooled across sexes and over time, and upon the characteristics of the usage measure. Pooling across time and sexes is almost always favored, but when more heterogeneous data is pooled it is often the case that a more complex statistical model is required.

Consumption externalities, habit formation, and equilibrium efficiency

We analyze the welfare properties of the competitive equilibrium in a capital accumulation model where individual preferences are subjected to both habit formation and consumption spillovers. We also discuss how consumption externalities and habits interact to generate an inefficient dynamic equilibrium. Finally, we characterize optimal tax policies aimed to restore efficient decentralized paths.

Income taxation with habit formation and consumption externalities

We analyze the dynamic behavior and the welfare properties of the equilibrium path of a growth model where both habits and consumption externalities affect the utility of consumers. We discuss the effects of flat rate income taxes and characterize the optimal income taxation policy. We show that, when consumption externalities and habit adjusted consumption are not perfect substitutes, a counter-cyclical income tax rate allows the competitive equilibrium to replicate the efficient path. Our analysis highlights the crucial role played by complementarities between externalities and habits in order to generate an inefficient dynamic equilibrium.

Methodological note about the determination of key sectors in final energy consumption: a preliminary approach to the Spanish case

In this paper we analyze the determination of "key" sectors in the final energy consumption. We approach this issue from an input-output perspective and we design a methodology based on the elasticities of the demands of final energy consumption. As an exercise, we apply the proposed methodology to the Spanish economy. The analysis allows us to indicate the greater or lesser relevance of the different sectors in the consumption of final energy, pointing out which sectors deserve greater attention in the Spanish case and showing the implications for energy policy.

Income growth and atmospheric pollution in Spain: an input-output approach

The relationships between economic growth and environmental pressures are complex. Since the early nineties, the debate on these relationships has been strongly influenced by the Environmental Kuznets Curve hypothesis, which states that during the first stage of economic development environmental pressures increase as per capita income increases, but once a critical turning-point has been reached these pressures diminish as income levels continue to increase. However, to date such a delinking between economic growth and emission levels has not happened for most atmospheric pollutants in Spain. The aim of this paper is to analyse the relationship between income growth and nine atmospheric pollutants in Spain. In order to obtain empirical outcomes for this analysis, we adopt an input-output approach and use NAMEA data for the nine pollutants. First, we undertake a structural decomposition analysis for the period 1995-2000 to estimate the contribution of various factors to changes in the levels of atmospheric emissions. And second, we estimate the emissions associated with the consumption patterns of different groups of households classified according to their level of expenditure

Studies on Trypanosoma rangeli Tejera, 1920: V - Developmental pattern in the alimentary canal of Rhodnius prolixus

The morphological sequence of Trypanosoma rangeli development in the alimentary canal of Rhodnius prolixus, is described, with observation made in dissected guts from 6 hours to 45 days post-infection. No metacyclic-forms are produced in the digestive tract at any time, and transmission by the contaminative route must be considered atypical. Amastigotes appear to be an essential stage in the development of T. rangeli in the gut of R. prolixus. The epidemiological importance of the developmental pattern of T. rangeli in the vector´s gut is discussed, and its usefulness for aging infection is considered.

Studies on Trypanosoma rangeli Tejera 1920: VI. Developmental pattern in the haemolymph of Rhodnius prolixus

The morphological sequence of Trypanosoma rangeli development in the body cavity of Rhodnius prolixus is described. The metacyclic trypanosome is the product of successive division and transformation during the intra and extracellular development in the haemocoele. The significance of the early invasion of T. rangeli into the haemolymph is discussed. The epidemiological importance of the developmental pattern of T. rangeli in the vectors haemolymph and the host-response to the parasite are considered.

The changing pattern of pathology due to Schistosoma mansoni infection

A survey of the autopsy data on hepatosplenic schistosomiasis during periods, before and after the advent of new chemotherapeutic drugs, revealed that: a) the pathological presentation was the same for the two periods; b) the number of cases in the last five years is progressively decreasing; c) hepatosplenic disease due to schistosomiasis is becoming rare in young people. These data represent a change in the pattern of pathology in schistosomiasis, probably related to new chemotherapy.

The biophysical perspective of a middle income economy: material flows in Mexico

We analyse natural resource use dynamics in the Mexican economy during the last three decades. Despite low and uneven economic growth, the extraction and use of materials in the Mexican economy has continuously increased during the last 30 years. In this period, population growth rather than economic growth was the main driving force for biophysical growth. In addition, fundamental changes have taken place in the primary sectors, in manufacturing, and in household consumption and these are reflected in an increasing emphasis on the use of fossil fuels and construction materials. Mexico’s economy has been strongly influenced by international trade since the country commenced competing in international markets. In the 1970s, Mexico mainly exported primary resources. This pattern has changed and manufactured goods now have a much greater importance due to a boom in assembling industries. In contrast with other Latin American countries, Mexico has achieved a diversification of production, moving towards technology-intensive products and a better mix in its export portfolio. However, crude oil exports still represent the single most important export good. Mexico’s material consumption is still well below the OECD average but is growing fast and the current resource use patterns may well present serious social and environmental problems to the medium and long term sustainability of Mexico’s economy and community. Information on natural resource use and resource productivity could provide valuable guidance for economic policy planning in Mexico.

New measurements of energy expenditure and physical activity in chronic kidney disease.

The accurate estimation of total daily energy expenditure (TEE) in chronic kidney patients is essential to allow the provision of nutritional requirements; however, it remains a challenge to collect actual physical activity and resting energy expenditure in maintenance dialysis patients. The direct measurement of TEE by direct calorimetry or doubly labeled water cannot be used easily so that, in clinical practice, TEE is usually estimated from resting energy expenditure and physical activity. Prediction equations may also be used to estimate resting energy expenditure; however, their use has been poorly documented in dialysis patients. Recently, a new system called SenseWear Armband (BodyMedia, Pittsburgh, PA) was developed to assess TEE, but so far no data have been published in chronic kidney disease patients. The aim of this review is to describe new measurements of energy expenditure and physical activity in chronic kidney disease patients.

Secondary effects of catalytic diesel particulate filters: copper-induced formation of PCDD/Fs.

Potential risks of a secondary formation of polychlorinated dibenzodioxins/furans (PCDD/Fs) were assessed for two cordierite-based, wall-through diesel particulate filters (DPFs) for which soot combustion was either catalyzed with an iron- or a copper-based fuel additive. A heavy duty diesel engine was used as test platform, applying the eight-stage ISO 8178/4 C1 cycle. DPF applications neither affected the engine performance, nor did they increase NO, NO2, CO, and CO2 emissions. The latter is a metric for fuel consumption. THC emissions decreased by about 40% when deploying DPFs. PCDD/F emissions, with a focus on tetra- to octachlorinated congeners, were compared under standard and worst case conditions (enhanced chlorine uptake). The iron-catalyzed DPF neither increased PCDD/F emissions, nor did it change the congener pattern, even when traces of chlorine became available. In case of copper, PCDD/F emissions increased by up to 3 orders of magnitude from 22 to 200 to 12 700 pg I-TEQ/L with fuels of < 2, 14, and 110 microg/g chlorine, respectively. Mainly lower chlorinated DD/Fs were formed. Based on these substantial effects on PCDD/F emissions, the copper-catalyzed DPF system was not approved for workplace applications, whereas the iron system fulfilled all the specifications of the Swiss procedures for DPF approval (VERT).

New FFT/IFFT Factorizations with Regular Interconnection Pattern Stage-to-Stage Subblocks

Les factoritzacions de la FFT (Fast Fourier Transform) que presenten un patró d’interconnexió regular entre factors o etapes son conegudes com algorismes paral·lels, o algorismes de Pease, ja que foren originalment proposats per Pease. En aquesta contribució s’han desenvolupat noves factoritzacions amb blocs que presenten el patró d’interconnexió regular de Pease. S’ha mostrat com aquests blocs poden ser obtinguts a una escala prèviament seleccionada. Les noves factoritzacions per ambdues FFT i IFFT (Inverse FFT) tenen dues classes de factors: uns pocs factors del tipus Cooley-Tukey i els nous factors que proporcionen la mateix patró d’interconnexió de Pease en blocs. Per a una factorització donada, els blocs comparteixen dimensions, el patró d’interconnexió etapa a etapa i a més cada un d’ells pot ser calculat independentment dels altres.

Metabolic and respiratory effects of infused sodium acetate in healthy human subjects.

The metabolic and respiratory effects of intravenous 0.5 M sodium acetate (at a rate of 2.5 mmol/min during 120 min) were studied in nine normal human subjects. O2 consumption (VO2) and CO2 production (VCO2) were measured continuously by open-circuit indirect calorimetry. VO2 increased from 251 +/- 9 to 281 +/- 9 ml/min (P < 0.001), energy expenditure increased from 4.95 +/- 0.17 kJ/min baseline to 5.58 +/- 0.16 kJ/min (P < 0.001), and VCO2 decreased nonsignificantly (211 +/- 7 ml/min vs. 202 +/- 7 ml/min, NS). The extrapulmonary CO2 loss (i.e., bicarbonate generation and excretion) was estimated at 48 +/- 5 ml/min. This observation is consistent with 1 mol of bicarbonate generated from 1 mol of acetate metabolized. Alveolar ventilation decreased from 3.5 +/- 0.2 l/min basal to 3.1 +/- 0.2 l/min (P < 0.001). The minute ventilation (VE) to VO2 ratio decreased from 22.9 +/- 1.3 to 17.6 +/- 0.9 l/l (P < 0.005), arterial PO2 decreased from 93.2 +/- 1.9 to 78.7 +/- 1.6 mmHg (P < 0.0001), arterial PCO2 increased from 39.2 +/- 0.7 to 42.1 +/- 1.1 mmHg (P < 0.0001), pH from 7.40 +/- 0.005 to 7.50 +/- 0.007 (P < 0.005), and arterial bicarbonate concentration from 24.2 +/- 0.7 to 32.9 +/- 1.1 (P < 0.0001). These observations indicate that sodium acetate infusion results in substantial extrapulmonary CO2 loss, which leads to a relative decrease of total and alveolar ventilation.