The global role of kidney transplantation

World Kidney Day on March 8 th 2012 provides a chance to reflect on the success of kidney transplantation as a therapy for end stage kidney disease that surpasses dialysis treatments both for the quality and quantity of life that it provides and for its cost effectiveness. Anything that is both cheaper and better, but is not actually the dominant therapy, must have other drawbacks that prevent replacement of all dialysis treatment by transplantation. The barriers to universal transplantation as the therapy for end stage kidney disease include the economic limitations which, in some countries place transplantation, appropriately, at a lower priority than public health fundamentals such as clean water, sanitation and vaccination. Even in high income countries the technical challenges of surgery and the consequences of immunosuppression restrict the number of suitable recipients, but the major finite restrictions on kidney transplantation rates are the shortage of donated organs and the limited medical, surgical and nursing workforces with the required expertise. These problems have solutions which involve the full range of societal, professional, governmental and political environments. World Kidney Day is a call to deliver transplantation therapy to the one million people a year who have a right to benefit

Dynamic fleet-based life-cycle greenhouse gas assessment of the introduction of electric vehicles in the Portuguese light-duty fleet

Purpose Reducing greenhouse gas (GHG) emissions from the transportation sector is the goal of several current policies and battery electric vehicles (BEVs) are seen as one option to achieve this goal. However, the introduction of BEVs in the fleet is gradual and their benefits will depend on how they compare with increasingly more energy-efficient internal combustion engine vehicles (ICEVs). The aim of this article is to assess whether displacing ICEVs by BEVs in the Portuguese light-duty fleet is environmentally beneficial (focusing on GHG emissions), taking into account the dynamic behavior of the fleet. Methods A dynamic fleet-based life-cycle assessment (LCA) of the Portuguese light-duty fleet was performed, addressing life-cycle (LC) GHG emissions through 2030 across different scenarios. A model was developed, integrating: (i) a vehicle stock sub-model of the Portuguese light-duty fleet; and (ii) dynamic LC sub-models of three vehicle technologies (gasoline ICEV, diesel ICEV and BEV). Two metrics were analyzed: (i) Total fleet LC GHG emissions (in Mton CO2 eq); and (ii) Fleet LC GHG emissions per kilometer (in g CO2 eq/km). A sensitivity analysis was performed to assess the influence of different parameters in the results and ranking of scenarios. Results and discussion The model baseline projected a reduction of 30–39 % in the 2010–2030 fleet LC GHG emissions depending on the BEV fleet penetration rate and ICEV fuel consumption improvements. However, for BEV introduction in the fleet to be beneficial compared to an increasingly more efficient ICEV fleet, a high BEV market share and electricity emission factor similar or lower to the current mix (485 g CO2 eq/kWh) need to be realized; these conclusions hold for the different conditions analyzed. Results were also sensitive to parameters that affect the fleet composition, such as those that change the vehicle stock, the scrappage rate, and the activity level of the fleet (11–19 % variation in GHG emissions in 2030), which are seldom assessed in the LCA of vehicles. The influence of these parameters also varies over time, becoming more important as time passes. These effects can only be captured by assessing Total fleet GHG emissions over time as opposed to the GHG emissions per kilometer metric. Conclusions These results emphasize the importance of taking into account the dynamic behavior of the fleet, technology improvements over time, and changes in vehicle operation and background processes during the vehicle service life when assessing the potential benefits of displacing ICEVs by BEVs.MIT-Portugal ProgramFonds Europeen de Developpement Economique et Regional (FEDER, Programa Operacional Factores de Competitividade--COMPETE)Fundação para a Ciência e a Tecnologia (Portugal) (project grant FCOMP-01-0124-FEDER-029055 (PTDC/EMS-ENE/1839/2012))Fundação para a Ciência e a Tecnologia (Portugal) (project grant FCOMP-01-0124-FEDER-021495 (PTDC/SEN-TRA/117251/2010))Fundação para a Ciência e a Tecnologia (Portugal) (project grant CENTRO-07-0224-FEDER-002004)Fundação para a Ciência e a Tecnologia (Portugal) (doctoral grant SFRH/BD/51299/2010

Optimizing Ground-based Observations of O2 in Earth Analogs

We present the result of calculations to optimize the search for molecular oxygen (O2) in Earth analogs transiting around nearby, low-mass stars using ground-based, high-resolution, Doppler shift techniques. We investigate a series of parameters, namely spectral resolution, wavelength coverage of the observations, and sky coordinates and systemic velocity of the exoplanetary systems, to find the values that optimize detectability of O2. We find that increasing the spectral resolution of observations to R = 300,000 - 400,000 from the typical R ~ 100,000, more than doubles the average depth of O2 lines in planets with atmospheres similar to Earth's. Resolutions higher than about 500,000 do not produce significant gains in the depths of the O2 lines. We confirm that observations in the O2 A-band are the most efficient except for M9V host stars, for which observations in the O2 NIR-band are more efficient. Combining observations in the O2 A, B, and NIR -bands can reduce the number of transits needed to produce a detection of O2 by about 1/3 in the case of white noise limited observations. However, that advantage disappears in the presence of typical levels of red noise. Therefore, combining observations in more than one band produces no significant gains versus observing only in the A-band, unless red-noise can be significantly reduced. Blending between the exoplanet's O2 lines and telluric O2 lines is a known problem. We find that problem can be alleviated by increasing the resolution of the observations, and by giving preference to targets near the ecliptic.Comment: 15 pages, 7 figures, accepted for publication in The Astronomical Journa

Managing coastal environments under climate change: pathways to adaptation

This paper deals with the question of how to manage vulnerable coastal systems so as to make them sustainable under present and future climates. This is interpreted in terms of the coastal functionality, mainly natural services and support for socio-economic activities. From here we discuss how to adapt for long term trends and for short terms episodic events using the DPSIR framework. The analysis is presented for coastal archetypes from Spain, Ireland and Romania, sweeping a range of meteo-oceanographic and socio-economic pressures, resulting in a wide range of fluxes among them those related to sediment. The analysis emphasizes the variables that provide a higher level of robustness. That means mean sea level for physical factors and population density for human factors. For each of the studied cases high and low sustainability practices, based on stakeholders preferences, are considered and discussed. This allows proposing alternatives and carrying out an integrated assessment in the last section of the paper. This assessment permits building a sequence of interventions called adaptation pathway that enhances the natural resilience of the studied coastal systems and therefore increases their sustainability under present and future conditions.Peer ReviewedPostprint (author's final draft

Lazy Evaluation and Delimited Control

The call-by-need lambda calculus provides an equational framework for reasoning syntactically about lazy evaluation. This paper examines its operational characteristics. By a series of reasoning steps, we systematically unpack the standard-order reduction relation of the calculus and discover a novel abstract machine definition which, like the calculus, goes "under lambdas." We prove that machine evaluation is equivalent to standard-order evaluation. Unlike traditional abstract machines, delimited control plays a significant role in the machine's behavior. In particular, the machine replaces the manipulation of a heap using store-based effects with disciplined management of the evaluation stack using control-based effects. In short, state is replaced with control. To further articulate this observation, we present a simulation of call-by-need in a call-by-value language using delimited control operations

Effects of Acute Cold Exposure on Plasma Biomarkers Associated with Cardiovascular Disease Risk

Background and Aims: The underlying cause of the majority of the cases of CVD is atherosclerosis, which is a condition initiated and progressed by chronic inflammation and hyperlipidemia. We are interested in evaluating the efficacy of cold-exposure to increase shivering- and non-shivering thermogenesis energy expenditure (RMR) as a non-pharmaceutical weight loss tool analogous to low intensity exercise. Naturally, we are concurrently evaluating the possible effects of cold exposure on risk factors associated with CVD risk. Inflammatory cytokines and lipid mediators are used as biomarkers for CVD risk. This proposed study aims to measure cardiovascular inflammatory and lipid biomarkers to expand our knowledge of cold exposure and CVD risk. The two biomarkers collected during this study were Interleukin-1 Beta (IL-β) and Chemokine Ligand 2 (CCL2). The hypothesis was that there would be no change in biomarker values before and after cold exposure. Methods: Twenty subjects were recruited and subjected to a 30-min cold exposure test while a metabolic cart collected metabolic data via indirect calorimetry. Venous plasma collected at: pre cold exposure, immediately after cold exposure, and 2 hours post cold exposure was centrifuged for subsequent biomarkers analysis. Results: RMR increases dramatically during acute cold exposure during shivering and remains increased 5 minutes after the cessation of shivering. Five minutes post-cold exposure, RMR rapidly decreases to pre-cold exposure RMR and is maintained for up to 120 minutes. There was no change in CCL2 values when comparing the three stages. IL-β values increased between blood draws immediately after cold exposure and 2 hours post cold exposure, however this increase was not statistically significant. Conclusions: With these pilot results, we conclude that cold exposure has no effect on biomarkers for CVD risk. However, this study was limited by 1) accuracy of analysis techniques, 2) cold exposure protocol, 3) analysis of only two representative biomarkers. Further biomarker analysis is underway for a more comprehensive picture of the purported cold exposure effects

Que estratégia de amostragem para os estados larvares de Mythimna unipuncta (Haworth) (Lepidoptera, Noctuidae)?

IX Expedição Científica do Departamento de Biologia - Terceira 1994A amostragem dos estados larvares de Mythimna unipuncta (Haworth) (Lepidoptera, Noctuidae), praga das pastagens dos Açores, é importante para o estudo da dinâmica populacional, bem como para a definição das regras de decisão quanto à aplicação de medidas fitossanitárias. Durante a "Expedição Científica Terceira 94", foram realizadas amostragens directas dos estados larvares de M. unipuncta em duas parcelas de pastagem, uma em São Bartolomeu e outra na Granja, através da contagem do número de larvas em 100 amostras de 0,25 m2 cada. 0 número médio de larvas observado por unidade de amostragem foi de 2,9±0,53 e de 0,98±0,21, respectivamente, em São Bartolomeu e na Granja. Usando a Lei de Taylor, o número de amostras requerido para um grau de precisão de 0.2 foi de 76 em São Bartolomeu e de 73 na Granja. O número de 20 amostras, realizadas habitualmente no estudo da abundância de larvas, proporcionou apenas uma precisão de 0,4. Porém, a distribuição das larvas ajustou-se a uma binomial negativa em ambas as localidades. A estratégia de amostragem sequencial de Wald permite a diminuição do esforço de amostragem, mas sem reduzir contudo o grau de precisão requerido pelo processo de tomada de decisão.ABSTRACT: Mythimna unipuncta (Haworth) (Lepidoptera, Noctuidae) is an important pest in Azorean pastures, so accurate estimates of larval densities are essential for population dynamic studies and for the decision making process concerning potential pesticide applications. During the "Terceira 94 Scientific Expedition" we determined the efficiency of our standard estimates of larval densities, derived from 20 0,25 m2 samples, with those obtained using 100 samples. This was replicated at two different sites, São Bartolomeu (where larval densities were 2,9±0,53 per sample unit) and Granja (with larval densities of 0,98±0,21). Using Taylor's power law the number of samples required for a 0,2 level of precision was 76 in São Bartolomeu and 73 in Granja, and the usual number of samples (20) only provided a precision of 0,4. However, as larval distribution fitted a negative binomial distribution at both sites, a sequential sampling might lower sampling effort without reducing the level of precision required for the decision making process