The Frisch elasticity in the Mercosur countries: A pseudo-panel approach

Copyright @ 2011 Brunel UniversityThis paper provides estimates for the Mercosur countries of the Frisch elasticity —i.e., the elasticity of substitution between worked hours and real wages holding constant the marginal utility of wealth—. We find a strong heterogeneity, with estimated elasticities ranging from 12.8 in Argentina to -13.1 in Paraguay. Brazil and Uruguay are in between, both with negative values of -1.9 and -1.4, respectively. We argue that the existence of severe liquidity constraints is the main reason behind the negative estimates found in Brazil, Paraguay and Uruguay. The heterogeneity of these estimates is the outcome of differences in many relevant economic dimensions —ranging from sectorial specialization to welfare state provisions and labor market specificities— all of them crucially affecting the socioeconomic situation of individuals. The diversity of Frisch elasticities calls for the development of a cross-country (rather than a within-country) policy approach, since they crucially affect the dynamics of the business cycle and business cycle synchronization is a step prior to the design of macroconvergence policies in the Mercosur context

Dual task impairments in vascular dementia

Several studies have shown that people with Alzheimer's disease (AD) demonstrate difficulties in doing two things at once or 'dual-tasking' and that this dual task impairment is insensitive to normal ageing, chronic depression or prodromal conditions like Mild Cognitive Impairment. It is not known, however, if this impairment is specific to AD, or also present in other dementias, such as vascular dementia (VaD). In this study 15 people with VaD, 25 healthy age-matched and 25 healthy young controls were assessed using a paper and pencil dual tasking paradigm and several measures of working and episodic memory. Age had no effect on dual task performance, but the VaD patients demonstrated a significant impairment in dual tasking ability. Performance on the memory measures was instead affected by age with a further deterioration in the VaD patients. Both dual tasking and memory ability were significantly correlated with disease severity, as assessed by the MMSE. These results indicate that performance on the dual task could be a specific indicator of pathological ageing

Disease Complementarities and the Evaluation of Public Health Interventions

This paper provides a theoretical and empirical investigation of the positive complementarities between disease-specific policies introduced by competing risks of mortality. The incentive to invest in prevention against one cause of death depends positively on the level of survival from other causes. This means that a specific public health intervention has benefits other than the direct medical reduction in mortality: it affects the incentives to fight other diseases so the overall reduction in mortality will, in general, be larger than that predicted by the direct medical effects. We discuss evidence of these cross-disease effects by using data on neo-natal tetanus vaccination through the Expanded Programme on Immunization of the World Health Organization.

Frequent Fire Alters Nitrogen Transformations in Ponderosa Pine Stands of the Inland Northwest

Recurrent, low-severity fire in ponderosa pine (Pinus ponderosa)linterior Douglas-fir (Pseudotsuga menziesii var. glauca) forests is thought to have directly influenced nitrogen (N) cycling and availability. However, no studies to date have investigated the influence of natural fire intervals on soil processes in undisturbed forests, thereby limiting our ability to understand ecological processes and successional dynamics in this important ecosystem of the Rocky Mountain West. Here, we tested the standing hypothesis that recurrent fire in ponderosa pine/Douglas-fir forests of the Inland Northwest decreases total soil N, but increases N turnover and nutrient availability. We compared soils in stands unburned over the past 69-130 years vs. stands exposed to two or more fires over the last 130 years at seven distinct locations in two wilderness areas. Mineral soil samples were collected from each of the seven sites in June and July of 2003 and analyzed for pH, total C and N, potentially mineralizable N (PMN), and extractable NH4+, NO3, PO4-3, Ca+2, Me, and K+. Nitrogen transformations were assessed at five sites by installing ionic resin capsules in the mineral soil in August of 2003 and by conducting laboratory assays of nitrification potential and net nitrification in aerobic incubations. Total N and PMN decreased in stands subjected to multiple fires. This loss of total N and labile N was not reflected in concentrations of extractable NH4+ and NO3-. Rather, multiple fires caused an increase in NO3- sorbed on ionic resins, nitrification potential, and net nitrification in spite of the burned stands not having been exposed to fire for at least 12-17 years. Charcoal collected from a recent fire site and added to unburned soils increased nitrification potential, suggesting that the decrease of charcoal in the absence of tire may play an important role in N transformations in fire-dependent ecosystems in the long term. Interestingly, we found no consistent effect of fire frequency on extractable P or alkaline metal concentrations. Our results corroborate the largely untested hypothesis that frequent fire in ponderosa pine forests increases inorganic N availability in the long term and emphasize the need to study natural, unmanaged sites in far greater detail

Lack of Fire Has Limited Physiological Impact on Old-Growth Ponderosa Pine in Dry Montane Forests of North-Central Idaho

Reduced frequency of fire in historically fire-adapted ecosystems may have adverse effects on ecosystem structure, function, and resilience. Lack of fire increases stand density and promotes successional replacement of seral dominant trees by late-successional, more shade-tolerant species. These changes are thought to increase competition for limited resources among trees and to increase physiological stress of dominant, fire-adapted species. However, there has been little effort to directly investigate effects of lack of fire on the physiological status of old trees, especially in unlogged, protected forests. At four remote sites in the Selway-Bitterroot region of Idaho, we tested whether the physiological status of dominant old-growth ponderosa pine trees in repeatedly burned stands (three to four 20th-century wildfires at roughly historical fire frequency) differs from trees in paired stands not burned for at least 70 years. We hypothesized that trees in relatively unburned stands would exhibit signs of physiological stress due to increased competition for resources in higher-density stands. Needle chemistry and morphological variables, fine root production, mycorrhizal infection rates, depth of soil water resources, and recent basal area growth rates were measured as indictors of competition-induced stress. Contrary to predictions, needle carbon isotopic ratio (δ13C) and fine root production, variables related to water stress, were slightly higher in repeatedly burned stands driven by site-specific responses, and there were no significant biological differences between trees in repeatedly burned stands vs. stands unburned for at least 70 years in the remaining variables. Our results raise the possibility that dominant ponderosa pine trees in uneven-aged forests may be more resilient to increased stand density associated with the lack of fire than previously thought. If so, our results have implications for the management of uneven-aged, old-growth forests

XMM-Newton observations of Nova Sgr 1998

We report on X-ray observations of Nova Sagittarius 1998 (V4633 Sgr), performed with XMM-Newton at three different epochs, 934, 1083 and 1265 days after discovery. The nova was detected with the EPIC cameras at all three epochs, with emission spanning the whole energy range from 0.2 to 10 keV. The X-ray spectra do not change significantly at the different epochs, and are well fitted for the first and third observations with a multi-temperature optically thin thermal plasma, while lower statistics in the second observations lead to a poorer fit. The thermal plasma emission is most probably originated in the shock heated ejecta, with chemical composition similar to that of a CO nova. However, we can not completely rule out reestablished accretion as the origin of the emission. We also obtain upper limits for the temperature and luminosity of a potential white dwarf atmospheric component, and conclude that hydrogen burning had already turned-off by the time of our observations.Comment: 18 pages, 3 figures. Accepted in Astrophysical Journa

Inquiry on Perceptions and Practices of Built Environment Professionals Regarding Regenerative and Circular Approaches

The circular economy and regenerative design approaches, although still emerging in the built environment, are important pathways to move away from the degenerative business-as-usual practices in the sector. In this paper, we investigate the perception, awareness, and practices of built environment professionals regarding the adoption of a combined regenerative circularity approach for buildings and cities, and if current practices and ‘neighbourhood sustainability assessment’ (NSA) tools should be improved and how. The inquiry was conducted using a convergent mixed methods approach with professionals from around the globe through: (a) online questionnaires which collected 146 responses, and (b) 18 semi-structured interviews which delved further into relevant aspects of the survey. Quantitative and qualitative responses were coded, grouped, and analysed. Results indicate an average awareness of topics with large space for improvement of practices. The main pathways for improvement for NSA tools include performance requirements, aspects of flexibility and adaptability, and engagement and communication, to which are added opportunities and enablers to improve the sector. The authors hope that this study will contribute towards the improvement and design of better tools and practices to support the implementation of regenerative circularity in the built environment sector

A Future-Proof Built Environment through Regenerative and Circular Lenses—Delphi Approach for Criteria Selection

Despite the increasing use of neighbourhood sustainability assessment tools (NSAT), their linear approach may be insufficient to tackle the global and local social and ecological challenges. The circular economy (CE) has recently emerged as a new pathway, adopted by corporations and public organisations. Understanding how to apply CE to existing communities, while addressing some of its shortcomings, particularly the strong focus on resource management, is the main goal of this paper. Building upon a Regenerative Circularity for the Built Environment (RC4BE) conceptual model that merges circular economy and regenerative design concepts, a framework with criteria for its implementation in the transition of existing urban areas is proposed. A preliminary framework structure with criteria mapped from literature is proposed and validated through a 2-round Delphi consultation with 31 international experts. The final framework, with 136 criteria, addresses some of the identified gaps and different urban cycles related to physical resources, ecosystems, liveability, infrastructure, governance, participation, local economy, and other socioeconomic aspects of urban communities. This expanded take on CE should be useful for built environment professionals and other urban stakeholders interested in regenerating their communities and precincts by going beyond current green approaches and existing tools to effectively generate positive impact for people and the planet

A neighbourhood-scale conceptual model towards regenerative circularity for the built environment

There is potential in applying the circular economy (CE) and regenerative design (RD) models for the redevelopment of urban areas as a response to the current linear and mechanistic practices that still contribute to exceeding planetary boundaries and reinforcing social inequalities. Despite these models' common roots, they are usually approached quite differently. A merged approach may be able to solve existing gaps and critiques. This paper reviews relevant CE and RD definitions linked to the urban context. An inductive content analysis to map and discuss existing themes is conducted, leading to a set of five underpinning pillars. The resulting ‘Regenerative Circularity for the Built Environment’ conceptual model adopts a systemic and positive impact approach that is the steppingstone for the development of a practical tool aiming to support urban stakeholders in the transition of existing neighbourhoods with strategies more suitable to their aims and notion of place

Temperature dependence of iron local magnetic moment in phase-separated superconducting chalcogenide

We have studied local magnetic moment and electronic phase separation in superconducting K$_{x}$Fe$_{2-y}$Se$_2$ by x-ray emission and absorption spectroscopy. Detailed temperature dependent measurements at the Fe K-edge have revealed coexisting electronic phases and their correlation with the transport properties. By cooling down, the local magnetic moment of Fe shows a sharp drop across the superconducting transition temperature (T$_c$) and the coexisting phases exchange spectral weights with the low spin state gaining intensity at the expense of the higher spin state. After annealing the sample across the iron-vacancy order temperature, the system does not recover the initial state and the spectral weight anomaly at T$_c$ as well as superconductivity disappear. The results clearly underline that the coexistence of the low spin and high spin phases and the transitions between them provide unusual magnetic fluctuations and have a fundamental role in the superconducting mechanism of electronically inhomogeneous K$_{x}$Fe$_{2-y}$Se$_2$ system.Comment: 6 pages, 5 figure