Mean-field theory of temperature cycling experiments in spin-glasses

We study analytically the effect of temperature cyclings in mean-field spin-glasses. In accordance with real experiments, we obtain a strong reinitialization of the dynamics on decreasing the temperature combined with memory effects when the original high temperature is restored. The same calculation applied to mean-field models of structural glasses shows no such reinitialization, again in accordance with experiments. In this context, we derive some relations between experimentally accessible quantities and propose new experimental protocols. Finally, we briefly discuss the effect of field cyclings during isothermal aging.Comment: Some misprints corrected, references updated, final version to apper in PR

Real-time non-equilibrium dynamics of quantum glassy systems

We develop a systematic analytic approach to aging effects in quantum disordered systems in contact with an environment. Within the closed-time path-integral formalism we include dissipation by coupling the system to a set of independent harmonic oscillators that mimic a quantum thermal bath. After integrating over the bath variables and averaging over disorder we obtain an effective action that determines the real-time dynamics of the system. The classical limit yields the Martin-Siggia-Rose generating functional associated to a colored noise. We apply this general formalism to a prototype model related to the $p$ spin-glass. We show that the model has a dynamic phase transition separating the paramagnetic from the spin-glass phase and that quantum fluctuations depress the transition temperature until a quantum critical point is reached. We show that the dynamics in the paramagnetic phase is stationary but presents an interesting crossover from a region controlled by the classical critical point to another one controlled by the quantum critical point. The most characteristic property of the dynamics in a glassy phase, namely aging, survives the quantum fluctuations. In the sub-critical region the quantum fluctuation-dissipation theorem is modified in a way that is consistent with the notion of effective temperatures introduced for the classical case. We discuss these results in connection with recent experiments in dipolar quantum spin-glasses and the relevance of the effective temperatures with respect to the understanding of the low temperature dynamics.Comment: 56 pages, Revtex, 17 figures include

The impact of outdoor pollution and extreme temperatures on asthma-related outcomes: a systematic review for the EAACI guidelines on environmental science for allergic diseases and asthma

Air pollution is one of the biggest environmental threats for asthma. Its impact is augmented by climate change. To inform the recommendations of the EAACI Guidelines on the environmental science for allergic diseases and asthma, a systematic review (SR) evaluated the impact on asthma-related outcomes of short-term exposure to outdoor air pollutants (PM2.5, PM10, NO2, SO2, O3, and CO), heavy traffic, outdoor pesticides, and extreme temperatures. Additionally, the SR evaluated the impact of the efficacy of interventions reducing outdoor pollutants. The risk of bias was assessed using ROBINS-E tools and the certainty of the evidence by using GRADE. Short-term exposure to PM2.5, PM10, and NO2 probably increases the risk of asthma-related hospital admissions (HA) and emergency department (ED) visits (moderate certainty evidence). Exposure to heavy traffic may increase HA and deteriorate asthma control (low certainty evidence). Interventions reducing outdoor pollutants may reduce asthma exacerbations (low to very low certainty evidence). Exposure to fumigants may increase the risk of new-onset asthma in agricultural workers, while exposure to 1,3-dichloropropene may increase the risk of asthma-related ED visits (low certainty evidence). Heatwaves and cold spells may increase the risk of asthma-related ED visits and HA and asthma mortality (low certainty evidence).</p

The conservation status of the world\u27s reptiles

Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world\u27s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human-induced habitat loss and harvesting, which are the predominant threats to reptiles. © 2012 Elsevier Ltd

Conservation status of the world’s reptiles

Effective conservation action requires knowledge of the distribution of threatened species and the threat processes affecting them. We present the first global assessment of extinction risk for a random representative sample of 1,500 reptile species. We find strong variation in extinction risk by taxonomic groups and geographic regions, with the most threatened reptiles associated with freshwater environments, tropical regions, and oceanic islands. Extinction risk is predominantly associated with habitat loss and over-exploitation. Our results emphasize the need for research attention to be focussed on tropical areas, which are seeing the highest extinction risk, and fossorial reptiles, for which there is a chronic lack of data

Motivações e significados do abandono de categoria: aprendizado a partir da investigação com ex-fumantes e ex-proprietários de automóveis

O presente trabalho investiga por que os indivíduos tomam a decisão de abandono de categoria, tendo em vista diferentes contextos de estímulo e questionamento ao consumo. Para isso, foram escolhidas as categorias de automóvel e cigarro, considerando-se o conteúdo do sistema da publicidade, que, no caso do automóvel, é predominantemente de reforço ao consumo e, para o cigarro, de proibição dos anúncios por parte da indústria e demarketing através das campanhas governamentais. A pesquisa utiliza-se de metodologia qualitativa de coleta e análise dos dados, obtidos a partir de entrevistas em profundidade com 29 consumidores (ex-fumantes e ex-proprietários de automóveis). O trabalho enriquece os estudos de anticonsumo ao diferenciar três tipos de abandono e evidenciar que este não é apenas movimento de distanciamento de significados negativos, com o objetivo de proteger a autoestima (Hogg et al., 2009), mas também passível de operar diferenciação afirmativa, positiva e de reforço da autoestima. O abandono contingencial acontece quando o indivíduo, apesar de compartilhar os significados com os consumidores da categoria, vê-se forçado a abandonar o consumo. O abandono posicional é motivado principalmente pela rejeição às associações simbólicas que o consumo proporciona. Por fim, o abandono ideológico apresenta uma perspectiva coletiva, onde o indivíduo acredita que a sociedade (e não apenas ele individualmente) deve abandonar aquele consumo

The impact of indoor pollution on asthma-related outcomes: a systematic review for the EAACI guidelines on environmental science for allergic diseases and asthma

Systematic review using GRADE of the impact of exposure to volatile organic compounds (VOCs), cleaning agents, mould/damp, pesticides on the risk of (i) new-onset asthma (incidence) and (ii) adverse asthma-related outcomes (impact). MEDLINE, EMBASE and Web of Science were searched for indoor pollutant exposure studies reporting on new-onset asthma and critical and important asthma-related outcomes. Ninety four studies were included: 11 for VOCs (7 for incidenceand 4 for impact), 25 for cleaning agents (7 for incidenceand 8 for impact), 48 for damp/mould (26 for incidence and 22 for impact) and 10 for pesticides (8 for incidence and 2 for impact). Exposure to damp/mould increases the risk of new-onset wheeze (moderate certainty evidence). Exposure to cleaning agents may be associated with a higher risk of new-onset asthma and with asthma severity (low level of certainty). Exposure to pesticides and VOCs may increase the risk of new-onset asthma (very low certainty evidence). The impact on asthma-related outcomes of all major indoor pollutants is uncertain. As the level of certainty is low or very low for most of the available evidence on the impact of indoor pollutants on asthma-related outcomes more rigorous research in the field is warranted.</p

Systemic Sclerosis Associated Interstitial Lung Disease: A Conceptual Framework for Subclinical, Clinical, and Progressive Disease

OBJECTIVES: Establish a framework by which experts define disease subsets in systemic sclerosis associated interstitial lung disease (SSc-ILD). METHODS: A conceptual framework for subclinical, clinical, and progressive ILD was provided to eighty-three experts, asking them to use the framework and classify actual SSc-ILD patients. Each patient profile was designed to be classified by at least 4 experts in terms of severity and risk of progression at baseline; progression was based on 1-year follow-up data. A consensus was reached if ≥ 75% of experts agreed. Experts provided information on which items were important in determining classification. RESULTS: Forty-four experts (53%) completed the survey. Consensus was achieved on the dimensions of severity (75%, 60 of 80 profiles), risk of progression (71%, 57 of 80 profiles) and progressive ILD (60%, 24 of 40 profiles). For profiles achieving consensus, most were classified as clinical ILD (92%), low risk (54%), and stable (71%). Severity and disease progression overlapped in terms of framework items that were most influential in classifying patients (forced vital capacity, extent of lung involvement on high resolution chest CT (HRCT)); risk of progression was influenced primarily by disease duration. CONCLUSIONS: Using our proposed conceptual framework, international experts were able to achieve a consensus on classifying SSc-ILD patients along the dimensions of disease severity, risk of progression, and progression over time. Experts rely on similar items when classifying disease severity and progression: a combination of spirometry and gas exchange and quantitative HRCT