The pseudogap: friend or foe of high Tc?

Although nineteen years have passed since the discovery of high temperature superconductivity, there is still no consensus on its physical origin. This is in large part because of a lack of understanding of the state of matter out of which the superconductivity arises. In optimally and underdoped materials, this state exhibits a pseudogap at temperatures large compared to the superconducting transition temperature. Although discovered only three years after the pioneering work of Bednorz and Muller, the physical origin of this pseudogap behavior and whether it constitutes a distinct phase of matter is still shrouded in mystery. In the summer of 2004, a band of physicists gathered for five weeks at the Aspen Center for Physics to discuss the pseudogap. In this perspective, we would like to summarize some of the results presented there and discuss its importance in the context of strongly correlated electron systems.Comment: expanded version, 20 pages, 11 figures, to be published, Advances in Physic

Time for first antibiotic dose is not predictive for the early clinical failure of moderate–severe community-acquired pneumonia

The time to first antibiotic dose (TFAD) has been mentioned as an important performance indicator in community-acquired pneumonia (CAP). However, the advice to minimise TFAD to 4 hours (4 h) is only based on database studies. We prospectively studied the effect of minimising the TFAD on the early clinical outcome of moderate–severe CAP. On admission, patients’ medical data and TFAD were recorded. Early clinical failure was expressed as the proportion of patients with clinical instability, admission to the intensive care unit (ICU) or mortality on day three. Of 166 patients included in the study, 27 patients (29.7%) with TFAD <4 h had early clinical failure compared to 23 patients (37.7%) with TFAD >4 h (odds ratio [OR] 0.69; 95% confidence interval [CI] 0.35–1.35). In multivariate analysis, the pneumonia severity index (OR 1.03; 95%CI 1.01–1.04), confusion (OR 2.63; 95%CI 1.14–6.06), Staphylococcus aureus infection (OR 7.26; 95%CI 1.33–39.69) and multilobar pneumonia (OR 2.40; 95%CI 1.11–5.22) but not TFAD were independently associated with early clinical failure. Clinical parameters on admission other than the TFAD predict early clinical outcome in moderate–severe CAP. In contrast to severe CAP necessitating treatment in the ICU directly, in the case of suspected moderate–severe CAP, there is time to establish a reliable diagnosis of CAP before antibiotics are administered. Therefore, the implementation of the TFAD as a performance indicator is not desirable

The Hubbard model within the equations of motion approach

The Hubbard model has a special role in Condensed Matter Theory as it is considered as the simplest Hamiltonian model one can write in order to describe anomalous physical properties of some class of real materials. Unfortunately, this model is not exactly solved except for some limits and therefore one should resort to analytical methods, like the Equations of Motion Approach, or to numerical techniques in order to attain a description of its relevant features in the whole range of physical parameters (interaction, filling and temperature). In this manuscript, the Composite Operator Method, which exploits the above mentioned analytical technique, is presented and systematically applied in order to get information about the behavior of all relevant properties of the model (local, thermodynamic, single- and two- particle ones) in comparison with many other analytical techniques, the above cited known limits and numerical simulations. Within this approach, the Hubbard model is shown to be also capable to describe some anomalous behaviors of the cuprate superconductors.Comment: 232 pages, more than 300 figures, more than 500 reference

Properties of Graphene: A Theoretical Perspective

In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

Genetic susceptibility to burnout in a Swedish twin cohort

Most previous studies of burnout have focused on work environmental stressors, while familial factors so far mainly have been overlooked. The aim of the study was to estimate the relative importance of genetic influences on burnout (measured with Pines Burnout Measure) in a sample of monozygotic (MZ) and dizygotic (DZ) Swedish twins. The study sample consisted of 20,286 individuals, born 1959–1986 from the Swedish twin registry who participated in the cross-sectional study of twin adults: genes and environment. Probandwise concordance rates (the risk for one twin to be affected given that his/her twin partner is affected by burnout) and within pair correlations were calculated for MZ and DZ same—and opposite sexed twin pairs. Heritability coefficients i.e. the proportion of the total variance attributable to genetic factors were calculated using standard biometrical model fitting procedures. The results showed that genetic factors explained 33% of the individual differences in burnout symptoms in women and men. Environmental factors explained a substantial part of the variation as well and are thus important to address in rehabilitation and prevention efforts to combat burnout

Pandemic influenza preparedness and health systems challenges in Asia: results from rapid analyses in 6 Asian countries

BACKGROUND: Since 2003, Asia-Pacific, particularly Southeast Asia, has received substantial attention because of the anticipation that it could be the epicentre of the next pandemic. There has been active investment but earlier review of pandemic preparedness plans in the region reveals that the translation of these strategic plans into operational plans is still lacking in some countries particularly those with low resources. The objective of this study is to understand the pandemic preparedness programmes, the health systems context, and challenges and constraints specific to the six Asian countries namely Cambodia, Indonesia, Lao PDR, Taiwan, Thailand, and Viet Nam in the prepandemic phase before the start of H1N1/2009. METHODS: The study relied on the Systemic Rapid Assessment (SYSRA) toolkit, which evaluates priority disease programmes by taking into account the programmes, the general health system, and the wider socio-cultural and political context. The components under review were: external context; stewardship and organisational arrangements; financing, resource generation and allocation; healthcare provision; and information systems. Qualitative and quantitative data were collected in the second half of 2008 based on a review of published data and interviews with key informants, exploring past and current patterns of health programme and pandemic response. RESULTS: The study shows that health systems in the six countries varied in regard to the epidemiological context, health care financing, and health service provision patterns. For pandemic preparation, all six countries have developed national governance on pandemic preparedness as well as national pandemic influenza preparedness plans and Avian and Human Influenza (AHI) response plans. However, the governance arrangements and the nature of the plans differed. In the five developing countries, the focus was on surveillance and rapid containment of poultry related transmission while preparation for later pandemic stages was limited. The interfaces and linkages between health system contexts and pandemic preparedness programmes in these countries were explored. CONCLUSION: Health system context influences how the six countries have been preparing themselves for a pandemic. At the same time, investment in pandemic preparation in the six Asian countries has contributed to improvement in health system surveillance, laboratory capacity, monitoring and evaluation and public communications. A number of suggestions for improvement were presented to strengthen the pandemic preparation and mitigation as well as to overcome some of the underlying health system constraints

Social Participation and Disaster Risk Reduction Behaviors in Tsunami Prone Areas

This paper examines the relationships between social participation and disaster risk reduction actions. A survey of 557 households in tsunami prone areas in Phang Nga, Thailand was conducted following the 2012 Indian Ocean earthquakes. We use a multivariate probit model to jointly estimate the likelihood of undertaking three responses to earthquake and tsunami hazards (namely, (1) following disaster-related news closely, (2) preparing emergency kits and/or having a family emergency plan, and (3) having an intention to migrate) and community participation.We find that those who experienced losses from the 2004 tsunami are more likely to participate in community activities and respond to earthquake hazards. Compared to men, women are more likely to prepare emergency kits and/or have an emergency plan and have a greater intention to migrate. Living in a community with a higher proportion of women with tertiary education increases the probability of engaging in community activities and carrying out disaster risk reduction measures. Individuals who participate in village-based activities are 5.2% more likely to undertake all three risk reduction actions compared to those not engaging in community activities. This implies that encouraging participation in community activities can have positive externalities in disaster mitigation

Loss of Cytoplasmic CDK1 Predicts Poor Survival in Human Lung Cancer and Confers Chemotherapeutic Resistance

The dismal lethality of lung cancer is due to late stage at diagnosis and inherent therapeutic resistance. The incorporation of targeted therapies has modestly improved clinical outcomes, but the identification of new targets could further improve clinical outcomes by guiding stratification of poor-risk early stage patients and individualizing therapeutic choices. We hypothesized that a sequential, combined microarray approach would be valuable to identify and validate new targets in lung cancer. We profiled gene expression signatures during lung epithelial cell immortalization and transformation, and showed that genes involved in mitosis were progressively enhanced in carcinogenesis. 28 genes were validated by immunoblotting and 4 genes were further evaluated in non-small cell lung cancer tissue microarrays. Although CDK1 was highly expressed in tumor tissues, its loss from the cytoplasm unexpectedly predicted poor survival and conferred resistance to chemotherapy in multiple cell lines, especially microtubule-directed agents. An analysis of expression of CDK1 and CDK1-associated genes in the NCI60 cell line database confirmed the broad association of these genes with chemotherapeutic responsiveness. These results have implications for personalizing lung cancer therapy and highlight the potential of combined approaches for biomarker discovery

Targeting the cell cycle for cancer therapy

Most if not all neoplasias show a directly or indirectly deregulated cell cycle. Targeting its regulatory molecules, the cyclin-dependent kinases, as a therapeutic mode to develop new anticancer drugs, is being currently explored in both academia and pharmaceutical companies. The development of new compounds is being focused on the many features of the cell cycle with promising preclinical data in most fields. Moreover, a few compounds have entered clinical trials with excellent results maintaining the high hopes. Thus, although too early to provide a cell cycle target based new commercial drug, there is no doubt that it will be an excellent source of new anticancer compounds