Leverage demand-side policies for energy security.

Conventional supply-side approaches overlook potential benefits.

Economy-wide evaluation of CO2 and air quality impacts of electrification in the United States.

Adopting electric end-use technologies instead of fossil-fueled alternatives, known as electrification, is an important economy-wide decarbonization strategy that also reduces criteria pollutant emissions and improves air quality. In this study, we evaluate CO2 and air quality co-benefits of electrification scenarios by linking a detailed energy systems model and a full-form photochemical air quality model in the United States. We find that electrification can substantially lower CO2 and improve air quality and that decarbonization policy can amplify these trends, which yield immediate and localized benefits. In particular, transport electrification can improve ozone and fine particulate matter (PM2.5), though the magnitude of changes varies regionally. However, growing activity from non-energy-related PM2.5 sources-such as fugitive dust and agricultural emissions-can offset electrification benefits, suggesting that additional measures beyond CO2 policy and electrification are needed to meet air quality goals. We illustrate how commonly used marginal emissions approaches systematically underestimate reductions from electrification.

Probabilistic cost estimates for climate change mitigation.

For more than a decade, the target of keeping global warming below 2 °C has been a key focus of the international climate debate. In response, the scientific community has published a number of scenario studies that estimate the costs of achieving such a target. Producing these estimates remains a challenge, particularly because of relatively well known, but poorly quantified, uncertainties, and owing to limited integration of scientific knowledge across disciplines. The integrated assessment community, on the one hand, has extensively assessed the influence of technological and socio-economic uncertainties on low-carbon scenarios and associated costs. The climate modelling community, on the other hand, has spent years improving its understanding of the geophysical response of the Earth system to emissions of greenhouse gases. This geophysical response remains a key uncertainty in the cost of mitigation scenarios but has been integrated with assessments of other uncertainties in only a rudimentary manner, that is, for equilibrium conditions. Here we bridge this gap between the two research communities by generating distributions of the costs associated with limiting transient global temperature increase to below specific values, taking into account uncertainties in four factors: geophysical, technological, social and political. We find that political choices that delay mitigation have the largest effect on the cost-risk distribution, followed by geophysical uncertainties, social factors influencing future energy demand and, lastly, technological uncertainties surrounding the availability of greenhouse gas mitigation options. Our information on temperature risk and mitigation costs provides crucial information for policy-making, because it clarifies the relative importance of mitigation costs, energy demand and the timing of global action in reducing the risk of exceeding a global temperature increase of 2 °C, or other limits such as 3 °C or 1.5 °C, across a wide range of scenarios.

Detection, treatment, and prevention of Clostridium difficile infection.

Clostridium difficile is a gram-positive anaerobic bacillus responsible for approximately 1 of 5 cases of antibiotic-associated diarrhea. C difficile infection (CDI) is defined by at least 3 unformed stools in a 24-hour period and stool, endoscopic, or histopathologic test results that indicate the presence of this bacteria. The history of CDI research can be divided into early (before 2000) and modern eras (after 2000). C difficile was first described in 1935, and the characteristics and causes of CDI as well as therapies were identified during the early era of research. During the modern era, CDI has become a more common, aggressive nosocomial infection. Our understanding of the epidemiology, diagnosis, treatment, and prevention of CDI has increased at a rapid pace. We review features of CDI diagnosis, treatment, and prevention.

Update of the past year: a review from IDSA 2011.

The Infectious Diseases Society of America Annual Meeting serves as a time of expert review of the year's most important innovations. Important new information on HIV infection incidence was discussed. The remarkable efficacy of "treatment as prevention" in the HIV Prevention Trials Network (HPTN) 052 study and the proper place of oral preexposure prophylaxis were among the important prevention topics. Key engagement-in-care research indicates that only 19% of HIV-infected persons in the United States have a plasma HIV RNA level below the limits of assay detection. Among antiretroviral topics, the role of the newly approved nonnucleoside reverse transcriptase inhibitor (NNRTI) rilpivirine was discussed. Primary care topics for the HIV-infected population included treatment of triglyceride level elevations and bone health. The newly published data on the proper timing of antiretroviral therapy initiation after starting tuberculosis treatment were highlighted. Finally, exciting advances in the treatment of hepatitis C virus (HCV) infection necessitate that practitioners understand the complexities of treating HIV/HCV coinfections.

Severe sinus bradycardia after initiation of bupropion therapy: a probable drug-drug interaction with metoprolol.

Bupropion is an increasingly prescribed agent to aid in smoking cessation. However it has important drug-drug interactions related to the cytochrome P450 system. One of these is its inhibition of the metabolism of the commonly used beta-blocker, metoprolol. The authors describe a case of severe bradycardia related to the addition of bupropion to the medical regimen of a patient on metoprolol.