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The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes during the last interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from the Greenland NEEM ice core to reconstruct the environmental alterations in aerosol source regions accompanying these changes. Separating source and transport effects, we find strongly reduced terrestrial biogenic emissions during glacial times reflecting net loss of vegetated area in North America. Rapid climate changes during the glacial have little effect on terrestrial biogenic aerosol emissions. A strong increase in terrestrial dust emissions during the coldest intervals indicates higher aridity and dust storm activity in East Asian deserts. Glacial sea salt aerosol emissions in the North Atlantic region increase only moderately (50%), likely due to sea ice expansion. Lower aerosol concentrations in Eemian ice compared to the Holocene are mainly due to shortened atmospheric residence time, while emissions changed little., Past climate changes in Greenland ice were accompanied by large aerosol concentration changes. Here, the authors show that by correcting for transport effects, reliable source changes for biogenic aerosol from North America, sea salt aerosol from the North Atlantic, and dust from East Asian deserts can be derived.

For the past 14 years, the PAGES 2k Network has brought together a large, interdisciplinary community to better understand pre-industrial climate and give context to recent human-caused climate change. The past 2000 years of Earth\'s history provides a critical context for understanding climate variability and change. This is a period where climate changes occurred as a result of well characterized natural climate forcing, as well as unforced internal variability, and has now transitioned into a climate that is strongly forced by human factors. It is also a period where a range of paleoclimate proxy records, often with annual or better resolution, can be used to build up a comprehensive spatial understanding of our climate system. Recent step changes in computing capabilities now allow for ensembles of millennial-length climate-model simulations with which researchers can test and improve our knowledge of the climate system. All of these factors provide a rich scientific backdrop for the work of the PAGES 2k Network.

Assessing the economic reality and prospects of the Soviet Union was of major importance for U.S. policy-making throughout the Cold War. In the future, the U.S. is likely to be faced with adversaries with similarly opaque command (or mixed command and free market) economies; accurately assessing their size and health will remain an important U.S. intelligence task. This task is generally seen as requiring the development of complex quantitative methodologies which, despite their necessary reliance on poor quality and perhaps manipulated data, produce an output that can appear “objective” and precise. This can be counteracted in part by focusing on the likely biases in the input date, as caused, for example, by the ulterior motives of those providing it. Furthermore, intelligence must constantly be searching for, and making use of, new sources of insights even if they are more subjective and less precise in nature.

The past 2000 years (the “2k” interval) provides critical context for our understanding of recent anthropogenic forcing of the climate, as well as baseline information about Earth’s natural climate variability. It also provides opportunities to improve the interpretation of paleoclimate proxy observations, and to perform out-of-sample evaluation of the climate and earth system models that are used to generate projections of future climate change.

A sustained-release DepoFoam injection formulation of bupivacaine (EXPAREL, 15 mg/mL) is currently being investigated for postsurgical analgesia via peripheral nerve block (PNB). Single-dose toxicology studies of EXPAREL (9, 18, and 30 mg/kg), bupivacaine solution (Bsol, 9 mg/kg), and saline injected around the brachial plexus nerve bundle were performed in rabbits and dogs. The endpoints included clinical pathology, pharmacokinetics, and histopathology evaluation on Day 3 and Day 15 (2/sex/group/period). EXPAREL resulted in a nearly 4-fold lower Cmax versus Bsol at the same dose. EXPAREL was well tolerated at doses up to 30 mg/kg. The only EXPAREL-related effect seen was minimal to mild granulomatous inflammation of adipose tissue around nerve roots (8 of 24 rabbits and 7 of 24 dogs) in the brachial plexus sites. The results indicate that EXPAREL was well tolerated in these models and did not produce nerve damage after PNB in rabbits and dogs.