The worldwide marine radiocarbon reservoir effect: definitions, mechanisms, and prospects

When a carbon reservoir has a lower radiocarbon content than the atmosphere, this is referred to as a reservoir effect. This is expressed as an offset between the radiocarbon ages of samples from the two reservoirs at a single point in time. The marine reservoir effect (MRE) has been a major concern in the radiocarbon community, as it introduces an additional source of error that is often difficult to accurately quantify. For this reason, researchers are often reluctant to date marine material where they have another option. The influence of this phenomenon makes the study of the MRE important for a broad range of applications. The advent of Accelerator Mass Spectrometry (AMS) has reduced sample size requirements and increased measurement precision, in turn increasing the number of studies seeking to measure marine samples. These studies rely on overcoming the influence of the MRE on marine radiocarbon dates through the worldwide quantification of the local parameter ΔR, that is, the local variation from the global average MRE. Furthermore, the strong dependence on ocean dynamics makes the MRE a useful indicator for changes in oceanic circulation, carbon exchange between reservoirs, and the fate of atmospheric CO2, all of which impact Earth's climate. This article explores data from the Marine Reservoir Database and reviews the place of natural radiocarbon in oceanic records, focusing on key questions (e.g., changes in ocean dynamics) that have been answered by MRE studies and on their application to different subjects

Pathogen Sensing Pathways in Human Embryonic Stem Cell Derived-Endothelial Cells: Role of NOD1 Receptors.

Human embryonic stem cell-derived endothelial cells (hESC-EC), as well as other stem cell derived endothelial cells, have a range of applications in cardiovascular research and disease treatment. Endothelial cells sense Gram-negative bacteria via the pattern recognition receptors (PRR) Toll-like receptor (TLR)-4 and nucleotide-binding oligomerisation domain-containing protein (NOD)-1. These pathways are important in terms of sensing infection, but TLR4 is also associated with vascular inflammation and atherosclerosis. Here, we have compared TLR4 and NOD1 responses in hESC-EC with those of endothelial cells derived from other stem cells and with human umbilical vein endothelial cells (HUVEC). HUVEC, endothelial cells derived from blood progenitors (blood outgrowth endothelial cells; BOEC), and from induced pluripotent stem cells all displayed both a TLR4 and NOD1 response. However, hESC-EC had no TLR4 function, but did have functional NOD1 receptors. In vivo conditioning in nude rats did not confer TLR4 expression in hESC-EC. Despite having no TLR4 function, hESC-EC sensed Gram-negative bacteria, a response that was found to be mediated by NOD1 and the associated RIP2 signalling pathways. Thus, hESC-EC are TLR4 deficient but respond to bacteria via NOD1. This data suggests that hESC-EC may be protected from unwanted TLR4-mediated vascular inflammation, thus offering a potential therapeutic advantage

Bio-cultural refugia—Safeguarding diversity of practices for food security and biodiversity

Food security for a growing world population is high on the list of grand sustainability challenges, as is reducing the pace of biodiversity loss in landscapes of food production. Here we shed new insights on areas that harbor place specific social memories related to food security and stewardship of biodiversity. We call them bio-cultural refugia. Our goals are to illuminate how bio-cultural refugia store, revive and transmit memory of agricultural biodiversity and ecosystem services, and how such social memories are carried forward between people and across cohorts. We discuss the functions of such refugia for addressing the twin goals of food security and biodiversity conservation in landscapes of food production. The methodological approach is first of its kind in combining the discourses on food security, social memory and biodiversity management. We find that the rich biodiversity of many regionally distinct cultural landscapes has been maintained through a mosaic of management practices that have co-evolved in relation to local environmental fluctuations, and that such practices are carried forward by both biophysical and social features in bio-cultural refugia including; genotypes, artifacts, written accounts, as well as embodied rituals, art, oral traditions and self-organized systems of rules. Combined these structure a diverse portfolio of practices that result in genetic reservoirs-source areas-for the wide array of species, which in interplay produce vital ecosystem services, needed for future food security related to environmental uncertainties, volatile financial markets and large scale conflicts. In Europe, processes related to the large-scale industrialization of agriculture threaten such bio-cultural refugia. The paper highlights that the dual goals to reduce pressures from modern agriculture on biodiversity, while maintaining food security, entails more extensive collaboration with farmers oriented toward ecologically sound practices. (C) 2013 Elsevier Ltd. All rights reserved

FROM THE LIBRARY DIRECTOR

or several years UAMS librarians, along with other librarians throughout the country, have been monitoring the F development of the PubMed database (which includes MEDLINE) provided for free by the National Library of Medicine (NIH). During the past year, UAMS reference librarians did an in-depth comparison of PubMed and the Ovid MEDLINE product to which the Library currently subscribes. After studying the features of both systems that seem most important to our users, we considered PubMed to be the better option for UAMS for several major reasons. Therefore, we are planning to cancel the Ovid MEDLINE subscription effective July 1, 2006, giving Ovid MEDLINE users nearly a year for the transition to PubMed. Some of the reasons we selected PubMed over Ovid MEDLINE are as follows: Open Accessibility and Life-Long Learning PubMed is a free resource from the National Library of Medicine that will continue to be available via the Internet to faculty, students, and staff even after they leave UAMS. In the spirit of life-long learning, students and faculty will be acquiring the skills needed to search a database that will be available wherever they practice their health sciences profession. Ovid Costs and Restriction

BUDGET UPDATE

n a previous article of this newsletter, I reported on the budget situation in the UAMS Library. Two-thirds of our I collections budget is spent on journals, databases and software from two large European conglomerates. Unfortunately, during the past few years these conglomerates have increased the prices for their products more than the usual 10-15 % increases we normally pay for journal subscriptions. I am happy to report that the UAMS Administration has approved a $50,000 increase in the Library’s journal budget for the coming year, which will help us to avoid major cuts in our journal subscriptions for 2004. We will continue to look for good ways to deal with our budget situation, such as looking for alternative sources of funding and working with consortia to get reduced prices for some journal packages. However, these efforts just address the symptoms and not the problem itself, which is the control of scholarly publishing by large for-profit conglomerates which have monopolies on the biomedical publishing market. Some initiatives are attempting to change the process of scholarly publishing itself, such as BioMed Central (BMC). BMC (www.biomedcentral.com) is an independent publishing house which provides online access to peer-reviewed biomedical articles. It publishes journals in a wide range of biomedical subject categories, the journals have editorial boards and peer-review processes similar to those for traditional print journals, the articles are indexed in MEDLINE, and the free BMC journals are availabl