Processes for formation, cooling, and altering Earth's ocean crust are not yet completely understood due to challenges in access and sampling. Here, we use contiguous micro-imaging infrared spectroscopy to develop complete-core maps of mineral occurrence and investigate spatial patterns in the hydrothermal alteration of 1.2 km of oceanic crust recovered from Oman Drilling Project Holes GT1A, GT2A, and GT3A drilled in the Samail Ophiolite, Oman.
View Article and Find Full Text PDFA hidden carbon cycle exists inside Earth. Every year, megatons of carbon disappear into subduction zones, affecting atmospheric carbon dioxide and oxygen over Earth's history. Here we discuss the processes that move carbon towards subduction zones and transform it into fluids, magmas, volcanic gases and diamonds.
View Article and Find Full Text PDFAmorphous water ice comes in at least three distinct structural forms, all lacking long-range crystalline order. High-density amorphous ice (HDA) was first produced by compressing ice I to 11 kilobar at temperatures below 130 kelvin, and the process was described as thermodynamic melting, implying that HDA is a glassy state of water. This concept, and the ability to transform HDA reversibly into low-density amorphous ice, inspired the two-liquid water model, which relates the amorphous phases to two liquid waters in the deeply supercooled regime (below 228 kelvin) to explain many of the anomalies of water (such as density and heat capacity anomalies).
View Article and Find Full Text PDFCurrent estimates of the carbon flux between the surface and mantle are highly variable, and the total amount of carbon stored in closed hidden reservoirs is unknown. Understanding the forms in which carbon existed in the molten early Earth is a critical step towards quantifying the carbon budget of Earth's deep interior. Here we employ first-principles molecular dynamics to study the evolution of carbon species as a function of pressure in a pyrolite melt.
View Article and Find Full Text PDFWe report a fatal case of Lassa fever diagnosed in the United States in a Liberian traveler. We describe infection control protocols and public health response. One contact at high risk became symptomatic, but her samples tested negative for Lassa virus; no secondary cases occurred among health care, family, and community contacts.
View Article and Find Full Text PDFThe chemistry of aqueous fluids controls the transport and exchange-the cycles-of metals and volatile elements on Earth. Subduction zones, where oceanic plates sink into the Earth's interior, are the most important geodynamic setting for this fluid-mediated chemical exchange. Characterizing the ionic speciation and pH of fluids equilibrated with rocks at subduction zone conditions has long been a major challenge in Earth science.
View Article and Find Full Text PDFDuring the response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC addressed the disease on two fronts: in the epidemic epicenter of West Africa and at home in the United States. Different needs drove the demand for information in these two regions. The severity of the epidemic was reflected not only in lives lost but also in the amount of fear, misinformation, and stigma that it generated worldwide.
View Article and Find Full Text PDFSince the first mammal was cloned, the idea of using this technique to help endangered species has aroused considerable interest. However, several issues limit this possibility, including the relatively low success rate at every stage of the cloning process, and the dearth of usable tissues from these rare animals. iPS cells have been produced from cells from a number of rare mammalian species and this is the method of choice for strategies to improve cloning efficiency and create new gametes by directed differentiation.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2015
Carbon fluxes in subduction zones can be better constrained by including new estimates of carbon concentration in subducting mantle peridotites, consideration of carbonate solubility in aqueous fluid along subduction geotherms, and diapirism of carbon-bearing metasediments. Whereas previous studies concluded that about half the subducting carbon is returned to the convecting mantle, we find that relatively little carbon may be recycled. If so, input from subduction zones into the overlying plate is larger than output from arc volcanoes plus diffuse venting, and substantial quantities of carbon are stored in the mantle lithosphere and crust.
View Article and Find Full Text PDFKnowledge of the occurrence and mobility of carbonate-rich melts in the Earth's mantle is important for understanding the deep carbon cycle and related geochemical and geophysical processes. However, our understanding of the mobility of carbonate-rich melts remains poor. Here we report viscosities of carbonate melts up to 6.
View Article and Find Full Text PDFIn summer 2012, an outbreak of hantavirus infections occurred among overnight visitors to Yosemite National Park in California, USA. An investigation encompassing clinical, epidemiologic, laboratory, and environmental factors identified 10 cases among residents of 3 states. Eight case-patients experienced hantavirus pulmonary syndrome, of whom 5 required intensive care with ventilatory support and 3 died.
View Article and Find Full Text PDFWe investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.
View Article and Find Full Text PDFThe laboratory mouse is a key animal model for studies of adipose biology, metabolism and disease, yet the developmental changes that occur in tissues and cells that become the adipose layer in mouse skin have received little attention. Moreover, the terminology around this adipose body is often confusing, as frequently no distinction is made between adipose tissue within the skin, and so called subcutaneous fat. Here adipocyte development in mouse dorsal skin was investigated from before birth to the end of the first hair follicle growth cycle.
View Article and Find Full Text PDFMarburg hemorrhagic fever was detected among 4 miners in Ibanda District, Uganda, from June through September, 2007. Infection was likely acquired through exposure to bats or bat secretions in a mine in Kamwenge District, Uganda, and possibly human-to-human transmission between some patients. We describe the epidemiologic investigation and the health education response.
View Article and Find Full Text PDFWe report a case of Lassa fever in a US traveler who visited rural Liberia, became ill while in country, sought medical care upon return to the United States, and subsequently had his illness laboratory confirmed. The patient recovered with supportive therapy. No secondary cases occurred.
View Article and Find Full Text PDFThe first approximately 600 million years of Earth history (the 'Hadean' eon) remain poorly understood, largely because there is no rock record dating from that era. Detrital Hadean igneous zircons from the Jack Hills, Western Australia, however, can potentially provide insights into the conditions extant on our planet at that time. Results of geochemical investigations using these ancient grains have been interpreted to suggest the presence of a hydrosphere and continental crust before 4 Gyr.
View Article and Find Full Text PDFThis study investigated the patterns of attributions for success made by intercollegiate athletes in three categories: more versus less successful teams, men versus women athletes, and individual versus group sport participants. 74 men and 83 women on 17 varsity teams across a number of sports took the Sports Attribution Style Scale, measuring internal, stable, controllable, intentional, and global attributions. It was hypothesized that (a) the athletes on more successful teams would have higher internal, stable, controllable, and intentional attributions, (b) that athletes in individual sports would have lower internal, stable, and controllable attributions, and (c) that women would score higher on all five attributions.
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