Potential new production estimates in four eastern boundary upwelling ecosystems

International audienc

A Novel Photosynthetic Strategy for Adaptation to Low-Iron Aquatic Environments

Iron (Fe) availability is a major limiting factor for primary production in aquatic environments. Cyanobacteria respond to Fe deficiency by derepressing the isiAB operon, which encodes the antenna protein IsiA and flavodoxin. At nanomolar Fe concentrations, a PSI-IsiA supercomplex forms, comprising a PSI trimer encircled by two complete IsiA rings. This PSI-IsiA supercomplex is the largest photosynthetic membrane protein complex yet isolated. This study presents a detailed characterization of this complex using transmission electron microscopy and ultrafast fluorescence spectroscopy. Excitation trapping and electron transfer are highly efficient, allowing cyanobacteria to avoid oxidative stress. This mechanism may be a major factor used by cyanobacteria to successfully adapt to modern low-Fe environments.

Temporal Variations in the Photosynthetic Biosphere

In this report, we describe results from the first three years of global Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) ocean chlorophyll and land plant measurements. This time period covered the end of one of the largest El Nino events in the past century and a strong La Nina. During this transition, terrestrial plant photosynthesis exhibited only a small change, whereas a significant increase in oceanic photosynthesis was observed. Latitudinal distributions of ocean production indicated that this increase in photosynthesis during the La Nina was distributed in the equatorial belt as well as in high production areas. The analysis also illustrated the large 'missing bloom' in ocean phytoplankton in the southern ocean. While land photosynthesis remained fairly steady during the third year of SeaWiFS measurements, ocean phytoplankton production continued to increase, albeit at a lower rate than from 1997 to 1999. Our results represent the first quantification of interannual variability in global scale ocean productivity. Significant Findings: An increase in ocean production during the first three years of the SeaWiFS mission; a strong hemispheric difference in the latitudinal distribution of ocean photosynthesis

Biospheric Primary Production During an ENSO Transition

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) provides global monthly measurements of both oceanic phytoplankton chlorophyll biomass and light harvesting by land plants. These measurements allowed the comparison of simultaneous ocean and land net primary production (NPP) responses to a major El Niño to La Niña transition. Between September 1997 and August 2000, biospheric NPP varied by 6 petagrams of carbon per year (from 111 to 117 petagrams of carbon per year). Increases in ocean NPP were pronounced in tropical regions where El Niño–Southern Oscillation (ENSO) impacts on upwelling and nutrient availability were greatest. Globally, land NPP did not exhibit a clear ENSO response, although regional changes were substantial

Biospheric Primary Production During an ENSO Transition

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) provides global monthly measurements of both oceanic phytoplankton chlorophyll biomass and light harvesting by land plants. These measurements allowed the comparison of simultaneous ocean and land net primary production (NPP) responses to a major El Niño to La Niña transition. Between September 1997 and August 2000, biospheric NPP varied by 6 petagrams of carbon per year (from 111 to 117 petagrams of carbon per year). Increases in ocean NPP were pronounced in tropical regions where El Niño–Southern Oscillation (ENSO) impacts on upwelling and nutrient availability were greatest. Globally, land NPP did not exhibit a clear ENSO response, although regional changes were substantial

DHHS publication ; no. (NIOSH)

The Healthcare and Social Assistance Program\ue2\u20ac\u2122s mission is to eliminate occu- pational diseases, injuries, and fatalities in industries providing human and vet- erinary healthcare and social assistance services across a broad range of set- tings such as hospitals, clinics, nursing and private homes, and child day care. This snapshot shows recent accom- plishments and upcoming work.What are our priorities? The National Institute for Occupational Safety and Health (NIOSH) Healthcare and Social Assistance Program works with partners in industry, labor, trade associations, professional organizations, and academia. The program focuses on these areas: 1. Reducing non-fatal work-related injuries in priority healthcare and social assistance areas, such as injuries caused by patient lifting; violence; slips, trips, and falls; and use of sharps devices. 2. Reducing work-related diseases and associated risk factors in healthcare and social assistance, including infectious, respiratory, dermal, and other diseases and health outcomes. What do we do? 1. Conduct surveillance for injuries, diseases, and risk factors in healthcare and social assistance. Provide findings to the research community, employers, workers, and other stakeholders to guide research and prevention efforts. 2. Develop and demonstrate effective methods of prevention in healthcare and social assistance. Make recommendations that can be used by professional healthcare organizations, employers, workers, and government agencies. 3. Disseminate useful prevention strategies for all healthcare and social assistance workers. Reduce disparities through outreach to higher-risk, underserved and vulnerable healthcare and social assistance worker populations. 4. Address knowledge gaps that are barriers to developing effective prevention strategies in healthcare and social assistance. Examples include determining risk factors for disease transmission and injury mechanisms. What have we accomplished? 1. Inspired a National Public Radio (NPR) investigative report on safe patient handling that reached an audience of 1.8 million "All Things Considered" listeners. As a result, the Occupational Safety and Health Administration (OSHA) launched a new initiative to investigate safe patient handling among nurses in hospitals. 2. Published a training course "NIOSH Training for Nurses on Shift Work and Long Hours," available for desktop and mobile devices on the NIOSH website. As of February 29, 2016, more than 1000 nurses and nurse managers completed the course, with most receiving continuing education credits. 3. Published a study supporting the need for annual fit testing for users of N95 filtering face-piece respirators. 4. Published training course "Workplace Violence Prevention for Nurses," available for desktop and mobile devices on the NIOSH website. As of January 31, 2016, 15,442 nurses had completed the modules, most receiving continuing education credits. 5. Led an interdisciplinary group that published a report in a peer-reviewed journal identifying knowledge gaps and other challenges related to cleaning and disinfecting in healthcare. 6. Developed OSHA-cobranded "Hospital Respiratory Protection Toolkit" to help hospital respirator program administrators. The toolkit emphasizes preventing the spread of infectious diseases to healthcare workers. What's next? 1. Publish findings from a survey of private dental practices on extent of use of bloodborne pathogens exposure control plans, barriers to use, and strategies to overcome barriers. 2. Publish findings from a survey of healthcare workers showing to what extent engineering controls are used for minimizing exposure to surgical smoke and anesthetic gases in hospitals and ambulatory care settings. 3. Add a surveillance module to NIOSH's Occupational Health Safety Network (OHSN). It will allow participating hospitals to track sharps injuries and benchmark their performance. 4. Release an update to the NIOSH Hazardous Drug list.NIOSHTIC No 2004812