364 research outputs found
Covariability of dissolved oxygen with physical processes in the summertime Chesapeake Bay
Long, rapidly sampled time series measurements of dissolved oxygen, temperature, salinity, currents, winds, tides, and insolation were collected during the summer of 1987 across the mesohaline Chesapeake Bay. Analyses of the data show that short term variability of dissolved oxygen was both large and spatially heterogeneous. Time scales of variability ranged from the longest period fluctuations resolved (several days) to the sampling interval (several minutes). The largest variability was associated with large amplitude, wind and tide forced lateral internal oscillations of the pycnocline in the mainstem of the Bay. These resulted in advection of saline, hypoxic water from below the pycnocline onto the flanks of the Bay and into the lower reaches of the Choptank River, an adjoining tributary estuary. Advective variability at higher frequencies was likely due to internal waves, internal mixing, and/or spatial patchiness. Dissolved oxygen also responded to the daily cycle of insolation, but lagged insolation by at least 90° (6 h). Advective variability of dissolved oxygen is implicated as an important characteristic of the majority of summertime benthic environments in the mesohaline Chesapeake Bay and lower reaches of adjoining tributaries
Preface
Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in
Deep Sea Research Part II: Topical Studies in Oceanography 103 (2014): 1-5, doi:10.1016/j.dsr2.2014.02.007.The Gulf of Maine (GOM) is a continental shelf sea in the northwest Atlantic, USA that supports highly-productive shellfisheries that are frequently contaminated by toxigenic Alexandrium fundyense blooms and outbreaks of paralytic shellfish poisoning (PSP), resulting in significant economic and social impacts. Additionally, an emerging threat to these resources is from blooms of toxic Pseudo-nitzschia species that produce domoic acid, the toxin responsible for amnesic shellfish poisoning (ASP). Nearshore shellfish toxins are monitored by state agencies, whereas most offshore stocks have had little or no routine monitoring. As a result, large areas of federal waters have been indefinitely closed or their shellfish beds underexploited because of the potential risk these toxins pose and the lack of scientific understanding and management tools. Patterns and dynamics of Alexandrium blooms and the resulting shellfish toxicity in nearshore waters were examined in a number of research projects, the largest being the Ecology and Oceanography of Harmful Algal Blooms (ECOHAB)-Gulf of Maine (GOM), a five-year regional program emphasizing field surveys, laboratory studies and numerical modeling. At the completion of the ECOHAB-GOM program (documented in Anderson et al., 2005), great progress was made in understanding A. fundyense blooms and resulting shellfish toxicity in nearshore waters, but there were major unknowns that still required investigation. For example, little was known about A. fundyense bloom dynamics in the waters south and east of Cape Cod, Massachusetts, and in particular, about the link between blooms in surface waters and toxicity in deep offshore shellfish. Large areas of offshore shellfish beds were off limits to harvest, including a 40,000 km2 region closed during the 2005 bloom and a much larger zone (~80,000 km2) including portions of Georges Bank was closed in 1990 after high levels of PSP toxicity were detected. In recent years, pressures were mounting from industry to open those offshore areas and to develop management strategies so that surfclam (Spisula solidissima), ocean quahog (Arctica islandica), and roe-on sea scallop (Placopecten magellanicus) fisheries could be opened. In response to these unknowns and societal needs, a new multi-investigator program, GOMTOX (Gulf of Maine Toxicity), was formulated and ultimately funded through the NOAA ECOHAB program. GOMTOX was a regional observation and modeling program that investigated the patterns and mechanisms underlying A. fundyense and Pseudo-nitzschia blooms and the resulting toxicity in shellfish in the southern GOM and its adjacent New England shelf waters, with special emphasis on the delivery pathways, mechanisms, and dynamics of offshore shellfish toxicity. The GOMTOX team of investigators included 16 principal investigators from eight institutions and, continuing in the ECOHAB-GOM tradition, strong participation from federal and state resource managers as well as representatives of the shellfish industry.
This team worked together for over five years, running numerous large-scale survey cruises of Alexandrium cells and cysts, and also supporting industry cruises to collect shellfish from offshore sites including Georges Bank. Other efforts included participation in National Marine Fisheries Service surveys for shellfish (sea scallops, surfclams, and ocean quahogs), numerical modeling studies, deployment of sediment traps, and laboratory and ship-based experiments to investigate grazing and other processes that might regulate blooms and deliver toxins to shellfish in deeper waters. A smaller-scale but concurrent effort collected samples to characterize Pseudo-nitzschia species and their potential toxicity in the region.We gratefully acknowledge the support of NOAA through the ECOHAB program. Partial support for some of the studies contained herein was provided by NSF and NIEHS through the Woods Hole Center for Oceans and Human Health. Funding for J.L. Martin’s contributions from the Bay of Fundy was provided by Fisheries and Oceans Canada and NERACOOS, which is a part of the U.S. Integrated Ocean Observing System, funded in part by National Oceanic and Atmospheric Administration (NOAA)
Lessons Learned From Efforts To Restore Oyster Populations In Maryland And Virginia, 1990 To 2007
A century-long decline of the fishery for the Eastern oyster Crassostrea virginica (Gmelin, 1791) in Maryland and Virginia stimulated numerous efforts by federal, state, and nongovernmental agencies to restore oyster populations, with limited success. To learn from recent efforts, we analyzed records of restoration and monitoring activities undertaken between 1990 and 2007 by 12 such agencies. Of the 1,037 oyster bars (reefs, beds, or grounds) for which we obtained data, 43% experienced both restoration and monitoring, with the remaining experiencing either restoration or monitoring only. Restoration activities involved adding substrate (shell), transplanting hatchery or wild seed (juvenile oysters), bar cleaning, and bagless dredging. Of these, substrate addition and transplanting seed were common actions, with bar cleaning and bagless dredging relatively uncommon. Limited monitoring efforts, a lack of replicated postrestoration sampling, and the effects of harvest on some restored bars hinders evaluations of the effectiveness of restoration activities. Future restoration activities should have clearly articulated objectives and be coordinated among agencies and across bars, which should also be off limits to fishing. To evaluate restoration efforts, experimental designs should include replication, quantitative sampling, and robust sample sizes, supplemented by pre- and postrestoration monitoring
The importance of human dimensions research in managing harmful algal blooms
Author Posting. © Ecological Society of America, 2010. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Frontiers in Ecology and the Environment 8 (2010): 75–83, doi:10.1890/070181.Harmful algal blooms (HABs) are natural freshwater and marine hazards that impose substantial adverse impacts on the human use of coastal and marine resources. The socioeconomic and health impacts of HABs can be considerable, thereby making a case for “human dimensions” research to support HAB response. Human dimensions research is multidisciplinary, integrating social science, humanities, and other fields with natural science to enhance resource management by addressing human causes, consequences, and responses to coastal environmental problems. Case studies reported here illustrate the importance of human dimensions research. Incorporating such research into the scientific agenda – as well as into management decisions of public agencies concerned with natural resource management, environmental protection, and public health and welfare – requires the development of both strategic guidance and institutional capacity. The recent development of a multi-agency research strategy for HAB response and a strategic plan for human dimensions research represent two important steps in this direction.This paper was developed with partial support from
NOAA’s National Centers for Coastal and Ocean Science
Rapid diagnosis of experimental meningitis by bacterial heat production in cerebrospinal fluid
BACKGROUND: Calorimetry is a nonspecific technique which allows direct measurement of heat generated by biological processes in the living cell. We evaluated the potential of calorimetry for rapid detection of bacterial growth in cerebrospinal fluid (CSF) in a rat model of bacterial meningitis. METHODS: Infant rats were infected on postnatal day 11 by direct intracisternal injection with either Streptococcus pneumoniae, Neisseria meningitidis or Listeria monocytogenes. Control animals were injected with sterile saline or heat-inactivated S. pneumoniae. CSF was obtained at 18 hours after infection for quantitative cultures and heat flow measurement. For calorimetry, 10 microl and 1 microl CSF were inoculated in calorimetry ampoules containing 3 ml trypticase soy broth (TSB). RESULTS: The mean bacterial titer (+/- SD) in CSF was 1.5 +/- 0.6 x 108 for S. pneumoniae, 1.3 +/- 0.3 x 106 for N. meningitidis and 3.5 +/- 2.2 x 104 for L. monocytogenes. Calorimetric detection time was defined as the time until heat flow signal exceeded 10 microW. Heat signal was detected in 10-microl CSF samples from all infected animals with a mean (+/- SD) detection time of 1.5 +/- 0.2 hours for S. pneumoniae, 3.9 +/- 0.7 hours for N. meningitidis and 9.1 +/- 0.5 hours for L. monocytogenes. CSF samples from non-infected animals generated no increasing heat flow (<10 microW). The total heat was the highest in S. pneumoniae ranging from 6.7 to 7.5 Joules, followed by L. monocytogenes (5.6 to 6.1 Joules) and N. meningitidis (3.5 to 4.4 Joules). The lowest detectable bacterial titer by calorimetry was 2 cfu for S. pneumoniae, 4 cfu for N. meningitidis and 7 cfu for L. monocytogenes. CONCLUSION: By means of calorimetry, detection times of <4 hours for S. pneumoniae and N. meningitidis and <10 hours for Listeria monocytogenes using as little as 10 microl CSF were achieved. Calorimetry is a new diagnostic method allowing rapid and accurate diagnosis of bacterial meningitis from a small volume of CSF
EBMT prospective observational study on allogeneic hematopoietic stem cell transplantation in T-prolymphocytic leukemia (T-PLL)
Preliminary data suggest that allogeneic stem cell transplantation (allo-SCT) may be effective in T-prolymphocytic leukemia (T-PLL). The purpose of the present observational study was to assess the outcome of allo-SCT in patients aged 65 years or younger with a centrally confirmed diagnosis of T-PLL. Patients were consecutively registered with the EBMT at the time of transplantation and followed by routine EBMT monitoring but with an extended dataset. Between 2007 and 2012, 37 evaluable patients (median age 56 years) were accrued. Pre-treatment contained alemtuzumab in 95% of patients. Sixty-two percent were in complete remission (CR) at the time of allo-SCT. Conditioning contained total body irradiation with 6 Gy or more (TBI6) in 30% of patients. With a median follow-up of 50 months, the 4-year non-relapse mortality, relapse incidence, progression-free (PFS) and overall survival were 32, 38, 30 and 42%, respectively. By univariate analysis, TBI6 in the conditioning was the only significant predictor for a low relapse risk, and an interval between diagnosis and allo-SCT of more than 12 months was associated with a lower NRM. This study confirms for the first time prospectively that allo-SCT can provide long-term disease control in a sizable albeit limited proportion of patients with T-PLL.Peer reviewe
Analysis of large deletions in BRCA1, BRCA2 and PALB2 genes in Finnish breast and ovarian cancer families
DNA Topology Influences Molecular Machine Lifetime in Human Serum
DNA nanotechnology holds the potential for enabling new tools for biomedical engineering, including diagnosis, prognosis, and therapeutics. However, applications for DNA devices are thought to be limited by rapid enzymatic degradation in serum and blood. Here, we demonstrate that a key aspect of DNA nanotechnology—programmable molecular shape—plays a substantial role in device lifetimes. These results establish the ability to operate synthetic DNA devices in the presence of endogenous enzymes and challenge the textbook view of near instantaneous degradation
A novel de novo BRCA1 mutation in a Chinese woman with early onset breast cancer
Germline mutations in the two breast cancer susceptibility genes, BRCA1 and BRCA2 account for a significant portion of hereditary breast/ovarian cancer. De novo mutations such as multiple exon deletion are rarely occurred in BRCA1 and BRCA2. During our mutation screening for BRCA1/2 genes to Chinese women with risk factors for hereditary breast/ovarian cancer, we identified a novel germline mutation, consisting of a deletion from exons 1 to 12 in BRCA1 gene, in a patient diagnosed with early onset triple negative breast cancer with no family history of cancer. None of her parents carried the mutation and molecular analysis showed that this novel de novo germline mutation resulted in down-regulation of BRCA1 gene expression
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