55 research outputs found
Separation and Characterization of Respirable Amphibole Fibers from Libby, Montana
The vermiculite mine in Libby, Montana, was in operation for over 70 yr and was contaminated with asbestos-like amphibole fibers. The mining, processing, and shipping of this vermiculite led to significant fiber inhalation exposure throughout the community, and residents of Libby have developed numerous pulmonary diseases such as lung cancer and mesothelioma. The present study describes the separation of Libby 6-mix into respirable and nonrespirable size fractions by means of aqueous elutriation. The elutriator, designed to separate fibers with aerodynamic diameters smaller than 2.5 μm (respirable) from larger fibers, used an upward flow rate of 3.4 × 10−4 cm s−1. The resultant respirable fraction constituted only 13% of the raw Libby 6-mix mass, and less than 2% of the fibers in the elutriated fraction had aerodynamic diameters exceeding 2.5 μm. Surface area of the elutriated fibers was 5.3 m−2 g−1, compared to 0.53 m−2 g−1 for the raw fibers. There were no detectable differences in chemical composition between the larger and smaller fibers. Such harvesting of respirable fractions will allow toxicological studies to be conducted within a controlled laboratory setting, utilizing fiber sizes that may more accurately simulate historical exposure of Libby residents’ lungs. Importantly, this work describes a method that allows the use of material enriched in more uniform respirable material than raw Libby 6-mix, making comparisons with other known fiber preparations more valid on a mass basis
Fate of Libby Amphibole Fibers When Burning Contaminated Firewood
In Libby, Montana, over 70 years of mining amphibole-contaminated vermiculite has led to amphibole contamination in areas surrounding the abandoned mine and in other areas throughout the town. In addition to contaminated soils, tree bark has also been found to be contaminated with amphibole fibers throughout the Libby area. As residential woodstoves are the main source of home heating in Libby, the purpose of this study was to determine if amphibole fibers become liberated into the ambient air when amphibole-contaminated firewood is combusted.
Amphibole-contaminated firewood was combusted in new, EPA-certified stoves during three trials. The results of these trials showed that the majority of the fibers remained in the ash following the combustion process, suggesting that additional potential exposures can occur within the homes to those that clean the ash out of woodstoves. The combustion trials also revealed that amphibole fibers can become liberated into the ambient air during the combustion process. Amphibole fibers were found impacted in the ductwork, as well as detected in wipe samples collected from an inverted container used to concentrate the woodsmoke emissions. These findings stress the need for identifying a clean fuel source for the inhabitants of Libby to prevent future exposures
Libby Amphibole Contamination in Tree Bark Surrounding Historical Vermiculite Processing Facilities
Over a 70-year period, a mine near Libby, MT supplied nearly 80% of the world’s vermiculite. Raw vermiculite, which was contaminated with naturally occurring amphibole in veins throughout the deposit, was shipped to processing sites throughout the United States for exfoliation. In this pilot study, tree bark samples were collected near processing facili-ties in Spokane, WA, Santa Ana, CA, Newark, CA, and Phoenix, AZ in an effort to determine if areas surrounding these facilities are today contaminated with Libby amphibole asbestos (AA). From areas surrounding each of the four his-torical processing sites, Libby AA was detected in a subset of the bark samples. At the Santa Ana, Newark and Phoenix facilities, actinolite-tremolite and other high Fe Ca-bearing amphibole were also measured from the bark samples. In addition, chrysotile was frequently measured in samples collected from each of the sites. From the results of this pilot study, it is evident that tree bark can serve as reservoirs of asbestos, and indicators of past and current contamination. These data also suggest that areas outside of these historical processing facilities may today have some level of existing contamination resulting from the operation of these facilities
The Pine Needle, March 1947
Libraries and archives collect materials from different cultures and time periods to preserve and make available the historical record. As a result, materials such as those presented here may reflect sexist, misogynistic, abusive, racist, or discriminatory attitudes or actions that some may find disturbing, harmful, or difficult to view.
Both a humor and literary magazine, The Pine Needle was a University of Maine student-produced periodical that began publication in the fall of 1946, the first post-World War II semester that saw GIs returning to campus.
The Needle reflected an edginess and rebellion not found in previous UMaine student publications. While past student publications relied on euphemisms for alcohol and dating on campus, The Needle overtly sexualized co-eds and discussed the use of drugs, tobacco, and alcohol by students who experienced war.
Cover art for this issue depicts a pen-and-ink illustration by Lloyd Shapleigh (1924-2008), of barefoot man lounging under a tree, reading an issue of New Yorker magazine with a corked jug beside his right elbow.
Lloyd P. Shapleigh, Jr. was born in Bangor, Maine, graduating from high school in 1942 before joining the Army Air Corps during World War II where he qualified as MOE 867-Pathfinder technician and served as a ground crew chief with the 458 Bomb Group (H), 2nd Air Division, 8th Air Force. After the war, Shapleigh used the G.I. Bill to earn Bachelor\u27s Degrees at the University of Maine and Rhode Island School of Design.
Shapleigh eventually joined the industrial design team at Whirlpool where, in 1966, he conducted research testing the feasibility of household trash compaction. The trash compactor became the first new, major household appliance released by the Whirlpool corporation since before the war
Neurokinin B Receptor Antagonism in Women with Polycystic Ovary Syndrome: A Randomized, Placebo-Controlled Trial
Context:
Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women, is characterized by high secretion levels of LH and T. Currently, there is no treatment licensed specifically for PCOS.
Objective:
The objective of this study was to investigate whether a targeted therapy would decrease LH pulse frequency in women with PCOS, subsequently reducing serum LH and T concentrations and thereby presenting a novel therapeutic approach to the management of PCOS.
Design:
This study is a double-blind, double-dummy, placebo-controlled, phase 2 trial.
Settings:
University hospitals and private clinical research centers were included.
Participants:
Women with PCOS aged 18–45 years participated.
Intervention:
Intervention included AZD4901 (a specific neurokinin-3 [NK3] receptor antagonist) at a dose of 20, 40, or 80 mg/day or matching placebo for 28 days.
Main Outcome Measure:
Change from baseline in the area under the LH serum concentration–time curve over 8 hours (area under the curve) on day 7 relative to placebo was measured.
Results:
Of a total 67 randomized patients, 65 were evaluable. On day 7, the following baseline-adjusted changes relative to placebo were observed in patients receiving AZD4901 80 mg/day: 1) a reduction of 52.0% (95% confidence interval [CI], 29.6–67.3%) in LH area under the curve; 2) a reduction of 28.7% (95% CI, 13.9–40.9%) in total T concentration; and 3) a reduction of 3.55 LH pulses/8 hours (95% CI, 2.0–5.1) (all nominal P < .05).
Conclusions:
The NK3 receptor antagonist AZD4901 specifically reduced LH pulse frequency and subsequently serum LH and T concentrations, thus presenting NK3 receptor antagonism as a potential approach to treating the central neuroendocrine pathophysiology of PCOS.
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Pelagic Sargassum events in Jamaica : Provenance, morphotype abundance, and influence of sample processing on biochemical composition of the biomass
Pelagic Sargassum species have been known for centuries in the Sargasso Sea of the North Atlantic Ocean. In 2011, a new area concentrating high biomass of these brown algae started developing in the Tropical Atlantic Ocean. Since then, massive and recurrent Sargassum influxes have been reported in the Caribbean and off the coast of Western Africa. These Sargassum events have a major negative impact on coastal ecosystems and nearshore marine life, and affect socio-economic sectors, including public health, coastal living, tourism, fisheries, andmaritime transport. Despite recent advances in the forecasting of Sargassum events, and elucidation of the seaweed composition, many knowledge gaps remain, including morphotype abundance during Sargassum events, drift of the seaweeds in the months prior to stranding, and influence of sample processing methods on biomass biochemical composition. Using seaweeds harvested on the coasts of Jamaica in summer of 2020,we observed that S. fluitans III was themost abundantmorphotype at different times and sampling locations. No clear difference in the geographical origin, or provenance, of the Sargassummats was observed. Themajority of Sargassumbacktracked fromboth north and south of Jamaica experienced ambient temperatures of around 27 °C and salinity in the range of 34–36 psu before stranding.We also showed that cheap (sun) compared to expensive (freeze) drying techniques influence the biochemical composition of biomass. Sun-drying increased the proportion of phenolic compounds, but had a deleterious impact on fucoxanthin content and on the quantities of monosaccharides, except for mannitol. Effects on the content of fucose containing sulfated polysaccharides depended on the method used for their extraction, and limited variation was observed in ash, protein, and fatty acid content within most of the sample locations investigated. These observations are important for the storage and transport of the biomass in the context of its valorisation
2017 Scientific Consensus Statement: land use impacts on the Great Barrier Reef water quality and ecosystem condition. Chapter 4: management options and their effectiveness
This chapter seeks to answer the following questions:
1. What are the values of the Great Barrier Reef?
2. How effective are better agricultural practices in improving water quality?
3. How can we improve the uptake of better agricultural practices?
4. What water quality improvement can non-agricultural land uses contribute?
5. How can Great Barrier Reef water quality improvement programs be improved?
Each section summarises the currently available peer reviewed literature and comments on implications for management and research gaps.
This chapter has a wider scope than previous Scientific Consensus Statements, including, for the first time, the social and governance dimensions of management and the management of non-agricultural land uses. These new sections are constrained by a lack of Great Barrier Reef–specific data and information. The relevance of information from other locations must be carefully considered. In comparison, the agricultural practice change and economics sections provide an update on material compiled as part of the 2013 Scientific Consensus Statement.
This report has been confined to peer reviewed literature, which is generally published in books and journals or major reports. There is additional evidence in grey literature, such as project and program reports, that has not been included here. Each section of this chapter has been compiled by a writing team and then revised following a series of review processes
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.
Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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