2,108 research outputs found
Effects of an Ammonia-Rich Municipal Sewage Effluent on Iowa River Fauna Near Marshalltown, Iowa
The effect of the Marshalltown municipal sewage effluent on Iowa River water quality and fauna was evaluated from July 1976 through August 1977. The effluent contains high total ammonia and un-ionized ammonia concentrations due to ammonia-rich discharges from meat packinghouses. Dissolved oxygen, pH, temperature, total ammonia nitrogen, and un-ionized ammonia data were collected at.12 sampling stations extending 18 km downstream from the sewage effluent discharge. Wild fish collections were made by using electrofishing, seines, and hoopnets. Thirty-eight fish species were collected during the study. Channel catfish. (Ictalurus punctatus) and smallmouth bass (Micropterus dolomieus) were the most common gamefish. No consistent depression in wild fish diversity was seen below the sewage discharge point. Eight hundred thirty caged channel catfish were used in conducting 13 4-day field toxicityty tests at 5 different river stations. Only 2% mortality was observed. Macroinvertebrate diversity and density were determined by using artificial substrate samplers placed at 5 river stations during 2 3-week exposure periods in the summer of 1976. Macroinvertebrate diversity recovered 770-1550 m downstream from the sewage discharge point. The applicability of the EPA un-ionized ammonia criterion and the Iowa total ammonia nitrogen standard is evaluated in light of the findings from this study
The need for improved management of the subsurface
The subsurface is used intensively to support economic stability and growth. Human interaction with
the shallow subsurface ranges from exploitation of resources, accommodation of utilities, harnessing
of energy (ground source heat pumps) and storage of waste. Current practice of managing these
shallow subsurface zones is far from ideal. Many subsurface interventions are preceded by feasibility
studies, predictive models or investigative measures to mitigate risks or predict the impacts of the
work. However, the complex interactions between the anthropogenic structures and natural processes
mean that a holistic impact assessment is often not achievable. By integrating these subsurface
infrastructures within three dimensional framework models, a comprehensive assessment of the
potential hazards in these shallow subsurface environments may be made. Some Geological Survey
Organizations (GSOs) are currently developing subsurface management systems that will aid decision
making in the shallow subsurface [1]. The British Geological Survey (BGS) is developing an open
Environmental Modeling Platform [2] to provide the data standards and applications to link models,
numerical simulations and ultimately socio-economic models so as to generate predictive responses to
questions concerning sustainable us of the subsurface
Effect of a Cold Margin on Ice Flow at the Terminus of Storglaciaren, Sweden: Implications for Sediment Transfer
The cold-based termini of polythermal glaciers are usually assumed to adhere strongly to an immobile substrate and thereby supply significant resistance to the flow of warm-based ice upglacier. This compressive environment is commonly thought to uplift basal sediment to the surface of the glacier by folding and thrust faulting. We present model and field evidence from the terminus of Storglaciaren, Sweden, showing that the cold margin provides limited resistance to flow from up-glacier. Ice temperatures indicate that basal freezing occurs in this zone at 10−1 –10−2 ma−1, but model results indicate that basal motion at rates greater than 1ma−1 must, nevertheless, persist there for surface and basal velocities to be consistent with measurements. Estimated longitudinal compressive stresses of 20– 25 kPa within the terminus further indicate that basal resistance offered by the cold-based terminus is small. These results indicate that where polythermal glaciers are underlain by unlithified sediments, ice-flow trajectories and sediment transport pathways may be affected by subglacial topography and hydrology more than by the basal thermal regime
Projected 21st century decrease in marine productivity : a multi-model analysis
© Authors, 2010. This work is distributed under
the Creative Commons Attribution 3.0 License. The definitive version was published in Biogeosciences 7 (2010): 979-1005, doi: 10.5194/bg-7-979-2010Changes in marine net primary productivity (PP) and export of particulate organic carbon (EP) are projected over the 21st century with four global coupled carbon cycle-climate models. These include representations of marine ecosystems and the carbon cycle of different structure and complexity. All four models show a decrease in global mean PP and EP between 2 and 20% by 2100 relative to preindustrial conditions, for the SRES A2 emission scenario. Two different regimes for productivity changes are consistently identified in all models. The first chain of mechanisms is dominant in the low- and mid-latitude ocean and in the North Atlantic: reduced input of macro-nutrients into the euphotic zone related to enhanced stratification, reduced mixed layer depth, and slowed circulation causes a decrease in macro-nutrient concentrations and in PP and EP. The second regime is projected for parts of the Southern Ocean: an alleviation of light and/or temperature limitation leads to an increase in PP and EP as productivity is fueled by a sustained nutrient input. A region of disagreement among the models is the Arctic, where three models project an increase in PP while one model projects a decrease. Projected changes in seasonal and interannual variability are modest in most regions. Regional model skill metrics are proposed to generate multi-model mean fields that show an improved skill in representing observation-based estimates compared to a simple multi-model average. Model results are compared to recent productivity projections with three different algorithms, usually applied to infer net primary production from satellite observations.This work was funded by the European
Union projects CARBOOCEAN (511176-2) and EUROCEANS
(511106-2) and is a contribution to the “European Project on
Ocean Acidification” (EPOCA) which received funding from
the European Community’s Seventh Framework Programme
(FP7/2007–2013) under grant agreement no. 211384. Additional
support was received from the Swiss National Science Foundation.
SCD acknowledges support from the NASA Ocean Biology and
Biogeochemistry Program (NNX07AL80G). LB aknowledges support
from the EU Project MEECE (Marine Ecosystem Evolution in
a Changing Environnement, grant agreement 212085)
First Year Physical Activity Findings From Turn up the Heat (Healthy Eating and Activity Time) in Summer Day Camps
Background Summer day camps (SDCs) serve 14 million children yearly in the U.S. and aim to provide participating children with 60 minutes of moderate-to-vigorous physical activity (MVPA). This study evaluated an intervention designed to increase the percent of children meeting this MVPA guideline.
Design Two-group, pre-post quasi-experimental.
Setting/Participants Twenty SDCs serving 1,830 children aged 5–12 years were assigned to MVPA intervention (n = 10) or healthy eating attention control (n = 10).
Intervention
The STEPs (Strategies to Enhance Practice) intervention is a capacity-building approach grounded in the Theory of Expanded, Extended and Enhanced Opportunities. Camp leaders and staff receive training to expand (e.g., introduction of activity breaks/active field trips), extend (e.g., schedule minimum of 3 hours/day for PA opportunities), and enhance (e.g., maximize MVPA children accumulate during schedule activity) activity opportunities. Camps in the comparison condition received support for improving the types of foods/beverages served.
Main outcome measures Percent of children accumulating the 60min/d MVPA guideline at baseline (summer 2015) and post-test (summer 2016) measured via wrist-accelerometry.
Results
Multilevel logistic regression conducted fall 2016 indicated boys and girls attending intervention SDCs were 2.04 (95CI = 1.10,3.78) and 3.84 (95CI = 2.02,7.33) times more likely to meet the 60min/d guideline compared to boys and girls attending control SDCs, respectively. This corresponded to increases of +10.6% (78–89%) and +12.6% (69–82%) in the percentage of boys and girls meeting the guideline in intervention SDCs, respectively. Boys in comparison SDCs increased by +1.6% (81–83%) and girls decreased by -5.5% (76–71%). Process data indicated intervention SDCs successfully extended and enhanced PA opportunities, but were unable to expand PA opportunities, compared to control SDCs.
Conclusions
Although substantial proportions of children met the MVPA guideline at baseline, no SDCs ensured all children met the guideline. This intervention demonstrated that, with support, SDCs can help all children in attendance to accumulate their daily recommended 60min MVPA.
Trial registration
ClinicalTrials.gov NCT0216180
FUS (fused in sarcoma) is a component of the cellular response to topoisomerase I–induced DNA breakage and transcriptional stress
FUS (fused in sarcoma) plays a key role in several steps of RNA metabolism, and dominant mutations in this protein are associated with neurodegenerative diseases. Here, we show that FUS is a component of the cellular response to topoisomerase I (TOP1)–induced DNA breakage; relocalising to the nucleolus in response to RNA polymerase II (Pol II) stalling at sites of TOP1-induced DNA breaks. This relocalisation is rapid and dynamic, reversing following the removal of TOP1-induced breaks and coinciding with the recovery of global transcription. Importantly, FUS relocalisation following TOP1-induced DNA breakage is associated with increased FUS binding at sites of RNA polymerase I transcription in ribosomal DNA and reduced FUS binding at sites of RNA Pol II transcription, suggesting that FUS relocates from sites of stalled RNA Pol II either to regulate pre-mRNA processing during transcriptional stress or to modulate ribosomal RNA biogenesis. Importantly, FUS-mutant patient fibroblasts are hypersensitive to TOP1-induced DNA breakage, highlighting the possible relevance of these findings to neurodegeneration
PARP-1 dependent recruitment of the amyotrophic lateral sclerosis-associated protein FUS/TLS to sites of oxidative DNA damage
Amyotrophic lateral sclerosis (ALS) is associated with progressive degeneration of motor neurons. Several of the genes associated with this disease encode proteins involved in RNA processing, including fused-in-sarcoma/translocated-in-sarcoma (FUS/TLS). FUS is a member of the heterogeneous nuclear ribonucleoprotein (hnRNP) family of proteins that bind thousands of pre-mRNAs and can regulate their splicing. Here, we have examined the possibility that FUS is also a component of the cellular response to DNA damage. We show that both GFP-tagged and endogenous FUS re-localize to sites of oxidative DNA damage induced by UVA laser, and that FUS recruitment is greatly reduced or ablated by an inhibitor of poly (ADP-ribose) polymerase activity. Consistent with this, we show that recombinant FUS binds directly to poly (ADP-ribose) in vitro, and that both GFP-tagged and endogenous FUS fail to accumulate at sites of UVA laser induced damage in cells lacking poly (ADP-ribose) polymerase-1. Finally, we show that GFP-FUS(R521G), harbouring a mutation that is associated with ALS, exhibits reduced ability to accumulate at sites of UVA laser-induced DNA damage. Together, these data suggest that FUS is a component of the cellular response to DNA damage, and that defects in this response may contribute to ALS
An assessment of temporal, spatial and taxonomic trends in harmful algal toxin exposure in stranded marine mammals from the US New England coast
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Fire, S. E., Bogomolni, A., DiGiovanni, R. A., Jr., Early, G., Leighfield, T. A., Matassa, K., Miller, G. A., Moore, K. M. T., Moore, M., Niemeyer, M., Pugliares, K., Wang, Z., & Wenzel, F. W. An assessment of temporal, spatial and taxonomic trends in harmful algal toxin exposure in stranded marine mammals from the US New England coast. Plos One, 16(1),(2021): e0243570, https://doi.org/10.1371/journal.pone.0243570.Despite a long-documented history of severe harmful algal blooms (HABs) in New England coastal waters, corresponding HAB-associated marine mammal mortality events in this region are far less frequent or severe relative to other regions where HABs are common. This long-term survey of the HAB toxins saxitoxin (STX) and domoic acid (DA) demonstrates significant and widespread exposure of these toxins in New England marine mammals, across multiple geographic, temporal and taxonomic groups. Overall, 19% of the 458 animals tested positive for one or more toxins, with 15% and 7% testing positive for STX and DA, respectively. 74% of the 23 different species analyzed demonstrated evidence of toxin exposure. STX was most prevalent in Maine coastal waters, most frequently detected in common dolphins (Delphinus delphis), and most often detected during July and October. DA was most prevalent in animals sampled in offshore locations and in bycaught animals, and most frequently detected in mysticetes, with humpback whales (Megaptera novaeangliae) testing positive at the highest rates. Feces and urine appeared to be the sample matrices most useful for determining the presence of toxins in an exposed animal, with feces samples having the highest concentrations of STX or DA. No relationship was found between the bloom season of toxin-producing phytoplankton and toxin detection rates, however STX was more likely to be present in July and October. No relationship between marine mammal dietary preference and frequency of toxin detection was observed. These findings are an important part of a framework for assessing future marine mammal morbidity and mortality events, as well as monitoring ecosystem health using marine mammals as sentinel organisms for predicting coastal ocean changes.S.F. - NOAA John H. Prescott Marine Mammal Rescue Assistance Grant Program #NA16NMF4390151 S.F. - NOAA John H. Prescott Marine Mammal Rescue Assistance Grant Program #NA17NMF4390082 S.F. - Florida Tech Department of Biological Sciences S.F. - Florida Tech John H. Evans Library Open Access Subvention Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Atomic Dark Matter
We propose that dark matter is dominantly comprised of atomic bound states.
We build a simple model and map the parameter space that results in the early
universe formation of hydrogen-like dark atoms. We find that atomic dark matter
has interesting implications for cosmology as well as direct detection:
Protohalo formation can be suppressed below for weak scale dark matter due to Ion-Radiation interactions in the
dark sector. Moreover, weak-scale dark atoms can accommodate hyperfine
splittings of order 100 \kev, consistent with the inelastic dark matter
interpretation of the DAMA data while naturally evading direct detection
bounds.Comment: 17 pages, 3 figure
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