1,412 research outputs found
Little Higgs models and single top production at the LHC
We investigate the corrections of the littlest Higgs(LH) model and the SU(3)
simple group model to single top production at the CERN Large Hardon
Collider(LHC). We find that the new gauge bosons predicted by the
LH model can generate significant contributions to single top production via
the s-channel process. The correction terms for the tree-level couplings
coming from the SU(3) simple group model can give large contributions to the
cross sections of the t-channel single top production process. We expect that
the effects of the LH model and the SU(3) simple group model on single top
production can be detected at the LHC experiments.Comment: 17pages, 5 figures, discussions and references added, typos correcte
The Impact of #365Papers: A Daily Scientific Twitter Campaign to Disseminate Exercise Oncology Literature
Purpose: Many health researchers and practitioners use Twitter to stimulate scientific dialogue and collaboration among peers, as well as the general public. In 2018, the Clinical Exercise Physiology Lab (CEPL) undertook a year-long scientific Twitter campaign (#365Papers) where one peer-reviewed publication related to cancer and exercise/physical activity was tweeted per day. Features of this campaign included Throwback Thursdays (selected article published before 2018) and guest tweeters (article chosen by other exercise oncology researchers). We report on the impact of the #365Papers campaign based on Twitter Analytics data (i.e., engagement rate). We also explore how engagement rate differed depending on publication features (e.g., type of research, journal impact factor, Altmetric Attention Score) and campaign features (i.e., Throwback Thursdays, guest tweeters). Methods: Campaign data were obtained from Twitter Analytics (Twitter, 2020: San Francisco, USA). Publication information (i.e., type of research, journal) was extracted by screening titles and abstracts, while each publication’s Altmetric Attention Score was obtained using the Altmetric Bookmarklet (Digital Science, Holtzbrinck Publishing Group, 2020: Stuttgart, Germany). Twitter Analytics data were summarized using descriptive statistics. Differences in engagement rate were analyzed based on research type (e.g., randomized controlled trial), journal impact factor, Altmetric Attention Score, and if the publication was posted as part of a Throwback Thursday or by a guest tweeter. Results: The #365Papers Twitter campaign received a total of 688,117 impressions and 22,124 engagements, with a median engagement rate of 3.2% and the majority of engagement from URL clicks (n=8279; 37%). The mean monthly increase in CEPL Twitter account followers was 48 (±18). Engagement rate did not differ based on type of research (p=0.53), journal impact factor (r=-0.06; p=0.27), Altmetric Attention Score (r=0.01; p=0.80), nor if the tweet was part of a Throwback Thursday (p=0.97). However, guest tweets had significantly higher engagement rates versus non-guest tweets (median: 3.6% vs. 3.1%; p=0.01). Conclusion: Our findings suggest the potential of a daily scientific Twitter campaign to stimulate peer and public engagement and dialogue around new scientific publications, especially when prominent figures in the research field are incorporated into the campaign process
Hydromorphological control of phosphorus in a large free-flowing gravel bed river: the Garonne river (France)
The objective of this paper is to relate phosphorus (P) transport dynamics and hydromorphological characteristics of a large human-influenced river, the River Garonne within a sector receiving the waste water of a sewage treatment plant for a population of 600 000. Two studies were conducted in 1997 and 1999 during two different hydrological conditions at low-flow periods. The 1997 study was carried out on an 18-km stretch with discharges varying between 33 and 53 m3/s and with very small fluctuations. The 1999 study concerned a longer stretch of 47 km, divided into four smaller reaches, and with discharges fluctuating rapidly from 40 to 108 m3/s.
Downstream of the sewage treatment plant, total phosphorus (TP) concentrations ranged from 0.19 to 0.27 mg/L and were mainly in the dissolved form: between 60 and 78% of TP was dissolved reactive phosphorus (DRP). P concentrations were significantly lower upstream of the sewage treatment plant.
By a mass-balance approach, we estimated that the sewage treatment plant represents more than half the input (between 59 and 67%) of the studied sector. TP dynamic is linked to suspended solids for discharges above 60 m3/s.
During established low-flow period in the 1997 study (<60 m3/s), 22 and 27% of TP and DRP were retained by the river bed.
In the 1999 study, under different low-water period hydraulic conditions, we calculate that particulate P retention occurred in two reaches among the four under study and only for discharges below 60 m3/s.
We show that for established discharges below 60 m3/s, there is an active uptake of transported P by functional compartments (i.e. the hyporheic zone and the periphyton). During the low-water period with relatively high hydraulic fluctuations, and for discharges >60 m3/s, P retention is controlled as expected by suspended matter dynamics
Safety and Organization: An EPICS Partnership With Habitat for Humanity
The student authors of this essay are a group of eight participating in the Engineering Projects in Community Service (EPICS) program on the Habitat for Humanity (HFH) team. In this article, they describe how they have improved the working conditions within the loft space of the local Habitat for Humanity office in Lafayette, Indiana. Their work is intended to permanently improve the safety conditions of the loft, as well as the organization of the equipment within the loft. The specific safety concerns addressed by the HFH team include horizontal steel trusses at head level and an unprotected access opening in the railing of the loft. The organizational change includes the installation of two units to organize signs used for construction sites and events
MALDI Matrix Application Utilizing a Modified 3D Printer for Accessible High Resolution Mass Spectrometry Imaging
Successful matrix-assisted
laser desorption ionization (MALDI)
mass spectrometry imaging (MSI) relies on the selection of the most
appropriate matrix and optimization of the matrix application parameters.
In order to achieve reproducible high spatial-resolution imaging data,
several commercially available automated matrix application platforms
have become available. However, the high cost of these commercial
matrix sprayers is restricting access into this emerging research
field. Here, we report an automated platform for matrix deposition,
employing a converted commercially available 3D printer ($300) and
other parts commonly found in an analytical chemistry lab alow-cost
alternative to commercial sprayers. Using printed fluorescent rhodamine
B microarrays and employing experimental design, the matrix deposition
parameters were optimized to minimize surface analyte diffusion. Finally,
the optimized matrix application method was applied to image three-dimensional
MCF-7 cell culture spheroid sections (ca. 500 μm diameter tissue
samples) and sections of mouse brain. Using this system, we demonstrate
robust and reproducible observations of endogenous metabolite and
steroid distributions with a high spatial resolution
A Benefit And Cost Analysis Of A Ground To Air Heat Transfer System (GAHT®)
A media res BCA report was conducted on a Ground to Air Heat Transfer System (GAHT®) currently being Constructed by Appalachian State University. The GAHT® system was purchased from Ceres Greenhouse Solutions and was found to be identical to Closed Loop Earth to Air Heat Transfer Systems (EAHTS) in the literature. EAHTS utilize the soil’s temperature beneath or around a structure to heat or cool an interior space by pumping air in underground tunnels or pipes buried underground. EAHTS were found to have higher installation costs yet lower operational costs than the other heating alternatives. No study has been done to the knowledge of the author that investigated the installation of an EAHTS from a BCA perspective and that here was little information available to prospective consumers about the profitability of an investment in EAHTS technology. This BCA focused solely on the heating ability of the GAHT® system. The study concluded that net benefits of the GAHT are generally positive, but this result is dependent on many variables. When assuming a 0% discount rate, Net Benefits of the GAHT® system are -1,434.33 with no payback period within the 20 year time horizon of the study. The study also found a wide variation in these calculations based on the assumed inputs, ranging from a payback period of 39.34 to 7.27 years, and a net benefit of 18,280.80. The BCA report created information that prospective consumers can use while considering investments in EAHTS technology. Future areas of research include a deeper investigation in the cooling abilities of the GAHT® system
Who participates in local government? Evidence from meeting minutes
Scholars and policymakers have highlighted institutions that enable community participation as a potential buffer against existing political inequalities. Yet these venues may bias policy discussions in favor of an unrepresentative group of individuals. To explore who participates, we compile a novel data set by coding thousands of instances of citizens speaking at planning and zoning board meetings concerning housing development. We match individuals to a voter file to investigate local political participation in housing and development policy. We find that individuals who are older, male, longtime residents, voters in local elections, and homeowners are significantly more likely to participate in these meetings. These individuals overwhelmingly (and to a much greater degree than the general public) oppose new housing construction. These participatory inequalities have important policy implications and may be contributing to rising housing costs.Accepted manuscrip
Geological imprint of methane seepage on the seabed and biota of the convergent Hikurangi Margin, New Zealand: box core and grab carbonate results
Short box cores (to 30 cm bsf) and seafloor carbonate grab samples were acquired at mapped hydrocarbon seep sites (600–1200 m water depths) during the 2007 RV SONNE SO191 cruise on the Hikurangi Margin offshore eastern North Island, New Zealand, to evaluate the influence of methane seepage on sedimentologic, biotic, mineralogic and stable isotopic attributes of seabed sediments. Sedimentary horizons in the box cores consist of siliciclastic silts and sands, shell beds and nodular, microcrystalline aragonite bands up to 15 cm thick. The megafauna is dominated by infaunal to semi-infaunal chemosymbiotic bivalves (Calyptogena, Lucinoma, and Acharax), as well as associated worms and carnivorous and grazing gastropods. Burrows in silts, some occupied by worms or juvenile Acharax, mainly have simple morphologies more typical of high-energy, nearshore settings than deep-sea environments, while a few are large and sparsely branched with wall scratch marks inferred to be of decapod crustacean origin.
The box core silts and nodular carbonate samples vary in TOC content from 0.2 to 0.9 wt.%, carbonate content from 4 to 78%, and δ13C and δ18O values from − 50.3 to − 0.6‰ PDB and + 0.77 to + 3.2‰ PDB, respectively. Low carbonate content silt samples have the most enriched δ13C values, implying a seawater source for their pore water bicarbonate. Negative δ13C and positive δ18O values typify the nodular, microcrystalline aragonite bands, indicating formation during microbially mediated, sulphate-dependent anaerobic oxidation of methane (AOM) in a cold, near-seafloor environment, as is also supported by lipid biomarker data. A clear isotopic mixing trend of decreasing δ13C and increasing δ18O and carbonate content in the fine (< 100 µm) carbonate fraction of the host silts also has been reported from other methane seep provinces, and suggests a heterogeneous influx of methane-rich see
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