4,826 research outputs found

    Bacterial diversity impacts as a result of combined sewer overflow in a polluted waterway

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    Newtown Creek is an industrial waterway and former tidal wetland in New York City. It is one of the most polluted water bodies in the United States and was designated as a superfund site in 2010. For over a century, organic compounds, heavy metals, and other forms of industrial pollution have disrupted the creek’s environment. The creek is also impacted by discharges from twenty combined sewer overflow pipes, which may deposit raw sewage or partially treated wastewater directly into the creek during heavy or sustained rain events. Combined sewer overflow events and associated nutrient over-enrichment at the creek drive eutrophication and subsequent hypoxia. At the current study, three sites were sampled one week apart during a dry period and a wet period, where indication of a combined sewage overflow event could be detected. 16s rRNA high-throughput sequencing from these three sites collectively yielded over 1000 species of bacteria belonging to twenty-two classes. Based on these data, it is hypothesized that differences identified in the microbiome on wet versus dry days are as a result of combined sewage overflow, street runoff, and additional fluctuations in the creek’s environment associated with rain. It was found that after a combined sewer overflows event, the levels of Gamma Proteobacteria increased while the levels of Actinobacteria decreased. However, levels of bacteria stayed relatively unchanged at a site further away from combined sewer overflows discharge. Species found in Newtown Creek include pelagic, marine, human and animal pathogens, hydrocarbonoclastic, and other environmental microbes

    Inconvenient Truth About Boise Public Transportation

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    The Boise-Nampa metropolitan area is growing rapidly, and its transportation system must expand to account for this growth. However, in order for a public transportation system to be effective, citizens must have both the ability and the incentive to make use of it. Our research will focus on the demand for public transit in the Boise-Nampa metropolitan area. First, we will determine current ridership on the existing public transit system, frequency of use, reasons for using mass transit over other alternative modes of transportation, and what attributes of the system make it an attractive option. Next, we will determine what attributes of the system the public finds most problematic or inconvenient, and we will use this information to recommend policies and level-of-service adjustments that could make the system more user-friendly and efficient. Our research will examine the public’s awareness of available public transit options and the image that the current system projects in the public consciousness, and suggest measures for improvement where necessary

    Vertical And Horizontal Integration Of Laboratory Curricula And Course Projects Across The Electronic Engineering Technology Program

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    This paper discusses the details of the curricular development effort with a focus on the vertical and horizontal integration of laboratory curricula and course projects within the Electronic Engineering Technology (EET) program at Texas A&M University. Both software and hardware aspects are addressed. A common set of software tools are introduced to the sophomore students in the EET curriculum; these tools are then used in several junior and senior level courses. Through early and repeated exposure to these tools, students learn to use them more effectively to solve various engineering problems in laboratory and course projects. A DC permanent magnetic motor is identified as one of the common hardware platforms for multiple course projects. By using a common platform for different course projects, the students can spend much less time preparing for the course projects. With each course adding different features to the common platform, the learning experience in several courses becomes seamlessly integrated. Surveys were conducted to show that the curriculum development effort improved the efficiency of student learning and enhanced the students’ educational experience.

    Belted sum decompositions of fully augmented links

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    Given two orientable, cusped hyperbolic 3-manifolds containing certain thrice-punctured spheres, Adams gave a diagrammatic definition for a third such manifold, their belted sum. Fully augmented links, or FALs, are hyperbolic links constructed by augmenting a link diagram. This work considers belted sum decompositions in which all manifolds involved are FAL complements. To do so, we provide explicit classifications of thrice punctured spheres in FAL complements, making them easily recognizable. These classifications are used to characterize belted sum prime FALs geometrically, combinatorially and diagrammatically. Finally we prove that, in the context of belted sums, every FAL complement canonically decomposes into FALs which are either prime or two-fold covers of the Whitehead link

    Reversal of aging-induced increases in aortic stiffness by targeting cytoskeletal protein-protein interfaces

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    BACKGROUND: The proximal aorta normally functions as a critical shock absorber that protects small downstream vessels from damage by pressure and flow pulsatility generated by the heart during systole. This shock absorber function is impaired with age because of aortic stiffening. METHODS AND RESULTS: We examined the contribution of common genetic variation to aortic stiffness in humans by interrogating results from the AortaGen Consortium genome‐wide association study of carotid‐femoral pulse wave velocity. Common genetic variation in the N‐WASP (WASL) locus is associated with carotid‐femoral pulse wave velocity (rs600420, P=0.0051). Thus, we tested the hypothesis that decoy proteins designed to disrupt the interaction of cytoskeletal proteins such as N‐WASP with its binding partners in the vascular smooth muscle cytoskeleton could decrease ex vivo stiffness of aortas from a mouse model of aging. A synthetic decoy peptide construct of N‐WASP significantly reduced activated stiffness in ex vivo aortas of aged mice. Two other cytoskeletal constructs targeted to VASP and talin‐vinculin interfaces similarly decreased aging‐induced ex vivo active stiffness by on‐target specific actions. Furthermore, packaging these decoy peptides into microbubbles enables the peptides to be ultrasound‐targeted to the wall of the proximal aorta to attenuate ex vivo active stiffness. CONCLUSIONS: We conclude that decoy peptides targeted to vascular smooth muscle cytoskeletal protein‐protein interfaces and microbubble packaged can decrease aortic stiffness ex vivo. Our results provide proof of concept at the ex vivo level that decoy peptides targeted to cytoskeletal protein‐protein interfaces may lead to substantive dynamic modulation of aortic stiffness.Published versio

    Little ecological divergence associated with speciation in two African rain forest tree genera

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    <p>Abstract</p> <p>Background</p> <p>The tropical rain forests (TRF) of Africa are the second largest block of this biome after the Amazon and exhibit high levels of plant endemism and diversity. Two main hypotheses have been advanced to explain speciation processes that have led to this high level of biodiversity: allopatric speciation linked to geographic isolation and ecological speciation linked to ecological gradients. Both these hypotheses rely on ecology: in the former conservation of ecological niches through time is implied, while in the latter adaptation via selection to alternative ecological niches would be a prerequisite. Here, we investigate the role of ecology in explaining present day species diversity in African TRF using a species level phylogeny and ecological niche modeling of two predominantly restricted TRF tree genera, <it>Isolona </it>and <it>Monodora </it>(Annonaceae). Both these genera, with 20 and 14 species, respectively, are widely distributed in African TRFs, with a few species occurring in slightly less humid regions such as in East Africa.</p> <p>Results</p> <p>A total of 11 sister species pairs were identified most of them occurring in allopatry or with little geographical overlap. Our results provide a mixed answer on the role of ecology in speciation. Although no sister species have identical niches, just under half of the tests suggest that sister species do have more similar niches than expected by chance. PCA analyses also support little ecological differences between sister species. Most speciation events within both genera predate the Pleistocene, occurring during the Late Miocene and Pliocene periods.</p> <p>Conclusions</p> <p>Ecology is almost always involved in speciation, however, it would seem to have had a little role in species generation within <it>Isolona </it>and <it>Monodora </it>at the scale analyzed here. This is consistent with the geographical speciation model for TRF diversification. These results contrast to other studies for non-TRF plant species where ecological speciation was found to be an important factor of diversification. The Pliocene period appears to be a vital time in the generation of African TRF diversity, whereas Pleistocene climatic fluctuations have had a smaller role on speciation than previously thought.</p> <p>Ecological niche modeling, species level phylogeny, ecological speciation, African tropics, <it>Isolona</it>, <it>Monodora</it>, Annonaceae</p

    Deep Space Habitat Wireless Smart Plug

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    NASA has been interested in technology development for deep space exploration, and one avenue of developing these technologies is via the eXploration Habitat (X-Hab) Academic Innovation Challenge. In 2013, NASA's Deep Space Habitat (DSH) project was in need of sensors that could monitor the power consumption of various devices in the habitat with added capability to control the power to these devices for load shedding in emergency situations. Texas A&M University's Electronic Systems Engineering Technology Program (ESET) in conjunction with their Mobile Integrated Solutions Laboratory (MISL) accepted this challenge, and over the course of 2013, several undergraduate students in a Capstone design course developed five wireless DC Smart Plugs for NASA. The wireless DC Smart Plugs developed by Texas A&M in conjunction with NASA's Deep Space Habitat team is a first step in developing wireless instrumentation for future flight hardware. This paper will further discuss the X-Hab challenge and requirements set out by NASA, the detailed design and testing performed by Texas A&M, challenges faced by the team and lessons learned, and potential future work on this design

    Searching for keV Sterile Neutrino Dark Matter with X-ray Microcalorimeter Sounding Rockets

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    High-resolution X-ray spectrometers onboard suborbital sounding rockets can search for dark matter candidates that produce X-ray lines, such as decaying keV-scale sterile neutrinos. Even with exposure times and effective areas far smaller than XMM-Newton and Chandra observations, high-resolution, wide field-of-view observations with sounding rockets have competitive sensitivity to decaying sterile neutrinos. We analyze a subset of the 2011 observation by the X-ray Quantum Calorimeter instrument centered on Galactic coordinates l = 165, b = -5 with an effective exposure of 106 seconds, obtaining a limit on the sterile neutrino mixing angle of sin^2(2 theta) < 7.2e-10 at 95% CL for a 7 keV neutrino. Better sensitivity at the level of sin^2(2 theta) ~ 2.1e-11 at 95\% CL for a 7 keV neutrino is achievable with future 300-second observations of the galactic center by the Micro-X instrument, providing a definitive test of the sterile neutrino interpretation of the reported 3.56 keV excess from galaxy clusters.Comment: 13 pages, 13 figures, submitted to Ap

    A Comparison of ChĂątelperronian and Protoaurignacian Core Technology Using Data Derived from 3D Models

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    This study uses data extracted from 3D models to compare blade cores from the Chùtelperronian and Protoaurignacian stone tool industries. These technocomplexes are at the center of the debate surrounding the interactions between Neanderthals and anatomically modern humans approximately 45 to 40,000 years ago. We created 3D models of lithic cores from the sites of Roc de Combe and Les Cottés using a standardized photogrammetry protocol. We then used data derived from these 3D models to make quantitative comparisons of artifact attributes that have previously been argued to distinguish the two stone tool industries in question. These attributes include the angle between the platform and flaking surfaces, the shape of core cross sections, and the angle between core axes. The conception of this study was not to privilege the use of new technological and statistical approaches over more traditional or qualitative forms of lithic analysis. Rather, our aim was to experiment with using digital tool to develop nuanced, reproducible ways to describe variability in lithic artifacts. Our results support the hypothesis that there is a difference in the angle between core surfaces between these two industries. Our analysis also indicates a difference in the angle between core axes, although we are more cautious in interpreting these results. An elliptical Fourier analysis of core cross section shape was inconclusive. We discuss what archaeological and methodological factors may have contributed to our results, and the roles of both qualitative and quantitative observations in archaeological research. 3D artifact models generated for this study are included as supplemental data and are available for use by other researchers
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