955 research outputs found

    Dynamic-model study of planetary-entry configurations in the Langley spin tunnel

    Get PDF
    Dynamic model study to determine low subsonic speed stability and drag characteristics during vertical descent of entry configurations considered for probes of planetary atmosphere

    Investigation into the effects of an after school GEPA math program in raising student achievement

    Get PDF
    The intent of this paper is to determine the effectiveness of an after school math program on raising student achievement on the Grade Eight Proficiency Assessment (GEPA). Regular education students were selected based on a review of their fourth grade standardized test, and the trend in their yearly Terra Nova scores from 5th , 6th and 7th grade, if available. Based on a proficient score of 200, students who scored in the range of 185 to 210 were invited to attend the eighteen-week after school program. In addition, all special education students were invited to attend. Forty-five students elected to participate in the voluntary program. Students took a pretest at the onset of the program and a posttest at the conclusion and results were tabulated and analyzed. The results supported the continuation of the after school program for both populations of students. The percentage change calculation in student scores on the pretest and posttest provided evidence of the program\u27s effectiveness. One major variable, student participation rate was analyzed to help determine the relationship between performance and attendance. The data suggests that those students who attended greater than fifty percent of the time showed a marked improvement over those students who attended less than fifty percent

    Discriminating Between Apoptosis, Necrosis, Necroptosis, and Ferroptosis by Microscopy and Flow Cytometry

    Get PDF
    Funding Information: The Martin laboratory is supported by an ERC Advanced grant (101020534, DESTRESS) as well as an Irish Research Council Advanced Laureate Award (IRCLA/2019/133). The Hollville laboratory is supported by a Royal Society Research grant (RG16955).Peer reviewedPublisher PD

    Regulation of Phytochrome Gene Expression

    Get PDF
    In etiolated oat seedlings exposure to red light results in a decrease in the transcription of the phytochrome genes, the abundance of phytochrome mRNA, and the level of phytochrome protein. Phytochrome itself serves as the photoreceptor for the response of decreased mRNA and transcription levels. The decrease in phytochrome mRNA is sensitive to low levels of Pfr. Even green safelight is capable of inducing a decrease in phytochrome mRNA abundance. Barley phytochrome mRNA abundance is also dramatically down-regulated in response to red light but other plant species vary in their ability to decrease phytochrome mRNA abundance after red light treatment. Kinetic analysis and protein synthesis inhibitor data indicate that the abundance of phytochrome mRNA in oat seedlings may be regulated in part at the post-transcriptional level. Phytochrome mRNA may provide a useful model system for the investigation of posttranscriptional regulation of plant gene expression

    How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation

    Get PDF
    Citation: Fencl, J. S., Mather, M. E., Costigan, K. H., & Daniels, M. D. (2015). How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation. Plos One, 10(11), 22. doi:10.1371/journal.pone.0141210Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0-15.3 km) or 287 wetted widths (136437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach that has been applied to larger dams

    Mas-related G-protein–coupled receptors inhibit pathological pain in mice

    Get PDF
    An important objective of pain research is to identify novel drug targets for the treatment of pathological persistent pain states, such as inflammatory and neuropathic pain. Mas-related G-protein–coupled receptors (Mrgprs) represent a large family of orphan receptors specifically expressed in small-diameter nociceptive primary sensory neurons. To determine the roles of Mrgprs in persistent pathological pain states, we exploited a mouse line in which a chromosomal locus spanning 12 Mrgpr genes was deleted (KO). Initial studies indicated that these KO mice show prolonged mechanical- and thermal-pain hypersensitivity after hind-paw inflammation compared with wild-type littermates. Here, we show that this mutation also enhances the windup response of dorsal-horn wide dynamic-range neurons, an electrophysiological model for the triggering of central pain sensitization. Deletion of the Mrgpr cluster also blocked the analgesic effect of intrathecally applied bovine adrenal medulla peptide 8–22 (BAM 8–22), an MrgprC11 agonist, on both inflammatory heat hyperalgesia and neuropathic mechanical allodynia. Spinal application of bovine adrenal medulla peptide 8–22 also significantly attenuated windup in wild-type mice, an effect eliminated in KO mice. These data suggest that members of the Mrgpr family, in particular MrgprC11, may constitute an endogenous inhibitory mechanism for regulating persistent pain in mice. Agonists for these receptors may, therefore, represent a class of antihyperalgesics for treating persistent pain with minimal side effects because of the highly specific expression of their targets

    Delayed gastric emptying and reduced postprandial small bowel water content of equicaloric whole meal bread versus rice meals in healthy subjects: novel MRI insights

    Get PDF
    BACKGROUND/OBJECTIVES: Postprandial bloating is a common symptom in patients with functional gastrointestinal (GI) diseases. Whole meal bread (WMB) often aggravates such symptoms though the mechanisms are unclear. We used magnetic resonance imaging (MRI) to monitor the intragastric fate of a WMB meal (11% bran) compared to a rice pudding (RP) meal. SUBJECTS/METHODS: 12 healthy volunteers completed this randomised crossover study. They fasted overnight and after an initial MRI scan consumed a glass of orange juice with a 2267 kJ WMB or an equicaloric RP meal. Subjects underwent serial MRI scans every 45 min up to 270 min to assess gastric volumes and small bowel water content and completed a GI symptom questionnaire. RESULTS: The MRI intragastric appearance of the two meals was markedly different. The WMB meal formed a homogeneous dark bolus with brighter liquid signal surrounding it. The RP meal separated into an upper, liquid layer and a lower particulate layer allowing more rapid emptying of the liquid compared to solid phase (sieving). The WMB meal had longer gastric half emptying times (132±8 min) compared to the RP meal (104±7 min), P<0.008. The WMB meal was associated with markedly reduced MRI-visible small bowel free mobile water content compared to the RP meal, P<0.0001. CONCLUSIONS: WMB bread forms a homogeneous bolus in the stomach which inhibits gastric sieving and hence empties slower than the equicaloric rice meal. These properties may explain why wheat causes postprandial bloating and could be exploited to design foods which prolong satiation

    The disappearing act: a dusty wind eclipsing RW Aur

    Get PDF
    The authors acknowledge support from the Science and Technology Facilities Council through grants no. ST/K502339/1 and ST/M001296/1, and the Science Foundation Ireland through grant no. 10/RFP/AST2780.RW Aur is a young binary star that experienced a deep dimming in 2010-11in component A and a second even deeper dimming from summer 2014 to summer 2016. We present new unresolved multi-band photometry during the 2014-16 eclipse, new emission line spectroscopy before and during th dimming, archive infrared photometry between 2014-15, as well as an overview of literature data. Spectral observations were carried out witht he Fibre-fed RObotic Dual-beam Optical Spectrograph on the Liverpool Telescope. Photometric monitoring was done with the Las Cumbres Observatory Global Telescope Network and James Gregory Telescope. Ourphotometry shows that RW Aur dropped in brightness to R = 12.5 in March 2016. In addition to the long-term dimming trend, RW Aur is variable on time-scales as short as hours. The short-term variation is most likely due to an unstable accretion flow. This, combined with the presence of accretion-related emission lines in the spectra suggest that accretion flows in the binary system are at least partially visible during the eclipse. The equivalent width of [O I] increases by a factor of ten in 2014, coinciding with the dimming event, confirming previous reports.The blueshifted part of the Hα profile is suppressed during the eclipse. In combination with the increase in mid-infrared brightness during the eclipse reported in the literature and seen in WISE archival data, and constraints on the geometry of the disk around RW Aur A we arrive at the conclusion that the obscuring screen is part of a wind emanating from the inner disc.Publisher PDFPeer reviewe
    corecore