4,434 research outputs found

    Comments on the nature of the outside boundary layer on a liquid sphere in a steady, uniform stream

    Get PDF
    Nature of outside boundary layer on liquid sphere in steady, uniform strea

    Malathion Resistance in Larvae of Some Southern Minnesota Populations of the Indianmeal Moth,\u3ci\u3e Plodia Interpunctella\u3c/i\u3e (Lepidoptera: Pyralidae), Infesting Bulk-Stored Shelled Corn

    Get PDF
    Larvae of 21 field collected populations of the Indianmeal moth, Plodia interpunctella, infesting stored shelled corn in southern Minnesota were tested for their susceptibility to malathion in the laboratory. A population that was a composite of the 21 populations and a malathion susceptible population were also tested for their susceptibility to malathion, pirimiphos-methyl and chlorpyrifos-methyl. Comparison of the LDso values of the field populations with the malathion susceptible population indicated that the field populations were ca. 33- to 625-fold resistant to malathion. The composite field population was ca. 243-fold resistant to malathion, and this population was 3.2-fold cross-resistant to pirimiphos-methyl, but was highly susceptible to chlorpyrifos-methyl

    Third parties in twentieth century American politics

    Get PDF
    Not availabl

    Overcoming the hurdles: Understanding motivation and supporting adult learners with poor literacy and dyslexia in the homelessness sector

    Get PDF
    Literacy difficulties are often reported by adults with experience of homelessness. Yet, research on their learning experiences and clarity on how best to support this group is lacking. The present study explored the experience of homeless literacy learners (HLLs) and asked what motivated them to engage with literacy support and the teaching‐related factors perceived to be most effective. Semi‐structured interviews were conducted with 10 HLLs (aged 31–68) engaged in literacy provision at a homelessness charity in the United Kingdom. Thematic analysis of the data revealed five key themes: challenging early experiences; barriers to improving literacy; the perceived impact of poor literacy; current motivation to improve literacy; and approaches that support literacy in adulthood. A significant majority of HLLs reported early traumatic learning experiences and 7 out of 10 (70%) disclosed a diagnosis of dyslexia. Specialist dyslexia support was reported to help HLLs feel understood and positive relationships with teachers helped self‐esteem and self‐efficacy related to their literacy learning. Recommendations are made for specialist teachers to be made more readily available to support HLLs, as well as to advise service providers and professionals engaging with adult learners with experience of homelessness across the sector

    Persistent postural perceptual dizziness is on a spectrum in the general population

    Get PDF
    Objective To examine the idea that symptoms of persistent postural perceptual dizziness (PPPD) are more common than previously assumed and lie on a spectrum in the general population, thus challenging current theories that PPPD is only a consequence of a vestibular insult. Methods We collected 2 common clinical questionnaires of PPPD (Visual Vertigo Analogue Scale [VVAS] and Situational Characteristics Questionnaire [SCQ]) in 4 cohorts: community research volunteers (n = 1941 for VVAS, n = 1,474 for SCQ); paid online participants (n = 190 for VVAS, n = 125 for SCQ); students (n = 204, VVAS only); and patients diagnosed with PPPD (n = 25). Results We found that around 9%, 4%, and 11%, respectively, of the 3 nonclinical cohorts scored above the 25th percentile patient score on 1 PPPD measure (VVAS) and 49% and 54% scored above the 25th percentile patient score on the other measure (SCQ). Scores correlated negatively with age (counter to expectation). As expected, scores correlated with migraine in 2 populations, but this only explained a small part of the variance, suggesting that migraine is not the major factor underlying the spectrum of PPPD symptoms in the general population. Conclusion We found high levels of PPPD symptoms in nonclinical populations, suggesting that PPPD is a spectrum that preexists in the population, rather than only being a consequence of vestibular insult. Atypical visuo-vestibular processing predisposes some individuals to visually induced dizziness, which is then exacerbated should vestibular insult (or more generalized insult) occur

    Geologic factors in the evaluation of water pollution potential at mountain dwelling sites

    Get PDF
    December, 1973.Bibliography: pages [133]-135.In order to establish the relationship between the geologic setting and the occurrence of water pollution in mountain home developments containing individual sewage disposal systems, three areas in Colorado's Front Range were studied. Two of the areas were known to have biological contamination as confirmed by microbiological tests. Also, each area had adequate rock exposures to allow for detailed geologic study, the absence of thick soil profiles above bedrock and current development for mountain home location. In addition, each of the selected study areas differed in geologic setting, age of development and home density in the development. The extent of water pollution was established by a program of well and surface water testing for total coliform. Fecal coliform and inorganic contaminants were tested in selected wells. Detailed geologic maps were made of each area to locate features such as dikes or shear zones which might act as either barriers or conduits to ground water movement. Slope maps were prepared for the area by computer plots of digitized data of elevations taken from U.S. Geological Survey topographic maps. Determination of the water table profile and extent of alluvial fill in valley bottoms was accomplished using driller's well logs for each well in the area. In addition, soils were tested to determine their effective grain size, a joint and foliation study was conducted to determine the direction of pollutant travel should effluent enter these openings, driller's well logs were used to establish depth of soils and depth of weathering in bedrock and data from county health records were used to establish soil percolation rates. Data were compiled in the form of overlays on base maps of the areas involved. A topographic map with the geologic overlay was used in conjunction with various combinations of the field derivative overlays to indicate the pollution potential for specific areas. The overlays used in this procedure were compiled from. the following parameters: 1) slope, 2) depth of soil, 3) depth of intensely weathered bedrock, 4) local water table profile, and 5) soil percolation rates. These overlays indicated that the Glen Haven area is unsuitable for soil absorption sewage systems because of steep slopes, soil depth and depth of the water table. Most of the Tall Timbers area was indicated as unsuitable for soil absorption systems because of slope, soil depth and local geology. The Crescent Park area was categorized as safe (in part) for soil absorption systems, however, local areas within the subdivision were categorized as hazardous. From the results it was suggested that a procedure such as the one used in this study could be used for each subdivision proposed in the mountainous regions of Colorado. Thus more effective use of mountainous areas might be passable while maintaining a low probability of ground water contamination. Areas within each proposed subdivision would be classified as safe, hazardous, or unsuitable for soil absorption sewage systems. Unsuitable areas could be used as parks or greenbelts, hazardous areas would have low population densities and safe areas would be allowed to have higher population densities as long as other factors were favorable. In addition, procedures such as the one used in this investigation could be used to indicate mountain areas which should require a municipal sewage disposal system before development to ensure that the ground water system was not polluted.Supported by the Colorado Water Quality Control Commission and the United States Department of Interior, Office of Water Resources Research, no.87-194-2. (s) 14-01-001-1882

    Visual stress responses to static images are associated with symptoms of Persistent Postural Perceptual Dizziness (PPPD)

    Get PDF
    This study funded by Wellcome [104943/Z/14/Z], Wellcome and Cardiff University ISSF [097824/Z/11/Z], and Health and Care Research Wales [SCF-18-1504].BACKGROUND: Images that deviate from natural scene statistics in terms of spatial frequency and orientation content can produce visual stress (also known as visual discomfort), especially for migraine sufferers. These images appear to over-activate the visual cortex. OBJECTIVE: To connect the literature on visual discomfort with a common chronic condition presenting in neuro-otology clinics known as persistent postural perceptual dizziness (PPPD). Sufferers experience dizziness when walking through highly cluttered environments or when watching moving stimuli. This is thought to arise from maladaptive interaction between vestibular and visual signals for balance. METHODS: We measured visual discomfort to stationary images in patients with PPPD (N=30) and symptoms of PPPD in a large general population cohort (N=1858) using the Visual Vertigo Analogue Scale (VVAS) and the Situational Characteristics Questionnaire (SCQ). RESULTS: We found that patients with PPPD, and individuals in the general population with more PPPD symptoms, report heightened visual discomfort to stationary images that deviate from natural spectra (patient comparison, F (1, 1865) = 29, p < 0.001; general population correlations, VVAS, rs (1387) = 0.46, p < 0.001; SCQ, rs (1387) = 0.39, p < 0.001). These findings were not explained by co-morbid migraine. Indeed, PPPD symptoms showed a significantly stronger relationship with visual discomfort than did migraine (VVAS, zH = 8.81, p < 0.001; SCQ, zH = 6.29, p < 0.001). CONCLUSIONS: We speculate that atypical visual processing – perhaps due to a visual cortex more prone to over-activation – may predispose individuals to PPPD, possibly helping to explain why some patients with vestibular conditions develop PPPD and some do not.PostprintPeer reviewe
    • 

    corecore