89 research outputs found

    Wilhelm Ostwald

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    This poster for the Natural Sciences Poster Session at Parkland College features chemist Wilhelm Ostwald who discovered the law of dilution in 1988, which is the application of the law of mass action to weak electrolytes in solution. He also developed a process of catalytic oxidation of ammonia to nitric acid and introduced the word mole

    Determining the Water Baseline for the Ann Arbor 2030 District

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    The effects of global warming are becoming more apparent in major cities and are requiring adaptive and mitigative efforts. Many cities across the country are working towards becoming more efficient and adapting for the future changing environment. There are currently no established national benchmark averages for water use consumption in buildings. This leaves local governments and districts to create their own methods for establishing a water baseline. One metric for setting a water baseline is water use intensity (WUI), which is calculated by dividing water used in a building by building floor area. Water use intensity is a useful metric for municipalities because they can be used to set water use reduction goals and assess progress towards them in the future. As local governments and municipalities are determining the best way to establish their water baselines, this work examines the Ann Arbor 2030 District and the process used to gather the data necessary for establishing a water baseline. The Ann Arbor 2030 District is one of 22 Districts currently operating across North America. The 2030 Districts are private/public partnerships formed to meet energy, water, and vehicle emissions reduction targets for existing buildings and new construction projects within their boundaries. The Districts were formed to create a network of high-performance districts that work together to create and improve infrastructure to mitigate and adapt to climate change. The goals of the 2030 Districts are to reduce building and infrastructure energy use, water use, and transportation carbon dioxide emissions by 50% from a baseline by 2030. The majority of 2030 Districts use a water benchmarking method very similar to that adopted by the Ann Arbor 2030 District. It is important to examine other water benchmarking methods to understand why the WUI metric was chosen for local water benchmarking. Understanding the method that the Ann Arbor 2030 district used will help other district and city managers gain a better understanding of the options available, and the potential challenges, to calculate the water baseline, specifically as WUI, of commercial buildings within their cities.Master of ScienceSchool for Environment and SustainabilityUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/167153/1/Johnson-Lane_Kori_practicum.pd

    Genetic comparison of water molds from embryos of amphibians Rana cascadae, Bufo boreas and Pseudacris regilla

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    Water molds that cause the disease saprolegniasis have been implicated in widespread mortality of amphibian embryos. However, because of the limitations of traditional identification methods, water mold species involved in die-offs or utilized in ecological studies often remain unidentified or identified only as Saprolegnia ferax. Furthermore, water mold taxonomy requires revision, so very distinct organisms may all be called S. ferax. Recent DNA-based studies indicate that the diversity of water molds infecting amphibian embryos is significantly higher than what was previously known, but these studies rely on culture methods, which may be biased towards taxa that grow best under laboratory conditions. In this study, total embryo-associated DNA was extracted from 3 amphibian species in a pond in central Washington, USA. The internal transcribed spacer (ITS) region of DNA was amplified with primers capable of amplifying a broad array of eukaryotic microorgansisms, and was used to construct clone libraries. Individual clones were sequenced and relationships among newly recovered sequences and previously studied taxa were analyzed using phylogenetics. These methods recovered several new taxa in association with amphibian embryos. Samples grouped into 11 distinct phylotypes with ITS sequence differences ranging from 4 to 28%. The water mold communities recovered differed among Rana cascadae, Bufo boreas, and Pseudacris regilla egg masses. Furthermore, the diversity of water molds increased as egg masses aged, and members comprising this diversity changed over time

    Independent distractor frequency and age-of-acquisition effects in picture-word interference: fMRI evidence for post-lexical and lexical accounts according to distractor type

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    In two fMRI experiments, participants named pictures with superimposed distractors that were high or low in frequency or varied in terms of age of acquisition. Pictures superimposed with low-frequency words were named more slowly than those superimposed with high-frequency words, and late-acquired words interfered with picture naming to a greater extent than early-acquired words. The distractor frequency effect (Experiment 1) was associated with increased activity in left premotor and posterior superior temporal cortices, consistent with the operation of an articulatory response buffer and verbal self-monitoring system. Conversely, the distractor age-of-acquisition effect (Experiment 2) was associated with increased activity in the left middle and posterior middle temporal cortex, consistent with the operation of lexical level processes such as lemma and phonological word form retrieval. The spatially dissociated patterns of activity across the two experiments indicate that distractor effects in picture–word interference may occur at lexical or postlexical levels of processing in speech production

    An fMRI investigation of the effects of attempted naming on word retrieval in aphasia

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    In healthy controls, picture naming performance can be facilitated by a single prior exposure to the same picture ("priming"). This priming phenomenon is utilized in the treatment of aphasia, which often includes repeated picture naming as part of a therapeutic task. The current study sought to determine whether single and/or multiple exposures facilitate subsequent naming in aphasia and whether such facilitatory effects act through normal priming mechanisms. A functional magnetic resonance imaging paradigm was employed to explore the beneficial effects of attempted naming in two individuals with aphasia and a control group. The timing and number of prior exposures was manipulated, with investigation of both short-term effects (single prior exposure over a period of minutes) and long-term effects (multiple presentations over a period of days). Following attempted naming, both short-term and long-term facilitated items showed improvement for controls, while only the long-term condition showed benefits at a behavioral level for the participants with aphasia. At a neural level, effects of long-term facilitation were noted in the left precuneus for one participant with aphasia, a result also identified for the equivalent contrast in controls. It appears that multiple attempts are required to improve naming performance in the presence of anomia and that for some individuals with aphasia the source of facilitation may be similar to unimpaired mechanisms engaged outside the language network

    Communication changes following non-glottic head and neck cancer management: The perspectives of survivors and carers

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    Purpose. Head and neck cancer (HNC) survivors may experience functional changes to their voice, speech and hearing following curative chemoradiotherapy. However, few studies have explored the impact of living with such changes from the perspective of the HNC survivor and their carer. The current study employed a person-centred approach to explore the lived experience of communication changes following chemoradiotherapy treatment for HNC from the perspective of survivors and carers. Method. Participants included 14 survivors with non-glottic HNC and nine carers. All participants took part in in-depth interviews where they were encouraged to describe their experiences of living with and adjusting to communication changes following treatment. Interviews were analysed as a single data set. Result. Four themes emerged including: (1) impairments in communication sub-systems; (2) the challenges of communicating in everyday life; (3) broad ranging effects of communication changes; and (4) adaptations as a result of communication changes. Conclusion. These data confirm that communication changes following chemoradiotherapy have potentially negative psychosocial impacts on both the HNC survivor and their carer. Clinicians should consider the impact of communication changes on the life of the HNC survivor and their carer and provide adequate and timely education and management to address the needs of this population

    Gene network effects on brain microstructure and intellectual performance identified in 472 twins

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    A major challenge in neuroscience is finding which genes affect brain integrity, connectivity, and intellectual function. Discovering influential genes holds vast promise for neuroscience, but typical genome-wide searches assess approximately one million genetic variants one-by-one, leading to intractable false positive rates, even with vast samples of subjects. Even more intractable is the question of which genes interact and how they work together to affect brain connectivity. Here, we report a novel approach that discovers which genes contribute to brain wiring and fiber integrity at all pairs of points in a brain scan. We studied genetic correlations between thousands of points in human brain images from 472 twins and their nontwin siblings (mean age: 23.7 ± 2.1 SD years; 193 male/279 female). We combined clustering with genome-wide scanning to find brain systems with common genetic determination. We then filtered the image in a new way to boost power to find causal genes. Using network analysis, we found a network of genes that affect brain wiring in healthy young adults. Our new strategy makes it computationally more tractable to discover genes that affect brain integrity. The gene network showed small-world and scale-free topologies, suggesting efficiency in genetic interactions and resilience to network disruption. Genetic variants at hubs of the network influence intellectual performance by modulating associations between performance intelligence quotient and the integrity of major white matter tracts, such as the callosal genu and splenium, cingulum, optic radiations, and the superior longitudinal fasciculus

    Changes in catastrophizing and kinesiophobia are predictive of changes in disability and pain after treatment in patients with anterior knee pain

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    Purpose. The purpose of the study was to investigate if changes in psychological variables are related to the outcome in pain and disability in patients with chronic anterior knee pain. Methods. A longitudinal observational study on 47 patients with chronic anterior knee pain was performed in a secondary healthcare setting. Pain was measured with the visual analogue scale and disability with the Lysholm scale. The psychological variables, such as anxiety, depression, pain coping strategies, catastrophizing and fear to movement beliefs, were studied by using self-administered questionnaires. Results. Among the pain coping strategies, only the catastrophizing subscale showed a significant reduction. Similarly, anxiety, depression and kinesiophobia were significantly reduced after treatment. Those patients who decreased the catastrophizing, kinesiophobia, anxiety and depression showed a greater improvement in pain and disability after a purely biomedical treatment. A multiple regression analysis revealed that changes in catastrophizing predicted the amount of improvement in pain severity and that changes in both catastrophizing and anxiety predicted changes in disability after treatment. Conclusion. What has been found suggests that clinical improvement in pain and disability is associated with a reduction in catastrophizing and kinesiophobia. Therefore, co-interventions to reduce catastrophizing thinking and kinesiophobia may enhance the results. Level of evidence. Prospective Cohort Study, Level I for prognosis
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