235 research outputs found

    Synthesis of BaHfO3 through with reduction of KOH

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    In this work will be presented the results obtained in the synthesis and structural and morphological characterization of perovskite oxide Barium Hafnate (BaHfO3) synthesized by the hydrothermal method assisted by microwave (MAH) with two concentrations of potassium hydroxide (KOH). One with concentration of 2.4M which will be called BHO24 and another one of 3.6 M which will be called BHO36, in order to reduce the difference between the amount of reagents (in this case barium chloride and hafnium chloride- Bacl2 and HfCl4) and the amount of mineralizing agent (in this case KOH) used in synthesis through the MAH. The objective of this study is to analyze the possibility of synthesizing a perovskite oxide by MAH with the minimum amount of KOH and to analyze if there is any change in the structure or morphology of the same. To analyze the structural change, the X- ray diffraction (XRD) and to analyze the morphological change was used the characterization technique of scanning electron microscopy (SEM)

    Hearing aids do not alter cortical entrainment to speech at audible levels in mild-to-moderately hearing-impaired subjects

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    Background: Cortical entrainment to speech correlates with speech intelligibility and attention to a speech stream in noisy environments. However, there is a lack of data on whether cortical entrainment can help in evaluating hearing aid fittings for subjects with mild to moderate hearing loss. One particular problem that may arise is that hearing aids may alter the speech stimulus during (pre-)processing steps, which might alter cortical entrainment to the speech. Here, the effect of hearing aid processing on cortical entrainment to running speech in hearing impaired subjects was investigated. Methodology: Seventeen native English-speaking subjects with mild-to-moderate hearing loss participated in the study. Hearing function and hearing aid fitting were evaluated using standard clinical procedures. Participants then listened to a 25-minute audiobook under aided and unaided conditions at 70 dB A sound pressure level (SPL) in quiet conditions. EEG data were collected using a 32-channel system. Cortical entrainment to speech was evaluated using decoders reconstructing the speech envelope from the EEG data. Null decoders, obtained from EEG and the time-reversed speech envelope, were used to assess the chance level reconstructions. Entrainment in the delta- (1-4 Hz) and theta- (4-8 Hz) band, as well as wideband (1-20 Hz) EEG data was investigated. Results: Significant cortical responses could be detected for all but one subject in all three frequency bands under both aided and unaided conditions. However, no significant differences could be found between the two conditions in the number of responses detected, nor in the strength of cortical entrainment. The results show that the relatively small change in speech input provided by the hearing aid was not sufficient to elicit a detectable change in cortical entrainment. Conclusion: For subjects with mild to moderate hearing loss, cortical entrainment to speech in quiet at an audible level is not affected by hearing aids. These results clear the pathway for exploring the potential to use cortical entrainment to running speech for evaluating hearing aid fitting at lower speech intensities (which could be inaudible when unaided), or using speech in noise conditions

    Neglected zoonotic agents in cattle abortion: tackling the difficult to grow bacteria.

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    Coxiella burnetii, Chlamydia abortus and Leptospira spp. are difficult to grow bacteria that play a role in bovine abortion, but their diagnosis is hampered by their obligate intracellular lifestyle (C. burnetii, C. abortus) or their lability (Leptospira spp.). Their importance is based on the contagious spread in food-producing animals, but also as zoonotic agents. In Switzerland, first-line routine bacteriological diagnostics in cattle abortions is regulated by national law and includes only basic screening by staining for C. burnetii due to the high costs associated with extended spectrum analysis. The aim of this study was to assess the true occurrence of these zoonotic pathogens in 249 cases of bovine abortion in Switzerland by serology (ELISA for anti-C. burnetii and C. abortus antibodies and microscopic agglutination test for anti-Leptospira spp. antibodies), molecular methods (real-time PCR and sequencing of PCR products of Chlamydiales-positive cases), Stamp's modification of the Ziehl-Neelsen (mod-ZN) stain and, upon availability of material, by histology and immunohistochemistry (IHC). After seroanalysis the prevalence was 15.9% for C. burnetii, 38.5% for C. abortus and 21.4% for Leptospira spp. By real-time PCR 12.1% and 16.9% of the cases were positive for C. burnetii and Chlamydiales, respectively, but only 2.4% were positive for C. burnetii or Chlamydiales by mod-ZN stain. Sequencing of PCR products of Chlamydiales-positive cases revealed C. abortus in 10% of cases and the presence of a mix of Chlamydiales-related bacteria in 5.2% of cases. Pathogenic Leptospira spp. were detected in 5.6% of cases. Inflammatory lesions were present histologically in all available samples which were real-time PCR-positive for Chlamydiales and Leptospira spp. One of 12 real-time PCR-positive cases for C. burnetii was devoid of histological lesions. None of the pathogens could be detected by IHC. Molecular detection by real-time PCR complemented by histopathological analysis is recommended to improve definitive diagnosis of bovine abortion cases and determine a more accurate prevalence of these zoonotic pathogens

    The German Young Geoscientists Group – promoting exchange and information among the next generation of geoscientists

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    The group „Young geoscientists” of the Senate Commission for Joint Geoscientific Research (Geokommisson, www.geokommission.de) of the German Research Foundation (DFG), is dedicated towards the development of the working environment, workforce and scientific outcome of the next generation of geoscientists in Germany.Geoscientific research – basic as, well as applied – provides crucial contributions for mastering the economic, environmental and societal challenges of the near and medium-term future. Politics and society call for immediate answers, while geoscientific phenomena are complex and act on a large range of temporal and spatial scales.These demands, together with increases mobility requirements, lead to increasing pressure especially on young geoscientists. In this situation the main goals of the group “Young geoscientists” are:Promotion of networking among young geoscientistsInformation about science policy developments, funding opportunities and other relevant mattersRepresenting the interests of young scientists towards (science)-policy makersThe dynamic development of geoscientific research, particularly collaborations across traditional disciplines, as well as in increasing demands from public and policy, calls for a continuous integration of young scientists. We promote this process by organizing round-table discussions, e.g. on “Guaranteeing good scientific praxis” or on “Hot topics and research funding”, by communicating information via the internet and by identifying structural deficiencies that might hinder the advancement of the geosciences and reporting them to decision makers. In this context, we are looking for:European or international collaboratorsYoung geoscientists wishing to participate in / contribute to our activitiesSuggestions on how to improve working conditions of the young and advancing geoscientists</ul

    How does community context influence coalitions in the formation stage? a multiple case study based on the Community Coalition Action Theory

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    <p>Abstract</p> <p>Background</p> <p>Community coalitions are rooted in complex and dynamic community systems. Despite recognition that environmental factors affect coalition behavior, few studies have examined how community context impacts coalition formation. Using the Community Coalition Action theory as an organizing framework, the current study employs multiple case study methodology to examine how five domains of community context affect coalitions in the formation stage of coalition development. Domains are history of collaboration, geography, community demographics and economic conditions, community politics and history, and community norms and values.</p> <p>Methods</p> <p>Data were from 8 sites that participated in an evaluation of a healthy cities and communities initiative in California. Twenty-three focus groups were conducted with coalition members, and 76 semi-structured interviews were conducted with local coordinators and coalition leaders. Cross-site analyses were conducted to identify the ways contextual domains influenced selection of the lead agency, coalition membership, staffing and leadership, and coalition processes and structures.</p> <p>Results</p> <p>History of collaboration influenced all four coalition factors examined, from lead agency selection to coalition structure. Geography influenced coalition formation largely through membership and staffing, whereas the demographic and economic makeup of the community had an impact on coalition membership, staffing, and infrastructure for coalition processes. The influence of community politics, history, norms and values was most noticeable on coalition membership.</p> <p>Conclusions</p> <p>Findings contribute to an ecologic and theory-based understanding of the range of ways community context influences coalitions in their formative stage.</p

    Developing Theory to Guide Building Practitioners’ Capacity to Implement Evidence-Based Interventions

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    Public health and other community-based practitioners have access to a growing number of evidence-based interventions (EBIs), and yet EBIs continue to be underused. One reason for this underuse is that practitioners often lack the capacity (knowledge, skills, and motivation) to select, adapt, and implement EBIs. Training, technical assistance, and other capacity-building strategies can be effective at increasing EBI adoption and implementation. However, little is known about how to design capacity-building strategies or tailor them to differences in capacity required across varying EBIs and practice contexts. To address this need, we conducted a scoping study of frameworks and theories detailing variations in EBIs or practice contexts and how to tailor capacity-building to address those variations. Using an iterative process, we consolidated constructs and propositions across 24 frameworks and developed a beginning theory to describe salient variations in EBIs (complexity and uncertainty) and practice contexts (decision-making structure, general capacity to innovate, resource and values fit with EBI, and unity vs. polarization of stakeholder support). The theory also includes propositions for tailoring capacity-building strategies to address salient variations. To have wide-reaching and lasting impact, the dissemination of EBIs needs to be coupled with strategies that build practitioners’ capacity to adopt and implement a variety of EBIs across diverse practice contexts

    Evaluation Results of an Innovative Pilot Program to Increase Access to Fresh Fruits and Vegetables in Cobb County, GA

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    Background: This abstract describes a public health practice initiative called the Farm Fresh Market (FFM) and presented pilot evaluation results. Methods: The FFM, developed by Cobb and Douglas Public Health, the McCleskey-East Cobb Family YMCA, and Cobb2020, sold low-cost fruits and vegetables to families living in the 30168 zip code of Austell, Georgia. The evaluation focused on documenting to what extent the FFM reached its intended population and increased perceived access to fresh fruits and vegetables among customers. A convenience sample of 100 returning FFM customers completed self-administered, written intercept surveys at the end of the 2014 market season. Results: The market served customers from a range of socioeconomic backgrounds. Most customers strongly agreed that the FFM made it easier (69%) and less expensive (79%) for them to buy fresh fruits and vegetables and easier for them (63%) and their families (64%) to eat a healthy diet. Most customers reported that they ate more vegetables (65%) and fruit (55%) as a result of shopping at the FFM and reported high levels of satisfaction with all aspects of the FFM. Conclusions: The results suggest that the FFM served customers from the local area and that the FFM may have increased perceived access to healthy food options among customers. Community-level interventions to increase access to healthy foods may play an important role in chronic disease prevention

    Conformational Mechanics of Polymer Adsorption Transitions at Attractive Substrates

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    Conformational phases of a semiflexible off-lattice homopolymer model near an attractive substrate are investigated by means of multicanonical computer simulations. In our polymer-substrate model, nonbonded pairs of monomers as well as monomers and the substrate interact via attractive van der Waals forces. To characterize conformational phases of this hybrid system, we analyze thermal fluctuations of energetic and structural quantities, as well as adequate docking parameters. Introducing a solvent parameter related to the strength of the surface attraction, we construct and discuss the solubility-temperature phase diagram. Apart from the main phases of adsorbed and desorbed conformations, we identify several other phase transitions such as the freezing transition between energy-dominated crystalline low-temperature structures and globular entropy-dominated conformations.Comment: 13 pages, 15 figure

    Ferritin immobilization on patterned poly(2-hydroxyethyl methacrylate) brushes on silicon surfaces from colloid system

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    In this paper, we describe a graft polymerization/solvent immersion method for generating poly(2-hydroxyethyl methacrylate) (PHEMA) brushes in various patterns. We used a novel fabrication process, involving very-large-scale integration and oxygen plasma treatment, to generate well-defined patterns of polymerized PHEMA on patterned Si(100) surfaces. We observed brush- and mushroom-like regions for the PHEMA brushes, with various pattern resolutions, after immersing wafers presenting lines of these polymers in MeOH and n-hexane, respectively. The interaction between PHEMA and ferritin protein sheaths in MeOH and n-hexane (good and poor solvent for PHEMA, respectively) was used to capture and release ferritins from fluidic system. The “tentacles” behaver for PHEMA brushes was found through various solvents in fluidic system. Using high-resolution scanning electron microscopy, we observed patterned ferritin Fe cores on the Si surface after pyrolysis of the patterned PHEMA brushes and ferritin protein sheaths, which verify the “tentacles” behaver for PHEMA brushes

    Applying Theory to Explain the Influence of Factors External to an Organization on the Implementation of an Evidence-Based Intervention

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    Despite its widely acknowledged influence on implementation, limited research has been done on how the external environment (i.e., outer setting) determines when organizations adopt and implement new interventions. Determinant frameworks identify several outer setting-level factors such as funding streams, inter-organizational relationships, and peer pressure. However, these frameworks do not explain how or why outer-setting factors influence implementation. To advance research in this area, we argue for the importance of deriving theory-based propositions from organization theory to explain how outer setting factors influence organizations. Drawing on the work of the Organization Theory in Implementation Science (OTIS) project, we identified 20 propositions from five classic organization theories—Complexity Theory, Contingency Theory, Institutional Theory, Resource Dependence Theory, and Transaction Cost Economics. We then applied those propositions to hypothesize relationships among outer setting factors, implementation strategies, and implementation outcomes in five case studies of evidenced-based tobacco control interventions. The five case studies address the implementation of smoke-free policies, community health worker-led tobacco education and cessation programs, 5 A's (Ask, Advise, Assess, Assist, and Arrange), point-of-sale tobacco marketing policy interventions, and quitlines. The case studies illustrate how propositions may be used to guide the selection and testing of implementation strategies. Organization theories provide a menu of propositions that offer guidance for selecting and optimizing high-leverage implementation strategies that target factors at the level of outer setting. Furthermore, these propositions suggest testable hypotheses regarding the mechanisms underlying the influence of outer-setting factors on how and why organizations adopt and implement interventions
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