545 research outputs found

    Issues for computer modelling of room acoustics in non-concert hall settings

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    The basic principle of common room acoustics computer models is the energy-based geometrical room acoustics theory. The energy-based calculation relies on the averaging effect provided when there are many reflections from many different directions, which is well suited for large concert halls at medium and high frequencies. In recent years computer modelling has become an established tool in architectural acoustics design thanks to the advance in computing power and improved understanding of the modelling accuracy. However concert hall is only one of many types of built environments that require good acoustic design. Increasingly computer models are being sought for non-concert hall applications, such as in small rooms at low frequencies, flat rooms in workplace surroundings, and long enclosures such as underground stations. In these built environments the design issues are substantially difference from that of concert halls and in most cases the common room acoustics models will needed to be modified or totally re-formulated in order to deal with these new issues. This paper looks at some examples of these issues. In workplace environments we look at the issues of directional propagation and volume scattering by furniture and equipment instead of the surface scattering that is common assumed in concert hall models. In small rooms we look at the requirement of using wave models, such as boundary element models, or introducing phase information into geometrical room acoustics models to determine wave behaviours. Of particular interest is the ability of the wave models to provide phase information that is important not only for room modes but for the construction of impulse response for auralisation. Some simulated results using different modelling techniques will be presented to illustrate the problems and potential solutions

    A Single Nucleotide Change Affects Fur-Dependent Regulation of sodB in H. pylori

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    Helicobacter pylori is a significant human pathogen that has adapted to survive the many stresses found within the gastric environment. Superoxide Dismutase (SodB) is an important factor that helps H. pylori combat oxidative stress. sodB was previously shown to be repressed by the Ferric Uptake Regulator (Fur) in the absence of iron (apo-Fur regulation) [1]. Herein, we show that apo regulation is not fully conserved among all strains of H. pylori. apo-Fur dependent changes in sodB expression are not observed under iron deplete conditions in H. pylori strains G27, HPAG1, or J99. However, Fur regulation of pfr and amiE occurs as expected. Comparative analysis of the Fur coding sequence between G27 and 26695 revealed a single amino acid difference, which was not responsible for the altered sodB regulation. Comparison of the sodB promoters from G27 and 26695 also revealed a single nucleotide difference within the predicted Fur binding site. Alteration of this nucleotide in G27 to that of 26695 restored apo-Fur dependent sodB regulation, indicating that a single base difference is at least partially responsible for the difference in sodB regulation observed among these H. pylori strains. Fur binding studies revealed that alteration of this single nucleotide in G27 increased the affinity of Fur for the sodB promoter. Additionally, the single base change in G27 enabled the sodB promoter to bind to apo-Fur with affinities similar to the 26695 sodB promoter. Taken together these data indicate that this nucleotide residue is important for direct apo-Fur binding to the sodB promoter

    Multilayer Regulation of Neisseria meningitidis NHBA at Physiologically Relevant Temperatures

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    Neisseria meningitidis colonizes the nasopharynx of humans, and pathogenic strains can disseminate into the bloodstream, causing septicemia and meningitis. NHBA is a surface-exposed lipoprotein expressed by all N. meningitidis strains in different isoforms. Diverse roles have been reported for NHBA in heparin-mediated serum resistance, biofilm formation, and adherence to host tissues. We determined that temperature controls the expression of NHBA in all strains tested, with increased levels at 30–32◦C compared to 37◦C. Higher NHBA expression at lower temperatures was measurable both at mRNA and protein levels, resulting in higher surface exposure. Detailed molecular analysis indicated that multiple molecular mechanisms are responsible for the thermoregulated NHBA expression. The comparison of mRNA steady-state levels and half-lives at 30◦C and 37◦C demonstrated an increased mRNA stability/translatability at lower temperatures. Protein stability was also impacted, resulting in higher NHBA stability at lower temperatures. Ultimately, increased NHBA expression resulted in higher susceptibility to complement-mediated killing. We propose that NHBA regulation in response to temperature downshift might be physiologically relevant during transmission and the initial step(s) of interaction within the host nasopharynx. Together these data describe the importance of NHBA both as a virulence factor and as a vaccine antigen during neisserial colonization and invasion

    Genetic variation exists for telomeric array organization within and among the genomes of normal, immortalized, and transformed chicken systems

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    This study investigated telomeric array organization of diverse chicken genotypes utilizing in vivo and in vitro cells having phenotypes with different proliferation potencies. Our experimental objective was to characterize the extent and nature of array variation present to explore the hypothesis that mega-telomeres are a universal and fixed feature of chicken genotypes. Four different genotypes were studied including normal (UCD 001, USDA-ADOL Line 0), immortalized (DF-1), and transformed (DT40) cells. Both cytogenetic and molecular approaches were utilized to develop an integrated view of telomeric array organization. It was determined that significant variation exists within and among chicken genotypes for chromosome-specific telomeric array organization and total genomic-telomeric sequence content. Although there was variation for mega-telomere number and distribution, two mega-telomere loci were in common among chicken genetic lines (GGA 9 and GGA W). The DF-1 cell line was discovered to maintain a complex derivative karyotype involving chromosome fusions in the homozygous and heterozygous condition. Also, the DF-1 cell line was found to contain the greatest amount of telomeric sequence per genome (17%) as compared to UCD 001 (5%) and DT40 (1.2%). The chicken is an excellent model for studying unique and universal features of vertebrate telomere biology, and characterization of the telomere length variation among genotypes will be useful in the exploration of mechanisms controlling telomere length maintenance in different cell types having unique phenotypes

    Practicing physiotherapy in Danish private practice: an ethical perspective.

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    Despite an increasingly growth of professional guidelines, textbooks and research about ethics in health care, awareness about ethics in Danish physiotherapy private practice seen vague. This article explores how physiotherapists in Danish private practice, from an ethical perspective, perceive to practice physiotherapy. The empirical data consists of interviews with twenty-one physiotherapists. The interviews are analysed from a hermeneutic approach, inspired by Ricoeur's textual interpretation of distanciation. The analysis follows three phases: naïve reading, structural analysis and comprehensive analysis. Four main themes are constructed: Beneficence as the driving force; Disciplining the patient through the course of physiotherapy; Balancing between being a trustworthy professional and a businessperson; The dream of a code of practice. Private practice physiotherapy is embedded in a structural frame directed by both political and economical conditions that shape the conditions for practicing physiotherapy. It means that beneficence in practice is a balance between the patient, the physiotherapists themselves and the business. Beneficence towards the patient is expressed as an implicit demand. Physiotherapeutic practice is expressed as being an integration of professionalism and personality which implies that the physiotherapists also have to benefit themselves. Private practice seems to be driven by a paternalistic approach towards the patient, where disciplining the patient is a crucial element of practice, in order to optimise profit. Physiotherapists wish for a more beneficent practice in the future by aiming at bridging 'to be' and 'ought to be'

    Population overlap and habitat segregation in wintering Black-tailed Godwits Limosa limosa

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    Distinct breeding populations of migratory species may overlap both spatially and temporally, but differ in patterns of habitat use. This has important implications for population monitoring and conservation. To quantify the extent to which two distinct breeding populations of a migratory shorebird, the Black-tailed Godwit Limosa limosa, overlap spatially, temporally and in their use of different habitats during winter. We use mid-winter counts between 1990 and 2001 to identify the most important sites in Iberia for Black-tailed Godwits. Monthly surveys of estuarine mudflats and rice-fields at one major site, the Tejo estuary in Portugal in 2005-2007, together with detailed tracking of colour-ringed individuals, are used to explore patterns of habitat use and segregation of the Icelandic subspecies L. l. islandica and the nominate continental subspecies L. l. limosa. In the period 1990-2001, over 66 000 Black-tailed Godwits were counted on average in Iberia during mid-winter (January), of which 80% occurred at just four sites: Tejo and Sado lower basins in Portugal, and Coto Dontildeana and Ebro Delta in Spain. Icelandic Black-tailed Godwits are present throughout the winter and forage primarily in estuarine habitats. Continental Black-tailed Godwits are present from December to March and primarily use rice-fields. Iberia supports about 30% of the Icelandic population in winter and most of the continental population during spring passage. While the Icelandic population is currently increasing, the continental population is declining rapidly. Although the estuarine habitats used by Icelandic godwits are largely protected as Natura 2000 sites, the habitat segregation means that conservation actions for the decreasing numbers of continental godwits should focus on protection of rice-fields and re-establishment of freshwater wetlands

    Physical Activity Level and Physical Functionality in Nonagenarians Compared to Individuals Aged 60–74 Years

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    Background: Functional dependence and the risks of disability increase with age. The loss of independence is thought to be partially due to a decrease in physical activity. However, in populations, accurate measurement of physical activity is challenging and may not provide information on functional impairment. Methods: This study therefore assessed physical functionality and physical activity level in a group of nonagenarians (11 men/11 women; 93+/-1 years, 66.6+/-2.4 kg, body mass index [BMI]=24+/-1 kg/m2) and a group of participants aged 60-74 years (17 men/15 women; 70+/-1 years, 83.3+/-3.0 kg, BMI=29+/-1 kg/m2) from the Louisiana Healthy Aging Study. Physical activity level was calculated from total energy expenditure (TEE) and resting metabolic rate (RMR). Physical functionality was assessed using the Reduced Continuous Scale Physical Functional Performance Test (CS-PFP10). Results: Nonagenarians had lower absolute (p Conclusions: When compared to individuals aged 60-74 years, 73% of the reduction in TEE in nonagenarians can be attributed to a reduction in physical activity level, the remaining being accounted for by a reduction in RMR. The reduced physical activity in nonagenarians is associated with less physical functionality. This study provides the first objective comparison of physical functionality and actual levels of physical activity in older individuals

    Moraxella catarrhalis evades neutrophil oxidative stress responses providing a safer niche for nontypeable Haemophilus influenzae

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    Moraxella catarrhalis and nontypeable Haemophilus influenzae (NTHi) are pathogenic bacteria frequently associated with exacerbation of chronic obstructive pulmonary disease (COPD), whose hallmark is inflammatory oxidative stress. Neutrophils produce reactive oxygen species (ROS) which can boost antimicrobial response by promoting neutrophil extracellular traps (NET) and autophagy. Here, we showed that M. catarrhalis induces less ROS and NET production in differentiated HL-60 cells compared to NTHi. It is also able to actively interfere with these responses in chemically activated cells in a phagocytosis and opsonin-independent and contact-dependent manner, possibly by engaging host immunosuppressive receptors. M. catarrhalis subverts the autophagic pathway of the phagocytic cells and survives intracellularly. It also promotes the survival of NTHi which is otherwise susceptible to the host antimicrobial arsenal. In-depth understanding of the immune evasion strategies exploited by these two human pathogens could suggest medical interventions to tackle COPD and potentially other diseases in which they co-exist

    Health Impact Assessment in New South Wales & Health in All Policies in South Australia: differences, similarities and connections

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: Policy decisions made within all sectors have the potential to influence population health and equity. Recognition of this provides impetus for the health sector to engage with other sectors to facilitate the development of policies that recognise, and aim to improve, population outcomes. This paper compares the approaches implemented to facilitate such engagement in two Australian jurisdictions. These are Health Impact Assessment (HIA) in New South Wales (NSW) and Health in All Policies (HiAP) in South Australia (SA). Methods: The comparisons presented in this paper emerged through collaborative activities between stakeholders in both jurisdictions, including critical reflection on HIA and HiAP practice, joint participation in a workshop, and the preparation of a discussion paper written to inform a conference plenary session. The plenary provided an opportunity for the incorporation of additional insights from policy practitioners and academics. Results: Comparison of the approaches indicates that their overall intent is similar. Differences exist, however, in the underpinning principles, technical processes and tactical strategies applied. These differences appear to stem mainly from the organisational positioning of the work in each state and the extent to which each approach is linked to government systems. Conclusions: The alignment of the HiAP approach with the systems of the SA Government increases the likelihood of influence within the policy cycle. However, the political priorities and sensitivities of the SA Government limit the scope of HiAP work. The implementation of the HIA approach from outside government in NSW means greater freedom to collaborate with a range of partners and to assess policy issues in any area, regardless of government priorities. However, the comparative distance of HIA from NSW Government systems may reduce the potential for impact on government policy. The diversity in the technical and tactical strategies that are applied within each approach provides insight into how the approaches have been tailored to suit the particular contexts in which they have been implemented. Keywords: Health in all policies, Health impact assessment, Healthy public polic
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