415 research outputs found

    Superfluid Density and Field-Induced Magnetism in Ba(Fe1-xCox)2As2 and Sr(Fe1-xCox)2As2 Measured with Muon Spin Relaxation

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    We report muon spin rotation (μ\muSR) measurements of single crystal Ba(Fe1x_{1-x}Cox_x)2_2As2_2 and Sr(Fe1x_{1-x}Cox_x)2_2As2_2. From measurements of the magnetic field penetration depth λ\lambda we find that for optimally- and over-doped samples, 1/λ(T0)21/\lambda(T\to 0)^2 varies monotonically with the superconducting transition temperature TC_{\rm C}. Within the superconducting state we observe a positive shift in the muon precession signal, likely indicating that the applied field induces an internal magnetic field. The size of the induced field decreases with increasing doping but is present for all Co concentrations studied.Comment: 7 pages, accepted for publication in Phys. Rev.

    Platelet and Neutrophil Responses to Gram Positive Pathogens in Patients with Bacteremic Infection

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    BACKGROUND: Many Gram-positive pathogens aggregate and activate platelets in vitro and this has been proposed to contribute to virulence. Platelets can also form complexes with neutrophils but little is however known about platelet and platelet-neutrophil responses in bacterial infection. METHODOLOGY/PRINCIPAL FINDINGS: We added isolates of Gram-positive bacteria from 38 patients with a bacteremic infection to blood drawn from the same patient. Aggregometry and flow cytometry were used to assess platelet aggregation and to quantify activation of platelets, neutrophils, and platelet-neutrophils complexes (PNCs) induced by the bacteria. Fifteen healthy persons served as controls. Most isolates of Staphylococcus aureus, beta hemolytic streptococci, and Enterococcus faecalis induced aggregation of platelets from their respective hosts, whereas pneumococci failed to do so. S. aureus isolates induced platelet aggregation more rapidly in patients than in controls, whereas platelet activation by S. aureus was lower in patients than in controls. PNCs were more abundant in baseline samples from patients than in healthy controls and most bacterial isolates induced additional PNC formation and neutrophil activation. CONCLUSION/SIGNIFICANCE: We have demonstrated for the first time that bacteria isolated from patients with Gram-positive bacteremia can induce platelet activation and aggregation, PNC formation, and neutrophil activation in the same infected host. This underlines the significance of these interactions during infection, which could be a target for future therapies in sepsis

    Alert but less alarmed: a pooled analysis of terrorism threat perception in Australia

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    <p>Abstract</p> <p>Background</p> <p>Previous Australian research has highlighted disparities in community perceptions of the threat posed by terrorism. A study with a large sample size is needed to examine reported concerns and anticipated responses of community sub-groups and to determine their consistency with existing Australian and international findings.</p> <p>Methods</p> <p>Representative samples of New South Wales (NSW) adults completed terrorism perception questions as part of computer assisted telephone interviews (CATI) in 2007 (N = 2081) and 2010 (N = 2038). Responses were weighted against the NSW population. Data sets from the two surveys were pooled and multivariate multilevel analyses conducted to identify health and socio-demographic factors associated with higher perceived risk of terrorism and evacuation response intentions, and to examine changes over time.</p> <p>Results</p> <p>In comparison with 2007, Australians in 2010 were significantly more likely to believe that a terrorist attack would occur in Australia (Adjusted Odd Ratios (AOR) = 1.24, 95%CI:1.06-1.45) but felt less concerned that they would be directly affected by such an incident (AOR = 0.65, 95%CI:0.55-0.75). Higher perceived risk of terrorism and related changes in living were associated with middle age, female gender, lower education and higher reported psychological distress. Australians of migrant background reported significantly lower likelihood of terrorism (AOR = 0.52, 95%CI:0.39-0.70) but significantly higher concern that they would be personally affected by such an incident (AOR = 1.57, 95%CI:1.21-2.04) and having made changes in the way they live due to this threat (AOR = 2.47, 95%CI:1.88-3.25). Willingness to evacuate homes and public places in response to potential incidents increased significantly between 2007 and 2010 (AOR = 1.53, 95%CI:1.33-1.76).</p> <p>Conclusion</p> <p>While an increased proportion of Australians believe that the national threat of terrorism remains high, concern about being personally affected has moderated and may reflect habituation to this threat. Key sub-groups remain disproportionately concerned, notably those with lower education and migrant groups. The dissonance observed in findings relating to Australians of migrant background appears to reflect wider socio-cultural concerns associated with this issue. Disparities in community concerns regarding terrorism-related threat require active policy consideration and specific initiatives to reduce the vulnerabilities of known risk groups, particularly in the aftermath of future incidents.</p

    The materiality of the intangible: Literary metaphor in multimodal texts

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    Based on a larger practice-based research project in digital writing, this article examines how the materiality of digital media contributes to a layered metaphor that delivers meaning, reflects on the cognitive processes (the writer’s and the reader’s) of navigation and generates a dynamic narrative structure through multimodality, unnatural narration and user interaction. Many writers and artists engage with their chosen medium through an instinctive understanding of the materials at hand, gained through experience; the explicit study of a medium’s materiality is not always required for artistic success, however, that may be judged. This article offers insights into the creative process of creating digital, multimodal fiction, based on a practice-based research project designed to explore the effects of digital media on author and text, and argues that digital media have a significant effect on the outcome of the artefact itself. Awareness of these effects, their variations according to hardware and software, and the affordances of these various materials offer the digital writer greater insight and capability to craft his/her texts for the desired metaphorical meaning

    Digital transformations and the archival nature of surrogates

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    Large-scale digitization is generating extraordinary collections of visual and textual surrogates, potentially endowed with transcendent long-term cultural and research values. Understanding the nature of digital surrogacy is a substantial intellectual opportunity for archival science and the digital humanities, because of the increasing independence of surrogate collections from their archival sources. The paper presents an argument that one of the most significant requirements for the long-term access to collections of digital surrogates is to treat digital surrogates as archival records that embody traces of their fluid lifecycles and therefore are worthy of management and preservation as archives. It advances a theory of the archival nature of surrogacy founded on longstanding notions of archival quality, the traces of their source and the conditions of their creation, and the functional ‘‘work of the archive.’’ The paper presents evidence supporting a ‘‘secondary provenance’’ derived from re-digitization, re-ingestion of multiple versions, and de facto replacement of the original sources. The design of the underlying research that motivates the paper and summary findings are reported separately. The research has been supported generously by the US Institute of Museum and Library Services.Institute for Museum and Library ServicesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111825/1/J26 Conway Digital Transformations 2014-pers.pdfDescription of J26 Conway Digital Transformations 2014-pers.pdf : Main articl

    COX2 genetic variation, NSAIDs, and advanced prostate cancer risk

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    Collective evidence suggests that cyclooxygenase 2 (COX2) plays a role in prostate cancer risk. Cyclooxygenase 2 is the major enzyme that converts arachidonic acid to prostaglandins, which are potent mediators of inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the enzymatic activity of COX2 and long-term use of NSAIDs appears to modestly lower the risk of prostate cancer. We investigated whether common genetic variation in COX2 influences the risk of advanced prostate cancer. Nine single-nucleotide polymorphisms (SNPs) in COX2 were genotyped among 1012 men in our case–control study of advanced prostate cancer. Gene–environment interactions between COX2 polymorphisms and NSAID use were also evaluated. Information on NSAID use was obtained by questionnaire. Three SNPs demonstrated nominally statistically significant associations with prostate cancer risk, with the most compelling polymorphism (rs2745557) associated with a lower risk of disease (odds ratio (OR) GC vs GG=0.64; 95% confidence interval (CI): 0.49–0.84; P=0.002). We estimated through permutation analysis that a similarly strong result would occur by chance 2.7% of the time. Nonsteroidal anti-inflammatory drug use was associated with a lower risk of disease in comparison to no use (OR=0.67; 95% CI: 0.52–0.87). No significant statistical interaction between NSAID use and rs2745557 was observed (P=0.12). Our findings suggest that variation in COX2 is associated with prostate cancer risk

    Terrorism in Australia: factors associated with perceived threat and incident-critical behaviours

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    <p>Abstract</p> <p>Background</p> <p>To help improve incident preparedness this study assessed socio-demographic and socio-economic predictors of perceived risk of terrorism within Australia and willingness to comply with public safety directives during such incidents.</p> <p>Methods</p> <p>The terrorism perception question module was incorporated into the New South Wales Population Health Survey and was completed by a representative sample of 2,081 respondents in early 2007. Responses were weighted against the New South Wales population.</p> <p>Results</p> <p>Multivariate analyses indicated that those with no formal educational qualifications were significantly more likely (OR = 2.10, 95%CI:1.32–3.35, p < 0.001) to think that a terrorist attack is very or extremely likely to occur in Australia and also more likely (OR = 3.62, 95%CI:2.25–5.83, p < 0.001) to be very or extremely concerned that they or a family member would be directly affected, compared to those with a university-level qualification. Speaking a language other than English at home predicted high concern (very/extremely) that self or family would be directly affected (OR = 3.02, 95%CI:2.02–4.53, p < 0.001) and was the strongest predictor of having made associated changes in living (OR = 3.27, 95%CI:2.17–4.93, p < 0.001). Being female predicted willingness to evacuate from public facilities. Speaking a language other than English at home predicted low willingness to evacuate.</p> <p>Conclusion</p> <p>Low education level is a risk factor for high terrorism risk perception and concerns regarding potential impacts. The pattern of concern and response among those of migrant background may reflect secondary social impacts associated with heightened community threat, rather than the direct threat of terrorism itself. These findings highlight the need for terrorism risk communication and related strategies to address the specific concerns of these sub-groups as a critical underpinning of population-level preparedness.</p

    Barriers to disseminating brief CBT for voices from a lived experience and clinician perspective

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    Access to psychological therapies continues to be poor for people experiencing psychosis. To address this problem, researchers are developing brief interventions that address the specific symptoms associated with psychosis, i.e., hearing voices. As part of the development work for a brief Cognitive Behaviour Therapy (CBT) intervention for voices we collected qualitative data from people who hear voices (study 1) and clinicians (study 2) on the potential barriers and facilitators to implementation and engagement. Thematic analysis of the responses from both groups revealed a number of anticipated barriers to implementation and engagement. Both groups believed the presenting problem (voices and psychosis symptoms) may impede engagement. Furthermore clinicians identified a lack of resources to be a barrier to implementation. The only facilitator to engagement was reported by people who hear voices who believed a compassionate, experienced and trustworthy therapist would promote engagement. The results are discussed in relation to how these barriers could be addressed in the context of a brief intervention using CBT techniques

    Chemical Basis of Prey Recognition in Thamnophiine Snakes: The Unexpected New Roles of Parvalbumins

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    Detecting and locating prey are key to predatory success within trophic chains. Predators use various signals through specialized visual, olfactory, auditory or tactile sensory systems to pinpoint their prey. Snakes chemically sense their prey through a highly developed auxiliary olfactory sense organ, the vomeronasal organ (VNO). In natricine snakes that are able to feed on land and water, the VNO plays a critical role in predatory behavior by detecting cues, known as vomodors, which are produced by their potential prey. However, the chemical nature of these cues remains unclear. Recently, we demonstrated that specific proteins–parvalbumins–present in the cutaneous mucus of the common frog (Rana temporaria) may be natural chemoattractive proteins for these snakes. Here, we show that parvalbumins and parvalbumin-like proteins, which are mainly intracellular, are physiologically present in the epidermal mucous cells and mucus of several frog and fish genera from both fresh and salt water. These proteins are located in many tissues and function as Ca2+ buffers. In addition, we clarified the intrinsic role of parvalbumins present in the cutaneous mucus of amphibians and fishes. We demonstrate that these Ca2+-binding proteins participate in innate bacterial defense mechanisms by means of calcium chelation. We show that these parvalbumins are chemoattractive for three different thamnophiine snakes, suggesting that these chemicals play a key role in their prey-recognition mechanism. Therefore, we suggest that recognition of parvalbumin-like proteins or other calcium-binding proteins by the VNO could be a generalized prey-recognition process in snakes. Detecting innate prey defense mechanism compounds may have driven the evolution of this predator-prey interaction
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