2,845 research outputs found

    Topological freeness for CC^*-correspondences

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    We study conditions that ensure uniqueness theorems of Cuntz-Krieger type for relative Cuntz-Pimsner algebras O(J,X)\mathcal{O}(J,X) associated to a CC^*-correspondence XX over a CC^*-algebra AA. We give general sufficient conditions phrased in terms of a multivalued map X^\widehat{X} acting on the spectrum A^\widehat{A} of AA. When X(J)X(J) is of Type I we construct a directed graph dual to XX and prove a uniqueness theorem using this graph. When X(J)X(J) is liminal, we show that topological freeness of this graph is equivalent to the uniqueness property for O(J,X)\mathcal{O}(J,X), as well as to an algebraic condition, which we call JJ-acyclicity of XX. As an application we improve the Fowler-Raeburn uniqueness theorem for the Toeplitz algebra TX\mathcal{T}_X. We give new simplicity criteria for OX\mathcal{O}_X. We generalize and enhance uniqueness results for relative quiver CC^*-algebras of Muhly and Tomforde. We also discuss applications to crossed products by endomorphisms.Comment: We have updated the list of references, fixed some typos and made other minor improvements. This is the version that will be publishe

    Dankort payments as a timely indicator of retail sales in Denmark

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    The paper examines whether electronic payments by card (Dankort) provides a useful indicator for retail sales in Denmark. Dankort transactions data is available about one week after the reference month, while the retail sales index is only published about three weeks later. We add to previous work by setting up a model for the seasonally adjusted volume index for retail sales. The extensions considered are meant to further enhance the usefulness of the nowcasting model for conjunctural analysis. The out-of-sample forecasting ability of the model compares favourably with a benchmark autoregression

    Cartan subalgebras in C*-algebras of Hausdorff etale groupoids

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    The reduced CC^*-algebra of the interior of the isotropy in any Hausdorff \'etale groupoid GG embeds as a CC^*-subalgebra MM of the reduced CC^*-algebra of GG. We prove that the set of pure states of MM with unique extension is dense, and deduce that any representation of the reduced CC^*-algebra of GG that is injective on MM is faithful. We prove that there is a conditional expectation from the reduced CC^*-algebra of GG onto MM if and only if the interior of the isotropy in GG is closed. Using this, we prove that when the interior of the isotropy is abelian and closed, MM is a Cartan subalgebra. We prove that for a large class of groupoids GG with abelian isotropy---including all Deaconu--Renault groupoids associated to discrete abelian groups---MM is a maximal abelian subalgebra. In the specific case of kk-graph groupoids, we deduce that MM is always maximal abelian, but show by example that it is not always Cartan.Comment: 14 pages. v2: Theorem 3.1 in v1 incorrect (thanks to A. Kumjain for pointing out the error); v2 shows there is a conditional expectation onto MM iff the interior of the isotropy is closed. v3: Material (including some theorem statements) rearranged and shortened. Lemma~3.5 of v2 removed. This version published in Integral Equations and Operator Theor

    Assessment of problematic severe asthma in children

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    Assessment of problematic severe asthma in children should be performed in a stepwise manner to ensure an optimal approach. A four-step assessment scheme is proposed. First, a full diagnostic work-up is performed to exclude other diseases which mimic asthma. Secondly, a multi-disciplinary assessment is performed to identify issues that may need attention, including comorbidities. Thirdly, the pattern of inflammation is assessed, and finally steroid responsiveness is documented. Based upon these four steps an optimal individualised treatment plan is developed. In this article the many gaps in our current knowledge in all these steps are highlighted, and recommendations for current clinical practice and future research are made. The lack of good data and the heterogeneity of problematic severe asthma still limit our ability to optimise the management on an individual basis in this small, but challenging group of patients

    Distribution of ferns in the Maple-Beech Forest at the Cedar-Sauk Field Station

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    This report is another in a series of plant studies under investigation at the UWM Cedar-Sauk Field Station. Most of the previous studies were concerned with seed plants and only limited attention was given to the fern flora. In this study, carried out chiefly in the summer of 1970, the fern species were evaluated to determine their importance, distribution and ecological relationships in the maple-beech forest

    Project MOSI: rationale and pilot-study results of an initiative to help protect zoo animals from mosquito-transmitted pathogens and contribute data on mosquito spatio–temporal distribution change

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    Mosquito-borne pathogens pose major threats to both wildlife and human health and, largely as a result of unintentional human-aided dispersal of their vector species, their cumulative threat is on the rise. Anthropogenic climate change is expected to be an increasingly significant driver of mosquito dispersal and associated disease spread. The potential health implications of changes in the spatio-temporal distribution of mosquitoes highlight the importance of ongoing surveillance and, where necessary, vector control and other health-management measures. The World Association of Zoos and Aquariums initiative, Project MOSI, was established to help protect vulnerable wildlife species in zoological facilities from mosquito-transmitted pathogens by establishing a zoo-based network of fixed mosquito monitoring sites to assist wildlife health management and contribute data on mosquito spatio-temporal distribution changes. A pilot study for Project MOSI is described here, including project rationale and results that confirm the feasibility of conducting basic standardized year-round mosquito trapping and monitoring in a zoo environment

    Early-stage breast cancer is not associated with the risk of marital dissolution in a large prospective study of women

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    Background: As breast cancer and its treatment are likely to interfere with traditional expectations of womanhood, it may affect marital stability. Methods: The risk of marital dissolution was analysed with respect to diagnosis of early-stage (T1-4N0-3M0) breast cancer in a cohort of 134 435 married Finnish women followed for a median of 17.0 married years. Age, socioeconomic status, education, number of children, duration of marriage and earlier marriages were taken into account and the effects of surgery, chemotherapy, radiotherapy and endocrine therapy were analysed separately. Results: Women with a diagnosis of early-stage breast cancer did not show increase in marital dissolution (hazard ratio -0.96, 95% confidence interval = 0.79-1.17). Neither the type of surgical procedure nor any of the oncologic treatments was associated with an increase in the risk of divorce. Conclusions: Any evidence of excess risk of marital breakdown after the diagnosis of early-stage breast cancer and its treatment was not demonstrated.Peer reviewe

    Non-classical ProIL-1beta activation during mammary gland infection is pathogen-dependent but caspase-1 independent

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    Infection of the mammary gland with live bacteria elicits a pathogen-specific host inflammatory response. To study these host-pathogen interactions wild type mice, NF-kappaB reporter mice as well as caspase-1 and IL-1beta knockout mice were intramammarily challenged with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The murine mastitis model allowed to compare the kinetics of the induced cytokine protein profiles and their underlying pathways. In vivo and ex vivo imaging showed that E. coli rapidly induced NF-kappaB inflammatory signaling concomitant with high mammary levels of TNF-alpha, IL-1 alpha and MCP-1 as determined by multiplex analysis. In contrast, an equal number of S. aureus bacteria induced a low NF-kappaB activity concomitant with high mammary levels of the classical IL-1beta fragment. These quantitative and qualitative differences in local inflammatory mediators resulted in an earlier neutrophil influx and in a more extensive alveolar damage post-infection with E. coli compared to S. aureus. Western blot analysis revealed that the inactive proIL-1beta precursor was processed into pathogen-specific IL-1beta fragmentation patterns as confirmed with IL-1beta knockout animals. Additionally, caspase-1 knockout animals allowed to investigate whether IL-1beta maturation depended on the conventional inflammasome pathway. The lack of caspase-1 did not prevent extensive proIL-1beta fragmentation by either of S. aureus or E. coli. These non-classical IL-1beta patterns were likely caused by different proteases and suggest a sentinel function of IL-1beta during mammary gland infection. Thus, a key signaling nodule can be defined in the differential host innate immune defense upon E. coli versus S. aureus mammary gland infection, which is independent of caspase-1
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