32 research outputs found

    Fine structure of the low-frequency spectra of heart rate and blood pressure

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    BACKGROUND: The aim of this study was to explore the principal frequency components of the heart rate and blood pressure variability in the low frequency (LF) and very low frequency (VLF) band. The spectral composition of the R–R interval (RRI) and systolic arterial blood pressure (SAP) in the frequency range below 0.15 Hz were carefully analyzed using three different spectral methods: Fast Fourier transform (FFT), Wigner-Ville distribution (WVD), and autoregression (AR). All spectral methods were used to create time–frequency plots to uncover the principal spectral components that are least dependent on time. The accurate frequencies of these components were calculated from the pole decomposition of the AR spectral density after determining the optimal model order – the most crucial factor when using this method – with the help of FFT and WVD methods. RESULTS: Spectral analysis of the RRI and SAP of 12 healthy subjects revealed that there are always at least three spectral components below 0.15 Hz. The three principal frequency components are 0.026 ± 0.003 (mean ± SD) Hz, 0.076 ± 0.012 Hz, and 0.117 ± 0.016 Hz. These principal components vary only slightly over time. FFT-based coherence and phase-function analysis suggests that the second and third components are related to the baroreflex control of blood pressure, since the phase difference between SAP and RRI was negative and almost constant, whereas the origin of the first component is different since no clear SAP–RRI phase relationship was found. CONCLUSION: The above data indicate that spontaneous fluctuations in heart rate and blood pressure within the standard low-frequency range of 0.04–0.15 Hz typically occur at two frequency components rather than only at one as widely believed, and these components are not harmonically related. This new observation in humans can help explain divergent results in the literature concerning spontaneous low-frequency oscillations. It also raises methodological and computational questions regarding the usability and validity of the low-frequency spectral band when estimating sympathetic activity and baroreflex gain

    Engaging Undergraduates in Comparative Psychology: A Case Study

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    With many comparative psychologists teaching at small colleges and universities where resources are limited, maintaining a traditional animal laboratory housing rats or pigeons is not realistic for many of these researchers. One way to overcome this lack of overhead costs and extensive lab space, is to forge collaborations with local zoos and aquariums. Zoo and aquarium research projects provide a way to examine a wide range of species, which is an important tenet within the field of comparative psychology. Furthermore, many undergraduates are innately attracted to the prospect of working with exotic animals. Here, we propose utilizing visitor behavior research as a means to provide undergraduates with research experience within the field comparative psychology, as w ell as expose the general public to animal behavior research

    Impact of short-incubation MALDI-TOF MS on empiric antibiotic therapy in bloodstream infections caused by Pseudomonas aeruginosa, Enterococcus spp. and AmpC-producing Enterobacteriaceae

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    The impact of the short-incubation matrix-assisted laser desorption ionization time-of-flight (si-MALDI-TOF) mass spectrometry technique was evaluated in the treatment of bloodstream infections (BSIs) caused by Pseudomonas aeruginosa, Enterococcus spp., and Amp-C producing Enterobacteriaceae. A total of 124 bacteremia episodes were divided into 2 groups: i) si-MALDI-TOF group (n = 69) and ii) control group (n = 55). Identification by si-MALDI-TOF resulted in 12.8% increase in cases receiving appropriate antibiotic treatment within 48 h from blood culture draw. The importance of the rapid identification was emphasized in BSIs caused by enterococci (n = 62), where si-MALDI-TOF led to appropriate antibiotic treatment in 87.9% of cases (versus control group 65.5%, P = 0.036). Implementation of si-MALDI-TOF technology for microbial identification was associated with increased proportion of patients receiving effective antibiotic treatment within 48 h from blood culture draw. The effect was most significant in BSIs caused by enterococcal species and in a subgroup of immunosuppressed patients. (C) 2018 Elsevier Inc. All rights reserved.Peer reviewe

    Impact of pre-operative antimicrobial treatment on microbiological findings from endocardial specimens in infective endocarditis

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    Treatment of infective endocarditis (IE) should be initiated promptly. This might hamper the chances to identify the causative organism in blood cultures. Microbiological sampling of infected valve in patients undergoing surgery might identify the causative organism. The impact of pre-operative antimicrobial treatment on the yield of valve samples is not known. This study evaluated the impact of the duration of the pre-operative antibiotic treatment on valve culture and 16S rRNA PCR findings from resected endocardial samples. Patients meeting the modified Duke criteria of definite or possible IE and undergoing valve surgery due to IE during 2011–2016 were included from Southern Finland. Eighty-seven patients were included. In patients with shorter than 2 weeks of pre-operative antimicrobial treatment, PCR was positive in 91% (n = 42/46) and valve culture in 41% (n = 19/46) of cases. However, in patients who had 2 weeks or longer therapy before operation, PCR was positive in 53% (n = 18/34) and all valve cultures were negative. In 14% of patients, PCR had a diagnostic impact. In blood-culture negative cases (n = 13), PCR could detect the causative organism in ten patients (77%). These included five cases of Bartonella quintana, one Tropheryma whipplei, and one Coxiella burnetii. Long pre-operative antimicrobial treatment was shown to have a negative impact on microbiological tests done on resected endocardial material. After 2 weeks of therapy, all valve cultures were negative, but PCR was positive in half of the cases. PCR aided in diagnostic work-up, especially in blood culture negative cases.Peer reviewe

    Cut-off values to evaluate exercise-induced asthma in eucapnic voluntary hyperventilation test for children

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    Background and Aim The eucapnic voluntary hyperventilation (EVH) testing is a diagnostic tool for diagnostics of exercise-induced bronchoconstriction; while the testing has become more common among children, data on the test's feasibility among children remain limited. Our aim was to investigate EVH testing feasibility among children, diagnostic testing cut-off values, and which factors affect testing outcomes. Methods We recruited 134 patients aged 10-16 years with a history of exercise-induced dyspnoea and 100 healthy control children to undergo 6-min EVH testing. Testing feasibility was assessed by the children's ability to achieve >= 70% of the target minute ventilation of 30 times forced expiratory volume in 1 s (FEV1). Bronchoconstriction was assessed as a minimum of 8%, 10%, 12%, 15% or 20% fall in FEV1. Patient characteristics were correlated with EVH outcomes. Results Overall, 98% of the children reached >= 70%, 88% reached >= 80%, 79% reached >= 90% and 62% reached >= 100% of target ventilation in EVH testing; of children with a history of exercise-induced dyspnoea, the decline percentages were as follows: 24% (>= 8% fall), 17% (>= 10% fall), 10% (>= 12% fall), 6% (>= 15% fall) and 5% (>= 20% fall) in FEV1, compared to 11%, 4%, 3%, 1% and 0% among the healthy controls, respectively. Healthy controls and boys performed testing at higher ventilation rates (p <.05). Conclusion Eucapnic voluntary hyperventilation testing is feasible among children aged 10-16 years and has diagnostic value in evaluating exercise-induced dyspnoea among children. A minimum 10% fall in FEV1 is a good diagnostic cut-off value. Disease status appears to be important covariates.Peer reviewe

    InDEx – Industrial Data Excellence

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    InDEx, the Industrial Data Excellence program, was created to investigate what industrial data can be collected, shared, and utilized for new intelligent services in high-performing, reliable and secure ways, and how to accomplish that in practice in the Finnish manufacturing industry.InDEx produced several insights into data in an industrial environment, collecting data, sharing data in the value chain and in the factory environment, and utilizing and manipulating data with artificial intelligence. Data has an important role in the future in an industrial context, but data sources and utilization mechanisms are more diverse than in cases related to consumer data. Experiences in the InDEx cases showed that there is great potential in data utili zation.Currently, successful business cases built on data sharing are either company-internal or utilize an existing value chain. The data market has not yet matured, and third-party offerings based on public and private data sources are rare. In this program, we tried out a framework that aimed to securely and in a controlled manner share data between organizations. We also worked to improve the contractual framework needed to support new business based on shared data, and we conducted a study of applicable business models. Based on this, we searched for new data-based opportunities within the project consortium. The vision of data as a tradeable good or of sharing with external partners is still to come true, but we believe that we have taken steps in the right direction.The program started in fall 2019 and ended in April 2022. The program faced restrictions caused by COVID-19, which had an effect on the intensity of the work during 2020 and 2021, and the program was extended by one year. Because of meeting restrictions, InDEx collaboration was realized through online meetings. We learned to work and collaborate using digital tools and environments. Despite the mentioned hindrances, and thanks to Business Finland’s flexibility, the extension time made it possible for most of the planned goals to be achieved.This report gives insights in the outcomes of the companies’ work within the InDEx program. DIMECC InDEx is the first finalized program by the members of the Finnish Advanced Manufacturing Network (FAMN, www.famn.fi).</p
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