325 research outputs found

    Grazing and Virus-Induced Mortality of Microbial Populations Before and During the Onset of Annual Hypoxia in Lake Erie

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    Lake Erie is the most productive of the North American Great Lakes and experiences annual periods of hypolimnetic hypoxia with unknown consequences for the microbial food web. We established the abundances and mortality rates of microbes in Lake Erie during thermal stratification and determined how they varied with changes in bottom-water dissolved oxygen concentrations. The microbial plankton community (heterotrophic bacteria, Cyanobacteria, eukaryotic phytoplankton, nanozooplankton, microzooplankton) was quantified in surface and bottom waters along with measurements of herbivory and bacterivory rates on eukaryotic and prokaryotic picoplankton and rates of viral lysis of bacteria. High rates of grazing mortality of prokaryotic picoplankton (1.4 +/- 0.6 d(-1)) and eukaryotic algae (0.66 +/- 0.27 d(-1)) and significant correlations between microzooplankton abundances and all picoplankton populations quantified demonstrated the strong impacts of grazing on Lake Erie picoplanktonic communities. Microbial herbivory accounted for half of total phytoplankton mortality per day. Bacterivory and viral lysis turned over 85% of the heterotrophic bacterial community each day. During the onset of hypolimnetic hypoxia, abundances of ciliates and rotifers decreased significantly and herbivory was undetectable. Concurrently, bacterivory persisted at rates equal to those found in shallower oxygenated waters, and abundances of heterotrophic nanoflagellates did not change significantly. These results suggest that, during hypoxia events in Lake Erie, herbivory by microzooplankton is disrupted, but bacterivory by heterotrophic nanoflagellates persists. Finally, rates of viral lysis of heterotrophic bacteria were higher in the hypolimnion than in surface waters, suggesting that increased viral lysis may enhance regeneration of organic matter in bottom waters during hypoxic events

    Measurements and simulations of wakefields at the Accelerator Test Facility 2

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    Wakefields are an important factor in accelerator design, and are a real concern when preserving the low beam emittance in modern machines. Charge dependent beam size growth has been observed at the Accelerator Test Facility (ATF2), a test accelerator for future linear collider beam delivery systems. Part of the explanation of this beam size growth is wakefields. In this paper we present numerical calculations of the wakefields produced by several types of geometrical discontinuities in the beam line as well as tracking simulations to estimate the induced effects. We also discuss precision beam kick measurements performed with the ATF2 cavity beam position monitor system for a test wakefield source in a movable section of the vacuum chamber. Using an improved model independent method we measured a wakefield kick for this movable section of about 0.49  V/pC/mm, which, compared to the calculated value from electromagnetic simulations of 0.41  V/pC/mm, is within the systematic error

    Development of Integrated Programs for Aerospace-Vehicle Design (IPAD)

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    Integrated Programs for Aerospace Vehicle Design (IPAD) system design requirements are given. The information is based on the IPAD User Requirements Document (D6-IPAD-70013-D) and the Integrated Information Processing Requirements Document (D6-IPAD-70012-D). General information about IPAD and a list of the system design requirements that are to be satisfied by the IPAD system are given. The system design requirements definition is to be considered as a baseline definition of the IPAD system design requirements

    Competitiveness and the export performance of the euro area

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    Chapter 1 provides an overview and assessment of the price competitiveness and export performance of the euro area and the larger euro area countries, as well as an evaluation of how standard equations have been able to explain actual export developments. Chapter 2 carries out a constant market share analysis for the euro area and thereby sheds light on the reasons for movements in aggregate export market shares by looking at the sectoral and geographical composition of euro area exports. Chapter 3 looks at the evolution of the technological competitiveness of the euro area and major competitors – proxied by patenting activity and R&D expenditure – and analyses some structural indicators of competitiveness using survey data. Chapter 4 then looks at the impact of FDI on competitiveness and export performance. Finally, Chapter 5 summarises the main findings of the report, but also critically evaluates their importance and implications.

    Adaptive magnetic resonance-guided neurovascular-sparing radiotherapy for preservation of erectile function in prostate cancer patients

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    Background and purpose: Erectile dysfunction is a common adverse effect of external beam radiation therapy for localized prostate cancer (PCa), likely as a result of damage to neural and vascular tissue. Magnetic resonance-guided online adaptive radiotherapy (MRgRT) enables high-resolution MR imaging and paves the way for neurovascular-sparing approaches, potentially lowering erectile dysfunction after radiotherapy for PCa. The aim of this study was to assess the planning feasibility of neurovascular-sparing MRgRT for localized PCa. Materials and methods: Twenty consecutive localized PCa patients, treated with standard 5×7.25 Gy MRgRT, were included. For these patients, neurovascular-sparing 5×7.25 Gy MRgRT plans were generated. Dose constraints for the neurovascular bundle (NVB), the internal pudendal artery (IPA), the corpus cavernosum (CC), and the penile bulb (PB) were established. Doses to regions of interest were compared between the neurovascular-sparing plans and the standard clinical pre-treatment plans. Results: Neurovascular-sparing constraints for the CC, and PB were met in all 20 patients. For the IPA, constraints were met in 19 (95%) patients bilaterally and 1 (5%) patient unilaterally. Constraints for the NVB were met in 8 (40%) patients bilaterally, in 8 (40%) patients unilaterally, and were not met in 4 (20%) patients. NVB constraints were not met when gross tumor volume (GTV) was located dorsolaterally in the prostate. Dose to the NVB, IPA, and CC was significantly lower in the neurovascular-sparing plans. Conclusions: Neurovascular-sparing MRgRT for localized PCa is feasible in the planning setting. The extent of NVB sparing largely depends on the patient's GTV location in relation to the NVB

    Depressive symptoms predict the incidence of common chronic diseases in women and men in a representative community sample

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    Background: Depression, the most frequent and harmful mental disorder, has been associated with specific somatic diseases as the leading cause of death. The purposes of this prospective study were to predict incident chronic diseases based on baseline depressive symptoms and to test sex-dependent effects. Methods: In a representative German community sample of over 12 000 participants, baseline depressive symptoms (assessed using the Patient Health Questionnaire-9) were tested as a predictor of new onset of cardiovascular disease (CVD), chronic obstructive lung disease, diabetes, cancer, and migraine at 5-year follow-up. To study disease incidence, we created subsamples for each chronic disease by excluding participants who already had the respective disease at baseline. Potential confounders were included in logistic regression models and sex-specific analyses were performed. Results: Controlling for demographic characteristics and loneliness, in men and women, baseline depressive symptoms were predictive of CVD, chronic obstructive lung disease, diabetes, and migraine, but not of cancer. When we additionally adjusted for metabolic and lifestyle risk factors, there was an 8% increase of chronic obstructive lung disease and migraine per point of depressive symptoms. There was a trend for CVD (4%; p = 0.053). Sex-sensitive analyses revealed trends for the relevance of depressive symptoms for CVD in men (p = 0.065), and for diabetes in women (p = 0.077). Conclusions: These findings underscore the need to implement screening for depression in the treatment of major somatic illnesses. At the same time, depressed patients should be screened for metabolic and lifestyle risk factors and for somatic diseases and offered lifestyle interventions

    Neurovascular-Sparing MR-Guided Adaptive Radiotherapy in Prostate Cancer; Defining the Potential Population for Erectile Function-Sparing Treatment

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    BACKGROUND: Magnetic resonance-guided adaptive radiotherapy (MRgRT) enables neurovascular-sparing treatment for localized prostate cancer (PCa). The aim of this treatment is preservation of erectile function by sparing the neurovascular bundles, the internal pudendal arteries, the corpora cavernosa, and the penile bulb. Internal pudendal arteries, corpora cavernosa, and penile bulb sparing can generally be achieved in all patients, but NVB sparing can be challenging due to its proximity to the prostate and is therefore dependent on tumor location. PCa patients that have sufficient erectile function at baseline and favorable tumor characteristics might benefit from this treatment. Currently, it is unclear what proportion of patients are eligible for neurovascular-sparing treatment and to what extent this is technically feasible. AIM: To define the eligibility and technical feasibility for neurovascular-sparing MRgRT in intermediate-risk localized PCa patients. METHODS: A consecutive series of men that received 5 × 7.25 gray (Gy) MRgRT for localized PCa were included. Baseline erectile function was assessed using the International Index of Erectile Function (IIEF)-5 questionnaire. Additionally, the ability of sparing the neurovascular bundles was assessed in all patients. Per neurovascular-sparing protocol, the dominant intraprostatic lesion with a 4 mm isotropic margin should receive 34.44 Gy in ≄ 99% of the volume (i.e., high-dose area). When the high-dose area directly borders or overlaps the NVB because of a dorsolateral position of the dominant intraprostatic lesion, sparing of the NVB was considered not feasible on that side. OUTCOMES: Patient-reported IIEF-5 baseline questionnaires and the technical feasibility of NVB sparing were assessed. RESULTS: Of the 102 men that completed the IIEF-5 questionnaire at baseline, 49.0% of patients reported to have an IIEF-5 score of ≄ 17. In those patients, the NVB could technically have been spared bilaterally in 20.0% and unilaterally in 68.0%. CLINICAL IMPLICATIONS: Our findings define the potential population for neurovascular-sparing MRgRT for localized PCa and indicate the proportion in which the NVB can technically be spared. STRENGTH & LIMITATIONS: The major strength of this study is the prospective collection of data. The limitations include that the neurovascular-sparing feasibility definition is based on pre-clinical planning data. CONCLUSION: A substantial group of 49.0% of patients in our study had mild or no erectile dysfunction at baseline. Of these patients, the NVB could technically have been spared bilaterally in 20.0% and unilaterally in 68.0% during MRgRT. Trials need to assess the effect of neurovascular-sparing MRgRT on erectile function. Teunissen FR, van der Voort van Zyp JRN, Verkooijen HM, et al., Neurovascular-Sparing MR-Guided Adaptive Radiotherapy in Prostate Cancer; Defining the Potential Population for Erectile Function-Sparing Treatment. J Sex Med 2022;19:1196-1200
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