1,271 research outputs found

    Do all roads lead to rome? The potential of different approaches to diagnose Aelurostrongylus abstrusus infection in cats

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    An infection with the cat lungworm, Aelurostrongylus abstrusus, can be subclinical, but it can also cause severe respiratory clinical signs. Larvae excretion, antibody levels, clinical assessment findings of the respiratory system and diagnostic imaging findings were recorded and compared for six cats with experimental aelurostrongylosis. In five cats, patency started 33–47 days post infection (pi), but two cats excreted larvae only in long intervals and low numbers. Positive ELISA results were observed in four cats with patent aelurostrongylosis, starting between five days before and 85 days after onset of patency. One seropositive cat remained copromicroscopically negative. Mild respiratory signs were observed in all cats examined. A computed tomographic (CT) examination of the lungs displayed distinct alterations, even in absence of evident clinical signs or when larvae excretion was low or negative. The thoracic radiograph evaluation correlated with the CT results, but CT was more distinctive. After anthelmintic treatment in the 25th week post infection, pulmonary imaging findings improved back to normal within 6–24 weeks. This study shows that a multifaceted approach, including diagnostic imaging, can provide a clearer diagnosis and monitoring of disease progression. Furthermore, a CT examination provides an alternative to post mortem examination and worm counts in anthelmintic efficacy studies

    The 2010 M 87 VHE flare and its origin: the multi-wavelength picture

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    The giant radio galaxy M 87, with its proximity (16 Mpc) and its very massive black hole ((3 - 6) \times 10^9 M_solar), provides a unique laboratory to investigate very high energy (E>100 GeV; VHE) gamma-ray emission from active galactic nuclei and, thereby, probe particle acceleration to relativistic energies near supermassive black holes (SMBH) and in relativistic jets. M 87 has been established as a VHE gamma-ray emitter since 2005. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In 2008, a rise in the 43 GHz Very Long Baseline Array (VLBA) radio emission of the innermost region (core; extension of < 100 Rs ; Schwarzschild radii) was found to coincide with a flaring activity at VHE. This had been interpreted as a strong indication that the VHE emission is produced in the direct vicinity of the SMBH. In 2010 a flare at VHE was again detected triggering further multi-wavelength (MWL) observations with the VLBA, Chandra, and other instruments. At the same time, M 87 was also observed with the Fermi-LAT telescope at MeV/GeV energies, the European VLBI Network (EVN), and the Liverpool Telescope (LT). Here, preliminary results from the 2010 campaign will be reported.Comment: 6 pages, 2 figures; Procceedings of the workshop "High Energy Phenomena in Relativistic Outflows III" (HEPRO III), Barcelona, June 27 - July 1, 201

    Identification of occult metastases of medullary thyroid carcinoma by pentagastrin-stimulated intravenous calcitonin sampling followed by targeted surgery

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    BACKGROUND: High calcitonin (CT) serum levels suggest metastatic spread in medullary thyroid carcinoma (MTC) after thyroidectomy. In limited disease stages, however, morphological investigations including ultrasound, magnetic resonance imaging (MRI) and 18F-FDG positron emission tomography ([18F]FDG-PET) may often fail to identify exact tumour sites. OBJECTIVE: The aim of the present study was to establish an improved strategy to identify small cervical tumours by combining pentagastrin stimulation with bilateral cervical intravenous CT sampling followed by high-resolution ultrasound. DESIGN AND PATIENTS: Six MTC patients were examined, of whom five patients already had bilateral neck dissection. Five patients had sporadic MTC, and one patient suffered from MEN2a. RESULTS: Retrospective analysis of all patients revealed a highly sensitive positive correlation between an early calcitonin peak (20–40 s after pentagastrin injection) and site of cervical tumour affection. Postinterventional ultrasound examination of the affected regions of the neck revealed suspicious presence; in some cases small lymph nodes of less than 1 cm in size were then surgically excised. On histology, small tumours could be identified in four patients. Postsurgical examination revealed a clear decline of basal serum calcitonin levels in four patients (between −41% and −100%). In two patients CT normalized to baseline levels (< 10 pg/ml) and in another two patients CT rendered to near normal (14 and 17 pg/ml). CONCLUSION: Pentagastrin stimulation-based intravenous catheter sampling may be beneficial in the diagnostic work-up of MTC after thyroidectomy. Our data show that an early calcitonin peak (20–40 s after administration of pentagastrin) helps to identify tumour-affected regions

    A Spectacular VHE Gamma-Ray Outburst from PKS 2155-304 in 2006

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    Since 2002 the VHE (>100 GeV) gamma-ray flux of the high-frequency peaked BL Lac PKS 2155-304 has been monitored with the High Energy Stereoscopic System (HESS). An extreme gamma-ray outburst was detected in the early hours of July 28, 2006 (MJD 53944). The average flux above 200 GeV observed during this outburst is ~7 times the flux observed from the Crab Nebula above the same threshold. Peak fluxes are measured with one-minute time scale resolution at more than twice this average value. Variability is seen up to ~600 s in the Fourier power spectrum, and well-resolved bursts varying on time scales of ~200 seconds are observed. There are no strong indications for spectral variability within the data. Assuming the emission region has a size comparable to the Schwarzschild radius of a ~10^9 solar mass black hole, Doppler factors greater than 100 are required to accommodate the observed variability time scales.Comment: 4 pages, 3 figures; To appear in the Proceedings of the 30th ICRC (Merida, Mexico

    Early and Later Perceptions and Reactions to the COVID-19 Pandemic in Germany: On Predictors of Behavioral Responses and Guideline Adherence During the Restrictions

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    In March 2020, the German government enacted measures on movement restrictions and social distancing due to the COVID-19 pandemic. As this situation was previously unknown, it raised numerous questions about people’s perceptions of and behavioral responses to these new policies. In this context, we were specifically interested in people’s trust in official information, predictors for self-prepping behavior and health behavior to protect oneself and others, and determinants for adherence to social distancing guidelines. To explore these questions, we conducted three studies in which a total of 1,368 participants were surveyed (Study 1 N=377, March 2020; Study 2 N=461, April 2020; Study 3 N=530, April 2021) across Germany between March 2020 and April 2021. Results showed striking differences in the level of trust in official statistics (depending on the source). Furthermore, all three studies showed congruent findings regarding the influence of different factors on the respective behavioral responses. Trust in official statistics predicted behavioral responses in all three studies. However, it did not influence adherence to social distancing guidelines in 2020, but in 2021. Furthermore, adherence to social distancing guidelines was associated with higher acceptance rates of the measures and being older. Being female and less right-wing orientated were positively associated with guidelines adherence only in the studies from 2020. This year, political orientation moderated the association between acceptance of the measures and guideline adherence. This investigation is one of the first to examine perceptions and reactions during the COVID-19 pandemic in Germany across 1year and provides insights into important dimensions that need to be considered when communicating with the public
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