45 research outputs found
Online dynamic flat-field correction for MHz Microscopy data at European XFEL
The X-ray microscopy technique at the European X-ray free-electron laser
(EuXFEL), operating at a MHz repetition rate, provides superior contrast and
spatial-temporal resolution compared to typical microscopy techniques at other
X-ray sources. In both online visualization and offline data analysis for
microscopy experiments, baseline normalization is essential for further
processing steps such as phase retrieval and modal decomposition. In addition,
access to normalized projections during data acquisition can play an important
role in decision-making and improve the quality of the data. However, the
stochastic nature of XFEL sources hinders the use of existing flat-flied
normalization methods during MHz X-ray microscopy experiments. Here, we present
an online dynamic flat-field correction method based on principal component
analysis of dynamically evolving flat-field images. The method is used for the
normalization of individual X-ray projections and has been implemented as an
online analysis tool at the Single Particles, Clusters, and Biomolecules and
Serial Femtosecond Crystallography (SPB/SFX) instrument of EuXFEL.Comment: 14 pages, 7 figure
Caring for a patient with rabies: implications of the Milwaukee protocol for infection control and public health measures.
This article discusses the infection control and public health measures taken whilst managing a case of laboratory-confirmed rabies, and the challenges faced in implementing these measures. Case management requires intensive multi-disciplinary co-ordination. The Milwaukee protocol, which to date has five reported human rabies survivors associated with its use, has been suggested as a potential management pathway for human rabies. Consensus among hospital and public health clinicians would aid future deployment of this approach in selected cases
Persistence of Livestock Associated MRSA CC398 in Humans Is Dependent on Intensity of Animal Contact
INTRODUCTION: The presence of Livestock Associated MRSA (LA-MRSA) in humans is associated with intensity of animal contact. It is unknown whether the presence of LA-MRSA is a result of carriage or retention of MRSA-contaminated dust. We conducted a longitudinal study among 155 veal farmers in which repeated nasal and throat swabs were taken for MRSA detection. Periods with and without animal exposure were covered. METHODS: Randomly, 51 veal calf farms were visited from June-December 2008. Participants were asked to fill in questionnaires (nâ=â155) to identify potential risk factors for MRSA colonisation. Nasal and throat swabs were repeatedly taken from each participant for approximately 2 months. Swabs were analysed for MRSA and MSSA by selective bacteriological culturing. Spa-types of the isolates were identified and a ST398 specific PCR was performed. Data were analyzed using generalized estimation equations (GEE) to allow for correlated observations within individuals. RESULTS: Mean MRSA prevalence was 38% in farmers and 16% in family members. Presence of MRSA in farmers was strongly related to duration of animal contact and was strongly reduced in periods with absence of animal contact (-58%). Family members, especially children, were more often carriers when the farmer was a carrier (ORâ=â2,
Effects of body size, sex, parental care and moult strategies on auk diving behaviour outside the breeding season
Information on seabird foraging behaviour outside the breeding season is currently limited. This knowledge gap is critical as this period is energetically demanding due to postâfledging parental care, feather moult and changing environmental conditions. Based on speciesâ body size, postâfledging parental strategy and primary moult schedule we tested predictions for key aspects of foraging behaviour (Maximum Dive Depth (MDD), Daily Time Submerged (DTS) and Diurnal Dive Activity (DDA)) using dive depth data collected from three seabird species (common guillemot Uria aalge, razorbill Alca torda and Atlantic puffin Fratercula arctica) from the end of the breeding season (July) to midâwinter (January). We found partial support for predictions associated with body size; guillemots had greater MDD than razorbills but MDD did not differ between razorbills and puffins, despite the former being 35% heavier. In accordance with sexual monomorphism in all three species, MDD did not differ overall between the sexes. However, in guillemots and razorbills there were sexâspecific differences, such that male guillemots made deeper dives than females, and males of both species had higher DTS. In contrast, there were no marked sex differences in dive behaviour of puffins in July and August in accordance with their lack of postâfledging parental care and variable moult schedule. We found support for the prediction that diving effort would be greater in midâwinter compared to the period after the breeding season. Despite reduced daylight in midâwinter, this increase in DTS occurred predominantly during the day and only guillemots appeared to dive nocturnally to any great extent. In comparison to diving behaviour of these species recorded during the breeding season, MDD was shallower and DTS was greater during the nonâbreeding period. Such differences in diving behaviour during the postâbreeding period are relevant when identifying potential energetic bottlenecks, known to be key drivers of seabird population dynamics