Accurator: Nichesourcing for Cultural Heritage

With more and more cultural heritage data being published online, their usefulness in this open context depends on the quality and diversity of descriptive metadata for collection objects. In many cases, existing metadata is not adequate for a variety of retrieval and research tasks and more specific annotations are necessary. However, eliciting such annotations is a challenge since it often requires domain-specific knowledge. Where crowdsourcing can be successfully used for eliciting simple annotations, identifying people with the required expertise might prove troublesome for tasks requiring more complex or domain-specific knowledge. Nichesourcing addresses this problem, by tapping into the expert knowledge available in niche communities. This paper presents Accurator, a methodology for conducting nichesourcing campaigns for cultural heritage institutions, by addressing communities, organizing events and tailoring a web-based annotation tool to a domain of choice. The contribution of this paper is threefold: 1) a nichesourcing methodology, 2) an annotation tool for experts and 3) validation of the methodology and tool in three case studies. The three domains of the case studies are birds on art, bible prints and fashion images. We compare the quality and quantity of obtained annotations in the three case studies, showing that the nichesourcing methodology in combination with the image annotation tool can be used to collect high quality annotations in a variety of domains and annotation tasks. A user evaluation indicates the tool is suited and usable for domain specific annotation tasks

Measuring surface water quality using a low-cost sensor kit within the context of rural Africa

Monitoring water quality is done for a variety of reasons, including to determine whether water is suitable for drinking or agricultural purposes. In rural areas of Africa the traditional way of measuring water quality can be costly and time consuming. In this research, we have developed a low-cost water quality measuring device that designed to operate in the context of rural Africa. Firstly we select appropriate water quality sensors. Secondly we developed a water quality monitoring device that takes the contextual requirements and constraints of rural Africa into account. Lastly the device is evaluated and tested using water samples that were collected in rural Africa

Constraints on Recoil Leader Properties Estimated from X-ray Emissions in Aircraft-Triggered Discharges

During Airbus aircraft campaigns flying into thunderstorms in 2014–2016, X-rays were observed during two stages of aircraft-triggered lightning: nanosecond pulses of X-rays associated with negative leader steps and bursts of X-rays during recoil events. This work will focus on the observations of X-ray bursts associated with recoils. Recoils are observed as microsecond-fast changes in the local electric field, associated with large currents passing through the aircraft, and are found to sometimes be associated with bursts of X-rays. From over 200 aircraft-triggered lightning strikes, 54 recoil events were found to be associated with microsecond bursts of X-rays. The majority of the bursts consist of 1–3 X-ray pulses, with some bursts containing as many as 29 X-ray pulses. We compare the observed superposed X-ray spectrum with modeled spectra using a GEANT4 model of the detector and aircraft, to determine the source potential needed to accelerate the electrons that produce the observed X-rays. A model of the recoil leader was made to determine the gap distance and gap potential between the recoil leader and the aircraft. From the modeling, we determine a solution space for the gap and leader lengths where the gap length is constrained by the observed minimum and maximum times between the onset of the X-ray pulses and the onset of the current pulses detected at the aircraft (1 to 93 m). We also find two constraints from the fitting of the modeled spectra to the superposed spectrum, limiting the leader length to between 1 and ∼240 m.publishedVersio

Faecal volatile organic compounds analysis using field asymmetric ion mobility spectrometry : non-invasive diagnostics in paediatric inflammatory bowel disease

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), remains challenging to diagnose. Diagnostic work up carries a high burden, especially in paediatric patients, due to invasive endoscopic procedures. IBD is associated with alterations in intestinal microbiota composition. Faecal volatile organic compounds (VOCs) reflect gut microbiota composition. Aim of this study was to assess the diagnostic accuracy of faecal VOC profiling as non-invasive diagnostic biomarker for paediatric IBD

Hansenula polymorpha Aat2p is targeted to peroxisomes via a novel Pex20p-dependent pathway

Saccharomyces cerevisiae Aat2p contains a peroxisomal targeting signal type-1 and localizes to peroxisomes in oleate-grown cells, but not in glucose-grown cells. Here, we have investigated Aat2p from the yeast Hansenula polymorpha, which lacks a recognizable peroxisomal targeting signal. Aat2p tagged with GFP at its C terminus displays a dual cytosol-peroxisome localization in ethanol-grown cells. The partial peroxisomal localization of Aat2p persisted in the absence of the classical cycling receptors Pex5p and Pex7p but Aat2p targeting to peroxisomes was reduced in cells deleted for the matrix protein import factors PEX1, PEX2 and PEX13. Furthermore, we demonstrate that Aat2p targeting to peroxisomes requires Pex20p. Together, our data identify a Pex20p-dependent pathway for targeting Aat2p to peroxisomes

In‐Flight Observation of Positron Annihilation by ILDAS

We report a 511‐keV photon flux enhancement that was observed inside a thundercloud and is a result of positron annihilation. The observation was made with the In‐flight Lightning Damage Assessment System (ILDAS) on board of an A340 test aircraft. The aircraft was intentionally flying through a thunderstorm at 12‐km altitude over Northern Australia in January 2016. Two gamma ray detectors showed a significant count rate increase synchronously with fast electromagnetic field variations registered by an on‐board antenna. A sequence of 10 gamma ray enhancements was detected, each lasted for about 1 s. Their spectrum mainly consists of 511‐keV photons and their Compton component. The local electric activity during the emission was identified as a series of static discharges of the aircraft. A full‐scale Geant4 model of the aircraft was created to estimate the emission area. Monte Carlo simulation indicated that the positrons annihilated in direct vicinity or in the aircraft body.publishedVersio

Cyanogen in NGC 1851 red giant branch and asymptotic giant branch stars: Quadrimodal distributions

The Galactic globular cluster NGC 1851 has raised much interest since Hubble Space Telescope photometry revealed that it hosts a double subgiant branch. Here we report on our homogeneous study into the cyanogen (CN) band strengths in the red giant branc

Optimized sampling conditions for fecal volatile organic compounds analysis by means of field asymmetric ion mobility spectrometry

Background Fecal volatile organic compounds (VOCs) are increasingly considered as potential non-invasive, diagnostic biomarkers for various gastrointestinal diseases. Knowledge of influence of sampling conditions on VOC outcomes is limited. We aimed to evaluate effects of sampling conditions on fecal VOC profiles and to assess under which conditions an optimal diagnostic accuracy in the discrimination between pediatric inflammatory bowel disease (IBD) and controls could be obtained. Methods Fecal samples from de novo treatment-naïve pediatric IBD patients and healthy controls (HC) were used to assess effects of sampling conditions compared to the standard operating procedure (reference standard), defined as 500mg of sample mass, diluted with 10mL tap water, using field asymmetric ion mobility spectrometry (FAIMS). Results A total of 17 IBD (15CD and 2 UC) and 25 HC were included. IBD and HC could be discriminated with high accuracy (accuracy=0.93, AUC=0.99, p<0.0001). Smaller fecal sample mass resulted in a decreased diagnostic accuracy (300mg accuracy=0.77; AUC=0.69, p=0.02; 100mg accuracy=0.70, AUC=0.74, p=0.003). A loss of diagnostic accuracy was seen towards increased numbers of thaw-freeze cycles (one cycle: accuracy=0.61, AUC=0.80, p=0.0004, two cycles: accuracy=0.64, AUC=0.56, p=0.753, three cycles: accuracy=0.57, AUC=0.50, p=0.5101) and when samples were kept at room temperature for 180 minutes prior to analysis (accuracy=0.60, AUC=0.51, p=0.46). Diagnostic accuracy of VOC profiles was not significantly influenced by storage duration differences of 20 months. Conclusion Application of 500mg sample mass analyzed after one thaw-freeze cycle, showed best discriminative accuracy for differentiation of IBD and HC. VOC profiles and diagnostic accuracy were significantly affected by sampling conditions, underlining the need for implementation of standardized protocols in fecal VOC analysis

Differentiation between pediatric irritable bowel syndrome and inflammatory bowel disease based on fecal scent : proof of principle study

The diagnostic work-up of pediatric irritable bowel syndrome (IBS) and functional abdominal pain-not otherwise specified (FAP-NOS) commonly includes invasive tests for discrimination from inflammatory bowel disease (IBD). As this carries a high burden on patients, an ongoing need exists for development of noninvasive diagnostic biomarkers for IBS and FAP-NOS. Several studies have shown microbiota alterations in IBS/FAP, which are considered to be reflected by fecal volatile organic compounds (VOCs). The object of the study was to evaluate whether pediatric IBS/FAP-NOS could be discriminated from IBD and healthy controls by fecal VOC analysis. IBS/FAP-NOS was diagnosed according to the ROME IV criteria, and de novo IBD patients and healthy controls (HCs) aged 4 to 17 years were matched on age and sex. Fecal VOCs were analyzed by means of field asymmetric ion mobility spectrometry. Fecal VOCs of 15 IBS/FAP-NOS, 30 IBD (15 ulcerative colitis, 15 Crohn's disease) patients and 30 HCs were analyzed and compared. Differentiation between IBS/FAP-NOS and IBD was feasible with high accuracy (area under the curve [AUC], 0.94; 95% confidence interval [CI], 0.88-1; P < 0.00001). IBS/FAP-NOS profiles could not be differentiated from HCs (AUC, 0.59; 95% CI, 0.41-0.77; P = 0.167), whereas IBD profiles could with high accuracy (AUC, 0.96; 95% CI, 0.93-1; P < 0.00001). Pediatric IBS/FAP-NOS could be differentiated from IBD by fecal VOC analysis with high accuracy, but not from healthy controls. The latter finding limits the potential of fecal VOCs to serve as a diagnostic biomarker for IBS/FAP-NOS. However, VOC could possibly serve as additional noninvasive biomarker to differentiate IBS/FAP-NOS from IBD