Data Quality of Citizen Science Observations of Organisms: Plausibility Estimation Based on Volunteered Geographic Information Context

In a growing number of Citizen Science projects, volunteers from the general public collect large amounts of observation data of organisms. Such data are an important contribution to biodiversity research, providing information on the distribution of species over large areas and long periods of time. In the current global biodiversity crisis, such information is urgently needed to support research and conservation efforts. One of the most important issues which must be addressed before these data can effectively be used, is data quality. This is a concern especially with data which are being collected in a casual way, without strict, formal protocols ensuring certain standards of data quality before or during the data collection process. There is great need for approaches which allow for assessing data quality of casual citizen science observations of organisms automatically, to cope with the large amounts of observation data which are produced by casual biodiversity citizen science projects. Casual citizen science observations of organisms are biological, but also geographical data, because they always possess location information. Collected mostly online and by untrained volunteers, they belong to the emerging domain of geographic information called Volunteered Geographic Information (VGI, Goodchild 2007). Approaches which are based on geographical criteria are therefore a promising avenue towards providing suitable methods for quality assessment. At the same time, casual citizen science observations of organisms are a special kind of VGI, because they mostly do not represent permanent objects, but rather have the nature of events which cannot be proven to be correct or incorrect. Quality assessment must therefore resort to proxy approaches such as estimating the plausibility of an observation in light of certain reference information. This thesis developed and evaluated novel approaches to quality assessment of casual citizen science observations of organisms based on estimating the plausibility of observations in light of VGI context. It employed two use cases of casual citizen science projects with two different areas of interest: ArtenFinder Rheinland-Pfalz (Germany), and the global project iNaturalist, of which data from California (USA) were used. In an intrinsic approach, geographic context is provided by neighboring observations from the same dataset which are transformed into species-specific observed communities, describing a species’ typical context of other species usually observed close-by. An extrinsic approach uses OpenStreetMap (OSM), a well-established global VGI project providing detailed geographic information on physical objects, for describing a species’ geographic context in the form of an OSM environment, consisting of the OSM features typically found in close proximity to a species’ observations. Plausibility of a new observation added to the dataset is estimated by comparing its context of neighboring observations or of OSM features to the species’ observed community or OSM environment. This comparison is achieved by using similarity indices. The intrinsic observed communities approach as well as the extrinsic OSM environments approach were evaluated by estimating the plausibility of plausible or implausible observations. This was done with real approved or rejected observations from the respective projects, but also with synthetic plausible and implausible observations created for this purpose. Evaluation proved that both approaches are able to distinguish between plausible and implausible observations based on VGI context, using similarity index values. The approaches estimate the plausibility of the location of an observation in light of surrounding observations or OSM context, and in light of the species identification given for the observation by the volunteer. Careful examination of evaluation results revealed differences in behavior of both approaches depending on the similarity index used. Results also partly differed between the data use cases. Variable spatial density of observations and OSM data has an influence on similarity index values. Observed communities were found to reflect biological and ecological properties of species, while OSM environments rarely do so. Both methods were also tested with a number of parameter changes, and results found basically stable with different parameter settings. Some modifications to the basic methodology of the approaches, such as applying auxiliary land cover data for focusing relevant geographic context or using observation frequency in similarity calculation, showed potential of improving results. Future work must seek to overcome the most important drawbacks and weaknesses of the approaches to plausibility estimation of casual citizen science observations of organisms developed in this work. They can be used only for species with an adequate base of previous observations, and for candidate observations in locations providing an adequate geographic context of observations or OSM data. Influence of variable spatial density of context information on plausibility estimation is a problem especially in the extrinsic OSM environments approach. Both methods should be combined with other approaches using other information about an observation, such as the observation date, or the observers’ experience

Kir4.1 Potassium Channel Subunit Is Crucial for Oligodendrocyte Development and In Vivo Myelination

To understand the cellular and in vivo functions of specific K^+ channels in glia, we have studied mice with a null mutation in the weakly inwardly rectifying K^+ channel subunit Kir4.1. Kir4.1−/− mice display marked motor impairment, and the cellular basis is hypomyelination in the spinal cord, accompanied by severe spongiform vacuolation, axonal swellings, and degeneration. Immunostaining in the spinal cord of wild-type mice up to postnatal day 18 reveals that Kir4.1 is expressed in myelin-synthesizing oligodendrocytes, but probably not in neurons or glial fibrillary acidic protein-positive (GFAP-positive) astrocytes. Cultured oligodendrocytes from developing spinal cord of Kir4.1−/− mice lack most of the wild-type K^+ conductance, have depolarized membrane potentials, and display immature morphology. By contrast, cultured neurons from spinal cord of Kir4.1−/− mice have normal physiological characteristics. We conclude that Kir4.1 forms the major K^+ conductance of oligodendrocytes and is therefore crucial for myelination. The Kir4.1 knock-out mouse is one of the few CNS dysmyelinating or demyelinating phenotypes that does not involve a gene directly involved in the structure, synthesis, degradation, or immune response to myelin. Therefore, this mouse shows how an ion channel mutation could contribute to the polygenic demyelinating diseases

A grounding-based ontology of data quality measures

Data quality and fitness for purpose can be assessed by data quality measures. Existing ontologies of data quality dimensions reflect, among others, which aspects of data quality are assessed and the mechanisms that lead to poor data quality. An understanding of which source of information is used to judge about data quality and fitness for purpose is, however, lacking. This article introduces an ontology of data quality measures by their grounding, that is, the source of information to which the data is compared to in order to assess their quality. The ontology is exemplified with several examples of volunteered geographic information (VGI), while also applying to other geographical data and data in general. An evaluation of the ontology in the context of data quality measures for OpenStreetMap (OSM) data, a well-known example of VGI, provides insights about which types of quality measures for OSM data have and which have not yet been considered in literature

Increased mesiotemporal delta activity characterizes virtual navigation in humans

Hippocampal theta or rhythmic slow activity (RSA) occurring during exploratory behaviors and rapid-eye-movement (REM) sleep is a characteristic and well-identifiable oscillatory rhythm in animals. In contrast, controversy surrounds the existence and electrophysiological correlates of this activity in humans. Some argue that the human hippocampal theta occurs in short and phasic bursts. On the contrary, our earlier studies provide evidence that REM-dependent mesiotemporal RSA is continuous like in animals but instead of the theta it falls in the delta frequency range. Here we used a virtual navigation task in 24 epilepsy patients implanted with foramen ovale electrodes. EEG was analyzed for 1-Hz wide frequency bins up to 10 Hz according to four conditions: resting, non-learning route-following, acquisition and recall. We found progressively increasing spectral power in frequency bins up the 4 Hz across these conditions. No spectral power increase relative to resting was revealed within the traditional theta band and above in any of the navigation conditions. Thus the affected frequency bins were below the theta band and were similar to those characterizing REM sleep in our previous studies providing further indication that it is delta rather than theta that should be regarded as a human analogue of the animal RSA

Leveraging OpenStreetMap to support flood risk management in municipalities : a prototype decision support system

Floods are considered the most common and devastating type of disasters world-wide. Therefore, flood management is a crucial task for municipalities- a task that requires dependable information to evaluate risks and to react accordingly in a disaster scenario. Acquiring and maintaining this information using official data however is not always feasible, especially for smaller municipalities. This issue could be approached by integrating the collaborative maps of OpenStreetMap (OSM). The OSM data is openly accessible, adaptable and continuously updated. Nonetheless, to make use of this data for effective decision support, the OSM data must be first adapted to the needs of decision makers. In the pursuit of this goal, this paper presents the OpenFloodRiskMap (OFRM)- a prototype for a OSM based spatial decision-support system. OFRM builds an intuitive and practical interface upon existing OSM data and services to enable decision makers to utilize the open data for emergency planning and response

Negotiating identities: ethnicity and social relations in a young offenders' institution

This article explores the situated nature of male prisoner identities in the late modern British context, using the contrasting theoretical frames of Sykes's (1958) indigenous model and Jacobs' (1979) importation model of prisoner subcultures and social relations. Drawing on eight months of ethnographic fieldwork in an ethnically, religiously and nationally diverse young offenders institution, consideration is given to how prisoners manage and negotiate difference, exploring the contours of racialization and racism which can operate in ambiguous and contradictory ways. Sociological understandings of identity, ethnicity, racialization and racism are used to inform a more empirically grounded theoretical criminology

The Association of Early Electrocardiographic Abnormalities With Brain Injury Severity and Outcome in Severe Traumatic Brain Injury

The aim of this study was to evaluate the frequency of electrocardiographic (ECG) abnormalities in the acute phase of severe traumatic brain injury (TBI) and the association with brain injury severity and outcome. In contrast to neurovascular diseases, sparse information is available on this issue. Data of adult patients with severe TBI admitted to the Intensive Care Unit (ICU) for intracranial pressure monitoring of a level-1 trauma center from 2002 till 2018 were analyzed. Patients with a cardiac history were excluded. An ECG recording was obtained within 24 h after ICU admission. Admission brain computerized tomography (CT)-scans were categorized by Marshall-criteria (diffuse vs. mass lesions) and for location of traumatic lesions. CT-characteristics and maximum Therapy Intensity Level (TILmax) were used as indicators for brain injury severity. We analyzed data of 198 patients, mean (SD) age of 40 +/- 19 years, median GCS score 3 [interquartile range (IQR) 3-6], and 105 patients (53%) had thoracic injury. In-hospital mortality was 30%, with sudden death by cardiac arrest in four patients. The incidence of ECG abnormalities was 88% comprising ventricular repolarization disorders (57%) mostly with ST-segment abnormalities, conduction disorders (45%) mostly with QTc-prolongation, and arrhythmias (38%) mostly of supraventricular origin. More cardiac arrhythmias were observed with increased grading of diffuse brain injury (p = 0.042) or in patients treated with hyperosmolar therapy (TILmax) (65%, p = 0.022). No association was found between ECG abnormalities and location of brain lesions nor with thoracic injury. Multivariate analysis with baseline outcome predictors showed that cardiac arrhythmias were not independently associated with in-hospital mortality (p = 0.097). Only hypotension (p = 0.029) and diffuse brain injury (p = 0.017) were associated with in-hospital mortality. In conclusion, a high incidence of ECG abnormalities was observed in patients with severe TBI in the acute phase after injury. No association between ECG abnormalities and location of brain lesions or presence of thoracic injury was present. Cardiac arrhythmias were indicative for brain injury severity but not independently associated with in-hospital mortality. Therefore, our findings likely suggest that ECG abnormalities should be considered as cardiac mimicry representing the secondary effect of traumatic brain injury allowing for a more rationale use of neuroprotective measures

Molecular recognition of histone lysine methylation by the Polycomb group repressor dSfmbt

Polycomb group (PcG) proteins repress transcription by modifying chromatin structure in target genes. dSfmbt is a subunit of the Drosophila melanogaster PcG protein complex PhoRC and contains four malignant brain tumour (MBT) repeats involved in the recognition of various mono- and dimethylated histone peptides. Here, we present the crystal structure of the four-MBT-repeat domain of dSfmbt in complex with a mono-methylated histone H4 peptide. Only a single histone peptide binds to the four-MBT-repeat domain. Mutational analyses show high-affinity binding with low peptide sequence selectivity through combinatorial interaction of the methyl-lysine with an aromatic cage and positively charged flanking residues with the surrounding negatively charged surface of the fourth MBT repeat. dSfmbt directly interacts with the PcG protein Scm, a related MBT-repeat protein with similar methyl-lysine binding activity. dSfmbt and Scm co-occupy Polycomb response elements of target genes in Drosophila and they strongly synergize in the repression of these target genes, suggesting that the combined action of these two MBT proteins is crucial for Polycomb silencing