Validating archetypes for the Multiple Sclerosis Functional Composite

Background Numerous information models for electronic health records, such as openEHR archetypes are available. The quality of such clinical models is important to guarantee standardised semantics and to facilitate their interoperability. However, validation aspects are not regarded sufficiently yet. The objective of this report is to investigate the feasibility of archetype development and its community-based validation process, presuming that this review process is a practical way to ensure high-quality information models amending the formal reference model definitions. Methods A standard archetype development approach was applied on a case set of three clinical tests for multiple sclerosis assessment: After an analysis of the tests, the obtained data elements were organised and structured. The appropriate archetype class was selected and the data elements were implemented in an iterative refinement process. Clinical and information modelling experts validated the models in a structured review process. Results Four new archetypes were developed and publicly deployed in the openEHR Clinical Knowledge Manager, an online platform provided by the openEHR Foundation. Afterwards, these four archetypes were validated by domain experts in a team review. The review was a formalised process, organised in the Clinical Knowledge Manager. Both, development and review process turned out to be time- consuming tasks, mostly due to difficult selection processes between alternative modelling approaches. The archetype review was a straightforward team process with the goal to validate archetypes pragmatically. Conclusions The quality of medical information models is crucial to guarantee standardised semantic representation in order to improve interoperability. The validation process is a practical way to better harmonise models that diverge due to necessary flexibility left open by the underlying formal reference model definitions. This case study provides evidence that both community- and tool- enabled review processes, structured in the Clinical Knowledge Manager, ensure archetype quality. It offers a pragmatic but feasible way to reduce variation in the representation of clinical information models towards a more unified and interoperable model

Validating archetypes for the Multiple Sclerosis Functional Composite

Background Numerous information models for electronic health records, such as openEHR archetypes are available. The quality of such clinical models is important to guarantee standardised semantics and to facilitate their interoperability. However, validation aspects are not regarded sufficiently yet. The objective of this report is to investigate the feasibility of archetype development and its community-based validation process, presuming that this review process is a practical way to ensure high-quality information models amending the formal reference model definitions. Methods A standard archetype development approach was applied on a case set of three clinical tests for multiple sclerosis assessment: After an analysis of the tests, the obtained data elements were organised and structured. The appropriate archetype class was selected and the data elements were implemented in an iterative refinement process. Clinical and information modelling experts validated the models in a structured review process. Results Four new archetypes were developed and publicly deployed in the openEHR Clinical Knowledge Manager, an online platform provided by the openEHR Foundation. Afterwards, these four archetypes were validated by domain experts in a team review. The review was a formalised process, organised in the Clinical Knowledge Manager. Both, development and review process turned out to be time- consuming tasks, mostly due to difficult selection processes between alternative modelling approaches. The archetype review was a straightforward team process with the goal to validate archetypes pragmatically. Conclusions The quality of medical information models is crucial to guarantee standardised semantic representation in order to improve interoperability. The validation process is a practical way to better harmonise models that diverge due to necessary flexibility left open by the underlying formal reference model definitions. This case study provides evidence that both community- and tool- enabled review processes, structured in the Clinical Knowledge Manager, ensure archetype quality. It offers a pragmatic but feasible way to reduce variation in the representation of clinical information models towards a more unified and interoperable model

Übertragung von Kontaminationen durch Umluftbetrieb sowie Leckagen in zentralen und dezentralen Lüftungsanlagen

Durch den Einsatz von Raumlufttechnischen (RLT) Anlagen lassen sich Schadstoffkonzentrationen in Räumen effektiv reduzieren. Dies gilt grundsätzlich auch für die Konzentration von luftgetragenen Krankheitserregern. Es existieren Anlagentypen, die aufgrund ihrer Konfiguration ein Risikopotential bieten. Hierbei kann kontaminierte Abluft über die RLT-Anlage in nicht kontaminierte Bereiche verteilt werden. In dieser Studie wurde betrachtet, wie hoch die Übertragung derartiger Kontaminationen durch den Umluftbetrieb sowie durch eventuell vorhandene interne Leckagen in zentralen und dezentralen Lüftungsanlagen ist. Hierfür wurden verschiedene Fälle ausgewählt und die Verdünnung der Konzentration bestimmt. Neben einer dezentralen Lüftung für einen einzelnen Raum wurden zentrale Lüftungssysteme mit einer unterschiedlichen Anzahl angeschlossener Räume und damit verschiedenen Gesamtvolumenströmen betrachtet. Bei dem dezentralen Fall und einem Umluftanteil von 40 % am Zuluftvolumenstrom liegt die Verdünnung bei 60 %. Da ein dezentrales System typischerweise raumweise arbeitet, ist eine Übertragung in andere Räume über die raumlufttechnische Anlage ausgeschlossen. Bei einem zentralen System erhöht sie sich mit steigender Anzahl der versorgten Räume auf 80 – ca. 95 % unter der Annahme einer einzigen Kontaminationsquelle in nur einem der Räume. Die Versorgung mehrerer Räume führt gleichzeitig zu einem höheren Gesamtzuluftvolumenstrom im Vergleich zu dem dezentralen Fall. Die Verdünnung vergrößert sich je geringer der Leckage- bzw. Umluftanteil am Zuluftvolumenstrom ist. Im nächsten Schritt wurde für ein kleines Büro ein Vergleich der Belastung pro m3 Raumvolumen als Maß für die Kontamination mit vier verschiedenen Lüftungsszenarien (unbelüftet sowie nach DIN EN 16798-1 Kategorie I bis III) vorgenommen. Abschließend wurden für drei Bürogrößen Belastungen für die Fälle mit Umluftanteilen von 20 % und von 40 % berechnet und mit Luftvolumenströmen nach Kategorie II und III verglichen. Außerdem wurde für eine Anlage ohne Umluft betrachtet, wie sich interne Leckagen (bspw. durch Wärmerückgewinnungssysteme selbst oder den Einbau dieser) von 5% auswirken. Es ist zu erkennen, dass sich die Luftqualität bei der Nutzung einer dezentralen Lüftungsanlage und einem Umluftanteil von 40 % um eine Kategorie verschlechtert. Zu beachten ist, dass es sich um eine vereinfachte Rechnung des ungünstigsten Falls handelt, bei der die Wirkung von Filtern nicht betrachtet wurde. Bei Einbeziehung von Filterleistungen in die Berechnung ist mit einer Verringerung der Belastung zu rechnen [1]. Insgesamt ist zu bemerken, dass durch den Einsatz von Umluft in zentralen Lüftungssystemen das Risiko der Übertragungen von Kontaminationen aus der Abluft in die Zuluft nur sehr gering erhöht wird. Das Vorhandensein von Leckagen (Annahme 5%) durch Wärmerückgewinnungssysteme führt zu einem unerheblichen Einfluss. Dennoch sollte stets der Außenluftluftanteil möglichst hoch sein, um die Raumlufthygiene auf einem hohen Standard zu halten.BMWI, 03EN1038, EnOB: MinInfekt - Notwendige Luftmengen zur Minderung des Infektionsrisikos über Aerosole effektiv und energieeffizient bereitstelle

What four decades of earth observation tell us about land degradation in the Sahel?

The assessment of land degradation and the quantification of its effects on land productivity have been both a scientific and political challenge. After four decades of Earth Observation (EO) applications, little agreement has been gained on the magnitude and direction of land degradation in the Sahel. The large number of EO datasets and methods associated with the complex interactions among biophysical and social drivers of ecosystem changes make it difficult to apply aggregated EO indices for these non-linear processes. Hence, while many studies stress that the Sahel is greening, others indicate no trend or browning. The different generations of sensors, the granularity of studies, the study period, the applied indices and the assumptions and/or computational methods impact these trends. Consequently, many uncertainties exist in regression models between rainfall, biomass and various indices that limit the ability of EO science to adequately assess and develop a consistent message on the magnitude of land degradation. We suggest several improvements: (1) harmonize time-series data, (2) promote knowledge networks, (3) improve data-access, (4) fill data gaps, (5) agree on scales and assumptions, (6) set up a denser network of long-term field-surveys and (7) consider local perceptions and social dynamics. To allow multiple perspectives and avoid erroneous interpretations, we underline that EO results should not be interpreted without contextual knowledge

Mapping gains and losses in woody vegetation across global tropical drylands

Woody vegetation in global tropical drylands is of significant importance for both the interannual variability of the carbon cycle and local livelihoods. Satellite observations over the past decades provide a unique way to assess the vegetation long-term dynamics across biomes worldwide. Yet, the actual changes in the woody vegetation are always hidden by interannual fluctuations of the leaf density, because the most widely used remote sensing data are primarily related to the photosynthetically active vegetation components. Here, we quantify the temporal trends of the nonphotosynthetic woody components (i.e., stems and branches) in global tropical drylands during 2000–2012 using the vegetation optical depth (VOD), retrieved from passive microwave observations. This is achieved by a novel method focusing on the dry season period to minimize the influence of herbaceous vegetation and using MODerate resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data to remove the interannual fluctuations of the woody leaf component. We revealed significant trends (P < 0.05) in the woody component (VODwood) in 35% of the areas characterized by a nonsignificant trend in the leaf component (VODleaf modeled from NDVI), indicating pronounced gradual growth/decline in woody vegetation not captured by traditional assessments. The method is validated using a unique record of ground measurements from the semiarid Sahel and shows a strong agreement between changes in VODwood and changes in ground observed woody cover (r2 = 0.78). Reliability of the obtained woody component trends is also supported by a review of relevant literatures for eight hot spot regions of change. The proposed approach is expected to contribute to an improved assessment of, for example, changes in dryland carbon pools

Biophysical and structural characterization of proton-translocating NADH-dehydrogenase (complex I) from the strictly aerobic yeast Yarrowia lipolytica

AbstractMitochondrial proton-translocating NADH-dehydrogenase (complex I) is one of the largest and most complicated membrane bound protein complexes. Despite its central role in eukaryotic oxidative phosphorylation and its involvement in a broad range of human disorders, little is known about its structure and function. Therefore, we have started to use the powerful genetic tools available for the strictly aerobic yeast Yarrowia lipolytica to study this respiratory chain enzyme. To establish Y. lipolytica as a model system for complex I, we purified and characterized the multisubunit enzyme from Y. lipolytica and sequenced the nuclear genes coding for the seven central subunits of its peripheral part. Complex I from Y. lipolytica is quite stable and could be isolated in a highly pure and monodisperse state. One binuclear and four tetranuclear iron–sulfur clusters, including N5, which was previously known only from mammalian mitochondria, were detected by EPR spectroscopy. Initial structural analysis by single particle electron microscopy in negative stain and ice shows complex I from Y. lipolytica as an L-shaped particle that does not exhibit a thin stalk between the peripheral and the membrane parts that has been observed in other systems

Antipsychotic Withdrawal Symptoms: A Systematic Review and Meta-Analysis

Objective Avoiding withdrawal symptoms following antipsychotic discontinuation is an important factor when planning a safe therapy. We performed a systematic review and meta-analysis concerning occurrence of withdrawal symptoms after discontinuation of antipsychotics. Data Sources We searched the databases CENTRAL, Pubmed, and EMBASE with no restriction to the beginning of the searched time period and until October 1, 2019 (PROSPERO registration no. CRD42019119148). Study Selection Of the 18,043 screened studies, controlled and cohort trials that assessed withdrawal symptoms after discontinuation of oral antipsychotics were included in the random-effects model. Studies that did not implement placebo substitution were excluded from analyses. The primary outcome was the proportion of individuals with withdrawal symptoms after antipsychotic discontinuation. We compared a control group with continued antipsychotic treatment in the assessment of odds ratio and number needed to harm (NNH). Data Extraction We followed guidelines by the Cochrane Collaboration, PRISMA, and MOOSE. Results Five studies with a total of 261 individuals were included. The primary outcome, proportion of individuals with withdrawal symptoms after antipsychotic discontinuation, was 0.53 (95% CI, 0.37–0.70; I2 = 82.98%, P < 0.01). An odds ratio of 7.97 (95% CI, 2.39–26.58; I2 = 82.7%, P = 0.003) and NNH of 3 was calculated for the occurrence of withdrawal symptoms after antipsychotic discontinuation. Conclusion Withdrawal symptoms appear to occur frequently after abrupt discontinuation of an oral antipsychotic. The lack of randomized controlled trials with low risk of bias on antipsychotic withdrawal symptoms highlights the need for further research

Revisiting the coupling between NDVI trends and cropland changes in the Sahel drylands:a case study in western Niger

The impact of human activities via land use/cover changes on NDVI trends is critical for an improved understanding of satellite-observed changes in vegetation productivity in drylands. The dominance of positive NDVI trends in the Sahel, the so-called re-greening, is sometimes interpreted as a combined effect of an increase in rainfall and cropland expansion or agricultural intensification. Yet, the impact of changes in land use has yet to be thoroughly tested and supported by empirical evidence. At present, no studies have considered the importance of the different seasonal NDVI signals of cropped and fallowed fields when interpreting NDVI trends, as both field types are commonly merged into a single ‘cropland’ class. We make use of the distinctly different phenology of cropped and fallowed fields and use seasonal NDVI curves to separate these two field types. A fuzzy classifier is applied to quantify cropped and fallowed areas in a case study region in the southern Sahel (Fakara, Niger) on a yearly basis between 2000 and 2014. We find that fallowed fields have a consistently higher NDVI than unmanured cropped fields and by using two seasonal NDVI metrics (the amplitude and the decreasing rate) derived from the MODIS time series, a clear separation between classes of fields is achieved (r = 0.77). The fuzzy classifier can compute the percentage of a pixel (250 m) under active cultivation, thereby alleviating the problem of small field sizes in the region. We find a predominant decrease in NDVI over the period of analysis associated with an increased area of cropped fields at the expense of fallowed fields. Our findings couple cropping abandonment (more frequent fallow years) with positive NDVI trends and an increase in the percentage of the cropped area (fallow period shortening) with negative trends. These findings profoundly impact our understanding of greening and browning trends in agrarian Sahelian drylands and in other drylands of developing countries characterized by limited use of fertilizers