Mapping the field of international comparative research in school social work

This article maps the field of international comparative research in school social work. For this purpose, a systematic literature review was conducted and subjected to a narrative synthesis. The review reveals 11 publications that are predominantly non-empirical, take mainly Asian, European, North American countries and Australia and New Zealand into account, and are focused on profession-related and sociopolitical aspects of school social work. A synthesis of school social work practice themes transcending national boundaries emerged from the findings, covering child-, family-, school-, and community-related issues. Accordingly, children are predominantly confronted with similar issues, irrespective of the place where they live, such as violence toward themselves, at home, in school, and in their community. Bearing in mind methodological challenges when carrying out comparative studies, recommendations include the conduct of practice-focused studies that generate new stimuli to improve already well-developed practices in a culturally appropriate way and enable mutual learning among school social workers

Development of Electrochemical Biosensors for Clinical Analysis

In this thesis, the beneficial properties of silver nanoparticles (AgNPs) are employed in the development of electrochemical assays for clinical analysis. AgNPs are the most abundant commercialized nanocompound with a production of 350 t per year. Besides their manifold uses based on their antibacterial, antiviral, antifungal and antimicrobial properties, e.g. in coating of medicinal products, they are also employed for various clinical biosensors. While most sensing applications rely on optical detection techniques such as surface plasmon resonance (SPR), surface-enhanced-Raman-scattering (SERS), metal-enhanced fluorescence (MEF) or fluorescence emission, there has been some research in the field of electrochemical biosensors using AgNPs, as well. They are used for modification of the electrode surface or less commonly as labels. The suitability for the use of the respective biosensor at the point-of-care (POC) was assessed carefully based on criteria like ease of handling, storage ability, cost, time consumption and need of sample pretreatment. Sandwich Immunoassay for NT-proBNP Detection The first experimental part of this work focuses on the benefit of using AgNPs as electrochemical label, instead of the more commonly employed gold nanoparticles (AuNPs). Using an electrochemical detection strategy with a sequence of oxidation and reduction reactions, lowest limits of detection (LODs) were reached for both metallic nanoparticles (mNPs). When exchanging gold with silver in a simple sandwich immunoassay for the blood biomarker N-terminal prohormone brain natriuretic peptide (NT-proBNP) on screen-printed carbon electrodes (SPCEs), the LOD is decreased by a factor of 6, while maintaining the same or better assay reliability and ease of surface functionalization. Moreover, the addition of hydrochloric acid, inevitable for the electrochemical detection of gold due the high Au stability, is removed. This makes the AgNP assay better suited for POC applications. In order to adjust the procedure better to the needs at the POC, i.e. ease of handling and miniaturization, while increasing the analytical performance, this assay was transferred into a microfluidic chip. The chip comprises the SPCE, double-sided adhesive tape with cut out channel design and a PMMA top with in- and outlet as well as a cavity on the inside. This renders it low-cost and easy to produce and enables the integration of all-dried reagents into one chip. The use of a trehalose matrix in combination with a suitable oxygen scavenger stabilizes the AgNPs against oxidation by air oxygen and renders the chips stable over 18 weeks at 4 °C. With a LOD of 0.26 ng·mL-1 in buffer and 0.56 ng·mL-1 in undiluted human serum, the microfluidic sensor exhibits a sensitivity below the clinically relevant threshold for chronic heart failure (HF) of 1 ng·mL-1. Also, the reproducibility is greatly increased with a mean standard deviation (SD) of 6% in comparison to the standard immunoassay with 15%. Aggregation Assay for Creatinine Detection The second experimental part shows the development of an electrochemical aggregation assay for the detection of the renal function biomarker creatinine. In neutral or slightly acidic medium, picric acid (PA) interacts selectively with the tautomeric form of creatinine, while creatinine molecules form hydrogen bonds among each other as well. AgNPs can be functionalized with PA via electrostatic interactions. These picric acid-modified AgNPs (PA-AgNPs) aggregate in the presence of creatinine and the grade of aggregation is a measure for the concentration of the analyte. This system was employed by others in combination with an optical detection. Here, an electrochemical detection via differential pulse voltammetry (DPV) is investigated, which is based on the increasing distance between AgNP and electrode surface upon aggregation. Different nanoparticle (NP) sizes and modifications were tested and 10 nm AgNPs modified with 10 μM PA are ideal for electrochemical detection and show effective aggregation. To render it accessible for POC strategies, the detection was transferred into an all-dried approach without any loss of performance. It was found that the sensitivity can be controlled by changes in the PA-AgNP to sample ratio making the assay easily adjustable to various matrices with different concentration ranges. With a 2:3 ratio, a LOD as low as 76 μM was reached with a mean SD of 12%. This system was also successfully applied in 1:10 diluted synthetic urine (surin) matrix covering a majority of the physiological range (0.4-2 mM in 1:10 diluted surin) without further optimization

Variabilität und Stabilität körperlicher Aktivität bei Kindern und Jugendlichen – Aktivitätskompensation aus Public Health Perspektive

Regular physical activity (PA) is associated with various short- and long-term health benefits in children and adolescents and can prevent suffering from non-communicable diseases in adulthood (Janssen & LeBlanc, 2010; Poitras et al., 2016; Warburton & Bredin, 2017). To address these benefits, PA guidelines exist worldwide (Rütten & Pfeifer, 2016; World Health Organization, 2010). Despite these recommendations and the known health benefits, inactivity of children and adolescents remains a global issue (Guthold et al., 2020). Though numerous interventions have aimed to modulate children’s PA to the recommended levels, PA promotion programs have had mixed success and changes are typically not sustained (Dobbins et al., 2013; Messing et al., 2019). To develop interventions and to efficiently promote PA levels, there is a need to have a deeper look on (habitual) PA behavior in terms of stability and variability of PA as this may help to understand and promote activity behavior of children and adolescents in a holistic way. In general, PA levels in children and adolescents underly variability that occurs in everybody’s daily life (affected by for example weather, season, age…), as it is unlikely on a within subject level, that one would engage in the same amount of PA each day. Overall, it is determined that the intra-individual variability of children’s and youths’ PA level deviates from their mean PA level with ±20-25% (Eisenmann & Wickel, 2009; Levin et al., 1999). Further impacts based on various factors associated with health behavior (socioecological model (McLeroy et al., 1988)) can cause greater changes in PA behavior than the regular intra-individual variability of ±20-25%. In Manuscript A we illustrate how this variability is or is not affected by policy restrictions during the Covid-19 pandemic and therefore, we conducted a rapid review aiming to get on overview of changes in PA levels during lockdown. However, in the context of PA, the issue of stability of PA is particularly relevant from a public health perspective as epidemiological studies highlight that continuous and stable activity behavior reduces the risk of several diseases (Hernelahti et al., 2004; Twisk et al., 2000). According to Rowland (1998), there exists a biological control mechanism (ActivityStat hypothesis), that leads to stable PA levels, i.e. activity compensation. Activity compensation suggests, that an increase of PA at one time point may result in a subsequent decrease of PA at another time point (and vice versa), in order to maintain energy stability over time (Gomersall et al., 2013; Rowland, 1998). However, activity compensation is poorly understood. As such, this thesis wants to explore activity compensation in children and adolescents from a public health perspective using different measurement approaches. To measure variability and stability, respectively compensatory behavior, different measurement methods are available. Firstly, to gain information about the compensatory mechanism, device-based approaches can be used as these produce quantifiable and accurate values (Reilly et al., 2008). One example for device-based methods is accelerometry. These devices need to be validated and calibrated for each age group as body structures and thus, locomotion is not equal in children and adults (Ridgers & Fairclough, 2011; Strath et al., 2013) (Manuscript B). Having then appropriate measurement methods on hand, compensatory behavior can be assessed. Overall, there is an ongoing debate concerning whether activity compensation occurs (Reilly, 2011; Wilkin, 2011) and further, little is known about how compensation may occur, to whom it may occur, and any reasons for its occurrence. Thus, before conducting empirical studies concerning activity compensation, there is a need to get knowledge about the state of research. Therefore, we performed a systematic review to get an overview of compensatory behavior in children and adolescents aged 0-19 years (Manuscript C). By including only studies with a device-based approach, compensatory mechanisms were analyzed across different categories, which seemed to be helpful for understanding compensation. Within the 77 included studies, the ActivityStat hypothesis could be neither confirmed nor rejected with a prevalence of compensation in 50% of the included studies and a tendency of compensation within interventional studies. Further, the results highlighted that little research had explored influencing factors of compensatory responses. Finally, there was a lack of consistency in methodology used to assess compensation (e.g., between-person or group analyses, varying timespans of potential compensatory responses, study designs, etc.), making it difficult to draw firm conclusions surrounding the existence of an ActivityStat. To address these limitations, we performed a secondary data analysis of the CRreActivity study data (Manuscript D) and focused on the timespan of compensation as well as sociodemographic data (age, weight status and socioeconomic status (SES)) as potential moderators for compensatory behavior in (pre)adolescent girls. The data indicated compensatory behavior within-day (morning-afternoon) as well as between-day (weekdays-weekend days) in about 60% of all observation points. Further multilevel analysis indicated that sociodemographic data did not moderate activity compensation and this behavior is rather a quite individual behavior. Summarizing the findings from the previous compensation articles, inconclusive results concerning activity compensation in children and adolescents could be identified. Even if device-based activity monitoring is essential in providing quantitative data and assessing compensatory behavior, it seems not to be sufficient enough to holistically understand activity compensation in children and adolescents. Especially, to provide insights into the behavioral context of activity compensation as well as perception and influencing factors, subjective measurement tools can be helpful to gain a deeper and more holistic understanding of activity compensation. Thus, the following articles focus on subjective measurements and their usefulness in measuring activity behaviors, respectively activity compensation. To focus on individuals and get more information about perception and influencing factors, we conducted a qualitative study (ComPAS study) addressing adolescents aged 11-15 years (Manuscript E). By comparing an activity diary over one week with a habitual weekly schedule (self-reported), we analyzed deviations in PA levels and potential subsequent compensatory responses. Our analyses indicated inconclusive results concerning occurrence and timespan of compensatory responses. Furthermore, few adolescents perceived that they compensated. However, the interviews identified potential influencing factors for compensatory behavior (e.g., social support, weather, routines…) and thus, may explain the inconclusive results. Especially social support played an important role in activity compensation. This was also confirmed in our last empirical study (MoMo study). Thus, in Manuscript F, the aim of this study was to investigate the influence of the family environment, specifically SES, parental support, and having siblings on Covid-19-related changes of PA and screen time behavior in 317 (170 boys, 147 girls) German preschool children using longitudinal data. The results supported the findings of Manuscript E, stating that even if preschool children had a lack of activity due to closure of sports clubs and kindergarten (variability of habitual PA), children receiving parental support seemed to compensate this loss of activity by being active at home (supported by their parents/siblings). In summary, the findings highlighted that there are various levels that could lead to perturbation and thus changes in one’s habitual PA behavior. Following the ActivityStat hypothesis, this variability could be compensated by adapting the PA levels followed by a stable PA level. Our studies investigating compensatory behavior with various measurement methods suggested that whilst compensatory responses may not be consistently predicted, most children and adolescents, regardless of their age, sex/gender or other sociodemographic data, tend to compensate their activity to some degree. Further, the findings of this thesis support a complex interaction between biological control (stating the existence of an ActivityStat) and one’s (social and physical) environment (e.g., social support, weather, routines), though further exploration of compensation thresholds and timespans of compensatory responses are needed by using a combination of device-based and subjective measurement methods.Regelmäßige körperliche Aktivität (kA) ist mit verschiedenen kurz- und langfristigen gesundheitlichen Vorteilen für Kinder und Jugendliche verbunden und kann dazu beitragen, chronische, nicht übertragbare Krankheiten im Erwachsenenalter zu verhindern (Janssen & LeBlanc, 2010; Poitras et al., 2016; Warburton & Bredin, 2017). Um von diesen Vorteilen zu profitieren, existieren weltweit Aktivitätsrichtlinien (Rütten & Pfeifer, 2016; World Health Organization, 2010). Trotz dieser Empfehlungen und der bekannten gesundheitlichen Vorteile bleibt die Inaktivität von Kindern und Jugendlichen ein globales Problem (Guthold et al., 2020). Obwohl zahlreiche Interventionen darauf abzielten, die Aktivität von Kindern auf die empfohlenen Levels zu modulieren, waren Aktivitätsförderungsprogramme nur teilweise erfolgreich, und Veränderungen werden in der Regel nicht aufrechterhalten (Dobbins et al., 2013; Messing et al., 2019). Um Interventionen zu entwickeln und kA Levels effizient zu fördern, ist es erforderlich, einen tieferen Blick auf (gewohnheitsmäßiges) kA-Verhalten im Hinblick auf Stabilität und Variabilität zu werfen, da dies dazu beitragen kann, das Aktivitätsverhalten von Kindern und Jugendlichen ganzheitlich zu verstehen und zu fördern. Generell unterliegt die kA von Kindern und Jugendlichen einer Variabilität, die im täglichen Leben jedes Einzelnen auftritt (beeinflusst durch z.B. Wetter, Jahreszeit, Alter usw.), da es unwahrscheinlich ist, dass jemand auf individueller Ebene jeden Tag die gleiche Menge an Aktivität aufweist. Insgesamt wird festgestellt, dass die intra-individuelle Variabilität des kA-Niveaus von Kindern und Jugendlichen mit ±20-25 % von ihrem mittleren kA-Niveau abweicht (Eisenmann & Wickel, 2009; Levin et al., 1999). Weitere Einflüsse basierend auf verschiedenen Faktoren im Zusammenhang mit Gesundheitsverhalten (sozioökologisches Modell (McLeroy et al., 1988)) können größere Veränderungen im Aktivitätsverhalten verursachen als die reguläre intraindividuelle Variabilität von ±20-25%. In Manuskript A veranschaulichen wir, wie die Variabilität der kA nach politischen Einschränkungen, die das gewohnheitsmäßige Verhalten beeinflussen, aussehen könnte. Wir führten hierzu ein Rapid Review durch, um einen Überblick über Veränderungen im Aktivitätsverhalten während der Covid-19-Pandemie zu erhalten. Im Zusammenhang mit kA ist jedoch die Frage der Stabilität von kA aus Public-Health-Perspektive besonders relevant, da epidemiologische Studien darauf hinweisen, dass kontinuierliches und stabiles Aktivitätsverhalten das Risiko für verschiedene Krankheiten reduziert (Hernelahti et al., 2004; Twisk et al., 2000). Laut Rowland (1998) gibt es einen biologischen Steuermechanismus (ActivityStat Hypothese), der zu stabilen Aktivitätsniveaus führt, d.h. Aktivitätskompensation. Aktivitätskompensation deutet darauf hin, dass eine Zunahme der kA zu einem bestimmten Zeitpunkt zu einer nachfolgenden Abnahme der kA zu einem anderen Zeitpunkt führen kann (und umgekehrt), um die Energiestabilität im Laufe der Zeit aufrechtzuerhalten (Gomersall et al., 2013; Rowland, 1998). Die Aktivitätskompensation ist jedoch unzureichend untersucht und verstanden. Diese Arbeit versucht daher, die Aktivitätskompensation bei Kindern und Jugendlichen aus Public-Health-Perspektive unter Verwendung unterschiedlicher Messmethoden zu erforschen. Zur Messung von Variabilität und Stabilität bzw. Kompensationsverhalten stehen verschiedene Messmethoden zur Verfügung. Zunächst können gerätebasierte Ansätze verwendet werden, um Informationen über den Kompensationsmechanismus zu erhalten, da diese quantifizierbare und genaue Werte liefern (Reilly et al., 2008). Ein Beispiel für gerätebasierte Methoden sind Beschleunigungssensoren. Diese Geräte müssen für jede Altersgruppe kalibriert werden muss, da sich Körpereigenschaften und somit die Fortbewegung bei Kindern und Erwachsenen unterscheiden (Ridgers & Fairclough, 2011; Strath et al., 2013) (Manuskript B). Sobald geeignete Messmethoden zur Verfügung stehen, kann das kompensatorische Verhalten bewertet werden. Generell gibt es eine anhaltende Debatte darüber, ob Aktivitätskompensation stattfindet (Reilly, 2011; Wilkin, 2011), und darüber hinaus ist wenig darüber bekannt, wie Kompensation auftreten kann, bei wem sie auftreten kann und aus welchen Gründen sie auftritt. Bevor empirische Studien zur Aktivitätskompensation durchgeführt werden, ist es erforderlich, einen Überblick über den Forschungsstand zu erhalten. Daher haben wir als ersten Schritt eine systematische Übersichtsarbeit geschrieben, um einen Überblick über das Kompensationsverhalten bei Kindern und Jugendlichen zu erhalten (Manuskript C). Es wurden nur Studien mit gerätebasiertem Ansatz eingeschlossen und Kompensationsmechanismen in verschiedenen Kategorien analysiert, was für das Verständnis der Kompensation hilfreich zu sein schien. Anhand der 77 eingeschlossenen Studien konnte die ActivityStat Hypothese weder bestätigt noch abgelehnt werden, wobei in 50% der eingeschlossenen Studien eine Tendenz zur Kompensation in interventionsbasierten Studien festgestellt wurde. Die Ergebnisse zeigten jedoch, dass wenig Forschung die beeinflussenden Faktoren kompensatorischer Reaktionen untersucht hatte. Schließlich mangelte es an Konsistenz in der angewandten Methodik zur Bewertung von Kompensation (z. B. zwischen Personen oder Gruppenanalysen, unterschiedliche Zeiträume, Studiendesigns usw.), was es schwierig macht, konsistente Schlussfolgerungen zur Existenz eines ActivityStat zu ziehen. Um diese Einschränkungen zu adressieren, führten wir eine Sekundärdatenanalyse der CReActivity Daten durch (Manuskript D) und konzentrierten uns auf den Zeitraum der Kompensation sowie auf soziodemografische Daten (Alter, Gewichtsstatus und sozioökonomischer Status) als potenzielle Moderatoren für kompensatorisches Verhalten bei präadoleszenten Mädchen. Die Daten zeigten kompensatorisches Verhalten innerhalb des Tages (Morgen-Nachmittag) sowie zwischen den Tagen (Wochentage-Wochenendtage) bei etwa 60% aller Beobachtungspunkte. Mehrebenen-Analysen deuteten darauf hin, dass soziodemografische Daten keine Aktivitätskompensation moderierten und dieses Verhalten eher ein individuelles Verhalten ist. Zusammenfassend konnten aus den vorherigen Artikeln zur Kompensation uneindeutige Ergebnisse bezüglich der Aktivitätskompensation bei Kindern und Jugendlichen identifiziert werden. Selbst wenn die gerätebasierte Aktivitätserfassung hilfreich ist, um quantitative Daten zu generieren und kompensatorisches Verhalten zu bewerten, scheint sie nicht ausreichend genug zu sein, um die Aktivitätskompensation bei Kindern und Jugendlichen ganzheitlich zu verstehen. Insbesondere zur Erklärung des Verhaltenskontexts der Aktivitätskompensation sowie der Wahrnehmung und Einflussfaktoren können subjektive Messinstrumente hilfreich sein. Daher haben sich die folgenden Artikel auf subjektive Messungen und deren Nützlichkeit zur Erfassung von Aktivitätsverhalten bzw. Aktivitätskompensation konzentriert. Um sich auf Einzelpersonen zu konzentrieren und mehr Informationen über Wahrnehmung und Einflussfaktoren zu erhalten, führten wir eine qualitative Studie (ComPAS-Studie) mit Jugendlichen im Alter von 11-15 Jahren durch (Manuskript E). Durch den Vergleich eines Aktivitätstagebuchs über eine Woche mit einem gewohnheitsmäßigen Wochenplan (selbstberichtet) analysierten wir Abweichungen und potenzielle anschließende kompensatorische Reaktionen. Unsere Analysen zeigten inkonsistente Ergebnisse hinsichtlich der Häufigkeit und des Zeitrahmens der Kompensation. Darüber hinaus gaben nur wenige Jugendliche an, dass sie kompensierten. Die Interviews identifizierten jedoch potenziell beeinflussende Faktoren für kompensatorisches Verhalten (z. B. soziale Unterstützung, Wetter, Routinen usw.) und können somit die widersprüchlichen Ergebnisse erklären. Insbesondere soziale Unterstützung spielte eine wichtige Rolle bei der Aktivitätskompensation. Dies wurde auch in unserer dritten empirischen Studie (MoMo-Studie) veranschaulicht. Die Studie in Manuskript F hatte zum Ziel, den Einfluss des familiären Umfelds, insbesondere des sozioökonomischen Status, der elterlichen Unterstützung und des Vorhandenseins von Geschwistern auf Covid-19-bedingte Veränderungen des körperlichen Aktivitäts- und Bildschirmzeitverhaltens bei 317 (170 Jungen, 147 Mädchen) deutschen Vorschulkindern anhand von Längsschnittdaten zu untersuchen. Die Ergebnisse unterstützten die Ergebnisse von Manuskript E und zeigten, dass selbst, wenn Vorschulkinder aufgrund der Schließung von Sportvereinen und Kindergärten einen Mangel an Aktivität hatten (Variabilität der habituellen kA), Kinder, die elterliche Unterstützung erhielten, diesen Verlust an Aktivität durch Aktivitäten zu Hause zu kompensieren schienen (unterstützt von ihren Eltern/Geschwistern). Zusammenfassend zeigen die Ergebnisse, dass es verschiedene Faktoren gibt, die zu Störungen des gewohnheitsmäßigen Aktivitätsverhaltens führen können. Nach der ActivityStat-Hypothese könnte diese Variabilität durch Anpassung der Aktivitätsniveaus und anschließendes Erreichen eines stabilen Aktivitätsniveaus kompensiert werden. Unsere Studien zur Erforschung kompensatorischen Verhaltens legten nahe, dass zwar kompensatorische Reaktionen nicht konsistent vorhergesagt werden können, die meisten Kinder und Jugendlichen unabhängig von Alter, Geschlecht oder anderen soziodemografischen Daten aber dazu tendieren, ihre Aktivität in gewissem Maße zu kompensieren. Darüber hinaus belegen die Ergebnisse dieser Arbeit eine komplexe Interaktion zwischen der biologischen Kontrolle (d. h. dem Vorhandensein eines ActivityStats) und dem (sozialen und physischen) Umfeld (z. B. soziale Unterstützung, Wetter, Routinen). Eine weitere Exploration von Kompensationsgrenzen und Zeitrahmen ist jedoch durch die Verwendung einer Kombination von gerätebasierten und subjektiven Messmethoden erforderlich

Family predictors of physical activity change during the COVID-19 lockdown in preschool children in Germany

The COVID-19 pandemic is associated with crucial changes in children’s daily life including their physical activity (PA) and screen time (ST). Among preschool children, the family represents an important factor for sufficient PA levels by being the gatekeeper for PA. Thus, the aim of this study was to investigate the influence of the family environment, specifically SES, parental support, and having siblings on COVID-19-related changes of PA and ST behavior in 317 (170 boys, 147 girls) German preschool children using longitudinal data. Our results indicate a decline in total amount of sports-related PA, an increase in outdoor play, as well as an increase in leisure ST in preschool children. The changes in total amount of PA differed between children with different levels of parental support as well as in dependence on having siblings. Furthermore, levels of outdoor play and ST in preschool children were influenced by environmental factors like having access to their own garden. We conclude that the family environment (parental support as well as physical environment) is highly relevant for PA and ST levels in preschool children. To provide every child with PA opportunities during potential future lockdowns, restriction policies should be adapted and parents need sophisticated information about the importance of their support and thus the PA levels of their children

Physical activity of children and adolescents who use a wheelchair: a systematic review

AbstractPhysical activity has numerous health benefits for people with physical disabilities. Nevertheless, activity levels are often below recommended levels. To promote physical activity among children and adolescents who use a wheelchair as their primary source of mobility, this systematic review explores the physical activity patterns of this group. A systematic search of PubMed, Sports Medicine &amp; Education Index, Web of Science, and SPORTDiscus was performed, included articles were synthesized in terms of duration, intensity, and settings in which physical activity occurred, as well as the physical activity measurement methods. Nine articles were included. The mean overall physical activity level across the included studies was 98 minutes per day (range: 78–115 minutes per day). Two articles analysed the duration of physical activity at different intensities (very light physical activity, light physical activity (LPA), moderate to vigorous physical activity (MVPA) and intensities near to maximum). Within the included articles, both subjective and objective measurement methods were used. Due to the small number of articles, combined with small sample sizes, there is not enough evidence to answer the research questions sufficiently. Nevertheless, the review provides an overview of actual research and clearly shows that the physical activity values are insufficiently researched. There is a need for further research on the scope, types and settings of physical activity in the target group. </jats:p

Wissensstandsanalyse zu Qualität, Verbraucherschutz und Verarbeitung ökologischer Lebensmittel

Zielsetzung des Projektes war es, den aktuellen Stand des Wissens zur Qualität und Verarbeitung ökologischer Lebensmittel sowie zum Verbraucherschutz aufzuzeigen und zu bewerten. Das Projektteam setzte sich aus Wissenschaftlern des Forschungsinstituts für biologischen Landbau (Deutschland und Schweiz), des Büros für Lebensmittelkunde, des Forschungsrings für Biologisch-Dynamische Wirtschaftsweise e.V. sowie des Fachgebiets Ökologische Lebensmittelqualität und Ernährungskultur der Universität Kassel zusammen. In dem zeitlich sehr begrenzten Projekt fokussierte die Arbeitsgruppe die Betrachtung auf folgende Themenkomplexe und Produktgruppen: Bereich Qualität - Ernährung - Sensorik - Ökospezifische Qualitäten - Authentizität und Rückverfolgbarkeit Bereich Verarbeitung - Rohwaren/Lagerung und Technologien für die Produktgruppen: -- Getreide -- Milch -- Fleisch -- Obst und Gemüse und Erzeugnisse aus diesen - Nachhaltigkeit im Unternehmen und entlang der Prozesskette - Verpackung Vorhandenes Wissen, aktuelle Fragestellungen und Entwicklungsrichtungen wurden nach thematisch angepassten Vorgehensweisen identifiziert und anhand internationaler Literatur und Experteninterviews diskutiert. Zu allen Themenkomplexen wurden kurze und allgemeinverständliche Reports erstellt, die einen schnellen und fundierten Überblick zum aktuellen Stand des Wissens und zu eventuellen Wissenslücken geben. Der Abschlussreport wurde in deutscher und englischer Sprache veröffentlicht. Insgesamt wurde festgestellt, dass in den betrachteten Themenkomplexen erheblicher Bedarf an Forschung und Entwicklung sowie an Wissenstransfer besteht. Neben einer Reihe von Detailfragen sind grundlegende Themen, wie beispielsweise das Anforderungsprofil an eine „ökologische Verarbeitung“, nicht hinreichend erforscht und geklärt. Diese Arbeiten sind jedoch Voraussetzung für die Bearbeitung von Detailthemen, da hier Aufgabenstellungen, Schwerpunktsetzungen und Methoden definiert werden

Peptide‐mediated surface coatings for the release of wound‐healing cytokines

Supporting the wound healing process by sending the appropriate cytokine signals can shorten healing time and overcome chronic inflammation syndromes. Even though adhesion peptides consisting of Arg-Gly-Asp (RGD) are commonly used to enhance cell-surface interactions, peptide-mediated cytokine delivery has not been widely exploited so far. Cytokines interact with high affinity with their cognitive receptors but also with sulfated glycosaminoglycans (GAGs), both of which form a base for incorporation of cytokines into functional biomaterials. Here, we report on a mussel-derived surface coating as a prospective cytokine delivery system using covalently bound heparin mimetics, receptor-derived chemokine-binding peptides, and heparin-binding peptides (HBP). The latter enabled non-covalent immobilization of heparin on the surface followed by chemokine binding and release, whereas the former allowed direct non-covalent chemokine immobilization. The peptide displayed excellent binding to custom-made polystyrene 96-well plates, enabling convenient testing of several compounds. Released chemokine successfully induced migration in Jurkat cells, especially for the non-covalent heparin immobilization approach using HBPs as evaluated in a transwell assay. In comparison, heparin-mimetic coatings, comprised of sulfated peptides and GAG derivatives, proved less efficient with respect to amount of immobilized chemokine and migratory response. Thus, our study provides a roadmap for further rational optimization and translation into clinics

Motivation and active travel in adolescent girls and boys in Germany – Findings from the ARRIVE study

Active travel (using an active mode of transport such as walking or cycling) contributes to the accumulation of daily physical activity and thus holds potential for promoting health. To promote active travel among adolescents an in-depth understanding of determinants from a sex/gender perspective is needed. Within Self-Determination Theory (SDT), it is proposed that the quality of an individuals’ motivation (i.e., the degree to which it is autonomous) determines the extent to which they engage in particular behaviors and perform them effectively. As part of the ARRIVE study, the aim of this research was to investigate the relationship between motivation and active travel in adolescent boys (N = 263, Mage = 12.92) and girls (N = 254, Mage = 13.21) from a nationwide German sample. Results showed significant group differences between male and female adolescents in the proportion of trips traveled actively, intrinsic motivation and amotivation. Logistic regression analyses demonstrated different relationships of the different types of motivation proposed within SDT on active travel behavior depending on sex/gender. In the total sample, integrated and identified regulation increased the odds of active travel (by 15.8 %, and 20.3 % respectively), whereas amotivation decreased the odds by 23.0 %. Intrinsic motivation and controlled forms of extrinsic motivation (i.e. introjected and external regulation) did not significantly change the odds of active travel. Separate sex/gender-specific analyses were conducted. For boys, only identified regulation significantly increased the odds of active travel (by 40.2 %) and amotivation significantly decreased the odds (by 18.8 %). In girls, integrated (by 25.3 %) and external (by 20.3 %) regulation significantly increased the odds of active travel, while amotivation (26.6 %) significantly decreased the odds. We conclude that disparities exist in the relationship among different regulation types with active travel behavior between adolescent boys and girls, and that findings contradictory to SDT might result from the specific context of traveling to a destination. Considering the regression analyses findings, future interventions to promote active travel among adolescents should incorporate sex/gender-sensitive development, because some behavioral regulations might not be equally effective among girls and boys

Hydrogel patterns in microfluidic devices by do-it-yourself UV-photolithography suitable for very large-scale integration

The interest in large-scale integrated (LSI) microfluidic systems that perform highthroughput biological and chemical laboratory investigations on a single chip is steadily growing. Such highly integrated Labs-on-a-Chip (LoC) provide fast analysis, high functionality, outstanding reproducibility at low cost per sample, and small demand of reagents. One LoC platform technology capable of LSI relies on specific intrinsically active polymers, the so-called stimuli-responsive hydrogels. Analogous to microelectronics, the active components of the chips can be realized by photolithographic micro-patterning of functional layers. The miniaturization potential and the integration degree of the microfluidic circuits depend on the capability of the photolithographic process to pattern hydrogel layers with high resolution, and they typically require expensive cleanroom equipment. Here, we propose, compare, and discuss a cost-efficient do-it-yourself (DIY) photolithographic set-up suitable to micro-pattern hydrogel-layers with a resolution as needed for very large-scale integrated (VLSI) microfluidics. The achievable structure dimensions are in the lower micrometer scale, down to a feature size of 20 µm with aspect ratios of 1:5 and maximum integration densities of 20,000 hydrogel patterns per cm. Furthermore, we demonstrate the effects of miniaturization on the efficiency of a hydrogel-based microreactor system by increasing the surface area to volume (SA:V) ratio of integrated bioactive hydrogels. We then determine and discuss a correlation between ultraviolet (UV) exposure time, cross-linking density of polymers, and the degree of immobilization of bioactive components. © 2020 by the authors