17 research outputs found
Erste klinische Erfahrungen mit einem konfokal arbeitenden Instrument zur Quantifizierung von LinsentrĂĽbungen
Zielsetzung: Die vorliegende Studie sollte zeigen, wie sich gesunde Augenlinsen und Linsen mit klinisch manifesten TrĂĽbungen im Densitogramm des Confocal-Opacity-Meters (COM 2000) darstellen.
Methodik: Untersucht wurden 125 Augen von 72 Probanden im Alter von 8 bis 88 Jahren. Ausgewählt wurden nicht voroperierte Augen mittels konventioneller Untersuchung an der Spaltlampe. Hier waren 42 der untersuchten Linsen klar, während 83 Linsen klinisch relevante Trübungen aufwiesen. Zum Vergleich wurden jeweils Scheimpflugaufnahmen mit einer Topcon SL 45b Scheimpflugkamera angefertigt.
Ergebnisse: Die Kornea stellt sich in Scheimpflug- und konfokalen Densitogrammen als Peak dar, an den sich die streulichtarme Vorderkammer anschließt. Der Verlauf von Scheimpflugdensitogrammen der Linse ist bekannt und relativ leicht zu interpretieren. Die Grenzflächen zwischen den anatomischen Linsenstrukturen sind hier selbst bei klaren Linsen durch erhöhte Streuung identifizierbar. Im Gegensatz dazu korrelieren die Strukturen des konfokalen Densitogrammes nur wenig mit dem anatomischen Aufbau der Linse. Relativ sicher zuzuordnen sind jedoch stark ausgeprägte Maxima im Bereich der vorderen bzw. hinteren Kapsel.
Auch bezüglich der klinisch relevanten Linsentrübungen unterscheiden sich Scheimpflug - und konfokale Densitogramme. Im Falle von reifen Katarakten im Bereich des Linsenkernes bestätigen Scheimpflugaufnahmen den aus Spaltlampenuntersuchungen gewonnenen Eindruck eines lokal 'undurchsichtigen' Areals. Demgegenüber ist der Linsenkern für die große Wellenlänge des konfokalen Instrumentes weitgehend transparent und innerhalb des Kernes und auch hinter dem Kern gelegene Strukturen bleiben erkennbar. Kortikale Trübungen manifestieren sich im konfokalen Densitrogramm durch zusätzliche Strukturierung der die Linse begrenzenden Hauptpeaks.
Schlussfolgerung: Einerseits zeigt die komplexe Struktur der mit dem konfokalen Instrument aufgenommenen Densitogramme, dass sie eine Fülle von Informationen enthalten, andererseits sind die Messungen schwer zu interpretieren. Die Maxima der Streulichtintensität reflektieren vermutlich biochemische Vorgänge an Membran-, Enzym- oder Strukturptoteinen der Linse. Es ist denkbar, daß sich hier ganz neue Möglichkeiten biochemische Vorgänge der Linse in vivo zu untersuchen eröffnen.
Es hätte den Rahmen der vorliegenden, orientierenden Studie gesprengt, die molekularen Strukturen zu identifizieren, die für den beobachteten Verlauf der Streulichtintensität verantwortlich sind.
Die Interpretation des Trübungsverlaufes innerhalb der Linse muß deshalb weiterführenden Studien vorbehalten bleiben. Sie haben jedoch nur dann Aussicht auf Erfolg, wenn zuvor technische Verbesserungen an der Kamera vorgenommen werden. Um reproduzierbare Messungen zu ermöglichen, wird eine Justiervorrichtung benötigt, die es erlaubt wiederholt Messungen am selben Ort der Linse durchzuführen. Die Verwendung eines Lasers mit variabler Wellenlänge als Lichtquelle ist Voraussetzung einem Verständnis der beobachteten Streulichtintensitäten näher zu kommen
Active Children Through Individual Vouchers Evaluation: A Mixed-Method RCT
Introduction
Physical activity declines in adolescence, especially among those in deprived areas. Research suggests this may result from accessibility barriers (e.g., cost and locality). The Active Children Through Individual Vouchers Evaluation RCT aimed to improve the fitness and heart health of teenagers in Wales with the help of teenagers who co-produced the study.
Study design
This study was a mixed-method RCT.
Setting/participants
Before data collection, which took place at baseline, 6 months, and 12 months for both arms, 7 schools were randomized by an external statistician (4 intervention schools, n=524; 3 control schools, n=385).
Intervention
The Active Children Through Individual Vouchers Evaluation intervention included provision of activity vouchers (£20 per month), a peer mentoring scheme, and support worker engagement for 12 months between January and December 2017. Data analysis occurred February–April 2018.
Main outcome measures
Data included measures of cardiovascular fitness, cardiovascular health (blood pressure and pulse wave analysis), motivation, and focus groups.
Results
The intervention showed a trend to improve the distance ran (primary outcome) and was significant in improving the likelihood of intervention teenagers being fit (OR=1.21, 95% CI=1.07, 1.38, p=0.002). There was a reduction in teenagers classified as having high blood pressure (secondary outcome) in the intervention group (baseline, 5.3% [28/524]; 12 months, 2.7% [14/524]). Data on where teenagers used vouchers and evidence from focus groups showed that teenagers wanted to access more unstructured, informal, and social activities in their local areas.
Conclusions
Active Children Through Individual Vouchers Evaluation identified methods that may have a positive impact on cardiovascular fitness, cardiovascular health, and perspectives of activity. Consulting with teenagers, empowering them, and providing more local opportunities for them to take part in activities that are fun, unstructured, and social could positively impact teenage physical activity
Predictors of cardiovascular health in teenagers (aged 13–14 years): a cross-sectional study linked with routine data
Objective To examine the predictors of cardiovascular health in teenagers (aged 13–14 years).
Methods Measures of arterial stiffness (augmentation index [AI]), blood pressure and cardiovascular fitness were taken from 234 teenage children (n=152 boys) and subsequently linked to routine data (birth and general practice records, education data and hospital admission data). Deprivation at school and at individual level was measured at birth, at 1 year old, at 13 years old and at secondary school using the Welsh Index of Multiple Deprivation (WIMD) Multivariate regression analysis determined associations between routinely collected data and cardiovascular measures.
Results Teenagers had higher augmentation index (2.41 [95% CI: 1.10 to 3.72]), ran fewer metres (-130.08 metres [95% CI: -234.35 to -25.78]) in the Cooper Run Test if they attended a more deprived school. However, higher individual level deprivation was associated with greater fitness (199.38 metres [95% CI: 83.90 to 314.84]). Higher systolic blood pressure was observed in first born children (10.23 mmHg [95% CI: 1.58 to 18.88]) and in those who were never breastfed (4.77 mmHg [95% CI: 1.10 to 8.42]).
Conclusions Improving heart health in deprived areas requires multi-level action across childhood namely, active play and programmes that promote physical activity and fitness and, the promotion of breastfeeding. Recognition of the important early indicators and determinants of cardiovascular health supports further development of the evidence base to encourage policy-makers to implement preventative measures in young people
What works best when implementing a physical activity intervention for teenagers? Reflections from the ACTIVE Project: a qualitative study
Objective
This paper explores what aspects of a multicomponent intervention were deemed strengths and weaknesses by teenagers and the local council when promoting physical activity to young people.
Design
Qualitative findings at 12 months from a mixed method randomised control trial.
Methods
Active Children Through Incentive Vouchers—Evaluation (ACTIVE) gave teenagers £20 of activity enabling vouchers every month for a year. Peer mentors were also trained and a support worker worked with teenagers to improve knowledge of what was available. Semistructured focus groups took place at 12 months to assess strengths and weaknesses of the intervention. Eight focus groups (n=64 participants) took place with teenagers and one additional focus group was dedicated to the local council’s sport development team (n=8 participants). Thematic analysis was used to analyse the data.
Results
Teenagers used the vouchers on three main activities: trampolining, laser tag or the water park. These appeal to both genders, are social, fun and require no prior skill or training. Choice and financial support for teenagers in deprived areas was considered a strength by teenagers and the local council. Teenagers did not engage with a trained peer mentor but the support worker was considered helpful.
Conclusions
The ACTIVE Project’s delivery had both strengths and weakness that could be used to underpin future physical activity promotion. Future interventions should focus on improving access to low cost, fun, unstructured and social activities rather than structured organised exercise/sport. The lessons learnt from this project can help bridge the gap between what is promoted to teenagers and what they actually want from activity provision
Tumor microenvironment-dependent epigenetic imprinting in the vasculature predicts colon cancer outcome
A model-based early warning system for runoff-generated debris-flow occurrence: Preliminary results
Early warning systems for debris flows are low cost measures for mitigating this kind of hazard. The early warning systems provide a timely alert for upcoming events in order to take protective measures, such as closing railways-roads, evacuating people from the threatened areas, and put rescue forces into readiness. These systems usually are sensor-based, and the alert time is the interval between the timing of the first detachment of debris flow by a sensor and its arrival into the threatened area. At the purpose of increasing the alert time, we propose an early warning system based on a model-cascade: nowcasting, hydrological- and triggering models. Nowcasting anticipates rainfall pattern that is transformed into runoff by the hydrological model. The triggering model estimates the volume of sediments that the runoff can entrain, and compares it with a critical threshold. If this is exceeded the alert is launched. The proposed early warning system is tested against the available data of the Rovina di Cancia (Northeast Italy) site
Das Controllingsystem eines Maschinenbauunternehmens
Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel C 193468 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Improved Circuit Compilation for Hybrid MPC via Compiler Intermediate Representation
Secure multi-party computation (MPC) allows multiple parties to securely evaluate a public function on their private inputs. The field has steadily moved forward and real-world applications have become practical. However, MPC implementations are often hand-built and require cryptographic knowledge. Thus, special compilers like HyCC (BĂĽscher et al., CCS\u2718) have been developed, which automatically compile high-level programs to combinations of Boolean and arithmetic circuits required for mixed-protocol (hybrid) MPC. In this work, we explore the advantages of extending MPC compilers with an intermediate representation (IR) as commonly used in modern compiler infrastructures. For this, we extend HyCC with a graph-based IR that facilitates the implementation of well-known algorithms from compiler design as well as further MPC-specific optimizations. We demonstrate the benefits by implementing arithmetic decomposition based on our new IR that automatically extracts arithmetic expressions and then compiles them into separate circuits. For a line intersection algorithm, we require 40% less run-time and improve total communication by a factor of 3x compared to regular HyCC when securely evaluating the corresponding circuit with the hybrid MPC framework ABY (Demmler et al., NDSS\u2715)