Mirror-Coupled Nanoantennas with Hexagonal-Boron Nitride Spacers

Transparent dielectric materials are employed in a wide range of optical resonators. Combining plasmonic nanoantennas with such resonators enables the formation of nanoscale optical resonances. The novel nano-optics observed by combining these heterostructures with optically active media is laying the foundations for devices such as ultra-high efficiency optical switches. In this thesis, mirror-coupled nanoantennas consisting of the layered dielectric hexagonal-Boron Nitride encapsulated between gold nanoparticles and a gold substrate, are probed using high-angle optical scattering measurements. During illumination of individual nanoparticles, light is trapped at the nanoscale inside the hBN, between particle and gold beneath. As the thickness of hBN is decreased, the coupling between nanoparticle and substrate changes dramatically. Here, the inert properties of hBN are used to remove extraneous influences on scattering spectra, thereby revealing new nanoscale light confinement mechanisms and sub-nanometre structural changes. In the first experiment presented, submicron-thick hBN crystals embedded in gold form planar Fabry-Perot half-microcavities. Gold nanoparticles on top of these microcavities form previously unidentified angle- and polarization-sensitive nanoresonator modes that are tightly laterally confined by the nanoparticle. Comparing dark-field scattering with reflection spectroscopies shows plasmonic and Fabry-Perot-like enhancements magnify subtle interference contributions, which lead to unexpected redshifts in the dark-field spectra, explained by the presence of these new modes. In the second experiment presented, the thickness of hBN is reduced down to a singleatom- thick layer leading to greatly enhanced field intensities and confinement when compared to thicker layers, via plasmonic coupling. By comparing results to an analytic model, resultant ultra-sensitive scattering signals from nanoparticles atop these thinner layers reveal field interactions sub-nanometre structural changes. Finally, photoluminescence measurements on defects in as-grown monolayer WS2 on gold lead to clear emission despite significant substrate quenching. Measurements using nanoplatelets of the metal halide perovskite methyl-ammonium lead-iodide, lead to suppression of resonant modes and a blue-shifting behaviour correlated with light emission

Analysis of the Rubbing Behaviour of Psammophiids : A Methodological Approach

Several snakes belonging to the eight genera of the family Psammophiidae are the sole known snakes to smear the secretion of their nasal gland on their own belly and flanks by little rapid head movements. The main objective of the present study is to determine behaviourally the function of this “rubbing behaviour”. The rubbing behaviour itself and its possible functions have been mentioned several times in literature, but most of them without specific experimental analysis. This is the first behavioural study focussing on the rubbing behaviour of psammophiids in order to examine its function with more clarity. Psammophiids belonging to the four genera Malpolon, Psammophis, Psammophylax and Scutophis were studied. Since it had been stated that snakes have pores on their scales allowing the passage of lipids through the skin to protect it against desiccation, it was important to verify this feature in psammophiids. The scanning electron microscopic analysis of the dorsal scale ultrastructure of several psammophiids and control species was undertaken: the results showed that neither psammophiids, nor control taxa have pores on their scale surface. Some years ago, the nasal gland secretion of Malpolon monspessulanus, a psammophiid known to do rubbing behaviour, had been analysed. This analysis showed the presence of lipids, known to protect the skin against desiccation. Since other species of psammophiids also perform rubbing behaviour, it was verified whether their nasal secretion also contains lipids. The presence of lipids in the nasal gland secretion of Psammophis mossambicus and Scutophis moilensis could only be presumed by gas chromatographic analysis. But it has to be assumed that these species also have a lipid-rich nasal secretion since they also perform rubbing behaviour -as Malpolon monspessulanus. One hypothesis on the function of rubbing behaviour is that it serves to mark an unknown environment. To verify this, the snakes were place into a terrarium unknown to the snakes: The frequency of its rubbing behaviour on the first day was compared to the mean frequency of rubbing of the following days. If the rubbing behaviour serves to mark, its frequency would be more elevated on the first day. This frequency was however not significantly higher, so that rubbing behaviour cannot be considered as marking behaviour. In a further experiment, it was tested whether nasal secretion is used to leave an informative trail to conspecifics. Two couples of Psammophis mossambicus and Scutophis moilensis were studied. The snakes were place one by one into a terrarium. No changes in behaviour (e.g. elevated tongue flicking) could be detected in the snakes placed at second in the terrarium, regardless of their sex of the sex of the snake introduced at first. Finally, in order to determine whether rubbing behaviour depends on external factors, temperature was varied in an experimental setup. There was a significant correlation between increasing temperature and the number of rubbing behaviour in all psammophiids studied. This states the hypothesis that rubbing behaviour is primarily dependent on external factors and that it is used to avoid the desiccation. This is done by thanks of the nasal secretion known to be lipid-rich as in Malpolon monspessulanus and it has then to be considered that this secretion is also lipid-rich in the other psammophiid species since their number of rubbing behaviour also increased with temperature. This allows these snakes to be active even in the hottest hours of the day, e.g. minimising concurrence with other predators. Additionally to the behavioural experiments, for the first time the rubbing behaviour of the genus Rhamphiophis could be verified in R. rubropunctatus and R. rostratus. This elevates the number of genera performing rubbing behaviour on seven, of the eight comprised in this family. The “last” genus in which rubbing behaviour has not been recorded yet is Dipsina. The rubbing behaviour could additionally be documented for a further Psammophis species, P. elegans and for a further Psammophylax species, P. acutus acutus. A further morphological analysis should confirm the affiliation of the species moilensis to its own genus. It had been affiliated long time to the genus Malpolon. Its attribution to its own genus, Scutophis, had been proposed but not unanimously adopted in the literature. The affiliation was primarily based on the ability of moilensis to spread the neck when threatened -Malpolon species are unable to do this. The comparative morphological analysis between the neck ribs of Malpolon monspessulanus and Scutophis moilensis confirmed differences at the level of the length of these ribs, those in S. moilensis being obviously longer. This difference reinforces the affiliation of both species to different genera

The National Institute for Health Research Service Delivery and Organisation Network: a descriptive narrative of the network

BACKGROUND: Governments from the 1990s have demonstrated a concern with bridging the gaps between biomedical, clinical and health services research (HSR), in particular with bringing the benefits of that research into practice. To address this concern, the National Coordinating Centre for NHS Service Delivery and Organisation Research and Development commissioned a network in 2007 for a period of 5 years to support NHS managers in accessing and engaging with HSR generally and specifically with their research portfolio. OBJECTIVES: The Service Delivery and Organisation (SDO) Network, hosted by the NHS Confederation, aimed to enable managers to improve and develop services by facilitating their access to the latest HSR. Through a combination of push, pull, and linkage and exchange strategies, the network proactively targeted interventions at senior, middle and new managers. METHODS: This report presents a descriptive narrative of the SDO Network building in the political and organisational contexts. Information contained in this report was obtained from informal discussions with the network team, document review, analysis of web content and a review of relevant academic and grey literature. Discussions with former and current SDO Network members of staff helped to capture perceptions of influence and working practices, and suggest significant/high-impact interventions. RESULTS: The evolution of the SDO Network is captured in four distinct phases of development: initiation of the SDO Network project and its place within a new NHS research and development infrastructure; a period of knowledge transfer and exchange to encourage interactions across interest groups and collaboration with other networks; then a period of increasing complexity and consolidation from research translation to capacity building; and finally the end of project and the new innovation landscape phase. CONCLUSION: Lessons for similar initiatives aimed at knowledge mobilisation in the health sector include ensuring an adequate evaluation framework is in place from initiation, to capture impact and inform strategy, and developing a range of collaborative relationships to expand the scope and reach of activities. Future work could compare or contrast the experience of the SDO Network with studies of other networks in health (nationally or internationally) to address its contribution within the wider research literature in this field. FUNDING: The Health Services and Delivery Research programme

Qu’en est-­il de la fertilité dans le syndrome de Turner ?

Introduction : Le syndrome de Turner est une affection génétique rare, affectant un nouveau-­ né sur 2500 de sexe féminin, lié à une perte totale ou partielle d’un des deux chromosomes X. Les deux caractéristiques phénotypiques les plus fréquentes sont une petite taille et une insuffisance ovarienne qui est responsable du retard pubertaire et d’une infertilité dans la majorité des cas. Environ 30% des patientes développeront une puberté spontanée et seules 2 à 5% auront des cycles réguliers pouvant mener à une grossesse spontanée (1). Le risque d’infertilité est l’une des principales préoccupations pour ces patientes. Les techniques de procréation médicalement assistée permettent aujourd’hui dans quelques cas de préserver leur fertilité. Objectifs : Le but premier de ce master était d’établir un bilan de la situation actuelle des patientes ayant été suivies à Lausanne, avec un intérêt particulier pour le développement pubertaire et leur potentiel de fertilité. Un deuxième but était de créer une brochure explicative au sujet de la fertilité chez les patientes porteuses du syndrome de Turner. Méthode : Pour le premier objectif, une étude rétrospective portant sur toutes les patientes suivies pour un syndrome de Turner dans l’unité d’endocrinologie pédiatrique à Lausanne entre 1998 et 2017 a été menée. Des statistiques descriptives ont été utilisées pour présenter les résultats, et les données ont été comparées avec celles de la littérature. Une revue de cette dernière a été effectuée pour créer la brochure explicative destinée aux patientes et à leur entourage. Celle-­ci est axée sur les diverses possibilités de préservation de la fertilité, ainsi que les risques liés à une éventuelle grossesse. Résultats : Parmi la cohorte de 57 patientes, 10 sont encore trop jeunes pour avoir présenté une ménarche spontanée (dont 9 également trop jeunes pour la puberté). 25/48 (52%) patientes ont présenté une puberté spontanée et 18/47 (38%) ont présenté une ménarche spontanée. Trois patientes porteuses du caryotype (45,X) ont développé une puberté spontanée, mais une seule d’entre elles a développé une ménarche spontanée. Après examen des résultats des dosages hormonaux (FSH, AMH, inhibine B) chez les patientes qui ont présenté une puberté spontanée suivie d’une ménarche spontanée, 6/18 (33%) patientes présentent un profil favorable pour une fertilité potentielle, 4/6 n’ont pas d’atteinte cardiaque. Ces 4 patientes sont porteuses d’une forme mosaïque. 10/47 patientes en âge d’avoir développé une ménarche montrent une insuffisance ovarienne probable. Il y a 27/57 (47%) patientes qui ne sont porteuses d’aucune malformation cardiaque. Discussion : Seules 4/47 (9%) des patientes en âge d’avoir développé une ménarche présentent un potentiel de fertilité et n’ont pas de contre-­indication à une grossesse ;; elles pourraient, en cas d’absence de grossesse spontanée, être concernées par une stimulation ovarienne suivie d’une FIV. Pour les 41 autres patientes, le don d’ovocytes serait une possibilité pour celles n’ayant pas de contre-­indication à une grossesse. Pour les autres, il reste néanmoins la possibilité de l’adoption. On observe une augmentation du potentiel de fertilité, liée à un plus grand nombre de formes moins sévères du syndrome. Davantage d’interruptions volontaires de grossesse ont lieu pour les formes les plus graves, grâce aux progrès du dépistage prénatal. Nous avons observé que 3 patientes porteuses d’un caryotype (45,X) ont présenté une puberté spontanée, mais avec un profil de fertilité peu probable au dernier contrôle. On peut se demander si une intervention plus précoce pourrait préserver la fertilité chez ces patientes. Conclusion : Le nombre de patientes ayant présenté une puberté spontanée est plus élevé que celui mentionné dans la littérature, du fait entre autres d’un nombre de mosaïsme plus important que par le passé. L’étude a mis en évidence un suivi des patientes lacunaire quant à l’évaluation de la fertilité et la fonction ovarienne dès la naissance. Une meilleure information des patientes et de leur entourage est un premier pas afin d’améliorer cette prise en charge

Die Goldbüste des Septimius Severus: Gold- und Silberbüsten römischer Kaiser

Die Goldbüste des Kaisers Septimius Severus (193–211 n. Chr.) wurde im Jahr 1965 in Didymoteicho, dem antiken Plotinopolis (Nordgriechenland) gefunden. Dieser überaus seltene Fund hochstehender Goldschmiedearbeit liegt erstmals ausführlich untersucht und bebildert vor. Es handelt sich um die eine von nur zwei erhaltenen größeren Goldbüsten römischer Kaiser; das zweite, leicht unterlebensgroße Exemplar ist die Büste von Marc Aurel aus Avenches (Schweiz). Die 28 cm hohe Goldbüste des Septimius Severus wiegt knapp drei römische Pfund (980 g) und entspricht somit einem vielfach für solche Objekte verwendeten Gewichtsmodul. Goldporträts waren dem Kaiser vorbehalten. Als portable Bildnisse konnten sie den Kaiser bei offiziellen Handlungen wie am Gericht vertreten, sie dienten aber auch im Kaiserkult sowie in der römischen Armee, wo sie an der Spitze von Standarten mitgetragen wurden. Mit Beiträgen von Alessandra Giumlia-Mair Fotos der Goldbüste des Septimius Severus von Thanos Kartsoglo

Scaling photosynthesis and water use from leaves to paddocks

Plant breeders can select cultivars with physiological traits that confer a growth or yield advantage to individual plants. The extent to which single plant characters influence canopy performance depends on interactions between vegetation and the atmosphere and the non-linear response of physiological processes to the environment. Better understanding of the scaling of photosynthesis and water use will allow the assessment of changes to leaf scale physiological traits at the canopy scale and prediction of the response of vegetation to climate change. This thesis examines the relationship between reduced stomatal conductance and canopy scale water-use efficiency (ratio of instantaneous net canopy photosynthesis to total canopy evaporation). A multi-disciplinary research project was established with two large paddocks of wheat with cultivars of contrasting leaf-scale water-use efficiency, due to inherent differences in stomatal conductance. Intensive measurements were made of C02 and H20 fluxes at leaf and canopy scales. Different stomatal conductances at the leaf scale were reflected at the. canopy scale, although their effects on transpiration were reduced due to canopy boundary layers and soil evaporation. Comparison of scaling from leaf to canopy in the two crops was complicated by their different leaf area indices. To facilitate scaling from leaves to canopies, models of stomatal conductance, leaf photosynthesis and radiation penetration in canopies were used. A comparison of several models of conductance with field data found that using the correlation of conductance with photosynthesis was the best approach. The same model was found to work equally well at the canopy scale, using parameters derived from leaf scale data. Canopy photosynthesis was modelled with a biochemical model of leaf photosynthesis incorporated into different integration schemes. A canopy model which divided the canopy into a single layer of sunlit and shaded leaves was found to be as accurate as a multi-layer model, but simpler and allowed incorporation of within-canopy profiles of photosynthetic capacity. A big-leaf model of canopy photosynthesis was found acceptable if tuned, but the uncertainties increased when it was used to predict responses of canopies with different properties. Photosynthetic capacity, the main parameter of the canopy photosynthesis model, was found to decrease during the day under conditions of mild water stress at both the leaf and canopy scale. Combined models of photosynthesis, conductance and energy balance accurately described diurnal variation of canopy gas exchange. The model predicted that a 40% reduction in stomatal conductance would result in 36% greater leaf transpiration efficiency and 19% greater canopy transpiration efficiency (ratio of gross canopy photosynthesis to canopy transpiration) which compared favourably with field measurements, but depended on the magnitude of the conductance and wind speed. Measurements of air temperature, humidity and surface temperature along a transect across the interface between the two crops with different evaporation rates, showed that advection did occur, but that it had minimal impact on canopy fluxes. It was concluded that reduced stomatal conductance does result in reduced transpiration and better transpiration efficiency at the canopy scale, but that canopy boundary layers and greater soil evaporation reduce the benefit. In this case reduced conductance was also accompanied by greater yield, although this result depends on the availability of soil water. The models presented were an effective tool for scaling nonlinear physiological processes from leaves to canopies and provide a useful framework for assessing the impact of climate change on vegetation

NHS top managers, knowledge exchange and leadership: the early development of Academic Health Science Networks – a mixed-methods study

This study explored knowledge networking and leadership in the context of the early development of Academic Health Science Networks in England and made recommendations for future research

Variation in survival after diagnosis of breast cancer in Switzerland

Background: Survival after diagnosis of cancer is a key criterion for cancer control. Major survival differences between time periods and countries have been reported by the EUROCARE studies. We investigated whether similar differences by period and region existed in Switzerland. Methods: Survival of 11 376 cases of primary invasive female breast cancer diagnosed between 1988 and 1997 and registered in seven Swiss cancer registries covering a population of 3.5 million was analysed. Results: Comparing the two periods 1988-1992 and 1993-1997, age-standardized 5 year relative survival improved globally from 77% to 81%. Furthermore, multivariate analysis adjusting for age, tumour size and nodal involvement identified regional survival differences. Survival was lowest in the rural parts of German-speaking eastern Switzerland and highest in urbanised regions of the Latin- and German-speaking northwestern parts of the country. Conclusions: This study confirms that survival differences are present even in a small and affluent, but culturally diverse, country like Switzerland, raising the issue of heterogeneity in access to care and quality of treatmen