Molecular coupling of light with plasmonic waveguides

We use molecules to couple light into and out of microscale plasmonic waveguides. Energy transfer, mediated by surface plasmons, from donor molecules to acceptor molecules over ten micrometer distances is demonstrated. Also surface plasmon coupled emission from the donor molecules is observed at similar distances away from the excitation spot. The lithographic fabrication method we use for positioning the dye molecules allows scaling to nanometer dimensions. The use of molecules as couplers between far-field and near-field light offers the advantages that no special excitation geometry is needed, any light source can be used to excite plasmons and the excitation can be localized below the diffraction limit. Moreover, the use of molecules has the potential for integration with molecular electronics and for the use of molecular self-assembly in fabrication. Our results constitute a proof-of-principle demonstration of a plasmonic waveguide where signal in- and outcoupling is done by molecules.Comment: 9 pages, 5 figure

Vacuum Rabi splitting and strong coupling dynamics for surface plasmon polaritons and Rhodamine 6G molecules

We report on strong coupling between surface plasmon polaritons (SPP) and Rhodamine 6G (R6G) molecules, with double vacuum Rabi splitting energies up to 230 and 110 meV. In addition, we demonstrate the emission of all three energy branches of the strongly coupled SPP-exciton hybrid system, revealing features of system dynamics that are not visible in conventional reflectometry. Finally, in analogy to tunable-Q microcavities, we show that the Rabi splitting can be controlled by adjusting the interaction time between waveguided SPPs and R6G deposited on top of the waveguide. The interaction time can be controlled with sub-fs precision by adjusting the length of the R6G area with standard lithography methods.Comment: 4 pages, 4 figure

Prevalence of genetically similar Flavobacterium columnare phages across aquaculture environments reveals a strong potential for pathogen control

Intensive aquaculture conditions expose fish to bacterial infections, leading to significant financial losses, extensive antibiotic use and risk of antibiotic resistance in target bacteria. Flavobacterium columnare causes columnaris disease in aquaculture worldwide. To develop a bacteriophage-based control of columnaris disease, we isolated and characterized 126 F. columnare strains and 63 phages against F. columnare from Finland and Sweden in 2017. Bacterial isolates were virulent on rainbow trout (Oncorhynchus mykiss) and fell into four previously described genetic groups A, C, E and G, with genetic groups C and E being the most virulent. Phage host range studied against a collection of 227 bacterial isolates (from 2013 to 2017) demonstrated modular infection patterns based on host genetic group. Phages infected contemporary and previously isolated bacterial hosts, but bacteria isolated most recently were generally resistant to previously isolated phages. Despite large differences in geographical origin, isolation year or host range of the phages, whole-genome sequencing of 56 phages showed high level of genetic similarity to previously isolated F. columnare phages (Ficleduovirus, Myoviridae). Altogether, this phage collection demonstrates a potential for use in phage therapy.Peer reviewe

Users and non-users of web-based health advice service among Finnish university students – chronic conditions and self-reported health status (a cross-sectional study)

<p>Abstract</p> <p>Background</p> <p>The Internet is increasingly used by citizens as source of health information. Young, highly educated adults use the Internet frequently to search for health-related information. Our study explores whether reported chronic conditions or self-reported health status differed among Finnish university students using the Finnish Student Health Services web-based health advice service compared with those not using the service.</p> <p>Methods</p> <p>Cross-sectional study performed by a national postal survey in 2004. Material: A random sample (n = 5 030) of a population of 101 805 undergraduate Finnish university students aged 19–35. The response rate: 63% (n = 3 153). Main outcome measures: Proportion of university students reporting use a of web-based health advice service, diagnosed chronic conditions, and self-reported health status of users and non-users of a web-based health advice service. Statistical methods: Data were presented with frequency distributions and cross-tabulations and the χ²test was used.</p> <p>Results</p> <p>12% (n = 370) of Finnish undergraduate students had used the web-based health advice service and were identified as 'users'. The proportion of male students reporting allergic rhinitis or conjunctivitis was greater among users than non-users (24%, n = 22 vs. 15%, n = 154, χ², P = .03). The proportion of female students reporting chronic mental health problems was greater among users than non-users (12%, n = 34 vs. 8%, n = 140, χ², P = .03). There was no statistical significance between the group differences of male or female users and non-users in self-reported health status (good or fairly good, average, rather poor or poor).</p> <p>Conclusion</p> <p>Among young, highly educated adults the use of a web-based health advice service is not associated with self-reported health status. However, a web-based health advice service could offer support for managing several specific chronic conditions. More research data is needed to evaluate the role of web-based health advice services that supplement traditional forms of health services.</p

Korkeakouluopiskelijoiden terveyskäyttäytyminen ja sosiaaliset suhteet : Tutkimus turkulaisista ensimmäisen vuoden opiskelijoista

Onko "iloinen opiskelijaelämä" terveellistä? Tutkimuksessa tarkasteltiin sosiaalisten suhteiden ja terveyskäyttäytymisen suhdetta turkulaisilla ensimmäisen vuoden opiskelijoilla. Terveyskäyttäytymistä tutkittiin selvittämällä toisaalta opiskelijoiden liikunta- ja ruokatottumuksia sekä hampaiden hoitoa ja suhtautumista liikenneturvallisuuteen ja toisaalta tupakointia sekä alkoholin ja huumeiden käyttöä. Sosiaalisia verkostoja selvitettiin tiedustelemalla mm. ystäväpiirin kokoa, ystävien tapaamistaajuutta sekä aktiivisuutta osallistua yhdistystoimintaan.9,60 euro

Korkeakouluopiskelijoiden terveystutkimus 2000

Tutkimuksessa selvitettiin Ylioppilaiden terveydenhoitosäätiön (YTHS) piirissä olevien korkeakouluopiskelijoiden 1) fyysistä, psyykkistä ja sosiaalista terveydentilaa lääkärin toteamien sairauksien, koetun terveydentilan, oireilun ja mielenterveyttä kartoittavien kysymyssarjojen avulla, 2) keskeisiä terveyskäyttäytymisen piirteitä, tupakointia, alkoholin ja huumeiden käyttöä, ruoka- ja liikuntatottumuksia, liikenneturvallisuuskäyttäytymistä ja hampaiden hoitoa, 3) terveyteen ja terveyskäyttäytymiseen liittyviä tekijöitä, kuten sosiaalisia suhteita, opiskeluun, toimeentuloon ja asumiseen liittyviä kysymyksiä, 4) terveyteen liittyviä asenteita ja terveystiedon lähteitä sekä 5) terveyspalvelujen käyttöä ja mielipiteitä palvelujen laadusta. Tutkimuksen kohdejoukkona olivat alle 35-vuotiaat, perustutkintoa suorittavat suomalaiset opiskelijat. Otoksen koko oli 5 030 opiskelijaa; otoksesta 46,1 % oli miehiä ja 53,9 % naisia. Tutkimus suoritettiin postitse lomakekyselynä, ja uusintakyselyjä tehtiin kolme. Tutkimuksen vastausprosentiksi tuli 63,1 %. Tulokset raportoitiin yksittäisten kysymysten tai kysymyssarjoista muodostettujen mittareiden ristiintaulukoinnein sukupuolittain, ikäryhmittäin sekä opiskelun keston, opiskelupaikan ja opiskelualan mukaan.9,60 euro