Lakes and seas of Titan

Abstract. This thesis reviews studies about the lakes and seas of Saturn’s moon, Titan. Conditions on Titan’s surface are first estimated to validate that substances in Titan’s atmosphere can exist in liquid phase. This is followed by descriptions of devices that have been used to study Titan from Earth, space and on its surface. Research concerning the detection and distribution of the lakes are then discussed. Features of the lakes such as surface areas, chemical compositions and formations like shores are looked into. Results from models that describe liquid currents driven by tidal forces, wind, temperature differences and rain induced density differences are given. This leads into discussion of liquid surface waves. Titan’s potential for supporting life is also considered. Observation of a disappearing and reappearing region in Titan’s sea, the Magic Island phenomenon, is construed and possible causes for this phenomenon are examined. Lastly, future mission projects that are capable of studying the lakes in situ are described with the emphasis on the Titan Submarine project

Investigation of two cataclysmic variables EG Cnc and OT J210950.5+134840

Abstract. This study focuses on the interacting binary star systems, cataclysmic variables, where a white dwarf accretes matter through the inner Lagrangian point from its companion star. Many of these objects contain an accretion disc, where matter accumulates before falling on the surface of the primary. The mass loss and angular momentum loss lead to the system evolving, with the period decreasing and the secondary degenerating into a substellar brown dwarf stage. As a result, the period evolution reverses, and the system is classified as a period bouncer. For this study, two objects named EG Cnc and OT J210950.5+134840 were studied to obtain systemic parameters and traces of the secondary type. This was done with spectroscopic and photometric data obtained with many telescopes and instruments, such as ESO VLT (X-shooter) and NOT (ALFOSC and NOTCam). Methods of analysis included time series analysis, radial velocity analysis, spectral energy distribution analysis, Doppler tomography and fitting of white dwarf atmosphere models. It is found that EG Cnc is a period bouncer, as it contains a brown dwarf secondary of mass M2 = 0.045(5) M⊙. The secondary of OT J210950.5+134840 is a low-mass star with a mass of M2 = 0.085–0.108 M⊙. Therefore, this object is still evolving towards the period minimum.Kahden kataklysmisen muuttujan EG Cnc:n ja OT J210950.5+134840:n tutkimus. Tiivistelmä. Kataklysmiset muuttujat ovat valkoisesta kääpiöstä sekä kevyemmästä seuralaistähdestä koostuvia vuorovaikuttavia kaksoistähtiä. Monissa näissä järjestelmissä seuralaistähti menettää pintakerroksensa ainetta valkoista kääpiötä ympäröivään kertymäkiekkoon, josta aine putoaa kohti valkoisen kääpiön pintaa. Seuralaistähden kulmaliikemäärän tulee vähentyä, jotta massan menetys voi jatkua vakaana, johtaen järjestelmän periodin lyhenemiseen. Periodin lyheneminen jatkuu, kunnes seuralaistähti kehittyy massan menetyksen seurauksena ruskeaksi kääpiöksi, joka johtaa järjestelmän periodin pitenemiseen. Määrittämällä järjestelmän parametrit, kuten periodi ja tähtien massat, voidaan periodiminiä kohti kehittyvät ja siitä etääntyvät kohteet erottaa toisistaan. Työssä selvitettiin kahden kataklysmisen muuttujan EG Cnc:n ja OT J210950.5+134840:n järjestelmäparametrit, sekä arvioitiin näiden kohteiden seuralaistähtien evolutionääriset vaiheet. Tutkimusaineisto koostui spektroskooppisista ja fotometrisistä mittauksista, jotka toteutettiin käyttäen muun muassa ESO VLT:n X-shooter-instrumenttia sekä NOT:n ALFOSC- ja NOTCam-instrumentteja. Analyysimenetelmät koostuivat aikasarja-analyysista, säteisnopeusanalyysista, spektrien energiajakaumien arvioinnista, Doppler-tomografiasta sekä valkoisen kääpiön kaasukehämallien sovittamisesta. Järjestelmäparametrien sekä analyysimetodien perusteella EG Cnc on niin sanottu ”period-bouncer”, eli järjestelmän seuralaistähti on kehittynyt ruskeaksi kääpiöksi ja järjestelmän periodi pitenee. OT J210950.5+145840:n seuralaistähti ei ole vielä kehittynyt ruskeaksi kääpiöksi, ja järjestelmän kiertoaika lyhenee

Playful approaches to news engagement

From crossword puzzles and quizzes to more complex gamification strategies and serious newsgames, legacy media has long explored ways to deploy playful approaches to deliver their content and engage with the audience. We examine how news and games fit together when news organizations, game creators and news audiences welcome gameful forms of communication and participation. Moreover, we reflect on the theoretical and empirical significance of merging news with games as a way to reformulate normative assumptions, production practices and consumption patterns. As a result, the boundaries between journalism and game’s logics start to erode, and they begin to find new ways of converging

Laboratory course on Streptomyces genetics and secondary metabolism

The "Streptomyces genetics and secondary metabolism" laboratory course gives an introduction to the versatile soil dwelling Gram-positive bacteria Streptomyces and their secondary metabolism. The course combines genetic modification of Streptomyces; growing of the strain and protoplast preparation, plasmid isolation by alkaline lysis and phenol precipitation, digestions, and ligations prior to protoplast transformation, as well as investigating the secondary metabolites produced by the strains. Thus, the course is a combination of microbiology, molecular biology, and chemistry. After the course the students should understand the relationship between genes, proteins, and the produced metabolites. 2016 by The International Union of Biochemistry and Molecular Biology, 44(5):492-499, 2016. 2016 The International Union of Biochemistry and Molecular Biology.</p

Performance and flow dynamics studies of polymeric optofluidic sers sensors

We present a polymer-based optofluidic surface enhanced Raman scattering chip for biomolecule detection, serving as a disposable sensorchoice with cost-effective production. The SERS substrate is fabricated by using industrial roll-to-roll UV-nanoimprinting equipment andintegrated with adhesive-based polymeric microfluidics. The functioning of the SERS detection on-chip is confirmed and the effect of thepolymer lid on the obtainable Raman spectra is analysed. Rhodamine 6G is used as a model analyte to demonstrate continuous flowmeasurements on a planar SERS substrate in a microchannel. The relation between the temporal response of the sensors and sample flowdynamics is studied with varied flow velocities, using SERS and fluorescence detection. The response time of the surface-dependent SERSsignal is longer than the response time of the fluorescence signal of the bulk flow. This observation revealed the effect of convection on thetemporal SERS responses at 25 μl/min to 1000 μl/min flow velocities. The diffusion of analyte molecules from the bulk concentration intothe sensing surface induces about a 40-second lag time in the SERS detection. This lag time, and its rising trend with slower flow velocities, has to be taken into account in future trials of the optofluidic SERS sensor, with active analyte binding on the sensing surface

Sporadic human Yersinia enterocolitica infections caused by serotype 4/O:3 originate mainly from pigs

Yersinia enterocolitica 4/O : 3 is the most frequent cause of sporadic human yersiniosis in Finland and Germany. To investigate the possible link between pigs and humans, 282 human and 534 porcine strains from Finland and Germany were characterized with PFGE using NotI, ApaI and XhoI enzymes. Most of the human strains (>80 %) were indistinguishable from the porcine strains in both countries and most of the genotypes (178/182) were different in Finland and Germany. The indistinguishable genotypes among human and porcine strains together with different genotypes in Finland and Germany indicate that pigs are an important source of sporadic yersiniosis in both countries

Listeria monocytogenes isolates from invasive infections : variation of sero- and genotypes during an 11-year period in Finland.

Listeria monocytogenes strains that were isolated from 314 human listeriosis cases in Finland during an 11-year period were analyzed by O:H serotyping and pulsed-field gel electrophoresis (PFGE). Serotyping divided the isolates into five serotypes, the most common being 1/2a (53%) and 4b (27%). During the study period, the number of cases caused by serotype 1/2a increased from 22% in 1990 to 67% in 2001, and those caused by serotype 4b decreased from 61 to 27%, respectively. PFGE with restriction enzyme AscI divided the strains into 81 PFGE genotypes; among strains of serotypes 1/2a and 4b, 49 and 18 PFGE types were seen, respectively. PFGE type 1 (serotype 1/2a) was the most prevalent single type (37 strains). Together with six other, closely related PFGE types, PFGE type 1 formed a group of 71 strains, representing 23% of all 314 strains. Strains of PFGE type 1 have also been isolated from cold smoked fish, suggesting a source of human infections caused by this type. Moreover, PFGE type 24 (serotype 1/2c) was significantly associated with gender: 5% of 180 male subjects but none of 132 female subjects (P = 0.012). An electronic database library was created from the PFGE profiles to make possible the prompt detection of new emerging profiles and the tracing of potential infection clusters in the future