Fermionic decay of a massive scalar in the early Universe

We derive a curved space generalization of a scalar to fermion decay rate with a Yukawa coupling in expanding Friedmann-Robertson-Walker universes. This is done using the full theory of quantum fields in curved spacetime and the added-up transition probability method. It is found that in an expanding universe the usual Minkowskian decay rates are considerably modified for early times. For conformally coupled scalars the decay rate is modified by a positive additive term proportional to the inverse of mass and related to the expansion rate of the Universe. We compare and contrast our results with previous studies on scalar to scalar decay and find that in general the decay channel into fermions is the dominant channel of decay in the very early Universe.Comment: 9 pages, 2 figures. Corrected some minor misprint

Evolvability and trait function predict phenotypic divergence of plant populations

Understanding the causes and limits of population divergence in phenotypic traits is a fundamental aim of evolutionary biology, with the potential to yield predictions of adaptation to environmental change. Reciprocal transplant experiments and the evaluation of optimality models suggest that local adaptation is common but not universal, and some studies suggest that trait divergence is highly constrained by genetic variances and covariances of complex phenotypes. We analyze a large database of population divergence in plants and evaluate whether evolutionary divergence scales positively with standing genetic variation within populations (evolvability), as expected if genetic constraints are evolutionarily important. We further evaluate differences in divergence and evolvability-divergence relationships between reproductive and vegetative traits and between selling, mixed-mating, and outcrossing species, as these factors are expected to influence both patterns of selection and evolutionary potentials. Evolutionary divergence scaled positively with evolvability. Furthermore, trait divergence was greater for vegetative traits than for floral (reproductive) traits, but largely independent of the mating system. Jointly, these factors explained similar to 40% of the variance in evolutionary divergence. The consistency of the evolvability-divergence relationships across diverse species suggests substantial predictability of trait divergence. The results are also consistent with genetic constraints playing a role in evolutionary divergence

Escaped oilseed rape: Occurrence in the agricultural landscape and potential pollen-mediated gene flow from crop oilseed rape

To assess the role of feral oilseed rape (OSR) plants as resources for pollinators and avenues for gene flow, we compared occurrence of feral populations in standardized agricultural landscapes, using a landscape ecological approach. The occurrence of feral and volunteer populations was investigated in relation to differences in road length and width, number of OSR fields, and landscape scale. The potential for pollen-mediated gene flow from crop to feral oilseed rape was investigated with fluorescent dye in a field experiment. Moreover, greenhouse estimates of pollen germination rate and pollen tube growth rate were performed to get an indication of siring success in crop and feral plants. Escaped OSR occurred in 14 out of the 16 investigated landscapes, and feral populations were more common alongside large roads than small roads in large-scale landscapes. The number of plants in a habitat ranged from 1-160 individuals, with 1-19 habitats per landscape. In the field experiment with fluorescent dye, no transfer of dye was detected during early flowering in May. At the end of the flowering period in June, transfer of dye was found in 71.4% of the feral plants, showing that significant transfer, most likely by pollinators, occurred from the field to the feral plants. There was no difference in pollen germination rate between crop and feral plants. Pollen tube growth rate was significantly higher in feral oilseed rape than in the crop (P < 0.001). Our results contribute to increased understanding of i) the utilization of feral populations by pollinators in an intensively farmed agricultural landscape, and ii) crop-feral gene flow within OSR

Valaisinohjaimen muuntaminen langattomaksi

Toimeksiantajalla oli tarve hyödyntää langattomuutta laitteissaan niiden asennuksen ja asennuksen muunneltavuuden helpottamiseksi. Työssä tuli selvittää toimenpiteet liikkeentunnistukseen perustuvan valaisinohjaimen muuntamiseksi täysin langattomaksi. Erilaisia langattomia järjestelmiä vertailemalla tuli löytää soveltuvin vaihtoehto ottaen huomioon toimeksiantajan tarpeet ja resurssien rajoitteet. Laitteen toimintalohkojen toteutuksessa huomioitavia seikkoja tuli selvittää ja esittää lohkojen toteutusehdotukset. Laitteesta tuli valmistaa toimiva testikytkentä jatkokehitystä varten. Erilaisia järjestelmiä etsittiin alan kirjallisuudesta ja Internetistä sekä tiedusteltiin komponenttijakelijoilta. Toimintalohkojen toteutusehdotukset selvitettiin etsimällä soveltuvia komponentteja Internetistä ja esitteistä sekä simuloimalla kytkentöjä. Langattomaksi järjestelmäksi valittiin Z-Wave. Valaisinohjaimen liiketunnistin- ja ohjausyksikön toteutusehdotukset painottuivat liiketunnistinyksikön virrankulutuksen vähentämiseen. Kokonaisuudesta ei ajan puutteen vuoksi tehty testikytkentää. Keskeiset toimintalohkot kuitenkin todettiin testeillä toimiviksi. Tehty selvitystyö antoi viitteet sille, että myös pienillä resursseilla toimivat elektroniikkavalmistajat pystyivät suunnittelemaan ja tuomaan markkinoille kiinteistöautomaation langattomia laitteita. Toteuttaakseen tämän tuli niiden käyttää tietynlaisen langattoman järjestelmän moduuleita ja perehtyä syvällisesti laitteiden virrankulutukseen.The commissioner of this thesis had a need for a wireless communication system that could be used in their products. The aim was to facilitate the installation of the products and improve the modifiability of the installation. The purpose of this research was to determine the operations to modify luminaire controller to use wireless connection. The most applicable wireless system had to be selected taking into account the needs and the resources of the commissioner. Implementation proposals for the functional blocks needed to be represented and functional test device had to be built. Different systems were searched on the literature of the branch and from the Internet, as well as inquired of component distributors. The implementation proposals for the functional blocks were determined by searching applicable components from the Internet and brochures as well as by simulating different connections. Z-Wave was selected to be used in the wireless luminaire controller. The implementation proposals for the functional blocks were focused on current consumption reduc- tion. The test device was not built in its totality because of the lack of time. The essential functional blocks were verified to be functional by tests. The results of this study proposed that also companies with minor resources are able to design and launch on the market wireless building automation devices. This could be attained by using certain wireless system modules and researching a current consumption of devices