Stochastic properties of the plant circadian clock

Circadian clocks are gene regulatory networks whose role is to help the organisms to cope with variations in environmental conditions such as the day/night cycle. In this work, we explored the effects of molecular noise in single cells on the behaviour of the circadian clock in the plant model species Arabidopsis thaliana. The computational modelling language Bio-PEPA enabled us to give a stochastic interpretation of an existing deterministic model of the clock, and to easily compare the results obtained via stochastic simulation and via numerical solution of the deterministic model. First, the introduction of stochasticity in the model allowed us to estimate the unknown size of the system. Moreover, stochasticity improved the description of the available experimental data in several light conditions: noise-induced fluctuations yield a faster entrainment of the plant clock under certain photoperiods and are able to explain the experimentally observed dampening of the oscillations in plants under constant light conditions. The model predicts that the desynchronization between noisy oscillations in single cells contributes to the observed damped oscillations at the level of the cell population. Analysis of the phase, period and amplitude distributions under various light conditions demonstrated robust entrainment of the plant clock to light/dark cycles which closely matched the available experimental data

Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat

Henkilöstön vaihtuvuus ja siihen liittyvät tekijät telemarkkinointialalla : case: Gainer Oy

Tämä opinnäytetyö toteutettiin toimeksiantosopimuksena Gainer Oy:lle, joka on toiminut telemarkkinoinnin alalla jo vuodesta 1984. Opinnäytetyön tutkimusstrategiaksi valittiin case study eli tapaustutkimus. Käytimme tutkimusmenetelmänä kvalitatiivista eli laadullista tutkimusta. Tavoitteenamme oli tutkia ja selvittää henkilöstön vaihtuvuutta ja siihen liittyviä tekijöitä alalla, jossa henkilöstön vaihtuvuus koetaan ongelmaksi. Teoriaosuudessa käsittelemme teoreettisen viitekehyksen liittyen työnantajan keinoihin vaikuttaa työntekijän sitouttamiseen. Tämä on jaettu kahteen osa-alueeseen, jotka ovat rekrytointi sekä työhyvinvointi ja osaamisen kehittäminen. Empiirisessä osiossa päädyimme käyttämään puolistrukturoitua teemahaastattelua, joka toteutettiin suurimmaksi osaksi puhelimitse sekä muutama haastattelu tehtiin kasvotusten. Teemahaastattelu valikoitui parhaimmaksi menetelmäksi johtuen aiheen moniulotteisuudesta. Avoimella haastattelulla emme olisi välttämättä saaneet merkittävää tietoa samassa mittakaavassa kuin puolistrukturoidulla mallilla. Opinnäytetyön tuloksena päädyimme esittämään toimeksiantajalle muutamia kehitysehdotuksia. Haastatteluista johdetuilla päätelmillä saatettaisiin parantaa rekrytoinnin onnistumista, joka osaltaan parantaa kannattavuutta niin tuloksellisesti, kuin henkilöstön resurssejakin säästäen. Kehitysehdotuksia muodostui myös muihin osa-alueisiin liittyen. Näillä on myös vaikutusta henkilöstön yleiseen työhyvinvointiin ja työssä jaksamiseen.This thesis was carried out as a commission agreement for Gainer Oy, which has operated in the field of telemarketing since 1984. Our study was carried out as a case study using qualitative approach as our research method. Our objective was to study personnel turnover and matters relating to it in a field where personnel turnover is seen as a problem. In the theoretical section of the study we deal with the theoretical frame of reference related to the employer's means to influence employee engagement. This is divided into two sections that are recruiting, and occupational health and development of skills. In the empirical part of our study, we ended up using half-structured theme interviews, which were mainly carried out by telephone. A few interviews were carried out face-to-face. Theme interview was selected to be the best method because of the multidimensionality of the subject. By using open interviews, we would not necessarily have received as much significant information as by using the half-structured model. As a result of our study, we presented a few development proposals for our client/commissioner. The conclusions drawn from the interviews may lead to more successful recruiting, which in turn improves viability both in terms of productivity and by saving the resources of the personnel. There were also other development proposals concerning other areas. The results of the study may also help to improve the general well-being at work and coping with one’s workload

Common variation near CDKN1A, POLD3 and SHROOM2 influences colorectal cancer risk

We performed a meta-analysis of five genome-wide association studies to identify common variants influencing colorectal cancer (CRC) risk comprising 8,682 cases and 9,649 controls. Replication analysis was performed in case-control sets totaling 21,096 cases and 19,555 controls. We identified three new CRC risk loci at 6p21 (rs1321311, near CDKN1A; P = 1.14 × 10 -10), 11q13.4 (rs3824999, intronic to POLD3; P = 3.65 × 10 -10) and Xp22.2 (rs5934683, near SHROOM2; P = 7.30 × 10 -10) This brings the number of independent loci associated with CRC risk to 20 and provides further insight into the genetic architecture of inherited susceptibility to CRC.</p