Creating possibilities for collective creativity : Brokerage Functions in Practice-Based Innovation

In the network era, creative achievements like innovations are more and more often created in interaction among different actors. The complexity of today‘s problems transcends the individual human mind, requiring not only individual but also collective creativity. In collective creativity, it is impossible to trace the source of new ideas to an individual. Instead, creative activity emerges from the collaboration and contribution of many individuals, thereby blurring the contribution of specific individuals in creating ideas. Collective creativity is often associated with diversity of knowledge, skills, experiences and perspectives. Collaboration between diverse actors thus triggers creativity and gives possibilities for collective creativity. This dissertation investigates collective creativity in the context of practice-based innovation. Practice-based innovation processes are triggered by problem setting in a practical context and conducted in non-linear processes utilising scientific and practical knowledge production and creation in cross-disciplinary innovation networks. In these networks diversity or distances between innovation actors are essential. Innovation potential may be found in exploiting different kinds of distances. This dissertation presents different kinds of distances, such as cognitive, functional and organisational which could be considered as sources of creativity and thus innovation. However, formation and functioning of these kinds of innovation networks can be problematic. Distances between innovating actors may be so great that a special interpretation function is needed – that is, brokerage. This dissertation defines factors that enhance collective creativity in practice-based innovation and especially in the fuzzy front end phase of innovation processes. The first objective of this dissertation is to study individual and collective creativity at the employee level and identify those factors that support individual and collective creativity in the organisation. The second objective is to study how organisations use external knowledge to support collective creativity in their innovation processes in open multi-actor innovation. The third objective is to define how brokerage functions create possibilities for collective creativity especially in the context of practice-based innovation. The research objectives have been studied through five substudies using a case-study strategy. Each substudy highlights various aspects of creativity and collective creativity. The empirical data consist of materials from innovation projects arranged in the Lahti region, Finland, or materials from the development of innovation methods in the Lahti region. The Lahti region has been chosen as the research context because the innovation policy of the region emphasises especially the promotion of practice-based innovations. The results of this dissertation indicate that all possibilities of collective creativity are not utilised in internal operations of organisations. The dissertation introduces several factors that could support collective creativity in organisations. However, creativity as a social construct is understood and experienced differently in different organisations, and these differences should be taken into account when supporting creativity in organisations. The increasing complexity of most potential innovations requires collaborative creative efforts that often exceed the boundaries of the organisation and call for the involvement of external expertise. In practice-based innovation different distances are considered as sources of creativity. This dissertation gives practical implications on how it is possible to exploit different kinds of distances knowingly. It underlines especially the importance of brokerage functions in open, practice-based innovation in order to create possibilities for collective creativity. As a contribution of this dissertation, a model of brokerage functions in practice-based innovation is formulated. According to the model, the results and success of brokerage functions are based on the context of brokerage as well as the roles, tasks, skills and capabilities of brokers. The brokerage functions in practice-based innovation are also possible to divide into social and cognitive brokerage.

The Forms and Functions of Multilingual Practices in Early Modern School Drama from the King‟s School, Canterbury

Käsittelen tutkimuksessani monikielisyyden ilmenemistä Canterburyn katedraalikoulun oppilaiden 1600-luvun loppupuoliskolla esittämissä näytelmissä, jotka löytyvät käsikirjoituksesta Lit.Ms.E41 (Canterburyn katedraalin arkisto). Tämä käsikirjoitus sisältää puheita ja näytelmiä, joiden kielinä ovat englanti, latina ja vähemmissä määrin myös kreikka. Useissa näytelmissä esiintyy koodinvaihtoa näiden kielten välillä, ja tutkielmassani selvitän, millaisia syntaktisia ilmenemismuotoja ja pragmaattisia merkityksiä koodinvaihdolla on. Teoreettinen viitekehykseni on yhdistelmä filologista ja lingvististä lähestymistapaa. Olen sisällyttänyt tutkielmaani aiemman koodinvaihdon tutkimuksen lisäksi Brownin ja Levinsonin kohteliaisuusteorian, jonka avulla erityisesti puhujien välisiin sosiaalisiin suhteisiin liittyviä koodinvaihdon funktioita voidaan luokitella. Koska historiallinen koodinvaihto on tutkimusaiheena vielä melko tuore, käsittelen perusteellisesti erilaisia metodologisia ratkaisuja. Valitsemani metodi yhdistää perinteisen filologisen lähiluvun pragmaattiseen analyysiin, jonka kautta työssäni vaikuttavat muun muassa rationaalisuuden ja empatian käsitteet. Analyysini perusteella kävi ilmi, että erityisen yleinen koodinvaihdon funktio on mahdollistaa intertekstuaalisuus, jolla edelleen voidaan ilmaista esimerkiksi solidaarisuutta eli sosiaalista läheisyyttä tai loukata puhuteltavaa. Solidaarisuus oli myös ilman intertekstuaalisuutta yleinen koodinvaihdon funktio. Näiden lisäksi koodinvaihdon funktioita olivat muun muassa kasvoja uhkaavat teot, eufemismit, stilistiset efektit sekä diskurssin avustaminen. Syntaktisten ilmenemismuotojen osalta keskeisin havainto oli, että koodinvaihdon ja lainaamisen erottaminen ei ole tarpeellista tai edes kannattavaa kaikissa tilanteissa. Lisäksi voitiin todeta, että valittu metodi soveltui hyvin aineiston analysoimiseen, ja sitä tulisi soveltaa mahdollisuuksien mukaan laajempaan materiaaliin sekä muiden pragmaattisten ilmiöiden tutkimiseen.

TR(i)P, TR(i)P, hooray : new functions for TRPC2 and TRPC3

Kalciumjonen påverkar många aspekter av cellbiologi, från fertiliseringen av äggcellen till tillväxt och differentiering av alla typer av celler. Störningar i hur kalciumjonerna transporteras in och friges i cellerna kan ha stor betydelse för hur sjukdomar framskrider. På grund av detta är det viktigt att studera hur kalciumtransportörer såsom kalciumkanaler fungerar och hur de påverkar cellernas funktioner. I avhandlingen har klassiska transient receptorpotential (TRPC) katjonkanaler studerats. Dessa kanaler är permeabla för kalcium och aktiveras nedströms av G-proteinkopplade receptorer. Resultaten som presenteras i avhandlingen visar på nya funktioner för TRPC2- och TRPC3-kanalerna. Utöver TRPC3-kanalens roll i plasmamembranen, där den medverkar i receptorreglerat kalciuminflöde, tyder våra resultat på att TRPC3 har en potentiell intracellulär roll. Vid överuttryck av kanalen lokaliserade kanalen till endoplasmatiska nätverket där kanalen friger intracellulärt kalcium. TRPC2 har en viktig funktion i möss där kanalen reglerar hur djuret reagerar på feromoner. Våra resultat tyder på att TRPC2 är involverad i autokrin sfingosin-1-fosfat (S1P)-signalering. S1P som produceras i cellerna transporterades ut från cellerna varpå det aktiverade S1P2-receptorer på plasmamembranen. Diacylglycerol som bildas som en följd av aktivering av S1P2-receptorn aktiverade i sin tur inflöde av extracellulärt kalcium. Våra resultat indikerar att TRPC2 är kanalen som förmedlar detta kalciuminflöde. I sköldkörtelceller studerades nedströms effekter för TRPC2. Kanalen reglerade negativt cAMP-produktionen i cellerna vilket hämmar extracellulärt signalreglerat kinas 1/2 (ERK1/2). När uttrycket för TRPC2 minskades i cellerna, ökades produktionen av cAMP och fosforyleringen av ERK1/2, vilket resulterade i ökat uttryck för receptorn för sköldkörtelstimulerande hormon. Slutligen, presenterar vi resultat som tyder på att TRPC2 är viktigt för sekretion av prekursorn till sköldkörtelhormon.

Influence of distal ileum exclusion on hepatic and renal functions in presence of extrahepatic cholestasis

OBJECTIVE: To verify whether the ileal exclusion interferes with liver and kidney functional changes secondary to extrahepatic cholestasis.METHODS: We studied 24 rats, divided into three groups with eight individuals each: Group 1 (control), Group 2 (ligation of the hepatic duct combined with internal biliary drainage), and Group 3 (bile duct ligation combined with internal biliary drainage and exclusion of the terminal ileum). Animals in Group 1 (control) underwent sham laparotomy. The animals of groups 2 and 3 underwent ligation and section of the hepatic duct and were kept in cholestasis for four weeks. Next, they underwent an internal biliary bypass. In Group 3, besides the biliary-enteric bypass, we associated the exclusion of the last ten centimeters of the terminal ileum and carried out an ileocolic anastomosis. After four weeks of monitoring, blood was collected from all animals of the three groups for liver and kidney biochemical evaluation (albumin, ALT, AST, direct and indirect bilirubin, alkaline phosphatase, cGT, creatinine and urea).RESULTS: there were increased values of ALT, AST, direct bilirubin, cGT, creatinine and urea in rats from Group 3 (p < 0.05).CONCLUSION: ileal exclusion worsened liver and kidney functions in the murine model of extrahepatic cholestasis, being disadvantageous as therapeutic procedure for cholestatic disorders.

Localization, Frequency, and Functions of Filled Pauses: Five American Politicians’ Use of er and erm in the Talk Show Larry King Live

Tämän pro gradu– tutkielman tavoitteena oli testata täytettyjen taukojen (er ja erm) esiintymistiheyttä, sijaintia kieliopillisessa rakenteessa sekä funktioita Kjellmerin (2003) korpus-tutkimuksessa. Materiaalina käytin viiden yhdysvaltalaisen poliitikon puhetta keskusteluohjelmasta Larry King Live. Tutkimuksessani sovelsin Kjellmerin tutkimusmenetelmiä, joita muokkasin huomattavasti suppeampaan materiaaliini sopiviksi. Lähestymistapani oli täten induktiivinen toisin kuin testatussa tutkimuksessa. Materiaalini oli tarkoituksellisesti rajattu, sillä halusin selvittää, kuvaavatko Kjellmerin laajaan materiaaliin perustuvat tutkimustulokset myös täytettyjen taukojen käyttöä suppeammassa materiaalissa. Materiaalini (kokonaisuudessaan 101 minuuttia) transkriboin ortografisesti. Analyysissäni arvioin täytettyjen taukojen esiintymistiheyden puhujakohtaisesti ja koko ryhmälle suhteuttamalla täytettyjen taukojen lukumäärän kokonaissanamäärään. Tämän jälkeen tein perinteisen kielioppianalyysin rakenteista, joita edeltää tai joissa esiintyy täytetty tauko, ja täytettyjen taukojen sijainnin perusteella luokittelin ne sana-, lauseke-, ja lausetasolle. Lopuksi analysoin täytettyjen taukojen käyttöä soveltaen Kjellmerin ehdottamia funktioita (hesitaatio, vuorottelujäsennyksen merkitseminen, huomion herättäminen ja kontaktin luominen, korostus ja korjaus) ja niiden piirteitä omaan materiaaliini. Tutkimukseni perusteella täytetyt tauot esiintyvät tutkitun viiden poliitikon puheessa suhteellisen usein. Puhujakohtaiset eroavaisuudet olivat kuitenkin huomattavat. Kieliopillisen luokitteluni mukaan sana-, lauseke- ja lausetasot eivät täysin kuvaa täytettyjen taukojen sijoittumista, sillä täytetyt tauot edelsivät mm. määre-lauseita, jotka eivät vastaa lausetasoa englannin kielessä. Materiaalini funktioanalyysi osoitti, että täytetyt tauot yleensä vastaavat yhtä tai useampaa Kjellmerin ehdottamaa funktioita. Lisäksi tutkimukseni mukaan täytetyillä tauoilla on ainakin yksi rakenteellinen funktio. Analyysini perusteella Kjellmerin tutkimustulokset ovat siis pääosin sovellettavissa suppeampaan materiaaliin. Puutteiksi hänen tutkimuksessaan osoittautuivat funktioanalyysille tärkeän kontekstuaalisen informaation puute sekä keskittyminen täytettyihin taukoihin, jotka esiintyvät vain tietyissä kielioppirakenteissa. Yleisesti voin tutkimukseni pohjalta todeta, että täytetyt tauot ovat vielä vajaasti tunnettuja ja että kieliopillisen sijoituksen ja funktioiden lisätutkimus on tarpeellista.

Novel Functions of ErbB4 and NRG-1 in Development and Cancer

Cells communicate, or signal, with each other constantly to ensure proper functioning of tissues and organs. Cell signaling is often performed by interplay of receptors and ligands that bind these receptors. ErbB receptors (epidermal growth factor receptors, EGFR, HER) bind extracellular growth factors and transduce these signals inside of cells. ErbB dysfunction promotes carcinogenesis, and also results in numerous defects during normal development. This study focused on the functions of one member of the ErbB receptor family, ErbB4, and growth factor, neuregulin-1 (NRG-1), that can bind and activate ErbB4. This study aimed to find novel functions of ErbB4 and NRG-1. Hypoxia, or deficiency of oxygen, is common in cancer and ischemic conditions. One of the key findings of the work was the identification and characterization of a cross-talk between ErbB4 and Hypoxia-inducible factor 1α (HIF-1α), the central mediator of hypoxia signaling. ErbB4 activation by NRG-1 was found to increase HIF-1α activity. Interestingly, this regulation occurred in reciprocal manner as HIF-1α was also able to increase protein levels of NRG-1 and ErbB4. Moreover, expression of NRG-1 and ErbB4 was associated with HIF activity in vivo in human clinical samples and in mice. Reduction of functional ErbB4 in developing zebrafish embryos resulted in defects in development of the skeletal muscles. To study ErbB4 functions in pathological situation in humans, clinical samples of serous ovarian carcinoma were analyzed using tissue microarrays and real-time RT-PCR. A specific isoform of ErbB4, CYT-1, was associated with poor survival in serous ovarian cancer and increased anchorage independent growth of ovarian cancer cells in vitro. These observations demonstrate that ErbB4 and NRG-1 are essential regulators of cellular response to hypoxia, of development, and of ovarian carcinogenesis.

Training executive functions in the laboratory and in real life : cognitive consequences of computer-based exercises and bilingualism

The question of the trainability of executive functions and the impact of such training on related cognitive skills has stirred considerable research interest. Despite a number of studies investigating this, the question has not yet been solved. The general aim of this thesis was to investigate two very different types of training of executive functions: laboratory-based computerized training (Studies I-III) and realworld training through bilingualism (Studies IV-V). Bilingualism as a kind of training of executive functions is based on the idea that managing two languages requires executive resources, and previous studies have suggested a bilingual advantage in executive functions. Three executive functions were studied in the present thesis: updating of working memory (WM) contents, inhibition of irrelevant information, and shifting between tasks and mental sets. Studies I-III investigated the effects of computer-based training of WM updating (Study I), inhibition (Study II), and set shifting (Study III) in healthy young adults. All studies showed increased performance on the trained task. More importantly, improvement on an untrained task tapping the trained executive function (near transfer) was seen in Study I and II. None of the three studies showed improvement on untrained tasks tapping some other cognitive function (far transfer) as a result of training. Study I also used PET to investigate the effects of WM updating training on a neurotransmitter closely linked to WM, namely dopamine. The PET results revealed increased striatal dopamine release during WM updating performance as a result of training. Study IV investigated the ability to inhibit task-irrelevant stimuli in bilinguals and monolinguals by using a dichotic listening task. The results showed that the bilinguals exceeded the monolinguals in inhibiting task-irrelevant information. Study V introduced a new, complementary research approach to study the bilingual executive advantage and its underlying mechanisms. To circumvent the methodological problems related to natural groups design, this approach focuses only on bilinguals and examines whether individual differences in bilingual behavior correlate with executive task performances. Using measures that tap the three above-entioned executive functions, the results suggested that more frequent language switching was associated with better set shifting skills, and earlier acquisition of the second language was related to better inhibition skills. In conclusion, the present behavioral results showed that computer-based training of executive functions can improve performance on the trained task and on closely related tasks, but does not yield a more general improvement of cognitive skills. Moreover, the functional neuroimaging results reveal that WM training modulates striatal dopaminergic function, speaking for training-induced neural plasticity in this important neurotransmitter system. With regard to bilingualism, the results provide further support to the idea that bilingualism can enhance executive functions. In addition, the new complementary research approach proposed here provides some clues as to which aspects of everyday bilingual behavior may be related to the advantage in executive functions in bilingual individuals.

Effects of fasting and refeeding on the metabolic functions of the turtle Kinosternon scorpioides (Linnaeus, 1766) raised in captivity

The metabolic responses of adult and young freshwater Kinosternon scorpioides turtles raised in captivity were evaluated. Two experiments were performed: a) blood metabolite changes caused by food deprivation, and b) liver and muscle glycogen and total lipid differences after fasting and refeeding. Blood glucose concentration of young animals was susceptible to food deprivation. In both groups this metabolite decreased after 30 days of fasting. Feeding for 15 days did not recover blood glucose. Total seric proteins were not affected by food deprivation. Fasting decreased blood urea nitrogen and the highest difference was found around 30 days. Uric acid increased in young animals after 60 days of fasting. Triacylglicerol decreased after 15 days of fasting and refeeding for 15 days recovered the pre-fasting levels. Free fatty acid plasma tended to increase around 15 days of fasting. Liver glycogen decreased at day 15 of fasting, being stable thereafter while muscle glycogen decreased at a slower rate. Total liver lipid stabilized after 30 days and then decreased 70% after 60 days of fasting. Muscle lipids remained stable throughout fasting. It could be concluded that fasting of Kinosternon scorpioides led to metabolic adaptations similar to the one reported from reptiles and fish.

Long term dietary deficiency in steers: vital functions and T3 and IGF-1 relationships

To evaluate the influence of diets with different degrees of energy deficiency on the hormonal profile and vital functions, 12 steers were randomly distributed into 3 groups of 4 animals. For 140 days, each group received (G1) a diet to promote a weight gain of 900gr/day (17.7 Mcal/d DE and 13% CP), (G2) 80% of the maintenance requirements (5.8 Mcal/d DE and 7% CP), or (G3) 60% of the maintenance requirements (4.7 Mcal/d DE and 5% CP). In G2 and G3, the energy deficit caused a marked decrease in the heart rate and respiratory rate and a reduction in the blood levels of Insulin like growth factor-1 (IGF-1) and triiodothyronine (T3). The decrease in heart rate, respiratory movement and, to a lesser extent, reduction of the rectal temperature, reflected the low status of energy and was negatively impacted by the low levels of T3. There was a strong correlation between the hormones T3 and IGF-1 (r=0.833). There were also strong correlations between T3 and HR (r=0.701), T3 and RR (r=0.632), IGF-1 and HR (r=0.731), and IGF-1 and RR (r=0.679). There were intermediate correlations between T3 and TºC (r=0.484), T3 and insulin (r=0.506), IGF-1 and insulin (r=0.517), and IGF-1 and TºC (r=0.548). This study showed the influence of a long period of providing an energy-deficient diet on animal performance, correlating hormonal status and vital functions in growing cattle. The results indicated that the evaluated parameters represent an important tool for the early detection of dietary deficiency.

Risk-return trade-off and autocorrelation

A trade-off between return and risk plays a central role in financial economics. The intertemporal capital asset pricing model (ICAPM) proposed by Merton (1973) provides a neoclassical theory for expected returns on risky assets. The model assumes that risk-averse investors (seeking to maximize their expected utility of lifetime consumption) demand compensation for bearing systematic market risk and the risk of unfavorable shifts in the investment opportunity set. Although the ICAPM postulates a positive relation between the conditional expected market return and its conditional variance, the empirical evidence on the sign of the risk-return trade-off is conflicting. In contrast, autocorrelation in stock returns is one of the most consistent and robust findings in empirical finance. While autocorrelation is often interpreted as a violation of market efficiency, it can also reflect factors such as market microstructure or time-varying risk premia. This doctoral thesis investigates a relation between the mixed risk-return trade-off results and autocorrelation in stock returns. The results suggest that, in the case of the US stock market, the relative contribution of the risk-return trade-off and autocorrelation in explaining the aggregate return fluctuates with volatility. This effect is then shown to be even more pronounced in the case of emerging stock markets. During high-volatility periods, expected returns can be described using rational (intertemporal) investors acting to maximize their expected utility. During lowvolatility periods, market-wide persistence in returns increases, leading to a failure of traditional equilibrium-model descriptions for expected returns. Consistent with this finding, traditional models yield conflicting evidence concerning the sign of the risk-return trade-off. The changing relevance of the risk-return trade-off and autocorrelation can be explained by heterogeneous agents or, more generally, by the inadequacy of the neoclassical view on asset pricing with unboundedly rational investors and perfect market efficiency. In the latter case, the empirical results imply that the neoclassical view is valid only under certain market conditions. This offers an economic explanation as to why it has been so difficult to detect a positive tradeoff between the conditional mean and variance of the aggregate stock return. The results highlight the importance, especially in the case of emerging stock markets, of noting both the risk-return trade-off and autocorrelation in applications that require estimates for expected returns.

Neurocognitive changes in early-stage Parkinson's disease : functional and structural brain correlates of memory and verbal functions

Resultaten påvisade små, men mätbara försämringar i minnes- och verbal förmåga hos personer som haft Parkinsons sjukdom under tre år. Jämfört med en kontrollgrupp uppvisade Parkinsonpatienter avvikande responser i hjärnans elektriska aktivitet under en korttidsminnesuppgift, och de presterade även sämre i olika typer av andra minnesuppgifter. Försämring i en specifik typ av minnesuppgift korrelerade med förminskad volym i höger hjärnhalva. Samband hittades också mellan sämre verbal förmåga och förminskad volym i djupa hjärnstrukturer. Förminskad hjärnvolym har tidigare påvisats hos dementa patienter i senare sjukdomsstadier. Forskningsresultaten bidrar med ny kunskap om kognitiva symptom och deras neurala bakgrund vid Parkinsons sjukdom. De tyder också på att tidig kognitiv funktionsnedsättning kan identifieras, vilket kan bidra till utvecklingen av sjukdomens behandling. Parkinsons sjukdom är den näst vanligaste neurogeriatriska sjukdomen efter Alzheimers sjukdom. Symptomen uppstår som följd av förminskad produktion av hjärnans transmittorämne dopamin. Parkinsons sjukdom har traditionellt betraktats som en progressiv motorisk sjukdom. Ny forskning tyder på att multipla hjärnsystem skadas, vilket resulterar i att även tankeprocesser påverkas. 75-80% uppskattas insjukna i demens 10-15 år efter diagnos, men det kognitiva sjukdomsförloppet och orsaken till demenssymptomen är tillsvidare okänd. I Finland uppskattas ca 10-12 000 personer ha Parkinsons sjukdom, varav ca 3 000 uppskattas ha demens. ----------------------------------------------------------------------------------------------------------------------------------------------------- Tutkimuksessa todettiin lieviä muutoksia muisti- ja kielellisissä toiminnoissa alle kolme vuotta sairastaneilla Parkinson-potilailla. Potilailla havaittiin poikkeavia aivosähkötoiminnan vasteita lyhytkestoista muistia mittaavan tehtävän aikana. Potilaat suoriutuivat myös verrokkiryhmää heikommin useissa muistitehtävissä. Heikentynyt tahaton muisti liittyi pienempään aivokuoren harmaan aineen paikalliseen tilavuuteen. Heikompi kielellinen suoriutuminen liittyi pienempään harmaan aineen tilavuuteen aivojen syvissä rakenteissa. Pienentyneitä aivorakenteiden tilavuuksia on aiemmin todettu dementoituneilla Parkinson-potilailla sairauden myöhemmissä vaiheissa. Tutkimustulokset tuovat uutta tietoa Parkinsonin taudin kognitiivisista oireista ja niiden aivoperäisestä taustasta. Tulosten perusteella on mahdollista tunnistaa jo varhaisia kognitiivisia muutoksia, mikä voi mahdollistaa tehokkaamman hoidon kohdentamisen. Parkinsonin tauti on Alzheimerin taudin jälkeen toiseksi yleisin neurogeriatrinen sairaus. Oirekuva liittyy aivojen dopaminergisen järjestelmän rappeutumiseen. Perinteisesti liikehäiriösairaudeksi luokiteltu sairaus vaurioittaa lukuisia muita aivojärjestelmiä aiheuttaen muutoksia myös mm. ajattelutoiminnoissa. Pitkään sairastaneista 75–80 prosentilla esiintyy dementiaoireita, mutta oireiden syy ja kehityskaari tunnetaan toistaiseksi huonosti. Suomessa on arviolta 10–12 000 Parkinson-potilasta, joista noin 3 000 arvioidaan kärsivän dementiaoireista.

Excessive functions, Appell polynomials and optimal stopping

The main topic of the thesis is optimal stopping. This is treated in two research articles. In the first article we introduce a new approach to optimal stopping of general strong Markov processes. The approach is based on the representation of excessive functions as expected suprema. We present a variety of examples, in particular, the Novikov-Shiryaev problem for Lévy processes. In the second article on optimal stopping we focus on differentiability of excessive functions of diffusions and apply these results to study the validity of the principle of smooth fit. As an example we discuss optimal stopping of sticky Brownian motion. The third research article offers a survey like discussion on Appell polynomials. The crucial role of Appell polynomials in optimal stopping of Lévy processes was noticed by Novikov and Shiryaev. They described the optimal rule in a large class of problems via these polynomials. We exploit the probabilistic approach to Appell polynomials and show that many classical results are obtained with ease in this framework. In the fourth article we derive a new relationship between the generalized Bernoulli polynomials and the generalized Euler polynomials.

PDM system functions and utilizations analysis to improve efficiency of sheet metal product design and manufacturing

This study will concentrate on Product Data Management (PDM) systems, and sheet metal design features and classification. In this thesis, PDM is seen as an individual system which handles all product-related data and information. The meaning of relevant data is to take the manufacturing process further with fewer errors. The features of sheet metals are giving more information and value to the designed models. The possibility of implementing PDM and sheet metal features recognition are the core of this study. Their integration should make the design process faster and manufacturing-friendly products easier to design. The triangulation method is the basis for this research. The sections of this triangle are: scientific literature review, interview using the Delphi method and the author’s experience and observations. The main key findings of this study are: (1) the area of focus in triangle (the triangle of three different point of views: business, information exchange and technical) depends on the person’s background and their role in the company, (2) the classification in the PDM system (and also in the CAD system) should be done using the materials, tools and machines that are in use in the company and (3) the design process has to be more effective because of the increase of industrial production, sheet metal blank production and the designer’s time spent on actual design and (4) because Design For Manufacture (DFM) integration can be done with CAD-programs, DFM integration with the PDM system should also be possible.

Decreased spermatogenic and androgenic testicular functions in adult rats submitted to immobilization-induced stress from prepuberty

We investigated whether chronic stress applied from prepuberty to full sexual maturity interferes with spermatogenic and androgenic testicular functions. Male Wistar rats (40 days old) were immobilized 6 h a day for 60 days. Following immobilization, plasma concentrations of corticosterone and prolactin increased 135% and 48%, respectively, while plasma luteinizing hormone and testosterone presented a significant decrease of 29% and 37%, respectively. Plasma concentration of follicle-stimulating hormone was not altered in stressed rats. Chronic stress reduced the amount of mature spermatids in the testis by 16% and the spermatozoon concentration in the cauda epididymidis by 32%. A 17% reduction in weight and a 42% decrease in DNA content were observed in the seminal vesicle of immobilized rats but not in its fructose content. The growth and secretory activity of the ventral prostate were not altered by chronic stress.

Carbon monoxide: from toxin to endogenous modulator of cardiovascular functions

Carbon monoxide (CO) is a pollutant commonly recognized for its toxicological attributes, including CNS and cardiovascular effects. But CO is also formed endogenously in mammalian tissues. Endogenously formed CO normally arises from heme degradation in a reaction catalyzed by heme oxygenase. While inhibitors of endogenous CO production can raise arterial pressure, heme loading can enhance CO production and lead to vasodepression. Both central and peripheral tissues possess heme oxygenases and generate CO from heme, but the inability of heme substrate to cross the blood brain barrier suggests the CNS heme-heme oxygenase-CO system may be independent of the periphery. In the CNS, CO apparently acts in the nucleus tractus solitarii (NTS) promoting changes in glutamatergic neurotransmission and lowering blood pressure. At the periphery, the heme-heme oxygenase-CO system can affect cardiovascular functions in a two-fold manner; specifically: 1) heme-derived CO generated within vascular smooth muscle (VSM) can promote vasodilation, but 2) its actions on the endothelium apparently can promote vasoconstriction. Thus, it seems reasonable that the CNS-, VSM- and endothelial-dependent actions of the heme-heme oxygenase-CO system may all affect cardiac output and vascular resistance, and subsequently blood pressure.