20 resultados para maternal behavior

em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland


Relevância:

60.00% 60.00%

Publicador:

Resumo:

In animal psychology, the open-field (OF) test is a traditional method for studying different aspects of rodent behavior, with thigmotaxis (i.e., wallseeking behavior) being one of the best validated OF parameters employed to measure emotionality. The main purpose of the present study was to investigate the selection response in mice selectively bred for high and low levels of OF thigmotaxis (the HOFT and LOFT lines, respectively). The mice (N = 2048) were selected for 23 generations, resulting in bidirectional phenotypic divergence between the two lines; that is, the HOFT mice were more thigmotactic (i.e., more emotional) than the LOFT mice across the different generations. The origin of the line difference in thigmotaxis was further investigated by using the crossfostering paradigm, with the results suggesting that the divergence between the two lines was primarily innate in origin and not influenced by differing maternal behavior. The stability of the selection trait was examined by testing the animals at different ages as well as in varying conditions. The results indicated that the line difference in thigmotaxis was not affected by age at the time of testing, and it also persisted in the different OF testing situations as well as during pregnancy and lactation. The examination of a possible coselection of other characteristics revealed that the more thigmotactic HOFT mice lived longer than the less thigmotactic LOFT mice. In addition, the HOFT mice tended to rear and explore less than the LOFT mice, supporting the general assumption that emotionality and exploration are inversely related. The two lines did not generally differ in ambulation and defecation, that is, in the traditional OF indexes of emotionality, conforming to the suggestion that emotionality is a multidimensional construct. The effects of sex on different OF parameters were also assessed, with the results suggesting that among the HOFT and LOFT lines, the female mice were more emotional than the male mice. The examination of the temporal changes in the HOFT and LOFT lines’ OF behavior revealed some contradictory findings that also partially conflicted with general assumptions. Although this study did not show prominent differences in maternal responsiveness between the HOFT and LOFT mothers, the results suggested that the line divergence in emotionality was more pronounced in the presence of a pup after parturition than during pregnancy. The present study clearly demonstrates that OF thigmotaxis is a strong characteristic for producing two diverging lines of mice. The difference in thigmotaxis between the selectively bred HOFT and LOFT mice seemed to be a stable and robust feature of these animals, and it appeared to stem from a genetic background.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Thisresearch deals with the dynamic modeling of gas lubricated tilting pad journal bearings provided with spring supported pads, including experimental verification of the computation. On the basis of a mathematical model of a film bearing, a computer program has been developed, which can be used for the simulation of a special type of tilting pad gas journal bearing supported by a rotary spring under different loading conditions time dependently (transient running conditions due to geometry variations in time externally imposed). On the basis of literature, different transformations have been used in the model to achieve simpler calculation. The numerical simulation is used to solve a non-stationary case of a gasfilm. The simulation results were compared with literature results in a stationary case (steady running conditions) and they were found to be equal. In addition to this, comparisons were made with a number of stationary and non-stationary bearing tests, which were performed at Lappeenranta University of Technology using bearings designed with the simulation program. A study was also made using numerical simulation and literature to establish the influence of the different bearing parameters on the stability of the bearing. Comparison work was done with literature on tilting pad gas bearings. This bearing type is rarely used. One literature reference has studied the same bearing type as that used in LUT. A new design of tilting pad gas bearing is introduced. It is based on a stainless steel body and electron beam welding of the bearing parts. It has good operation characteristics and is easier to tune and faster to manufacture than traditional constructions. It is also suitable for large serial production.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Työn tavoite oli kehittää karakterisointimenetelmät kalkkikiven ja polttoaineen tuhkan jauhautumisen ennustamiselle kiertoleijukattilan tulipesässä. Kiintoainekäyttäytymisen karakterisoinnilla ja mallintamisella voidaan tarkentaa tulipesän lämmönsiirron ja tuhkajaon ennustamista. Osittain kokeelliset karakterisointimenetelmät perustuvat kalkkikiven jauhautumiseen laboratoriokokoluokan leijutetussa kvartsiputkireaktorissa ja tuhkan jauhatumiseen rotaatiomyllyssä. Karakterisointimenetelmät ottavat huomioon eri-laiset toimintaolosuhteet kaupallisen kokoluokan kiertoleijukattiloissa. Menetelmät kelpoistettiin kaupallisen kokoluokan kiertoleijukattiloista mitattujen ja fraktioittaisella kiintoainemallilla mallinnettujen taseiden avulla. Kelpoistamistaseiden vähäisyydestä huolimatta karakterisointimenetelmät arvioitiin virhetarkastelujen perusteella järkeviksi. Karakterisointimenetelmien kehittämistä ja tarkentamista tullaan jatkamaan.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tämä työ on tehty yhteistyössä kansainvälisen metsäteollisuusyrityksen Stora Enson kanssa. Työ on osa Stora Enson strategiaa kehitettäessä uusia ja innovatiivisia pakkausmateriaaleja ja ratkaisuja joustopakkausmarkkinoille. Työn päätavoitteina oli selvittää, millaisia odotuksia tuotemerkkienomistajilla ja jatkojalostajilla on joustopakkauksista ja kuinka pakkausten ostopäätökset syntyvät monitahoisessa liikeympäristössä. Työn teoreettinen viitekehys jaettiin kahteen osaan. Asiakasodotuksia lähestyttiin tutkimalla eri palvelu- ja tuotelaadun ulottuvuuksia, ja teollisuuden ostokäyttäytymistä tutkittiin organisaatioiden ostokäyttämistä kuvaavien mallien avulla. Työn empiirisessä osuudessa käytettiin laadullista tutkimusmenetelmää käsittäen asiakashaastatteluja lähinnä Yhdysvalloissa. Haastateltavat yritykset koostuivat maailman johtavista kuluttajatuotteita valmistavista yrityksistä sekä jatkojalostajista. Tutkimustulosten mukaan odotukset pakkauksista liittyvät lähinnä tuotteen suojaamiseen sekä myynnin edistämiseen. Pääodotuksina on myös saada mahdollisimman edullisia papereita, mahdollisimman hyvillä barrier- ja paino-ominaisuuksilla. Tutkimustulokset osoittavat myös, että paperiyhtiöt ovat epäonnistuneet tekemään itseään tunnetuksi teollisuudelle ja heidän odotetaan olevan tulevaisuudessa aggressiivisempia ja innovatiivisempia. Tuotemerkkienomistajat ostavat pakkaukset ja pakkausmateriaalit normaalisti mieluiten jatkojalostajiensa kautta, mutta silti he toivovat yhteistyötä paperintoimittajien kanssa kunhan vain myös jatkojalostajat sisällytetään toimintaan mukaan.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Social information processing (SIP; Crick & Dodge, 1994) and social-cognitive learning theories have been often used to understand children’s problem behaviors, such as aggression. According to these theories, children’s thinking guides their subsequent behaviors. Although most of us agree that social behavior and underlying thought processes are context-dependent, personality and social development researchers have usually engaged in searching for stable patterns of dispositions and behaviors, ignoring (or treating as error) the variance across different situations and relationship types. This, however, can result in erroneous conclusions and question the interpretation of previous findings. Four studies were conducted to explore the influence of relationship context on children’s social-cognitive evaluations and behavior. Samples were fourth to sixth graders from Estonia and Finland. Social cognitions were assessed by presenting children with hypothetical vignettes where the previously identified relationship partner’s behavior had a negative consequence for the child (Studies I, II, and IV), followed by questions measuring different social-cognitive processes (e.g., hostile attributions, behavioral strategies, outcome expectations and self-efficacy beliefs for aggression). In addition, in Studies II and IV, children provided information about their behavior within a specific relationship context. In Study III, an affective priming paradigm was employed where participants were presented with a short display of photographs of children’s liked and disliked classmates, and unknown peers. The results of this thesis suggest that children’s thinking and behavior are largely influenced by the affective valence of the relationship. Moreover, cognitions guide behavior within the relationship. The current findings offer a fruitful avenue for studying the heterogeneity of peer interactions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Nowadays the Finnish-Russian electric energy interaction is carried out through the back-to-back DC Vyborg substation and several power plants working synchronously with Finnish power system. Constant amount of energy flows in one direction — from Russia to Finland. But the process of electricity market development in Russian energy system makes the new possibilities of electrical cooperation available. The goal of master's thesis is to analyze the current state and possible evolution trends of North-West Russian system in relation with future possible change in power flow between Russia and Finland. The research is done by modelling the market of North-West Russia and examination of technical grid restrictions. The operational market models of North-West region of Russia for the years 2008 and 2015 were created during the research process. The description of prepared market models together with modelling results and their analysis are shown in the work. The description of power flow study process and results are also presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Transcription factors play a crucial role in the regulation of cell behavior by modulating gene expression profiles. Previous studies have described a dual role for the AP-1 family transcription factor c-Jun in the regulation of cellular fate. In various cell types weak and transient activations of c-Jun N-terminal kinase (JNK) and c-Jun appear to contribute to proliferation and survival, whereas strong and prolonged activation of JNK and c-Jun result in apoptosis. These opposite roles played by c-Jun are cell type specific and the molecular mechanisms defining these antonymous c-Jun-mediated responses remain incompletely understood. c-Jun activity in transformed cells is regulated by signalling cascades downstream of oncoproteins such as Ras and Raf. In addition, the pro-proliferative role and the survival promoting function for c-Jun has been described in various cancer models. Furthermore, c-Jun was described to be overexpressed in different cancer types. However, the molecular mechanisms by which c-Jun exerts these oncogenic functions are not all clearly established. Therefore it is of primary interest to further identify molecular mechanisms and functions for c-Jun in cancer. Regulation of gene expression is tightly dependent on accurate protein-protein interactions. Therefore, co-factors for c-Jun may define the functions for c-Jun in cancer. Identification of protein-protein interactions promoting cancer may provide novel possibilities for cancer treatment. In this study, we show that DNA topoisomerase I (TopoI) is a transcriptional co-factor for c-Jun. Moreover, c-Jun and TopoI together promote expression of epidermal growth factor receptor (EGFR) in cancer cells. We also show that the clinically used TopoI inhibitor topotecan reduces EGFR expression. Importantly, the effect of TopoI on EGFR transcription was shown to depend on c-Jun as Jun-/- cells or cells treated with JNK inhibitor SP600125 are resistant to topotecan treatment both in regulation of EGFR expression and cell proliferation. Moreover, c-Jun regulates the nucleolar localization and the function of the ribonucleic acid (RNA) helicase DDX21, a previously identified member of c-Jun protein complex. In addition, c-Jun stimulates rRNA processing by supporting DDX21 rRNA binding. Finally, this study characterizes a DDX21 dependent expression of cyclin dependent kinase (Cdk) 6, a correlation of DDX21 expression with prostate cancer progression and a substrate binding dependency of DDX21 nucleolar localization in prostate cancer cells. Taken together, the results of this study validate the c-Jun-TopoI interaction and precise the c-Jun-DDX21 interaction. Moreover, these results show the importance for protein-protein interaction in the regulation of their cellular functions in cancer cell behavior. Finally, the results presented here disclose new exciting therapeutic opportunities for cancer treatment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper is a literature review which describes the construction of state of the art of permanent magnet generators and motors constructing and discusses the current and possible application of these machines in industry. Permanent magnet machines are a well-know class of rotating and linear electric machines used for many years in industrial applications. A particular interest for permanent magnet generators is connected with wind mills, which seem to be becoming increasingly popular nowadays. Geared and direct-driven permanent magnet generators are described. A classification of direct-driven permanent magnet generators is given. Design aspects of permanent magnet generators are presented. Permanent magnet generators for wind turbines designs are highlighted. Dynamics and vibration problems of permanent magnet generators covered in literature are presented. The application of the Finite Element Method for mechanical problems solution in the field of permanent magnet generators is discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this thesis, "Human behavior on the Internet", the human anxiety is conceptualized. The following questions have guided the writing of the thesis: How humans behave with the Internet technology? What goes in their mind? What kinds of behaviors are shown while using the Internet? What is the role of the content on the Internet and especially what are the types of anxiety behavior on the Internet? By conceptualization this thesis aims to provide a model for studying whether humans show signs of less or exacerbated anxiety while using the Internet. The empirical part of this thesis was built on new developed model and user study that utilizes that model. For the user study, the target users were divided into two groups based on their skill level. The user study used both qualitative and quantitative research methods. The qualitative research was conducted using interviews and observational analysis. The quantitative research was conducted in three iterations by using questionnaires and surveys. These results suggest that the significance of human on using technology would be integral part of such a study. The study also suggests that Internet has lulled humans with the sense of dependency to greater extent. In particular, the results identified seven main areas of human anxiety. These forms of anxiety require further studies to encompass human anxiety in more detail.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pienipainoisen keskosen ja äidin varhainen suhde: Lapsen, äidin ja dyadisten muuttujien vaikutus Tämän tutkimuksen tavoitteena oli tutkia keskosvauvan ja äidin varhaista suhdetta. Tutkimuksessa selvitettiin myös vauvan itkukäyttäytymisen, vauvan sylissä olon ja äidin masentuneisuuden yhteyttä äidin ja keskosvauvan varhaiseen suhteeseen. Tutkimusryhmät koostuivat 32:sta (tutkimus I-II) ja 38:sta (tutkimus III-IV) keskosena syntyneestä vauvasta (syntymäpaino < 1501 g tai GI < 32 viikkoa) sekä 46:sta täysiaikaisena syntyneestä terveestä verrokkivauvasta. Lapsen ja äidin vuorovaikutusta arvioitiin 6 ja 12 kuukauden iässä (korjattu ikä) PCERAmenetelmällä. Äidin mielikuvia lapsestaan tutkittiin WMCI-haastattelulla, kun lapsi oli 12 kuukautta. Baby Day Diary -menetelmää käytettiin vauvan itkukäyttäytymisen ja sylissä olon keston mittaamisessa vauvan ollessa 5 kuukautta. Äidin masentuneisuutta arvioitiin EDPS-lomakkeella, kun lapsi oli 6 kuukautta. Tulokset osoittivat, että turvallisten kiintymyssuhdemielikuvien määrä tai vuorovaikutuksen laatu eivät keskosvauvan äideillä eronneet täysiaikaisina syntyneiden vauvojen äitien vastaavista. Ryhmien välillä ei löytynyt eroja myöskään dyadisen vuorovaikutuksen laadussa. Keskosena syntyneet lapset olivat kuitenkin vetäytyvämpiä ja heillä oli laadullisesti heikommat keskittymisen ja leikin taidot vuorovaikutustilanteessa 12 kuukauden iässä täysiaikaisina syntyneisiin lapsiin nähden. Lisäksi äidin masentuneisuus ja lapsen pitkittynyt itkuisuus olivat negatiivisessa yhteydessä vuorovaikutuksen laatuun keskosvauvojen ryhmässä. Vauvan itkukertojen määrän, sylissä olon keston sekä äidin ja vauvan vuorovaikutuksen laadun välillä löytyi positiivinen yhteys ainoastaan keskosena syntyneiden lasten ryhmässä. Tulostemme perusteelle toteamme, että lapsen ennenaikainen syntymä itsessään ei näytä muodostavan riskiä äidin vuorovaikutuksen laadulle tai turvalliselle kiintymyssuhteelle. Yhdessä muiden riskitekijöiden kanssa keskosuus kuitenkin altistaa vauvat ja heidän äitinsä varhaisen vuorovaikutuksen ongelmille. Lisäksi tuloksemme viittaavat siihen, että vauvan itku ja siitä seuraava sylissä olo toimivat suojaavana mekanismina pienipainoisen keskosen ja äidin varhaisessa suhteessa.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study investigates the over and underreaction effects in nine emerging stock markets of Europe. Especially, the possible behavioral aspects behind them are an area of interest. These aspects would link them strongly to behavioral finance. Second, our aim is to provide more evidence of the similar or dissimilar behavior in general among these countries. Third, the possibility to gain abnormal returns from these markets is also under investigation. Data from nine emerging stock market indexes in Europe is gathered from January 1, 1998 to January 1, 2008 to find answers to the stated questions. Studies for the over and underreaction effects are done using a variant of the event study methodology which in this case includes two different calculation methods for the expected returns. Studies are performed using 60 day time intervals. The results between the two different methods used are relatively similar concerning the over and underreaction effects. Another of the methods, however, suggests there to be behavioral aspects behind the effects interpreted. On the other hand, the another method does not support this suggestion. However, a conclusion can be made that the factors driving these countries' behavior are related to their geographical location and to the fact that they are emerging countries.