979 resultados para dynamic execution


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Sertoli cells (SCs), the only somatic cells within seminiferous tubules, associate intimately with developing germ cells. They not only provide physical and nutritional support but also secrete factors essential to the complex developmental processes of germ cell proliferation and differentiation. The SC transcriptome must therefore adapt rapidly during the different stages of spermatogenesis. We report comprehensive genome-wide expression profiles of pure populations of SCs isolated at 5 distinct stages of the first wave of mouse spermatogenesis, using RNA sequencing technology. We were able to reconstruct about 13 901 high-confidence, nonredundant coding and noncoding transcripts, characterized by complex alternative splicing patterns with more than 45% comprising novel isoforms of known genes. Interestingly, roughly one-fifth (2939) of these genes exhibited a dynamic expression profile reflecting the evolving role of SCs during the progression of spermatogenesis, with stage-specific expression of genes involved in biological processes such as cell cycle regulation, metabolism and energy production, retinoic acid synthesis, and blood-testis barrier biogenesis. Finally, regulatory network analysis identified the transcription factors endothelial PAS domain-containing protein 1 (EPAS1/Hif2α), aryl hydrocarbon receptor nuclear translocator (ARNT/Hif1β), and signal transducer and activator of transcription 1 (STAT1) as potential master regulators driving the SC transcriptional program. Our results highlight the plastic transcriptional landscape of SCs during the progression of spermatogenesis and provide valuable resources to better understand SC function and spermatogenesis and its related disorders, such as male infertility.

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World Wide Webin suosiolla on ollut merkittävä vaikutus yhteiskuntaan. WWW-sivut ovat helposti saatavilla ja sisällön tekeminen WWW:hen on helppoa. WWW-ympäristölle myös kehitetään paljon sovelluksia. WWW-sovellusten kehittämiselle ominaista on valinnanvapaus ja nopeuden tavoittelu. WWW-sovellusten ohjelmoinnin mahdollistavat useat toisilleen vaihtoehtoiset tekniikat. Ne eroavat toisistaan suoritusnopeudessa, ominaisuuksien määrässä ja joustavuudessa. Ohjelmoinnissa käytetään apuna useita erilaisia menetelmiä. Apumenetelmiä ovat muun muassa työkalut ja valmiiden komponenttien hyödyntäminen. Valmiit komponentit voivat olla joko ilmaisia, avointa lähdekoodia tai maksullisia. Tämän kandidaatintyön aikana valmistui sovellus, joka piirtää tilastotiedoista kaaviokuvia ja näyttää niitä dynaamisella WWW-sivulla. Sovellus pyrittiin toteuttamaan älykkäästi apumenetelmiä sopivasti hyödyntäen. Sovelluksen kehittämisessä käytettiin apuna sekä ohjelmointityökaluja että valmiita komponentteja. Kaaviokuvien tyypin ja ulkoasun haluttiin olevan käyttäjien muokattavissa. Toisaalta sovelluksen haluttiin olevan helposti laajennettavissa. Vaatimuksiin vastattiin tekemällä kaaviokuvien piirrosta osittain tietokannalla ohjelmoitava.

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The current challenge in a context of major environmental changes is to anticipate the responses of species to future landscape and climate scenarios. In the Mediterranean basin, climate change is one the most powerful driving forces of fire dynamics, with fire frequency and impact having markedly increased in recent years. Species distribution modelling plays a fundamental role in this challenge, but better integration of available ecological knowledge is needed to adequately guide conservation efforts. Here, we quantified changes in habitat suitability of an early-succession bird in Catalonia, the Dartford Warbler (Sylvia undata) ― globally evaluated as Near Threatened in the IUCN Red List. We assessed potential changes in species distributions between 2000 and 2050 under different fire management and climate change scenarios and described landscape dynamics using a spatially-explicit fire-succession model that simulates fire impacts in the landscape and post-fire regeneration (MEDFIRE model). Dartford Warbler occurrence data were acquired at two different spatial scales from: 1) the Atlas of European Breeding Birds (EBCC) and 2) Catalan Breeding Bird Atlas (CBBA). Habitat suitability was modelled using five widely-used modelling techniques in an ensemble forecasting framework. Our results indicated considerable habitat suitability losses (ranging between 47% and 57% in baseline scenarios), which were modulated to a large extent by fire regime changes derived from fire management policies and climate changes. Such result highlighted the need for taking the spatial interaction between climate changes, fire-mediated landscape dynamics and fire management policies into account for coherently anticipating habitat suitability changes of early succession bird species. We conclude that fire management programs need to be integrated into conservation plans to effectively preserve sparsely forested and early succession habitats and their associated species in the face of global environmental change.

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We show that the quasifission paths predicted by the one-body dissipation dynamics, in the slowest phase of a binary reaction, follow a quasistatic path, which represents a sequence of states of thermal equilibrium at a fixed value of the deformation coordinate. This establishes the use of the statistical particle-evaporation model in the case of dynamical time-evolving systems. Pre- and post-scission multiplicities of neutrons and total multiplicities of protons and α particles in fission reactions of 63Cu+92Mo, 60Ni+100Mo, 63Cu+100Mo at 10 MeV/u and 20Ne+144,148,154Sm at 20 MeV/u are reproduced reasonably well with statistical model calculations performed along dynamic trajectories whose slow stage (from the most compact configuration up to the point where the neck starts to develop) lasts some 35×10−21 s.

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Diplomityössä tutkitaan, kuinka Symbian-sovelluskehitystä voitaisiin tehostaa. Työssä esitellään Symbian-käyttöjärjestelmä, sekä pohditaan haasteita ja rajoitteita joita Symbian sovelluskehityksessä kohdataan. Myöskin jo olemassa olevia kehitystapoja pohditaan työn tavoitteen kannalta. Symbian-sovelluskehityksessä tehdään toistuvasti samoja asioita. Koska Symbian on avoin käyttöjärjestelmä, sovelluskehittäjiä on paljon. Tehokkaamman kehitystavan löytäminen säästäisi paljon resursseja. Tällä hetkellä perinteiset ohjelmointitavat näyttävät olevan suosituin tapa kehittää sovelluksia. Kuitenkin on jo olemassa useita ratkaisuja, jotka pyrkivät tehostamaan sovelluskehitystä, mikä todistaa tarpeen kehittää tehokkuutta. Työssä toteutettu systeemi ajaa Symbian sovelluksia XML-määrityksen pohjalta. Kun käytetään XML-määritystä C++-koodin sijasta, sovelluskehitys muuttuu. Näiden muutosten täytyy kuitenkin olla myönteisiä, eivätkä ne saa haitata ohjelmiston laatua tai käytettävyyttä.

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Tutkielman tavoitteena oli selvittää dynaamisten kyvykkyyksien teorian kehittymistä ja nykytilaa. Työssä tarkastellaan myös mahdollisuuksia yhdistää reaalioptioajattelua ja dynaamisten kyvykkyyksien teoriaa. Tutkielma on toteutettu teoreettisena kirjallisuuskatsauksena. Dynaamisten kyvykkyyksien teorian mukaan muuttuvassa toimintaympäristössä yritysten kilpailuetu perustuu kykyyn rakentaa, yhdistää ja muokata resursseja ja kyvykkyyksiä. Yritysten täytyy pystyä löytämään, sulauttamaan ja muuntamaan tietoa voidakseen tunnistaa uusia mahdollisuuksia ja pystyäkseen reagoimaan niihin. Tutkielma tuo esille uusia yhteyksiä dynaamisten kyvykkyyksien teorian ja yritysten käyttäytymisen välillä. Reaalioptioajattelu auttaa tunnistamaan yrityksen rajojen määrittämiseen vaikuttavia tekijöitä. Työssä tehdään ehdotuksia dynaamisten kyvykkyyksien teorian jatkotutkimusta varten.

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This paper describes the fluctuations of temporal criteria dynamics in the context of professional sport. Specifically, we try to verify the underlying deterministic patterns in the outcomes of professional basketball players. We use a longitudinal approach based on the analysis of the outcomes of 94 basketball players over ten years, covering practically players" entire career development. Time series were analyzed with techniques derived from nonlinear dynamical systems theory. These techniques analyze the underlying patterns in outcomes without previous shape assumptions (linear or nonlinear). These techniques are capable of detecting an intermediate situation between randomness and determinism, called chaos. So they are very useful for the study of dynamic criteria in organizations. We have found most players (88.30%) have a deterministic pattern in their outcomes, and most cases are chaotic (81.92%). Players with chaotic patterns have higher outcomes than players with linear patterns. Moreover, players with power forward and center positions achieve better results than other players. The high number of chaotic patterns found suggests caution when appraising individual outcomes, when coaches try to find the appropriate combination of players to design a competitive team, and other personnel decisions. Management efforts must be made to assume this uncertainty.

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We present molecular dynamics simulations of a simple model for polymer melts with intramolecular barriers. We investigate structural relaxation as a function of the barrier strength. Dynamic correlators can be consistently analyzed within the framework of the mode coupling theory of the glass transition. Control parameters are tuned in order to induce a competition between general packing effects and polymer-specific intramolecular barriers as mechanisms for dynamic arrest. This competition yields unusually large values of the so-called mode coupling theory exponent parameter and rationalizes qualitatively different observations for simple bead-spring and realistic polymers. The systematic study of the effect of intramolecular barriers presented here also establishes a fundamental difference between the nature of the glass transition in polymers and in simple glass formers.

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BACKGROUND: Mitogen activated protein kinases (MAPK) play an essential role in integrating extra-cellular signals and intra-cellular cues to allow cells to grow, adapt to stresses, or undergo apoptosis. Budding yeast serves as a powerful system to understand the fundamental regulatory mechanisms that allow these pathways to combine multiple signals and deliver an appropriate response. To fully comprehend the variability and dynamics of these signaling cascades, dynamic and quantitative single cell measurements are required. Microscopy is an ideal technique to obtain these data; however, novel assays have to be developed to measure the activity of these cascades. RESULTS: We have generated fluorescent biosensors that allow the real-time measurement of kinase activity at the single cell level. Here, synthetic MAPK substrates were engineered to undergo nuclear-to-cytoplasmic relocation upon phosphorylation of a nuclear localization sequence. Combination of fluorescence microscopy and automated image analysis allows the quantification of the dynamics of kinase activity in hundreds of single cells. A large heterogeneity in the dynamics of MAPK activity between individual cells was measured. The variability in the mating pathway can be accounted for by differences in cell cycle stage, while, in the cell wall integrity pathway, the response to cell wall stress is independent of cell cycle stage. CONCLUSIONS: These synthetic kinase activity relocation sensors allow the quantification of kinase activity in live single cells. The modularity of the architecture of these reporters will allow their application in many other signaling cascades. These measurements will allow to uncover new dynamic behaviour that previously could not be observed in population level measurements.

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Tutkielman tavoitteena on määritellä keskeiset ja sopivat asiakasportfoliomallit ja asiakasmatriisit asiakassuhteen määrittämiseen. Tutkimus keskittyy asiakassuhteen arvottamiseen ja avainasiakkaiden määrittämiseen kohdeyrityksessä. Keskeisimmät ja sopivimmat asiakasportfliomallit huomioidaan asiakkaiden arvioinnissa. Tutkielman teoriaosassa esitellään tunnetuimmat ja käytetyimmät asiakasportfoliomallit ja matriisit alan kirjallisuuden perusteella. Tämän lisäksi asiakasportfoliomalleihin yhdistetään näkökulmia suhdemarkkinoinnin, asiakkuuksien johtamisen ja tuoteportfolioiden teorioista. Keskeisimmät kirjallisuuden lähteet ovat johtamisen ja markkinoinnin alalta. Tutkielman empiriaosassa esitellään kohdeyritys ja sen tämän hetkinen asiakassuhteiden johtamiskäytäntö. Lisäksi tehdään parannusehdotuksia kohdeyrityksen nykyiseen asiakassuhteiden arvottamismenetelmään jotta asiakassuhteiden arvon laskeminen vastaisi mahdollisimman hyvin kohdeyrityksen nykyisiä tarpeita. Asiakassuhteen arvon määrittämiseksi käytetään myös fokusryhmähaastattelua. Avainasiakkaat määritellään ja tilannetta havainnollistetaan sijoittamalla avainasiakkaat asiakasportfolioon.

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The silicon photomultiplier (SiPM) is a novel detector technology that has undergone a fast development in the last few years, owing to its single-photon resolution and ultra-fast response time. However, the typical high dark count rates of the sensor may prevent the detection of low intensity radiation fluxes. In this article, the time-gated operation with short active periods in the nanosecond range is proposed as a solution to reduce the number of cells fired due to noise and thus increase the dynamic range. The technique is aimed at application fields that function under a trigger command, such as gated fluorescence lifetime imaging microscopy.

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Iberia underwent intraplate deformation during the Mesozoic and Cenozoic. In eastem Ibena, compression took place during the Palaeogene and early Miocene, giving rise to the Iberian Chain, and extension started during the early Miocene in the coastal areas and the Valencia trough; during early Miocene compression continued in the western Iberian Chain whereas extension had started in the eastern Iberian Chain. From the kinematic data obtained from the major compressional and extensional structures formed dunng the Cenozoic, a simple dynamic model using Bott's (1959) formula is presented. The results show that both extension and compression may have been produced assuming a main horizontal stress-axis approximately N-S, in a similar direction that the convergence between Europe, Ibena and Afnca dunng the Cenozoic.

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The research described in this thesis examines the characteristics, the benefits and the challenges associated with the implementation of management accounting systems in the field of Corporate Social Responsibility (CSR). Applied to the CSR context, management accounting relates to the identification, elaboration and communication of information about an organization's interactions with the society and the environment. Based on this information, firms are able to make decisions to achieve social and environmental objectives and provide evidence justifying the benefits and the costs of such actions. The study begins by focusing on green management and exploring the characteristics of Environmental Management Accounting (EMA) systems within firms. The first chapter informs the reader about the growing body of EMA research and reveals unexplored relevant aspects that need to be further investigated. The work also emphasizes the importance of developing new theoretical hypotheses and appropriate research designs to empirically tackle new aspects of EMA and gain understanding on the use of these practices. Subsequently, given the acknowledged importance of control systems in influencing the behaviour of individuals within organizations, the remaining two chapters of the dissertation focus on the functioning of CSR-linked incentives assigned to employees in the form of compensation plans. The second chapter examines the determinants influencing corporate provision of incentives for the attainment of environmental targets. Empirical analysis of a sample of international firms reveals that companies are likely to use green incentives as mechanisms to increase the efficacy in contracting with their employees as well as to respond to social influences. Finally, the third chapter investigates the effectiveness of contracting associated with the use of CSR-linked executive compensation. Empirical analysis of a sample of US-based companies shows that corporate choice to tie senior executives' pay to CSR targets promotes the firm's CSR performance. Cette thèse examine les caractéristiques, avantages et défis associés à l'utilisation des systèmes de contrôle de gestion dans le domaine de la Responsabilité Sociale des Entreprises (RSE). Dans le contexte de la RSE, les activités du contrôle de gestion impliquent l'identification, l'élaboration et la communication d'informations qui concernent les interactions des organisations avec la société et l'environnement. Avec ces informations les entreprises sont en mesure de prendre des décisions visant à atteindre les objectifs sociaux et environnementaux de l'organisation et de documenter les bénéfices et coûts de ces actions. Dès le début, la thèse se concentre sur les caractéristiques des systèmes de contrôle de gestion environnementale au sein des entreprises. Le premier chapitre passe en revue la littérature existante et révèle des aspects inexplorés. Pour ce faire, le travail suggère le développement de nouvelles théories ainsi que l'utilisation de méthodes appropriées. Ces dernières doivent permettre d'aborder empiriquement de nouveaux aspects des systèmes de contrôle environnemental et faciliter la compréhension sur l'utilisation de ces pratiques. Considérant l'importance des systèmes de contrôle pour influencer le comportement des individus au sein des organisations, la suite du travail se concentre sur le fonctionnement des contrats de rémunération des employées liées aux résultats de la RSE. Plus particulièrement, le deuxième chapitre examine les facteurs qui influencent la décision des entreprises d'assigner des objectifs environnementaux aux employées. L'analyse empirique d'un échantillon d'entreprises internationales montre que les entreprises sont susceptibles d'utiliser des mécanismes incitatifs écologiques pour augmenter l'efficacité des contrats ainsi que pour répondre aux influences sociales. Finalement, le troisième chapitre analyse l'efficacité des contrats de rémunération des dirigeants liés aux résultats de la RSE. L'analyse empirique d'un échantillon de sociétés américaines indique que le choix de l'entreprise de lier la rémunération des dirigeants à des objectifs de la RSE favorise la performance RSE de l'organisation.